ML20245A292

Application for Amend to License NPF-3,revising Tech Specs to Clarify That DHR Valve DH23 Not Required to Be Subj to Type C Test Requirements Since Valve Normally Closed & Manually Operated

ML20245A292
Person / Time
Site:	Davis Besse
Issue date:	06/13/1989
From:	Shelton D TOLEDO EDISON CO.
To:
Shared Package
ML20245A227	List: ML20245A225 ML20245A292 ML20245A294
References
NUDOCS 8906210191
Download: ML20245A292 (6)

Text

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.' 'Dopket Number 50-346 License Number NPF-3 Serial Number 1667 Enclosure Page 1 APPLICATION FOR A!!ENDMENT TO FACILITY OPERATING LICENSE NUMBER NPF-3 DAVIS-BESSE. NUCLEAR POWER STATION UNIT NUMBER 1 Attached is a requested change to the Davis-Besse Nuclear Power Station, Unit Number 1 Facility Operating License Number NPF-3. Also included are the Technical Description and Significant Hazards Consideration..

The proposed change (submitted under cover letter Serial Number 1667) concerns:

Section 3/4.6.3.1, Containment Isolation Valves, Table 3.6-2, Valve DH23.

1 By:

D. Of Shelton, Vice President, Nuclear D

Svorn and subscribed before me this 13th day of June, 1979.

_ LLk L L LL D N6tdry Public, State of Ohio  ;

l LAURIE A. HINKLE tict:ty Pebli::. State of Ohto f.tfCommission Expires !.hy 15.1991  ;

l 8906210191 S90613 PDR ADOCK 05000346 P PDC

9

. ' Docket Number 50-346 License Number NPF-3 Serial Number 1667 Enclosure Page 2 The following information is provided to support issuance of the requested change to the Davis-Besse Nuclear Power Station, Unit Number 1 Operating License Number NPF-3, Appendix A, Technical Specification, Section 3/4.6.3.1, Table 3.6-2.

A. Time Required to Implement: This change is to be implemented within 45 days after the NRC issuance of the License Amendment.

B. Reason for Change (License Amendment Request Number 88-0020):

This request proposes to apply an existing Table 3.6-2 fcotnote to decay heat removal valve DH23 vhich will clarify that the valve is not subject to 10CFR50, Appendix J, Type C testing. Valve DH23 is a normally locked closed, manually operated containment isolation valve, located inside the containment vessel in series with valve DH21 (also normally closed) in the bypass line around valves DH11 and DH12, decay heat pump suction isolation valves. Type C testing of valve DH23 is not required since the valve does not meet the criteria which requires Type C testing.

C. Technical

Description:

See attached Technical Description (Attachment 1).

D. Significant Hazards Consideration: See attached Significant Hazards Consideration (Attachment 2).

l I l I

. ' Docket' Number 50-346 License Number NPF-3 Serial Number 1667 Attachment 1 Page 1 TECHNICAL DESCRIPTION Description of Proposed Technical Specification Change The purpose of this Technical Description is to review a proposed change to the Davis-Besse Nuclear Power Station Technical Specification (TS) 3/4.6.3.1, Containment Isolation Valves, Table 3.6-2. This request proposes to apply an existing Table 3.6-2 footnote to decay heat removal valve DH23 which will clarify that the valve is not subject to 10CFR50, Appendix J, Type C testing.

Valve DH 23 is a normally locked closed, manually operated containment isolation valve, located inside the containment vessel in series with valve DH21 (also normally closed) in the bypass line around valves DH11 and DH12, decay heat pump suction isolation valves. Type C testing of valve DH23 is not required since the valve does not meet the criteria which requires Type C testing.

Systems Affected Decay Heat Removal (no hardware changes)

Safety Function of System Affected The decay heat removal (DHR) system removes decay heat from the core and sensible heat from the reactor coolant system (RCS) during the later stages of cooldown. The system also provides auxiliary spray to the pressurizer for complete depressurization, maintains the reactor coolant temperature during refueling, and provides for a means of filling and partial draining of the refueling canal. The decay heat pump suction line is normally closed when the unit is in operation, but is used post-loss-of-coolant-acciacat (LOCA) for boron dilution, thereby providing an engineered safety feature function.

Valve DH23 is a normally locked closed, manually operated containment isolation valve, located inside the containment vessel in series with valve DH21 (also normally closed) in the bypass line around valves DH11 and DH12, decay heat pump suction isolation valves (see attached figure). Valve DH23 is required to be closed when the unit is operating in Modes 1 and 2 providing a pressure boundary between the RCS and the DHR system and providing a normally locked closed passive barrier in the event of a design basis accident. In Modes 4 and 5, in order to provide continuous RCS lov temperature overpressure protection, Technical Specification 3.4.2 (Safety Valves - Shutdown) requires valves DH21 and DH23 to be open when either valve DH11 or DH22 is closed.

Valves DH21 and DH23 are also open when either valve DH11 or DH12 is closed to provide a flow path from the RCS to the DHR system to maintain the > 2800 gpm flow rate of reactor coolant through the RCS per Technical Specification 3.1.1.2 (Reactivity Control Systems - Boron Dilution), provide a flow path for normal decay heat removal with the unit in Modes 3, 4, and 5 per Technical Specification 3.4.1.2 (Reactor Coolant System - Shutdown and Hot Standby), and maintain a flow rate of reactor coolant through the RCS when the unit is in Mode 6 per Technical Specifications 3.9.8.1 (Refueling Operations - Decay Heat Removal and Coolant Circulation - All Vater Levels) and 3.9.8.2 (Refueling Operations - Decay Heat Removal and Coolant Circulation - Lov Vater Levels).  ;

Valve DH11 is also not subject to Type C testing and the subject footnote is applicable to its entry in the Table.

' Docket Number 50-346

- License Number HPF-3 Serial Number 1667 Attachment 1 Page 2 Effects on Safety / Proposed Change

~

10CFR50, Appendix J Type C Tests are intended to measure _ leakage rates for containment isolation valves that:

1. Provide a direct connection between the inside and outside atmospheres of the primary reactor containment under normal operation, such as purge _and ventilation, vacuum relief, and instrument valves;

2. Are required to close automatically upon receipt of a containment isolation signal in response to controls intended to effect containment isolation;

3. Are required to operate intermittently under post-accident conditions; and

4. Are in main steam and feedvater piping and other systems which penetrate containment of direct-cycle boiling water power reactors.

Valve DH23 does not meet any of the above criteria. Valve DH23'is a normally locked-closed, manually operated containment isolation valve, located inside the containment vessel in series with valve DH21 (also normally closed)_in the bypass line around valves DHil and DH12, decay heat pump suction isolation valves. The decay heat pump suction line is normally closed when the unit is in operation, but is used post-loss-of-coalant-accident (LOCA) for boron dilution, thereby providing an engineered safety feature function. Tnis line forms a closed loop outside the containment and terminates inside the containment vessel. All components of the closed loop system are Class 2,.

designed and analyzed as seismic Class I. At all times, after a LOCA, there is a water seal from either the BWST or upon recirculation, the emergency sump. Since valve DH23 is manually operated and is located inside the containment, this valve is not expected to be used during post-accident conditions. Post-accident-functions are provided by valves DHil and DH12 which are in the parallel flow path. The proposed change is for clarification purposes only and has no effect on the function of the valve, other systems or other components.

Unreviewed Safety Question Evaluation Toledo Edison has performed a safety review and evaluation for this proposed change and reached the following conclusions concerning an.unreviewed safety question:

l The proposr

• sction vould not increase the probability of' an' accident previously evaluated in the USAR because no ' operating requirements of DH23 at e changed.

The proposed action vould not increase the consequences of.an accident previously evaluated in the USAR because no operating requirements of DH23 are changed. As a containme".t integrity boundary, any potential leakage past DH23 would be contained in the closed loop system.

1

' Docket Number 50-346 '

License Number NPP-3 Serial Number 1667 Attachtrent 1 i Page 3 The proposed action would not increase the probability of a malfunction of equipment important to safety because no operating requirements of Dil23 are changed.

The proposed action would not increase the consequences of a malfunction of equipment important to safety because no operating requirements of Dil23 are changed. I l

The proposed action would not create a possibility for an accident of a different type than any evaluated previously in the USAR because no operating requirements of Dil23 are changed. 1 The proposed action vould not create a possibility for a malfunction of equipment of a different type thn any evaluated previously in the USAR because no operating requirement of D1123 are changed.

The proposed action would not reduce any margin of safety as defined in the i basis for any Technical Specification because no operating requirements of D1123 are changed and the containment integrity function is not changed. Any potential leakage past Dil23 would be contained in the closed loop system.

Conclusion Based on the above, it is concluded that the proposed Technical Specification change does not constitute an unreviewed safety question. I i

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