ML20127F544

Application for Amend to License NPF-3 Revising Tech Spec Section 3.7.1.1 to Change Cold Shutdown (Mode 5) to Hot Shutdown (Mode 4).Safety Evaluation & Significant Hazard Consideration Encl

ML20127F544
Person / Time
Site:	Davis Besse
Issue date:	06/17/1985
From:	Crouse R TOLEDO EDISON CO.
To:
Shared Package
ML20127F511	List: ML20127F508 ML20127F544 ML20127F575
References
NUDOCS 8506250188
Download: ML20127F544 (4)

Text

. .o APPLICATION FOR AMENDMENT TO FACILITY OPERATING LICENSE NO. NPF-3 FOR DAVIS-BESSE NUCLEAR POWER STATION UNIT NO. 1 Enclosed are forty-three (43) copies of the requested changes to the Davis-Besse Nuclear Power Station Unit No. 1 Facility Operating License No. NPF-3, together with the Safety Evaluation for the requested change.

The proposed changes include Section 3.7.1.1.

By /s/ R. P. Crouse Vice President, Nuclear Sworn and subscribed before me this 17th day of June, 1985.

/s/ Laurie A. Hinkle, nee (Brudzinski)

Notary I'ublic -- State of Ohio My Commission Expires May 16, 1986.'

SEAL 8506250188 B50617 PDR ADOCK 05000346 P PDR

1 1

I Docket No. 50-346 License No. NPF-3 I

Serial No. 1159 1

June 17, 1985 1

Attachment I. Changes to Davis-Besse Nuclear Power Station Unit 1, Appendix A Technical Specifications Section 3.7.1.1 A.- Time required to Implement. This change is to be effective upon NRC approval.

B. Reason for Change (Facility Change Request 85-0051, Rev. A).

With one or more of the Code Safety Valves inoperable and if the plant is shutdown per the Action Statement per Section 3.7.1.1 it must be in Mode 5, COLD SHUTDOWN. The Applicability of the Action Statement is only MODES 1, 2 and 3, therefore, entry into Mode 5 (Cold Shutdown) should not be required.

C. Safety Evaluation (See Attached)

D. Significant Hazard Consideration (See Attached)

a SAFETY EVALUATION This FCR is to revise Tech. Spec. 3.7.1.1 action statement (change the words from " COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />" to " HOT SHUTDOWN within the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />"). This action statement concerns the Limiting Condition for Operation for the main steam line code safety valves.

The safety function of Tech. Spec. 3.7.1.1 is to ensure overpressure protection for the plant secondary side. The code safety valves are needed to relieve excess steam in the event of various transients such as, loss of load, loss of offsite power, loss of condenser vacuum, etc.

Pressure relief is required at the system design pressure of 1050 psig, and the first safety valve bank is set to relieve at this pressure.

Additional safety valve banks are set at pressures up to 1100 psig, as allowed by the ASME Code.

Existinh Tech. Spec. 3.7.1.1 action statement states that with one or more main steam line code safety valves inoperable, operation in MODES 1, 2, and 3 may proceed provided that, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, either the inoperable valve is restored to OPERABLE status or the High Flux Trip Setpoint is reduced per Table 3.7-1; otherwise, be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. In reviewing the Limiting Condition for Operation for the main steam line safety valves, it was noted that a discrepancy existed. The existing action statement for inoperable safety valves ultimately places the unit in COLD SHUTDOWN (MODE 5). However, the valves are only required to be operable in MODES 1, 2 & 3. Therefore, the action statement should require the plant to go to HOT SHUTDOWN (MODE 4).

During cooldown in MODES 1, 2, & 3 the steam generators reduce the reactor coolant system temperature from operating temperature to $ 280 F and the code safety valves must be operable to relieve potential excessive steam generation in the event of an abnormal transient. The Decay Heat Removal System (DHR) is then placed in operation when entering MODE 4 to reduce the reactor coolant temperature to the desired level. The DHR system is required to be operable in MODE 4, this includes safety relief valve DH 4849 (see Tech. Spec. 3.4.2). There is no accident initiating from MODE 4 that would require the operation of main steam code safety valves, l therefore, the safety function of Tech. Spec. 3.7.1.1 or the plant is not j being degraded by this change.

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I The-12 hour time requirement to reach the HOT SHUTDOWN condition is consistent with other Tech. Spec. (see T.S. 3.7.1.5, 3.5.2, 3.4.3) that require the plant to go to MODE 4.

l Pursuant to the above analysis, it is concluded that the change as proposed l does not degrade the safety function of this Tech. Spec. or the plant and

[ therefore, there is no unreviewed safety questions involved.

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SIGNIFICANT HAZARD CONSIDERATION The attached amendment request to revise the required Shutdown Mode per Action Statement contained within Section 3.7.1.1 from COLD SHUTDOWN to HOT SHUTDOWN does not represent a Significant Hazard Consideration.

Section 3.7.1.1 of the Davis-Besse Technical Specification requires one of the following if one or more of the code safety valves are inoperable:

a. Restore valve to OPERABIE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />,

b. Reduce High Flux Trip Setpoint per Table 3.7 (within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />),

or

c. Be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

The APPLICABILITY of this Section :- for MODES 1, 2 and 3, but the Action Statement requires the plant to be placed in MODE 5 (COLD SHUTDOWN). In MODE 4 (HOT SHUTDOWN) the Code Safety valves are not required to be ,

operable.

In MODE 4 Reactor Coolant System (RCS) temperature is between 280 and 200*F and the Decay Heat Removal (DHR) System is required OPERABLE in MODES 4, 5 and 6. The DHR system provides the decay heat removal and over pressure protection for the RCS. There is no accident in MODE 4 which requires the operation of the Code Safety Valves for mitigation of an accident.

The granting of the request would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated (10CFR50.92(C)(1)).

The changing of the Action Statement to require the plant to enter HOT STANDBY (MODE 4) and not COLD SHUTDOWN (MODE 5) will not increase the probability or consequences of an accident previously evaluated. The code safeties are not required to be OPERABLE in HOT STANDBY (MODE 4) and would not change any i accident previously evaluated.

l 2. Create the possibility of a new or different kind of accident previously evaluated (10CFR50.92(C)(2)).

I All accidents are still bounded by previous analysis and no new accidents are involved.

l 3. Involve a significant reduction in a margin of safety (10CFR50.92(C)(3)).

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This amendment request will not reduce the margin of safety assumed in the accident analysis at Davis-Besse.

l On the basis of the above, Toledo Edison has determined that the amendment request does not involve a significant hazard consideration.

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