The invention relates to covers or closures for containers such as nuclear fuel storage canisters of the type used to store consolidations of spent fuel rods underwater. An understanding of fuel consolidation may be gained from U.S. Pat. No. 4,619,808 issued to Formanek, Oct. 28, 1986 and assigned to Combustion Engineering, Inc., assignee of the instant application.
It is important to know that stored spent nuclear fuel rods are in closed canisters which are fully identified as to content and time in residence in a spent fuel pool. To ensure the accuracy of records, indicia are stamped on the canister closure. It is also important to know that the closure has not been tampered with or that access to the contents has not been had to ensure such accuracy. Moreover, it is also important that the closure be inexpensive and capable of providing natural convection flow of the spent fuel pool liquid (water) therethrough. As a practical matter, it is also important that the closure not obstruct canister lift features for remote handling of the canister in the pool and that the tamper-proof closure can be easily positioned in place in the opening of the canister and removed when desired.
Nuclear fuel consolidation canisters are normally provided with a combination lifting and storage cover. These prior art covers are complicated and expensive and one is required for each canister. In using the instant invention, reusable separate lifting covers are employed in handling, but a new and expensive separate lifting cover for each canister is not required, since for storage, only the disposable sheet steel tamper-proof cover of the invention is needed.