Discovery of Neptunium-239 in Iitate-mura Finally Published by a Peer-Review Magazine (Nearly One Year after the Discovery)

A paper by a researcher at Tokyo University about discovery of neptunium-239 and other short-lived nuclides in Iitate-mura seems to have finally been accepted and published by Environmental Pollution, a peer-reviewed scientific magazine. It was made available online on January 20, 2012, and is published in the April 2012 issue of the magazine.

It took nearly 1 year for off-line readers to know about the discovery. The researcher took the samples of soil, plants and water in early April last year.

In August last year there was an article of neptunium-239 having been discovered in Iitate-mura, 35 kilometers from Fukushima I Nuclear Power Plant, by a researcher at Tokyo University. The article was written by a husband and wife comedian couple. (For more, see my post on August 15, 2011.) They were criticized for not revealing the source (name of this researcher) or the details. Their response was that the researcher was submitting the paper to a peer-reviewed magazine.

Well here it is, published by a peer-reviewed magazine nearly one year after the accident, and now utterly irrelevant except for some academic curiosity. The information, as it sat in limbo of peer-reviewing process, was not used to educate, warn people in Fukushima, particularly in Iitate-mura, so that they could decide what to do. If they had known their soil and vegetation were extremely contaminated with short-lived radionuclides with strong radioactivity, they might have done things differently.

I hope the researcher at least warned the villagers privately.

From Sciencedirect.com:

Environmental Pollution

Volume 163, April 2012, Pages 243–247

Deposition of fission and activation products after the Fukushima Dai-ichi nuclear power plant accident

* Katsumi Shozugawa (a), Corresponding author
* Norio Nogawa (b),
* Motoyuki Matsuo (a)

* a Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
* b Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan

* Received 22 August 2011. Revised 24 December 2011. Accepted 1 January 2012. Available online 20 January 2012.

Abstract

The Great Eastern Japan Earthquake on March 11, 2011, damaged reactor cooling systems at Fukushima Dai-ichi nuclear power plant. The subsequent venting operation and hydrogen explosion resulted in a large radioactive nuclide emission from reactor containers into the environment. Here, we collected environmental samples such as soil, plant species, and water on April 10, 2011, in front of the power plant main gate as well as 35 km away in Iitate village, and observed gamma-rays with a Ge(Li) semiconductor detector. We observed activation products (239Np and 59Fe) and fission products (131I, 134Cs (133Cs), 137Cs, 110mAg (109Ag), 132Te, 132I, 140Ba, 140La, 91Sr, 91Y, 95Zr, and 95Nb). 239Np is the parent nuclide of 239Pu; 59Fe are presumably activation products of 58Fe obtained by corrosion of cooling pipes. The results show that these activation and fission products, diffused within a month of the accident.
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Highlights

► We collected environmental samples near the Fukushima nuclear power plant. ► We observed 239Np and 59Fe along with many fission products. ► 239Np is evidently an activation product of 238U contained in nuclear fuel. ► 239Np is also parent nuclide of 239Pu. ► Our results show that activation products diffused within a month of the accident.

If the data in the paper is not much different from what the researcher had put on his own website last year, Iitate-mura had several thousand becquerels/kg of neptunium-239, exceeding one of the two sampling locations in front of the Fukushima I plant gate. Iitate-mura also had a host of other radionuclides in amounts exceeding the immediate vicinity of the plant or the front gate of the plant or even inside the plant.

You can see the charts for yourself, here. They are from the researcher's presentation last year, not from the paper submitted and accepted at Environmental Pollution.

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Ministry of Education Admits to Plutonium in Iitate-mura in Fukushima

35 kilometers northwest of Fukushima I Nuclear Power Plant.

Jiji Tsushin (5:42PM JST 9/30/2011):

文部科学省は３０日、福島県双葉町と浪江町、飯舘村の土壌から、福島第１原発事故によるとみられるプルトニウムが検出されたことを明らかにした。同原発の敷地以外で、検出されたのは初めてという。

Ministry of Education and Science disclosed on September 30 that plutonium has been detected from the soil in Futaba-machi, Namie-machi and Iitate-mura in Fukushima Prefecture, which derived from the Fukushima I Nuclear Power Plant accident. According to the Ministry, it is the first detection of plutonium outside the plant.

Readers of this blog have been alerted to the existence of neptunium-239 (which decays into plutonium-239) in the soil of Iitate-mura, so it should be no surprise. It is no surprise at all either that it has taken more than 6 months for the Ministry of (Re-)Education to admit.

Neptunium-239 has reportedly been detected in Date City also. That's even further away from the plant (60 kilometers).

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Nikkan SPA Magazine: Researcher Says Large Amount of Neptunium-239 Also in Date City, Fukushima

It's the same researcher who said several thousand becquerels/kg of neptunium-239 was found in the soil in Iitate-mura, about 35 km northwest of Fukushima I Nuclear Power Plant. It seems it's not just Iitate-mura that got doused with neptunium, which decays into plutonium. Date City, about 25 km northwest from Iitate-mura and 60 km from Fukushima I Nuclear Power Plant, also got a large amount of neptunium.

To recap, uranium-239, whose half life is about 24 minutes, decays into neptunium-239 with a half life of about 2.5 days, which then decays into plutonium-239 whose half life is 24,200 years.

Again, the reason for withholding the information is explained in the article below as "the research paper being peer-reviewed by a foreign scientific journal" - a make-or-break event, apparently, for a young researcher at a prestigious university in Japan - and as precaution against the possible Japanese government action to squash the information. The article was written by the same husband & wife comedian couple who first wrote about neptunium in Iitate-mura on their blog magazine in early August.

I'm sure the nuclear experts who have appeared on TV to soothe the populace ever since the March 11 nuclear accident has the good explanation for neptunium-239 in these locations. They've kept saying "No way plutonium will be found outside the compound, because it is heavy and it doesn't fly". Oh I get it. It's plutonium they were talking about, not neptunium which decays into plutonium. My bad.

From Nikkan SPA September 13 issue (part on Date City only):

メールはこう始まっていた。

The email began thus:

「放射線測定を専門とする大学研究者に直接聞いたのですが、プルトニウムが核変する前のネプツニウムという核種が、少なくとも飯舘村や伊達市まで大量に飛んでいたそうです。今のγ線メインの測定方法ではどんなに頑張ってもセシウムしか検出できないため、本来の危険性が見逃されてしまう。α 線核種を無視した今のやり方を続けていたら、飯舘村はまた“見殺し”にされかねない……」

"I heard it directly from a university researcher whose specialty is radiation measurement. Neptunium, the nuclide that decays into plutonium, flew at least to Iitate-mura and Date City in large quantity. The current survey method focuses only on gamma ray, and all it detects is radioactive cesium. The real danger is alpha-nuclides, which continues to be ignored. Iitate-mura may be being betrayed again..."

The article by the comedian cum independent journalist couple continues and says this person attended a lecture given by this researcher.

It still doesn't make sense to me that the information already freely given at a public lecture has to be withheld because of the peer-review process, but oh well.

Date City by the way has been selected by the national government to conduct "decontamination" experiments. So is Iitate-mura. They are using high-pressure spray washers to blast roofs, sidings and roads, and digging up the soil. Plutonium? What plutonium?

Unlike Iitate-mura, though, almost all residents in Date City still live within the city. Even those who are ordered to move because of high radiation level in their homes have moved to temporary housing that the city has provided, within the city.

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(UPDATED) NISA Mentions "Neptunium-239" in August 29 Press Conference

(UPDATE on 8/30/2011: NISA still hasn't said a word about conversion, but someone in Japan did the calculation based on the NISA's numbers released on June 6. You can view it at this link or in the image below. In plain language, neptunium-239 will decay into plutonium-239, adding 2×10^7 becquerels (20,000,000 becquerels) to the existing plutonium-239. The calculation was done by Tomohiro Endo, a researcher (nuclear physics) at Nagoya University.)

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(UPDATE on 8/29/2011: NISA backtracked in the joint conference (TEPCO/government) in the afternoon, and now says it's not sure about the conversion rate of neptunium-239 into plutonium-239.)

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Now this is very curious.

The Nuclear and Industrial Safety Agency (NISA)'s daily press conference is ongoing (August 29). The NISA spokesman Moriyama mentions neptunium-239's conversion ratio to plutonium-239 as 1 to 1.

According to the June 6 estimate by the NISA:

Plutonium-239: 3.2×10^9

Neptunium-239: 7.6×10^13

So, now it is:

Plutonium-239: 7.6 x 10^13, or 76,000,000,000,000 or 76 terabecquerels

The amount of plutonium-239 has increased 23,000-fold, according to NISA.

On August 15 I wrote about neptunium-239, half life of about 2 days, having been detected in large quantity in Iitate-mura, 35 kilometers from Fukushima I Nuclear Power Plant. I had to take down the second post on the subject, but the information was correct.

Now, NISA is suddenly mentioning neptunium-239. Admission of wide dispersion of this nuclide and resultant plutonium-239 may be finally forthcoming, after more than 5 months.

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Neptunium-239 Detected from Soil in Iitate-mura in Fukushima???

(Correction: my initial post said "several thousand becquerels per kilogram", but on checking the original Japanese post there is no mention of "per kilogram" or per any other unit.)

The information comes from a strange source - the husband and wife comedian couple cum independent journalists attending and reporting on TEPCO and the government press conferences when they are not on stage.

In their blogpost on August 11 (in Japanese), they relate their talk with a researcher at the University of Tokyo who has submitted a scientific paper to a foreign academic society. This researcher, whom they say they cannot name because the paper is being reviewed right now, went to Fukushima and collected soil samples, rice hay samples, and water samples. He even went to the front of Fukushima I Nuclear Power Plant and collected samples there.

He also went to Iitate-mura. And he tells the couple that he found neptunium-239 in Iitate-mura, about 38 kilometers from the plant, in approximately the same amount as he found at the front gate of Fukushima I Nuclear Power Plant. That is the topic of his paper.

The couple says in the very intelligent post that they cannot provide details because the paper is in review (but they also say the researcher has given them permission to talk about it in general terms), but it was in several thousand becquerels. There is no mention of whether it was per kilogram or per square meter or per something else.

There is no mention of when the researcher went to Iitate-mura. I could be wrong but the indication from the post is that it was after the news that chlorine-38 detection at Fukushima I Nuke Plant was false. TEPCO retracted the earlier announcement of chlorine-38 detection, on April 20.

Uranium-239, whose half life is about 24 minutes, decays into neptunium-239 through beta decay. Neptunium-239, gamma emitter whose half life is about 2.4 days, decays into plutonium-239 whose half life is 24,200 years.

If this Tokyo University researcher went to Iitate-mura after April 20 and he was still detecting neptunium-239 whose half life is only 2.4 days, I just abhor to think of the implications. The locations that he found neptunium-239, in Iitate-mura and in front of the plant, were never tested by the Ministry of Education and Science or by TEPCO, according to the post.

Evacuation of Iitate-mura wasn't completed till late May, but not all villagers evacuated. There are still old people living in the village, and the villagers regularly go back to the village to check up on things.

I don't know how much longer Japan can continue to "Extend and Pretend", but probably much longer than anyone outside expects. We'll find out when this paper gets published.

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