ML18095A819
| ML18095A819 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 03/19/1991 |
| From: | Labruna S Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LCR-91-01, LCR-91-1, NLR-N91041, NUDOCS 9103270099 | |
| Download: ML18095A819 (3) | |
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Public Service Electric and Gas Company Stanley LaBruna Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1200 Vice President - Nuclear Operations MAR 1 9 1991 NLR-N91041 LCR 91-01 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
SUPPLEMENTAL INFORMATION MSIV CLOSURE TIME EXTENSION REQUEST FOR LICENSE.AMENDMENT SALEM GENERATING STATION UNIT NO. 1 FACILITY OPERATING LICENSE NO. DPR-70 DOCKET NO. 50-272 This letter revises information provided in support of PSE&G's application for an amendment to Appendix A to Facility Operating License DPR-70, Salem Generating Station Unit No. i.
The amendment request, dated February 1, 1991 (NLR-N91001), proposes to allow use of the eight second Main Steam Isolation Valve (MSIV) closure time during Salem Unit l's tenth cycle of operation.
MSIV Modification In support of the amendment request, PSE&G provided a description of actions planned to correct a water accumulation condition in the MSIV's, including a modification to the MSIV pressure equalization orifice and drain tube, in order to increase drainage capacity.
Subsequent to the February 1, 1991 letter, PSE&G performed additional work in order to optimize drainage capacity and *increase tolerance to vent valve leakage without adversely affecting valve closure.
The MSIV modification originally consisted of increasing the size of the pressure equalizing orifice from 0.0625 in. to 0.394 in., representing an increase in the through flow area of the piston. It also would have enlarged the drain tube holes from 0.125 in. to 0.196 in.
This modification was recommended by the valve manufacturer to increase the capacity to drain condensate from the MSIV.
PSE&G calculated that the recommended modification would result in an increased drainage capacity of 248 lbm/hr without vent valve leakage, compared to approximately 7.2 lbm/hr in the present configuration. It would also allow for a tolerance of approximately 240 lbm/hr of vent valve leakage before condensate would accumulate 1~ the MSIV vent chamber.
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NLR-N91041 MAR 1 9 1991 Document Control Desk In the previously described modification, the make-up rate of the equalizing orifice is the limiting parameter for drainage rate.
Therefore, PSE&G calculated the effects of further increasing orifice size in order to optimize the modification.
The revised modification consists of increasing the orifice size to
~ 0.449 in. (approximately 0.4409 in.), and leaving the drain tube hole size unchanged at 0.125 in.
The revised modification reallocates the increased area of the drain tube (from the original modification) to the area of the equalizing orifice, leaving the combined through flow area less than or equal to that of the modification described in the February 1, 1991 letter.
The revised modification results in a maximum drainage capacity of 205 lbm/hr (vs. 248 lbm/hr for the original modification),
which still far exceeds the maximum condensate generation rate of approximately 40 lbm/hr.
The reallocation of flow area to the orifice will increase the tolerable vent valve leakage to approximately 320 lbm/hr (vs. 240 lbm/hr for the original modification), without accumulating excess condensate within the vent chamber.
Therefore, this refinement optimizes the use of flow area by increasing vent valve leakage tolerance without adversely affecting the ability to remove condensate.
The revised modification has been reviewed and accepted by the valve manufacturer.
Post Modification Testing Following the MSIV modification, the surveillance test per Technical Specification 4.7.1.5 will be performed, with a five second stroke time acceptance criteria.
Upon successful completion of the normal surveillance test, a modified version will be performed.
The MSIV's will remain open in Mode 1 or 2 for approximately 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.
Each MSIV will be given an emergency closure signal, and its stroke time will be measured.
Acceptance of the modification will be based upon comparison of the two stroke times and visual observation of vent stack discharge.
This letter reflects an improvement to a modification which is part of the basis for the request presented in the February 1, 1991 amendment request. It also provides details regarding post-modification testing.
Therefore, PSE&G's Determination of No Significant Hazards Consideration, presented in the February 1, 1991 letter, remains valid.
- 9 NLR-N91041 MAR 1 9 1991 Document Control Desk Should you have any questions or comments on this transmittal, do not hesitate to contact us.
c Mr. J. c. stone Licensing Project Manager Mr. T. Johnson Senior Resident Inspector Sincerely, Mr. T. Martin, Administrator Region I Mr. Kent Tosch, Chief New Jersey Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625