SFP 4 loss of cooling at F. Daiichi

A brief loss of power to a cooling system caused a brief cessation of spent fuel pool #4 work. Excavation work outside unit #4 caused damage to a power cable; cutting off supply to the SFP’s cooling system at 10:19am on Tuesday. By procedure, spent fuel transfer activities were stopped until cooling was restored. Power was resumed and cooling restarted at 2:16pm. Fuel transfer operations were resumed at 2:36pm. The Press reported that Tepco said the pool temperature could increase as much as 0.3^oC per hour, but actual readings showed barely a 0.1^oC rise over the four hour period.

http://www.tepco.co.jp/en/press/corp-com/release/2014/1234483_5892.html