Why cold-shutdown reactors still need a watch

Why would a reserve ship need a reactor crew if its reactor were in cold shutdown?

Cold shutdown does not remove the need for monitoring and daily inspection, though the watch can be smaller than an operational crew.

Even a cold-shutdown reactor remains under supervision. Stored British submarines provide the example: their reactors are watched and inspected daily. The personnel requirement is smaller than on an operational ship. That continuing watch is justified by the need to identify a developing fault before its consequences become serious.