ML20082U957
| ML20082U957 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 09/13/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20082U953 | List: |
| References | |
| NUDOCS 9109230049 | |
| Download: ML20082U957 (4) | |
Text
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. g"og eP i 1. _ )J' 'A UNITED STATES
- . ' i. ! 2 NUCLEAR REGULATORY COMMISSION
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WAsHINotoN, D C 2f7A6 5 fff.T,Y,,E,$ p,AJ),Cp, p,Y,,T[J,,0f [J,C,E.,0f, pp,C,L f bp, f E,A,C,T 0!L RE GUL AT 10ll EELATED TO A14h0PEllT h0.160 TO FAClllTY OPERAT1hG LICENSE NO. OPP.-66 p,d,QUESNELIGHTCOMPANY OH10 EDIS0ft C,0ffPAli,Y
,P.Epp,5,Y,L,Vpp),A, PONER C_0MPAllY BEAVER VAL,L,E,Y, Ppp,EF,,5,TA,TJpp,,,Upj,T, pp,.,1 D0r.KET NO. 50-334 1.0 JtiTRODUCTION (Ref. 1), as amended by letters of April 19, By app (lication dated June I?,1990,(Ref. 3), Duquesne Light Company (DLC/the 1991, Pef. ?), and July PS, 1991, licensee) proposed an amendntent to the Appendix A Technical Specifications (TSs) for the Beaver Valley Power Station, Unit No.1 (BVPS-1). The proposed changes would increase the setpoint of the power-operated relief valves from 350 psig to 440 psig for low temperature overpressure protection (LTOP), and increase the minimum enable teniperature from 275'F to 29?*F for iniLiation of the LTOP sy s tem. The amendment would modify Limiting Ccnditions for Operation 3.1.2.4 (footnote), 3.4.1.6, 3.4.9.3, 3.5.3 (footnote) and 3.5.4.1.2, and Surveillance Requirements 4.1.2.4.2 and 4.5.3.P.
Bases Sections 3/4 1.2, 3/4 4.9, 3/4 5.2 and 3/4 5.3, and 3/4 5.4 also would he revised to reflect these changes.
The proposed changes reflect.the updated and t:RC-approved temperature-pressure limits (Figures 3.4-2 and 3.4-3 of the Technical Specifications) based on the requirements of Appendix G to 10 CFR 50, 2.0 EVALUATION Low temperature overpressure protection (LTOP) is provided by two power operated relief valves (PORV) on the pressurizer. These PORVs are set at a pressure hw enough to prevent violation of the 10 CFR Part 50, Appendix G heatup and cooldown curves should a reactor coolant system (RCS) pressure transient occur during low temperature operations.
For LTOP considerations, two types of events are considered as the design bases transients. The transients are:
(1) a mass input transient typically caused by a normal charging and letdown ficw mismatch after termination of letdown flow, and (2) a heat input transient typically caused by the restart of an RCS pump.
DLC determined the PORV setpoints based on the mass addition transient which was identified previously as the limiting case which results in the highest pressure increase.
The mass addition transient analysis was performed 9109230049 910913 DR ADDCK 0500 4
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assuming the letdown line is isolated while one centrif ugal charging purrp is I
operating with maximum charging f b.
The assumption of inaxinum flew from one charging purrp is consistent with the requirernents of the present Technical Specifications 3.1.P.3 and 3.5.3 which require one charging punp to be i
gerabic for boron injection or recirculation cooling in !! odes 4, 0, and C.
The enalysis for determining F0PV setroints was perforn:ed using the sorte methodology enployed in the BVPS-1 Final Safety Analysis Report.
The original n,ethodoingy is docun;ented in the Westinghouse Owners' Group (WOG) report dated July 1977, er d its supplement of September 1977.
The WOG rethodology used the LOFTRAtt conputer code to generate the PORY setpoints for a bounding envelop of n= ass addition rates. The plant specific PORV setpoints were then determined with plant specific pararmters and updated algorithms applicable to DVPS-1.
The plant-specific analysis is typically performed to determine the pressure overshoot past the LTOP setpoints such that the tenperature-pressure limits in accordance with the Appendix G requirernents are not exceeried during the RCS pressure transients at low temperature conditions.
Cased on the results of the trost limiting LTOP transients (Ref.1), DLC determined the naximum allowable PORV setpoints as a function of the RCS tempe.ature in Figure 2.16 of Attachment D of Reference 1.
The calculated pressure-temperature relationship shows that the PORV setpoint is equal to 730 psig when RCS temperatures are above 225*F, and the setpoint is reduced from 730 psig.to 444 psig as the RCS temperature decreases from 225*F to 85*F to niaintain the margin of the safety required by Appendix 0 considerations.
BVPS-1 does not have an automatic inechanism to adjust the PORV pressure setroint as the RCS temperature changes (Ref. 4). Therefore, DLC selected the lowest point on the calcubted PORV pressure.setpoint curve and initially proposed 444 psig (correspanding to the PCS temperature of 85*F) as the PORV setpoint in Technical Specification 3.4.9.3 for the LTOP conditions. This proposed setpoint was later revised to 440 psig (Pef. 3) as a-result of an analysis of increasing the steam generator tube plugging limit to 20%.
Since the calculated PORV setpoints are based on analyses using an approved methodology to demonstrate satisfaction of the temperature-pressure limits in accordance with the requirements of Appendix G to 10 CFR Part 50, the f4RC staff concludes that the proposed PORV setpoint (Ref. 3) for TS 3.4.9.3 is acceptable for operation of the BVPS-1.
I n response to the fiRC staff's review comment, OLC also changed tne enable tenperature from 275*F to 292*F for initiation of the LTOP system. _ The LTOP enable-temperature was determined by-following the guidance that for LTOP, the enable ternperature -is the water tenperature corresponding to metal temperature i
l of at least RT
-4 90*F at the vessel beltline. This was calculated by DLC to be less thaNr equal to 202*F during heatup and cooldown conditions. The DLC-proposed changes to the TSs and associated bases sections reflect the above discussed LTOP enable temperature. The NRC staff finds that the changes i.
are based on applicable regulatory guidance in Standard Review plan 5.2.2 L
-(Revision 2), are reasonably conservative, and are acceptable.
I
3-3.0 5,T,A,TE,,C,0RS_ULTAT10N in accordance with the Connission's r egulations, the Pennsylvania State officio 1
- was notifitd of the proposed issuance of the anendtnent. The State official had r o cone,ents, a. 0 T NV I P0pE N T Aj.,,00p,5) D,E R A,TJ,0p The amendment cherges a requirentr.t with respect to installation or use of a facility cor:ponent located within the restricted area as defined in 10 CFR Part 20 and changes a surveillaru requirenent. The NPC staff has deterniined ihat-the antndnent it.volves no significant increase in the amounts, and no significant change in the types of any effluents that may be released cffsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Ccmissien has previously issued a proposed finding that the anendntot involves no significant hazards _
i considetation, and there has been no public concent on such finding (55 FR 30601 and $6 FR 27042). Accordirgly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.fr(c)(9).
Pursuant to 10 CFR 51.22(b), no environnental inpact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 C,0pCLUS10N The Commission has 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 nianner, (2) such activities will be conducted in con.pliance with the Commission's regulations, and (3) the itsuance of the anendment will r.ot be inimical to the common defense and security or to the health and safety of the public.
6.0 -FEFERENCES 1.
Letter from J. Sieber (Duquesne Light Conpany) to NRC, " Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66, Proposed Operating License Change Request No. 176," dated June 12, 1990.
7.-
Letter from J. Carey (Duquesne Light Con,pcny) to NRC, " Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPP-66 Proposed Operating License Change Request No.176 Revision 1," dated April 19,
- 1991, i
3.
LetterfromJ.Sieber(DuquesneLightCon,pany)toNRC."BeaverValley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66, Proposed Operating License Change Request No.176, Revision 1" dated
. July ?5,1991.
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4 I
4 Letter f rom J. Sieber (Duc,uesne light Corapany) to fiRC, " Beaver Valley Power Station, Unit flo. 1, Docket 110. EC-334, license I:o. OPP-60, tdditional Inforr ation - 1AC 7(PE9" dated recer.ber 3,1990.
Principal Contributor:
S. Eun Date:
September 13, 1991
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