ML20236X296
| ML20236X296 | |
| Person / Time | |
|---|---|
| Issue date: | 12/03/1987 |
| From: | Rubenstein L Office of Nuclear Reactor Regulation |
| To: | Hernan R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8712090106 | |
| Download: ML20236X296 (3) | |
Text
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UNITED STATES o
NUCLEAR REGULATORY COMMISSION g
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.E WASWNGTON, D. C. 20555
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December 3, 1987
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MEMORANDUM FOR: Ronald W. Hernan, Senior Technical Assistant Technical Policy & Support Section Policy Development and Technical Support Branch Program Management, Policy Development and Analysis Staff FROM:
Lester S. Rubenstein, Director Standardization and Non-Power Reactor Project Directorate l
Division of Reactor Projects III, IV, Y and Special Projects 1
SUBJECT:
PDSNP COMMENTS RELATED TO THE PROPOSED COMMISSION PAPER ON I
SEVERE ACCIDENT POLICY IMPLEMENTATION FOR FUTURE PLANTS PDSNP has reviewed the RES proposed Commission paper related to the implementation of severe accident policy for future power plant applications.
Our comments are made with consideration of the RES proposed Gramm-Rudman Budget cuts (see Attachment 1), the R. W. Houston memorandum dated November 11, 1987, and with a desire to maintain existing review schedules of the ALWR applications. We also believe that the schedule for development of the severe accident policy requirement should meet the existing ALWR review schedules.
Otherconcernsdealwiththeuseofegplicitnumericalcriteriasuchas the proposed cut off frequency of 10~ between those severe accidents termed "more likely" and those termed " extremely unlikely".
It is not cle staff would handle the uncertainty associated with predicting a 10~gr how the frequency for an accident without establishing a reliability or confidence level for that number, and a NUREG/CR-4812) generally agreed upon PRA calculational procedure (e.g. Draft In essence, the severe accident policy implementation would be achieved if l
10~gnagreeduponcalculationalmethodologycanbeestablishedtosupportthe value for accident frequency. The nuclear industry would then be able to utilize the results of their design specific PRAs to provide acceptable solutions for those severe accidents termed "more likely".
This approach would put the burden on the industry with the appropriate NRC guidance to provide designs acceptable from a severe accident standpoint, and not require the staff l
to develop additional regulations and prescriptive regulatory guides for their implementation.
We believe that this approach would be consistent with the intent of the Commission's Severe Accident Policy Statement which calls for the development of guidance on the form, purpose and role the PRAs are to play in severe accident analysis.
i CONTACT:
D. Scaletti 8712090106 871203 0
PDSNP/NRR PDR ORQ NRRB hh' Ext. 28282 PDR I/
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In general we are in agreement with the comments and approach proposed by-R. W. Houston on this subject in his November 11, 1987 Memorandum.
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,w Lester ubenstein, Director Standardization and Non-Power Reactor Project Directorate Division of Reactor Projects III, IV, Y and Special Projects
Enclosure:
As stated I
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December 3 1987 0
I 2-In general we are in agreement with the comments and approach proposed by R. W. Houston on this subject in his November 11, 1987 Memorandum.
Lester S. Rubenstein, Director Standardization and Non-Power Reactor Project Directorate Division of Reactor Projects III, IV, V and Special Projects
Enclosure:
As stated DISTRIBUTION:
yCentral. File NRC PDR PDSNP Reading DScaletti LRubenstein FHebdon WSchwink DCrutchfield TMurley JSniezek FGillespie FMiraglia TCox CThomas RBarrett MBoyle JRichardson AThadani FCongel RHouston ZRosztoczy TKing D4 PD DS ti:cw uSe tein 12/3/87 12/3/87 i
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UNITED STATES
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j NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555
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' 1987 l
l MEMORANDUM FOR: Walter S. Schwink, Chief Generic Activities Integration Section Inspection, Licensing, and Research Integration Branch, PMAS FROM:
Lester S. Rubenstein, Director Standardization and Non-Power Reactor Project Directorate Division of Reactor Projects III, IV, V and Special Projects, NRR
SUBJECT:
COMMENTS REGARDING RES - PROPOSED GRAMM-RUDMAN BUDGET CUTS You requested comments on E. Beckjord's November 3, 1987 memo' concerning potential FY1988 Gramm-Rudman reductions within RES. Of major concern is the reduction in funds "available to support development of the rulemaking and Reg Guides for implementing the Severe Accident Policy Statement (SAPS) (pages 13-and 14)." For a savings of less than $300,000 (exact amount unclear), RES proposes to delay development of this guidance by at least 1 year. Such a delay is incompatible.with the schedules for the Design Certification hearings for the GE, W, and CE standard plant designs, which are expected to begin the Design Certification process in mid-1990. We believe that such a delay is inconsistent with the priorities set by the Commission with regard to standardization, as reflected in the strategic or 5 years plans.
If such a delay to this program becomes necessary, then an approach that would be less time consuming (and therefore, less costly), yet resolve the need for appropriate cuidance for the three standard designs, is in order.
One acceptable alternative can be found in R. W. Houston's November 19, 1987 memorandum to B. M. Morris (attached) which proposes the staff establish formal interim guidance for the standard designs until the final rules and Regulatory Guides are approved by the Commission. Such interim guidance in conjunction with approved Licensing Review Bases would be applied to the three LWR standard designs currently in-house while the final rules and final Regulatory Guides (upon issuance) would be applied to the advanced reactor designs which are still in the conceptual stage.
CONTACT:
T. Kenyon NRR/PDSNP Ext. 28206 pcm " ' 9 Mp,
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In summary, support of Design Certification for standard plant designs should continue without delay.
Issuance of interim guidance will minimize the impact of this work to RES's budget, since it precludes the issuance of Regulatory Guides or NUREGs regarding implementation of SAP requirements for LWR standard plant designs.
In addition, establishment of such interim guidance will L-lo crystallize the staff's position regarding the final rule and final Regulctory Guides regarding this matter.
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Lester S. Rubenstein, Director Standardization and Non-Power Reactor Project Directorate Division of Reactor Projects III, IV, V a,1d Special Projects, NRR
Enclosure:
As stated
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UNITED STATES y
7, NUCLE AR REGULATORY COMMISSION 7.
E WASHING TON, D. C. 70555 o
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MEMORANDUM FOR:
B. H. Morris, Director Division of Regulatory Applications FROM:
R. W. Houston, Acting Director Division of Reactor Accident Analysis
SUBJECT:
PROPOSED COMMISSION PAPER ON IMPLEMENTATION OF. SEVERE ACCIDENT POLICY FOR FUTURE NUCLEAR POWER PLANT APPLICATIONS You reques ted coninents on the subject paper in your u.morandum da ted November 6, 1987.
This most recent revision continues to reflect the same approach to dealing with severe accident issues on future plants that we found in all of the previous versions.
As you are quite aware, I do not concur in this appruach for a variety of reasons, j
First, the Severe Accident Policy Statement itself articulates quite clearly the set of criteria that the Conmission expects to be applied to future plants.
In particular, it did not direct the. staff to undertake rulemaking activities to achieve the general objectives for Yutu,re plants. Notwithstanding this, it is not necessarily inappropriate for the staff to recommend rulemaking, but, at the very least, such reconrnendations should be justified and presented to the Connission as a recommended alternative among options considered.
I do no find that this paper contains adequate analysis in this respect for any of he three proposed rules.
One of the stated purposes of the proposal is "to codify severe accident requirements prior to initiation of design certification rulemaking on standard plant applications."
To the best of my knowledge..there is no current user request from NRR in this direction and I believe we are still waiting for NRR views based upcn an earlier proposed version of this paper. Meanwhile, as you are aware, there are already three-standard LWR design applications in-house and available evidence seems to show quite clearly that each cf these appli-cations incorporates placs to address the criteria set forth in the Severe Accident Policy Statement, even though there is no explicit regulation that would require them to do so.
Indeed, the NRC staff has already demonstrated that it is feasible to deal with severe accident issues in the context of the GESSAR 11 standard design although admittedly, the adequacy of that review was not tested in the context of a hearing process such as is likely to occur in a certification by rulemaking process.
With respect to this latter process, I believe there is a legitimate question as to whether or not the criteria articulated only in the Severe Accident Policy Statement is an adequate basis for dealing with severe accident issues in an associated hearing.
The advice of OGC on this question is clearly warranted and should be a priority consideration in any proposed rulemaking that would be applicable to proposed standard plant designs.
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specific issues here relate to the criteria in 10CFR50.34(f), the USI/GSI resolutions, and the PRA.
Your currently proposed paper is silent on both of the former although I would guess that you nay envision that these could be 3
dealt with in the context of the two proposed Regulatory Guides.
>With respect to the PRA issue, I note the proposed revision of 10CFR50.34.
I find it curious that the word "probabilistic" is not in the title of the proposed 50.34(h), and that the wording would not make the rule applicable directly to vendor applications for standard designs.
(The same can be said about the implementation statements for the proposed Regulatory Guides.) The Severe Accident Policy Statement criteria for future plants made' reference to the existing CP/HL rule,10CFR50.34(f), that set forth a set of' specific requirements fcr the then active CP and ML applications, arising frcm the TMI-2 accident. Depending upon how one oces the counting, there are at least 4G separate and distinct requirements identified in this rule, only one of which adcresses a PRA.
It would sees" that at least some explanation or consideration of the other 45 items is warranted.
The title of the proposed paper includes the words Safety Goals and the text appears to propose a loose definition of the term "large release" as used in the general performance guideline proposed by the Comission when it published the Safety Goal Policy Statement in Augu;;t 1986. As I believe you are aware we are in the process of developing a revised implementation plan for Safety Goals and interacting with the ACRS on it. A recent SRM from the Office of the Secretary has indicated a concurrence by the Commission on ACRS views on Safety
. Goal implementation. Among other things, the ACRS position is that the Safety Goal objectives shoul'd be used to assess the adequacy of regulations and
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regulatory practices rather than for " narrowly differentiated decisions about specific plants."
The Commission guidance to the staff does, however, provide the caveat that "if information is developed that is applicable to a.particular licensing decision, the Comission endorses consideration of that information as a factor in the licensing decision." This statement is intended to be read in the context of information derived from the perfomance and/or review of a PRA.
j Neither the ACRS nor the Commission guidance makes any distinction between i
present and future plants on this point and this is still a matter to be
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discussed more thoroughly with the ACRS, i.e., whether Safety Goal objectives for future plants should be different from those for present plants, given the Commission's expressed expectations that "the vendors engaged ir. designino new standard (or custom) plants will achieve a higher standard of severe accident safety performance than their prior designs."
What this all means to me is that we have yet to attain staf f, ACRS, and Conmission concurrence on quantitative objectives or targets for new and i
l existing plants, but more importantly, in the context of the proposeo Conmission paper that if new rules are to be adopted for future plants, they may derive from and have a basis in Safety Coal considerations and information derived from PRA, but should not be cast in a fann of the objectives themselves. More specifically, for exan:ple, if existing General Design Criteria are believed to be inadequate in the light of severe ac(.i(Ynt rist and
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3 Safety Goal considerations, then one should consider their potential replacement by new criteria as a design basis, articulated in deterministic fashion so that there can be little doubt on the part of designers, for example, as to how to design an acceptable containment. The general thrust of 3
the two proposed new General Design criteria, in my view, do not achieve this, but rather, leave open the opportunity for endless debate as to the precision i
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or accuracy with which probabilistically framed criteria are or ever can be
- known, in brief, such debate should be relegated to the rulemaking process, l
not the licensing process.
In this rather lengthy comment memorandum, I am trying to be constructive.
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don'tbelievethatthespecificgoalyouhaveset,i.e.,toapp/ytheproposed rules and Regulatory Guides to the present standard plant appli ations can be
. accomplished in a time frame commensurate with the current schddules. What I believe can, and must be done in that time frame, is to accomplish the task set by the Commission in the Severe Accident Policy Statement tn " issue guidance on the form, purpose, and role that PRAs are to play in severe accident analysis and decision making for both existing and future plant designs and what minimum criteria of adequacy PRAs should meet." Although, there is merit to some of the material we have seen in Draft NUREG/CR-4812, which I-believe was prepared to accomplish this task, major revisions are necessary., including the necessity of transforming it into some _dif ferent kind of staff document, perhaps an interim Regulatory Guide. As I have indicated in prior correspondence, I believe this Division (DRAA) is in the best position to do this in conjunction with our ongoing effort to prepare PRA review guidance.
I believe other more specific comments on the proposed Commission Paper have-
. been transmitted to ybu informally reflecting some views of Jerry Hulman an(
Joe Murphy.
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R. W. Houston,' A'cting Director Division of Reactor Accident Analysis l
cc:
E. Beckjord T. Speis y
G. Arlotto B. Sheron J. Murphy L. Hulman F. Miraglio - NRR
- 0. Crutchfield - NRR l
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