ML20096E574
| ML20096E574 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 05/12/1992 |
| From: | Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-011, IEB-88-11, NYN-92061, NUDOCS 9205190255 | |
| Download: ML20096E574 (5) | |
Text
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h Ted C. Feigenbaum President and Chief Exmutive Officer NYN-92061 May 12,1992 United States Nuclear Regulatory Commission Washington, D ;
20555 Attention:
Document Control Desk
References:
(a)
Facility Operating License No. NPF-86, Docket No. 50 443 (b)
NRC Bulletin 88-11, dated December 20,1988, "Pressuriter Surge Linc
' Thermal Stratification' Suoject:
Additional Respanse to NRC Bulletin 88-11: Pressurizer Surge Line Thermal Stratification Gentlemen:
NRC Bulletin 88-11 requested licensees to verify that the pressurizer surge line met Code design requirements and licensing commi:ments considering the effects of 'hermal stratification. The concern was that thermal stratification could result in high piping stress exceeding design limits for surge line stress and fatigue.
This letter summarizes the previous New Hampshire Yankee (NHY) responses to NRC Bulletin 8811, and confirms that NHY has completed all associated commitments. Earlier PSNH/NHY letters responding to NRC Bulletin 88-11 are listed in the Enclosure to this letter.
At the time of issuance of.Bulletin 88-11, NHY was awaiting issuance of the Low Powcr License for Seabrook Station. In letters dated March 7,1989 and April 10, 1989, NHY submitted a. qualitative evaluation and other information indicating that thermal stratification would not invalidate the existing stress analysis for the pressurizer surge line.
New Hampshire Yankee committed to perform a detailed, quantitative, plant-specific
- pre ssurizer surge line stress analysis including the effects of thermal stratification a nci striping. New Hampshire Yankee also committed to monitor surge line temperature and displacement for a limited time and provide the clata to Westingbouse if needed for use in the Westinghouse Owner's Group (WOG) surge line stratification generic progr;m. In an April 24,1989 letter, the NRC concluded that, with respect to this issue, Seabrook Station could operate at low power without undue risk to public health and safety, in 'a letter dated June 30, 1989, NHY submitted the results of the detailed, quantitative, plant-specific surge line stress analysis.
This analysis indicated that the pressurizer surge line' met the ASME Code design requirements without the need for modification. New Hampshire Yankee also committed to update the ASME Code,Section III, Class 1 Piping Stress Analysis for Seabrook Station to address pressurizer surge line stratification concerns.
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.se Division of Public Service Company of New Hampshire I
P.O. Box 300
- Seabrook, NH 03874 = Telephone (603) 474-9521
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-United States Nuclear Regulatory Commission May 12',1992
> ; Attention:
! Document Control Desk Page two l'
In~ an - October 24, 1989 letter, the NRC concluded that the Seabrook Station pressurizer surge line ruct applicable design requirements. In this letter, the NRC requested that surge line temperature and displacement data be' monitored until the first refueling outage. to. ensure that the design thermal transients and stratification temperature profiles used to verify code compliance were indeed bounding. In a letter dated December 1,1989, NHY committed to continue monit_oring the requested surge line parameters during the first operating cycle of.Seabrook Station.
In April _1990,- the - ASME Code, 'Section III, ' lass 1 Piping Stren Analysis for
- Sc orook Station was updated to address pressurizer s,..sa line stratification concerns.
l.
New Hampshire Yankee has reviewed the pressurizer surge line temperature and-displacement data _ collected during the. first operating cycle of Seabrook St2 tion and verified I
that this data-was enveloped by the thermal stratification design transients used in the tructural and fatigue ~ evaluation of the pressurizer surge line.
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L During this entire period, the WOG has provided the NRC with periodic status l_
' reports regarding the generic analysis of surge line stratification.
L Based on the above information, NHY has determined that the pressurizer surge line at ~Scabrook Station meets applicable design requirements, New Hampshire Yankee has completed all commitments associated with NRC Bulletin 8811, and believes that this issue can be considered closed. If you have any questions.on this matter, please contact Mr.
James:M. Peschel, Regulatory Compliance Manager at (603) 474-9521, Extension 3;72.
p-Very truly yours,
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' 'Unl4ed States Nuclear Regulatory Commission-May 12.1992 -
! Attention; JDocument Control-Desk Page three-
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' Mr. Thomas T. Martin Regional < Administrator U.S. Nuclear Regulatory Commission Region -I -
475 'Allendale Road.
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Mr. Gordon' E. Edison, Sr. Project Manager Project Directorate'_13 Division of Reactor Projects U.S.-' Nuclear Regulatory Commission Washington,- DC 20555 w
. Mr. Noel Dudley
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NRC Senior Resident Inspector
- P.O. Box"1149 Scabrook, NH ' 03874 ;
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' ENCLOSURE 1 TO NYN 92061 I.!ST OF PREVIOUS PSNH/NHY RESPONSES
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- TO NRC BULLETIN 88 i s
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E LIST OF PREVIOUS 'PSNil/NHY RESPONSES TO NRC BULI,ETIN 8811=
'(1)
PSNHI Letter _ NYN-88163 ' dated December 27,1988, " Interim Response to NRC.
Bulletin 88-11: Pressurizer Surge Line Thermal Stratification,"
G. S. Thomas to
.USNRC (2)
- PSNH Letter NYN 88164 dated December 30, 1988, ' Interim Response to NRC.
Sulletin. 88 11: Pressurizer Surge Line Thermal Stratification,"
G. S. Thomas to
.USNRC' (3)
= PSNH Letter NYN-89023 dated March 7,1989, " Response to NRC Bulletin 8811:
Pressurizer Surge Lbe Thermal Stratification,"
G. S. Thomas to USNRC (4)
NHY Letter _NYN-89037 dated April 10, _1989, " Response to NRC Bulletin 88-11:
Pressurizer Surge Line Thermal' Stratification,"
G. S. Thomas -to USNRC
_ (5) -.
NHY Letter NYN-89077 dated June 30,1989, " Follow-up Response to NRC Bulletin 88-11: Pressurizer _ Surge Line Thermal Stratification," T. C, Feigenbaum to. USNRC (6)i NHY Letter - NYN-89159 dated December 1,1989, " Additional Response to NRC Bulletin 88-11: Pressurizer Surge Line Thermal Stratification,"
T, C. Feigenbaum
_to USNRC it 1
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