ML20031E164
| ML20031E164 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 09/21/1981 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Counsil W NORTHEAST NUCLEAR ENERGY CO. |
| References | |
| NUDOCS 8110150162 | |
| Download: ML20031E164 (6) | |
Text
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DISTRIBUTION:
' Docket File TERA LB#1 RDG NRC/PDR SEP 211981 Huenton L/PDR DEisenhut NSIC BJYoungblood TIC JGrant ACRS (16)
MRushbrook RTedesco i
Docket No. 50-423 RVollmer TMurley RMattson RHartfield, MPA fir. W. G. Counsil 0 ELD Vice President Nuclear Engineering 0
-M and Operations li%7 Northeast Nuclear Energy Company e
,[f Nh Post Office Box 270 j
LU Hartford, Connecticut 06101 y
Dear Mr. Counsil:
OCT 1
- W
Subject:
Risk Evaluation - Millstone, Unit No.
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g' Due to high population densities and proposed power
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s -risk from certain nuclear facilities may represent a disproportionately high share of the total societal risk from potential reactor accidents. We have identified the Millstone 3 facility as a possibly above average site with respect to risk to the population within 30 miles. This judgement is based on the assumption that if the Reactor Safety Study (WASH-1400) reference plant were located at the Millstone 3 site, the societal risk from that plant would be higher than the societal risk from the WASH-1400 plant located at the WASH-1400 reference site.
Because of the importance of the specific plant design to the actual risk posed to the pub 1 R by a nuclecr power plant, we believe that a design-specific risk study should be performed by you and reviewed by the NRR staff prior to issuance of an operating license. The staff requests that you conduct the probabilistic risk assessment for the Millstone 3 facility using WASH-1400 type methodology. We recognize that the Millstone 3 facility design and site specifics are not identical to those of the WASH-1400 reference plant.
Therefore, you must take into account significant differences between the WASH-1400 plant and the Millstone 3 facility.
Dominant high risk accident sequences to be evaluated should be selected based on Millstone 3 plant-specific design con-siderations. Meterological, population, and hydrological data specific to the Millstone 3 site should be used in evaluating the consequences of selected accidents.
Your changes between the WASH-1400 plant and the Millstone 3 facility, including site specific data, should be defined in your evaluation.
We recognize that Northeast Utilities is participating in a pilot program, IREP, to develop a standardized methodology for performing PRA studies. We further
' recognize that under the joint leadership of IEEE and ANS, an industry-sponsored working group is responsible for developing a procedures guide by Spring 1982, 8110150162 810921 PDR ADOCK 05000423 A
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Mr. W. G. Counsil which would provide a reasonable structure for performing risk assessment on all operating plants under the National Reliability Evaluation Program, NREP.
However, because we cannot be sure that the procedures guide will be developed timely enough for your use, we request Northeast Utilities conduct this risk assessment study based on the currently existing methodology.
Various criticisms of the use of WASH-1400 should be recognized including those criticisms identified in the Risk Assessment Review Group Report to the U.S. Nuclear Regulatory Commission (Nt! REG /CR-0400). The purpose of the proposed Millstone 3 study is to evaluate the relative risk for the Hillstone 3 facility as compared to the risk identified with the WASH-1400 reference facility and site.
We request that you complete this evaluation and submit the results to us within six months from the time of FSAR docketing.
If you have any questions concerning the cbove, please contact the Millstone Unit No. 3 Project Manager, Jane Grant, at 301-492-7939.
Sincerely, Odelui SitwHF H. R. Deaten Harold R. Denton, Director Office of Nuclear Reactor Regulation
Enclosure:
As stated cc: See next page R_EWRITTEN IN HDENTON'S OFFICE - SEE PREVIOUS CONCURRENCES NR;hJ,R,
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9/.U./.81, suc row :. oo soisscu one OFFICIAL RECORD COPY
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Mr. W. G. Counsil Vice President Nuclear Cngineering and Operations Northeast Nuclear Energy Company Post Office Box 270 Hartford, Connecticut 06101 cc:
Mr. John J. Korkosz, Manager Mr. H. R. Nims, Manager City of Chicopee Electric Nuclear Products Light Department Northeast Utilities Service Company 725 Front Street Post Office Box 270 Chicopee, Massachusetts 01014 Hartford, Connecticut 06101 Mr. James E. Tribble Mr. Richard T. Laudenat, Manager Assistant to the President Generation Facilities Licensing New England Electric System Post Office Box 270 20 Turnpike Road Hart
>rd, Connecticut 06101 Westborough, Massachusetts 06508 Resident Inspector / Millstone NPS Mr. Bruce R. Garlick c/o U. S. NRC Manager, Energy Supply P. O. Draw.
KK Fitchburg Gas and Electric Niantic, Connecticut 06357 Light Company 655 Main Street Fitchburg, Massachusetts 01421 Mr. Wardman 4. Brooksbank, Manager Town of douth Hadley Electric Light Department 85 Main Street South Hadley, Massachusetts 01075 Mr. Ralph H. Wood General Counsel Public Service Company of New Hampshire 1000 Elm Street Manchester, New Hampshire 03101 William.H. Cuddy, Esq.
Day, Barry & Howard One Constitution Plaza Hartford, Connecticut 06103 Joen D. Fassett, Vice President The United Illuminating Company 80 Yemple Street New Javen, Connecticut 06508
~.. _..._._
E"Ct.05URE 2 Initiating Events _for Risk Study 1.
LOCA 2.
Transients 3.
Steam /feedwater line breaks 4.
Steam generator tube rupture
'5.
Failures during cold shutdown operation 6.
Fire 7.
- 8.
Explosions and missiles, internal and external
- 9.
Floods, tsunam'is' 10.
Tornadoes, hurricanes
- 11.
Massive electrical failure l
'Using best available methodology, consistent
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with IEEE/ANS effort.
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o ENCLOSURE 2
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Outline of Risk Study Report I.
INTRODUCTION II.
SUMMARY
1 III. METHODOLOGY OVERVIEW A.
Event trees B.
Fault trees C.
Quantification of accident sequences j
D.
Contcinment failure analyses E.
Fission product release analyses F.
Consequence analyses G.
Treatment of uncertainties IV. - SYSTEM DESCRIPTIONS 1
A.
Performance requirements B.
Actuation C.
Environnent considerations D;
Dependency diagrams for support systems - power, cooling, lubrication V.
CORE MELT PROBABILITIES
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A.
Dominant sequences B.
Dominant cut-sets VI.
FISSI0tl PRODUCT RELEASE ANALYSIS i
A.
Release groups B.
Containment failure probabilities C.
Fission project release fractions O
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CONSEQUENCE ANALYSIS A.
CCDFs, societal and individual B.
Dominant sequences for specific consequence categories VIII. COMPARIS0N WITH WASH 1400
'A.
Unique plant features, compared to the WASH-1400 reference plant B.
Modi *ications to the data base and data treatment, ccmpared to WASH-1400 C.
Assumptions regarding containment failure modes, compared to the WASH-1400 plant D.
Assumptions regarding operator actions and common mode failure, compared to WASH-1400 E.
Assumptions regarding decontamination factors, compared to WASH-1400 F.
Assumptions regarding metorology and evacuation, compared to WASH-1400 IX.
APPENDICES - DETAILS OF STUDY C
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Docket File bec:
LB#1 Rdg TERA HDenton NRC/PDR DEisenhut L/PDR Docket !!o. 50-423 BJYoungblood NSIC JGrant TIC MRushbrook ACRS (16)
Itr. W. G. Counsil RLTedesco Vice President !!uclear Engineering RVollmer and Operations TMurley iMtheast Nuclear Energy Company PsMattson Post Office Box 270 RHartfield, MPA Hartford, Connecticut 06101 OELD OIE (3)
Dear Mr. Counsil:
N Subj ect: PoiskNEvaluation - flillstone, Unit No. 3 N
Due to a combinatio'n of factors which include high population densities and s
proposed pomr levelsk the risk from certain nuclear facilities is believed to present a disproportionately high segment of the total societal risk from reactor accidents. Ne have identified the flillstone 3 facility as an above average site 3th respect to potential risk to the population within 30 niles. This judgement is based on the assumption that if the Reactor s
Safety Study (WASH -1400) reference plant were located at tF.e liillstone 3 site, the societal risk froa that plant would be higher ttan the societal risk from the WASH-1400 plant lo'cated at the WASH-1400 ref 6rence site.
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Because of the inportance of the shlecific plant design to the actual risk posed to the public by a nuclear power plant, we believe that a design-specific risk study should be perfomed by you'and reviemd by the NRR staff prior to issuance of an operating license. The staf f requests that you conduct the probabilistic risk assessment for the Hillstone 3 facility using the WASH-1400 s
nethodology. We recognize that the Millstone 3 facility design and site specifics are not identical to those of the NASH-1400 reference plant.
Therefore, you must take into account signiff' ant differences between the c
WASH-1400 plant and the Mill stone 3 facility. ' Dominant high risk accident sequences to be evaluated should be selected bas'd on tiillstone 3 plant-e specific design considerations. Meterological, po'pulation, and hydrological data specific to the 11111 stone 3 site should be used in evaluating the y
consequences of selected accidents. Your changes between the WASH-1400 s
plant and the Millstone 3 facility, including site specific data, should s
be defined in your evaluation.
N We recognize that Northeast Utilities is participating in a ilot program, IREP, to develop a standardized methodology for perfoming PRAsstudies. We further recognize that under the joint leadership of IEEE and A95 an g
industry-sponsored working group is responsible for developing a procedures guide by apring 1982, which would provide a reasonable structure forsperform-ing risk assessaents on all operating plants under the National Reliability Evaluation Program, NREP.
Howver, because we cannot be sure that the proce/ures guide will be developed timely enough for your use, we request tsortdeas t un iities conauct tnis rist a ssessrient stuay caseo or the exiscing
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~ Various criticisns of the use of WASil-1400 shou 11 be recognized including those criticisms identified in the Risk Assessment Review Group Report to the U.S. tiuclear Regulatory Comission (!1UREG/CR-04f)0), but since the purpose of the proposed !!illstone 3 study is to evaluate a relative risk for the Hillstone 3 facility as cmpared to the risk identified with the IfASil-1400
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reference facility, it is' believed that the use of WASH-1400 in this nanner is proper.
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!!e request that you complete thi_s evaluation and submit the results to us within six months from the time of FSAR dccketing.
If you have any questions concerning the above, please contact the Hillstone Unit No. 3 Project Manager, Jane Grant, at 301-492-7939.
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Si ncerely, y
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Harold R.\\Denton, Director Office of fluclear Reactor Regulation
Enclosure:
As stated cc: See next page
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