ML17347A818
| ML17347A818 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 07/18/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17347A817 | List: |
| References | |
| NUDOCS 8807280047 | |
| Download: ML17347A818 (3) | |
Text
q p,ft A5Q(y(
0 ss cs0 us p l
'ha**<
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AHENDIIENT NOS.
AND TO FACILITY OPERATING LICENSE NOS.
DPR-31 AND DPR-41 FLORIDA POWER AND LIGHT COIIPANY TURKEY POINT PLANT UNIT NOS.
3 AND 4 DOCKET NOS. 50-250 AND 50-251 BACKGROUND By letter dated January 16, 1987, Florida Power and Light Company (FPL, the licensee) initially proposed changes to the Technical Specifications (TS) for the. Turkey Point Plant Units 3 and 4, which are the subject of this Safety Evaluation (SE).
Following an NRC staff request for additional information, FPL resubmitted the request by letter dated April 5, 1988.
The proposed changes would revise the refueling shutdown margin from 10 to 5 percent (delta k)/k, correct a typographical error and make an administrative modifi-cation.
The changes, which are intended to bring the TS into closer confor-mance with the Westinghouse Standard Technical Specifications (STS), will simplify refueling activities and improve the consistency of the TS for Units 3 and 4.
DISCUSSION The proposed changes would modify the Turkey Point TS Section 3.10.8, Bases 83.10.8 and Tables 1.1 and 4.18-1 for Unit 3 and Unit 4.
Currently, the Turkey Point TS require that during refueling, the boron concen-tration of all filled portions of the Reactor Coolant System (RCS) and refuel-ing canal shall be sufficient to ensure that either the effective multiplica-tion factor (k f) is 0.90 or less or the boron concentration is greater than or equal to 19(I ppm, whichever is more restrictive The.proposed change would allow a 'refueling shutdown margin of 5 percent (delta k)/k, raising the maximum k f from 0 F 90 to 0 95.
and keep the refueling boron concentration requireme(iVof greater than or equal to 1950 ppm.
The licensee has calculated the time to criticality in the refueling mode (Mode 6) for a k
of 0.95 following initiation of a chemical and volume control system mFHunction (i.e.,
a boron dilution during refueling accident),
assuming a minimum RCS water volume, a maximum dilution flow rate of 230 gpm (which is conservative since normally only one charging pump moving 77 gpm is operating during refueling, not all three pumps),
an initial boron concen-tration of 1950 ppm (i.e., the minimum allowable by the TS),
and a critical 8807280047 8807l8 PDR
- DOCH, 05000250 P
PNU refueling boron concentration of 1450 ppm (i.e.,
a value which was chosen to be bounding for future cycles).
The calculation yielded a time to criti-cality, i.e.,
a time 'to detect and terminate the dilution event before criticality is reached, of 30.7 minutes.
As discussed in Standard Review Plan (SRP) Section 9.1.2, the NRC staff finds a maximum k f for a spent fuel pool of 0.95 acceptable.
Furthermore, the Westinghous5 ITS section dealing with boron concentration during refueling recommends a
k of 0.95 or less.
Improvements in calculational methods over the years have educed uncertainties allowing for the reduction in conserva-tism associated with the accepted decrease in the shutdown margin from 10 to 5 percent (delta k)/k. It should be noted that in calculating k
in accord-ance with SRP Section 9.1.2, a total uncertainty factor is deterNed by the licensee and added to the calculated k
to define the maximum possible keff Also, the instrumentation,
- alarms, and Qnunciators at Units 3 and 4 are adequate to provide the control room operators indication of a dilution event allowing sufficient time to mitigate the event, i.e., terminate the dilution event before criticality is reached.
For these reasons the staff finds the proposed increase in the maximum keff to 0.95 to be acceptable.
The proposed change in h
would require modifying Table 1.1, Section 3.10.0 and Bases B3.10.0 of the f for Unit 3 and Unit 4s The amendments also propose another change to Table 1.1 and changes to Table 4.18-1 for Units 3 and 4.
The other change to Table 1.1 is to correct a typo-graphical error, changing the Mode 5 average coolant temperature limit from
" " to "
or =" 200 degrees F.
The changes in Table 4.18-1 would bring it into conformance with Table 1.1, i.e., for each unit, the designations for the operational modes as defined in Table 1.1 would be used in Table 4.18-1.
The staff finds these changes acceptable.
SUMMARY
The modifications to the Technical Specifications proposed in these amendments by FPL, for the the Turkey Point Plant, Units 3 and 4, concerning modifications to the refueling shutdown margin and.the minor administrative
- changes, are judged by the NRC staff to be acceptable.
ENVIRONMENTAL CONSIDERATION These amendments involve changes in the installation or use of the facilities components located within the restricted areas as defined in 10 CFR Part 20.
The staff has determined that these amendments involve 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 Comnission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public comment on such finding.
Accordingly, these amendments meet the eligibility criteria 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 these amendments.
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 activities wi 11 be conducted in compliance with the Commission's regulations and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Dated:
July 18, 1988 Princi al Contributor:
John 0. Schiffgens