ML17214A609
| ML17214A609 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 12/20/1983 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17214A608 | List: |
| References | |
| NUDOCS 8312280071 | |
| Download: ML17214A609 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O. C, 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AIIENDMENT NO.
TO FACILITY OPERATING LICENSE NO.
NPF-16 FLORIDA POWER AND LIGHT COMPANY ORLANDO UTILITIES COMMISSION OF THE CITY OF ORLANDO, FLORIDA AND FLORIDA MUNICIPAL POWER AGENCY ST.
LUC IE UNIT 2 DOCKET NO. 50-389 Back round In letters dated June 6, 1983 and June 28, 1983, Florida Power and L'iaht Company (FP8L) renuested a license amendment to modify the Standard Tech-nical Specification (STS) 3/4.3 "Turbine Overspeed Protection," for St. Lucie Plant, Unit No.
2 from a turbine valve testing freouency of once a week to once a months Discussion The staff's current position reauiring weekly test'.na of turbine valves as stated in Standard Review Plan Section 10.2 "Steam Turbine" was established after extensive discussions with major steam turbine manufacturers and is based largely on engineering judgement and the recommendations of these manufacturers.
Westinghouse, in a meeting on March 23, 1983 with the staff, presented results of an ongoing study on the generation of turbine missiles being conducted on behalf of some licensees and applicants.
This study specifically includes consideration of the testina requirements for the turbine overspeed protection valves and turbine valve arrangement of the type installed at St.
Lucie 2.
The results of this study are not final.
Preliminary indications are that turbine valve operability and reliabilitv will not be significantly affected by in-creasing the periodic valve testing from the present weekly to much longer interval.
- However, in Westinghouse's
.judoement, lack of a significant number of valve failures, good operating experience, and a well planned turbine valve maintenance and inspection program provide reasonable bases to increase the periodic test interval for turbines with valve arrangements as installed at St. Lucie 2 from weekly to monthly.
WIestinghouse stated that they intend to make a formal recommendation to their customers who have turbines employing turbine valves and steam chest arrangements, of the type installed at St.
Lucie 2, to change from periodic weeklv to monthly valve testing.
83i228007i 83i220 3
PDR ADOCK 05000389 P
The staff has evaluated the information submitted by FP&L in the 3une 1983 letters and Westinghouse information presented at the March 23, 1983 meeting.
Considering the information presented by FP8L and Westinghouse and the staff's original basis for the
- STS, the staff concludes that the interval between periodic turbine valve testing can be increased for St.
Lucie 2 from weekly to monthly, on an interim basis, pending establishment of a new piobabilistic turbine missile position that is currently being prepared by the the staff, and completion of the review of the Westinghouse generic report on the subject, without significantly affecting the capability of the turbine valves to function on demand.
In summary, the basis for considering Technical Specification relief at St.
Lucie 2 was:
1.
Lack of a satisfactory statistical basis to determine frequency of turbine valve testing.
Up to now test frequency o< these valves has been largely based on experience with turbine generators installed in fossil plants.
The Westinghouse turbine missile study, when completed and evaluated by the staff, is in-tended to provide a basis to establish turbine valve test frequency for nuclear units.
2.
The FP8L maintenance, inspection, and turbine valve test proaralii described in the Final Safety Analysis Report (FSAR) and the pro-posed modification to the Technical Specifications appears tc be satisfactory.
This Drnqram, performed on a periodic basis coup>i d with monthly testing of all turbine valves, is satisfactory to the staff on an interim basis pending completion of the turbine missile study.
3.
The date and rationale presented by Westinghoiise at the March 23, 1983 and other previous meetings with the staff and the staff's understanding of the data presented to date.
4.
Testing of turbine control valves on base loaded machines necessi-tates reduction of generator output for a period of several hours.
The valve testing sequence during turbine operation requires placing the turbine on manual control and repositioning all turbine conti nl valves in the steam chest to permit individual full valve strokino.
All valves are aligned to equal position.
Repositioning of the control valves (on a
base load machine) results in reduced steaiii flow to the turbine with a consequent reduction in generator outpiit of about 5%.
Testing of all turbine control valves is accomplished in a relatively short time (about 35 to 40 minutes).
The bulk nf the time consumed (approximately 2$ to 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />) is in slowly lowering ieactor output to correspond with the reduced turbine genei ator output to permit control valve testing.
On completion of valve tests, a similar time period is consumed in slowly increasing reactor power tn permit full load operation of the turbine generator.
The lowerinq and increasing of reactor output must be accomplished slowly to minimize xenon spiking.
This economic impact, although not a safety consideration, was factored into the staff action.
On the basis of the above, the staff concludes that extending the turbine valve testing interval at St. Lucie 2 as stated is acceptable subject to the following conditions:
1.
All turbine valves are to be tested
'once per month, twelve times per year.
2.
The decreased frequency of turbine valve testing is acceptable on an interim basis until the turbine missile generation probabi-lity analysis performed by Ilestinghouse is reviewed by the staff to confirm that the study results support the verbal statements made by Westinghouse representatives in meetings with staff mem-bers.
3.
FP8L uses only an all volatile treatment (AVT) program for main-taining secondary water chemistry.
The staff is in the process of evaluating the Westinghouse turbine missile generation probability analysis report.
The results of the staff review, in-cluding recommendations regarding continuation of decreased turbine valve testing frequency, will be reported in a future Safety Evaluation.
Environmental Consideration l<e have determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact.
Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 551.5(d)(4),
that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment.
Conclusion
'Me have concluded, based on the considerations discussed
- above, that:
(1) there is reasonahle 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 Commission'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.
>>te:
December 20, 1983 Pricipal Contributors:
R. Gardina, DSI R. Klecker, DE