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BROOKHAVEN NATIONAL LABORATORY
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..a.n CT I I E L L.:lA ASSOCIATED UNIVERSITIES, INC.
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Upton. Long Isicnd. New York 11973 (516) 282s 2444 Department of Nuclear Energy FTS 666' February 13, 1984 4
Mr.' Warren Lyon
~ Reactor Systems Branch Division of Systems'In'tegration Office of' Nuclear Reactor Regulation
' Mail Stop P-1132 U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Mr. Lyon:
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Enclosed is the January monthly report for the activities sponsored by your Branch.
Also included are the computerized budget summaries and the fee recovery cost status for each program.
I would suggest that you and your staff review the reports to determine whether there are any discrepancies.
If there are, please notify the principal investigator.
We hope this raeets wich'your approval.
If there are any questions re-garding format, distribution, or budget reporting, please contact Mr. A. J.
Weiss, Administrative Technical Assistant, FTS 666-4473.
Sincerely yours, l6 Walta
. Kato Depu y Chairman WYK/jw Enclosures cc:
R. Bari, BNL S. M. Boyd, NRC D. J. Corley, NRC k THIS COPY MR (
R. Hall, BNL W Houston, NRC J. Rosenthal, NRC B. Sheron, NRC A. J. Weiss, BNL BNL Technical Monitor 8505230365 841002 NLL 243 PDR
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Division of Systems Integration NRR l
January 1984 Total Projected Funds Obligated Balance of Funds (SK)
FIN No.
Project Cost ($K)
To Date (SK)
FY 1984 FY 1985 FY 1986 A-3712 180 180 0
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.4 MONTHLY HIGHLIGHTS FOR JANUARY 1984 t
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" Safety Evaluation of Core-Melt Accidents:
f Indian Point-OR and Zion-0R" f
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(FINA-3712) 1 I
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l BNL Principal Investigator:
W. T. Pratt (FTS 666-2630)
I NRC Project Manager:
W. Lyon (FTS 492-9405), RS Branch l
1.
Scope /
Purpose:
The scope of this work will be limited to addressing immediate NRC/NRR licensing concerns using the state-of-the-art codes and the analyses and experimental data developed from NRC/RES and other R&D programs.
The analyses provided under this contract helped form the basis for positions l
taken by the NRC staff as related to questions raised by the Commission, hearing board and intervenors as part of the Indian Point Hearing. Al so,
the analyses will provide input to the NRC staff's review of the Indian Point Probabilistic Safety Study (IPPSS) and the Zion Probabilistic Safety Study (ZPSS).
- 2. ' Work Performed During Period:
Comments on the final draft of the summary report on the ZPSS review have been received and are being factored into the final version of NUREG/CR-3300.
3.
Problems / Delays:
-None.
4.
Summary of Progress to Date/ Milestones:
No problem areas.
5.
Next Reporting Period:
Work will continue.
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l*EE RECOVER 1 COST STAfuS FIN:
A-371a 1(LE:
CONE nELT ACC.. INDIAN PT, ZION o
l'dd iou r JANUARY 1YO4
$ F ; ;:a 1 A:i,.(/ P L AN I P L:(l u u C, U r. u i.., ;.
H Task 4: Zion i Docket 50-2VS Tac 41ua4 1 a22.
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Monthly Business Letter Report A monthly business letter report will be submitted by the 20th of the' month to the NRR Project Manager with copies provided to the Director, Division of_ Systems Integration, ATTH:
S. Boyd, B. Sheron, DST and B. L. Grenier, NRR.
Tnese reports will identify the title of the project, the FIN, the Principal Investigator, the' period of performance, and the reporting period and will contain 3 sections as follows:
Project Status Section 1.
A listing of'the efforts completed during the period; mil.estones reached, or if missed, an explanation provided.
-2.
Any problems or delays encountered or anticipated and recommendations for resolution. 1/
3.
.A summary of progress'to date (this may be expressed in terms of percentage completion for the project).
4.
Plaris for the next reporting period.
Financial Status Section
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1.
Provide the total cost (value) of the project as reflected in the orcoosal (NRC Form 189), the total amount of fiinds coiicateTto date, anc tne balance of funds required to complete the work by fiscal year
-as follows:
Total Funds Balance of Funds Projected Obligated By Fiscal Year Project Cost To Date FY-FY -
FY-
' 2.-
Provide the total direct staff use and amount of funds' expended (costed) during the period and total cumulative to date in the follcwing categories:
Period Cumulative
.a.
Direct Lab Staff Effo'rt 5.
Funds (5000)
Direct Salaries Materials and Services (ExcludingADP)
ADP Support Subcontracts Travel Expenses Indirect Labor Costs Other (Specify)
General and Administrative TOTAL-( %) 2_/
-1/
If the recormiended resolution involves a Work Order modification.
i.e., change in work requirements, level of effort (costs), or period of performance, a seoarate letter should be prepared and submitted to the Director,' Division of Systems Integration, ATTN:
S. Boyd and a copy provided to the NRR Project Manager and B. L. Grenier, NRR.
1/
Drovide ' percentage against total funds oblicated to date.
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Fee Recovery Cost Status Section Pursuant to the provision of NRC Regulations,10 CFR 170, provide the total ancunt of funds expended (costed) during the period and cumulative to date
'for each task 3 the following fomat:
FIN: A3712 TITLE: Safety Evaluation of Core-Melt Accidents: Indian Point-0R and Zion OR Period:
Task I: Severe -Accident Progression Analysis: Reactor Systems / Containment Systems Loadings and Failure Modes Facility Docket #
TAC #
Period Cumulative Indian Point 2 50-247 466T5 Zion - 1 50-295 41044 Task II:
Radionuclide Release Assessment Facility Docket #
TAC 4 Period Cumulative Indian Point 2 50-247 48055 Zion 1 50-295 41044 Task III:
Consequence Analysis Facility Docket #
TAC #
Period Cumulative Indian Point 2 50-247 48055 Zion 1 50-295 41044
' Task IV: Risk Assessment Summary 9
Facility Docket #
TAC #
Period Cumulative Indian Point 2 50-247 48055 Zion 1 50-295 41044 Note:
If there is any effort under any of these tasks that is generic in nature such that the effort is required in order to peform the evaluation of any submittal, the cost for the generic effort should be prorated to each facility to which it applies.
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ACRS Review of the Zion PRA The ACRS is conducting a limited review of the Zicn Probability Safety Study with the aid of consultants. The primary intent of the review is to ascertain in an approximate fashion the general validity and/or the order of uncertainity in the conclusions and results of the Zion PRA. No technical areas are consciously excluded from the review; however, we will not attempt to system-natically cover all the important matters involved.
In this limited review, a considerable number of consultants will be asked to assist the ACRS in the areas of their expertise.
It is requested that each
. consultant identify the specific matters or areas on which he is inaking
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comments and express his individual opinions; however, an exchange of views or. a cooperative effort among some of the consultants in the process of conducting the review is encouraged.
v Some of the principal results from the Zion PRA are reproduced below in Table 11.2-1 from that study. The dominant contributors to risk were found to be 1.
Major seismic event (90%)
2.
Interfacing system large loca (5%)
3.
Loss of all AC Power and Auxiliary Feedwater (3%)
A major finding was that for the family of accidents estimated to be the significant contributors to core melt frequency, the vast majority of the core
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melt sequences do not result in containment failure, leading to a release
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either through the foundation or above ground level. This is a very important result which needs to be reviewed carefully.
Among the matters which arise in thisgegard 'are the following:
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Page Z Is the treatment of molten fuel with regard to its generation dispersal, interaction with water, attack on concrete, etc., valid?
Is the distribution of pressure vessel failure modes appropriate?
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Will the attack on the concrete by molten fuel be contained?
(In this regard, it is of interest to identify scenarios which, if they occurred, could lead to substantially different conclusions than
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those obtained in the Zion PRA).
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Will the quantities of hydrogen generated be as estimated and the effects of hydrogen burning have the relatively limited effects on containment integrity which are predicted? Are there matters such as equipment survivability or the vulnerability of containment penetrations which have not been addressed adequately?
Is the estimate of containment failure probability versus pressure reasonably valid? Does it allow adequately for flaws in construction /
fabrication?
Is the containment heat removal equipment as reliable as estimated for the circumstances? Would changes in the analysis of core melt phenomena
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influence such heat removal?
This is not intended to be a complete list of ques,tions, but is~ merely intended to develop one of the lines of thought which should be used in the review.
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A similar range of questions can be raised with regard to the likelihood of core melt scenarios.
In view of the low estimated likelihood of containnent failure /
large release of radioactivity, may other scenarios such as failure of the pressure vessel, become significant contributors?
Is the approach taken with regard to such other scenarios valid?
Has multiple (and possible inter-related) human error been treated-acceptably? Could an equally plausible choice of failure rates provide an order of magnitude difference in results? Are errors of commission included appropriately?
- - Has the Zion PRA allowed adequately for scenarios or failure modes not specifically identified by the use of the category "Other"?
Are design errors and construction errors included adequately? If not, how much change or uncertainity would be introduced by allowing for them?
Have all the potentially significant systems interactions been allowed for?
Is there any operating experience which goes counter to the results of the Zion PRA?
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Page 4' Does the seismic risk evaluation allow appropriately for uncertainities in earthquake probability and seismic fragility? Has the detailed plant behavior been approximated adequately for the purpose by the methods used here? Is enough known about the actual seismic design?
Is there a significant likelihood that a severe earthquake may not only cause a core melt accident but also directly cause a loss of containment integrity?
Does the evaluation of operator error for a severe earthquake have to be reconsidered in view of the potential for major losses of infor-mation in the control room (combined with failure or spurious behavior of much equipment with is not seismically qualified?
With regard to the calculation of off-site consequences, I will only pose a few questions at this time, as folllows:
Are the source terms reasonable?
Is the off-site evacuation plan treated acceptably? Is it acceptable in the case of a severe earthquake? Are the interdiction and decon-tamination approaches proposed practical for the actual areas involved?
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The questions faced above may not be the most important ones. Each consultant l
l is requested to judge for himself which matters should receive his attention.
In preparing a report on your evaluation, please include the following:
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the specific matters or areas you are dealing with, I
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Page 5, the important assumptions made in the Zion PRA in this regard, the implications of these assumptions, your conclusions about the general validity of the approach used and results obtained.
identification of specific issues or matters which appear to be
._._ subject either to significantly greater uncertainity or even a changed result, with reasons therefore, and t
identification of matters which may be important for reviewers of
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other sections of the report to consider.
i It is important to have a first round of comments from all ACRS Consultants by the end of January. These should be sent to:
Dr. David Okrent 5532 Boelter Hall Univ of California, Los Angeles Los Angeles, CA 90024 with a copy to:
Dr. J. Michael Griesmeyer Advisory Committee on Reactor Safeguards U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Around that time, the NRC Staff should have received a rough-cut review of the Zion PRA from its contractor, Brookhaven National Laboratory.
We hope to distribute i
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s Page 6, this to our consultants, together with a copy of the reports of our other consultsnts. We will ask each consultant if there are any additions or new evaluations to be made as a consequence of this iteration. After receiving the result of this secon: tep, we will probably hold a subcommittee meeting L
with the NRC Staff and their contractor, at which some of the ACRS consuktants would be asked to participate.
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