ML19341C881
| ML19341C881 | |
| Person / Time | |
|---|---|
| Issue date: | 02/11/1981 |
| From: | Ahearne J NRC COMMISSION (OCM) |
| To: | Babbitt B NUCLEAR SAFETY OVERSIGHT COMMITTEE |
| References | |
| NUDOCS 8103040357 | |
| Download: ML19341C881 (4) | |
Text
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'%,,,,, #p February 11, 1981 CHAIRMAN COL.;331oN CORRE.SFOSDDICE fVkk'N x2 gl Sf}#\\ }r- "y Governor Bruce Babbitt m'
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20005 nVj Dear Governor Babbitt-
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3 Your letter to President Carter dated December 21, 1980 stated that NRC and DOE should be re' ponding more aggressively to the results of recent s
studies of the release of radioactive iodine in nuclear reactor accidents.
There is no doubt in my mind that the implications of these results have an important bearing on certain of our regulatory activities, particularly emergency planning and accident consequence mitigation.
On November 18, 1980, the Commission was briefed on the subject by Los Alamos and Oak Ridge scientists, representatives of the Electric Power Research Institute, and the Commission staff.
I believe the substance of the briefing was identical to that presented to your Committee.
Following the briefing, I discussed the matter with our staff and, on November 25, 1980, directed them to take prompt action to resolve the technical issues.
As an initial step, a report on the state of knowledge regarding the iodine source term under accident conditions will be completed in March by the NRC staff with assistance from contractors, consultants, and national laboratories. The intent of this status report is to provide a firm technical basis for further action and to indicate what additional work should be done. The report will summarize the existing relevant knowledge on fission-product release and transport inside containment under accident conditions, iodine and cesium iodide chemistry, as well as the effects on performance requirements of engineering safety features.
The results of recent NRC-sponsored research on fission-product aerosols l
and the work described to you by Dr. Malinauskas and Dr. Campbell are to be included in this survey.
The staff of the Electric Power Research Institute and the Nuclear Safety Oversight Committee have been invited to participate in a peer review of this report.
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Governor Bruce Babbitt.
The status report will be accompanied by a staff report on the regulatory implications of our current knowledge of fission-product iodine release in postulated reactor accidents. The 3tatus report may also indicate whether we need to expand NRC work in this area.
In addition to the aerosol release and transport program, the NRC is sponsoring an extension of earlier work on fission-product release from failed fuel to higher temperatures; separate effects tests on fission-product chemistry in various atmospheres; and analytical modeling of how fission products are transported through the coolant system to the containment. Key data developed in this work are being integrated into models for accident consequence estimation.
I share your Committee's views as to the importance of work on accident source terms and I believe the NRC has responded appropriately to this matter.
I regret there was no opportunity to discuss our efforts before you submitted your report.
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John Deutch Marvin Goldberger Harold Lewis 4
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~ij December 21, 1980 The Honorable Jimmy Carter President of the United States The White House Washington, DC.20500.
Dear Mr. President:
Your Nuclear Safety Oversight Committee has recently examined an issue that could have a significant impact'on nuclear safety and regulation.
In sum, there is evidence suggesting that radiological consequences of some nuclear accidents may be substantially less than previously assumed.
~ Scientists at Los Alamos and oak Ridge National Labora-tories have recently examined the unexpectedly low air-borne release:of Iodine 131 at'Three Mile Island and also studied the pattern of iodine releases in past reactor accidents in this country and abroad.
This'research suggests that in light water reactor acci-dents, radioactive iodine fission products may not be re-leased as'a gas as previously assumed in the Reactor Safety Study (WASH 1400) and other studies.
In the reducing atmos-phere likely to be present in most light water reactor acci-dents, tha new studies suggest that radioactive iodine would
. combine with cesium and enter into water solution.
If this assessment, which to our knowledge has not been refuted, proves correct, it would have major implications for such regulatory issues as plant siting and emergency planning, because the potential exposure of the neighboring population in the event of a major accident would be much lower than previously o
assumed.
In our view, the Nuclear Regulatory Commission and the Department of Energy should be responding more aggressively to this important development.
There are outstanding technical questions surrounding the hypothesis that can and should be answered by analysis and experimentation.
In our judgment, you should press for a coordinated research effort that would verify or refute this hypothesis about iodine behavior.
This technical question should be resolved on an expedited basis
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"he Honorable Jimmy Carter Page Two December 21, 1980 I
for it bears directly on fundamental assumptions underlying some of the most important regulatory issues facing the nation.
The dodine release question is part of a broader constella-tion of issues involving source term estimates of the amount of radioactivity that should be expected in the event of a major accident.
We believe that the entire set of issues, including
_ fission product chemistry and aerosol forme.cion and behavior in
+ accident environs, deserves increased attention as well.
It would be helpful if you would designate someone from your staff to discuss this matter with us.
Respectfully,
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. Bruce Sambitt Chairman a
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