ML17219A652
| ML17219A652 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 06/23/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17219A651 | List: |
| References | |
| TAC-64081, NUDOCS 8706300153 | |
| Download: ML17219A652 (11) | |
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ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO APPENDIX H
SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULE FLORIDA POWER AND LIGHT COMPANY ST.
LUCIE PLANT UNIT 2 TAC NO.
64081 DOCKET NO. 50-389
- 1. 0 BACKGROUND At the time of licensing, the staff evaluation of the materials surveillance program (Appendix H, 10 CFR 50), to be conducted by Florida Power and Light Company (FPL) for St.
Lucie Unit 2, was reported in Section 5.3. 1.3 of
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NUREG-0843, October 1981 (Reference 1).
The evaluation, repeated herein in its entirety, is:
"The toughness properties of the reactor vessel beltline materials will be monitored throughout the service life of St.
Lucie, Unit 2, by a materials surveillance program that must meet the requirements of Appendix H, 10 CFR Part 50.
Based on our review of the applicant's submittal that described that extent of compliance of St. Lucie, Unit 2, with Appendix H, 10 CFR Part 50, we have determined that the requirements of Appendix H have been met and that the reactor vessel material surveillance program is acceptable.
We wi 11 reevaluate the surveillance program after the mechanical test data from the material in the first surveillance capsule are submitted for review."
8706300k 53 870623 PDR ADQCK 05000389,L P
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By letter dated November 5, 1985 (Reference 2),
FPL submitted the results of the examination of the first surveillance capsule removed from St.
- Lucie, Unit 2.
The results are contained in the attachment to the letter.
Both the examination and the report are the effort of Babcock and Wilcox (B8M).
By letter dated July 15, 1986 (Reference 3),
FPL proposed a license amend-ment regarding reactor vessel pressure temperature (P-T) limits (Appendix G, 10 CFR 50) and a new Low Temperature Overpressure Protection (LTOP) analysis
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results.
The staff. requested additional 'information regarding the proposed P-T limit changes to the Technical Specification to which FPL responded by letter dated September 4, 1986 (Reference 4).
During the review of this information the staff noted that the capsule withdrawal schedule contained in the St.
Lucie, Unit 2, Technical Specifica-tions.as Table 4.4-5 specified the removal of only 3 capsules over the life of the plant.
Based on the information available to the staff, there should have been 5 capsules scheduled for withdrawal.
In the safety evaluation forwarded to FPL on August 7, 1986, the staff requested FPL provide a justi-fication for the St.
Lucie Unit 2 reactor pressure vessel surveillance capsule withdrawal schedule or commit to the withdrawal schedule contained in the safety evaluation.
By letter dated December 2,
1986 (Reference 5),
FPL provided justification for the scheduled withdrawal of 3 capsules, that is, the capsule withdrawal schedule contained in Table 4.4-5 of the St.
Lucie, Unit 2, Technical Specifications.
Subsequently, on January 30, 1987 the bases'for the number of capsules and the withdrawal schedule was discussed in a conference call between the licensee and the staff.
By letter dated April 1, 1987 (Reference 6), the licensee stated what action would be taken.
In a letter dated May 17, 1987 (Reference 7),
the licensee provided a revised neutron fluence vs. transition tempera-ture shift figure to be used in place of the present Figure B 3/4.4-1 in the Technical Specifications.
- 2. 0 TECHNICAL REVIEW CONSIDERATIONS Given the requirements of Appendix H of 10 CFR 50 and the information in References 1 through 7, the appropriate number of capsules and associated withdrawal schedules for the reactor vessel material surveillance program at St. Lucie, Unit 2 can be determined.
When the licensee submitted the first.surveillance capsule report (Reference 2), the transmittal letter contained no changes to the reactor vessel material surveillance pro-gram at St.
Lucie, Unit 2.
In this evaluation of the data in Reference 2,
the staff concludes that 'five capsules should be scheduled for withdrawal.
The justification by the licensee for the three capsules presently scheduled for withdrawal is contained in References 5 through 7.
As a result of discussions between the staff and the licensee, the licensee concluded that Bases Figure B 3/4.4-1 in the Technical Specification needed revising in order to substantiate the present number of capsules scheduled for withdrawal.
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- 3. 0 EVALUATION The bases for the review is founded in Appendix H of 10 CFR 50 which refers to ASTM E 185-82, Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels.
In Reference 5,
FPL claims that the materials surveillance program for St.
Lucie, Unit 2, is consistent with the objectives of ASTM E 185-82 and Appendix H of 10 CFR 50.
Based on the present Figure B
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Technical Specifications, the staff disagreed with this 3/4.4-1 in the claim, speci-fically with regard to the number of capsules scheduled for withdrawal and the schedule for withdrawal.
The minimum number of capsules and their schedule of withdrawal is governed by Table 1 of ASTM E 185-82.
The determination is based on the predicted transition temperature shift, ARTNDT at the vessel inside surface.
In Table 1 there are three discrete sets of minimum number of capsules and associated withdrawal sequence, one set for LLRTNpT 1 ess than or equal to 100 F, one set for hRTNDT 1 ess than or equal to 200 F, and one set for ART greater than 200'F.
Figure B 3/4.4-1 in the Technical Specifications for St.
Lucie, Unit 2, specifically gives the expected transition temperature shift in degrees Fahrenheit as a function of the neutron fluence (E>l MeV).
The solid
line'in this figure bounds the triangular points.
The precision associated with the ability to read the fig'ure is between 5 and 10 Fahrenheit degrees.
The appropriate neutron fluence to be used is that at end of license (EOL) or 32 effective full power years (EFPY).
From Table 6-3 of Reference 2, the projected inside surface fast fluence at the end of 32 EFPY is 3. 64 x 10'/cm (E>1 MeV).
From Table 6-5 of Reference 2, the estimated fluence uncertainty for the vessel at 32 EFPY is a 30K plus undefined uncertainty due to future cycles.
Thus, to con-servatively predict the fluence at 32 EFPY one must add 30K or 1.09 x 10 n/cm (E>1 MeV) to 3.64 x 10 n/cm (E>1 MeV) which yields 4.73 x 10~s n/cm~ (E>l MeV).
Using this value of fast fluence, the RTNpT transition temperature shi ft is 225 F as determined from Figure B 3/4.4-1.
However, the licensee indicates a revised figure for transition tempera-ture shift versus neutron fluence using the data point from Reference 2
would be more specific to St.
Lucie 2.
The current figure in the Techni-cal Specifications was constructed from the best available data at the time of licensing.
Reference 7 contains a revise'd neutron fluence versus transition temperature shift curve based on Regulatory Guide 1.99, Revision 2, methodology and St.
Lucie 2 specific reactor vessel material properties.
Using this figure the transition temperature shift at end of license is much less than 200 F, approximately 128'F.
From Table 1 of
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"6-ASTM E 185-82, the minimum number of capsules scheduled for withdrawal, when BRTNDT is less than 200'F, is 3.
Table 4.4-5 of the present Technical Specifications for St.
- Lucie, Unit 2, shows 3 capsules. scheduled for withdrawal, one at 1 EFPY, one at 12
Given the above revised figure, the materials surveillance program at St.
Lucie, Unit 2, is in compliance with Appendix H of 10 CFR 50.
- 4. 0 CONCLUSION The staff agrees with Florida Power and Light Company that the revised figure of neutron fluence versus transition temperature shift is more appropriate to St.
Lucie 2 than Figure B 3/4.4-1 of the current Technical Specifications.
This revised figure supports the conclusion that at end of license the bounding transition temperature shift in RTNDT is less than 200'F.
Consistent with Table j. of ASTM E 185-82, Table 4.4-5 of the Technical Specifications should reflect 3 capsules scheduled for with-drawal.
As this is the case, the licensee has a materials surveillance program in compliance with Appendix H of 10 CFR 50.
The revised figure should be incorporated into the Technical Specifications.
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s REFERENCES 1.
Safety Evaluation Report related to the operation of St.
Lucie Plant, Unit No. 2, Docket. No. 50-389, NUREG-0843, October 1981, by the
- USNRC, Office of Nuclear Reactor Regulation.
2.
Letter from J.
W. Williams, Jr., Florida Power and Light Company, to H.
R. Denton, NRC, dated November 5, 1985, including the attachment BAW-1880, September
- 1985, a report by Babcock and Wilcox entitled, "Analysis of Capsule W-83 Florida Power and Light Company, St.
Lucie Plant, Unit No. 2, Reactor Vessel Material Surveillance Program,"
Accession No.
8511110018 851105.
3.
Letter from C. 0.
Woody, Florida Power and Light Company, to A.
C. Thadani, NRC, dated July 15, 1986 including Attachments 1, 2, and 3, Accession No. 8607220403 860715.
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Letter from,C.
0.
Woody, Florida Power and Light Company, to E.
G. Tourigny, NRC, dated September 4, 1986, and Attachment, Accession No.
8609100021 860904.
5.
Letter from C. 0.
Woody, Florida Power and Light Company, to A.
C. Thadani, NRC, dated December 2, 1986, Accession No. 8612090657 861202.
6.
Letter from C. 0.
Woody, Florida Power and Light Company, to U.S. Nuclear Regulatory Commission, dated April 1, 1987, Accession No.
8704060546 870401.
7.
Letter. from C. 0.
Woody, Florida Power and Light Company, to U.S. Nuclear Regulatory Commission, dated May 17, 1987, Accession No.
8705270061 870517.
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