UPDATED 7:06 AM EST, December 19, 2012
Southern California Edison said in its October proposal to restart the Unit 2 reactor that the redesigned system, which relies on sensitive monitors to detect unusual vibrations, could help operators learn if any parts broke loose in the huge generators.
An NRC staff memo dated Dec. 10 said Edison wanted to upgrade the system, in part, to help detect a possible break in a tube that carries radioactive water. Each generator contains nearly 10,000 alloy tubes that carry heated water from the reactor.
