A method for detecting gas leakage from a radioactive material sealed container includes measuring a temperature at a bottom portion of a metallic sealed container. A feeding air temperature of external air passing between the metallic sealed container and a concrete-made storage container is also measured. Presence of leakage of inactive gas is determined by comparing the temperatures or by utilizing a physical amount calculated by using the temperatures.

A method and apparatus for online condition monitoring of a spent nuclear fuel dry cask storage system. The method comprises monitoring physical parameters of air flowing through inlet vents and outlet vents of a system and observing successive measurements of the parameter for deviations from the baseline to determine if the condition of the system has changed. The parameters may include temperature, pressure, density, mass and volumetric flow rate, nuclear radiation, impurities, humidity, salt content, acidity, chemistry, and fission product gases. The information may then be used directly or to develop an accumulation profile. The data may also be used in modeling or other simulations and to establish condition change signatures. The apparatus includes sensors placed over inlet and outlet vents, sensor interfacing hardware connected to the sensors, and a computer connected to the hardware to acquire, display, and analyze the sensor data and to display the status of the system.

A method for detecting gas leakage from a radioactive material sealed container includes measuring a temperature at a bottom portion of a metallic sealed container. A feeding air temperature of external air passing between the metallic sealed container and a concrete-made storage container is also measured. Presence of leakage of inactive gas is determined by comparing the temperatures or by utilizing a physical amount calculated by using the temperatures.

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.