ML13324A816
| ML13324A816 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/17/1986 |
| From: | Medford M Southern California Edison Co |
| To: | Lear G Office of Nuclear Reactor Regulation |
| References | |
| TAC-55027 NUDOCS 8603190042 | |
| Download: ML13324A816 (4) | |
Text
Southern California Edison Company P. 0.
BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M.O.MEDFORD TELEPHONE MANAGER. NUCLEAR LICENSING 18181 302.1749 March 17, 1986 Director, Office of Nuclear Reactor Regulation Attention:
G. E. Lear, Director PWR Project Directorate No. 1 U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Heatup and Cooldown Curves San Onofre Nuclear Generating Station Unit 1
References:
A. Letter, Kenneth P. Baskin, SCE, to H. R. Denton, NRC, dated May 17, 1984 B. Letter, John A. Zwolinski, NRC, to Kenneth P. Baskin, SCE, dated January 31, 1985 C. Letter, K. P. Baskin, SCE, to H. R. Denton, NRC, dated April 18, 1980 Reference A enclosed SCE Amendment Application No. 118 to revise the Heatup and Cooldown Curves for San Onofre Unit 1. An evaluation of Proposed Change No. 137, enclosed with Application No. 118 was provided via Reference B. The evaluation concluded that results of analysis of Capsule F confirm that the pressure-temperature limits provide sufficient margin to account for neutron irradiation damage through 16 EFPY of operation. However, that evaluation also concluded that further information was required to confirm the safety margins for the closure flange region. Rather than perform the necessary analysis to demonstrate that the closure flange region is not the limiting region for determining the slopes of the heatup and cooldown curves, and because editing the curves to take advantage of the provisions of the current 10 CFR 50 Appendix G for the closure flange region will not affect plant operation, we have decided to modify the curves.
The revised curves are provided as an enclosure.
It should be noted that the analysis submitted via the Reference C letter was based on Appendix G to Section III of the ASME B & PV Code which was in effect prior to the current version of 10 CFR 50 Appendix G. The current revision of 10 CFR 50 Appendix G became effective on July 26, 1983.
8603190042 860317 PDR ADOCK 05000206 P
e Mr. G.
March 17, 1986 These curves should resolve the concerns with the margins associated with the closure flange region and therefore the additional information requested in Enclosure 2 to the Reference B letter is not necessary.
If you have any questions, please contact me.
Very truly ours, Enclosure
Enclosure 4000 MATERIAL PROPERTY BASIS AT I/4T LOCATION CONTROLLING MATERIAL:
INTERMEDIATE SHELL COPPER CONTENT: 0.18 WT PHOSPHORUS CONTENT: 0.014 WT RTNDT INITIAL: 550F RTNDT AFTER 16 EFPY,: 217oF MATERIAL PROPERTY BASIS AT 3/4T LOCATIO0N CONTROLLING MATERIAL:
LOWER SHELL COPPER CONTENT: 0.14 WT-F' PHOSPHORUS CONTENT: 0.014 3000 RTNo INITIAL: 82oF Ti RNDT AFTER 16 EFPY: 163oF T-1 CURVE APPLICABLE FOR HEATUP RATES UP TO 60oF/HR FOR THE SERV ICE PERID UP TO 16 EFPY AND CONTAINS MARGINS OF 10oF AND 60 PSIG FOR POSSIBL E.
T, INSTRUMENT ERRORS 2000 II L EAK TEST LIMIT LU Region modified to IIt account for closure IIIL flange region per IIIL A pendix G to 10 CFR 50 CRITICALITY ILIMIT RATES HYDROSTATIC TEST 60 0
0 100 200 300 400 500 INDICATED TEMPERATURE (OF)
FIGURE 3.1.3a San Onofre Unit No. 1 Reactor Coolant System Heatup Limitations Applicable for the First 16 EFPY.
3000 MATERIAL PROPERTY BASIS CONTROLLING MATERIAL:
INTERMEDIATE SHELL COPPER CONTENT: 0.18 WT' PHOSPHORUS CONTENT: 0.014 WT' RTNDT INITIAL: 550F RTNDT AFTER 16 EFPY: 1/4T. 21 70F CURVE APPLICABLE FOR COOLDOWN RATES UP TO 100oF/HR FOR THE SERVICE PERIOD UP TO 16 EFPY AND CONTAINS MARGINS OR 100 F AND 60 PSIG FOR POSSIBLE INSTRUMENT ERRORS.
2-2000 a-,
LU Region raodified to C.-
account for closure
.flange region per 1000
_Appendix G to 10 CFR 50
-COOLDOWN RATE OF/HR 0
20 orv 40 60
-100 0
I I 1 I 0
100 200 300 400 500 INDICATED TEMPERATURE (OF)
FIGURE 3.1.3b San Onofre Unit No. 1 Reactor Coolant System Cooldown Limitations Applicable for the First 16 EFPY.