ML17338B174
| ML17338B174 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 09/26/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17338B173 | List: |
| References | |
| NUDOCS 7910170441 | |
| Download: ML17338B174 (4) | |
Text
UNllED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMIENDMENT NO.
50 TO FACILITY OPERATING LICENSE NO. DPR-31 FLORIDA PORER AND LIGHT COMPANY TURKEY POINT NUCLEAR GENERATING UNIT NO.
3 DOCKET NO. 50>>250 Int'roduction By application dated August 7, 1979 (L-79-215), Florida Power and Light Company (the licensee) requested amendments to Facility Operating License Nos.
DPR-31 and DPR-41 for the Turkey Point Plant, Unit Nos.
3 and 4.
The application requested amendments to allow ten effective full power months (EFPM) of operation for each unit prior to performing another steam generator inspection.
Operation for ten effective full power months had been requested in the application for amendments dated March 6, 1979 (L-79-51) and May 18, 1979 (L-79-122).
B'ack round By letter (L-79-51) dated March 6, 1979, the 'licensee submitted the results of the most recent steam generator inspection for Turkey Point Unit 3 and requested authorization 'to operate ten effective full power months, beginning March 29, 1979, prior to the next steam generator inspection.
The technical basis for the preventative plugging program implemented sub-sequent to the inspection was consistent with that for programs performed previously at this and other similarly degraded units.
These programs have been determined adequate by the Nuclear Regulatory Commission (NRC) to support six effective full power months of operation.
The plugging criteria implemented during this inspection were more conservative than those implemented previously for six months operation to support the request for ten effective full power months of operation.
As indicated in our Safety Evaluation Report (SER) dated March 30, 1979, supporting Amen'dment 46, current autholization to operate Turkey Point Unit 3, we did not have an adequate technical basis to predict steam generator performance for periods longer than six EFPM at a time, and that our consideration of extended operation beyond six EFPM would depend on the operating experience at this and similarly degraded PNR units.
Accordingly, License Amendment 46 authorized Turkey Point Unit 3 to operate for only six effective full power months.
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By letter (L-79-215) dated August 7, 1979, the licensee again requested an amendment to the operating license for Turkey Point Unit 3 to allow ten effective full power months of operation prior to the next steam generator inspection.
The licensee has justified the request on the basis of the March 6, 1979 submittal, existing steam generator operating restrictions, and the continued leak free operation of Turkey Point Units 3 and 4 since March 29 and June 1, 1979, respectively.
The March 6, 1979 submittal regarding the results cf the most recent steam generator inspection and the implemented plugging criteria at Turkey Point Unit 3 was discussed and evaluated in the SER att"ched to License Amendment 46 dated March 30, 1979.
The March 30, 1979 SER is incorporated into this Safety Evaluation by reference.
Evaluation Turkey Point Unit 3 has operated since the authorized restart on March 29, 1979 (approximately 5-1/2 EFPM) without detectable steam generator leakage.
Similarly, Turkey Point Unit 4, where the denting phenomenon is more advanced, has operated approximately three months into,the current cycle without detectable steam generator leakage.
This experience plus the results of the most'ecent inspections at these units indicate that the denting phenomenon remains-in a predictable mode.
In addition, the preventative plugging criteria implemented by the licensee in January 1979 and evaluated in our above referenced SER were based upon the predicted growth (using finite element analysis) of the 17.5$ tube hoop strain contour during a ten month operating interval.
These criteria were proved to be more conservative than those employed in previous inspections at this and at similarly degraded units which were based upon the, predicted growth of the 17.5% contour over a six month operating interval.
The basis for these plugging criteria have been previously accepted by NRC and been shown to adequately support six months of steam generator operation.
As expressed in our above referenced
- SER, we continue to have reservations regarding the validity of extrapolating the predictive methodology beyond six months.
We find that there remains an insufficient technical basis upon which to authorize a four month extension to the currently authorized
3 six month operating interval.
Considering, however (1) that the implemented plugging criteria were significantly more conservative than the criteria already accepted by NRC as being adequate to support six months of operation, and (2) that the currently authorized six EFPH operating interval has essentially been completed with no detectable steam generator
- leakage, we conclude that operating interval may be extended until the upcoming November refueling outage but limited to seven weeks (effective full power) without significantly altering our previous conclusions that the steam generator tubes will maintain an acceptable degree of integrity.
The above considerations, together with the existing licensing conditions restricting steam generator operation in the event that detectable leaks occur, provide reasonable assurance that the health and safety of the public will be protected.
Environmental Consideration We 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
$51.5(d)(4), that an environmental'mpact statement or negative declaration and envir on-'ental impact appraisal need not be prepared in connection with the issuance of this amendment.
Conclusion I
We have concluded, based on the considerations discussed above, that:
'1) because the amendment does'not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, and (3) 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.
,Date:
September 26, 1979