The Great East Japan Earthquake

Press Conference

Extra Press Conference by the Defense Minister (11:27-11:37 A.M. March 17, 2011)

Extra Press Conference by the Defense Minister
Time & Date: 11:27-11:37 A.M. March 17, 2011
Place: Press Conference Room, Ministry of Defense (MOD)
(This is a provisional translation of an announcement by the Defense Minister and the Q&A session at the subsequent press conference for reference purposes only)
The original text is in Japanese.

1. Announcements

Since 09:48 this morning we have dumped water from Self-Defense Force (SDF) helicopters on to reactor Unit 3 a total of four times. As for standard safety limit for radiation, at the time of monitoring the radiation level was 87.7mSv at an altitude of 300 feet. We are currently looking into what the radiation levels are after dumping water onto the reactor. After the water dumping exercise finishes, this afternoon a police water truck will arrive at the site. After that, Tokyo Electric Power Company (TEPCO) will undertake some necessary operations, and from there the SDF will bring in 11 fire trucks to spray water on the reactor. Furthermore, the SDF is currently transporting a U.S. military water pump to be used by TEPCO at the power station. This is all I have to report.

2. Questions and Answers

Question:
What led the Ministry of Defense to decide to start dumping water on the reactor this morning?

Minister:
We had planned to do so yesterday, but pushed the operation back as the high radiation level forced us to evacuate. However, the level of radiation there also meant that it was difficult to make a decision about shooting water at the reactor from the ground. Looking at the circumstances, we judged that our window of opportunity for an air drop was limited to today. This is why we decided to do as I just reported.

Question:
When you say that the window of opportunity was limited to today, what exactly do you mean?

Minister:
The emergency headquarters reported that the situation at Unit 3 was such that we needed to do something early today. Prime Minister Kan and I discussed this yesterday, and came to the conclusion that we needed to act.

Question:
I realize that it may be too early to see any results, but what effect do you think dumping water on the reactor four times today has had?

Minister:
In particular, it should limit the spread of radiation. Beyond that, by getting water into the pools at the reactor, we can expect to see the cooling down of the spent fuel. Although we cannot go near the reactor to confirm this, as of right now, based on the data from the emergency headquarters, I expect that we will find that our operation has been a success.

Question:
You said that you will start to shoot water onto the reactor from the ground this afternoon, but will you also continue dumping water from the sky as well?

Minister:
I would like to do so, if necessary.

Question:
Have you verified that the water has actually hit the reactor?

Minister:
It has definitely hit the reactor.

Question:
When you stopped your operations yesterday due to the high measured levels of radiation, just how high were the levels to make you decide to do so?

Minister:
Before I answer that I must first explain how the SDF conducted this operation. Once the decision to start this operation was made, those involved were given the authority to make the final decision about what level of radiation would make it impossible to continue working. We left this decision up to the pilots at the power station. Yesterday the radiation level rose too high. Accordingly you might ask “if nothing has changed at the reactor since yesterday, why stop then but continue on today?” and my answer to that would be “If we don’t do something, the situation won’t get better.” Chief of Staff of the Joint Staff Ryoichi Oriki received the grave decision made by myself and the Prime Minister and judged himself that it was time to order those at the site to begin dumping water from the air.

Chief of Staff of the Joint Staff:
Dumping water from the air was absolutely an emergency measure. Fundamentally, I made the decision that it was the right time to do so based on the situation at the power station and after receiving the instructions of the Minister of Defense and Prime Minister. It’s true that the radiation levels were what they were yesterday and what they are today, and that I ordered the pilots at the reactor to go ahead anyway. We monitored the levels as we worked, and as just reported, the data shows radiation of 87.7mSv at 300 feet. I judged that it was acceptable to work at such a level, and had helicopters dump water on the reactor. I believe that fundamentally it is our duty to do everything we can as quickly as we can, on the condition that we can ensure the safety of the personnel at the power station. This is why I ordered this operation.

Question:
Concerning the 87.7mSv radiation level, how does this compare to the standard safety limit of the SDF? Also, have you confirmed whether or not the radiation has affected the health of the SDF personnel at the power station?

Chief of Staff of the Joint Staff:
87.7mSV is only the amount of radiation being given off at one point in time. The National Personnel Authority has established 250mSV as the standard limit of safety for accumulated radiation. This is the limit that we use as a reference. This will require some conversion. We are currently decontaminating the personnel and aircraft used, and must still measure and add up the amount of radiation received. At the current moment in time, I don’t believe we have detected any threats to the safety of the personnel.

Question:
Some experts are saying that water will have to be dumped from the sky approximately 100 times. At the very least, how many times will you do so?

Minister:
The emergency headquarters and TEPCO are monitoring the situation. We will make a decision on that once we understand the current conditions at the reactor. I don’t know what kind of expert would say that we need to dump water on the plant “100 times.” It isn’t that I think that it’s too much, but we must also consider the health of the SDF personnel at the reactor and other factors as we act.

Question:
So the radiation levels at the reactor did not change since the time of monitoring yesterday, but you judged it was time to act anyway?

Chief of Staff of the Joint Staff:
The height from which we decided to dump the water changed. Yesterday, when we measured the radiation there we found it to be approximately 250mSv at 100 feet, and although we initially thought this would be the best height to work at, we judged that it would be difficult to move forward at such a high radiation level. Today the height from which we worked was different. As said earlier, at a height of 300 feet, or about 100 meters, the radiation level was 87.7mSv. We decided that we could work in the area if we did so at such an altitude.

Question:
For the operation today, from about what altitude was the water dropped, in meters?

Chief of Staff of the Joint Staff:
We have not exactly verified this yet. It’s hard to say, but the first aircraft reported that they worked at a height of less than 300 feet.

(END)

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