Level 1 incident at TEPCO's Kashiwazaki-Kariwa nuclear plant confirmed

[Emily]

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201212130030

Bent rod found at TEPCO's Niigata reactor
December 13, 2012
THE ASAHI SHIMBUN

Tokyo Electric Power Co. said Dec. 12 a bent water rod caused two fuel rods to come into contact inside a fuel rod assembly stored in a spent fuel storage pool for the No. 5 reactor of the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture.

No damage to nuclear fuel or other anomalies have been reported, but the two fuel rods may have been in contact with each other when they were burning inside the reactor.

The situation had the potential to cause a serious fuel failure accident...

http://english.kyodonews.jp/news/2012/12/200353.html

18:51 19 December
Regulators confirm level 1 incident at Kashiwazaki-Kariwa plant

TOKYO, Dec. 19, Kyodo

Japan's nuclear regulatory authority said Wednesday that recently confirmed trouble with fuel rods stored in a spent nuclear fuel pool at Tokyo Electric Power Co.'s Kashiwazaki-Kariwa plant is a level 1 incident on a 7-point international scale.

A pair of fuel rods was touching as a result of deformation in the bundle of fuel rods, leading the Nuclear Regulation Authority to determine that the fuel had likely been loaded to the reactor core "in an abnormal situation." The NRA's assessment of the incident is provisional.

According to the NRA, the flow of the coolant water through the bundle of fuel rods could be hampered if rods stick together, making it easier for heat to accumulate. The authority, however, said no leakage of radioactive substances was observed...