ML20238B018

Safety Evaluation Supporting Amend 134 to License NPF-1

ML20238B018
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	09/01/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20238A996	List: ML20238A992 ML20238B008 ML20238B018
References
NUDOCS 8709090508
Download: ML20238B018 (3)

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1 UNITED STATES

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j $g. NUCLEAR REGULATORY COMMI'SSION 4 WASHINGTON, D. C. 20566 J'

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SAFET EVALUATION BY THE '0FFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0.134 TO FACILITY OPERATING LICENSE N0. NPF-1 E

PORTLAND GENERAL ELECTRIC COMPANY

, THE CITY OF EUGENE, OREGON PACIFIC POWER'AND LIGHT COMPANY-TROJAN NUCLEAR PLANT 4

DOCKET NO. 50-344 q

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1.0 INTRODUCTION

~By letter dated February 11, 1987, the Portland General Electric Company (PGE) submitted a request for changes to the Trojan Nuclear-Plant

' Technical Specifications:(TS). The amendment would increase the setpoint tolerance for the pressurizer (TS 3/4.4.2) and main steam (TS 3/4.7.1) safety-valves from 1 percent to 22 percent.

b The licensee stated that the Trojan Nuclear Plant has experienced failures of surveillance tests.of the safety valves due to the current tight tolerance. Since the testing is performed during refueling out- '

. ages, test' failures would potentially impact the refueling schedule.

Therefore, the licensee requested the TS change to make the setpoint i tolerance more practical.

2.0 DISCUSSION AND EVALUATION The current.TS requires that all pressurizer code' safety valves shall be q operable with a lift setting of 2485 psig with tolerance of il percent. .

The'.TS also requires that all main steam line code safety valves asso-ciated.with each steam generator shall be operable and lif t at a pressure of il percent of the nominal setpoint which ranges from 1170 psig to 1230 psig. The licensee requested that the TS for all pressurizer and main steam safety valves be modified to increase the setting tolerance from il

. percent to 12 percent. The licensee submitted an analysis to support the proposed TS changes. The analysis was performed to demonstrate that there is sufficient margin in the Trojan plant design to allow the increase of the tolerance.

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The loss of electric load accident, which was identified as the bounding case for all pressurization events in the Trojan Updated Final Safety Analysis Report (UFSAR) was chosen for the analysis. The RELAP/M002 code was used to calculate plant syste:n response to the loss of electric load accident. Parameters simulating the Trojan plant were inputed to the code. Benchmark calculations were also performed against data taken during the turbine trip startup test of the Diablo Canyon Unit 2 plant.

The results of the analysis show that the calculated values and the measured values are in good agreement. The benchmark calculation indi-cates that the RELAP/ MOD 2 code is acceptable for plant systems response for this transient event.

A sensitivity study was performed to determine the effect of the setpoint tolerance of the safety valves on the primary and secondary system pressures. The analysis assumed the setpoint tolerance ranging from 1 percent to 4 percent. The results of the analysis indicated that the s peak pressure of the primary system increases from 2621.4 psia for 1 percent tolerance to 2698.6 psia for a 4 percent tolerance. The peak pressure of the secondary system also increases from 1261.5 psia for 1 percent tolerance to 1282.5 psia for a 4 percent tolerance. These pressures are less than the 110 percent of the design primary and sec-ondary pressures in accordance with the ASME code, that is 2750 psia fcr the primary and 1320 psia for the secondary system.

The analysis of the loss of electric load accident was performed with the same key assumptions used in the Trojan UFSAR. These assumptions are, therefore, acceptable. Further, the licensee justified the use of the RELAP/M002 by comparing the code calculated values with the data base obtained from the Diablo Canyon in-plant tests.

The analysis demonstrates that the ASME Code limit of the primary and secondary pressures will not be exceeded with a 4 percent tolerance on the safety valves. However, the licensee proposed TS changes (Section 3/4.4.2 and 3/4.7.1) from the current t1 pcrcent to 22 percent, which will provide sufficient margin to allow for allowance drift. The staff ,

concludes that the results of the analysis are acceptable. The propcsed I TS changes are reasonable and meet the requirements of GDC 15 of Appendix A to 10 CFR 50.

The licensee also proposed a change to the Bases for TS 3/4.7.1 to correct the value for the main steam system desiga pressure, i.e., 1230 psig instead of 1185 psig as stated in current TS. The value is consistent with that which is stated in the UFSAR. We find the proposed change to the Bases acceptable since the change is editorial.

We have reviewed the proposed TS change to the setpoint tolerance of ell safety valves and the supporting infomation provided by the Portland General Electric Company. Based on the above, the steff concludes that the proposed Technical Specification changes are acceptable.

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3.0 CONTACT WITH STATE OFFICIAL *!

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.The NRC staff has notified the Oregon Department ofj Energy of the pro-posed issutoce v this' imendnent alon!.with the proposed determination of no sianificnat hazards consideration. Nugments were received.

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4.0 ENVIRONMENTAL CONSIDERATION

hhis[ amendment jnvolves a change in thh installation or use of a facility s

component located within the restricted area as definJd yn 10 CFR Part y - 20.,aThe staff thas d;termined that the amendneat invoh:es no significant incehase in the amNots, and no significant*c%nge in the types, of any.

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effluents that may tie released offsite, and thit there is no significant.

'y , increase in individual,or cumulative occupsticn' aMradiation exposure.

if ,The Commission has previously published a proposed 5fi ding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. 'Accordingly, thcs amendment meets 'j the eligibility crf teria for categorical exclusion set forth in 10 CFR 951.P2(c)(9). Pursucnt to 10 CFR 551.22(b), no environmental impact statianent or environmental assessment need be prepared ir connection with .

the iisuance'of the amendment. \ </

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We have concitded, based on the considerations dist.ussed above, that (1) there isieasobble assurance that the health andf safety of the public

. - wiil 'not be enc 4ngered by operation in the proposed manner, and (2) such .

ill'be conducted > in complianca with theiCommission's regula- r activitieC tions, and w(3) thesissuar.c4 of the amendment will ndt be isnjmical to the

.;, commer xdefense and security or to the health and safety WVhe public.

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6.0 PRINCIPAL CONTR GUTOR:

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