ML18153C027

Proposed Tech Specs Re Containment Spray Subsystem, Containment Spray Sys & Total Sys Uncollected Leakage

ML18153C027
Person / Time
Site:	Surry
Issue date:	12/22/1989
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML18153C025	List: ML18153C024 ML18153C027
References
NUDOCS 9001020291
Download: ML18153C027 (13)

Text

e ATTACHMENT 1 Proposed Technical Specifications Change I '

Discussion The Nuclear Regulatory Commission (NRC). requested information from Virginia Electric and Power Company concerning offsite doses after a Loss-Of-Coolant Accident (LOCA) by letter, dated July 9, 1976. Additional information was requested by letter dated February 1, 1977. As a result of the above requests, the Company estimated the post LOCA normal expected leakage outside containment from the Recirculation Spray (RS) system and the Safety_ Injection (SI) system. Calculations were then performed to determine the offsite dose consequences associated with the estimated leakages. Commitments to the NRC resulted in establishing Technical Specification limits for RS and SI system leakage (Amendment Nos. 59 and 71 ).

Amendments 59 and 71 included not only the total system leakage allowed, but also included tables (Table 4.5-1 and 4.11-1). that showed how the estimated system leakages* ~were derived. Table 4.5-1 was inadvertently deleted from Technical Specifications by Amendment Nos. 128 and 128. The Technical Specification limit for RS system leakage has continued to be controlled to the total system leakage specified by Table 4.5-1.

• This proposed Technical Specification change restores the limit for RS system leakage, but does not include the table showing how the estimated system leakage was derived. Derivation of the system leakage is discussed 'in Chapter 6 of the Updated Final Safety Analysis Report (UFSAR) and need not be repeated tn the Technical Specifications. Similarly, Table 4.11-1 is being deleted from Technical, Specifications while preserving the limit for SI system leakage. For both systems, a requirement is being added to verify system leakages on a periodic basis. The basis for appropriate Technical Specifications are also being revised to state the purpose of limiting system leakages.

TS 3.3-3

10. The accumulator discharge valves listed below in non-isolated loops shall be blocked open by de-energizing the valve motor operator when the reactor coolant system pressure is greater than 1000 psig.

Unit No. 1 Unit No. 2 MOV 1865A MOV 2865A MOV 18658 MOV 28658 MOV 1865C MOV 2865C

11. Power o"peration with less than three loops in service is prohibited. The following loop isolation valves shall have AC power removed and be locked in open position during power operation.

Unit No. 1 Unit No.2 MOV 1590 MOV 2590 MOV 1591 MOV 2591 MOV 1592 MOV 2592 MOV 1593 MOV 2593 MOV 1594 MOV 2594 MOV 1595 MOV 2595

12. The total system uncollected leakage from valves, flanges, and pumps located outside containment shall not exceed the limit specified by Technical Specification 4.11.A.4.d.

TS 3.3-5

6. One charging pump component cooling water pump or one charging pump service water pump may be out of service provided the pump is restored to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

7. One charging pump intermediate seal cooler or other passive component may be out of service provided the system may still operate at 100 percent capacity and repairs are completed within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

8. Power may be restored to any valve referenced in Specifications 3.3.A.8 and 3.3.A.9 for the purpose of valve testing or maintenance provided that no more than one valve has power restored and provided that testing and maintenance is completed and power removed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

9. Power may be restored to any valve referenced in Specification 3.3.A.10 for the purpose of valve testing or maintenance provided that no more than one valve has power restored and provided that testing or maintenance is completed and power removed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

1o. The total uncollected system leakage for valves, flanges, and pumps located outside containment can exceed the limit stated in Technical Specification 4.11.A.4.d provided immediate attention is directed to making repairs and system leakage is returned to within limits within 7 days.

e TS 3.3-9 The accumulators (one for each loop) discharge into the cold leg of the reactor coolant piping when Reactor Coolant System pressure decreases below accumulator pressure, thus assuring rapid core cooling for large breaks. The line from each accumulator is provided with a motorized valve to isolate the

. accumulator during reactor start-up and shutdown to preclude the discharge of the contents of the accumulator when not required. These valves receive a signal to open when safety injection is initiated.

To assure that the accumulator valves satisfy the single failure criterion, they will be blocked open by de-energizing the valve motor operators when the reactor coolant pressure exceeds 1000 psig. The operating pressure of the Reactor Coolant System is 2235 psig and safety injection is initiated when this pressure drops to 600 psig. De-energizing the motor operator when the pressure exceeds 1000 psig allows sufficient time during. normal startup operation to perform the actions required to de-energize the valve. This procedures will assure that there is an operable flow path from each accumulator to the Reactor Coolant System during power operation and that safety injection can be accomplished.

The removal of power from the valves listed in the specification will assure that the systems of which they are a part satisfy the single failure criterion.

Total system uncollected leakage is controlled to limit offsite doses resulting from system leakage after a Loss-of-Coolant Accident.

TS 3.4-2 2,000 ppm and not greater than 2,200 ppm which will assure that the reactor is in the refueling shutdown condition when all control rod assemblies are inserted.

4. The refueling water chemical addition tank shall contain not less than 4,200 gal of solution with a sodium hydroxide concentration of not less than 17 percent by weight and not greater than 18 percent by weight.

5. All valves, piping, and interlocks associated with the above components which are required to operate under accident conditions shall be operable.

6. The total uncollected system leakage from valves, flanges, and pumps located outside containment shall not exceed the limit specified by Technical Specification 4.5.B.4.

B. During power operation the requirements of Specification 3.4-A may be modified to allow the following components to be inoperable. If the components are not restored to meet the requirements of Specification 3.4-A within the time period specified below, the reactor shall be placed in the hot shutdown condition. If the requirements of Specification 3.4-A are not satisfied within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> the reactor shall be placed in the cold shutdown condition using normal operating procedures.

e TS 3.4-3

1. One Containment Spray Subsystem may be out of service, provided immediate attention is directed to making repairs and the subsystem can be restored to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The other Containment Spray Subsystem shall be tested as specified in Specification 4.5-A to demonstrate operability prior to initiating repair of the inoperable system.

2. One outside Recirculation Spray Subsystem may be out of service provided immediate attention is directed to making repairs and the subsystem can be restored to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The other Recirculation Spray Subsystem shall be tested as specified in Specification 4.5-A to demonstrate operability prior to initiating repair of the inoperable system.

3. One inside Recirculation Spray Subsystem may be Out of service provided immediate attention is directed to making repairs and the subsystem can be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

The other Recirculation Spray Subsystem shall be tested as specified in Specification 4.5-A to demonstrate operability prior to initiating repair of the inoperable subsystems.

4. The total uncollected system leakage from valves, flanges, and pumps located outside containment can exceed the limit stated in Technical Specification 4.5.B.4 provided immediate attention is directed to making repairs and system leakage is returned to within limits within 7 days.

e TS 3.4-5 Each Recirculation Spray Subsystem draws water from the common containment sump. In each subsystem the water flows through a recirculation spray pump and recirculation spray cooler, and is sprayed into the containment atmosphere through a separate set of spray nozzles. Two of the recirculation spray pumps are located inside the containment and two outside the containment in the containment auxiliary structure.

With one Containment Spray Subsystem and two Recirculation Spray Subsystems operating together, the Spray Systems are capable of cooling and depressurizing the containment to subatmospheric pressure in less than 60 minutes following the Design Basis Accident. The Recirculation Spray Subsystems are capable of maintaining subatmospheric pressure in the containment indefinitely following the Design Basis Accident when used in conjunction with the Containment Vacuum System to remove any long term air in leakage.

In addition to supplying water to the Containment Spray System, the refueling water storage tank is also a source of water for safety injection following an accident. This water is borated to a concentration which assures reactor shutdown by approximately 1O percent t:\k/k when all control rod assemblies are inserted and when the reactor is cooled down for refueling.

Total system uncollected leakage is controlled to limit offsite doses resulting from system leakage after a Loss-of-Coolant Accident.

e e TS 4.5-2

2. By verifying that each motor-operated valve in the recirculation spray flow paths performs satisfactorily when tested in accordance with Specification 4.0.3.

3. At least once per 5 years, coincident with the closest refueling outage, by performing an air or ~make flow test and verifying each spray nozzle is unobstructed.

4. At least once each refueling outage by verifying that total system uncollected leakage from valves, flanges, and pumps located outside containment does not exceed 964 cc/hr.

C. Each weight-loaded check valve in the containment spray and outside containment recirculation spray subsystems shall be demonstrated operable at least once per 18 months, during shutdown, by cycling the valve one complete cycle of full travel and verifying that each valve opens when the discharge line of the pump is pressurized with air and seats when a vacuum is applied.

D. A visual inspection of the containment sump and the inside containment recirculation spray pump wells and the engineered safeguards suction inlets shall be performed at least once each refueling period and/or after major maintenance activities in the containment. The inspection should verify that the containment sump and pump wells are free of debris that could degrade system operation and that the sump components (i.e.,

trash racks, screens) are properly installed and show no sign of structural distress or excessive corrosion.

Basis The flow testing of each containment spray pump is performed by opening the normally closed valve in the containment spray pump recirculation line returning water to the refueling water storage tank. The containment spray pump is operated and a quantity of water recirculated to the refueling water storage tank. The discharge to the tank is divided into two fractions; one for the major portion of the recirculation flow and the other to pass a small quantity of water through test nozzles which are identical with those used in the containment spray headers. The purpose of the recirculation through the test nozzles is to assure that there are no particulate material in the refueling water storage tank small enough to pass throug~ pump suction strainers and large enough to clog spray nozzles.

e TS 4.11-2

c. Verifying, by visual inspection, that each low head safety injection pump suction inlet from the containment sump is free of debris that could degrade system operation. Perform each refueling outage and/or after major maintenance activities in the containment.

d. Verifying that total system uncollected leakage from valves, flanges, and pumps located outside containment does not exceed 3,836 cc/hr.

Complete system tests cannot be performed when the reactor is operating because a safety injection signal causes containment isolation. The method of assuring operability of these systems is therefore to combine system tests to be performed during refueling shutdowns, with more frequent component tests, which can be performed during reactor operation.

The system tests demonstrate proper automatic operation of the Safety Injection System. A test signal is applied to initiate automatic operation action and verification is made that the components receive the safety injection signal in the proper sequence. The test may be performed with the pumps blocked from starting. The test demonstrates the operation of the valves, pump circuit breakers, and automatic circuitry.

During reactor operation, the instrumentation which is depended on to initiate safety injection is checked periodically, and the initiating circuits are tested in accordance with Specification 4.1. In addition, the active components (pumps and valves) are to be periodically tested to check the operation of the starting circuits and to verify that the pumps are in satisfactory running order. The test interval is determined in accordance with ASME Section XI. The accumulators are a passive safeguard. In accordance with Specification 4.1, the water volume and pressure in the accumulators are checked periodically.

References FSAR Section 6.2, Safety Injection System

.. ~

e TS 4.11-3 THE INFORMATION ON TS PAGES 4.11-3 THROUGH 4.11-5 HAS BEEN DELETED *I

. .. e e ATTACHMENT 2 Significant Hazards Consideration

Significant Hazards Consideration The proposed change to restore total RS system leakage limitations and delete Table 4.11-1 from Technical Specifications does not result in a significant hazards consideration per 10 CFR 50.92.

1. The proposed change does not significantly increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report. The proposed specification limits total RS and SI system leakages to values consistent with the assumed values in existing accident analysis. Subsystem and component specific contributions to the total system leakage have no effect on accident assumptions or UFSAR identified accident consequences. Total system leakage limits ensure that accident consequences are limited to evaluated consequences, and do not affect the probability of accident occurrence. The proposed change is administrative in nature and does not affect any system or equipment or its respective operation. The RS system leakage limit inadvertently deleted by Amendment Nos. 128 and 128 is being restored, however, Table 4.5-1 showing how the estimated leakage was calculated will remain deleted. Similarly, Table 4.11-1 is being deleted for the SI system while maintaining the total SI system leakage limit. The added requirement to periodically verify system uncollected leakage represents an additional restriction since no previous requirement existed.

2. The proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated. As noted above, only total RS and SI system leakage is considered in the safety analysis. Removing subsystem or component specific estimated contributions from the total leakage specification has no impact on accident consideration. No change is being made to the station or its operating procedures.

3. The proposed amendment does not involve a significant reduction in a margin of safety. Total leakage is being controlled to the same limits that previously existed. Thus, offsite dose consequences remain unchanged.