ML20237G735

Forwards PLG-0550, Risk Mgt Actions to Assure Containment Effectiveness at Seabrook Station, Assessing Induced Steam Generator Tube Rupture & Direct Containment Heating Issues. Neither Issue Poses Threat to Containment Integrity

ML20237G735
Person / Time
Site:	Seabrook
Issue date:	08/10/1987
From:	George Thomas PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20237G738	List: ML20237G735 ML20237G749
References
NYN-87092, NUDOCS 8708140175
Download: ML20237G735 (4)

Text

'

George S. Thomas Vice President-Nuclear Production  !

J August 10, 1987 8

NYN- 87092 New Hampshire Yankee Division l

l l United States Nuclear Regulatory Commission

[ Washington, DC 20555 I

Attention: Document Control Desk

References:

(a) Facility Operating License NPF-56, Construction Permit CPPR-136, Docket Nos. 50-44 3 and 50-444 '

)

(b) PSNH Letter (NYN-87056), dated April 22, 1987, " Comments on Final Brookhaven National Laboratory Technical Eval-uation", George S. Thomas to the USNRC (c) PSNH Letter (NYN-87077), dated June 10, 1987, " Radio- )

logical Emergency Response Plan for Commonwealth of l Massachusetts, Request for Meeting", W. B. Derrickson i to Dr. T. E. Murley

Subject:

Assessment of Induced Steam Generator Tube Rupture (ISGTR) and Direct Containment Heating (PLG-0550)

Gentlemen:

In Reference (b) and during a meetin; with the NRC Staff and Brook-l haven National Laboratory on March 25, 1987, New Hampshire Yankee (NHY) I l committed to perf orm supplemental reviews of the Seabrook Station Risk Management and Emergency Planning Study to resolve technical areas iden-tified by the NRC Staff and the Brookhaven National Laboratory during i their assessment of the results and conclusions. In Reference (c), NHY indicated that such prior commitments to provide additional information l to the NRC would be kept, notwithstanding NHY's present intention not to resubmit a EPZ reduction waiver request. NHY believes that this addi-ti >nal information will be of value to the NRC in updating its under-standing of Seabrook Station's operation and safety. Accordingly, en-closed for your review please find a (etailed assessment (PLG-0550) of the Induced Steam Generator Tube nupture (ISGTR) and Direct Containment  ;

i Heating (DCH) phenomenological issues regarding the probability of early j Containment bypass and failure of the Seabrook Station Containment. Based on this study, NHY is convinced that neither issue poses a significant threat to containment integrity.

The enclosed report provides a significant level of detailed infor-mailon regarding these phenomenological issues. The probabilistic anal-ysis of Reactor Coolant System failure modes and Containment failure, including uncertainties, is included in the report. The ISGTR and DCH issues are re-examined in light of the results of this probabilistic analysis. These analyses include consideration of relevant results of NUREG-1150 and NUREG/CR-4896.

8708140175 870010 h

PDR ADOCK 05000443 k

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I p PDR s i P.O. Box 300 . Ssabrook, NH 03874 . Telephone (603) 474-9574

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United States Nuclear Regulatory Commission NYN- 87092 Attention: Document Control Desk Page 2 l

NHY is prepared to discuss this work with the NRC Staf f and respond to questions as appropriate. NHY requests that the Staff and its consultants review the study and provide us with any comments regarding the report's conclusions. Should you have any questions, please c.ntact Mr. W. J. Daley, Jr., at (603) 474-9521, extension 2057.

Very truly yours, cor .

[ v($l homas l

Enclosure I

cc: Atomic Safety and Licensing Board Service List (Offsite EP) l I

Mr. Victor Nerses, Acting Director PWR Project Directorate I-3 Division of Projects I/II U. S. Nuclear Regulatory Commission Washington, DC 20555 l

Mr. William T. Russell j Regional Administrator U. S. Nuclear Regulatory Commission Region I 631 Park Avenue ,

King of Prussia, PA 19406 I j

Mr. A. C. Cerne NRC Senior Resident Inspector Seabrook Station Seabrook, NH 03874 l

l

ASLB SERVICE LIST (OFF-SITE EP) i Helen Hoyt, Chairperson Senator Gordon J. Humphrey*

' Atomic Safety and Licensing Board Panel United States Senate U.S. Nuclear Regulatory Commission Washington, DC 20510 Washington, DC 20555 Attention: Tom Burack Gustave A. Linenberger, Jr. Richard A. Hampe, Esquire Atomic Safety and Licensing Board Panel Hampe and McNicholas U.S. Nuclear Regulatory Commission 35 Pleasant Street Washington, DC 20555 Concord, NH 03301 Dr. Jerry Harbour Thomas F. Powers, III Atomic Safety and Licensing Board Panel Town Manager j U.S. Nuclear Regulatory Commission Town of Exeter i Washington, DC 20555 10 Front Street Diane Curran, Esquire Andrea C. Ferster, Esquire Brentwood Board of Selectmen Harmon & Weiss RFD Dalton Road 2001 S Street, NW Brentwood, NH 03833 Suite 430 Washington, DC 20009 Peter S. Mathews, Mayor City Hall Sherwin E. Turk, Esquire Newburyport, MA 01950 Office of the Executive Legal Director i U.S. Nuclear Regulatory Commission Calvin A. Canney  !

Tenth Floor City Manager 7735 Old Georgetown Road City Hall Bethesda, MD 20814 126 Daniel Street .

Portsmouth, NH 03801 l Robert A. Backus, Esquire Backus, Meyer 6 Solomon Stephen E. Merril], Esquire i 116 Lowell Street Attorney General l P.O. Box 516 George Dana Bisbee, Esquire Manchester, NH 03105 Assistant Attorney General Office of the Attorney General Philip Ahrens, Esquire 25 Capitol Street Assistant Attorney General Concord, NH 03301-6397 l Office of The Attorney General Statehouse Station #6 Mr. J. P. Nadeau Augusta, ME 04333 Selectmen's Office 10 Central Road Mrs. Sandra Gavutis, Chairman Rye, NH 03870 j Board of Selectmen l RFD 1 - Box 1154 Mr. Angie Machiros, Chairman Kensington, NH 0382, Board of Selectmen Town of Newbury Carol S. Sneider, Esquire Newbury, MA 01950 Assistant Attorney General Office of the Attorney General One Ashburton Place, 19th Floor Boston, MA 02108 QLetter of transmittal only l

l

ASLB SERVICE LIST (OFF-SITE EP)

(Continued)

Mr. William S. Lord Board of Selectmen Town Hall - Friend Street Amesbury, MAL 01913 Senator Gordon J. Humphrey*  !

1 Eagle Square, Suite 507 Concord, NH 03301 Attention: Ilerb Boynton H. Joseph Flynn, Esquire Office of General Counsel Federal Emergency Management Agency l

500 C Street, SW Washington, DC 20472 (

l l

Paul McEachern, Esquire I Matthew T. Brock, Esquire Shaines & McEachern 25 Maplewood Avenue P.O. Box 360 Portsmouth, NH 03801 Gary W. Holmes, Esquire Holmes & Ells  !

47 Winnacunnet Road l Hampton, NH 03842 l  !

Mr. Edward A. Thomas FEMA, Region I  ;

442 John W. McCormack Post Office and Courthouse Boston, MA 02109 Robert Carrigg Town Office Atlantic Avenue North Hampton, NH 03862 Judith H. Mizner Silvergate, Gertner, Baker, Fine, Good & Mizner 88 Broad Street Boston, MA 02110 Charles P. Graham, Esquire McKay, Murphy and Graham 100 Main Street Amesbury, MA 01913 0 Letter of transmittal only

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