ML13330B439
| ML13330B439 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/16/1988 |
| From: | Medford M SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| RTR-REGGD-01.099, RTR-REGGD-1.099 GL-88-11, NUDOCS 8812210265 | |
| Download: ML13330B439 (3) | |
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Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 M.O.MEDFORD TELEPHONE MANAGER OF December 16, 818) 302-1749 NUCLEAR REGULATORY AFFAIRS U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Response to NRC Generic Letter 88-11 San Onofre Nuclear Generating Station Unit 1 Generic Letter 88-11 requested a licensee technical analysis of the effects of neutron radiation on reactor vessel materials using Regulatory Guide 1.99, Revision 2, "Radiation Embrittlement of Reactor Vessel Materials."
The methodology provided in Regulatory Guide 1.99, Revision 2, which became effective May, 1988, would produce a more severe embrittlement prediction as a result of radiation exposure of reactor vessel beltline materials.
Licensees were further requested to submit a proposed schedule for completion of necessary actions, i.e., revisions to pressure-temperature (P-T) limits and low temperature overpressure protection (LTOP) requirements in the Technical Specifications and other hardware and operational modifications, to continue compliance with 10 CFR 50, Appendix G. It is the purpose of this letter to submit the results of the analysis done in accordance with RG 1.99, Revision 2, for San Onofre Nuclear Generating Station (SONGS), Unit 1.
The existing SONGS 1 P-T limits are based on the results of Westinghouse analysis WCAP-9520, "Analysis of Capsule F from the Southern California Edison Company, San Onofre Reactor Vessel Radiation Surveillance Program,"
dated May, 1979. This analysis was submitted for the NRC staff review in a letter from K. P. Baskin to H. R. Denton dated April 18, 1980, and was based on calculations of the temperature shifts due to the effects of radiation on the nil-ductility transition reference temperature, RTNDT, at 16 effective full power years (EFPY).
The limiting beltline materials were the intermediate shell plate W-7601-9 at the 1/4 thickness location and the lower shell plate W-7601-5 at the 3/4 thickness location.
The adjusted reference temperatures, ARTNDT, were 217oF and 1630 F, for 1/4 thickness and 3/4 thickness locations, respectively.
The results of the analysis done in accordance with RG 1.99, Rev. 2, for 16 EFPY of operation for all reactor vessel materials are enclosed. The resulting limiting reactor vessel beltline materials are intermediate shell 8812210265 881216 PDR ADOCK 05000206 P
FDC Li>
0 Document Control Desk December 16, 1988 plates W-7601-9 and W-7601-1 for 1/4 thickness location and W-7601-1 for 3/4 thickness location, respectively. The change in the limiting beltline material for 3/4 thickness location reflects the use of location specific fluences in evaluating the adjusted reference temperature. Since two credible surveillance data sets were available, the analysis was based on the Regulatory Position C.2.1 to determine the ARTNDT for 1/4 thickness and 3/4 thickness locations. They are 188.7 0F and 162.7 0F, respectively, which are bounded by the current Technical Specifications for SONGS 1. Therefore, no change in compliance with Appendix G of 10 CFR 50 is required.
If you have any questions regarding this matter, please call me.
Very truly yours, Enclosure cc: C. M. Trammell, NRR Project Manager, San Onofre Unit 1
- 3. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3
ENCLOSURE Predicted Values of Adjusted Reference Temperatures (ART) for SONGS 1 Reactor Vessel Beltline Materials at 16 EFPY Initial ID Surface 1/4 T 3/4 T Cu Ni(a) Rtial)
M(c) Fl I u aceP(
d) 1/TRT~n ART Flyence RTT ART Material
(
- 1)
R b)
) F19 ecm)
CFe)
(10 n/cm2)
(0FY Fn cm2)
(
Inter. Shell W7601-1 0.17 0.20 60 19.7 0.369 83.2 3.26 109.0 188.7 0.99 83.0 162.7 Inter. Shell W7601-8 0.18 0.20 40 19.7 0.369 87.0 3.26 114.0 173.7 1.00 86.7 146.4 Inter. Shell W7601-9 0.18 0.20 55 19.7 0.369 87.0 3.26 114.0 188.7 1.00 86.7 161.4 Upper Shell W7601-3 0.15 0.20 8
19.7 0.221 75.6 1.95 89.4 117.1 0.59 64.4 92.1 Upper Shell W7601-6 0.16 0.20 24 19.7 0.221 79.4 1.95 93.9 137.6 0.59 67.6 111.3 Upper Shell W7601-7 0.15 0.20 12 19.7 0.221 75.6 1.95 89.4 121.1 0.59 64.4
.96.1 Lower Shell W7601-2 0.17 0.20 34 19.7 0.111 83.2 0.98 82.4 136.1 0.30 55.7 109.4 Lower Shell W7601-4 0.14 0.20 51 19.7 0.111 70.9 0.98 70.2 140.9 0.30 47.5 118.2 Lower Shell W7601-5 0.14 0.20 82 19.7 0.111 70.9 0.98 70.2 171.9 0.30 47.5 149.2 Long Weld 7-860A -
0.27(a) 0.20
-56 59.0 0.300 125.1 2.65 157.7 160.7 0.81 117.7 120.7 Long Weld 7-8603 0.27(a) 0.20
-56 59.0 0.120 125.1 1.06 127.1 130.1 0.32 85.9 88.9 Long Weld 7-860C 0.27(a) 0.20
-56 59.0 0.0695 125.1 0.61 107.E 110.8 0.19 69.7 72.7 Long Weld 6-860A 0.27(a) 0.20
-56 59.0 0.072 125.1 0.63 185.0 188.0 0.19 69.7 72.7 Long Weld 6-8608 0.2 7(a) 0.20
-56 59.0.
0.0417 125.1 0.37 90.7 93.7 0.11 54.6 57.6 Long Weld 6-860C 0.2 7(a) 0.20
-56 59.0 0.130 125.1 1.59 179.7 182.7 0.48 99.5 102.5 Long Weld 8-860A 0.2 7(a) 0.20
-56 59.0 0.036 125.1 0.32 85.9 88.9 0.10 52.2 55.2 Long Weld 8-8603 0.27(a) 0.20
-56 59.0 0.0208 125.1
-0.18 68.1 71.1 0.06 40.4 43.4 Long Weld 8-860C 0.27(a) 0.20
-56 59.0 0.090 125.1 0.79 116.8 119.8 0.24 76.8 79.8 Circum. Weld 2-860 0.27(a) 0.20
-56 59.0 0.221 125.1 1.95 147.9 150.9 0.59 106.6 109.6 Circum. Weld 1-860 0.27(a) 0.20
-56 59.0 0.111 125.1 0.98 124.4 127.4 0.30 83.9i.
6.9 Ja)
Conservative estimate - no analysis available.
b Initial Reference Temperature measured or generic mean value per 10CFR 50.61 (b)(2)(i).
c) Margin to be added to cover uncertainties per Regulatory Guide 1.99 Rev. 2. Section 2.1 plates, or generic mean value margin for welds.
(d) Reference 6.
(e) Chemistry Factor determined per Regulatory Guide 1.99 Rev. 2, Section 2.1 using SONGS 1 surveillance data.