ML20247C239
| ML20247C239 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 05/17/1989 |
| From: | Loflin L CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLS-89-150, TAC-72854, TAC-72855, NUDOCS 8905240376 | |
| Download: ML20247C239 (4) | |
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Cp&L Carolina Power & Light Company.
MAY 171989 SERIAL: NLS-89-150 10CFR50.46 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-325 6 50-324/ LICENSE NOS. DPR-71 & DPR-62 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION SAFER /GESTR IDCA ANALYSIS (NRC TAC NOS. 72854 AND 72855)
Centlemen:
On April 10, 1989 and April 20, 1989, the NRC verbally requested additional information concerning Carolina Power & Light Company's March 29, 1989 submittal requesting permission to use the SAFER /GESTR-LOCA analysis methodology. A response to each of the questions is provided in the enclosure to this submittal.
Please' refer any questions regarding this submittal to Mr. Stephen D.
Floyd at-(919) 546-6901.
Yours very truly, f
Leonard I. Loflin Manager Nuclear Licensing Section BAB/bab
(\\cor\\ safer)
Enclosure cc:
Mr. S. D. Ebneter Mr. W. H. Ruland Mr. E. G. Tourigny 8905240376 890517 PDR ADOCK 05000324 P
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ENCLOSURE l
BRUNSWICK STEAM ELECTIRC PLANT, UNITS 1 AND 2 NRC DOCKETS 50-325 & 50 324 OPERATING LICENSES DPR-71 6 DPR-62 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION SAFER /GESTR-LOCA ANALYSIS (NRC TAC NOS. 72854 AND 72855)
NRC OUESTION 1 Confirm that plant specific operating paraesters have been bounded by the models and inputs used in the generic calculations.
GE6L RESPONSE The BSEP specific operating parameters and inputs have been conservatively bounded by the models and inputs used in the generic calculations.
Although this statement is not explicitly made in the SAFER /GESTR report, it is implicit in the discussions in Sections 3.2-1 (Page 3-2) and 5.2 (Page 5-4).
NRC OUESTION 2 Relative to relaxation of input values (Table A1), what are all of the relaxations between the new analysis and the analysis of record (i.e.,
the current analysis)?
CP&L RESPONSE Parameter relaxations for the new SAFER /GESTR analysis are described on Pages 4-1 and 4-2 of the SAFER /GESTR report. Table Al of the report simply summarizes the ECCS parameter relaxations considered in the sensitivity studies (Page 4-2) and is not intended to be a summary of all ECCS parameter relaxations incorporated in the SAFER /GESTR analysis.
Key differences between the SAFER /CESTR analysis and the analysis of record are summarized in the attached table.
NRC OUESTION 3 On Page 4-2, third paragraph, HPCI is assumed not to be available.
Table 4-3, Single Failures, appears to take credit for HPCI availability.
Please explain this.
CP&L RESPONSE Table 4-3 lists the remaining ECC systems resulting from the indicated break / single failure combination. For several break / single failure combinations, the HPCI system would be available. However, the BSEP SAFER /GESTR-LOCA analysis conservatively assumes that the HPCI system does not function and no coolant flow is delivered to the vessel (i.e.,
it is " unavailable"). This assumption was made to facilitate future l
HPCI system parameter relaxations.
1 NRC OUESTION 4 On Page 3-2, second paragraph, the BSEP ECCS configuration for suction breaks is compared to the generic BWR 3/4 ECCS configuration. How does the BSEP ECCS configuration for discharge breaks compare with the generic BUR 3/4 ECCS configuration?
CP&L RESPONSE For a discharge break with a DC power failure, the ECC systems remaining for the generic BWR 3/4 include one low pressure core spray (LPCS) system and one low pressure coolant injection (LPCI) system.
The dual unit BSEP has two potentially limiting DC power failures. One failure, termed DC Power (i), results in one LPCS and one LPCI remaining on the affected unit.
The other failure, DC Power (j), has two LPCS systems remaining (see Table 4-3).
Since the case with one LPCS and one LPCI remaining is more limiting than the case with two LPCS systems remaining, the limiting BSEP ECCS configuration for discharge breaks is conservatively bounded by the generic analysis, j
NRC O'UESTION 5 In reference to Question 3, is HPCI available for other (non-LOCA) transients?
CP&L RESPONSE HPCI is available for non-iDCA transients.
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i TABLE 1
KEY LOCA ANALYSIS DIFFERENCES ITEM ANALYSIS OF RECORD NEW ANALYSIS Methodology SAFE /REFLOOD SAFER /GESTR Core Thermal Power (MWth / % rated)
Nominal N/A 2680/110 1
Appendix K 2531/103.9 2733/112.2 D/G Start Time 10 seconds 15 seconds LPCI IV Stroke Time 28.5 seconds 38,5 seconds LPCI Pump Start Time 12 seconds 38.5 seconds Discharge Valve Stroke Time 33 Seconds 38 seconds LPCS IV Stroke Time 12 seconds 15 seconds LPCS Pump Start Time 17 seconds 25 seconds LPCS Pump Rated Flow 4725 GPM 4100 gpm LPCS Pump Rated Flow (1 pump in 1 loop) 10300 gpm 9000 gpm HPCI Pump Minimum Flow 4250 gpm 0 gpm MSIV Closure Stroke Time 10 seconds 15 seconds l
Number of SRV/ ADS Valves with ADS Function 7
5 SRV Setpoint Tolerance
+1%
+3%
I 1
2531 MWth corresponds to 105% steam flow and conservatively exceeds the Appendix K requirement of 102% of nominal thermal power.
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