Yet another welding related fire-now in a nuclear plant!

As if we did not have enough of welding related fire accidents in conventional plants (read my last post on the issue here ), now we have a report of a similar accident in a Japanese nuclear plant.

Here is the incident reported by various agencies:

A fire broke out at a nuclear power plant in northern Japan on Thursday, injuring one worker but causing no radiation leak, the operator said.

Firefighters put out the fire about an hour after white smoke was spotted coming out of the reactor, which was already shut for a regular check-up, Tohoku Electric Power said.

“One worker sustained minor burns but was not exposed to radiation,” a company spokesman said, adding there was no leak to the outside environment either. The fire started at around 2:00 p.m. at the plant’s No. 1 reactor, which has been undergoing regular checkups since February, Tohoku Electric said.

Kyodo News Agency which first reported the incident said the worker was in a welding operation inside the building, and the filter in the air conditioning system might have caught sparks from the welding.

The plant is located in Onagawa town, some 350 kilometres (220 miles) north of Tokyo. The plant has two other reactors, which are operating normally.

The nuclear power complex, which suffered extensive damage in an earthquake last year, has been out of service and undergoing repairs.

The incident occurred just days after a Dec. 1-5 inspection by a team from the United Nations nuclear watchdog. The team of 10 experts from the Vienna-based International Atomic Energy Agency assessed safety measures designed to deal with the continuing threat of earthquakes.

I hope the investigation is completely impartial and gives us some better ideas to prevent such incidents in future. I know that the nuclear industry is a highly regulated and procedure-driven industry so this incident is shocking. Secondly, this is the second such fire in a Japanese plant (the earlier one was supposed to be because of an earthquake). However as usual, the investigation reports are pretty sketchy and certainly not as detailed as the ones from the chemical /hydrocarbon processing industry (Well, if they are I have not seen many in the public domain). I wonder what kind of combustibles are present in such installations and what kind of gas detection systems are used. Anybody from the nuclear industry who is reading this could be kind enough to throw some more light on this issue.

Comments as usual are welcome.