Cooling air amount adjustment device of concrete cask and concrete cask

A cooling air amount adjustment device of a concrete cask, configured to:

• naturally convect external air as cooling air from an air inlet port provided at a lower portion of a concrete container to an air outlet port provided at an upper portion thereof;
• and store and simultaneously cool a canister sealing spent nuclear fuel, the device comprising
• at least one air outlet port opening level adjustment mechanism or at least one air inlet port opening level adjustment mechanism, which is configured to automatically perform:
• adjustment to reduce a flow rate of the cooling air when a temperature of the cooling air at the air outlet port is lower than an adjustment reference temperature, and
• adjustment to increase the flow rate of the cooling air so as to restore the flow rate of the cooling air when the temperature of the cooling air at the air outlet port is higher than the adjustment reference temperature,
• wherein the at least one air outlet port opening level adjustment mechanism or the at least one air inlet port opening level adjustment mechanism comprises:
• a rotary shaft connected to the air inlet port or to the air outlet port;
• and
• a bimetal portion forming a spiral fixed to the rotary shaft, wherein the spiral is configured to unwind in response to a change in temperature causing the rotary shaft to rotate to reduce the flow rate of the cooling air.