ML20236T867
| ML20236T867 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/18/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236T863 | List: |
| References | |
| NUDOCS 8712020137 | |
| Download: ML20236T867 (3) | |
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SAFETY EVALUATION BY THLD"FICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMEN!' MENT NO.134 TO cACILITY OPERATING LICENSE NO. DPR-50 METROPOLITAN EDISON COMPANY JERSEY CENTRAL POWER AND LIGHT COMPANY PENNSYLVANIA A ELECTRIC COMPANY GPU NUCLEAR CORPORATION THREE MILE ISLAND NUCLEAR STATION UNIT 1 DOCKET NO.: 50-289 INTRODUCTION By letter dated July 24, 1987, General Public Utilities Nuclear Corporation (GPUN/ licensee) preposed to revise the pressure-temperature limits in the Three Mile Island Nuclear Station Unit 1 (TMI-1) Technical Specifications.
The proposed limits will incorporate the updated pressure vs. temperature curves through 10 effective full power years (EFPY) to account for irradiation effects on the reactor vessel material. The proposed limits were based on the Babcock and Wilcox (B&W) analysis of irradiation data taken from several TMI-1 surveillance specimens (Ref. 1). The limits provide maximum )ermissible pressure at temperature for three reactor operations--system hydrostatic and leakage tests, heatup or cooldown, and core critical condition. The pressure
... nits at temperature have to satisfy the requirements in Appendix G of 10 CFR 50.
DISCUSSION Part of the NRC's effort to ensure integrity of the reactor vessel is to periodically evaluate the reduction in fracture toughness of the vessel material due to neutron irradiation damage. The effort consists of three steps. First, the licensee is required to establish a surveillance program in accordance with Appendix H of 10 CFR 50, which requires periodic withdrawal of surveillance capsules from the reactor vessel. The capsules are installed in the vessel prior to startup and they should contain test specimens that were made from the plate, weld, and heat affected zone materials of the reactor beltline. Secondly, the licensee is required to perform Charpy impact tests, tensile tests, and neutron fluence measurements of the specimens. These tests provide data for the actual neutron irradiation damage to the reactor vessel in terms of the reference temperature, RT and the upper shelf energy (USE).
Theneutrondamageisindicatedbythedeba,seinUSEandtemperatureshift in RT The USE is the average energy value for all specimens whose test tempeku.re is above the upper end of the transition temperature region. The USE decreases as a function of neutron fluence and copper content in the irradiated material. The shift of the adjusted reference temperature is the temperature shift in the Charpy curve for the irradiated material relative to that for the unirradiated material.
8712020137 871118 PDR ADOCK 05000289 P
1
. According to Appendix G of 10 CFR 50, the USE nust not be less than 50 ft-lb and the adjusted RT not more than 200 F.
Thirdly, the licensee is required to construct three N imum pressure-temperature curves for the three operating conditions mentioned above and incorporate the curves in the Technical Specifi-cations. To construct the curves, the licensee may use the guidelines delineated in Reg. Guide 1.99, Revision 2, and Appendix G,Section III of the ASME Code.
EVALUATION The proposed TMI-1 pressure-temperature limits were derived from the irradiation data taken from surveillance specimens in withdrawal capsule TMI-1C. This capsule is a part of the Integrated Reactor Vessel Materials Surveillance Program sponsored by the B&W owners group. The capsule was irradiated in cycle 1 of the TMI-1 reactor and in cycles 3 through 5 of the Crystal River Unit 3 reactor. The staff had reviewed and found the TMI-1 surveillance program, including the capsule withdrawal schedule, acceptable.
(Ref. 2 & 3).
Tbc TMI-lC capsule was removed during the fifth refueling outage of Crystal River Unit 3 for exagnatiog. The capsule experienced a cumulative neutron fluence of 8.66 x 10 n/cm (E 1MeV).
It contained base metal, correlation metal, heat-affected-zone metal, weld metal, and dosimeter wires. The contro11 ire material was included in the capsule, which was the middle circumferential weld, heat number WF-25. This particular weld metal was fabricated by B&W using a submerged-arc weld process with Linde 80 flux.
18 2
The WF-25 weld received a neutron fluence of 3.4 x 10 n/cm at the inside surface of the vessel. The copper and nickel content of the weld were 0.35%
and 0.68% respectively. The adjusted RT through the 10 EFPY at T/4 vessel walllocationwascalculatedtobe191*FilingRegulatoryGuide1.99,Rev.2.
The USE was estinated to be above the required 50 ft-lb through 10 EFPY. Both adjusted RT and USE satisfy the 10 CFR 50 Appendix G requirements.
NDT Presently, TMI-1 is in fuel cycle 6 which is equivalent to 4.83 EFPY. The staff believes that the proposed pressure-temperature limits are valid and that fracture toughness of the TMI-1 reactor vessel will be within the safety limits through 10 EFPY.
The staff has reviewed the proposed TMI-1 pressure-temperature limits and changes in the Technical Specifications. The staff has determined that the licensee has appropriately applied the methodology in 10 CFR 50, Appendix G and Regulatory Guide 1.99, Rev. 2.
The staff concludes that the pressure-temperature limits are valid through 10 EFPY and may be incorporated into the TPI-1 Technical Specifications, w_______-_--____
i ENVIRONMENTAL CONSIDERATION j
l This amendment changes a requirement with respect to installation or use of a l
facility component located within the restricted area as defined in 10 CFR l
Part 20. We have determined that the amendment involves no significant i
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 l
increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, this amendment meets the eligibility
'l criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant l
to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of t' :s amendment.
CONCLUSION We have 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, and (2) such i
activities will be conducted in compliance with the Comission's regulations l
and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
REFERENCES 1.
Lowe, Jr. A.L. et al, " Analysis of Capsule TMI l-C GPU Nuclear Three Mile Island Nuclear Station - Unit 1."
Babcock and Wilcox, BAW-1901, and Supplement 1 March 1986.
2.
Memorandum from D. Crutchfield to J. Thomas,
Subject:
GPU Nuclear Corporation, THI-1 (Tac No. #59813), March 24, 1986 3.
Menorandum from W. Johnson to G. Lainas,
Subject:
GPU Corporation TMI Unit 1, May 16, 1983 Dated: bovember 18, 1987 Principal Contributor:
J. Tsao 1
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