4/5 Discussion on Beyond Nuclear: NYT reports new threats at FNPP reactors

Another "What do you think about this?" thing.  Not sure if the discussion took place on early to mid-April, but it's one of the April discussion anyway.

Tristan Gribbin

I don't know if you've seen this article from the NY Times from April 5th? It analyzes the leaked NRC Report in depth and explains that the catastrophe at Fukushima is far from under control. There are many dangers that will only be averted if the right measures are taken. The article clearly outlines the challenges ahead.

Beyond Nuclear - Home - New York Times reports new threats at Fukushima Dai-Ichi reactors

Frank Sanns

If I may interpret the most important data from the actual NRC report that was posted. I can not verify that it is authentic but the details are scientifically sound and I believe the report to be accurate. The most important statement for those in Japan is this portion of the report is "neutron sources found up to I mile from the units". This is important for the fact that there are NO naturally occurring neutron sources in nature and no gaseous emanations of nuclear plants emit neutrons. ONLY and ONLY core material does. Interpretation is Uranium and Plutonium were ejected from the plant and found well outside of the plant perimeter. This material was ejected as fine particles via a "burn" of fuel or by a steam or hydrogen explosion from a fuel pool or reactor. The density of uranium and plutonium is very high (heavy) so it is not typically carried long distances in the wind so it is unlikely that Tokyo has received any of this material but the people should have been informed of this information as it may have been prudent to stay inside on the day or two following that event. I hope that a repeat of this does not happen but if the plant is temporarily evacuated again, it may be prudent to stay indoors as much as possible for 2 or 3 days following such an event just as an extra safeguard. The day to day radiation levels measure and the radioactive materials measured by TRL continue to be at a very safe level and I do not see any reason for any concern but I would push those in charge in Japan for more timely and complete disclosure of what is being put into the air over Japan. There is a great danger that there would be irrational and unfounded panic but I think people have the right to know. If TRL feels this language is too strong for his site I will understand if he choses to delete it as his service is invaluable to the people of Tokyo and my technical and one line political statement my not be consistent with his mission here.

Carlo ‎@Frank, I remember very well they said that "nothing" leaked from the reactors during explosions here in Japan "just the shell exploded so no need to worry".

Frank Sanns Either the report is wrong ( not likely) or they lied (likely). :-(

Pje I'm not sure whether this relates to what you're discussing, but findings of plutonium were reported last month: "After taking soil samples at the Fukushima Daiichi nuclear power plant, Japanese authorities today confirmed finding traces of plutonium that most likely resulted from the nuclear accident there". Sources / DATE 28 MARCH :http://www.iaea.org/newscenter/news/2011/fukushima280311.html

Frank Sanns @pje It is not the presence of plutonium alone that is of concern it it the quantity that was detected that is of concern. Modern analysis techniques can detect quantities so small that they are nearly meaningless. Parts per billion or trillion and beyond are the norm for detection. The significance is that they detected neutrons. Plutonium emits just an occasional neutron and it is not a strong source of them so you need an appreciable quantity of plutonium to detect them. On top of that neutrons are not easy to detect. Milligram to gram quantities of plutonium per square meter would have to have been present to detect the neutrons. It is not news that plutonium was detected, it is news that large quantities were detected.

Carlo There is also reference to "neutron beam" detected by TEPCO from March 13th during 3 days (reported on March 23rd thought) :
http://english.kyodonews.jp/news/2011/03/80539.html

James Thank you Frank for your assessment. You mention that you think its unlikely that Tokyo has received any of this material.  But if it has, would it be detected in the hourly radiation amounts?  In other words, how can we monitor the situation ourselves to see if there is danger here in Tokyo.

Reisel Mary If or when the situation will be stable, we could try them to monitor the situation. But as long as things are so fluid and changing, I think it's very hard. I never know what news we're going to have in the morning, it's impossible to know something for sure.

Frank Sanns

‎‎@Carlo, In the context of a shut down reactor or raw nuclear fuel, there cannot be a neutron beam. An opening in the shielding can let what might be described as a beam of neutrons stream out of an operating reactor but it must be operating with much active fission occurring. The article that you referenced was most likely describing an active debris field of reactor fuel in which neutrons were being detected. This would have to be a significant debris field to be detecting neutrons.

‎‎

@James, I am fairly confident that Tokyo would not have received much of this material. Although milligrams were present 2 km from the site, Tokyo is a long way from the reactor site and the winds would have had to been strong on those days and directly at Tokyo. I do remember that there was one day that the Iodine spiked but I am traveling today and do not have the opportunity to cross references those dates with reactor events. If any day was so it would have been on that day or days.  [And] to monitor for plutonium the most reliable is an alpha only probe. A setup used would cost about 600 USD. Unless there is much radon in an area, this would be the most reliable methode.

‎@Mary, I empathize with you but I think there is very low risk of anything of significant health hazard in Tokyo occurring. If something really catastrophic happened, you would have a days warning because of the distance. Staying indoors would essentially make the risk zero on those days if something were to happen. Do not worry but keep a little diligent over the next couple of months.