ML18095A771
| ML18095A771 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 02/28/1991 |
| From: | Labruna S Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-002, IEB-88-2, NLR-N91027, NUDOCS 9103070025 | |
| Download: ML18095A771 (4) | |
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Public Service Electric and Gas Company Pu-blic Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609~_339-4800 Vice President - Nuclear Operations
-FEB 2 8 1991 NLR-N91027*
United States Nuclear Regulatory* commission -
Document *control Desk Washington, DC 20555
-Gentlemen:
REVISION TO RESPONSE BULLETIN 88-02, RAPID PROPAGATING CRACKS IN S/G TUBES SALEM GENERATING STATION UNIT NO. _l
- DOCKET NOS. 50-272_ -
By letter dated Jamiary 19, 1990 (ref: NLR-N90019), Public
- service Electric & Gas Company(PSE&G) committed to plugging tube R9C60 in steam Generator 12.
This commitment was based on an evaluation of steam generator u bend viJ:>ration performed by Westinghouse, transmitted to PSE&G by letter, dated-January 10, _ 19_90 -(ref:PSE-90-507).
Re.cent -evaluation by Westinghouse_ has now concluded that the subject.tube need not be_plugged.
The analysis and reasoning.for the.new conclusion.has been provided to-PSE&G by Westinghouse
- letter dated January 24, 19_91 (ref: PSE~91-016)
- This letter is included as Attachment 1.
Based on the Westinghouse evaluation, PSE&G is _withdr~wing-its -
commitment to plug 'tube R9C60 iri steam generator 12.
Should there be any questions with regard to this submittal, please do not hesitate to contact: us~
Sin_cerely, Attachment 91 (_J:_.::.,_*17-,_-)(_"J.._';*C"._,
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Document control Desk NLR.:..:N9102'7
- c Mr. J. c. Stone
- Licensing Project Manager Mr. T. Johnson senior Resident Inspector 2
Mr. T. Martin, Administrator Region I Mr. Kent Tosch,. Chief New Jersey Department of Environmental.Protection Division of Environmental Quality Bureau of Nuclear Engineering
- CN415 Trenton, NJ 08625 '
FEB 2 e 1991
ro:
609 3313 1105
- JAN 241.1991 4:55p11
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BoX 355.
Westinghouse Electric Corporatrm Ene1V Systems PinsbtJrfl Pennsylvania 1 !1230-03!1!1
-Mr. H. G-. Barrick*
Project Manager Eng1neer1ng and Plant Betterment Public Servtce Electric & Gas Co.
P. o. Box 236 Hancocks*Bridge. ~J.* 08038
Dear Mr. Barrick:
PSE-91-016 January 24. 1991
. Ref: I) PSE-90*507 dated 1/10/90
- 2) PSE-90-738 dated 11/30/90
- PUBLIC SERVICE ELECTRIC AND GAS COMPANY SALEM UNIT 1 STEAM GENERATOR U-BEND TUBE VIBRATION EVALUATION This letter serves to update and clarify the preventive actions recommended for Salem Unit 1 with respect to U-bend vibration induced fatigue (North Anna R9C51 type tub~ ruptures).
In a previous transmittal (Reference l) 1t was recommended to PSE&G that one tube would require preventive action in order to preclude a potent1a1 tube rupture; This tube was located at R9C60 SG 2 in Unit l. Per the Westinghouse reconvnendat1on, PSE&G decided to install a cable tube damper fn this tube during the next scheduled outage.
{This outage has been scheduled to start during the first quarter of 1991.)
The AVB position evaluation performed in support of the conclusions described in Reference 1 has since been modified.
The modification has been performed in response to a request by the NRC to change the methodology of determining the depths of penetration of the AVBs.
The resultint change 1n AVB positions has produced a change in the flow peaking factors associated with some tubes.
The result of the updated
- study for Unit l indicated that no tubes would require preventive action to preclude a potential North Anna R9C51 type tube rupture for the operation conditions addressed in the original evaluation. Specifically, it was deteratntd that the tube identified earlier at R9C60 SG 2 of Unit 1 had a s1gnifteant reduction in the flow peaking factor and therefore wou1d not require.., preventive action. Th1s conclusion was transmitted to the utility 1n Reference 2.
The flow peaking factor was determined to be 1.48 in the previous evaluation while the flow peaking factor associated with the latest evaluation was determined to be 1.20. Comparing this to an allowable value of 1.37 1s a demonstration of the acceptability of this tube.
Subsequent to performing the original evaluation (results sunvnarized in Reference 1) it was determined that the plant is operating at a steam p~essu~e lower than the 000 ps1a steam pressure used 1n that evalunt~on.
TO~
609 339 1105 JAN 24. 19l3t
- 2 A
PSE-91-016 January 24, 1991 The plant 1-s 'currentl.)f operat-1ng at appro)(imately 765 ps1a. Thh produces a change 1n the U-bend vibration and fatigue response and could*
- potentially result 11f tubes that cou*ld become susceptible to a North Anna R9C51 type* tube r~p~*ure..,, l:he*re-evaluation performed*1n support of the increased steam generator tube plugging* study has -addressed both the effect* of operating Un1t *1 at*iower*steam pressures and tncreased steam generator -tube plugging (SGTP)*
This evaluation concluded that under the.
current conditions* no tubes would require plugging. 1n Un1t 1 for operation downto'730ps11.*
In sunvnary, it has been determined that no tubes will require preventive action to preclude a potential North Anna R9C51 type tube rupture 1n Salem Unit 1. Therefore; tube R9C60 SG 2 will not require stabilization, even
- if the steam generators cont f nue to operate at the current 1 ow steam pressure conditions, 1nclud1ng steam pressures (due to plugging) as low as 730 psia.
Please do not hes;tate to contact Sue Hauser (412-374-5108) if you have any questi-0ns or comments.
cc: D. N. Alexander M. F. Metcalf H. N. Trenka M. Danak
. Very truly y urs, J~ ~einmetz, C~n~al Area Customer Projects Department