ML20235J886
| ML20235J886 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 07/08/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20235J877 | List: |
| References | |
| TAC-65078, TAC-65079, NUDOCS 8707160046 | |
| Download: ML20235J886 (4) | |
Text
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>RRfCo UNITED STATES
+
8 NUCLEAR REGULATORY COMMISSION 3
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'.1 l WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 81 AND 74 TO FACILITY OPERATING LICENSE N05. DPR-42 AND DPR-60 NORTHERN STATES POWER COMPANY PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-282 AND 50-306 l
- 1. 0 INTRODUCTION
- c..
By letter dated April 13, 1987, Northern States Power Company (NSP, the licensee), requested amendments to Facility Operating License Nos. DPR-42 and DPR-60 for the Prairie Island Nuclear Generating Plant, Unit Nos. 1 and 2 (PINGP).
The amendments would change the technical specifications by revising the hot channel factors F and F that are used in the analysestoestablishthepowerdistr9butionyimitsofthetechnical A
specification (TS).
Specifically, the changes would affect Section TS 3.10-B1 and 2, add Figure TS 3.10-8, and change the Basis of Section TS 2.1.
2.0 DISCUSSION AND EVALUATION The existing TS have single limits for each of the nuclear hot channel factors, F and F while the amendment request proposes a change allowingavariabkU'functionforbothF and F 9
1(attached)whichwillbeincludedin9heTS$$asillustratedinFigure Figure TS 3.10-8.
The proposed variable function for both F and F allows operational flexibility by taking advantage of the typical pe3ks and Ualleys of F and F O
q 3g throughout the fuel cycles.
The licensee conducted analyses in accordance with 10 CFR 50.46 using the staff-approved Westinghouse 1981 Evaluation Model (see Refs. 3 and 4).
Three sets of hot channel factors were used for the analysis of the limiting large break loss-of-coolant accident (LOCA) transient.
Results of the analysis showed peak clad temperatures to be within the 2200 F regulatory j
limit for the three sets of values used to generate the curve (see Figure 1).
I In Figure 1, three points are plotted on F F
F ) axes.
A
)
linearcurvehasbeenproposedwithboundafibs3 ) and F "4 EndF tF =$
=
i 1.66, neither of which is to be exceeded.
However,9duetothenakdreof
]
the graph, these two maximum values would not be allowed to occur simultaneously.
The highest peak clad temperature (PCT) generated in the analyses occurred for F = 2.40 with a corresponding F
=1 Includinguncertaintiesformixedcoredesign,usedbythekcense.60.
9 e and I
8707160046 87070G PDR ADOCK 050002G2J p
, previously approved by the staff, the PCT was 2197 F.
For the bounding of F of 1.66 and corresponding F of 2.32, the PCT was calculatedto$e2125F.
Because staff-app 9oved methods were used and the results maet the regulatory limits of 10 CFR 50.46, this proposed TS change is acceptable.
Figure TS 2.1-1 in the TS specifies core safety limits of average core temperature and percent power not to be exceeded by the plant for given pressure values.
The figure is used to generate trip setpoint values; however, the accident analysis done for the large break LOCA transient does not take credit for any trips.
Therefore, analyses were performed for all bounding transients excluding the large break LOCA.
For turbine trip, rod withdrawal, dropped rod, locked rotor, and loss of reactor coolant flow transients, the hot channel factors of F
=2 theOropos.50andFedvalue$N=fF 1.70 resulted in acceptable DNBR values.
Since o
= 2.50 and F
= 1.70 result in conservative coresafetylimitsandm8etregulatory$ requirements,theproposed change to the hot channel factor equation in the basis section of TS 2.1 (Page TS 2.1-2) is acceptable.
l o.
In conclusion, the licensee has proposed two changes concerning the hot channel factor.
The first change deals with a change in F and F from2.30and1.60,respectively,tothevariableexpressi8nshodHin Figure 1.
The second change deals with the maximum limits of F = 2.50 and F
= 1.70 proposed for the TS Section 2.1 for trip setpoinE applikSbility.
The staff finds that both requests meet applicable regulatory criteria and thus are acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The staff has determined that the 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 Commission has previously published a proposed finding that these amendments involve no significant hazards considera-tion 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 SSI.22(c)(9). Pursuant to 10 CFR 951.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.
4.0 CONCLUSION
The staff 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 manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
i i
l
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5.0 REFERENCES
1.
Letter from David Musolf, Northern States Power Company, to Document Control Desk, NRC, dated April 13, 1987.
2.
Memorandum from Charles Rossi, Assistant Director for DPL-A, to D.
Dilanni, Project Manager for PWR PD-1, dated April 2,1986.
3.
" Acceptance Criteria for Emergency Core Cooling Systems for Light Water Cooled Nuclear Power Reactors," 10 CFR 50.46 and Appendix K of 10 CFR 50,46 Federal Register, Vol. 39, No. 3 January 4,1974.
4 Eicheldinger, C., "WestingApose ECCS Evaluation Model, 1981 i
Version," WCAP 9220-P-A and VCAP 9221-A, Rev.1,1981.
Attachment:
Figure 1 Principal Contributors:
A. P. Gilbert o
D. C. Dilanni Dated: July 8, 1987 I
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Figure 1 U//////u 2.40 u
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l(2.4.1.6) l Operstfon NOT '
J Allowed 2.35- ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ - ~ ~ ~ ' - ~ ~ ~ ~ ~ -
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+:
2.25-i i
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2.20
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1.55 1.60 1.65 1.70 s
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FIGURE 3.10-8 Acceptable Values of F (F H) and FAH(F )
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