Hydrogen leak leading to Fukushima Unit 1 explosion caused by earthquake impact

Author: No Comments Share:

From:Borchrad t. till
Date:Saturday, March 12, 2011 8:10:59 AM

I confirmed receipt

Original Me-ss-ag-e- — —

From: Jaczko, Gregory
Sent: Saturday, March 12, 2011 7:50 AM
To: Borchardt, Bill
Subject: FW:

please confirm that you received.

From: Jaczko, Gregory
Sent: Saturday, March 12, 2011 7:21 AM
To: Borchardt, Bill
Cc: Dorman, Dan
Subject: FW:

updated information

From: Lyons, Peter [[email protected]]
Sent: Saturday, March 12, 2011 7:18 AM
To: Poneman, Daniel; Jaczko, Gregory
Cc: Connery, Joyce; DAgostino, Thomas; Aoki, Steven
Subject: FW:

Kondo-san refers to this as updated version of message to Dan. Thought you all should see it. I haven’t compared to see exactly what is different
from earlier version. This says the explosion was in reactor building.

I still do not understand why the debate re using sea water for cooling – seems to me it should be used.


Original Mes-s-ag-e- — —

From: [email protected] [mailtonshunsuke.kondofllcao.go.ip]
Sent: Saturday, March 12, 2011 7:01 AM
To: Lyons, Peter
Subject: RE:

Dear Dr. Lyons,

Thank you for your kind email. We are in the midst of the fight for cooling down the core without EDGs, experiencing after shocks almost every hour.
Enclosed please find updated version of my note on the situation sent to Dr. Poneman this morning. Just a kind of unofficial personal information.

Shunsuke Kondo

Current ( 15:30 of 2011/03/12) Situation of Fukushima Daiichi (IF, 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 Tf-EQ caused automatic shutdown of all operating units of iF, i.e. unit 1, 2, 3 and 2F, i.e. unitI, 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 scrubbing 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 lmSv/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.

Original Me-ss-ag-e- — —

From: Lyons, Peter [mailto:Peter.Lvons(@Nuclear. Enerev.oov]
Sent: Friday, March 11, 2011 10:40 PM
To: ‘[email protected]’; ‘[email protected]’; i&• AC (T MM
Cc: ‘Y.Sagayama’; [email protected]

Dr. Suzuki and Dr. Kondo

We are watching with alarm the situation in Japan. If you can identify ANY assistance needed in the nuclear plants in Japan, please advise and I will do my best to secure our government’s resources.

Very best wishes
Pete Lyons

Dr. Sagayama – please relay this message to Dr. Suzuki and Dr. Kondo if I have used incorrect emails.


[toggle_simple title=”Related Articles” width=”600″]


Previous Article

Tokyo citizens group close to number of signatures required for nuclear referendum

Next Article

Divided NRC Panel approves Vogtle AP1000 License – Full construction able to begin