Letter from the Atomic Energy Control Board
(followed by comments from CCNR)
Letter from the Atomic Energy Control Board Comments from CCNR
|
September 30 1999
Ms. Kristen Ostling
National Coordinator
Campaign for Nuclear Phaseout
1200-1 Nicholas Street
Ottawa Ontario
K1N 7B7
Subject:
Quantity of Plutonium that an Atomic Radiation Worker
and the Public may Inhale to Reach their Respective LimitsDear Ms. Ostling:
The Atomic Energy Control Board (AECB) does not set maximum permissible quantities of radionuclides for workers or the public. Regulatory protection criteria are expressed in terms of effective dose limits.
In this context, we understand your question to mean: "What is the quantity of plutonium oxide, if inhaled, would give rise to an effective dose of 50 mSv [ millisieverts ] to a worker or 5 mSv to a member of the public?"
As the result of an intake, these doses will be received over 50 years by a worker and over a period ending at age 70 by a member of the public. These calculations have been made for insoluble (in lung fluid) plutonium oxide of 1 micrometer size. These assumptions are very conservative (restrictive); in other words the worst case scenario has been assumed.
workers:
1.4 micrograms for 50 mSv committed effective dose
(over 50 years after intake)public:
0.1 microgram for 5 mSv committed effective dose
(up to age 70)If you have any other questions, please do not hesitate to contact me at (613) 996-5637.
Yours truly,
M. P. Measures, Ph.D.
Director
Radiation and Environmental Protection DivisionComments from CCNR
Foreword
Plutonium is a highly toxic material. Attempts to deny or to obscure this fact are, we feel, irresponsible.
Some spokespersons for AECL and for the Government of Canada have suggested that there is no danger involved in MOX transport worthy of anyone's serious consideration.
We feel compelled to point out that, although the probability of a severe accident that would release plutonium to the atmosphere is admittedly small, the potential health and environmental consequences of such an accident can be serious due to the extraordinary toxicity of plutonium when inhaled.
It is for this reason alone that the United States of America has made it illegal to transport plutonium by air in US territory. Such a prohibition does not exist for any other radioactive material.
Atomic Energy of Canada Limited has admitted, in documents submitted to Transport Canada, that in four out of eight categories of serious road transportation accidents, the MOX containers would be completely destroyed and a plume of plutonium dust would be spread downwind to a distance of about 80 kilometers.
Transport Canada has stated -- not once, but several times, in its response to public commentaries about AECL's plans for MOX transport by road -- that transporting MOX by air is much more dangerous than doing it by road because of the health dangers of inhaling plutonium dust following an accident.
Industry and government spokespersons have insisted that120 grams of plutonium is too small an amount to raise legitimate health and environmental concerns. They have made the irrelevant observation that 120 grams of plutonium is about the size of two A-A batteries.
Such remarks are manipulative in nature; they do not help people to weigh the risk. The important quantity is not the VOLUME or MASS of plutonium, but its TOXICITY. Based on data supplied by AECB (see letter above) we can address the toxicity question as follows:
0.1 micrograms | can overdose | one civilian |
0.1 grams | can overdose | one million civilians |
1 gram | can overdose | ten million civilians |
100 grams | can overdose | one billion civilians |
600 grams | can overdose | six billion civilians |
if NONE of the plute is safely contained | there is a potential for | one billion two hundred million civilian overdoses |
if 90 percent of it is safely contained | there is a potential for | one hundred and twenty million civilian overdoses |
if 99.9 percent of it is safely contained | there is a potential for | one hundred and twenty thousand civilian overdoses |
if 99.999 percent of it is safely contained | there is a potential for | one thousand two hundred civilian overdoses |
1.4 micrograms | can overdose | one atomic worker |
1.4 grams | can overdose | one million workers |
14 grams | can overdose | ten million workers |
140 grams | can overdose | one hundred million workers |
560 grams | can overdose | four hundred million workers |
if NONE of the plute is safely contained | there is a potential for | four hundred twenty-five million worker overdoses |
if 90 percent of it is safely contained | there is a potential for | forty-two and a half million worker overdoses |
if 99.9 percent of it is safely contained | there is a potential for | forty-two and a half thousand worker overdoses |
if 99.999 percent of it is safely contained | there is a potential for | four hundred and twenty-five worker overdoses |
if NONE of the plute is safely contained | there is a potential for | six billion civilian overdoses |
if 90 percent of it is safely contained | there is a potential for | six hundred million civilian overdoses |
if 99.9 percent of it is safely contained | there is a potential for | six hundred thousand civilian overdoses |
if 99.999 percent of it is safely contained | there is a potential for | six thousand civilian overdoses |
Afterword
The probability of a serious accident involving MOX transport is small, but the consequences can be severe. They can also be very long-lived: since plutonium-239 has a half-life of 24,000 years, plutonium contamination can be permanent. It is a betrayal of public trust to pretend that these risks do not exist.
Unlike most shipments of radioactive materials, plutonium shipments are attractive targets for criminals or terrorists, because plutonium is the primary nuclear explosive material from which atomic bombs can be made.
Any attempted hijacking can only increase the risks of unintended releases of plutonium to the atmosphere.
[ Findings on the Toxicity of Plutonium ] [ Bomb Makers Speak Out Against Plutonium ]
[ Canadian airlift of plutonium was illegal ]
[ Plutonium Sub-Directory ]
[ Short Directory ] [ COMPLETE DIRECTORY ]Since March 27th 1996, there have been over
100,000 outside visitors to the CCNR web site, plus
(counter reset July 2nd 1998 at midnight)