A radiation shielding cask apparatus that comprises a cask body, a bottom lid, and a plurality of canister support elements. The cask body defines a cavity configured to receive a canister containing spent nuclear fuel. The bottom lid detachably coupled to the cask body to enclose a bottom end of the cavity. The plurality of canister support elements coupled to a bottom portion of the cask body and alterable between: (1) a canister support state in which the canister support elements protrude into the cavity, support the canister, and prohibit the canister from being removed from the cavity via the bottom end of the cavity; and (2) a canister unloading state in which the canister support elements are retracted and allow the canister to be removed from the cavity via the bottom end of the cavity when the bottom lid is removed from the cask body.
A nuclear fuel decay heat utilization system usable for space heating in one embodiment comprises a nuclear generation plant building housing a spent fuel pool containing submerged fuel assemblies which emit decay heat that heats the pool. Plural fluidly isolated but thermally coupled heat removal systems comprising pumped flow loops operate in tandem to absorb thermal energy from the heated pool water, and transfer the thermal energy through the systems in a cascading manner form one to the next to a final external heat sink outside the plant building from which the heat is rejected to the ambient environment. A programmable controller operably regulates the intake and flowrate of water from the heat sink into the heat removal systems and monitors ambient air temperature inside to building. The flowrate is regulated to maintain a preprogrammed building setpoint air temperature by increasing fuel pool water temperature to a maximum permissible limit.
An automated welding system for sealing high level radioactive waste containers in the field at the nuclear plant site. The system includes a programmable portable robotic welder comprising a multi-jointed articulating robotic arm. A welding head operable to form a weld is mounted to the arm. Operation of the robotic welder and ancillary components is controlled by a programmable controller which implements a welding plan. In one embodiment, a circumferentially-extending lid-to-shell hermetic seal weld may be formed by the robotic welder. The weld is completed in multiple welding passes through the weld joint between the lid and shell guided by an automated joint tracking sensor linked to the controller. The highly portable robotic welder is detachably mountable on the lid to perform the welding. An automated pivotable cable-conduit management apparatus keeps electrically conductive wiring and flow tubing out of the path of the rotating robotic arm during welding.
A hybrid power generation system in one embodiment comprises a green boiler containing a thermal mass composition operable to store thermal energy, a solar energy collection system which absorbs solar energy to heat a first working fluid and in turn the thermal mass composition, and a power generation system comprising a steam turbine coupled to an electric generator to produce electricity and a nuclear steam supply system which convert a second working fluid comprising water from liquid to steam. Steam output by the nuclear steam supply system flows through the green boiler and is heated by absorbing heat from the thermal mass composition to increase the enthalpy of the steam and concomitantly electric power output from the turbine-generator. The nuclear steam supply system and green boiler may be retrofit to replace existing fossil fuel steam generation systems while retaining the energy conversion part of the fossil power plant.
F24S 80/20 - Working fluids specially adapted for solar heat collectors
F01D 15/10 - Adaptations for driving, or combinations with, electric generators
F22B 1/16 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour
F24S 10/30 - Solar heat collectors using working fluids with means for exchanging heat between two or more working fluids
F24S 20/20 - Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
F24S 60/30 - Arrangements for storing heat collected by solar heat collectors storing heat in liquids
F24S 70/60 - Details of absorbing elements characterised by the structure or construction
F03G 6/06 - Devices for producing mechanical power from solar energy with solar energy concentrating means
F24S 80/30 - Arrangements for connecting the fluid circuits of solar heat collectors with each other or with other components, e.g. pipe connectionsFluid distributing means, e.g. headers
5.
REACTOR VESSEL WELL FOR SUPPORTING A NUCLEAR REACTOR IN A SUBTERRANEAN CAVITY
A system for supporting and housing a nuclear reactor in a subterranean vault comprises a concrete base mat and sidewall defining a subterranean cavity. A reactor pressure vessel (RPV) containing the fuel core is disposed in the subterranean cavity and includes radially-extending support trunnions coupled to the RPV shell. Each trunnion is received in a corresponding support recess in the sidewall interior surface to support the RPV in a vertically cantilevered suspended manner. A seismic stabilizer anchored in the base mat is positioned to engage the bottom head of the RPV during a seismic event to arrest lateral movement of the RPV. A metal liner system for the subterranean cavity includes inner and outer liners that cover the concrete base mat and sidewall. Thermal insulation interposed between the liners reduces heat transmission to the concrete from the RPV when operating to maintain safe concrete temperatures.
A steam generator enclosure system for a nuclear power generation plant includes a concrete slab defining an operating deck and an enclosure disposed on the slab. The enclosure is formed by a double-walled sidewall comprising an inner and outer shell spaced radially apart defining an annular space therebetween filled with concrete for radiation shielding. Vertically-extending rib plates in the annular space couple the inner and outer shells together. Downward extensions of the rib plates from the sidewall form anchors embedded in the concrete slab. A steam generator vessel seated on the slab is disposed inside an internal cavity formed by the sidewall. Seismic restraints provided at multiple elevations couple the vessel to the sidewall in a manner which accommodates thermal expansion/contraction of the vessel. In one embodiment, the enclosure may have a modular construction formed by an assemblage of shop-fabricated wall section modules erected on site and filled with concrete.
G21C 15/12 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements from pressure vesselArrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements from containment vessel
A vertical bundle air-cooled heat exchanger, a finned tube assembly for an air cooled condenser and method for forming the same, and a system for removing thermal energy generated by radioactive materials. In one aspect, an air cooled condenser sized for industrial and commercial application includes an inlet steam distribution header for conveying steam, a condensate outlet header for conveying condensate, an array of tube bundles each having a plurality of finned tube assemblies having a bare steel tube with an exposed outer surface and a set of aluminum fins brazed directly onto the tube by a brazing filler metal. The steel tubes may be spaced apart by the aluminum fins and have an inlet end fluidly coupled to the inlet steam distribution header and an outlet end fluidly coupled to the outlet header. A forced draft fan may be arranged to blow air through the tube bundles.
F28B 1/06 - Condensers in which the steam or vapour is separated from the cooling medium by walls, e.g. surface condenser using air or other gas as the cooling medium
F28B 9/10 - Auxiliary systems, arrangements, or devices for extracting, cooling, and removing non-condensable gases
F28D 1/02 - Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with the heat-exchange conduits immersed in the body of fluid
F28D 7/10 - Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged one within the other, e.g. concentrically
F28F 1/00 - Tubular elementsAssemblies of tubular elements
F28F 1/16 - Tubular elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally the means being integral with the element, e.g. formed by extrusion
F28F 1/20 - Tubular elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally the means being attachable to the element
A hybrid solar energy power generation system includes a thermal energy storage (TES) vessel containing a thermal mass composition operable to store thermal energy, a concentrated solar power (CSP) system, and a photovoltaic (PV) power system. The CSP system heats a first working fluid flowing in first closed flow loop via a solar collector. The heated first working fluid recirculates through the TES vessel to heat the TM composition. The PV power system generates electricity which can be delivered directly to the electric power grid or alternatively when grid demand drops energizes can electric heaters to supplement heating the first working fluid. This increases the temperature and enthalpy of the first working fluid to store additional thermal energy in the TM composition. The TES vessel is operable to heat a second working fluid to produce steam usable for industrial processes, district heating, or to power a Rankine power generation cycle.
F03G 6/06 - Devices for producing mechanical power from solar energy with solar energy concentrating means
F24S 90/00 - Solar heat systems not otherwise provided for
F24S 20/20 - Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
F22B 1/00 - Methods of steam generation characterised by form of heating method
H02S 10/10 - PV power plantsCombinations of PV energy systems with other systems for the generation of electric power including a supplementary source of electric power, e.g. hybrid diesel-PV energy systems
H02S 10/20 - Systems characterised by their energy storage means
A passively cooled stackable nuclear waste storage system may include a pair of vertically stacked radiation-shielded nuclear waste storage casks. Each cask has a cavity which holds a nuclear waste canister containing spent nuclear fuel or other high-level radioactive wastes. The lower cask may be founded on an above-grade concrete pad. The upper cask is vertically stacked on and detachably coupled to the lower cask. The upper cask comprises a perforated baseplate which establishes fluid communication between cavities of both casks and is configured to prevent radiation shine. One or both casks may include air inlet vents configured to draw ambient ventilation air into each respective cask cavity for cooling the nuclear waste. In operation, air is drawn inward into each cask cavity independently. Air heated in the lower cask rises into the upper cask where it mixes with air drawn into the upper cask and is returned to atmosphere.
A natural passively cooled ventilated cask includes a cavity which holds a canister containing heat and radiation emitting spent nuclear fuel assemblies. Cooling air inlet ducts draw ambient cooling air inwards into a lower portion of the cavity. The air heated by the canister flows upwards along the canister and is discharged from at least one air outlet duct formed by the cask lid to atmosphere via natural convective thermo-siphon flow. The air inlet ducts or at least one outlet duct in one embodiment may be fitted with an adjustable shutter plate which allows the flowrate of air entering the cask to be increased or decreased to maintain a predetermined canister maximum temperature limit selected in part to prevent the onset of stress corrosion cracking of the canister welds. Other embodiments may use a fixed orifice plate replaceable over time to maintain the minimum temperature.
A power generation system and related method for repowering a fossil-fueled power plant using a carbon-free nuclear steam supply system (NSSS) which replaces the existing fossil plant steam generator which burns fossil fuel such as coal, oil, or natural gas. The existing fossil plant energy conversion system including the turbine-generator (turbogenerator) and auxiliary components of the Rankine cycle is retained. The NSSS may include a small modular reactor (SMR) unit comprising a reactor vessel with nuclear fuel core and steam generator which receives heated primary coolant from the reactor to produce main steam to operate the Rankine cycle. The main steam output by the SMR unit is compressed in a steam compressor to increase its pressure to a level necessary to operate the turbogenerator. The compressor may be operated via a portion of the main steam. An intercooler of the compressor may be used for main steam reheating.
F01K 3/00 - Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein
F01K 3/18 - Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having heaters
F01K 3/26 - Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having heaters with heating by steam
F01K 7/16 - Steam engine plants characterised by the use of specific types of enginePlants or engines characterised by their use of special steam systems, cycles or processesControl means specially adapted for such systems, cycles or processesUse of withdrawn or exhaust steam for feed-water heating the engines being only of turbine type
F01K 13/02 - Controlling, e.g. stopping or starting
A hybrid solar energy power generation system includes a thermal energy storage (TES) vessel containing a thermal mass composition operable to store thermal energy, a concentrated solar power (CSP) system, and a photovoltaic (PV) power system. The CSP system heats a first working fluid flowing in first closed flow loop via a solar collector. The heated first working fluid recirculates through the TES vessel to heat the TM composition. The PV power system generates electricity which can be delivered directly to the electric power grid or alternatively when grid demand drops energizes can electric heaters to supplement heating the first working fluid. This increases the temperature and enthalpy of the first working fluid to store additional thermal energy in the TM composition. The TES vessel is operable to heat a second working fluid to produce steam usable for industrial processes, district heating, or to power a Rankine power generation cycle.
H02S 10/20 - Systems characterised by their energy storage means
F24S 10/70 - Solar heat collectors using working fluids the working fluids being conveyed through tubular absorbing conduits
F24S 20/20 - Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
F24S 20/40 - Solar heat collectors combined with other heat sources, e.g. using electrical heating or heat from ambient air
F24S 23/70 - Arrangements for concentrating solar rays for solar heat collectors with reflectors
F24S 60/10 - Arrangements for storing heat collected by solar heat collectors using latent heat
F24S 80/20 - Working fluids specially adapted for solar heat collectors
H02S 40/44 - Means to utilise heat energy, e.g. hybrid systems producing warm water and electricity at the same time
13.
NUCLEAR WASTE CASK WITH IMPACT PROTECTION, IMPACT AMELIORATION SYSTEM FOR NUCLEAR FUEL STORAGE, UNVENTILATED CASK FOR STORING NUCLEAR WASTE, AND STORAGE AND TRANSPORT CASK FOR NUCLEAR WASTE
A nuclear waste cask with impact protection includes impact limiters comprising deformable energy-absorbing perforated sleeves. An impact amelioration system for nuclear fuel storage components includes impact limiter assemblies at the bottom cask to canister interface including impact limiter plugs frictionally engaging corresponding plug holes formed in the cask closure plate. A nuclear waste fuel storage system includes an unventilated cask including a heavy free-floating radiation shielding lid loosely coupled the top end of the cask in a movable manner via the anchor bosses which provides cask overpressurization protection. A nuclear waste cask includes an axially elongated rectangular cuboid cask body having a cavity for holding nuclear waste materials and cask locking mechanism including first locking protrusions on the lid which are selectively interlockable with mating second locking protrusions on the cask body to lock the lid to the cask body.
A hybrid power generation system in one embodiment comprises a green boiler containing a thermal mass composition operable to store thermal energy, a solar energy collection system which absorbs solar energy to heat a first working fluid and in turn the thermal mass composition, and a power generation system comprising a steam turbine coupled to an electric generator to produce electricity and a nuclear steam supply system which convert a second working fluid comprising water from liquid to steam. Steam output by the nuclear steam supply system flows through the green boiler and is heated by absorbing heat from the thermal mass composition to increase the enthalpy of the steam and concomitantly electric power output from the turbine-generator. The nuclear steam supply system and green boiler may be retrofit to replace existing fossil fuel steam generation systems while retaining the energy conversion part of the fossil power plant.
A solar power generation system includes a thermal energy storage vessel containing a thermal mass composition operable to store thermal energy, solar energy collection system, and power generation system. The collection system comprises a first closed flow loop including a solar collector which absorbs solar energy and heats a first working fluid. The heated first working fluid recirculates through a first closed flow loop through and heats the thermal mass composition. The generation system comprises a second closed flow loop including a turbine-generator. The second closed flow loop recirculates a second working fluid through the thermal mass composition to absorb thermal energy and heat the second working fluid which flows to the turbine and the generator produces electricity. The second working fluid may be water/steam or a compressible gas. The thermal mass composition comprises a mixture of a phase change material such as salt and a metallic material.
F24S 10/20 - Solar heat collectors using working fluids having circuits for two or more working fluids
F24S 10/30 - Solar heat collectors using working fluids with means for exchanging heat between two or more working fluids
F24S 10/50 - Solar heat collectors using working fluids the working fluids being conveyed between plates
F24S 10/70 - Solar heat collectors using working fluids the working fluids being conveyed through tubular absorbing conduits
F24S 20/20 - Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
F24S 20/25 - Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants using direct solar radiation in combination with concentrated radiation
F24S 23/70 - Arrangements for concentrating solar rays for solar heat collectors with reflectors
F24S 23/71 - Arrangements for concentrating solar rays for solar heat collectors with reflectors with parabolic reflective surfaces
A solar power generation system includes a thermal energy storage vessel containing a thermal mass composition operable to store thermal energy, solar energy collection system, and power generation system. The collection system comprises a first closed flow loop including a solar collector which absorbs solar energy and heats a first working fluid. The heated first working fluid recirculates through a first closed flow loop through and heats the thermal mass composition. The generation system comprises a second closed flow loop including a turbine-generator. The second closed flow loop recirculates a second working fluid through the thermal mass composition to absorb thermal energy and heat the second working fluid which flows to the turbine and the generator produces electricity. The second working fluid may be water/steam or a compressible gas. The thermal mass composition comprises a mixture of a phase change material such as salt and a metallic material.
An automatically adjusting seismic restraint system for nuclear fuel storage in one embodiment comprises a free-standing first fuel storage component (FSC) configured to contain nuclear fuel, and a stationary second FSC configured to receive the first fuel storage component. An inter-body gap formed between the FSCs includes at least one seismic restraint assembly. The assembly includes a stationary wedge member fixedly coupled to the second FSC and a movable loose wedge member engaged with and supported in place by the stationary wedge member. The stationary wedge member defines an inclined load bearing surface slideably engaged with a mating inclined load bearing surface of the loose wedge member. During a seismic event or thermal expansion of the first FSC, the first FSC moves towards the second FSC which shrinks the inter-body gap and the loose wedge member is vertically displaced relative to the stationary wedge member while maintaining engagement therewith.
A dry storage systems for radioactive nuclear waste materials may include a double-walled canister system. The canister system may include a canister having a tubular inner shell defining an internal cavity for storing nuclear waste material, a first lid sealably welded to a first end of the inner shell, a primary base plate defining a peripheral edge portion and having an annular closure flange, and an annular full thickness butt weld formed at an abutment joint between the annular closure flange and a second end of the inner shell. The inner shell, first lid, and first end closure may collectively define a sealed primary pressure retention barrier. A tubular outer shell may adjoin the inner shell. The outer shell may be welded to the canister to form a hermetically sealed secondary pressure retention barrier.
A fuel rack for wet storage of nuclear fuel in a fuel pool in one embodiment comprises a baseplate and a cellular body formed of interlocked stacked slotted plates coupled to the baseplate. The body comprises tightly-packed upwardly open cells which each hold a nuclear fuel assembly. Open flux traps are formed between at least some cells which fill with water when the rack is submerged to act as a neutron moderator to control reactivity in the rack. In one embodiment, a flux trap is interspersed between adjacent cells running in a first direction along a first horizontal axis of the rack. However, a flux trap is not interspersed between adjacent cells running in a perpendicular second direction along a second horizontal axis. Other flux trap and cell arrangements are provided. Tension elements extend through some flux traps which compress the stack of plates together for stability.
A power generation system and related method for repowering a fossil-fueled power plant using a carbon-free nuclear steam supply system (NSSS) which replaces the existing fossil plant steam generator which burns fossil fuel such as coal, oil, or natural gas. The existing fossil plant energy conversion system including the turbine-generator (turbogenerator) and auxiliary components of the Rankine cycle is retained. The NSSS may include a small modular reactor (SMR) unit comprising a reactor vessel with nuclear fuel core and steam generator which receives heated primary coolant from the reactor to produce main steam to operate the Rankine cycle. The main steam output by the SMR unit is compressed in a steam compressor to increase its pressure to a level necessary to operate the turbogenerator. The compressor may be operated via a portion of the main steam. An intercooler of the compressor may be used for main steam reheating.
F01K 3/00 - Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein
F01K 3/18 - Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having heaters
F01K 3/26 - Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having heaters with heating by steam
F01K 7/16 - Steam engine plants characterised by the use of specific types of enginePlants or engines characterised by their use of special steam systems, cycles or processesControl means specially adapted for such systems, cycles or processesUse of withdrawn or exhaust steam for feed-water heating the engines being only of turbine type
F01K 13/02 - Controlling, e.g. stopping or starting
21.
SYSTEM AND RELATED METHOD FOR CONVERTING FOSSIL-FUELED GENERATING PLANTS TO CLEAN ENERGY
A power generation system and related method for repowering a fossil-fueled power plant using a carbon-free nuclear steam supply system (NSSS) which replaces the existing fossil plant steam generator which burns fossil fuel such as coal, oil, or natural gas. The existing fossil plant energy conversion system including the turbine-generator (turbogenerator) and auxiliary components of the Rankine cycle is retained. The NSSS may include a small modular reactor (SMR) unit comprising a reactor vessel with nuclear fuel core and steam generator which receives heated primary coolant from the reactor to produce main steam to operate the Rankine cycle. The main steam output by the SMR unit is compressed in a steam compressor to increase its pressure to a level necessary to operate the turbogenerator. The compressor may be operated via a portion of the main steam. An intercooler of the compressor may be used for main steam reheating.
F22B 1/12 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being steam produced by an indirect cyclic process
F22B 1/14 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being steam coming in direct contact with water in bulk or in sprays
22.
High-density subterranean storage system for nuclear fuel and radioactive waste
A passively cooled stackable nuclear waste storage system includes an at least partially below grade cavity enclosure container (CEC) and above grade cask. Each vessel includes a cavity holding a nuclear waste canister containing spent nuclear fuel or other high-level radioactive wastes. The CEC is founded on a below grade concrete base pad and cask is mounted on an above-grade concrete top pad in a vertically stacked arrangement. The upper cask comprises a perforated baseplate which establishes fluid communication between cavities of both casks and is configured to prevent radiation shine. One or both vessels include air inlets which draw ambient cooling air into their respective cavities for cooling the nuclear waste. Air heated in the lower CEC rises into the upper cask through the baseplate where it mixes with air drawn into the cask and is returned to atmosphere. The system increases storage capacity of new or existing facilities.
A container system for radioactive waste and method for using the same is provided. The system includes a canister configured for holding radioactive waste and a lid system. In one embodiment, the lid system comprises a two-part lid assembly including a confinement lid and a shielded lifting lid. The confinement lid is detachably mounted to the confinement lid. In use, the lifting lid supports the confinement lid for lifting and placement on the canister. The lifting lid further shields operators while the confinement lid is mounted to the canister. Thereafter, the lifting lid is removed and may be reused for confinement lid mountings on other canisters. In one embodiment, the confinement lid is bolted to the canister. The canister may be disposed in a protective overpack for transport and storage.
A radioactive nuclear waste storage system includes a cask comprising a hermetically sealed internal cavity configured for holding the waste such as spent nuclear fuel submerged in an inventory of water. One or more pressure surge capacitors disposed inside the cask include a vacuum cavity evacuated to sub-atmospheric conditions prior to storage of fuel in the cask. At least one rupture disk seals a vacuum chamber inside each capacitor. Each rupture disk is designed and constructed to burst at a predetermined burst pressure level occurring inside the cask external to the capacitor. This allows excess cask pressure occurring during a high pressure excursion resulting from abnormal operating conditions to bleed into capacitor, thereby returning the pressure inside the cask to acceptable levels. In one embodiment, the capacitors are located in peripheral regions of the cask cavity adjacent to the circumferential wall of the cask body.
An eddy current testing apparatus and related methods for conducting non-destructive examination of heat exchanger tubes accessible via a heat exchanger tubesheet. The apparatus comprises a motor-driven drive pulley and one or more idler pulleys engageable with the test cable of the test probe to feed out or retract the cable and test head which are insertable into the heat exchanger tube under test. A support bracket of the apparatus includes manually-expandable tube clamps operated by an actuating lever. The clamps include a tubular securement sleeve with expandable portion for insertion into and releasably locking to an anchoring tube in tubesheet. This supports the apparatus from the tubesheet in a cantilevered manner. The idler pulley(s) may be mounted to a pivot arm movable between an inward position to press the cable into engagement with the drive pulley, and an outward position which releases the cable to facilitate setup or takedown.
G21C 17/003 - Remote inspection of vessels, e.g. pressure vessels
G01N 27/90 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
F28F 11/00 - Arrangements for sealing leaky tubes or conduits
26.
EDDY CURRENT TESTING APPARATUS AND RELATED METHODS
An eddy current testing apparatus and related methods for conducting non-destructive examination of heat exchanger tubes accessible via a heat exchanger tubesheet. The apparatus comprises a motor-driven drive pulley and one or more idler pulleys engageable with the test cable of the test probe to feed out or retract the cable and test head which are insertable into the heat exchanger tube under test. A support bracket of the apparatus includes manually-expandable tube clamps operated by an actuating lever. The clamps include a tubular securement sleeve with expandable portion for insertion into and releasably locking to an anchoring tube in tubesheet. This supports the apparatus from the tubesheet in a cantilevered manner. The idler pulley(s) may be mounted to a pivot arm movable between an inward position to press the cable into engagement with the drive pulley, and an outward position which releases the cable to facilitate setup or takedown.
G01N 27/90 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
An impact amelioration apparatus and system comprising a stationary impact limiter containing a deformable impact-cushioning material that can be used as a kinetic energy-absorbing target against a free falling radioactive waste-laden vessel such as a nuclear waste storage and/or transport cask. In one embodiment, the cushioning material may be one or more layers of pervious concrete encased in a metal outer container, which may be hermetically-sealed in some embodiments. The pervious concrete is crushable upon impact by an accidentally dropped free-falling cask to safely decelerate the cask while preserving the structural radiation containment envelope of the cask to prevent release of radiation to the ambient environment. The stationary impact limiter may located on a support surface in an equipment loading area of a nuclear facility, such as a nuclear power generation plant, beneath an overhead lifting apparatus used to move equipment such as casks into and out of the facility.
An impact amelioration apparatus and system comprising a stationary impact limiter containing a deformable impact-cushioning material that can be used as a kinetic energy-absorbing target against a free falling radioactive waste-laden vessel such as a nuclear waste storage and/or transport cask. In one embodiment, the cushioning material may be one or more layers of pervious concrete encased in a metal outer container, which may be hermetically-sealed in some embodiments. The pervious concrete is crushable upon impact by an accidentally dropped free-falling cask to safely decelerate the cask while preserving the structural radiation containment envelope of the cask to prevent release of radiation to the ambient environment. The stationary impact limiter may located on a support surface in an equipment loading area of a nuclear facility, such as a nuclear power generation plant, beneath an overhead lifting apparatus used to move equipment such as casks into and out of the facility.
A green boiler includes a thermal energy storage vessel containing a captive bed of a thermal mass composition operable to store thermal energy, an array of heaters embedded in the mass, and at least one heat exchanger comprising a tube bundle. The heaters in one embodiment may be electric and coupled to an electric power source to heat the thermal mass. The tube bundle comprises tubes embedded in the thermal mass composition which are configured to convey heat transfer fluid (e.g., water or other) through a tube-side of the tubes. In operation, the heat transfer fluid is heated by absorbing stored thermal energy from the thermal mass composition. The thermal mass composition may be heated by power extracted from the power grid during off-peak demand periods in some embodiments. The vessel may produce heated water or steam for district heating, or steam for power generation or industrial uses.
A green boiler includes a thermal energy storage vessel containing a captive bed of a thermal mass composition operable to store thermal energy, an array of heaters embedded in the mass, and at least one heat exchanger comprising a tube bundle. The heaters in one embodiment may be electric and coupled to an electric power source to heat the thermal mass. The tube bundle comprises tubes embedded in the thermal mass composition which are configured to convey heat transfer fluid (e.g., water or other) through a tube-side of the tubes. In operation, the heat transfer fluid is heated by absorbing stored thermal energy from the thermal mass composition. The thermal mass composition may be heated by power extracted from the power grid during off-peak demand periods in some embodiments. The vessel may produce heated water or steam for district heating, or steam for power generation or industrial uses.
A system for transporting radioactive materials which may include a containment vessel, a thermal shield, and an impact limiter. The containment vessel may include a vessel body having a storage cavity for receiving radioactive materials, a lid coupled to an upper portion of the vessel body to enclose a top end of the storage cavity, and a lid seal such as a gasket positioned between the lid and the upper portion of the vessel body. The thermal shield may be positioned over the lid. The first impact limiter may be positioned over the thermal shield. The thermal shield may be resistant to high temperatures and may help to protect the integrity of the lid seal when the system is subjected to high temperatures, such as during a fire condition.
A system for transporting radioactive materials which may include a containment vessel, a thermal shield, and an impact limiter. The containment vessel may include a vessel body having a storage cavity for receiving radioactive materials, a lid coupled to an upper portion of the vessel body to enclose a top end of the storage cavity, and a lid seal such as a gasket positioned between the lid and the upper portion of the vessel body. The thermal shield may be positioned over the lid. The first impact limiter may be positioned over the thermal shield. The thermal shield may be resistant to high temperatures and may help to protect the integrity of the lid seal when the system is subjected to high temperatures, such as during a fire condition.
A containment enclosure for shielding an outer cask containing an inner canister loaded with nuclear waste such as spent fuel rods. The enclosure includes a lower base portion at least partially embedded in a concrete pad and an upper radiation shielding portion defined by a shield jacket coupled to and supported by the lower base portion at a circumferential joint. Cavities of the base and shielding portions collectively define a contiguous containment space for the cask. A portion of the cask resides in each of the base and shielding portions which completely enclose and shield the cask to minimize radiation dosage of personnel in the environment surrounding the cask. The cask is cooled by a natural convectively-driven ambient cooling air ventilation system including air inlets at the circumferential joint of the enclosure. The concrete pad may be part of a spent nuclear fuel storage installation comprising plural cask containment enclosures.
An air-cooled condenser system for steam condensing applications in a power plant Rankine cycle includes an air cooled condenser having a plurality of interconnected modular cooling cells. A method for forming an axial flow baffle for a shell and tube heat exchanger includes providing a baffle workpiece, locating a centerpoint of a first axial flow tube aperture, drilling flow holes around the centerpoint of the flow aperture, and drilling a central tube hole at the centerpoint. A method of cooling high level waste includes surrounding a cask comprising an external surface and an internal storage cavity containing the high level radioactive waste which emits heat with a cooling water header; and discharging cooling water radially inwards from the cooling water header onto the external surface of the cask from the plurality of water dispensing outlets arranged on the cooling water header.
F28B 1/06 - Condensers in which the steam or vapour is separated from the cooling medium by walls, e.g. surface condenser using air or other gas as the cooling medium
G21F 5/12 - Closures for containersSealing arrangements
A nuclear waste cask in one embodiment includes an axially elongated cask body defining a longitudinally-extending opening forming an entrance to an internal storage cavity of the cask configured for holding radioactive nuclear waste materials. A closure lid detachably coupled to the cask body at the top opening seals the cavity. A cask locking mechanism includes a plurality of first locking protrusions spaced apart on the lid which are selectively interlockable with a plurality of second locking protrusions spaced apart on the cask body to lock the lid to the cask body. The first locking protrusions may be disposed on slideable locking bars moveable between locked and unlocked positions while the lid remains stationary on the cask body. Hydraulic or pneumatic actuators may be used to change position of the locking bars. The cask and lid may include other features such as impact absorbers and lifting elements.
A dry storage systems for radioactive nuclear waste materials may include a double-walled canister system. The canister system may include a canister having a tubular inner shell defining an internal cavity for storing nuclear waste material, a first lid sealably welded to a first end of the inner shell, a primary base plate defining a peripheral edge portion and having an annular closure flange, and an annular full thickness butt weld formed at an abutment joint between the annular closure flange and a second end of the inner shell. The inner shell, first lid, and first end closure may collectively define a sealed primary pressure retention barrier. A tubular outer shell may adjoin the inner shell. The outer shell may be welded to the canister to form a hermetically sealed secondary pressure retention barrier.
A natural passively cooled ventilated cask includes a cavity which holds a canister containing heat and radiation emitting spent nuclear fuel assemblies or other high level wastes. Ambient ventilation or cooling air is drawn inwards beneath the cask and vertically upwards into a lower portion of the cavity through air inlet ducts formed integrally with a bottom canister support structure coupled to the cask. The air heated by the canister flows upwards in the cavity and returns to atmosphere through air outlet ducts in the cask lid. Air circulation is driven via natural convective thermo-siphon flow. Structural standoff members elevate the bottom of the cask above a concrete base pad forming an air inlet plenum beneath the canister support structure. The lateral sidewall surface of the cask has no penetrations for the air inlets, which eliminates any streaming path for radiation emanating from the spent nuclear fuel.
An underground ventilated system for storing nuclear waste materials. The system includes a storage module having an outer shell defining an internal cavity and an inner shell. A majority of the height of the outer shell may be disposed below grade. The outer shell may include a hermetically sealed bottom. First and second canisters are positioned in lower and upper portions within the cavity respectively in vertically stacked relationship. A centering and spacing ring assembly is interspersed between the first and second canisters to transfer the weight of the upper second canister to the lower first canister. The assembly may include centering lugs which laterally restrain the first and second canisters in case of a seismic event. A natural convection driven ventilated air system cools the canisters to remove residual decay heat to the atmosphere. In one non-limiting embodiment, the shells are made of steel.
An apparatus for supporting spent nuclear fuel including a plurality of wall plates arranged in an intersecting manner to define a basket apparatus extending along a longitudinal axis. The basket apparatus may include a plurality of fuel cells and a plurality of flux traps between adjacent fuel cells. A plurality of reinforcement members may be positioned in the flux traps and may extend between opposing ones of the wall plates that form the flux traps. Each of the wall plates may be a slotted wall plate. The slotted wall plates may be interlocked with one another to form the basket apparatus. Each of the slotted wall plates may include an upper edge, a lower edge, and a plurality of plate slots formed in each of the upper and lower edges. The plate slots of the slotted wall plates may receive intersecting slotted wall plates.
An impact amelioration system for nuclear fuel storage components in one embodiment includes a fuel storage canister and outer cask receiving the canister. The canister is configured for storing spent nuclear fuel or other high level radioactive waste. A plurality of impact limiter assemblies are disposed on the bottom closure plate of the cask at the canister interface. Each impact limiter assembly comprises an impact limiter plug frictionally engaged with a corresponding plug hole formed in the cask closure plate. The canister rests on tops of the plugs, which may protrude upwards beyond the top surface of the bottom closure lid. The plugs and holes may mating tapered and frictionally engaged surfaces. During a cask drop event, the canister drives the plugs deeper into the plug holes and elastoplastically deform to dissipate the kinetic impact energy and protect the structural integrity of the canister and its contents.
An impact amelioration system for nuclear fuel storage components in one embodiment includes a fuel storage canister and outer cask receiving the canister. The canister is configured for storing spent nuclear fuel or other high level radioactive waste. A plurality of impact limiter assemblies are disposed on the bottom closure plate of the cask at the canister interface. Each impact limiter assembly comprises an impact limiter plug frictionally engaged with a corresponding plug hole formed in the cask closure plate. The canister rests on tops of the plugs, which may protrude upwards beyond the top surface of the bottom closure lid. The plugs and holes may mating tapered and frictionally engaged surfaces. During a cask drop event, the canister drives the plugs deeper into the plug holes and elastoplastically deform to dissipate the kinetic impact energy and protect the structural integrity of the canister and its contents.
G21F 5/12 - Closures for containersSealing arrangements
42.
Nuclear waste cask with impact protection, impact amelioration system for nuclear fuel storage, unventilated cask for storing nuclear waste, and storage and transport cask for nuclear waste
A nuclear waste cask with impact protection includes impact limiters comprising deformable energy-absorbing perforated sleeves. An impact amelioration system for nuclear fuel storage components includes impact limiter assemblies at the bottom cask to canister interface including impact limiter plugs frictionally engaging corresponding plug holes formed in the cask closure plate. A nuclear waste fuel storage system includes an unventilated cask including a heavy free-floating radiation shielding lid loosely coupled the top end of the cask in a movable manner via the anchor bosses which provides cask over pressurization protection. A nuclear waste cask includes an axially elongated rectangular cuboid cask body having a cavity for holding nuclear waste materials and cask locking mechanism including first locking protrusions on the lid which are selectively interlockable with mating second locking protrusions on the cask body to lock the lid to the cask body.
A nuclear fuel storage system comprises a fuel rack immersible in a fuel pool which comprises a baseplate and a cellular body extending from the baseplate. The body comprises plural cell walls arranged to define an array of upwardly open cells each configured to store a nuclear fuel assembly therein. A raised fuel assembly support ring may be disposed at the bottom of each cell on the baseplate to engage and support a fuel assembly. A neutron absorber insert disposed in at least one cell comprises a bottom end configured to frictionally engage the support ring to secure the neutron absorber insert therein. The absorber insert comprises resiliently deformable radial locking protrusions which frictionally engage an outward facing annular side surface of the support ring in one embodiment. The absorber insert may be retrofit into existing racks to restore reactivity control.
G21C 19/32 - Apparatus for removing radioactive objects or materials from the reactor discharge area, e.g. to a storage placeApparatus for handling radioactive objects or materials within a storage place or removing them therefrom
A fuel rack for storing nuclear fuel in a fuel pool in one embodiment comprises a baseplate configured for placement in a fuel pool, and a cellular body coupled to the baseplate. The body comprises tightly-packed upwardly open cells which each hold a nuclear fuel assembly. In one embodiment, each cell may have a hexagonal cross-sectional configuration. The cells are each formed by angled cell walls and corners formed between adjoining cell walls. Adjacent cells are arranged to meet in corner-to-corner alignment. This produces triangular-shaped flux traps interspersed between the cells for reactivity control. In some embodiments, at least one peripheral side of the fuel rack has an undulating configuration defining a series of alternating peaks and valleys which nests with a complementary configured peripheral side of an adjacent fuel rack. This provides higher packing density of fuel racks and fuel assemblies in the fuel pool.
G21F 5/015 - Transportable or portable shielded containers for storing radioactive sources, e.g. source carriers for irradiation unitsRadioisotope containers
G21F 5/02 - Transportable or portable shielded containers with provision for restricted exposure of a radiation source within the container
A fuel rack for storing nuclear fuel in a fuel pool in one embodiment comprises a baseplate configured for placement in a fuel pool, and a cellular body coupled to the baseplate. The body comprises tightly-packed upwardly open cells which each hold a nuclear fuel assembly. In one embodiment, each cell may have a hexagonal cross-sectional configuration. The cells are each formed by angled cell walls and corners formed between adjoining cell walls. Adjacent cells are arranged to meet in corner-to-corner alignment. This produces triangular-shaped flux traps interspersed between the cells for reactivity control. In some embodiments, at least one peripheral side of the fuel rack has an undulating configuration defining a series of alternating peaks and valleys which nests with a complementary configured peripheral side of an adjacent fuel rack. This provides higher packing density of fuel racks and fuel assemblies in the fuel pool.
A neutron absorbing insert for use in a fuel rack. In one aspect, the insert includes: a plate structure having a first wall and a second wall that is non-coplanar to the first wall; the first and second walls being formed by a single panel of a metal matrix composite having neutron absorbing particulate reinforcement that is bent into the non-coplanar arrangement along a crease; and a plurality of spaced-apart holes formed into the single panel along the crease prior to bending.
F22B 1/16 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour
F22B 33/18 - Combinations of steam boilers with other apparatus
F22B 37/00 - Component parts or details of steam boilers
G21F 1/08 - MetalsAlloysCermets, i.e. sintered mixtures of ceramics and metals
47.
Radiation shielded enclosure for spent nuclear fuel cask
A containment enclosure for shielding an outer cask containing an inner canister loaded with nuclear waste such as spent fuel rods. The enclosure includes a lower base portion at least partially embedded in a concrete pad and an upper radiation shielding portion defined by a shield jacket coupled to and supported by the lower base portion at a circumferential joint. Cavities of the base and shielding portions collectively define a contiguous containment space for the cask. A portion of the cask resides in each of the base and shielding portions which completely enclose and shield the cask to minimize radiation dosage of personnel in the environment surrounding the cask. The cask is cooled by a natural convectively-driven ambient cooling air ventilation system including air inlets at the circumferential joint of the enclosure. The concrete pad may be part of a spent nuclear fuel storage installation comprising plural cask containment enclosures.
A fuel rack apparatus includes a base plate having an upper surface and a lower surface; and a plurality of rectangular storage tubes coupled to and extending upward from the upper surface of the base plate, the storage tubes arranged in a side-by-side arrangement to form an array of the storage tubes. Each storage tube extends vertically along a longitudinal axis and includes an outer tube defining an inner cavity, and a neutron-absorbing inner plate-assemblage positioned within the outer tube that divides the inner cavity into a plurality of interior flux trap chambers and a fuel storage cell. The inner plate assembly includes a pair of angled chevron plates comprising boron. The chevron plates are arranged to define a hexagonal-shaped fuel storage cell forming triangular-shaped interior flux trap spaces between the chevron plates and the outer tube.
A vertical bundle air-cooled heat exchanger, a finned tube assembly for an air cooled condenser and method for forming the same, and a system for removing thermal energy generated by radioactive materials. In one aspect, an air cooled condenser sized for industrial and commercial application includes an inlet steam distribution header for conveying steam, a condensate outlet header for conveying condensate, an array of tube bundles each having a plurality of finned tube assemblies having a bare steel tube with an exposed outer surface and a set of aluminum fins brazed directly onto the tube by a brazing filler metal. The steel tubes may be spaced apart by the aluminum fins and have an inlet end fluidly coupled to the inlet steam distribution header and an outlet end fluidly coupled to the outlet header. A forced draft fan may be arranged to blow air through the tube bundles.
B23P 15/26 - Making specific metal objects by operations not covered by a single other subclass or a group in this subclass heat exchangers
F28B 1/06 - Condensers in which the steam or vapour is separated from the cooling medium by walls, e.g. surface condenser using air or other gas as the cooling medium
F28B 9/10 - Auxiliary systems, arrangements, or devices for extracting, cooling, and removing non-condensable gases
F28D 1/02 - Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with the heat-exchange conduits immersed in the body of fluid
F28D 7/10 - Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged one within the other, e.g. concentrically
F28F 1/00 - Tubular elementsAssemblies of tubular elements
F28F 1/16 - Tubular elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally the means being integral with the element, e.g. formed by extrusion
F28F 1/20 - Tubular elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally the means being attachable to the element
A system uses nuclear fuel decay heat to heat a building. The system includes a plurality of fluidly-isolated but thermally-coupled heat removal flow loops that operate in tandem to absorb thermal energy originating from water in a spent nuclear fuel pool located in the building. The thermal energy is transferred in a cascading manner from a first flow loop to a final flow loop which has an external heat sink located outside the building. The heat sink can transfer heat to an ambient environment. A controller regulates the intake and flowrate of cooling water into the final flow loop. The controller also monitors fuel pool water temperature and air temperature inside the building. The controller can regulate the flowrate to maintain a predetermined building air temperature by allowing the fuel pool water temperature to rise to near a maximum permissible limit.
An underground ventilated system for storing nuclear waste materials. The system includes a storage module having an outer shell defining an internal cavity and an inner shell. A majority of the height of the outer shell may be disposed below grade. The outer shell may include a hermetically sealed bottom. First and second canisters are positioned in lower and upper portions within the cavity respectively in vertically stacked relationship. A centering and spacing ring assembly is interspersed between the first and second canisters to transfer the weight of the upper second canister to the lower first canister. The assembly may include centering lugs which laterally restrain the first and second canisters in case of a seismic event. A natural convection driven ventilated air system cools the canisters to remove residual decay heat to the atmosphere. In one non-limiting embodiment, the shells are made of steel.
A radioactive nuclear waste storage system includes a cask comprising a hermetically sealed internal cavity configured for holding the waste such as spent nuclear fuel submerged in an inventory of water. One or more pressure surge capacitors disposed inside the cask include a vacuum cavity evacuated to sub-atmospheric conditions prior to storage of fuel in the cask. At least one rupture disk seals a vacuum chamber inside each capacitor. Each rupture disk is designed and constructed to burst at a predetermined burst pressure level occurring inside the cask external to the capacitor. This allows excess cask pressure occurring during a high pressure excursion resulting from abnormal operating conditions to bleed into capacitor, thereby returning the pressure inside the cask to acceptable levels. In one embodiment, the capacitors are located in peripheral regions of the cask cavity adjacent to the circumferential wall of the cask body.
A thermal energy storage system includes one or more containment vessel comprising an internal cavity containing a bed of phase change material (PCM) operable to store thermal energy, an array of heaters embedded in the molten phase change material, and a tube bundle. The heaters are electrically coupled to an electric power source and operable to heat and melt the PCM to a molten state. The tube bundle comprises heat exchanger tubes embedded in the molten PCM and configured to convey a working fluid (e.g., water or other) through a tube-side of the tubes. The tubes may be arranged in plural individual tube cartridge each insertable and removable from the vessel. In operation, the working fluid is heated by absorbing stored thermal energy from the molten phase change material. The PCM may be heated by power extracted from the power grid during off-peak demand periods.
F28D 20/02 - Heat storage plants or apparatus in generalRegenerative heat-exchange apparatus not covered by groups or using latent heat
F22B 1/02 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
F24H 7/02 - Storage heaters, i.e. heaters in which the energy is stored as heat in masses for subsequent release the released heat being conveyed to a transfer fluid
F22G 1/00 - Steam superheating characterised by heating method
A natural passively cooled ventilated cask includes a cavity which holds a canister containing heat and radiation emitting spent nuclear fuel assemblies or other high level wastes. Ambient ventilation or cooling air is drawn inwards beneath the cask and vertically upwards into a lower portion of the cavity through air inlet ducts formed integrally with a bottom canister support structure coupled to the cask. The air heated by the canister flows upwards in the cavity and returns to atmosphere through air outlet ducts in the cask lid. Air circulation is driven via natural convective thermo-siphon flow. Structural standoff members elevate the bottom of the cask above a concrete base pad forming an air inlet plenum beneath the canister support structure. The lateral sidewall surface of the cask has no penetrations for the air inlets, which eliminates any streaming path for radiation emanating from the spent nuclear fuel.
A natural passively cooled ventilated cask includes a cavity which holds a canister containing heat and radiation emitting spent nuclear fuel assemblies or other high level wastes. Ambient ventilation or cooling air is drawn inwards beneath the cask and vertically upwards into a lower portion of the cavity through air inlet ducts formed integrally with a bottom canister support structure coupled to the cask. The air heated by the canister flows upwards in the cavity and returns to atmosphere through air outlet ducts in the cask lid. Air circulation is driven via natural convective thermo-siphon flow. Structural standoff members elevate the bottom of the cask above a concrete base pad forming an air inlet plenum beneath the canister support structure. The lateral sidewall surface of the cask has no penetrations for the air inlets, which eliminates any streaming path for radiation emanating from the spent nuclear fuel.
A passively cooled stackable nuclear waste storage system may include a pair of vertically stacked radiation-shielded nuclear waste storage casks. Each cask has a cavity which holds a nuclear waste canister containing spent nuclear fuel or other high-level radioactive wastes. The lower cask may be founded on an above-grade concrete pad. The upper cask is vertically stacked on and detachably coupled to the lower cask. The upper cask comprises a perforated baseplate which establishes fluid communication between cavities of both casks and is configured to prevent radiation shine. One or both casks may include air inlet vents configured to draw ambient ventilation air into each respective cask cavity for cooling the nuclear waste. In operation, air is drawn inward into each cask cavity independently. Air heated in the lower cask rises into the upper cask where it mixes with air drawn into the upper cask and is returned to atmosphere.
A thermal energy storage system includes one or more containment vessel comprising an internal cavity containing a bed of phase change material (PCM) operable to store thermal energy, an array of heaters embedded in the molten phase change material, and a tube bundle. The heaters are electrically coupled to an electric power source and operable to heat and melt the PCM to a molten state. The tube bundle comprises heat exchanger tubes embedded in the molten PCM and configured to convey a working fluid (e.g., water or other) through a tube-side of the tubes. The tubes may be arranged in plural individual tube cartridge each insertable and removable from the vessel. In operation, the working fluid is heated by absorbing stored thermal energy from the molten phase change material. The PCM may be heated by power extracted from the power grid during off-peak demand periods.
A passively cooled stackable nuclear waste storage system includes an at least partially below grade cavity enclosure container (CEC) and above grade cask. Each vessel includes a cavity holding a nuclear waste canister containing spent nuclear fuel or other high-level radioactive wastes. The CEC is founded on a below grade concrete base pad and cask is mounted on an above-grade concrete top pad in a vertically stacked arrangement. The upper cask comprises a perforated baseplate which establishes fluid communication between cavities of both casks and is configured to prevent radiation shine. One or both vessels include air inlets which draw ambient cooling air into their respective cavities for cooling the nuclear waste. Air heated in the lower CEC rises into the upper cask through the baseplate where it mixes with air drawn into the cask and is returned to atmosphere. The system increases storage capacity of new or existing facilities.
A nuclear waste cask in one embodiment includes an axially elongated cask body defining a longitudinally-extending opening forming an entrance to an internal storage cavity of the cask configured for holding radioactive nuclear waste materials. A closure lid detachably coupled to the cask body at the top opening seals the cavity. A cask locking mechanism includes a plurality of first locking protrusions spaced apart on the lid which are selectively interlockable with a plurality of second locking protrusions spaced apart on the cask body to lock the lid to the cask body. The first locking protrusions may be disposed on slideable locking bars moveable between locked and unlocked positions while the lid remains stationary on the cask body. Hydraulic or pneumatic actuators may be used to change position of the locking bars. The cask and lid may include other features such as impact absorbers and lifting elements.
A passively cooled stackable nuclear waste storage system may include a pair of vertically stacked radiation-shielded nuclear waste storage casks. Each cask has a cavity which holds a nuclear waste canister containing spent nuclear fuel or other high-level radioactive wastes. The lower cask may be founded on an above-grade concrete pad. The upper cask is vertically stacked on and detachably coupled to the lower cask. The upper cask comprises a perforated baseplate which establishes fluid communication between cavities of both casks and is configured to prevent radiation shine. One or both casks may include air inlet vents configured to draw ambient ventilation air into each respective cask cavity for cooling the nuclear waste. In operation, air is drawn inward into each cask cavity independently. Air heated in the lower cask rises into the upper cask where it mixes with air drawn into the upper cask and is returned to atmosphere.
A container system for radioactive waste and method for using the same is provided. The system includes a canister configured for holding radioactive waste and a lid system. In one embodiment, the lid system comprises a two-part lid assembly including a confinement lid and a shielded lifting lid. The confinement lid is detachably mounted to the confinement lid. In use, the lifting lid supports the confinement lid for lifting and placement on the canister. The lifting lid further shields operators while the confinement lid is mounted to the canister. Thereafter, the lifting lid is removed and may be reused for confinement lid mountings on other canisters. In one embodiment, the confinement lid is bolted to the canister. The canister may be disposed in a protective overpack for transport and storage.
An automatically adjusting seismic restraint system for nuclear fuel storage in one embodiment comprises a free-standing first fuel storage component (FSC) configured to contain nuclear fuel, and a stationary second FSC configured to receive the first fuel storage component. An inter-body gap formed between the FSCs includes at least one seismic restraint assembly. The assembly includes a stationary wedge member fixedly coupled to the second FSC and a movable loose wedge member engaged with and supported in place by the stationary wedge member. The stationary wedge member defines an inclined load bearing surface slideably engaged with a mating inclined load bearing surface of the loose wedge member. During a seismic event or thermal expansion of the first FSC, the first FSC moves towards the second FSC which shrinks the inter-body gap and the loose wedge member is vertically displaced relative to the stationary wedge member while maintaining engagement therewith.
A nuclear fuel decay heat utilization system usable for space heating in one embodiment comprises a nuclear generation plant building housing a spent fuel pool containing submerged fuel assemblies which emit decay heat that heats the pool. Plural fluidly isolated but thermally coupled heat removal systems comprising pumped flow loops operate in tandem to absorb thermal energy from the heated pool water, and transfer the thermal energy through the systems in a cascading manner form one to the next to a final external heat sink outside the plant building from which the heat is rejected to the ambient environment. A programmable controller operably regulates the intake and flowrate of water from the heat sink into the heat removal systems and monitors ambient air temperature inside to building. The flowrate is regulated to maintain a preprogrammed building setpoint air temperature by increasing fuel pool water temperature to a maximum permissible limit.
G21C 15/243 - Promoting flow of the coolant for liquids
G21C 19/00 - Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
F28D 7/00 - Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
64.
Automatically adjusting seismic restraint system for nuclear fuel storage
An automatically adjusting seismic restraint system for nuclear fuel storage in one embodiment comprises a free-standing first fuel storage component (FSC) configured to contain nuclear fuel, and a stationary second FSC configured to receive the first fuel storage component. An inter-body gap formed between the FSCs includes at least one seismic restraint assembly. The assembly includes a stationary wedge member fixedly coupled to the second FSC and a movable loose wedge member engaged with and supported in place by the stationary wedge member. The stationary wedge member defines an inclined load bearing surface slideably engaged with a mating inclined load bearing surface of the loose wedge member. During a seismic event or thermal expansion of the first FSC, the first FSC moves towards the second FSC which shrinks the inter-body gap and the loose wedge member is vertically displaced relative to the stationary wedge member while maintaining engagement therewith.
A passively cooled stackable nuclear waste storage system includes an at least partially below grade cavity enclosure container (CEC) and above grade cask. Each vessel includes a cavity holding a nuclear waste canister containing spent nuclear fuel or other high-level radioactive wastes. The CEC is founded on a below grade concrete base pad and cask is mounted on an above-grade concrete top pad in a vertically stacked arrangement. The upper cask comprises a perforated baseplate which establishes fluid communication between cavities of both casks and is configured to prevent radiation shine. One or both vessels include air inlets which draw ambient cooling air into their respective cavities for cooling the nuclear waste. Air heated in the lower CEC rises into the upper cask through the baseplate where it mixes with air drawn into the cask and is returned to atmosphere. The system increases storage capacity of new or existing facilities.
A fuel rack comprises a base plate and vertically-extending hexagonal tubes. Each tube defines a cell. A top surface of the base plate forms a floor of each cell. Adjustable height pedestals can be connected to a bottom surface of the base plate. Each pedestal includes a tool engagement portion in a top surface of a peg. Rotation of the peg causes pedestal height adjustment. Each peg is aligned with a hole in a cell floor. A tool can extend through the hole to adjust the height of the pedestal. Vertically elongated spacing rods are positioned in gaps between adjacent hexagonal tubes to maintain the gaps. Each spacing rod is plug welded to a corner edge of three adjacent hexagonal tubes at a juncture via holes located in the corner edges of each of the three adjacent hexagonal tubes.
An underground passively ventilated nuclear waste storage system includes an array of cavity enclosure containers each including a cavity holding a nuclear waste canister containing radioactive waste generating heat. Each container comprises at least one pair of air inlets each fluidly coupled directly to separate vertical cooling air feeder shells spaced apart from the container. The feeder shell in fluid communication with ambient air operates to draw in ventilation air which flows to the container via natural convective thermo-siphon effect driven by heat emitted from the canister which heats the container cavity. The containers are arranged in a serial spaced apart manner in multiple parallel rows. The containers within each row are fluidly isolated from containers in other rows. Containers within each row are further fluidly isolated from other containers therein when the ventilation system operates. The containers may be part of a consolidated interim storage facility for radioactive waste.
A nuclear fuel storage system includes an outer canister and fuel basket positioned therein. The basket is formed by orthogonally arranged and interlocked slotted plates which collectively define exterior side surfaces of the basket and a grid array of open cells each configured to hold a fuel assembly. At least some slotted plates comprise cantilevered plate extensions protruding laterally beyond the side surfaces of the basket to define various shaped peripheral gaps between the basket and canister. The plate extensions are configured to engage the shell of the canister. Vertically elongated reinforcement members are inserted in the peripheral gaps and fixedly coupled to the basket. Reinforcement members may comprise elongated reinforcement plates and/or tubular shimming members which may be fixedly coupled to the slotted plate extensions. The reinforcement members structurally strengthen the fuel basket. The plate extensions further act as fins to enhance heat dissipation from the basket.
G21F 5/015 - Transportable or portable shielded containers for storing radioactive sources, e.g. source carriers for irradiation unitsRadioisotope containers
G21F 5/06 - Details of, or accessories to, the containers
A spent nuclear fuel storage facility. In one embodiment, the invention is directed to a storage facility including an array of storage containers. Each of the storage containers includes a body portion and a lid. The body portion has a storage cavity configured to hold a canister containing spent nuclear fuel. The lid, which may rest atop the body portion in a detachable manner, includes an inlet vent and an outlet vent. Each of the storage containers may be configured to draw air through the inlet vent and into the storage cavity where the air is warmed and passed through the outlet vent as heated air. The body portion of the storage containers may be positioned below grade and the lid of the storage containers may be positioned above grade.
Manufacturing methods for fabricating nuclear waste canisters used to store spent nuclear fuel assemblies are disclosed to mitigate stress corrosion cracking. The method may generally comprise providing one or more stainless steel sheets used to form a shell of the canister. The shell comprises open butt joints which are welded closed via full shell thickness type welds of preferably narrow profile. The welds and adjoining heat affect zone may then be subjected to mechanical through-thickness compaction, which converts a residual tensile stress field in the shell base material adjoining the weld to a compressive stress field for a full thickness of the shell. The crown of the external exposed portion of the weld is flattened by the compaction and may be coplanar with the exterior surface of the shell. Surface peening may optionally be performed on the welded zone after compaction.
A natural passively cooled ventilated cask includes a cavity which holds a canister containing heat and radiation emitting spent nuclear fuel assemblies. Cooling air inlet ducts draw ambient cooling air inwards into a lower portion of the cavity. The air heated by the canister flows upwards along the canister and is discharged from at least one air outlet duct formed by the cask lid to atmosphere via natural convective thermo-siphon flow. The air inlet ducts or at least one outlet duct in one embodiment may be fitted with an adjustable shutter plate which allows the flowrate of air entering the cask to be increased or decreased to maintain a predetermined canister maximum temperature limit selected in part to prevent the onset of stress corrosion cracking of the canister welds. Other embodiments may use a fixed orifice plate replaceable over time to maintain the minimum temperature.
A natural passively cooled ventilated cask includes a cavity which holds a canister containing heat and radiation emitting spent nuclear fuel assemblies. Cooling air inlet ducts draw ambient cooling air inwards into a lower portion of the cavity. The air heated by the canister flows upwards along the canister and is discharged from at least one air outlet duct formed by the cask lid to atmosphere via natural convective thermo-siphon flow. The air inlet ducts or at least one outlet duct in one embodiment may be fitted with an adjustable shutter plate which allows the flowrate of air entering the cask to be increased or decreased to maintain a predetermined canister maximum temperature limit selected in part to prevent the onset of stress corrosion cracking of the canister welds. Other embodiments may use a fixed orifice plate replaceable over time to maintain the minimum temperature.
Nuclear waste cask with impact protection, impact amelioration system for nuclear fuel storage, unventilated cask for storing nuclear waste, and storage and transport cask for nuclear waste
A nuclear waste cask with impact protection includes impact limiters comprising deformable energy-absorbing perforated sleeves. An impact amelioration system for nuclear fuel storage components includes impact limiter assemblies at the bottom cask to canister interface including impact limiter plugs frictionally engaging corresponding plug holes formed in the cask closure plate. A nuclear waste fuel storage system includes an unventilated cask including a heavy free-floating radiation shielding lid loosely coupled the top end of the cask in a movable manner via the anchor bosses which provides cask overpressurization protection. A nuclear waste cask includes an axially elongated rectangular cuboid cask body having a cavity for holding nuclear waste materials and cask locking mechanism including first locking protrusions on the lid which are selectively interlockable with mating second locking protrusions on the cask body to lock the lid to the cask body.
A radioactive nuclear waste storage system includes a cask comprising a hermetically sealed internal cavity configured for holding the waste such as spent nuclear fuel submerged in an inventory of water. One or more pressure surge capacitors disposed inside the cask include a vacuum cavity evacuated to sub-atmospheric conditions prior to storage of fuel in the cask. At least one rupture disk seals a vacuum chamber inside each capacitor. Each rupture disk is designed and constructed to burst at a predetermined burst pressure level occurring inside the cask external to the capacitor. This allows excess cask pressure occurring during a high pressure excursion resulting from abnormal operating conditions to bleed into capacitor, thereby returning the pressure inside the cask to acceptable levels. In one embodiment, the capacitors are located in peripheral regions of the cask cavity adjacent to the circumferential wall of the cask body.
An underground ventilated system for storing nuclear waste materials. The system includes a storage module having an outer shell defining an internal cavity and an inner shell. A majority of the height of the outer shell may be disposed below grade. The outer shell may include a hermetically sealed bottom. First and second canisters are positioned in lower and upper portions within the cavity respectively in vertically stacked relationship. A centering and spacing ring assembly is interspersed between the first and second canisters to transfer the weight of the upper second canister to the lower first canister. The assembly may include centering lugs which laterally restrain the first and second canisters in case of a seismic event. A natural convection driven ventilated air system cools the canisters to remove residual decay heat to the atmosphere. In one non-limiting embodiment, the shells are made of steel.
A radioactive nuclear waste storage system includes a cask comprising a hermetically sealed internal cavity configured for holding the waste such as spent nuclear fuel submerged in an inventory of water. One or more pressure surge capacitors disposed inside the cask include a vacuum cavity evacuated to sub-atmospheric conditions prior to storage of fuel in the cask. At least one rupture disk seals a vacuum chamber inside each capacitor. Each rupture disk is designed and constructed to burst at a predetermined burst pressure level occurring inside the cask external to the capacitor. This allows excess cask pressure occurring during a high pressure excursion resulting from abnormal operating conditions to bleed into capacitor, thereby returning the pressure inside the cask to acceptable levels. In one embodiment, the capacitors are located in peripheral regions of the cask cavity adjacent to the circumferential wall of the cask body.
G21C 19/00 - Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
An induced draft air-cooled condenser for steam condensing applications includes a pair of inclined tube bundles defining a interior space therebetween in fluid communication with ambient air heated as it flows through the tube bundles. A fan supported above the interior space comprises rotatable fan blades disposed inside a cylindrical annular fan shroud. A drive mechanism operable to rotate the fan blades includes a motor operably coupled to the fan blades. The motor is supported inside the fan shroud and may be housed in a protective enclosure which may be insulated. A motor cooling system includes an air inlet duct fluidly coupled to ambient air outside the shroud and the enclosure. When the fan operates, cool ambient air is drawn via a vacuum formed by the fan through the duct to cool the motor. The air thus bypasses and is not heated by the tube bundles.
B01D 5/00 - Condensation of vapoursRecovering volatile solvents by condensation
F28B 1/06 - Condensers in which the steam or vapour is separated from the cooling medium by walls, e.g. surface condenser using air or other gas as the cooling medium
F28B 1/02 - Condensers in which the steam or vapour is separated from the cooling medium by walls, e.g. surface condenser using water or other liquid as the cooling medium
78.
Passive cooling device for casks containing nuclear fuel
A system for externally cooling a cask containing heat-emitting spent nuclear fuel includes the cask comprising a radiation shielding body defining an internal cavity configured to hold a canister containing the spent nuclear fuel. A continuously annular cooling jacket extends circumferentially around an external surface of the cask body. The cooling jacket may have a double shell construction including an internal cavity for a cooling medium which provides an external heat sink for absorbing heat radiated from the external wall surface of the cask generated by the spent nuclear fuel. The heat emitted by the spent nuclear fuel is absorbed by the cooling medium in the cooling jacket, thereby in turn cooling the cask. In one embodiment, the cooling medium may be dry ice which undergoes sublimation by absorbing the heat to change from solid to gaseous phase directly. The jacket may be formed of multiple segments.
An induced draft air-cooled condenser for steam condensing applications includes a pair of inclined tube bundles defining a interior space therebetween in fluid communication with ambient air heated as it flows through the tube bundles. A fan supported above the interior space comprises rotatable fan blades disposed inside a cylindrical annular fan shroud. A drive mechanism operable to rotate the fan blades includes a motor operably coupled to the fan blades. The motor is supported inside the fan shroud and may be housed in a protective enclosure which may be insulated. A motor cooling system includes an air inlet duct fluidly coupled to ambient air outside the shroud and the enclosure. When the fan operates, cool ambient air is drawn via a vacuum formed by the fan through the duct to cool the motor. The air thus bypasses and is not heated by the tube bundles.
F28B 1/06 - Condensers in which the steam or vapour is separated from the cooling medium by walls, e.g. surface condenser using air or other gas as the cooling medium
80.
Nuclear fuel storage system with integral shimming
A nuclear fuel storage system includes an outer canister and fuel basket positioned therein. The basket is formed by orthogonally arranged and interlocked slotted plates which collectively define exterior side surfaces of the basket and a grid array of open cells each configured to hold a fuel assembly. At least some slotted plates comprise cantilevered plate extensions protruding laterally beyond the side surfaces of the basket to define various shaped peripheral gaps between the basket and canister. The plate extensions are configured to engage the shell of the canister. Vertically elongated reinforcement members are inserted in the peripheral gaps and fixedly coupled to the basket. Reinforcement members may comprise elongated reinforcement plates and/or tubular shimming members which may be fixedly coupled to the slotted plate extensions. The reinforcement members structurally strengthen the fuel basket. The plate extensions further act as fins to enhance heat dissipation from the basket.
G21F 5/00 - Transportable or portable shielded containers
G21F 5/06 - Details of, or accessories to, the containers
G21F 5/015 - Transportable or portable shielded containers for storing radioactive sources, e.g. source carriers for irradiation unitsRadioisotope containers
A nuclear waste cask in one embodiment includes an axially elongated cask body defining a longitudinally-extending opening forming an entrance to an internal storage cavity of the cask configured for holding radioactive nuclear waste materials. A closure lid detachably coupled to the cask body at the top opening seals the cavity. A cask locking mechanism includes a plurality of first locking protrusions spaced apart on the lid which are selectively interlockable with a plurality of second locking protrusions spaced apart on the cask body to lock the lid to the cask body. The first locking protrusions may be disposed on slideable locking bars moveable between locked and unlocked positions while the lid remains stationary on the cask body. Hydraulic or pneumatic actuators may be used to change position of the locking bars. The cask and lid may include other features such as impact absorbers and lifting elements.
A nuclear waste cask in one embodiment includes an axially elongated cask body defining a longitudinally-extending opening forming an entrance to an internal storage cavity of the cask configured for holding radioactive nuclear waste materials. A closure lid detachably coupled to the cask body at the top opening seals the cavity. A cask locking mechanism includes a plurality of first locking protrusions spaced apart on the lid which are selectively interlockable with a plurality of second locking protrusions spaced apart on the cask body to lock the lid to the cask body. The first locking protrusions may be disposed on slideable locking bars moveable between locked and unlocked positions while the lid remains stationary on the cask body. Hydraulic or pneumatic actuators may be used to change position of the locking bars. The cask and lid may include other features such as impact absorbers and lifting elements.
G21F 5/00 - Transportable or portable shielded containers
B65D 25/26 - Devices for protecting contents against shock
F16J 13/08 - Detachable closure membersMeans for tightening closures attached by one or more members actuated to project behind a part or parts of the frame
G21F 5/005 - Containers for solid radioactive wastes, e.g. for ultimate disposal
A nuclear waste fuel storage system includes an unventilated cask including inner and outer shells, an annular space between the shells containing radiation shielding, and sealed baseplate. Threaded anchor bosses are affixed to the top end of the cask. A heavy free-floating radiation shielding lid is loosely coupled the top end of the cask in a movable manner via the anchor bosses by bolt assemblies which loosely secure the lid to the cask. An internal cavity of the cask which holds a nuclear waste fuel canister is sealed by an annular gasket compressed between the lid and cask, thereby forming a gas tight pressure vessel operable to retain internal pressures exceeding atmospheric. During a cask overpressurization condition, the lid automatically moves between a normal downward sealed position on the cask to an installer-adjustable raised relief position ajar from the cask to relieve excess pressure to atmosphere.
A nuclear waste fuel storage system includes an unventilated cask including inner and outer shells, an annular space between the shells containing radiation shielding, and sealed baseplate. Threaded anchor bosses are affixed to the top end of the cask. A heavy free-floating radiation shielding lid is loosely coupled the top end of the cask in a movable manner via the anchor bosses by bolt assemblies which loosely secure the lid to the cask. An internal cavity of the cask which holds a nuclear waste fuel canister is sealed by an annular gasket compressed between the lid and cask, thereby forming a hermetically sealed gas tight pressure vessel operable to retain internal pressures exceeding atmospheric. During a cask overpressurization condition, the lid automatically moves between a normal downward sealed position on the cask to an installer- adjustable raised relief position ajar from the cask to relieve excess pressure to atmosphere.
G21C 19/32 - Apparatus for removing radioactive objects or materials from the reactor discharge area, e.g. to a storage placeApparatus for handling radioactive objects or materials within a storage place or removing them therefrom
G21C 19/40 - Arrangements for preventing occurrence of critical conditions, e.g. during storage
G21F 5/12 - Closures for containersSealing arrangements
A neutron absorbing insert for use in a fuel rack. In one aspect, the insert includes: a plate structure having a first wall and a second wall that is non-coplanar to the first wall; the first and second walls being formed by a single panel of a metal matrix composite having neutron absorbing particulate reinforcement that is bent into the non-coplanar arrangement along a crease; and a plurality of spaced-apart holes formed into the single panel along the crease prior to bending.
F01K 25/08 - Plants or engines characterised by use of special working fluids, not otherwise provided forPlants operating in closed cycles and not otherwise provided for using special vapours
G21F 1/08 - MetalsAlloysCermets, i.e. sintered mixtures of ceramics and metals
F22B 1/16 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour
F22B 37/00 - Component parts or details of steam boilers
F22B 33/18 - Combinations of steam boilers with other apparatus
86.
Impact amelioration system for nuclear fuel storage
An impact amelioration system for nuclear fuel storage components in one embodiment includes a fuel storage canister and outer cask receiving the canister. The canister is configured for storing spent nuclear fuel or other high level radioactive waste. A plurality of impact limiter assemblies are disposed on the bottom closure plate of the cask at the canister interface. Each impact limiter assembly comprises an impact limiter plug frictionally engaged with a corresponding plug hole formed in the cask closure plate. The canister rests on tops of the plugs, which may protrude upwards beyond the top surface of the bottom closure lid. The plugs and holes may mating tapered and frictionally engaged surfaces. During a cask drop event, the canister drives the plugs deeper into the plug holes and elastoplastically deform to dissipate the kinetic impact energy and protect the structural integrity of the canister and its contents.
A module for storing high level radioactive waste includes an outer shell, having a hermetically closed bottom end, and an inner shell forming a cavity and being positioned inside the outer shell to form a space therebetween. At least one divider extends from the top to the bottom of the inner shell to create a plurality of inlet passageways through the space, each inlet passageway connecting to a bottom portion of the cavity. A plurality of inlet ducts each connect at least one of the inlet passageways and ambient atmosphere, and each includes an inlet duct cover affixed atop a surrounding inlet wall, the inlet wall being peripherally perforated. A removable lid is positioned atop the inner shell and has at least one outlet passageway connecting the cavity and the ambient atmosphere, the lid and the top of the inner shell being configured to form a hermetic seal therebetween.
A system for preparing a container holding radioactive waste for dry storage. In one aspect, the invention can be a system for preparing a container having a cavity loaded with radioactive elements for dry storage, the system comprising: a gas circulation system comprising a condenser module, a desiccant module, and a gas circulator module; the gas circulation system configured to form a hermetically sealed closed-loop path when operably connected to the cavity of the container; and means for adding and removing the desiccant module as part of the hermetically sealed closed-loop path.
G21F 5/06 - Details of, or accessories to, the containers
F26B 5/04 - Drying solid materials or objects by processes not involving the application of heat by evaporation or sublimation of moisture under reduced pressure, e.g. in a vacuum
F26B 21/14 - Arrangements for supplying or controlling air or gases for drying solid materials or objects using gases or vapours other than air or steam
G21C 19/32 - Apparatus for removing radioactive objects or materials from the reactor discharge area, e.g. to a storage placeApparatus for handling radioactive objects or materials within a storage place or removing them therefrom
G21F 5/005 - Containers for solid radioactive wastes, e.g. for ultimate disposal
A dry storage systems for radioactive nuclear waste materials may include a double-walled canister system. The canister system may include a canister having a tubular inner shell defining an internal cavity for storing nuclear waste material, a first lid sealably welded to a first end of the inner shell, a primary base plate defining a peripheral edge portion and having an annular closure flange, and an annular full thickness butt weld formed at an abutment joint between the annular closure flange and a second end of the inner shell. The inner shell, first lid, and first end closure may collectively define a sealed primary pressure retention barrier. A tubular outer shell may adjoin the inner shell. The outer shell may be welded to the canister to form a hermetically sealed secondary pressure retention barrier.
An air-cooled condenser system for steam condensing applications in a power plant Rankine cycle includes an air cooled condenser having a plurality of interconnected modular cooling cells. Each cell comprises a frame-supported fan, inlet steam headers, outlet condensate headers, and tube bundle assemblies having extending between the headers. The tube bundle assemblies may be arranged in a V-shaped tube structure. A plurality of deflection limiter beams are arranged coplanar with the tube bundles. Top ends of each deflection limiter beam are slideably inserted in an associated floating end cap affixed to an upper tubesheet which moves vertically relative to the beams via thermal expansion/contraction concomitantly with the tubes. The deflection limiter beams provides guided restraint system for expansion/contraction of the tube bundles which prevents out of plane tube bowing.
F28B 1/06 - Condensers in which the steam or vapour is separated from the cooling medium by walls, e.g. surface condenser using air or other gas as the cooling medium
G21F 5/12 - Closures for containersSealing arrangements
A method of forming a sealed canister and a method of storing radioactive materials is provided. The method of forming includes placing a top plate on a top opening of a side wall, a bottom of the side wall being sealed to a base plate. The top plate includes a top surface with a top edge having a bevel and with a channel set in from the top edge. Finally, a weld is formed between the beveled top edge and the top opening of the side wall to seal the top plate to the side wall.
An impact amelioration system for nuclear fuel storage components in one embodiment includes a fuel storage canister and outer cask receiving the canister. The canister is configured for storing spent nuclear fuel or other high level radioactive waste. A plurality of impact limiter assemblies are disposed on the bottom closure plate of the cask at the canister interface. Each impact limiter assembly comprises an impact limiter plug frictionally engaged with a corresponding plug hole formed in the cask closure plate. The canister rests on tops of the plugs, which may protrude upwards beyond the top surface of the bottom closure lid. The plugs and holes may mating tapered and frictionally engaged surfaces. During a cask drop event, the canister drives the plugs deeper into the plug holes and elastoplastically deform to dissipate the kinetic impact energy and protect the structural integrity of the canister and its contents.
A nuclear fuel storage system includes an outer canister and fuel basket positioned therein. The basket is formed by orthogonally arranged and interlocked slotted plates which collectively define exterior side surfaces of the basket and a grid array of open cells each configured to hold a fuel assembly. At least some slotted plates comprise cantilevered plate extensions protruding laterally beyond the side surfaces of the basket to define various shaped peripheral gaps between the basket and canister. The plate extensions are configured to engage the shell of the canister. Vertically elongated reinforcement members are inserted in the peripheral gaps and fixedly coupled to the basket. Reinforcement members may comprise elongated reinforcement plates and/or tubular shimming members which may be fixedly coupled to the slotted plate extensions. The reinforcement members structurally strengthen the fuel basket. The plate extensions further act as fins to enhance heat dissipation from the basket.
A nuclear waste cask with impact protection includes impact limiters detachably coupled to opposite ends of the cask. Each impact limiter may comprise a deformable energy-absorbing perforated sleeve of cylindrical shape comprising an array of closely-spaced longitudinally elongated perforations. The perforations may comprise longitudinal passages having a circular cross-sectional shape in certain embodiments. The perforated sleeve may have an annular metallic body of monolithic unitary structure in which the perforations are formed and a central opening to receive the ends of the cask therein. When exposed to external impact forces such as created by dropping the cask, the perforations collapse inwards in the impact or crush zone to absorb the energy of fall while preventing or minimizing any forces transmitted to the cask to maintain the integrity of waste containment barrier.
A nuclear waste cask with impact protection includes impact limiters detachably coupled to opposite ends of the cask. Each impact limiter may comprise a deformable energy-absorbing perforated sleeve of cylindrical shape comprising an array of closely-spaced longitudinally elongated perforations. The perforations may comprise longitudinal passages having a circular cross-sectional shape in certain embodiments. The perforated sleeve may have an annular metallic body of monolithic unitary structure in which the perforations are formed and a central opening to receive the ends of the cask therein. When exposed to external impact forces such as created by dropping the cask, the perforations collapse inwards in the impact or crush zone to absorb the energy of fall while preventing or minimizing any forces transmitted to the cask to maintain the integrity of waste containment barrier.
A neutron absorbing insert for use in a fuel rack. In one aspect, the insert includes: a plate structure having a first wall and a second wall that is non-coplanar to the first wall; the first and second walls being formed by a single panel of a metal matrix composite having neutron absorbing particulate reinforcement that is bent into the non-coplanar arrangement along a crease; and a plurality of spaced-apart holes formed into the single panel along the crease prior to bending.
A method of retrofitting a spent nuclear fuel system with a neutron absorbing apparatus. The method includes inserting a neutron absorbing apparatus into a first cell of an array of cells each configured to hold a spent nuclear fuel assembly. The neutron absorbing apparatus includes a first wall and a second wall supported by a corner spine to form a chevron shape and a first locking tab protruding outwardly from the first wall towards a first cell wall of the first cell. The method includes cutting a half-sheared second locking tab in the first cell wall of the first cell adjacent to and above the first locking tab of the neutron absorbing apparatus. Finally, the second locking tab is positioned to locking engage the first locking tab to retain the neutron absorbing apparatus in the first cell during removal of one of the fuel assemblies from the first cell.
A containment enclosure for shielding an outer cask containing an inner canister loaded with nuclear waste such as spent fuel rods. The enclosure includes a lower base portion at least partially embedded in a concrete pad and an upper radiation shielding portion defined by a shield jacket coupled to and supported by the lower base portion at a circumferential joint. Cavities of the base and shielding portions collectively define a contiguous containment space for the cask. A portion of the cask resides in each of the base and shielding portions which completely enclose and shield the cask to minimize radiation dosage of personnel in the environment surrounding the cask. The cask is cooled by a natural convectively-driven ambient cooling air ventilation system including air inlets at the circumferential joint of the enclosure. The concrete pad may be part of a spent nuclear fuel storage installation comprising plural cask containment enclosures.
G21F 5/005 - Containers for solid radioactive wastes, e.g. for ultimate disposal
G21C 19/00 - Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
G21F 1/00 - Shielding characterised by the composition of the material
A containment enclosure for shielding an outer cask containing an inner canister loaded with nuclear waste such as spent fuel rods. The enclosure includes a lower base portion at least partially embedded in a concrete pad and an upper radiation shielding portion defined by a shield jacket coupled to and supported by the lower base portion at a circumferential joint. Cavities of the base and shielding portions collectively define a contiguous containment space for the cask. A portion of the cask resides in each of the base and shielding portions which completely enclose and shield the cask to minimize radiation dosage of personnel in the environment surrounding the cask. The cask is cooled by a natural convectively-driven ambient cooling air ventilation system including air inlets at the circumferential joint of the enclosure. The concrete pad may be part of a spent nuclear fuel storage installation comprising plural cask containment enclosures.
An apparatus for supporting spent nuclear fuel including a plurality of wall plates arranged in an intersecting manner to define a basket apparatus extending along a longitudinal axis. The basket apparatus may include a plurality of fuel cells and a plurality of flux traps between adjacent fuel cells. A plurality of reinforcement members may be positioned in the flux traps and may extend between opposing ones of the wall plates that form the flux traps. Each of the wall plates may be a slotted wall plate. The slotted wall plates may be interlocked with one another to form the basket apparatus. Each of the slotted wall plates may include an upper edge, a lower edge, and a plurality of plate slots formed in each of the upper and lower edges. The plate slots of the slotted wall plates may receive intersecting slotted wall plates.
