ML20236H645
| ML20236H645 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 10/22/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236H638 | List: |
| References | |
| NUDOCS 8711040250 | |
| Download: ML20236H645 (3) | |
Text
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ff UNITED STATES y
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NUCLEAR REGULATORY COMMISSION
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WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION j
RELATED TO AMENDMENT NO. 113 TO FACILITY OPERATING LICENSE NO. DPR-59 j
POWER AUTHORITY OF THE STATE OF NEW YORK JAMES A. FITZPATRICK NUCLEAR POWER PLANT DOCKf[N0.50-333 1
INTRODUCTION By letter dated March 16, 1987, the Power Authority of the State of New York proposed to revise the pressure-temperature limits in the James A. FitzPatrick l
Nuclear Power Plant Technical Specifications (TS), Section 3.6.
The pro pressure-temperature limits were developed from a General Electric (GE) posed report l
that the licensee submitted on April 12, 1985.
The report is entitled, " James A.
FitzPatrick Nuclear Power Plant Reactor Pressure Vessel Surveillance Materials t
Testing and Fracture Toughness Analyses," MDE-49-0386.
The pressure-temperature limits are a set of curves that set minimum pressure and temperature for three reactor operating conditions:
system hydrostatic and leakage tests, heatup or cooldown, and core critical operation.
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, i
the licensee is required to establish a surveillance program in accordance with I
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 contain test specimens that are 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, 4
RT and the upper shelf energy (USE). The neutron damage is indicated by th$DbecreaseinUSEandtemperatureshiftinRT The USE is the average energyvalueforallspecimenswhosetesttempeku.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.
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According to Appendix G of 10 CFR 50, the USE must not be less than 50 ft-lb, and the adjusted RT not more than 200 F.
Thirdly, the licensee is required tocalculatetheadh[tedRT Re ulatory Guide 1.99, Revisb[ for a postulated flaw in the vessel wall.
1, may be used for this calculation.
To ca culate the corresponding pressure, the relationship between RT and the stress intensity factor of the postulated flaw as described in Aphkdix G of ASME Ccde,Section III may be used.
EVALUATION The FitzPatrick reactor vessel is a 218-inch diameter BWR/4 series.
It was constructed by Combustion Engineering to the 1965 ASME Code,Section III, including the Winter 1966 Addenda.
Three surveillance capsules are located at the 30', 120, and 300 azimuths of the core midplane. The capsule at 30 was removed during the 1985 outage which corresponds to 5.98 effective full power years (EFPY).
The removed capsule contained 36 Charpy specimens, 8 tensile specimens, and 9 flux wires. The Charpy and tensile specimens were identified to be from the beltline region of the vessel, including plate, weld and heat affected zone materials.
The construction and selection of surveillance specimens satisfy the requirements of Appendix H of 10 CFR 50.
A boiling water reactor vessel has an inherent pressure-temperature limitation when the reactor water level is within the normal range for power operation and the reactor pressure is less than 20 percent of the preservice system hydrostatic test pressure.
In this case, Appendix G of 10 CFR 50 states that the pressure-temperature curve is limited by the closure flange regions that are highly stressed by the bolt preload.
The minimum permissible temperature above20%ofthehydrotestpNIsure,heflangeandwhenthetestpressureis is 60 F above the initial RT of t the permissible temperature should be 90 F above the initial RT The proposed FitzPatrick pressure-temperature curvessatisfytheserequhdm.ents.
Another temperature limitation in the older boiling water reactors pertains to feedwater nozzles, which are prone to cracking.
In the 1970's, the feedwater nozzles in BWR plants were found to have cracks due to feedwater leaking through the thermal sleeve and sparger.
The nozzle cracking problem has since i
been resolved.
Nevertheless, a pressure-temperature limit is required for heatup, cooldown, and critical operation to eliminate future cracking.
The proposed pressure-temperature limit for the feedwater nozzle case is based on j
the curve that is contained in the existing TS.
j At higher temperature and pressure ranges, the pressure-temperature limits are based on the material that has the largest shift between the adjusted RT and NDT the initial RT The plate was found to be the limiting material for i
operation up t$DI6 EFPY and has an adjusted RTtheweldwillbethelimitin Beyond 16 EFPY, higher irradiation shift.
The staff has determined that the three proposed pressure-temperature curves satisfy the safety margins as required by Appendix G of 10 CFR 50.
't The upper shelf energy for the plate at end-of-life is predicted to be 58 ft-lb which exceeds the required 50 ft-lb of Appendix G.
The adjusted RT at end-of-life for the weld is 104 F which is below the required 200 F.DTBased on N
this finding, the FitzPatrick reactor vessel satisfies the applicable 10 CFR 50 requirements.
In summary, the staff has determined that the licensee has adequate surveillance capsules for the reactor beltline materials inside of the reactor vessel and has an acceptable fracture toughness testing program for the irradiated materials.
The licensee has appropriately applied Appendix G of 10 CFR 50 and Regulatory Guide 1.99, Revision 1, to develop the pressure-temperature limits. These limits are valid up to 16 EFPY and may be incorporated into the FitzPatrick TS.
Revised TS sections 3.6 and 4.6, Limiting Conditions for Operation and l
Surveillance Requirements, respectively, as well as the revised bases for these sections, have also been reviewed. The staff finds that the changes reflect the revised pressure-temperature limits and satisfy the guidelines in the Standard Technical Specifications for General Electric Boiling Water Reactors (NUREG-0123) and are, therefore, acceptable.
ENVIRONMENTAL CONSIDERATION This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The 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 exposur e.
The Comission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on 3
such finding. Accordingly, this amendment meets the eligibility criteria j
for categorical exclusion set forth in 10 CFR Sec 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 this amendment.
4 CONCLUSION
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We have concluded, based on the considerations discussed above, that:
(1) there I
is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations 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.
Dated: October 22, 1987 PRINCIPAL CONTRIBUTOR:
J. Tsao l