ML20206R788
| ML20206R788 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/12/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20206R783 | List: |
| References | |
| NUDOCS 9901200253 | |
| Download: ML20206R788 (5) | |
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UNITED STATES g
j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20566-0001
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SAFETY EVALUATION BY THE OFFICE OF NOCLEAR REACTOR REGULATION RELATED AMENDMENT NO.94 TO FACILITY OPERATING LICENSE NO. NPF-85 PECO ENERGY COMPANY LIMERICK GENERATING STATION. UNIT 2 DOCKET NO. 50-353
1.0 INTRODUCTION
In a letter dated September 14,1998, PECO Energy Company (the licensee) submitted a 1
request for changes to the Limerick Generating Station, Unit 2, Technical Specifications (TSs)
(Change Request No. 98-04-2). The requested change would revise TS Table 4.4.6.1.31 to l
change the withdrawal schedule for the first capsule to be withdrawn from 10 Effective Full Power Years (EFPY) to 15 EFPY. Also, the requested change will revise the withdrawal schedule for the second capsule to be withdrawn from 20 EFPY to 30 EFPY.
In addition, the licensee requested, for NRC approval, a revision to TS Surveillance Requirement 4.4.6.1.4. This revision will remove the references to flux wire removal and analysis that was originally required following the first cycle of operation. The referenced flux wires were removed following the first cycle of operation, but were misplaced before they were able to be analyzed. The proposed TS Surveillance requirement will be changed to refer to the flux wires that are located within the surveillance capsules, which will be removed and analyzed in accordance with the surveillance capsule removal schedule located in TS Table 4.4.6.1.3-1.
2.0 BACKGROUND
The surveillance program for Limerick Unit 2 was implemented to monitor the radiation-induced changes in the mechanical and impact properties of the pressure vessel materials. The original surveillance program was established in accordance with 10 CFR Part 50, Appendix H, and ASTM E185-73. Case A of ASTM E 185-73 applies to Limerick Unit 2, since the vessel has a predicted shift in the reference nil-ductility temperature of less than 100 'F and will be exposed to a neutron fluence of less than 5 x 10 n/cm over the design lifetime of the plant.
2 The original withdrawal schedule specifies the removal of the first and second surveillance capsules at 8 and 20 EFPY, respectively. The surveillance program for Limerick Unit 2 also includes a third capsule, which is a spare without a specific withdrawal schedule.
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3.0 EVALUATION Appendix H to 10 CFR Part 50, " Reactor Vessel Material Surveillance Program Requirements,"
l include criteria to monitor changes in the fracture toughness properties of ferritic materials in the reactor vessel beltline region of light water nuclear power reactors which result from exposure of these materials to neutron irradiation and the thermal environment. Appendix H to 10 CFR Part 50 endorses ASTM E185, " Surveillance Tests for Nuclear Reactor Vossels."
Appendix H states that "the design of the surveillance program and the withdrawal schedule
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must meet the requirements of the edition of ASTM E185 that is current on the issue date of the ASME Code to which the reactor vessel was purchased. In addition,10 CFR Part 50, Appendix H, states that a proposed withdrawal schedule must be submitted with a technical justification as specified in 10 CFR 50.4. The proposed schedule must be approved prior to implementation.
By ASTM E185-73, it is recommended that the capsules be withdrawn according to application by either one of these cases: Case A -where both the predicted increase in transition temperature of the reactor vessel steelis 100 'F or less and the calculated peak neutron l
fluence (E > 1 MeV) of the reactor vessel is 5 x 10'8 n/cm or less or Case B - where the 2
predicted increase in transition temperature of the reactor vessel steelis greater than 100 'F or where the calculated peak neutron fluence (E > 1 MeV) of the reactor vesselis greater than i
5x101e 2
n/cm. Case A applies to the Limerick Unit 2 surveillance program. Case A of ASTM E185-73 requires the first and second capsules be withdrawn at a capsule fluence corresponding to the calculated exposure of the reactor wall at approximately 100 to 125 percent of the reactor design life. The third capsule is to be a standby capsule.
In the submittal of September 14,1998, PECO Energy Company submitted a proposed l
I withdrawal schedule with a technicaljustification as specified in 10 CFR 50.4. The licensee's Justification for revising the withdrawal schedule for the first capsule from 8 EFPY to 15 EFPY is that, at 8 EFPY, the data may not be useful because the expected shift in RTwor is small and may be indistinguishable from the data scatter that would typically be experienced from the testing of an unirradiated specimen. The licensee's justification is the same for revising the withdrawal schedule for the second capsule from 20 EFPY to 30 EFPY. However, it was noted that the removal of the second capsule at 30 EFPY will meet the withdrawal requirements of l
Case A of ASTM E185-73. The third capsule also meets the withdrawal requirements of Case A of ASTM E185-73.
l In addition, PECO Energy Company requested, for NRC approval, a revision to TS i-Surveillance Requirement 4.4.6.1.4. This revision will remove the references to flux wire e
removal and analysis that was originally required following the first cycle of operation. The 4
referenced flux wires were removed following the first cycle of operation, but were misplaced before they were able to be analyzed. The proposed TS surveillance requirement will be changed to refer to the flux wires that are located within the surveillance capsules, which will i
be removed and analyzed in accordance with the surveillance capsule removal schedule l
located in TS Table 4.4.6.1.3-1. The NRC has determined that the deletion of removal and analysis of flux wires is acceptable because the analysis can be performed using the flux wires j
in the surveillance capsules, d
j e
. 4.0
SUMMARY
PECO Energy Company provided an acceptable justification, as specified in 10 CFR 50.4, for the revised withdrawal schedule of the first capsule in the Limerick Unit 2 surveillance program.
Section Ill.B.3 of Appendix H indicates that a proposed withdrawal schedule must be approved prior to implementation. Although the first capsule does not satisfy the schedule recommendations of ASTM E185-73, the staff noted that its removal at 15 EFPY is acceptable because it will receive a sufficient amount of neutron fluence to monitor the amount of ra tiation embrittlement. In addition, the staff noted that the second and third capsules meet
.,e recommended withdrawal s,chedule of ASTM E185 73. Therefore, the staff approves the revised withdrawal schedule, as indicated in TS Change Request No. 98-04-2, for Limerick Unit 2. Moreover, we find the proposed revision to TS Surveillance Requirement 4.4.6.1.4 acceptable.
5.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendment. The State official had no comments.
6.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes the surveillance requirement. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (63 FR 56253). Accordingly, the amendment meets the eligibility cr teria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
7.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Attachment:
Table Describing Status of Limerick, Unit 2 Surveillance Capsules PrincipalContributor: M. Khanna Date: January 12, 1999
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8.0 R_EFERENCES
1.
Letter from Mr. Garrett D. Edwards, PECO Enemy Company, to NRC Document Control Desk, dated Sept 3mber 14,1998, "Umerick Generating Station, Unit 2, Technical Specifications Change Request No. 98-04-2."
2.
Code of Federal Regulations, Title 10, Part 50, Appendix H, " Reactor Vessel Material Surveillance Program Requirements."
3.
American Society for Testing and Materials, " Standard Recommended Practice for Surveillance Tests for Nuclear Reactor Vessels," ASTM E 185-73.
4.
NUREG-1511 " Reactor Pressure Vessel Status Report," December 1994.
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e STATUS OF LIMERICK UNIT 2 SURVEILLANCE CAPSULES CAPSULE WITHDRAWAL TIME STATUS 13107717G003 15 EFPY TO BE TESTED 131C7717G002 30 EFPY TO BE TESTED 131C7717G001 STANDBY 1
ATTACHMENT
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