ML20205J283

Application for Proposed Amend 140 to License DPR-54, Authorizing Increase of RCS High Pressure Reactor Trip Setpoint & Anticipatory Reactor Trip on Turbine Trip Arming Threshold to Increase Plant Availability.Fee Paid

ML20205J283
Person / Time
Site:	Rancho Seco
Issue date:	01/24/1986
From:	Rodriguex R, Reinaldo Rodriguez SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Miraglia F, Miraglia R, Miragliz F, Miragliz R Office of Nuclear Reactor Regulation
Shared Package
ML20205J285	List: ML20205J283 ML20205J306
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.K.3.02, TASK-2.K.3.07, TASK-TM RJR-85-606, TAC-61473, NUDOCS 8601300146
Download: ML20205J283 (5)

Text

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esuu.SACRAMENTO MUNICIPAL UTluTY DISTRICT 62o1 S Street P.O. Box 15830. Sacramento CA 95852 1830.1916)452 3211 AN ELEC TRIC SYSTEM SERVING THE HEAR T OF C ALif-OHNIA RJR 85-606 January 24, 1986 DIRECTOR OF NUCLEAR REACTOR REGULATION ATTENTION FRANK J MIRAGLIA JR DIRECTOR PWR-B DIVISION U S NUCLEAR REGULATORY COMMISSION WASHINGTON DC 20555 DOCKET-NO. 50-312 LICENSE N0. DPR-54 PROPOSED AMENDMENT NO. 140 In accordance with 10 CFR 50.59, the Sacramento Municipal Utility District proposes to amend its Operating License DPR-54 for Rancho Seco Nuclear Generating Station Unit No. 1.

Proposed Amendment No. 140 to the Rancho Seco Technical Specifications com-prises increases of the RCS high pressure reactor trip setpoint and of the anticipatory reactor trip on turbine trip arming threshold. These changes meet the established regulatory requirements for the Reactor Protection System (RPS) and Anticipatory Reactor Trip System (ARTS), complying with NUREG-0737, Items II.k.3.2 and II.k.3.7. B&W reports BAW-1890, Justification For Raising Setpoint for Reactor Trip On High Pressure, September, 1985 and BAW 1893, Basis for Raising Arming Threshold for Anticipatory Reactor Trip on Turbine Trip, October, 1985, provide the justification for these changes. These reports were submitted to the NRC, November 4, 1985, by the B&W Owner's Group.

Attachments I, II and III to this submittal provide the Safety Analysis, "No Significant Hazards" Evaluation and Description of Proposed Changes, respectively.

Pursuant to 10 CFR 50.91(b)(1), the Radiological Health Branch of the California State Department of Health Services has been informed of this proposed amendment by copy of this submittal.

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RANCHO SECO NUCLEAR GENERATING STATION O 14440 Twin Cities Road, Herald, CA 95638-9799;(209) 333 2935

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s F J MIRAGLIA Enclosed is a check in the amount of $150.00 as required by 10 CFR 170.21,

" Schedule of Fees."

Should you require any further information with respect to this Proposed Amendment, please contact Mr. Ron W. Colombo at Rancho Seco Nuclear Genera-g tion Unit No. 1. ,

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R. J. R RIGU ASSISTANTGENER(MANAGER, NUCLEAR Attachments (3)

Subscribe nd sworn to before me this c2 day of (f4 p k , 1986.

L 0 . la&a Notary Public '~

l , * , PATRICIA K. GEISLER

'* N(ytAlti ItTI.le-CA1.lFOflNIA

$4',Y ?'< rr.!NCr41. OFFICE IN M ar SACRAMENTO COUNTY Wy Commisse facires Febray 16,1988 1

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ATTACHMENT I SAFETY ANALYSIS Proposed Amendment No. 140 consists of increasing the RCS High Pressure Reactor Trip Setpoint and the anticipatory reactor trip on arming ~ threshold to 2,355'psig and 45% reactor power, respectively. .These improvements.will increase plant availability while decreasing the frequency at which plant safety systems are challenged.

Operating plant statistics for B&W plants during the years 1980 through 1984 indicate 52 anticipatory trips due to turbine. trips. . Twelve of these trips occurred with initial power below 40%. Based on assumptions of an ART arming threshold of 45% reactor power, and a turbine trip frequency.similar to the 1980-84 operating statistics cited above, it is estimated that a reduction of 0.24 trips per reactor _ year could be achieved.

The proposed changes meet the established regulatory requirements for the RPS and ARTS. Specifically, compliance has been demonstrated with NUREG-0737, Items II.k.3.2 and II.k.3.7. Two B&W reports provide an in-depth safety analysis and justification for the proposed changes. -These B&W reports.are BAW-1890, Justification for Raising Setpoint for Reactor Trip on High Pressure, September 1985 and BAW-1893, Basis for Raising Arming. Threshold for Antici-patory Reactor Trip on. Turbine Trip, October 1985.

SMUD is. committed;to reducing reactor trips with the objective of improving ~

, plant availability and safety. The changes to be made by Proposed Amendment 140 are considered improvements to plant safety by reducing unnecessary challenges to the plant safety systems.

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ATTACIMENT II "N0 SIGNIFICANT 11AZARDS" EVALUATION Proposed Amendment No. 140 to the Rancho Seco Technical Specifications does not match any of the examples presented in 48 FR 14870. .Therefore, our evaluation for significant hazards consideration is based solely on 10 CFR 50.92(c). The following considerations were evaluated:

a) Increase the probability of a previously evaluated accident - The proposed increases of the reactor high pressure trip from 2300 psig to 2355 psig, and the percent reactor power at which ARTS is disabled from 20% to 45% has been evaluated, and based on the safety analyses pro-vided in B&W reports BAW-1890 and BAW-1893 are judged to have constituted no increases on the probability of any previously evaluated accident.

b) Possibility of a new or different accident not previously evaluated -

Since 2355 psig is the design high pressure trip setpoint, the original FSAR analyses remain applicable for this setpoint. At a pressure trip setpoint of 2355 psig, successful runbacks from 45% power can be achieved. Thus a new or different accident not previously evaluated is considered impossible.

c) Reductica in the margin of safety - The increase in the reactor high pressure trip from 2300 psig to 2355 psig is judged to have negligible impact on the frequency of opening the PORV during anticipated over-pressurization transients. The sum of the transient induced pressure overshoots and the total effective instrument string errors would re-sult in the PORV (set at 2450 psig) opening one time out of 100,000 high pressure trip transients. This is sufficiently low probability to satisfy the NRC small break LOCA criteria for the PORV.

On the basis of the above, the proposed changes are judged to not involve significant hazards considerations.

l ATTADO U T III

} DESCRIPTION OF PROPOSE 0 CHANGES j.

Section 2.2 Bases, page'2-4: Changed reactor high pressure trip setpoint-

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from 2300 psig to 2355 psig, two places'.

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! 2. Section 2.3 Bases,C, page 2-7: Changed.high reactor coolant. system

{ pressure from 2300 psig to 2355 psig.

3. Table 2.3-1, page 2-9: Changed high reactor coolant system pressure,

j. psig max. from 2300 to 2355.

[ 4. Table 2.3-1, footnote (6), page 2-9: Changed ART " disabled" value from 4 20%-to 45%.

• T l 5. Figure 2.3-1, page 2-10: Changed P = 2300 psig to'P = 2355 psig.

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