ML12093A093
| ML12093A093 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim, EA-12050 |
| Issue date: | 04/02/2012 |
| From: | Bird R Boston Edison Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| SECY RAS | |
| References | |
| Commission-1, RAS 22182, EA-12-050 | |
| Download: ML12093A093 (3) | |
Text
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N P~lgrlm Nuclear b e r Stallon Rocky Hdl Road Plymouth. Masrarhuretts 02360 Ralph 6. Bird Senlor Vlce Presidenl - Nuclear U. S. Nuclear Regulatory Commission Document Contro! Desk Washington, DC. 20555 License DPR-35 Docket 50-293 REVISJILINFORMATION REGARDING PILGRIM STATION SAFETY ENHANCEMENT PROGRAM
Dear S i r :
Enclosed i s a description of a revised design f o r the D i r e c t Torus Vent System (DTVS) that was described i n the "Report on P i l g r i m Station Safety Enhancements" dated July 1. 1987 and transmitted t o the NRC with M r. Btrd's l e t t e r (BECo 87-11])
t o Mr. Varga dated July 8, 1987.
This revision supersedes I n i t s e n t i r e t y the Section 3.2 included i n the July 1. 1987 report.
On March 7. 1988 Boston Edison Company (BECo) personnel met r i t h Dr. Murley.
Mr. Russell, and Dr. Thadani and provided a tour o f SEP modiffcatlons and an informal presentation of the quantificatlon of competing r i s k s associated w i t h venting the containment and conclusions drawn from these results.
This presentation provided BECo the opportunity t o respond t o questions posed under Item 1 Section 3.2 - " I n s t a l l a t l o n of A D i r e c t Torus Vent System (DTVS)" i n Mr.
Varga's l e t t e r t o Mr. B i r d of August 21. 1987 " I n i t l a l Assessment o f P i l g r i m Safety Enhancement Program".
The materfal presented was made available t o the resident inspector and was included as Attachment I 1 i n NRC Inspection Report
- 88-12. dated May 31. 1988.
As you are aware from plant Inspections we have i n s t a l l e d the DTVS piping and portions o f related control wiring.
Currently, the DTVS I s isolated from the Standby Gas Treatment System (SBGTS) by b l l n d flanges I n s t a l l e d t n place o f Valve A04025 and the DTVS rupture disk.
This configuration was inspected by NRR i n the performance o f a technlcal review which focused on System.
Mechanical Design and Structural Design issues.
The review took place on March 2-3. 1988 as documented i n NRC Inspection Report #88-07. dated Hay 6. 1988 and determined the i n s t a l l a t l o n configuration t o be acceptable.
He now plan t o remove these b l i n d flanges and proceed ui t h i n s t a l l a t i o n o f Valve AD-5025 and t h e DlVS rupture disk.
We conclude the valve and rupture disk provide equivalent physlcal i s o l a t i o n of the DTVS piping from the SBGTS and appropriately ensure the operational i n t e g r i t y o f the SBGTS under design basis accident conditions.
Following completion of th!s work. ue w i l l perform a l o c a l leak rate t e s t t o v e r i f y that Valve A0-5025 i s acceptably leak t i g h t using the same method previously u t l l i z e d i n t e s t i n g the b l i n d flange.
Re a1 so plan t o complete a l l remainfng electrical work on the DTVS i n accordance w i t h the revfsed design.
Nov 14 05 ll:56a I /
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BOSTON EDISON W P August 18.
1 9 8 8
. U.S. Nuclear Regulatory Cormission Page 2 On the basis o f the revised Section 3.2, we conclude t h a t the DNS design as described i n the enclosure does not requlre any change to the Technical Speciffcations and t h a t we can proceed w i t h l n s t a l l a t t o n without p r l o r N R C '
approval.
please f e e l f r e e t o contact me o r Mr. J. E. Howard, of my s t a f f a t (617) 849-0900 i f you have any questions pertaining t o the design b e t a i l s o f the DTVS.
Attachment:
Section 3.2 Revlslon 1 Y I n s t a l l a t i o n Of A Direct Torus Vent System (DTVS)"
cc:
M r. 0. McDonald. Project Manager D i v i s i o n of Reactor Projects 1/11 O f f i c e o f Nuclear Reactor Regulation U. S. Nuclear Regulatory Comisslon Mall Statlon PI-137 Washington. D.C.
20555 U. 5. Nuclear Regulatory Comlsslon Region I 475 Allendale Road King o f Prussia. PA 19406 Senior NRC Resident Inspector P i l g r i m Nuclear Power Station