Atomic Insights

Atomic energy technology, politics, and perceptions from a nuclear energy insider who served as a US nuclear submarine engineer officer

FEPC Information Sheet for Fukushima Daiichi on March 16 2011

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Update to Information Sheet Regarding the Tohoku Earthquake

The Federation of Electric Power Companies of Japan (FEPC) Washington DC Office
As of 10:15AM (EST), March 16, 2011
Highest Radiation Levels

At 6:40AM (JST) on March 16, a radiation level of 400 milli sievert per hour was recorded outside the west side of the secondary containment building of the Unit 3 reactor at Fukushima Daiichi Nuclear Power Station.

At 6:40AM on March 16, a radiation level of 100 milli sievert per hour was recorded outside the west side of the secondary containment building of the Unit 4 reactor at Fukushima Daiichi Nuclear Power Station.

At 8:47AM on March 16, a radiation level of 150 milli sievert per hour was recorded outside the secondary containment building of Unit 2 reactor of Fukushima Daiichi Nuclear Power Station.

At 8:47AM on March 16, a radiation level of 300 milli sievert per hour was recorded between the exteriors of the secondary containment buildings of Unit 2 reactor and Unit 3 reactor of Fukushima Daiichi Nuclear Power Station.

At 8:47AM on March 16, a radiation level of 400 milli sievert per hour was recorded outside the secondary containment building of Unit 3 reactor of Fukushima Daiichi Nuclear Power Station.

At 8:47AM on March 16, radiation level of 100 milli sievert per hour was recorded outside the secondary containment building of Unit 4 reactor of Fukushima Daiichi Nuclear Power Station.

At 10:40AM on March 16, a radiation level of 10 milli sievert per hour was recorded at the main gate of the Fukushima Daiichi Nuclear Power Station.

At 4:10PM on March 16, a radiation level of 1530 micro sievert per hour was recorded at the main gate of the Fukushima Daiichi Nuclear Power Station.

For comparison, a human receives 2400 micro sievert per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6900 micro sievert per scan.

Fukushima Daiichi Unit 1 reactor

  • At 6:55AM on March 16, the pressure inside the reactor core was measured at 0.17 MPa. The water level inside the reactor core was measured at 1.8 meters below the top of the fuel rods.

Fukushima Daiichi Unit 2 reactor

  • At 6:55AM on March 16, the pressure inside the reactor core was measured at 0.043 MPa. The water level inside the reactor core was measured at 1.4 meters below the top of the fuel rods.

Fukushima Daiichi Unit 3 reactor

  • At 8:37AM on March 16, white smoke was observed emanating from the vicinity of the secondary containment building.
  • At 9:55AM on March 16, the pressure inside the reactor core was measured at 0.088 MPa. The water level inside the reactor core was measured at 1.9 meters below the top of the fuel rods.
  • At 11:32AM on March 16, the Japanese government announced that the possibility of significant damage to the primary containment vessel was low.

Fukushima Daiichi Unit 4 reactor

  • At 4:08AM on March 15, the temperature of the spent fuel pool was measured at 183 degrees Fahrenheit.
  • At 5:45AM on March 16, a fire occurred in the vicinity of the third floor of the secondary containment building.
  • At 7:26AM on March 16, no flames or smoke was observed and thus it was concluded that the fire extinguished on its own accord.

Fukushima Daiichi Unit 5 reactor

  • At 4:00AM on March 16, the temperature of the spent fuel pool was measured at 141 degrees Fahrenheit.

Fukushima Daiichi Unit 6 reactor

  • At 4:00AM on March 16, the temperature of the spent fuel pool was measured at 137 degrees Fahrenheit.

Rokkasho Reprocessing Plant and Accompanying Facilities

  • As of 12:00PM on March 15, power generation of all facilities was restored to the commercial electricity grid from backup power generation systems. It was confirmed that no fire, damage to equipment, injuries to personnel occurred. Radiation levels were measured at a normal level of safety.

This update conflicts with the rumors that have been flying around regarding the state of the used fuel pool at unit 4. Though the temperature in the pool is high enough to cause operators to worry a bit about getting some cooling water into that pool before it gets too much hotter, it is still almost 20 degrees F below the boiling point of water.

The talk about getting a fire hose to fill the pool brings back a very intense memory for me of one of my duty days as the engineering duty officer. Without getting into any details, I ended up having a very stern talk with the tender’s DC Central about my need for a fire hose. After the person on the phone gave the order to get a fire hose down to us NOW, he came back on the line and introduced himself.

It seems that the tender XO was making a round and happened to be in DC Central at the time that I called. As an ensign, I was chewing out a commander. I managed to obtain the services that my ship needed, but oops.

Reader Interactions

Comments

  2. I posted this on my FaceBook Page. Thanks for the facts Rod and not the overblown Alarmist Talking Points!!!

  3. Thank you very much for your very informativ blog – it gives very interesting insights. Do you have any sources, that can say how high the radiation levels are, split between Alpha, Beta and Gamma rays / cores? This would significantly help to understand the situation of the operators in the plant.

  4. It is going to be very important to have a valid time line of events available once this settles down. It was far too long before reliable ones were produced for TMI and Chernobyl , and that delay gave too much time for speculation by the media that helped make these events look much worse than they were. The sooner the truth is out, the better it will be for the public to put this event into perspective.

    • I’m worried that we will never know the true story of what exactly happened for cultural reasons.

  5. Am I the only one to question the Appx 2 meters below top of fuel rods for water levels in the cores???? I didn’t think this was “A Good Thing”. ex MM1 Nuke here, currently shutdown mechanic working on MOV’s.

    • I think some of the info may be getting lost in translation, or just a typo (hopefully).
      I’ve given others a hard time for making judgments without all the facts, but I’m starting to question the performance of their operators. I just can’t believe that an US plant staff would have allowed the spent fuel pool level to drop on Unit 4, with or without the explosions and radiation. Other countries may be as good too, I just haven’t worked on their plants to know.

  6. Ensign chews out a CDR? Too bad that’s the climax of a sea story I’d like to hear. How about a female MRFN chewing out a Marine in his skivvies while brandishing an M-16 (the Marine, not the MRFN)? Different tender, I’m sure– an AD.

    • There is a new wave of hysteria about the spent fuel ponds. Nobody seems to notice that the reactor cores seem to have been stabilised, as seen on http://www.jaif.or.jp/english/ . Since when is a lack of water in a spent fuel pool “another Chernobyl”?

      • @Jerry – I think that there are some people who have been working on convincing themselves for years that used fuel pools are a source of great concern. They have commissioned studies to determine “the worst case” of what would happen if all of the material in the pool suddenly turned into powder, lofted itself airborne and rained down at just the right place to impact as many people as possible.
        They have fooled themselves into believing this fantasy and they are selling it hard. The problem is that the real world of thermodynamics, chemistry and physics does not work like that. There are physical rules that must be obeyed, no matter who you have worked for in the past (Markey and Reid) or what you want to have happen. Water does not boil off without a lot of heat applied quickly (power). Temperature does not do it, energy does. Radioactive decay only generates a certain quantity of energy, and physical materials like water and the tank liner transmit a good bit of that energy away, limiting the rate at which fuel temperatures can rise.
        Remember, 95% of the material in a used fuel pool is already oxidized and cannot burn, no matter how many times someone writes about it or how many models – with many simplifying assumptions – show that it will.

  8. I would think that anyone involved in a tense situation while tending uranium outranks even an admiral.

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