Method for long-term dry storage of spent nuclear fuel includes injecting the inert gas into a cavity formed in a cask between inner and outer lids under pressure greater than the pressure of the inert gas in the inner cavity of the cask in which the spent nuclear fuel is located. The cask contains a body with a spent nuclear fuel container placed in it, tight inner and outer lids forming a cavity into which the inert gas is pumped under pressure greater than the pressure in the inner cavity of the cask. The outer lid comprises a labyrinth hole closed with a flange and sealed with a gasket. The flange comprises an angle valve, to which at least two pressure sensors are connected. The angle valve and sensors are covered with a protective cover during long-term storage. The gasket is installed in an annular groove of the lower flange.

A canister for storing radioactive materials includes a base plate, side wall and a top 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. The top plate is sealed to the sidewall by a weld formed between the beveled top edge and the top of the side wall. The base plate is sealed to a bottom of the sidewall, so that a sealed vessel is formed.

In a canister horizontally installed and housed inside a concrete silo, at least two temperatures out of a temperature T.sub.B at a canister bottom portion to be one end portion in a lateral direction in a horizontally-installed attitude, a temperature T.sub.SB at a canister side surface lower portion located below a horizontal plane passing through a center of the canister, a temperature T.sub.T at a canister lid portion to be the other end portion in the lateral direction, and a temperature T.sub.ST at a canister side surface upper portion located above the horizontal plane passing through the center of the canister are monitored, and occurrence of leakage of an inert gas inside the canister is detected when there is a change in a temperature difference between the at least two temperatures.

Techniques for inspecting a weld of a nuclear waste canister include positioning a gamma ray image detector near a nuclear waste canister that encloses nuclear waste. The nuclear waste canister includes a housing that includes a volume in which the waste is enclosed and a top connected to the housing with at least one weld to seal the nuclear waste in the nuclear waste canister. The techniques further include receiving, at the gamma ray image detector, gamma rays from the nuclear waste that travel through one or more voids in the weld; generating an image of the received gamma rays with the gamma ray image detector; and based on the generated image, determining an integrity of the at least one weld.

Disclosed is a lid (10) for closing a receptacle (20), the lid comprising: a static portion (18) arranged to substantially match an opening of the receptacle to be closed; a plurality of pivoting arms (11) coupled to the static portion; means (12) for moving the plurality of pivoting arms between a first position wherein the plurality of pivoting arms lie within a perimeter of the static portion and a second position wherein the plurality of pivoting arms lie outside a perimeter of the static portion and engage with a complementary feature of the receptacle.

Techniques for inspecting a weld of a nuclear waste canister include positioning a gamma ray image detector near a nuclear waste canister that encloses nuclear waste. The nuclear waste canister includes a housing that includes a volume in which the waste is enclosed and a top connected to the housing with at least one weld to seal the nuclear waste in the nuclear waste canister. The techniques further include receiving, at the gamma ray image detector, gamma rays from the nuclear waste that travel through one or more voids in the weld; generating an image of the received gamma rays with the gamma ray image detector; and based on the generated image, determining an integrity of the at least one weld.

Techniques for inspecting a weld of a nuclear waste canister include positioning a gamma ray image detector near a nuclear waste canister that encloses nuclear waste. The nuclear waste canister includes a housing that includes a volume in which the waste is enclosed and a top connected to the housing with at least one weld to seal the nuclear waste in the nuclear waste canister. The techniques further include receiving, at the gamma ray image detector, gamma rays from the nuclear waste that travel through one or more voids in the weld; generating an image of the received gamma rays with the gamma ray image detector; and based on the generated image, determining an integrity of the at least one weld.

A method for predicting corrosion rates of a material during service conditions is provided, the method having the steps of determining a first phase composition of the material; exposing the material to service conditions chemical environment; applying an electrical potential to the exposed material to represent the solution redox; identifying ranges of the applied potential that correspond to different corrosion behaviors of the material; quantifying current and surface electrical properties during corrosion; and determining a second phase composition of the material to identify corroded phases. Also provided is a method for determining radionuclide source terms, the method having the steps of supplying a multiphase metallic waste containing the radionuclides; immersing the waste in a solution representing repository chemistry conditions; and oxidizing the immersed waste for a period of time and at particular imposed voltages representing solution redox values to establish a steady current representing corrosion rate of the waste.

Method for long-term dry storage of spent nuclear fuel includes injecting the inert gas into a cavity formed in a cask between inner and outer lids under pressure greater than the pressure of the inert gas in the inner cavity of the cask in which the spent nuclear fuel is located. The cask contains a body with a spent nuclear fuel container placed in it, tight inner and outer lids forming a cavity into which the inert gas is pumped under pressure greater than the pressure in the inner cavity of the cask. The outer lid comprises a labyrinth hole closed with a flange and sealed with a gasket. The flange comprises an angle valve, to which at least two pressure sensors are connected. The angle valve and sensors are covered with a protective cover during long-term storage. The gasket is installed in an annular groove of the lower flange.

Apparatuses and methods for securely storing radioactive source materials that enables inventory activities with security functions. In particular, apparatuses and methods for securely storing radioactive source materials are provided with visual and automated inventory, security, alerting, and stabilization design elements that enable various inventory tasks, prevent storage structures from being negligently left open or unlocked, ensure stabilization of storage structures in a moving mobile structure, and provide an alerting system for warning staff of an unsecure or unlocked condition of such storage structures.