ML20128E077
| ML20128E077 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Seabrook |
| Issue date: | 07/17/1984 |
| From: | Cummings G, Ariuska Garcia LAWRENCE LIVERMORE NATIONAL LABORATORY |
| To: | Davis S Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19292B772 | List:
|
| References | |
| CON-FIN-A-0801, CON-FIN-A-801, FOIA-84-624 NUDOCS 8505290288 | |
| Download: ML20128E077 (5) | |
Text
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' i Lawrenca Livermoro National Laboratory i
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NUCLEAR SYSTEMS SAFETY PROGRAM July 17, 1984 SS-92-0351A-0037A Ms. Sarah M. Davis Reliability and Risk Assessment Branch-Division of Safety Technology U.S. Nuclear Regulatory Commission Washington, D.C.
20555
SUBJECT:
' Monthly Management Letter #2 Month of June 1984 NRC FIN-A0801 Review of the Seabrook Probabilistic Risk Assessment
Dear Ms. 0 avis:
1.
_ Project Description and Objective The Office of Nuclear' Reactor Regulation is conducting a probabilistic risk assessment (PRA) review program in which PRAs performed and submitted to the NRC by license applicants and licensees receive-comprehensive review and evaluation.' The program is the responsibility of the Reliability and Risk AssessmentBranch(RRAB).
A PRA of the Seabrook Nuclear Power Plant (Seab' rook PRA) has been submitted to the NRC by Public Service Company of New Hampshire,'an operating license (OL) applicant. The review of this document, whose title is "Seabrook Station Probabilistic Safety Assessment," is being performed as one project in the larger NRC program.
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The objective of this project is to perform an expeditious and cost effective review of those aspects of the Seabrook PRA leading to the estimates of the frequencies of each plant damage state and the associated uncertainty spread to determine the accuracy of these estimates. The review will cover methodology, assumptions, data, informat, ion sources, models, plant understanding, ' completeness of the analysis and other areas where inconsistencies may arise which could affect the quantitative or qualitative results.
2.
Progress for Period One copy of the FSAR, two copies of the P&lD's and two copies of the a.
PRA were received during the month, b.
One subcontractor (ARTECH) and one consultant (P. R. Davis) beoan work on the project.
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SS-92-0351A-0037A July 17, 1984
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The level of review effort increased during this month as we-c.
received additional documents and subcontractor and consultant l
agreements were established.
l 3.
Work to be Accomplished Next Month a.
Continue to increase the level of effort.
b.
.Make preparations for a site visit in late July, including the l,
development of questions for the utility on the PRA.
1 4.
List of Subcontractors and Consultants We are in the process of establishing, or have established subcontractor i
and consultant agreements with the subcontractors and consultants listed i
'below. We expect to add one or two additional names to this list -- for relatively small efforts in specialized areas.such as the evaluation of fire l
events.
l a.
Subcontractors (1) Applied Risk Technology Corporation (ARTECH); P. J. Amico (2) Jack R. Benjamin'and Associates, Inc.'(JBA); J. W. Reed, M. W. McCann, Jr.
b.
Consultants t
(1)
P. R. Davis S.'
Concerns Several problems have already been identified in the course of the review
.and as a consequence of planning the details of work yet to be done. Two are of particular importance since they have the potentia).for a significant adverse effect on the project schedule.
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L The first of these is a general recognition that the S-PRA will be far more difficult to review than was anticipated, due to a combination of the methodology used and what appears to bd a serious problem with scrutability.
The methodology used in the'PRA provides event tree models that are extremely large and complex.
In the internal events analysis, for example, the transient event tree has more than 5800 sequences for each support system entry state, and there can be as man'y as 40 of these entry states per initiator. An additional layer of complication is provided by the use of 36 plant damage states.
SS-92-0351A-0037A July 17, 1984 While the level of detail might be expected to m4ke the results easy to reproduce, we have so far been unable to reproduce the quantitative results in several areas that have been explored. An example is the calculation of the interfacingsystemLOCA(EventV).
We are also concerned that a plant visit has not yet been scheduled.
The original general plan for this review included a plant visit at about one month after the documents necessary for the review were received, and a target date of mid to late July was established. The importance of the plant visit should not be underestimated.
If it is delayed beyond the end of July, a corresponding delay for completion of the project will be necessary.
A third concern is the need for additional documentation for the review of the seismic portion of the S-PRA. We need a copy of the detailed calculations used to develop the structure and equipment fragilities for the plant, i.e., the " fragility calculations" that were performed by Structural.
Mechanics Associates, Inc. for use in the PRA.
6.
Other*
Not. Appi tcable.
s Mc
- Abel A. Garcia Princhal Investigator
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Garth E. Cummings j
Deputy Program Leader Nuclear Syste'ms Safety Program AAG:bmc Enclosures (2)
Olstribution NP.C 00E LLNL R. Frahm, OST W. J. Gallagher L. L. Cleland/G. E. Cummings J. Halvorsen, OST J. M. Johnson @
F. Rowsome, DST C. A. Meier, L. Solander, NRR
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A. C. Thadani, OST
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SS-90-0351A-0037A -
July 17, 1934 i
ATTACHMEQT A EST! MATED PROJECT FINANCIAL STATUS:
June.
FY 1964 FIN A0801 Summary COST ANALYS!S:*
June Year to Date t
~
Direct Staf f Ef fort 0.9 FTE-Mo
-0.1 FTE-Yr j
II Direct Labor Costs s
4.8K 4.SK Materials & Services 0.0 0.0 ADP Suppodt 0.0 0.0 Subcontracts 0.0 0.0 Travel 6:penses - -
O. A -
0.0 Indirect Labor Costs 4. "e
- 4. 5
- Other- (TID) 0.0 0.0 Other (LDL) 0.0 0.0 General & Admini'strative 0.0 0.0 Total ~ Costs 8
.9.3K 9.3K Liens 0.0K Tot'al Costs + Liens s
9.3K Percentage of Available Funds 13.0%
III Funding' Status i
Prior Year FY 1984 Frojected FY 1984 Funds FY 1984 Funding Cerryover Funding Leve!
Rec'd to Date Ba1. Needec s0.OK
$260.0K s75.OK t185.OK A N::, e Therto ftquees are for cost analysis only, and may differ slaghtly ir ct -4 a rial b2111ng f a 4 pres.
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SS-92-0351A-0037A July 17, 1984 ATTACHMENT B FEE RECOVERY COST STATUS FIN:
A0801 TITLE: Review of the Probabilistic Risk Assessment for the Seabrock Nuclear Power Plant PERIOD: June 1984 Docket' Costs Facility Name Number Period Cumulative Seabrook 50-443
$ 8.8K
$ 9K Common Costs 50-900 0.5
-1 Total Expenses 5 9.3K
$ 10K S
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S 6
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y 0
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s 0
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