ML17222A524
| ML17222A524 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 09/22/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17222A523 | List: |
| References | |
| NUDOCS 8809290102 | |
| Download: ML17222A524 (4) | |
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UNITED STATES NUCLEAR R'EGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 35 TO FACILITY OPERATING LICENSE NUMBER NPF-16 FLORIDA POMER AND LIGHT COMPANY~ ET AL.
ST.
LUCIE PLANT, UNIT 2 DOCKET NUMBER 50-389 BACKGROUND By letter dated November 16, 1987, Florida Power and Light Company (FPL, the licensee) proposed changes to the Technical Specifications (TS) for the St. Lucie Plant, Unit 2.
The proposed changes would revise TS Sections 4.7. 1.5 and 4.7. 1.6 which specify the surveillance requirements for the main steam isolation valves (MSIVs) and main feedwater isolation valves (MFIVs),
respect ive ly.
DISCUSSION The proposed amendment consists of showing in TS Section 4.7. 1.5 the correct va lue of the blSIV response time, 6.75 seconds, consistent with TS Section 3/4.3.2, and adopting in TS Sections 4.7. 1.5 and 4.7. 1.6 the wording of the Combustion Engineering Standard Technical Specifications (STS) for the MSIV and the MFIV surveillance frequency requirements.
The first of the proposed changes is needed to resolve discrepancies in the TS between Surveillance Requirement (SR) 4.7.1.5.b and Table 3.3-5 parts 3f and 6b, based on the input values and terminology used in the stretch power safety analysis.
The second of the proposed changes is needed to eliminate duplication between the. TS and the Inservice Testing
( IST) Program and to adopt a
standard terminology for the MSIV and MFIV surveillance frequencies.
In a main steam line break (MSLB) analysis, it is necessary to assure that the MSIVs and MFIVs close within a certain time limit once the IISIV and MFIV closure initiating condition is reached (high containment pressure or low steam generat'or pressure).
This serves to minimize the positive reactivity effects of the reactor coolant system cooldown associated with the blowdown and to limit the pressure rise within the containment in the event of a steam line rupture within containment.
The MSIV time to the full closure requirement given in TS SR 4.7. 1.5.b currently reflects only the valve stroke time, 5.60 seconds.
The MSIV response time given in Table 3.3-5 parts 3f and 6b reflects the sum of the total instrument delay time plus the valve stroke time.
The licensee has allowed up to 1. 15 seconds 8809290102 880922 l
PDR ADOCN, 05000389 l,l P
PNU for instrument delay to yield the maximum response time, 6.75 seconds, shown in the table.
The proposed revision of SR 4.7.1.5 expresses the maximum valve closure time.
The staff finds this acceptable.
It should be noted that, with regard to the NFIVs, the time to full closure requirement given in SR 4.7. 1.6.b is the MFIV response time, 5.15 seconds, which agrees with Table 3.3-5 parts 3e and 6a.
Similar to the MSIV response time, ihe NFIV response time given in the SR and Table 3.3-5 reflects the sum of the total instrument delay time plus the valve stroke time.
Here the licensee has also allowed up to 1.15 seconds for instrument delay, yielding a
nominal valve stroke time of 4.00 seconds.
The licensee used a value of 6.75 seconds for the MSIV response time and 5.15 seconds for the NFIV response time in the stretch power NSLB analysis.
As long as the time from reaching the NSIV closure initiating condition to full valve closure is less than or equal to 6.75 seconds and the time from reaching the NFIV closure initiating condition to full valve closure is less than or equal to 5.15 seconds, regardless of the individual instrument response time or valve stroke time, the conclusions of the stretch power accident analysis, which were previously accepted by the staff, are applicable.
The above specified values for MSIV and NFIV stroke times are FSAR design values and are considered to be maximum allowable stroke times.
In order to avoid confusion for the TS values, the staff amended the applicable Bases statements to amplify this salient point.
In addition, since the TS references 4.0.5, the licensee' Inservice Testing Program should also make this point clear.
Any increase in stroke time beyond the maximum allowable values would call for valve correction action.
This Bases statement change was discussed with and agreed to by the licensee.
The staff would prefer the valve total closure time and the instrument response time to be measured at the same point of time (e.g.,
a refueling outage) in order to ascenain the current stroke time.
However, the staff will not require this in order to give the licensee operational flexibility. Adhering to maximum allowable stroke times before corrective action is undertaken will suffice.
The proposed changes would also revise the wording used in SRs 4.7.1.5 and 4.7.1.6.
The types, frequencies and conditions of tests currently delineated in these sections conform with the testing requirements of the ASME Code, 1980
- edition, committhd to in SR 4.0.5.
- Hence, by referencing SR 4.0.5 in the MSIV and MFIV SRs 4.7.1.5 and 4.7.1.6, respectively, the inservice testing required by the ASNE Code Article IWV-3410 and applicable addenda as incorporated in the licensee' IST Program, together with the corresponding response
- times, become the SRs for the Limiting Conditions for Operation (LCO) for NSIVs and NFIVs.
The staff finds this acceptable.
A SURMARY The modifications to the Technical Specifications proposed in this amendment by FPL, for the St. Lucie Plant, Unit 2, concerning tlSIV and MFIV surveillance requirements, are
'udged by the NRC staff to be adequate and acceptable.
ENVIRONt'1EllTAL 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 or changes to a surveillance requirement.
The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent's that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 551.22(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 the amendment.
CONCLUSION Me 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 will be conducted in compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Date:
September 22, 1988 Princi al Contributors:
John 0. Schiffgens E.
G. Tourigny