ML20081F202

Safety Evaluation Supporting Amends 61 & 60 to Licenses DPR-80 & DPR-82,respectively

ML20081F202
Person / Time
Site:	Diablo Canyon
Issue date:	05/23/1991
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20081F201	List: ML20081F199 ML20081F202
References
NUDOCS 9106070196
Download: ML20081F202 (5)

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EETY EVALUATION BY THE OFFICE 0F NUCLEAR Rf ACTOR REGULATION RELATED TO AMENDMENT NO.

61 TO FACILITY OPERATING LICENSE NO. DPR-80 AND AMENDMENT NO. 60 TO FACILITY OPERATING LICENSE NO. DPR-82 P_ACIFIC GAS AND ELECTRIC COMPANY A

DI ABLO CANYON NUCLEAR POWER PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-275 AND 50-323

1.0 INTRODUCTION

By letter dated July 17, 1990, Pacific Gas and Electric Company (PG&E or the licensee) requested amendments to the combined Technical Specifications (TS) appended to Facility Operating License Nos. DPR-80 and DPR-82 for the Diablo Canyon Power Plant (DCPP), Unit Nos. I and 2, respectively.

These amendments would revise the TS f or Diablo Canyon to increase the surveillance test interval (STI) for the Engineered Safety Features Actuation System (ESFAS) from monthly to quarterly testing and increase allowed outage times (A0T) f or ESFAS channels.

The proposed amendments would allow testing with channels bypassed rather than tripped and would no longer require staggered testing.

These changes are consistent with WCAP-10271 Supplement 2 and Supplement 2, Revision 1 " Evaluation of Surveillance frequencies and Out of Service Times for the Engineered Safety Features Actuation System" (References 5 and 6).

These changes would prevent inadvertent reactor trips and safeguards actuations during performance of instrumentation surveillances, thereby reducing the likelihood of unnecessery transients and challenges to safety systems.

The changes would also result in better management of resources to maintain the plant.

The NRC staff has reviewed the proposed changes to the TS and finds them acceptable based on the NRC staff's Generic Safety Evaluations approving the use of WCAP-10271 issued on February 22, 1989 and April 30,1990 (References 7 and 8).

2.0 EVALUATION The safety evaluations (SE) of the WCAP-10271 Supplement 2 and Supplement 2 Revision I concluded that the report provided an acceptable basis for certain TS changes.

The changes approved in the SEs of February 22, 1989, and April 30, 1990, are as follows:

1) the STl for ESFAS analog channels may be increased from 1 month to 3 months; 2) A0Ts for tes+ino of the analog channels may be increased from 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; 3) the A0Ts for testing of all components may be increased to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> in solid state systems; 4) the A0T for maintenance of all components may be extended to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />; 5) all components except the analog channels are to be in bypass during the maintenance A0T, with an analog channel tripped af ter spending 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> in bypass; and 6) staggered testing for ESFAS and Reactor Trip System (RTS) channels is not required.

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These TS changes were approved by the NRC for plant-specific use if the generic ar,alysis in WCAP-10271 is shown to be applicable to the plant and if any increase in instrunent drif t due to the extended Sils is accounted for in the setpoint calculation methodology.

2.) APPLICABILITY Of GENERIC ANALYSIS i

in the application of July 17, 1990, the licensee states that the generic analyses used in WCAP-10271 and its Supplements are applicable to Diablo Canyon Units 1 and 2 because the Westinghouse 7100 Process Control System and the Westinghouse Solid State Protection System are used at Diablo Canyon for both the ESFAS and RTS.

Both of these systems were specifically modelled in the generic analyses. The ESFAS functional units implemented at Diablo Canyon are all addressed by the generic analyses and the example changes to the TS are given in WCAP-10271. The NRC staff has reviewed the Diablo Canyon systems and finds that the WCAP-10271 analyses are applicable to Diablo Canyon.

2.1.1 Staggered Testing These changes to the Diablo Canyon TS delete the staggered testing requirenent from the Surveillance Requirements.

The licensee will continue to test on a staggered schedule, but it is-no longer required. A staggered testing program is no longer required for RTS or ESTAS channels, based on the staff's findings described in the SEs for the WCAP-10271 Supplenents. Therefore PG&E's proposed deletion of the staggered testing requirement is acceptable.

2.1.2 Common Cause Tailure Analysis In its application, PG&E stated that it has implemented procedures to evaluate failures for conron cause and require additional testing as necessary in accordance with the WOG Guidelines.

These procedures apply to both the ESFAS and_RTS.

Based on this_ information, the staff finds PG&E's implementation of procedures for common cause failure analysis to be acceptable.

2.1.3 Testing in Bypass Staff acceptance of testing in bypass is contingent on the capability to test in-hypass without lifting leads or installing temporary jumpers, as stated in the SE of WCAP-10271 dated February 21,1985 (Reference 1). The licensee states that bypass testing capability is installed for the containment pressure and seismic trip channels only.

For channels that do not have bypass testing capability, a channel that is f ailed such that the bistables are not tripped would be considered bypassed for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for the purpose of testing of another channel.- That channel would be tested in the tripped condition, so the plant would not be in a less conservative configuration than analyzed.

Since the-failed channel-is not tripped, the response from that channel would be the same as -if it was actually bypassed because no signal will cause that channel to trip.

Therefore, channel testing in the bypass mode is acceptable.

2.2 EVALUt, TION Of SETP0lki DRlri PG&E states that it has implemented a program to evaluate setpoint drif t in accordance with the Westinghouse Owners Group (WOG) position given in the

" Westinghouse Owners Group Guidelines for preparing Submittals Requesting Revision of Reactor protection System Technical Specification, Revision 1,"

issued on Septenber 3,1985 (Reference 4).

Based on this program, PG&E has determined that the values used in the setpoint methodology properly account for drif t due to extended ST!s.

The NRC staff has reviewed the WOG setpoint drif t methodology and did not take exception to it as stated in the staff's letter to the WOG on July 24, 1985 2.3 SPECIFIC CHANGES TO TECHNICAL SPECIFICATIONS TS 3.3.1, Table 3.3-1 of Diablo-Canyon TS contains Limiting Conditions for Operation for the RTS Instrumentation. Note (1) has been deleted because it refers to the ESTAS surveillance requirements which will not be different from the RTS surveillance requirements af ter these TS changes.

Action 26, allowing

-6 hours before requiring shutdown has-replaced Action 10 for the Safety Injection input and Automatic Trip and Interlock Logic channels.

This Action was approved by the staff in the february 22, 1989, SE and is therefore 6cceptable.

TS 4.3.1, Table 4.3-1 lists the Reactor Trip System Instrumentation Surveillance Requirements.

Note 12 has been deleted because it refers to the staggered testing that is no longer required as discussed above in section 2.1.1.

The removal of Note 13 is acceptable because it indicates that additional sur-veillance requirements are applicable to ESFAS inputs.

TS 3.3.2, Table 3.3-3 contains Limiting Conditions for Operation for the ESFAS Instrumentation.

The Action Statements have been changed to allow 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for an inoperable channel to be placed in the tripped condition, and to increase-the allowed bypass time for surveillance testing to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

These changes were analyzed in WCAP-10271 and approved by the staff's generic SEs.

TS 4.3.2.1, Table 4.3-2, lists the ESFAS Instrumentation surveillance require-

.nents.

The analog channel operational test interval has been changed from monthly to quarterly as approved in the SE dated February 22, 1989.

l In sumary, the NRC staff finds that the proposed changes to the Diablo Canyon l

TS are based on WCAP-10271 and its Supplements, which have previously been approved by the staff in SEs issued in February 1989 and April 1990.

The staff concludes, based on the review as described above, that the generic i-analysis is applicable to Diablo Canyon, and all criteria have been met.

3.0- STATE CONSULTATION In accordance with the Commission's regulations, the California State official was notified of the proposed issuance of the amendments.

The State official had no comments.

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4.0 INY!RONMENTAL CONSIDERATION i

i The ainendments change a requirement with respect to the installation or use of i

a facility component located within the restricted area as defined in 10 CfR i

Part 20 and change a surveillance requirement.

The NRC staff.has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any ef fluents that may be released of f site, 3

and that there is no significant increase in individual or cumulative occupa-tional radiation exposure. The Conmission has previously issued a proposed i

finding that the amendments involve no significant hazards consideration, and there has been no public coroment on such finding.

Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

5.0 CONCLtl510N The Connission 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, (2) such activities will be conducted in compliance with the Connission's regulations, and (3) the issuance of the amendment will not be inimical to the connon defense and security or to the health and safety of the public.

Principal Contributor:

A. Fitic rald i

Date:

May 23,1991

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6.0 REFERENCES

1.

Safety Evaluation by the Office of Nuclear Reactor Regulation of WCAP-10271,

• Evaluation of Surveillance frequencies and Out of Service Times for the Reactor Protection Instrurentation System,' February 21, 1985.

2.

Westinghouse Owners Group " Guidelines for Preparing Submittals Requesting Revision of Reactor Protection System Technical Specification,' May 16, 1985.

3.

Office of Nuclear Reactor Regulation " Discussion of Areas Where WOG Guidelines are Inconsistent with the NRC Safety Evaluation of WCAP 10271,"

July 24,1985.

4 Westinghouse Owners Group " Guidelines for Preparing Submittals Requesting Revision of Reactor Protection System Technical Specification, Revision 1,"

September 3, 1985.

5.

Andre G.R., Howard, R.C., Jansen, R.L., and 1.eonelli K., " Evaluation of Surveillance f requencies and Nt of Service Tines for,the Engineered Safety features Actuation System " WCAP-10271, Supplenent 2, February 1986.

6.

Andre G.R., Howard, R.C., Jansen, R.L., and Leone 111. K., " Evaluation of Surveillance frequencies and Out of Service Times for the Engineered Safety Features Actuation System," WCAP-10271, Supplement 2, Revision 1, March 1987.

7.

Safety Evaluation by the Office of Nuclear Reactor Regulation of WCAP-10271, Supplenent 2 and WCAP-10271 Supplenent 2, Revision 1,

" Evaluation of Surveillance Frequencies and Out of Service Times for the Engineered Safety Features Actuation System," February 22, 1989.

8.

Supplenent 1 to the February 22, 1989, Safety Evaluation by the Office of Nuclear Reactor Regulation of WCAP-10271, Supplement 2, Revision 1,

" Evaluation of Surveillance frequencies and Out of Service Times for the Engineered Safety features Actuation System," April 30, 1990.

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