Spent fuel cooling system back up at Fukushima No. 3 reactor

TOKYO — One of the systems keeping spent nuclear fuel cool at the Fukushima nuclear plant temporarily failed on Friday, the second outage in a matter of weeks, underlining the precarious fix at the plant.

Tokyo Electric Power (TEPCO) said an alarm sounded at the facility at 2:27 p.m., and technicians soon confirmed that the cooling system for the pool attached to the No. 3 reactor was not working.

Nuclear fuel, even after use, has to be kept cool to prevent it from overheating and beginning a self-sustaining atomic reaction that could lead to meltdown.

The problem, which was fixed in about three hours, occurred as work crew placed a metal mesh around a switchboard in a bid to prevent small animals from touching it, a TEPCO spokesman told a press conference.

The TEPCO spokesman said a wire or the mesh might have touched the ground while crews put the mesh in place, unintentionally grounding the equipment and knocking it offline.

TEPCO apologized for the problem, but stressed that it had not posed any immediate danger.
[link to www.japantoday.com]
.