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 modular dry spent fuel canister system in which several different types of inner spent nuclear fuel canisters can be loaded into the same outer cask family. This family typically includes a storage overpack, a transfer cask, a transportation cask and support or auxiliary hardware. The various canisters can be loaded interchangeably into the different types of outer casks. The inner canisters are differentiated not by physical fuel type or dimension, but by the engineering objective or criterion that applies to the spent fuel being stored. One such objective may be for a single canister to store a large number of assemblies economically and safely. A second is a canister designed to greatly reduce the cooling time (or radioactive decay time) that must pass in order to load spent nuclear fuel for off-site storage, so as to meet the decay heat requirements and capabilities of the off-site storage system.

A modular dry spent fuel canister system in which several different types of inner spent nuclear fuel canisters can be loaded into the same outer cask family. This family typically includes a storage overpack, a transfer cask, a transportation cask and support or auxiliary hardware. The various canisters can be loaded interchangeably into the different types of outer casks. The inner canisters are differentiated not by physical fuel type or dimension, but by the engineering objective or criterion that applies to the spent fuel being stored. One such objective may be for a single canister to store a large number of assemblies economically and safely. A second is a canister designed to greatly reduce the cooling time (or radioactive decay time) that must pass in order to load spent nuclear fuel for off-site storage, so as to meet the decay heat requirements and capabilities of the off-site storage system.

A storage apparatus with radiation shielding for spent nuclear fuel includes a fuel basket comprising elongated fuel storage tubes each defining an open cell configured to hold a nuclear fuel assembly. Gamma radiation attenuation inserts are nested inside at least some of the storage tubes. The inserts each comprise elongated open-ended tubular bodies which may have a rectangular cuboid configuration with square cross section. The inserts are composed of a dense metallic material selected for blocking gamma radiation and may have high thermal conductivity for effective heat dissipation from the decaying nuclear fuel. Attenuation inserts can occupy some or all perimeter tubes to provide shielding against gamma radiation emanating in a lateral direction from the fuel basket. The inserts may include upper and lower securement features for detachable fixation to the storage tubes, and air/gas flow cutouts.

A storage apparatus with radiation shielding for spent nuclear fuel includes a fuel basket comprising elongated fuel storage tubes each defining an open cell configured to hold a nuclear fuel assembly. Gamma radiation attenuation inserts are nested inside at least some of the storage tubes. The inserts each comprise elongated open-ended tubular bodies which may have a rectangular cuboid configuration with square cross section. The inserts are composed of a dense metallic material selected for blocking gamma radiation and may have high thermal conductivity for effective heat dissipation from the decaying nuclear fuel. Attenuation inserts can occupy some or all perimeter tubes to provide shielding against gamma radiation emanating in a lateral direction from the fuel basket. The inserts may include upper and lower securement features for detachable fixation to the storage tubes, and air/gas flow cutouts.

A canister for storing spent nuclear fuel includes an elongated shell, baseplate enclosing the bottom end of the shell, and removable top lid bolted to the shell. The shell may have a dual thickness comprising a lower portion with first thickness and upper portion with greater second thickness by comparison. The upper portion is formed by an annular boss defining a fastening portion of the shell including plural threaded bores for engaging the lid bolting. The fastening portion may protrude radially outwards or inwards in different embodiments. The lid has a mounting flange receiving the bolts and is seated on the top end of shell. The mounting flange does not protrude radially beyond the outer surface of the fastener portion to minimize the diameter of the canister for placement inside an outer radiation shielded overpack or cask for transport/storage. The shell may optionally include cooling fins.

A canister for storing spent nuclear fuel includes an elongated shell, baseplate enclosing the bottom end of the shell, and removable top lid bolted to the shell. The shell may have a dual thickness comprising a lower portion with first thickness and upper portion with greater second thickness by comparison. The upper portion is formed by an annular boss defining a fastening portion of the shell including plural threaded bores for engaging the lid bolting. The fastening portion may protrude radially outwards or inwards in different embodiments. The lid has a mounting flange receiving the bolts and is seated on the top end of shell. The mounting flange does not protrude radially beyond the outer surface of the fastener portion to minimize the diameter of the canister for placement inside an outer radiation shielded overpack or cask for transport/storage. The shell may optionally include cooling fins.

A container is designed to safely store radioactive debris. The container has an overpack having an elongated body extending between a top end and a bottom end. A basket is situated inside of the overpack. The basket has elongated canisters. Each of the canisters has an elongated body extending between a top end and a bottom end. At least one of the canisters has an insert with a plurality of elongated perforated tubes that contain radioactive debris. The perforations enable gas flow, primarily air, through the side wall to enable evaporation of liquid, primarily water, from the radioactive debris, by increasing the exposed surface area of the debris.

A container is designed to safely store radioactive debris. The container has an overpack having an elongated body extending between a top end and a bottom end. A basket is situated inside of the overpack. The basket has elongated canisters. Each of the canisters has an elongated body extending between a top end and a bottom end. At least one of the canisters has an insert with a plurality of elongated perforated tubes that contain radioactive debris. The perforations enable gas flow, primarily air, through the side wall to enable evaporation of liquid, primarily water, from the radioactive debris, by increasing the exposed surface area of the debris.

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.