ML20202G272

Forwards Request for Addl Info Re Proposed Amend 140 to License DPR-54,changing Tech Specs 2.2 & 2.3 to Increase Setpoint for Reactor Trip on High Pressure from 2,300 Psig to 2,355 Psig

ML20202G272
Person / Time
Site:	Rancho Seco
Issue date:	07/07/1986
From:	Stolz J Office of Nuclear Reactor Regulation
To:	Julie Ward SACRAMENTO MUNICIPAL UTILITY DISTRICT
References
TAC-61473, NUDOCS 8607150354
Download: ML20202G272 (3)

Text

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1. 3 N/6 1 . ,

July 7, 1986 Docket No. 50-312 Mr. John E. Ward Assistant General Manager, Nuclear (Acting)

Sacramento Municipal Utility District 6201 S Street P. O. Box 15830 Sacramento, California 95813

SUBJECT:

PROPOSED AMENDMENT 140, REQUEST FOR ADDITIONAL INFORMATION We have reviewed Sacramento Municipal Utility District's proposed Amendment 140 submitted January 24, 1986 requesting NRC's approval of changes in Technical Specification 2.2 and 2.3. The proposed changes would: (1) increase the setpoint for reactor trip on high pressure from 2300 psig to 2355 psig; and (2) increase the anticipatory reactor trip on turbine trip arming threshold from 20% of full power to 45% full power. Prior to processing your request we will need a response to the enclosed request for additional information.

Additionally, please note that license amendments are processed in accordance 1 with 10 CFR 50.90 and not 10 CFR 50.59 as frequently referenced in your submittals.

Sincerely, oit-tute s 4 w John F. Stolz, Director PWR Project Directorate #6 Division of PWR Licensing-B

Enclosure:

As Stated cc w/ enclosure:

See next page l

DISTRIBUTION ACRS-10 (Docket File BGrimes )

NRC PUR JPartlow I L PDR SMiner PBD-6 Rdg RIngram l

FMiraglia Gray File OELD NThompson EJordan Tech Branch w/ input GKalman to letter A f1 W l PBD-6 PB PBD-6 PD SMin GK an RWeller JStolz 7/ 7 /86 7/7 /86 7/ 7 /86 7/ 7 /86 8607150354 e60707 PDR ADOCK 05000312 P PDR c i I

.g Mr. John E. Ward Rancho Seco Nuclear Generating Sacramento Municipal Utility District Station cc:

Mr. David S. Kaplan, Secretary Sacramento County and General Counsel Board of Supervisors Sacramento Municipal Utility 827 7th Street, Room 424 District Sacramento, California 95814 6201 S Street P. O. Box 15830 Ms. Helen Hubbard Sacramento, California 95813 P. O. Box 63 Sunol, California 94586 Thomas Baxter, Esq. -

Shaw, Pittman, Potts & Trowbridge 1800 M Street, N.W.

Wasnington, D.C. 20036 Mr. Ron Columbo Sacramento Municipal Utility District Rancho Seco Nuclear Ger.erating Station 4440 Twin Cities Road Herald, California , 95638-9799 -

Mr. Robert B. Borsum Babcock & Wilcox Nuclear Power Generation Division Suite 220, 7910 Woodmont Avenue

. Bethesda, Maryland 20814 Resident Inspector / Rancho Seco c/o V. S. N. R. C.

14410 Twin Cities Road Herald, California 95638 Regional Administrator, Region V U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Director Energy Facilities Siting Division Energy Resources Conservation &

Development Commission 1516 - 9th Street Sacramento, California 95814 Mr. Joseph 0. Ward, Chief Radiological Health Branch State Department of Health Services 714 P Street, Office Building #8 Sacramento, California 95814

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REQUEST FOR ADDITIONAL INFORMATION

1. Considering Rancho Seco's bypass capabilities, atmospheric dump valve capacity and other plant specific features, will the higher setpoint for reactor trip on high pressure in combination with the increased Anticipatory Reactor Trip on Turbine Trip (ART) threshold result in more frequent challenges to the Main Steam Safety Valves (MSSVs)?

Also, compare the frequency of MSSV challenges for the proposed Technical Specification changes with the frequency of MSSV challenges for the initial plant design (i.e., 2355 psig and no ART). Provide the bases for SMUD's response. If the proposed changes to the Tech-nical Specifications will result in more frequent challenges to the MSSVs, then describe why the proposed changes are acceptable in regards to a stuck open MSSV.

2. Demonstrate that the accident analyses in the FSAR are consistent with the higher setpoint for reactor trip on high pressure in ccmbination with the increased ART threshold. In particular, are the accident analyses in Ch. 14 of the FSAR based on the high pressure trip set-point of 2300 psig or 2355 psig? Are the accident analyses in Ch. 14 based on the use of ART? At least the following accidents should be specifically considered: (1) the control rod ejection accident; (2) the start-up accident; (3) the rod withdrawal accident at rated power oper-ation; (4) the moderator dilution accident; and (5) loss of electric power. Revise the preceding accident analyses in the FSAR, as well as Ch. 4 and 7 (e.g., see Table 4.2-8, p. 4.2-43, and, pp. 7.1-9, 17), as necessa ry.

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