ML19332D292
| ML19332D292 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 11/22/1989 |
| From: | Trzyna G COMMONWEALTH EDISON CO. |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19332D293 | List: |
| References | |
| NUDOCS 8911300290 | |
| Download: ML19332D292 (2) | |
Text
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November 22, 1989 l
i Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Station P1-137 L
Washington DC, 20555 j
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Subject:
Zion Nuclear Power Station Unit 2 License No. OPR-48
+
NRC Docket No. 50-304 Analysis of Caosule Y-Unit 2 Reactor Vessel Gentlemen:
Enclosed are eight copies of the technical report which provides the-results of the Reactor Vessel Material Surveillance Program for Capsule Y for Zion, Unit 2, as required by 10 CFR 50 Appendix, H.
A summary of the report yielded the following results:
The capsule received an average fast neutron fluence (E > 1.0 MeV) of.1.48 x 1019 n/cm2 l
l Irradiatipn of the reactor vessel lower shell Plate C4007-1, to l
1.48 x 1019 n/cm, resulted in 30 and 50 ft-Ib transition temperature increases of 1210F and 1300F, respectively, for l
specimens oriented normal to the major working direction l
(transverse orientation) and temperature increases of 880F and 4
1030F, respectively, for specimens oriented parallel to the major. working direction (longitudinal orientation).
- Held metal irradiated to 1.48 x 1019 n/cm2 experienced increases in the 30 ft-lb and 50 ft-Ib transition temperatures of 2200F and 2550F, respectively.
This results in a 30 ft-lb l-transition temperature of 2100F and a 50 ft-lb transition temperature of 3000F.
Irradiation to 1.48 x 1019 n/cm2 resulted in no decrease in the average upper shelf energy of Plate C4007-1 (transverse orientation) and a decrease of 18 ft-lb for the weld metal.
This l
results in a weld metal average upper shelf energy of 51 ft-Ib.
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I L-Comparison of the 30 ft-lb transition temperature increases for the Zion Unit 2 survelliance material with predicted increases using the methods of NPI Regulatory Guide 1.99, Revision 2, demonstrated that the Plate C4007-1 material and weld metal transition temperature increases were 310F and 220F, respectively, greater than predicted.
NRC Regulatory Guide 1.99, Revision 2 requires a 2 sigma allowance, of 340F for base metal and 560F for weld metal, be added to the predicted reference transition temperature to obtain a conservative upper bound value.
Thus, the i
reference transition temperature incteases for Plate C4007-1 material and the weld metal are bounded by the 2 sigma allowance i
for shift prediction.
Please direct any further questions that you may have regarding this matter to this office.
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Very truly yours,
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Glenn E. Trzyna Nuclear 1.icensing Administrator j
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cc: Chandu Patel - NRR (w/ enclosure) l Senior Resident Inspector - Zion (w/o enclosure) i 1
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