ML18086A873
| ML18086A873 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/11/1981 |
| From: | Mittl R Public Service Enterprise Group |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| GL-81-14, NUDOCS 8108180155 | |
| Download: ML18086A873 (4) | |
Text
e 0 PS~G Public Service Electric and Gas Company 80 Park Plaza, T16D Newark, N.J. 07101 201/430-8217 Robert L. Mitt!
General Manager - Licensing and Environment August 11, 1981 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Attention:
Mr. Steven A. Varga,, Chief Operating Reactors Branch 1 Division of Licensing Gentlemen:
SEISMIC QUALIFICATION OF AUXILIARY FEEDWATER SYSTEM (GENERIC LETTER 81-14)
UNITS NO. 1 AND 2 SALEM NUCLEAR GENERATING STATION DOCKET NO. 50-272 AND 50-311 This letter transmits to you, in its enclosure, PSE&G's response to Generic Letter 81-14, "Seismic Qualification of Auxiliary Feedwater Systems".
Should you have any questions in this regard, do not hesi-tate to contact us.
Attach.
CC:
Mr. Leif Norrholm Senior Resident Inspector 1 a1oa1801.s5 a1oa11-*
PDR ADOCK 05000272 P
PDR The Energy Peopl8 Very truly yours,
SEISMIC QUALIFICATION OF AUXILIARY FEEDWATER SYSTEMS All the AFW system components and structures listed in Table l of the NRC Generic Letter 81-14 are quali-fied to withstand a Safe Shutdown Eathquake (SSE) utilizing analytical criteria consistent with other safety grade systems at Salem.
I.
MECHANICAL COMPONENTS (Primary water and supply path, piping, valves and pumps):
The Auxiliary Feedwater System at Salem No. l & 2 is designed in accordance with Seismic I Category requirements and the scope of seismic related NRC I&E Bulletins 79-02, 79-04, 79-07 and 79-14 have been included.
The Auxiliary Feedwater System at Salem No. l and 2 Units is designed to withstand a Safe Shutdown Earthquake (SSE).
Pipe stress analysis calcula-tions and supports have been analyzed within the limits of Safe Shutdown Earthquake requirements.
Seismic Methodology:
Seismic Analysis Method-ology for piping systems designated as Seismic Category I has been addressed in the Salem FSAR under Questions 4.14, 4.32, 5.35, 5.36, 5.37 and 5.50.
After the issuance of the NRC I&E Bulletin 79-07, a reanalysis of all Seismic Category I piping was performed combining individual earth-quake directional responses by the three dimen-sional square root sum of the squares method.
Acceptance Criteria:
Seismic Category I piping systems at Salem Nuclear Generating Station l & 2 have been designed to ANSI B31.l 1967 Code for Pressure Piping, including revisions and incor-poration of all summer and winter addenda up to the version of 1973 Code issuance.
Seismic Analysis Methods Employed:
Generally two methods were employed in performing seismic analysis for Category I piping response spectrum and simplified seismic analysis.
The criteria for selection between the two methods have been addressed in the Salem FSAR Question 5.50.
Furthermore, small bore, low temperature, Seismic Category I piping not analyzed by computers, utilized standard formulas, assuming known frequ-ency, to determine span lengths.
Seismic Input:
Pipe Stress analysis calculations for the entire Auxiliary Feedwater Systems have been performed utilizing Franklin Institute Re-search Center Piping Analysis Computer Program "PIPDYN II".
This program has been bench marked with other known commercially available Stress Analysis Computer Programs.
Seismic Input for category I piping is based on the guidelines established by the above program.
Load Combinations:
The loading combinations and the stress limits for Seismic Category I piping have been addresed in the Salem FSAR under Table C.4-2 in Appendix C, Amendment #16.
Allowable Stresses:
These limits have also been defined for the Seismic Category I piping in the Salem FSAR Table C.4-2.
As mentioned earlier in acceptance criteria, the stress limits meet the requirements'of ANSI B31.l Code for Pressure Pip-ing.
Engineering Evaluations:
Upon issuance of the NRC Bulletin 79-07 "Seismic Analysis of Safety Related Systems", a program was initiated to re-analyze piping systems based upon newer NRC re-quirements.
These analyses combined horizontal and vertical earthquake responses by the three dimensional square root sum of the squares met-hod.
Engineering reevaluations indicated that several pipe supports had to be modified as a re-sult of this NRC requirement.
This has since been accomplished and the necessary provisions and the conditions of the NRC issued Bulletins and Information Notices as referenced in the sub-ject Generic Letter have been fulfilled.
... -~.------ II.
ELECTRICAL AND CONTROLS COMPONENTS (Power supplies, initiation and control system, motors and actuators):
A detailed review of all electrical and controls equipment in the AFW system has shown that siesmic qualification has been achieved. All equipment desig-nated as Seismic Class 1 has been addressed in the Salem FSAR under question 7.18.
Further clarification is provided in the information provided by PSE&G to the NRC Seismic Qualification Review Team.
III. STRUCTURAL COMPONENTS (Structures supporting or housing AFW system):
The seismic analysis of* structures supporting or hous-ing AFW system was performed through lumped-mass model, time history analysis.
The translational and rotational accelerations of the supporting foundation computed by finite element soil-structural interaction analysis was used as input to the building.
Both OBE and SSE cases were analysed.
Seismic response spectra for qualification of equip-ment was generated from the horizontal and vertical time history acc.elerations calculated at each floor level of the Auxiliary Building.
The structural seis-mic design criteria at Salem are consistent with the NRC requirements.
The question of the failure of masonary wall (Con-trolled Facility Building damaging the AFW tank) aris-ing from the NRC Bulletin 80-11 has been addressed to the NRC.
[Letter dated July 2, 1980, from F. W. Sch-neider to B. H. Grier -
Unit l; letter dated September 5, 1980, from*R. L. Mittl to F. J. Miraglia-Unit 2].
The re,sponse is still under the NRC review.
MRD:mw AP6 1/4
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