March 12th, 2011 – Chairman of Japan Atomic Energy Commission’s high-level report on Fukushima Daiichi sequence of events

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Dr. Shunsuke Kondo has been the Chairman of the Japan Atomic Energy Commission since January 2004.

Shunsuke Kondo was born on July 26, 1942. He obtained a bachelor’s degree from the Department of Nuclear Engineering, School of Engineering, The University of Tokyo in 1965 and became a Doctor of Engineering in Nuclear Engineering of The University of Tokyo in 1970.

Dr. Kondo became the Lecturer, in 1970, then an Associate Professor in 1971 at the Department of Nuclear Engineering, The University of Tokyo. After that, he became a Professor at Nuclear Engineering Research Laboratory, The University of Tokyo in 1984. He moved to the Department of Nuclear Engineering, The University of Tokyo in 1988 and remained there until his retirement in 2004.

The Department name was changed to Quantum Engineering and Systems Science in 1995. In addition, he was appointed to the Director, Research Institute for Nuclear Science and Technology, The University of Tokyo from 1999-2003.

After he retired from the The University of Tokyo, he became the Chairman, Japan Atomic Energy Commission in 2004.

From: [email protected] [mailto:[email protected]]
Sent: Saturday, March 12, 2011 7:07 AM
To: Bari, Robert A (b)(6)
Cc: Horak, William C; Braverman, Joseph I; Hofmayer, Charles H; Sheron, Brian
Subject: RE: Earthquake Impact

Dear Bob

Thank you very much for your kind email. We are still in the midst of the fight for cooling down the core of the plants, experiencing after shock almost every hour since the main shock yesterday.

Enclosed please find my personal note on the current situation at the site, just for your information.

Shunsuke Kondo

Current ( 15:30 of 2011/03/12) Situation of Fukushima Daiichi (1F, six units) and Fukushima Daini (2F, four units) Nuclear Power Plants Hit by Touhoku-chiho Taiheiyou-oki Earthquake (TT-EQ) on March 11, 2011

The TT-EQ caused automatic shutdown of all operating units of 1F, i.e. unit 1, 2, 3 and 2F, i.e. unit1, 2, 3, 4.

Simultaneously, the off-site powers to these units were lost due to the damage of many fossil and some of hydro power generating stations in the network with which these units’were connected. Furthermore, most of the emergency diesel generators (EDGs) of these units could not continue operation due to lack of cooling caused by extraordinary high Tsunami. In essence these units were put into the situation called “total blackout”.

The regulatory authority recommended every operator to prepare so-called (severe) accident management procedure and features that should be followed in such situation ten years ago and currently all operators have this procedure as a part of operation manual. Therefore TEPCO team has started the operation to cool the core based on this procedure.

The team was faced with difficulty in the execution, however, as the vital power source was not available also due to the flooding of the building: this power source is important as it is to supply power to sustain I&C system that is used to monitor plant status and operate motor-operated valve (MOV) necessary in this operation Therefore TEPCO gathered power supply trucks, DC batteries and fire-fighting engines from available sources near-by and the team started their fight to minimize the probability of occurrence of large-scale release, utilizing them.

IF Unit 1; Although RCIC is available to remove heat from the core, the reactor water level has decreased gradually to the level below the top of active core possibly due to some leakage from RPV boundary (containment pressure is now almost equal to RPV pressure) and the radiation level around the unit started to rose gradually at around 4:00 AM today.

The team has started the water injection using fire-fighting car or fire engines to stabilize core condition and challenged to open the valves in the fscrubbing venting line under high radiation condition. As Iodine and Cesium are recognized in the environment in parallel, though quite minor, the government asked evacuation to the people within 10 km from the plant as a precaution. We were very lucky that the wind direction was from land to sea at this time.

The team has succeeded to open the valves in the venting line at around 14:00 and then the containment pressure started to decrease significantly. As for the water level in RPV, though it was decreasing at first irrespective of the injection of the water but then has been stabilized though it is significantly below the top of the core.

It is under discussion to use sea water as makeup water after the exhaustion of water in fire-fighting water tank.

It was reported at 15: 35 that the Reactor Building of 1F1 was ruptured after a rather strong earthquake with the sound of explosion and that the level of radiation at the site boundary was suddenly doubled from 500 micro Sv/hr of that after venting operation to 1 mSv/hr. The explosion is considered due to explosion of hydrogen leaked from the primary coolant boundary caused by the impact of the earthquake.

The team decided to complete the preparation to perform this type of feed and breed (F&B) operation in parallel with making their best to recover sea-water line, as key operation in these situation is the F&B operation utilizing venting line until we can recover the operation of sea water system as a heat sink and can use ECCS system.

Accordingly, in the cases of IF Unit 2 & 3, though reactor water level is above the top of the core and core makeup system (either by RICI or HPCI) is in operation, containment venting is in preparation in case the channel to the ultimate heat sink (seawater) is not resumed.

Also in the case of every units of 2F, containment venting is in preparation though offsite power is now available as the path to UHS (sea) is not established.

In the case of iF 4, 5, 6, they were not in operation they were in shutdown state for refueling and maintenance outage.
Pages From C143073-02CX –17 March 12th, 2011 – 1530 – Situation of Fukushima Daiichi – Reactor Building of…

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March 28th, 2011 – The consensus view on the recommendation of not flooding the drywell – Units 2 and 3 are well vented already due to failed containments