Quelques explications (un peu) plus détaillées sur la panne.
TEPCO spokesman Yoshikazu Nagai said workers were still trying to determine the cause of the cooling failure, which began when a brief power blackout hit the plant Tuesday evening.
About 50 workers in hazmat suits and full-face masks were mobilized to fix the cabling to three switchboards that were suspected of involvement in the problem. TEPCO also prepared a backup system in case the repairs didn’t fix the issue and “worse comes to worst,” company spokesman Masayuki Ono said earlier Tuesday.
Ono acknowledged the plant was vulnerable.
“Fukushima Dai-ichi still runs on makeshift equipment, and we are trying to switch to something more permanent and dependable, which is more desirable,” he said. “Considering the equipment situation, we may be pushing a little too hard.”
Ono said the utility did not immediately try to switch to a backup cooling system because doing so without finding and fixing the cause could lead to a repeat of the problem.
There is a backup cooling system but no backup outside power source. TEPCO has backup cooling systems with separate power sources for reactor cooling, but fuel storage pools only have emergency diesel generators as a backup. TEPCO said it will consider installing backup outside power for the pools.
The Unit 3 and 4 reactors share a makeshift switchboard that sits on the back of a truck, but an upgrade to a permanent, safer location is being planned later this month. Reactor cooling water pumps also sit on the back of a truck, with hoses traveling several kilometers (miles) to reach the reactors.
Équipement de fortune, tableau de branchement au cul du camion, pompes du circuit de refroidissement au cul d’un camion à plusieurs kilomètres du site…
Mais on envisage d’améliorer tout ça et de mettre en place des circuits de secours moins bricolés.