ML20035C316
| ML20035C316 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 03/29/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20034D444 | List: |
| References | |
| SAIC-92-6657, NUDOCS 9304070045 | |
| Download: ML20035C316 (3) | |
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'l UNITED STATES Enclosure 3.. I E
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RE0 VESTS FOR DEVIATION FROM CERTA 10 FIRE PROTECTION PROVISIONS OF APPENDIX R TO 10 CFR PART 50 SUS 00EHANNA STEAM ELECTRIC STATION. UNITS 1 AND 2 DOCKET NO. 50-387 AND 50-388 i
1.0 INTRODUCTION
By letter dated December 29, 1989, Pennsylvania Power and Light Company (PP&L or licensee) submitted Revision 4 to the Susquehanna Steam Electric Station (SSES), Units 1 and 2 Fire Protection Review Report (FPRR).
The submittal was supplemented by the licensee's response of August 29, 1991, to the NRC staff's request of July 30, 1991, for additional information.
The licensee's submittal was reviewed for NRC by Science Applications International Corporation (SAIC). SAIC submitted their evaluation (Technical i
Evaluation Report, SAIC-92/6657 dated July 22, 1992) of the various PP&'.
documents.
We have reviewed the SAIC Technical Evaluation Report (TER) and agree with the details of their evaluations and conclusions.
The SAIC TER is attached to and is a part of this safety evaluation.
2.0 EVALUATION 2.1 Summary of TER By way of recapitulation, the significant conclusions from the SAIC TER are summarized below:
2.1.1 The changes to Section 3.3.1 on PP&L's position on fire induced transients relative to Appendix R safe shutdown methodology is acceptable.
2.1.2 Section 3.3.1.5 was revised to include a description of the analyses performed on multiple high impedance faults.
The analyses were based on the guidance in NRC Generic Letter 86-10.
In response to the staff's request for additional information, PP&L provided with their letter of August 29, 1991, a 500-page report prepared by Stone and Webster Engineering Corporation on the Appendix R Multiple High Impedance Fault Analysis. As discussed in the TER, SAIC determined that the calculations fully supported the licensee's conclusion that no multiple high impedance fault concerns exist for safe shutdown fuses at SSES, Units 1 and 2.
9304070045 930329 PDR ADOCK 05000387 F
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2.1.3 The revisions to Section 4.5 describing the activation capabilities for plant deluge systems is acceptable.
i 2.1.4 The revisions to various sections to add the Appendix R Voice Powered-Communication System used for post fire safe shutdown'are acceptable.
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2.1.5 The clarifications, corrections and updating to various Sections as described in the licensee's letter of December 29, 1989, are acceptable.
2.1.6 The revisions to Deviation Request Nos. 4, 9, 12, 13, 15, 16, 21, 24, l
25, 26, 27, 28 and 30 are acceptable.
2.1.7 New Deviation Request No. 38 is acceptable as discussed in the TER.
l 2.2 Deviation Reauests 39 and 40 As stated in the attached TER, the contractor did not evaluate Deviation f
Requests Nos. 39 and 40 because the staff wanted to assess these two requests.
l Deviation Request No. 39 pertains to 16 redundant drywell pressure switches j
which are spatially separated by a minimum of 140 feet in Unit I and 115 feet in Unit 2.
Automatic fire detection is provided in both fire zones 1-60 i
and 2-6D but not automatic fire suppression.
Part 50 of 10 CFR Appendix R, 7
Section III.G.2.b requires a minimum of 20 feet separation of redundant safe shutdown cables and equipment with no intervening combustibles and the presence of fire detection and automatic suppression.
The deviation is requested from Section'III.G.2.b of Appendix R in that no automatic' suppression is provided and intervening combustibles are present. Deviation Request No. 40 pertained to safe shutdown raceways in an equipment access area j
in a normally locked radiation area.
Deviation Requests Nos. 39 and 40 are being evaluated as a separate action in l
conjunction with the staff's assessment of fire barrier materials.
i 2.3 Safe Shutdown i
Our letter of August 9,1989, approved Revision 3 to the Susquehanna FPRR.
The staff found that the licensee's fire protection program, safe shutdown analysis and the schedule for completion of certain modifications (which were subsequently completed at the next refueling outages) to be acceptable.
However, there was one issue in the licensee's Safe Shutdown Analysis -
l specifically, the evaluation of high impedance faults - which, at the time, the staff concluded had not been adequately addressed. As discussed previously, with their response of August 29, 1991, to our request for i
additional information, PP&L submitted a 500 page report prepared by Stone and Webster Engineering Corporation on the Appendix R Multiple High Impedance Fault Analysis, which, as discussed in the TER, was reviewed by the contractor and found acceptable. With this determination, the staff has concluded that the licensee's safe shutdown analysis, as submitted with Revision 3 of the FPRR on June 30, 1988, is acceptable.
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i i During the week of December 5-9, 1988, the NRC conducted a team inspection of.
the safe shutdown capability of SSES, Units 1 and 2.
The team included two specialists from Brookhaven National Laboratories (BNL).
The results of the inspection were reported in Inspection P.eports Nos. 50-387/88-21 and 50-388/88 issued January 26, 1989. The inspectors cuncluded that.the-licensee complied with the requirements of 10 CFR 50.48 and 10 CFR 50 Appendix R, Section Ill.G and J with respect to safe shutdown capability.
However, there were 'several unresolved and open items. One of the open items was that NRR had not completed an evaluation of the licensee's analysis of high impedance faults (pages 10 and 11 of report). The issuance of this safety evaluation closes out this item.
2.4 Summary i
2.4.1 Revision 4 to the Susquehanna FPRR is approved.
2.4.2 The changes to the Deviation Requests submitted by PP&L's letter of December 29, 1989, are approved.
2.4.3 New Deviation Request 38 is approved.
2.4.4 PP&L's Safe Shutdown Analysis submitted by letter dated June 30, 1988, is approved.
2.4.5 New Deviation Requests Nos. 39 and 40 will be evaluated as a separate action.
Principal Contributor:
R. Clark Date:
March 29, 1993 5
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