#Fukushima I Nuke Plant: Photo of an Electrocuted and Very Dead Mouse

Remember that power outage? TEPCO released the result of their investigation on March 25, 2013.

The mouse has a mark in the stomach from an electric shock.

From TEPCO's Photos and Videos Library, 3/25/2013, "Progress of Investigation of Power Supply Facilities Failure at Fukushima Daiichi Nuclear Power Station":

The regular M/C was receiving power from the temporary M/C because of the ongoing renovation work:

(Text part)

[Power supply system structure]
Since power receiving cable renovation for the regular M/C in the Process Building (as part of Tsunami countermeasures) was ongoing at the time of the incident, the regular M/C was temporarily receiving power from the
backup M/C in the Process Building.
[Analysis]
1. The ground relay in B system operated: The failure is assumed to have occurred in B system and high voltage power supply system.
2. The circuit breakers of the regular M/C (3A) and (4A) in the Process Building and the backup M/C in the Process
Building (3A) tripped due to overcurrent. : The failure is assumed to have occurred in the downstream of the regular M/C in the Process Building (4A).
3. The ground directional relays and the circuit breakers of Units 3-4 temporary M/C (4A), (5A) and (10A) did not
operate. : The failure is assumed to hav
e occurred in the upstreamof the load systems of Units 3-4 temporary M/C.
4. Fault current was found in Units 3-4 temporary M/C (A)(5B). : The failure is assumed to have occurred in the
downstream of Units 3-4 temporary M/C (A) (5B).

Conclusion page:

TEPCO will install mouse traps as countermeasure.

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#Fukushima I Nuke Plant Power Failure Aftermath: A Small Animal (Rat?) Found in the Temporary Switchboard

No further information such as:

• What the animal was;

• Whether the animal was singed or burned;

• How the animal died; or

• Whether the wiring had been damaged (by the animal).

What we do know is the animal is about 15 centimeters long, or 25 centimeters including the tail.

Asahi's "Hodo Station" news apparently made a decision on its own that the animal was burned to death, and reported as such. But from the TEPCO's afternoon press conference on March 20, 2013, there was no reference to how the animal, which does look like a rat, died.

From TEPCO's Photos and Videos on March 20, 2013:

3/4 M/C (A) Switchboard box on what looks like a trailer bed:

Workers inspecting 3/4 M/C (A):

The bottom compartment looks fine:

But above,　the terminals look burned:

And the compartment wall is sooty:

And here's the animal, at the bottom of the compartment (photo taken from above):

From my personal experience, there is no way to prevent rodents from entering any enclosure and build nests. You have to be very vigilant and monitor regularly, and remove the first bits of nesting materials or shit as soon as you see them. If this switchboard enclosure has been there on the the trailer since March 18, 2011 without regular inspection, I would be surprised if there were no rat's nest.

"TEPCO" stands for Tokyo Electric Power Company. It should know very well how these critters behave.

On second thoughts, such knowledge was probably held by TEPCO's subcontractors, not by TEPCO.

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Power Restored at #Fukushima I Nuke Plant, TEPCO Still Don't Know What Went Wrong

TEPCO still doesn't know what caused the power failure and how, therefore does not have measures in place to prevent any future power failure. Pressure from the national government was clearly on the operator to just start cooling and not worry about minor details like what caused the failure.

Ad hoc has been the name of the game for the past two years. Why change now?

Asahi Shinbun (3/20/2013; part):

今回の停電は、東日本大震災での事故以降では最大規模。だが原因は特定できていない。東電によると、停電の発端とみられる不具合が起きた３、４号機につながる仮設の配電盤は、目で見て分かる異常は確認できなかったという。当初は原因を突き止め、対策を講じた上で復旧させる予定だったが、復旧を優先させることにし、仮設配電盤を通さずに、別の配電盤に冷却装置を接続することで電源を確保した。

The power outage this time was the most severe since the start of the accident. However, the cause of the outage hasn't been identified. According to TEPCO, there was no visible sign of abnormality in the temporary switchboard that is connected to Reactors 3 and 4, where a trouble that led to the power outage was thought to have started. The company had initially planned to identify the cause, install measures to prevent future problems, and then turn the power back on. However, restoring the power was given the priority, and the cooling systems were connected to a different switchboard, circumventing the temporary switchboard.

The particular temporary switchboard is "3/4 M/C (A)" (M/C stands for "metal clad"). The location (or connection) of the switchboard in the overall electrical system looks different in the two different diagrams below. Either way, I don't quite understand why Reactor 1 should be affected by the failure of this switchboard, as the Reactor 1 cooling system does not appear to be connected to this switchboard.

As TEPCO's spokesman Ono explained it (via Ryuichi Kino),

所内共通Ｍ／Ｃ」（２Ａ）と（２Ｂ）にも波及

[The trouble at "3/4/ M/C (A)"] had the ripple effect on Plant-wide common M/C (2A)(2B)

(I don't have a clue as to how that could happen.)

3/4 M/C (A) (in blue circle that I added), in the diagram provided by TEPCO in the press conference on March 19, 2013, via Ryuichi Kino:

3/4 M/C (A), in the diagram from March 2012, from then-Nuclear and Industrial Safety Agency (NISA, also from Ryuichi Kino:

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#Fukushima I Nuke Plant: Power Back On, Cooling of Reactor 1 SFP Resumed

(UPDATE-2) Common Spent Fuel Pool cooling is scheduled to resume at 8AM on March 20.

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(UPDATE) Jiji Tsushin reports that TEPCO hopes to resume cooling of the SFPs of Reactor 3 and Reactor 4 at about 8PM (Japan Time). (It's about 3:45PM in Japan now.)

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Information from NHK Kabun (Science and Literature) tweet, about 20 minutes ago:

１９日午後２時２０分頃、福島第一原発の電源復旧。１号機燃料プールの冷却再開

At about 2:20PM on March 19, power was back on at Fukushima I Nuclear Power Plant. Cooling of Reactor 1 Spent Fuel Pool resumed.

No information about other Spent Fuel Pools or other facilities. No details as to what caused the power failure to begin with.

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Chief Cabinet Minister's Word on #Fukushima I Nuke Plant's Power Outage: "There Is No Worry, In a Way"

Totally incomprehensible remark from Chief Cabinet Secretary Yoshihide Suga during the morning press conference on March 19, 2013.

As Jiji Tsushin reports (3/19/2013):

菅義偉官房長官は１９日午前の記者会見で、同原発の停電について「冷却のための代替手段に万全の対応をする予定なので、ある意味で全く心配ない」と述べた。

Chief Cabinet Secretary Yoshihide Suga said during the press conference in the morning of March 19 about the power outage at Fukushima I Nuke Plant, "Since we are going to thoroughly prepare for the alternative methods of cooling, there is absolutely no worry, in a way."

Here I thought the redundant methods of cooling, not to mention the redundant power supplies, had long been installed at the plant. Maybe Mr. Suga meant the alternative methods of cooling by the new LDP administration under Mr. Abe.

What he means by "in a way" is totally lost on me.

Power is not back on yet, and the TEPCO spokesman says they haven't identified the location of the problem though they are narrowing down. The temperature of Reactor 4's SFP is 30 degrees Celsius, up 5 degrees since the power outage. The spokesman seems to be regurgitating what he was told to say without understanding any of it, and it is evident by the way he tries to answer questions from the reporters.

Needless to say, Chief Cabinet Secretary doesn't seem to have a clue of what he's saying, either.

And as usual, there are people on Twitter spreading wild information like "They've been doing the vent! It's dangerous!" and people retweeting anxiously.

I guess nobody has a clue.

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#Fukushima I Nuke Plant Cannot Cool Spent Fuel Pools, Cause Unknown

(UPDATE-4) As of 2:20PM on March 19, 2013, cooling of Reactor 1's Spent Fuel Pool resumed. No information about other SFPs and facilities affected by the power outage.

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(UPDATE-3) The temperature of Reactor 4's SFP is 30 degrees Celsius, up 5 degrees since the power outage.

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(UPDATE-2) More than 15 hours after the power outage (Japan Time 10:30AM on March 19), there is still no power. TEPCO is having a press conference right now. The new spokesman who croaks is not very good at explaining things in a straight-forward way. (My guess is that he doesn't know well what he is talking about, unlike his predecessor Matsumoto.)

In June 2012, cooling of the Reactor 4 SFP stopped for about 30 hours when the pump of the secondary cooling system burned out.

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(UPDATE) Jiji Tsushin says the water temperature of Reactor 4's Spent Fuel Pool (the "hottest") is about 25 degrees Celsius. The safety standard for the SFP temperature is 65 degrees Celsius, and it is estimated it will take about 4 days without power to reach that temperature. In the Reactor 4 SFP, both used and new fuel assemblies are under 7 meters (23 feet) of water. Fuel assemblies are 4-meter (13 feet) long. According to the plant operator (announcement from May 2012, in Japanese only), it takes about 3 weeks for the water 5 meter deep (i.e. still leaving 2 meters of water above the fuel assemblies) to evaporate.

The common pool has old fuel assemblies whose decay heat is already very low.

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It took three hours for TEPCO to announce the power outage at Fukushima I Nuclear Power Plant. (Same old, same old...)

From Kyodo News (3/19/2013):

福島第１原発で停電　使用済み燃料プール冷却が停止

Power outage at Fukushima I Nuke Plant, cooling of spent fuel pools stopped

東京電力は１８日、福島第１原発で午後７時前に停電があったと発表した。１、３、４号機の使用済み燃料プール代替冷却システムなどが停止し、１９日午前０時２５分時点で復旧のめどは立っていない。事故対応に当たっている免震重要棟も一時的に停電したが、すぐに復旧した。

TEPCO announced on March 18 that there was a power outage at Fukushima I Nuclear Power Plant slightly before 7PM. Cooling systems for the spent fuel pools in Reactors 1, 3, 4 has stopped, and as of 12:25AM on March 19 there is no knowing when the systems will be back. Power went out also in Anti-Seismic Building temporarily but it came back on quickly.

原子力規制庁によると、１～３号機の原子炉への注水に問題は生じていない。燃料６３７７体を保管する共用プールの冷却も停止した。

According to the Nuclear Regulatory Agency, there is no problem in injecting water into the reactors. Cooling of the common spent fuel pool, which contains 6,377 fuel assemblies, has also stopped.

東電は「配電盤か、接続されたケーブルが原因の可能性がある」としているが、規制庁、東電とも原因を特定できていない。東電が停電を公表したのは、発生約３時間後の午後１０時すぎだった。

According to TEPCO, the problem could be either the switchboard or the cables connected to the switchboard. Both the Nuclear Regulatory Agency and TEPCO have been unable to identify the cause. TEPCO announced the power outage after 10PM, three hours after it had taken place.

The plant receives its electricity from Tohoku Electric Power Company. There is no problem receiving this external power.

(H/T reader Beppe)

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