[ RadSafe ] Fwd: Global deposition of man made radionuclides

[farber]

Dear Radsafe,
The question posed: "total global inventory of "anthropogenic radionuclides (e.g., Cs-137, Sr-90, Pu-239, etc.) as a result of releases over the past 14 years” has what I would suggest has a surprising answer.  I would suggest that on a global basis the total environmental inventory of Cs-137, Sr-90, and Pu-239 has quite simply declined over the past 14 years.

Korean nuclear tests were underground, not in the open atmosphere, so releases, if any, would have been trivial. The releases from Fukushima and any other nuclear accidents suggested were not sufficient to affect the total inventory of the anthropogenic radionuclides on a global scale.

The reason for this is perhaps surprising and simple. The figures presented are quite approximate, but approximate numbers should suffice. The residual global environmental inventory of Cs-137 as of 14 years ago might have been on the order of 10,000,000 Curies from all preexisting open air nuclear tests and residual activity from the Chernobyl accident.  10E6 Curies of Cs-137 would be reduced from decay by about 230,000 Curies/year. Any and all routine operations of nuclear facilities worldwide and any accidental releases would not have released anything close to 230,000 Ci to the environment.

Accordingly, the global inventory of Cs-137 will have declined. The same applies to the annual decay of preexisting Sr-90 global inventory ( on the order of 5 Mega Curies as of 14 years ago)   and any releases of Sr-90 over the last 14 years being insufficient to increase the global inventory. 

Ditto on an even more dramatic fashion to Pu-239.  I don’t  have figures for the preceding at hand, but as of the late 1970s, atmospheric nuclear bomb testing had released something like 6,000 kg ( 350,000 Ci) of Pu-239 into the open atmosphere, which deposited globally.  The decay of 6,000 kg of Pu-239 from bomb testing would equate to a decay of about  11 Ci per year.  The releases of Pu-239 from operation of 500 nuclear plants worldwide (including reprocessing), and any and all accidents would be insufficient to maintain the preexisting environmental inventory.

Much of North Carolina is being devastated today by the effects of Hurricane Florence. Rivers have not yet crested in many areas and the damage and fatalities locally in NC and SC will increase. I’m fortunate not to be near the coast of any rivers that are far above flood stage. But over large areas of the Carolinas, If you know anyone check how they are doing.

Best, 

Stewart Farber, MSPH
Farber Medical Solutions, LLC
1309 Quincy Cottage Road
Hillsborough, NC 27278
203-522-2817 (mobile)

> Begin forwarded message:
> 
> From: "dcoble at tds.net" <dcoble at tds.net>
> Subject: [ RadSafe ] Global deposition of man made radionuclides
> Date: September 13, 2018 at 11:06:18 AM EDT
> To: "The International Radiation Protection (Health Physics) Mailing List" <radsafe at health.phys.iit.edu>
> Reply-To: "The International Radiation Protection \(Health Physics\) Mailing List" <radsafe at health.phys.iit.edu>
> 
> Dear Colleagues,
> I am seeking information on the global deposition of anthropogenic radionuclides (e.g., Cs-137, Sr-90, Pu-239, etc.) as a result of releases over the past 14 years. 
> The question to answer is; To what extent has releases from North Korea Nuclear weapons testing, Fukushima Daiichi nuclear plant explosion and other nuclear incidents (e.g., WIPP Pu release to atmosphere Feb. 2014) impacted the background concentration of anthropogenic radionuclides on a global or regional scale? 
> Any assistance in locating reports or papers will be greatly appreciated. 
> 
> Thank you,
> Douglas Coble
> RRPT, RSO 
>