ML20006C523
| ML20006C523 | |
| Person / Time | |
|---|---|
| Issue date: | 04/13/1987 |
| From: | Asselstine J NRC COMMISSION (OCM) |
| To: | Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| Shared Package | |
| ML20006C492 | List: |
| References | |
| RTR-NUREG-CP-0084, RTR-NUREG-CP-84 NUDOCS 9002080163 | |
| Download: ML20006C523 (8) | |
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UNITED STATES -
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NUCLEAR REGULATORY COMMISSION j
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WASHINGTON, D.C. 30566 s
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C Prect OF T H :
commissiONan April 13, 1987 I
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MEMORANDUM FOR:
Victor Stello, Jr.
Executive Director for Operations James K. Asselstine I '_
FROM:
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SUBJECT:
NUREG/CO-0084,-PRO NGS OF THE WORKSHOP ON CONTAINMENT PERFORMANCE DESIGN OBJECTIVE I have recently received a copy of the final report of the workshop on a
' containment performance design objective.
I was disappointed to find that the report failed to include the differing views of one of the workshop participants, Mr. Daniel Hirsch, Director, Program on Nuclear Policy,
-University of California, Santa Cruz.
I have received the enclosed correspondence from Mr. Hirsch to Mr. Pratt, l-who served as the rapporteur for the workshop.
It appears to be clear from this correspondence that there was not a consensus among the workshop d
participants on several key issues, including whether containment
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performance design objectives should be developed and what options for CPD0's should be considered. Despite Mr. Hirsch's repeated requests.
l neither his differing views nor the fact of his disagreement were included
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in the report of the workshop.
-Quite frankly, I find it difficult to understand the decision not to include Mr.~Hirsch's views in the report. Among other things..that decision appears to be in direct conflict with the stated purpose of the workshop. The report itself on page A-7 includes the following statement of the objective of the workshop:
What will be sought from workshop participants is views on options and issues -- the ones presented to the workshop t
and any new ones that may emerge from the discussion.
Areas of consensus should be identified as well as areas of disagreement, together with the key issues and arguments involved in significant disagreements.
(emphasis added).
I would like to know who made the decision not to ine.lude Mr. Hirsch's
. views in the report and what the basis was for this decision.
If the decision was made by Brookhaven National Laboratory officials, I would like
- to know what role Dr. Kouts, the Chairman of the workshop, played in the decision.
I would also like to know what advice, either formal or 9002080163 870529 L.' 011. EDO PDR NUREO y
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'.infoma1, was' given by the NRC staff to BNL on the issue of whether to include.Mr. Hirsch's views in the report..and who gave the advice.
If Dr.
Kouts.was responsible for, or involved in..this decision, I would like a.
listing of other NRC work.that'he may be involved in. Finally, I would.
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like to know what options-are available to correct the failure to. include Mr.' Hirsch's views, including reprinting the report with all views of the-
. participants.
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Attachments:
-As Stated v
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.cc: Chairman Zech-Comissioner Roberts Comissioner Bernthal Comissioner Carr-Daniel Hirsch.
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(408) 429-2833 July 29, 1986
- Nm. Trevor Pratt Division Head'
. Safety and Risk Evaluation Division Department of Nuclear mergy Brookhaven National Laboratory Upton, feng Island, New York 11973
Dear Dr. Pratt:
In response to your letter of July 17 requesting comments regarding the draft report of. the NRC's Containment Performance Design Objective -(CPDQ -
a
. Workshop, please find attached my separate comments. Attachment 1 responds to specific items in the draft report; Attachment. 2 is a minority report addressing' matters not addressed in detail in'the draft rep;rt. Please:
- sttach both of them, with this cover letter,- to the final-report when -
m published.-
Please note that-I do not believe that'the draft report is accurate in i
! ascribing consensus among members of the CPDO panel to all the items listed L
in the Executive summary.
I, -for one, do not concur with items 3, 6, and 8.--
, :I:do not believe that the safety goals should merely include a a
p statement that a containment performance design objective will be developed
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li sometime in the future.
In'11ght of Chernobyl,_it is urgent that-containment performance standards be established now, not-further deferred.
I did not agree with the proposed CPDO options, and did propose my own new options. I felt--and Chernobyl has only strengthened tgis view--that the proposed goals of 10-4 probability of core melt and 10- probability of L
containment failure (the basic structure of the various proposed quantitative safety objectives)-are far too lax and would be totally
- their true meanigg. public if. presented in a form that does not obscure unacceptable to the The proposed " goal
- of a probability of core melt 1
accidents of 10' per reactor-year translates into approximately a 40%.
chance of a core melt in the current population'of nuclear plants over their 1
expectec lives, even if NRC were prohibited from granting any new reactor licenses (instead of attempting to make granting of such licenses reasier), and existing reactors met the goal (which they don't), and external 4
initiators such as earthquakes and sabotage, generally excluded from consideration'in'the PRAs on which compliance with such safety goals is estimated, could be ignored (which they can't).- The proposed core melt goal
-translates into an even more unacceptable probability of 60-70% chance of core melt if new nuclear plants are not prohibited and a modest number of additional plants are built (approximately doubling the current population.)
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\\..'1 E onditional probability goal fcr conteinm:nt failuro m
'o core melt cecident did occur (virtually in:vitablo if th310-pans that if
.the 10 c
coro melt-7
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- goal were accepted), a containment failure expectation of 1 in 10 would be 1
7-considered ' acceptable," a kind of Russian roulette gamble I doubt the
-public would find reassuring if explained in plain English.-
I do not believe the Aurican public would accept.a safety goal of a (40-70% probability of a core melt' accident, nnt would they find comforting the fact that. current Peobabilistic plants are coming in around 3 x 10'psk Assessments (PRAs) for U.S. nuclear i.e., falling short of that grossly inadequate goal by a factor of three, tbr would they be comforted that, Loven excluding earthquakes and sabotege, current ' severe core damage cecidents are occuring at about seven times the suggested safety goal rate
. (i.e., about once every 1500-tuctor-years, or about once every seven human
. years with the current worldwide population of reactors). - The PPAs, thus, cppear to underpredict ectual risk of core melt by a factor of two and yet nevertheless show reactora failing to meet the suggeste:3 core melt goal by a N
- factor of three.
.s I further doubt the' public would accept a containment failure goal of
,one in ten, nor would they find. reassuring that current estimates indicate
? failure probabilities as high as 90% for containments such as the Mark I, which thus would fail to meet the proposed containment performance objective by a factor of nine.
y
. Perhaps the most troubling and spectacular aspect of the CPDO Workshop was the conclusion in the analysis performed for the Workshop by NRC and Brookhaven staff that virtually none of the reactor types analyzeo could meet virtually any of the proposed safety goals, and that appears true whether one uses old Reactor Safety Study methodology for analysis or the new ' source term" calculations. ~ In twelve evaluations of reactor containment types against various proposed CPD0 options, there were eleven failures to meet-the proposed goals, a disheartening indication of-the inadequacy of current U.S. containments to prevent majer releases of tn
. radioactivity in, severe reactor' accidents.
The fundamental discussion of the CPD0 Workshop, in~ my view, thus is
'not even mentioned in the draft report: that the proposed Centainment Performance Design Objectives would indicate as acceptable core melt and
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containment failure probabilities that would be clearly unacceptable to the public if published in. plain English, and that, nevertheless, current U.S..
plants can t meet even those inadequate safety goals.
For that reason, a number of the Workshop participants, particularly the industry representatives, argued for publishing no containment performance objectives whatsoever.
I dissented, and continue to do sin er y,
C Daniel Hirsch Director Program on Nuclear Policy cnclosures: Attachment 1.
Comments on Draft Report.
Minority report g
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2 UNIVERSITY OF CALIFORNIA ^. SANTA CRUZ '
'i SEREELEY
- Davis
- IRVINE LOS ANCSLES
- R,YERSIDE SAN DtECO
- SAN 71MNCl&CO SANTA SARBARA
- SANTA CRUE '
M hDLat 3,. STEYENSON COLLEGE -
SANTA CRUE. CALIFOIOGA 980M (408) 429-2833 q
October 30,.1986
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'I wn. Trevor Pratt Division Head If
, Safety and Risk Evaluation Division J
Department of Nuclear mergy 1
-32 I4wis,: Bldg. 130
- Brookhaven. National' IAboratory
-Upton, Long Island, New York 11973
Dear Mr. Pratt:
I~ am in receipt of your letter of October 24, 1986, requesting that I withdraw my dissent from the final report of the NRC's Containment.
J
- Performance : Design Objective (CPDO) panel.- I cannot in good conscience consente o
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,None of:the items to which I objected in the draft report has been.
corrected?, Indeed, the few changes -in the overall text,. in general, further
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weaken an already weak: report. For example, summary item I has been altered-t to suggest, containment is necessary only for the " current generation of.
111ght-water ; reactors," a matter with which the majority of the panel was i
-certainly not in agreement. Item'2 has been altered from a majority of the panel-supporting a CPD0 to only a few so agreeing,' with an extraordinary statement appen6ed that:"many also recognized that-the containment is only-
- one element" in preventing fission product release in case of accident.
If
!there were one thing that the majority of the panel agreed upon, it-was how
. essential"it is to have a proper functioning containment.
.I ccntinue to dissent from items 3,'6,! and 8.in the summary, as well as q,
the representation in the abstract regarding the panel's composition:
4
.. (3) 'I' still vigorously oppose the recommendation that no CPD0 be 0
included in the NRC safety, goal, merely a statement that such objectives B
would be desirable but can t at present be formulated.
I find it.
1 incomprehensible, particularly in light of Chernobyl, that the NRC has no containment performance objectives in its safety goals.
m.
(6) It remains incorrect to say no new CPD0 option was proposed. I proposed such an option, detailed in my minority report, which, unlike the
,j other CPDOs, - might be acceptable to the public.
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( 8)- I continue to object to consideration in a containment objective of hoped-for positive human interventien in the midst of an accident.
a Containments are supposed to be safety features to protect the public when E
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,: operators make mistckest it would be folly to roly on proper operctor cetion
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for a feature that is designed to protect the public from the operator's L
. mistakes.
And the report still inaccurately describes the representation on the panel.
Furthermore, I continue to object to the report's ommissions, i
L particularly its failure to discuss what was, in my view, the most,
significant aspect of the entire CPDO exercise:
(a) that none of the containment objectives, as proposed, would be acceptable to the public if explained in plain English, and (b) that, notwithstanding the unacceptably lax standards under consideration, U.S. reactors apparently could not meet them, often by a very wide margin (11 of 12 evaluatials of reactors against the various proposed goals resulted in failure to meet those goals.) _The e
primary disagreement of the panel was over what to do in light of (a) and (b), with industry representatives arguing that the appropriate response was to not publish any containment objectives at all, to which I vigorously dissent.
It remains incomprehensible to me that, in the wake o#f Chernobyl, there remain no containment performance design objectives for U.S. reactors, particularly in light of the apparent high probability of failure of U.S.
containments in severe accidents (e.g., the NRC's current estimate of 90%
probability of failure for the Mark I).
4 I believe it would be inappropriate and misleading to publish the report without the dissenting comments, so please include this letter and my earlier letter and attachments, copies of which are enclosed.
Si
- ely, i
Daniel Hirsch Director Program on Nuclear Policy
Enclosures:
letter of July 29, 1986 (comments on report) (minority report)
DH:eh
(;f AttachmentJ,
. Comments & Daniel Hirsch to Draft Report f
o_f,the,3,,q Containment PerformanE Design ob7ective Workshop f
h 3,ge cament vii.
?I do not agree with items 3, 6, and 8.
It is thus incorrect to identify them as.' areas - of consensus."
. ~ *
- 3. -I believe that the safety goals'should include containment performance design objectives now. It is unconscionable that after 5 years of considering q3Etitative safety goals, the NRC.
L still has none aside from the vaguest, qualitative social risk statements (e.g.
- nuclear should be no more dangerous than other 1
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major societal risks").- It is unconscionable, particularly in
. light of Chernobyl (which was occurring as our containment Workshop met), that at this late date containments still aren't.
required to be designed to withstand the challenge of a full core L
melt (the very types of accidents where they are needed), and that L
no design requirements exist to assure the containment does what it is.needed to do-remain intact in case of severe accident.
It appears to me an abdication of responsibility to propose at this late date, as this draft report does, that the proposed safety goals include n}o, containment performance objective but merely a o
p statement.that such an objective "will be developed.for use by the H
NRC staff in the future.
a How can the public be assured that reactors are sufficiently safe if the regulatory agency has no standard for measuring their safety, particularly in regards the largest contributor to L
uncertainty about severe accidents-performance of the containment? How can reactor designers know how to design their containments if there is no standard against which to judge them?
How can utilities have assurance additicrial requirements will not be added later to strengthen containments if there is no clear requirement now to assure adequate containment? Most importantly, how can public health and safety be protected when the regulatory agency and regulated industry have essentially no standard for one of the most inportant components of reactor safety?.
6.
It is not true that no new option was proposed by the participants, nor that there was agreement on what a quantifiable CPDo should be. Both I and Shelly indicated we were not happy with the nurbers being proposed for the quantitative goals, feeling they were unacceptably high. I indicated I did not believe it possible the public would accept a goal of a one in ten chance of catastrophic containment failure with major release of radioactivity in case of severe accident, nor for that matter would they accept a 40-70% chance of severe accident as was being proposed with the core melt probability. I proposed as an acceptable goal a containment failure probability of one in a huncred and high confidence that the true probability wasn't higher (defined as a 95% confidence level).
I proposed that the
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- pr:bability cf a coro melt accident occurring s:mewhero in the-Le UJ n during a person's lif; time chould lik3wic3 be on3 in.O
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. hun re, aga n w ti h high confidence. (The Workshop participants
. recognized that, even with statistical high conficance, the probability that something might be overlooked requires
- redundancy-both a low probability of core melt and a low probability of containment failure in an accident. Otherwise, there is no redondancy, no defense-in-depth.)
I also proposed that the quantitative goals be written in a form '
that ooes not' obscure their true meaning fog members of the
- Core melt frequency of 10~ per reactor-year', as general public.
I pointed out at the Workshop, translates to about a 50-50 chance of a core melt over the next forty years or so, excluding
. sabotage.
public acceptance of a safety goal should not be' predicated upon obscuring what it really means. If a 50-50 chance of full core melt is felt to be an acceptable goal by the NRC, the agency should have the courage to say so, not, obscure the goal-in statistical terms of scientific notation unfamiliar to the public and using essentially meaningless concepts like " reactor-year."
8.
I dissent from the assertion that a containment performance objective should include consideration of the positive aspects of human performance. The whole theory of defense-in-depth, the entire basis for the need for ecmtainment, is that you can't count on people to do the right thing, particularly in an accident, and that you need some independent backup system that will, with high confidence, contain the results of human error so as to prevent the public from being harmed by such mistakes. To reduce the requirements for containment performance on the assumption of appropriate human performance belles the very reason for having containments in the first place.
- p. iii I am aware of no Workshop participants who were, as indicated in
- the Abstract.(and repeated in the Introduction at page 1-1),
" representing...public interest groups." I think it is a failure that there 'were none, and that the Workshop was so heavily weighted with industry representatives. Of the sixteen participants, there were two participants associated with the utility organization EPRI (Zebroski and Leverett), two from specific nuclear ' utilities (O'Donnell from GPU and Boyer from
.I Philadelphia Electric), two from reactor vendors (Parrette from Combustion Engineering and Nmme from GE), and one from a major j
reactor architect engineering firm (Gardner from Stone & Webster).
1 Of the. remaining nine, three were from national nuclear laboratories (Hodge from Oak Ridge, Kouts from Brookhaven, and Von Riesemann from Sandia), two were members of the NRC's Advisory Committee on Reactor Safeguards (Siess and Kerr), two were from universities (Theofanous and myself, both from the University of California), one from an incependent t'echnical consulting firm (Sholly from MHB Associates), and one was from American Nuclear Insurers (Mariani).
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