Radioactivity of Uranium 237

Finding the rate of radioactivity of Uranium 237 – the synthetic isotope which does not occur in any significant amount in nature – but which was first discovered during photo-fission experiments with uranium in Japan in 1940 – is very difficult.

Before emailing Oak Ridge, I asked Andrew Kishner, who writes:

“Hi Paul,
It’s great to hear from you.

I used a ‘specific activity calculator’ – which you can find online – and determined U-237’s activity is 81,615 Ci/g.

That value uses the following inputs:
[Uranium 237]
Atomic mass: 237.048724
Half-life: 6.75 days

I double-checked the value using an old-school formula (you can find that formula way down the page at this URL

It’s works out the same.

I hope this helps! ”

Thanks Andrew. Certainly does. It’s another of the disappearing “magic bullets”. Kept secret by the USA during the H bomb era and by Britain too. Not surprising as the large amount of natural U in the tampers and Neutron reflectors in those bombs was turned to U 237 by neutron exposure during the blasts. A major source of early dose according to Lapp.

The British H bomb veterans have not heard of it and I am informed. And the Ministry of Defence maintain the uranium fallout on Christmas Island was harmless.


Proc Jpn Acad Ser B Phys Biol Sci. 2011 July 25; 87(7): 371–376.
doi: 10.2183/pjab.87.371
PMCID: PMC3171289
The discoveries of uranium 237 and symmetric fission — From the archival papers of Nishina and Kimura
Nagao IKEDA*1†
Editor: Toshimitsu YAMAZAKI
Author information ► Article notes ► Copyright and License information ►
Go to:

Shortly before the Second World War time, Nishina reported on a series of prominent nuclear physical and radiochemical studies in collaboration with Kimura. They artificially produced 231Th, a member of the natural actinium series of nuclides, by bombarding thorium with fast neutrons. This resulted in the discovery of 237U, a new isotope of uranium, by bombarding uranium with fast neutrons, and confirmed that 237U disintegrates into element 93 with a mass number of 237.”

Mr Abe, Nishina rolls in his grave at your stupidity.

As for local heroes, this is way over the frontal lobes of the South Australia Minister for public works who claimed, when minister for mines, in March 2011 in front of an audience of uranium mining execs on a junket at the Hilton Hotel (The Pay Dirt Conference) “No-one will dies from Fukushima Diiachi.”

The Lancet has not published the Minister’s speech yet.

Though Dr Yamashita, the dude appointed to initially head the monitoring of the health of Fukushima children responded by concocting a new, unique in the world, minimum latent period for thyroid cancer in children of “4-5 years”. A position maintained by the Fukushima Medical university ever since.

Wonder when Yamashita is going to get around to amending his 1998 paper on the matter. He visited Chernobyl many many times. And noted at in his paper that thyroid cancer in Belarus and Ukraine appeared “very rapidly” after the disaster at Chernobyl. He also noted that once induced by the reactor “accident”, the rate of growth of the cancers was “rapid”.

Breathtaking revisionism from Japan’s Mr Chernobyl. And of course, when Yamashita cite’s Chernobyl as a precedent, which he does, he cites himself. And he knows of course that his post 3/11 crap is absolutely contradicted by his own published peered reviewed paper of 1998.

The endocrine system is most important in mediating the body’s response to the damage inflicted by radiological insult.

Kids who have had heir thyroid glands removed would seem to be at a disadvantage in this regard.

During the 1970s the number of new cases of childhood thyroid cases per year was less than 20. For the whole of the nation of Japan.

Since March 2011, the number of new cases of childhood thyroid cases, as determined by Dr Yamashita and the Fukushima Medical University, has totaled 44 (to September 2013). Not for the whole nation of Japan, but merely for the cohort of children living in the affected area of Fukushima Prefecture.

Yamashita and the Fukushima Medical University maintain that none of the afflicted Fukushima children contracted their cancers due to radiological insult from the nuclear disaster of March 2011.

These authorities justify their position by citing Chernobyl research, which, they claim, proves that thyroid cancer in areas close in affected by the Chernobyl reactor disaster did not contract thyroid until after 4 years had elapsed.

Consulting the record shows that Yamashita himself observed that early onset childhood thyroid in Ukraine and Belarus post Chernobyl occurred very rapidly and that once invoked, those cancer grew very rapidly.

Fukushima Medical University staff engaged in the Thyroid health survey of Fukushima children cite sources based on Chernobyl data which the staff claims support 1. A long 4-5 year latent period for thyroid cancer 2. A slow progression of the disease. In fact these sources actually confirm that latent periods in early onset cases of the disease post Chernobyl were very short, and these sources report that disease progression in the early onset cases post Chernobyl was rapid. The authors of these Chernobyl reports include Dr S. Yamashita, formerly of the Fukushima Medical University Fukushima Thyroid Health Survey.

“Childhood thyroid cancer: comparison of Japan and Belarus.
Yamashita S, Shirahige Y, Ito M, Ashizawa K, Motomura T, Yokoyama N, Namba H, Fukata S, Yokozawa T, Ishikawa N, Mimura T, Sekine I, Kuma K, Ito K, Nagataki S.:
“tumors arising in the Chernobyl population began developing with surprising rapidity and short latency.” (Yamashita et. al., 1998, pdf page 2, journal page 204). The authors consider this rapid onset of disease to be notable compared to thyroid cancers which occurred prior to the Chernobyl nuclear accident.

Source: Center for Cancer Control and Information Services,
National Cancer Center, Japan

Matsuda A, Matsuda T, Shibata A, Katanoda K, Sobue T, Nishimoto H and The Japan Cancer Surveillance Research Group. Cancer Incidence and Incidence Rates in Japan in 2007: A Study of 21 Population-based Cancer Registries for the Monitoring of Cancer Incidence in Japan (MCIJ) Project. Japanese Journal of Clinical Oncology, 43: 328-336, 2013 Download Source Data as Excel spreadsheets at

Deposition of gamma-emitting nuclides in Japan after the reactor-IV accident at Chernobyl‘

Journal of Radioanalytical and Nuclear Chemistry
Volume 116, Issue 2 , pp 291-306
Cover Date 1987-12-01

M. Aoyama (1)
K. Hirose (1)
Y. Sugimura (1)

Author Affiliations

1. Geochemical Laboratory, Meteorological Research Institute, Nagamine 1-1, Yatabe, 305, Tsukuba, Ibaraki, (Japan)


The wet and dry deposition of gamma-emitting nuclides are presented for Tsukuba and eleven stations in Japan following the nuclear reactor accident at Chernobyl’. In Japan fallout from the reactor at Chernobyl’ was first detected on May 3, 1986, a week after the accident. Abruptly high radioactive deposition, which mainly consists of131I,132I,103Ru,137Cs and134Cs, was observed in early May. The cumulative amount of131I,103Ru and137Cs in May at Tsukuba were 5854±838 Bq·m−2, 364±54 Bq·m−2 and 130±26 Bq·m−2 (decay was corrected to April 26), respectively. The monthly137Cs deposition in May corresponds to 2.5% of the cumulative137Cs deposition during the period from 1960 through 1982. Most of the Chernobyl’ radioactivities, especially131I, are scavenged from the atmosphere by the wet removal process. end quote.

I have a question for the Fukushima Medical University. When did nuclear industry commence in Japan?

“The Tōkai Nuclear Power Plant (東海原子力発電所 Tōkai genshi-ryoku hatsuden-sho?, Tōkai NPP) was Japan’s first nuclear power plant. It was built in the early 1960s to the British Magnox design, and generated power from 1966 until it was decommissioned in 1998. A second nuclear plant, built at the site in the 1970s, was the first in Japan to produce over 1000 MW of electricity.”

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