Thursday, June 28, 2012

Problem after Problem after Problem at Ooi Nuke Plant, Still Set to Restart on July 1

(UPDATE) "... after Problem" Alarms sounded off in the central control room for the Reactor 3's pump in the afternoon of June 29, according to Jiji Tsushin (6/29/2012). The pump circulates the primary coolant that goes into the Reactor 3 Pressure Vessel.

Today's protest in front of the PM's Official Residence is shaping up to be big, people are tweeting.


I have a feeling that KEPCO may be worse than TEPCO when it comes to cost cutting and deferred maintenance. After all, Kansai merchants are historically known for shrewd, economizing ways to make more profit.

In a matter of few days, Ooi Nuclear Power Plant has managed to have three separate minor problems, and two of them triggered alarms. First it was poor maintenance, then it was a human error, then probably another case of poor maintenance.

First, about aging rubber seal that caused the short circuit, from Sankei Shinbun local Fukui version(6/29/2012):

大飯原発3号機一時漏電 雨水浸入が原因

Temporary short circuit at Reactor 3 at Ooi Nuclear Power Plant, caused by rainwater leaking in


KEPCO announced on June 28 that a temporary short circuit at the switching station for Reactor 3 at Ooi Nuclear Power Plant (in Ooi-cho) was caused by the rainwater leaking into the equipment that control the power supply system at the station.


According to KEPCO, after checking the 108 parts that control the system, the company found one of the parts filled with water. KEPCO thinks the rubber seal had deteriorated, allowing the rainwater to leak in. The company says it will take countermeasures such as replacing the rubber seal.

Then, an alarm went off in the central control room at the power panel for Reactor 3, as KEPCO reported on June 28.

From KEPCO's press release on June 28, 2012:


About the alarm "Attention C DC power panel failure" sounding off at Reactor 3 at Ooi Nuclear Power Plant(announcement)

大飯発電所3号機(加圧水型軽水炉 定格電気出力118万キロワット、定格熱出力342万3千キロワット)は、再稼動に向けた作業中の平成24年6月28日15時58分に、中央制御室の3号機所内盤において、「C直流電源盤故障注意」警報が発信しました。

Reactor 3 at Ooi Nuclear Power Plant is currently prepared for the restart. At 3:58PM on June 28, 2012, an alarm "Attention C DC power panel failure" sounded off at the panel for Reactor 3 in the central control room.


The alarm was reset at 4:05PM.


The alarm was set off when our operator accidentally turned off the power switch when he tried to turn on the monitor screen.


There is no failure of the equipment.


This incident is within the safety regulations and it is not a trouble as defined by laws and regulations. It has nothing to do with the work currently undertaken for the restart of the reactor, and there will be no effect on the work.


Also, there is no radiation leak in the environment.

That's what the government regulations do. As long as it is within the government-mandated laws and regulations, it is not a problem as far as the laws and regulations are concerned. No one will be at fault.

"Pro forma" was mentioned by the reader Atomfritz on another post about Ooi Nuke Plant mishap. Right on the money.

But wait, there's more. Another alarm was set off on June 29, this time at Reactor 4.

From Jiji Tsushin (6/29/2012):


NISA: An alarm at Reactor 4 at Ooi Nuke Plant, possible failure at the pump that samples coolant


Nuclear and Industrial Safety Agency under the Ministry of Economy, Trade and Industry announced on June 29 that an alarm was set off at the pump at the steam condenser. The pump is used to sample coolant to make sure no seawater is mixed in. NISA and KEPCO will disassemble the pump and investigate.


According to NISA, the alarm was sounded before 10AM on June 29. The alarm is set off when there is a large excess pressure in the pump. There is a possibility that the sampled water didn't flow smoothly or was blocked.


gary minesmall said...

People can hardly drive let alone...

Janick in Tokyo said...

frightening....... Thanks for the detailed info.

Atomfritz said...

Indeed, frightening.
Kepco guys seem to be of the reLAXed sort.

Rainwater leak k.o.-ing the reactor power supply due to relaxed maintenance. Amazing.

Amazing too, how the guy managed to turn off one of the DC buses.
Placing and protective-capping of important switches, an old practice in the industry (at least outside of Japan) should prevent such potentially catastrophic human errors.
Or the operator was under influence or otherwise mentally absent?

Maybe Kepco's company motto is:
Oops! Don't be angry, nobody is perfect!

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