ML18153B094

Proposed Tech Specs Surveillance Frequencies for Hydrogen Analyzers

ML18153B094
Person / Time
Site:	Surry
Issue date:	10/11/1994
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML18153B093	List: ML18153B092 ML18153B094
References
NUDOCS 9410140256
Download: ML18153B094 (6)

Text

e Attachment 2 Technical Specifications Change Surry Power Station 9410140256 941011 PDR ADOCK 05000280 P PDR

I I

TABLE 4.1-2A (CONTINUED)

MINIMUM FREQUENCY FOR EQUIPMENT TESTS UFSAR SECTION DESCRIPTION FREQUENCY REFERENCE

18. Primary Coolant System Functional 1. Periodic leakage testing(a)(b) on each valve listed in Specification 3.1.C.7a shall.be accomplished prior to entering POWER OPERATION after every time the plant is placed in COLD SHUTDOWN for refueling, after each time the plant is placed in COLD SHUTDOWN for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> if testing has not been accomplished in the preceding 9 months, and prior to returning the valve to service after maintenance, repair or replacement work is e

performed.

19. ,Containment Purge MOV Leakage Functional Semi-Annual (Unit at power or shutdown) if purge valves are operated during interva1(c)

20. Containment Hydrogen Analyzers a. CHANNEL FUNCTIONAL TEST Once per 92 days

b. CHANNEL CALIBRATION Once per 18 months

1. Sample gas used:

One volume percent

(+/-0.25%) hydrogen, balance nitrogen Four volume percent

(+/-0.25%) hydrogen, balance nitrogen

2. CHANNEL CALIBRATION will include startup and operation of the Heat Tracing System e

21. RCS Flow Flow ~ 273,000 gpm Once per refueling cycle 14

22. RWST Parameters a. Temperature~ 45°F Once per shift

b. Volume ~ 387,100 gallons Once per shift

-I

(/)

(a)

To satisfy ALARA requirements, leakage may be measured indirectly (as from the performance of pressure indicators) if accomplished in accordance with approved procedures and supported by computations showing that the method is capable of demonstrating valve

......

~

I compliance with the leakage criteria. I.C (b) a.

Minimum differential test pressure shall not be below 150 psid.

(c) Refer to Section 4.4 for acceptance criteria.

See Specification 4.1.D.

e Attachment 3 Significant Hazards Consideration Determination Surry Power Station

e e Significant Hazards Considerations As documented in NUREG-1366, "Improvements to Technical Specifications Surveillance Requirements," dated December 13, 1992, the NRC has completed a comprehensive examination of surveillance requirements in technical specifications that require testing at power. The NRC staff found that while the majority of testing at power is important, safety can be improved, equipment degradation decreased, and an unnecessary burden on personnel resources eliminated by reducing the amount of testing that is required by technical specifications at power. Generic Letter (GL) 93-05, "Line-Item Technical Specifications Improvements to Reduce Surveillance Requirements for Testing During Power Operation," dated September 27, 1993, provides guidance for preparing license amendments to implement the recommendations of NUREG-1366. Consistent with GL 93-05, we are proposing changes to the surveillance frequencies of the containment hydrogen analyzers for Surry.

NUREG-0737 required continuous indication of containment hydrogen concentration in the control room within 30 minutes of the initiation of safety injection. This indication is only used to monitor hydrogen concentration in containment following a loss-of-coolant-accident (LOCA) and to alert the plant operator to take planned manual actions to activate the hydrogen recombiners. Hydrogen recombiners are not immediately required following accident initiation. For the design basis accident (i.e., large break LOCA) they are not needed for a period of several days.

Surry has the capability to provide continuous indication in the control room of the hydrogen concentration in the containment atmosphere within 30 minutes of the initiation of safety injection. During normal plant operations, Surry maintains the analyzers in a standby mode and only fully energizes the equipment to perform the Technical Specification routine surveillance requirements. Both a monthly functional test and a quarterly calibration are performed on the hydrogen analyzers. The surveillance test history at Surry has shown that the hydrogen analyzers to be very reliable and a change in test frequency is not expected to adversely affect that experience.

Virginia Electric and Power Company has reviewed the proposed changes against the criteria of 1O CFR 50.92 and has concluded that the changes as proposed do not pose a significant hazards consideration. The proposed changes to the surveillance requirements for the hydrogen analyzers at Surry are consistent with the intent of Page 1 of 3

' . e

• Ge,neric Letter 93-05, dated September 27, 1993, which was promulgated to improve safety, decrease equipment degradation, and reduce unnecessary burden on personnel resources by reducing testing requirements that are marginal to safety. Specifically, operation of Surry Power Station in accordance with the proposed Technical Specifications changes will not:

1. Involve a significant increase in the probability of occurrence or consequences of an accident previously evaluated.

The proposed changes to the surveillance requirements for the hydrogen analyzers have no impact on the probability of any accident occurrence. The hydrogen analyzers are maintained in a standby mode during normal operation and are made fully operable within thirty minutes after a safety injection signal to provide indication of the hydrogen concentration in containment after a loss-of-coolant accident. This instrumentation is used solely post-accident to monitor containment conditions. Reduced testing of a post-accident monitor does not contribute to the probability of any previously analyzed accident. These monitors have no automatic safety function. Furthermore, the hydrogen analyzers will be operated in the same manner, and the operability requirements are not being altered. In addition, the Post-Accident Sampling System serves as a diverse means to confirm post-accident hydrogen concentration in containment.

Therefore, the consequences of a Design Basis Accident are not being increased by the proposed change in surveillance test frequency of the hydrogen analyzers.

Reducing the frequency of surveillance testing could however decrease the timeliness in identifying an inoperable hydrogen analyzer. However, our surveillance test experience has shown that the analyzers have been very stable with repeatable results, and we conclude that the change in test frequency should not affect the reliability or operability of the analyzers. Likewise, the NRC has determined in Generic Letter 93-05 that a reduced frequency of surveillance testing during power is acceptable to determine hydrogen analyzer operability.

Page 2 of 3

• , . e e

,2. Create the possibility of a new or different kind of accident from any accident previously evaluated.

There are no plant modifications or changes in methods of plant operation introduced by this change in hydrogen analyzer surveillance frequencies. The hydrogen analyzers are maintained in a standby mode during normal operation and are fully operable within thirty minutes after a safety injection signal to provide indication of the hydrogen concentration in containment after a loss-of-coolant accident. Therefore, the possibility of a new or different kind of accident than previously evaluated is not created by the proposed changes in surveillance frequency of the control rods.

3. Involve a significant reduction in a margin of safety.

The hydrogen analyzer surveillance requirements do not affect the margin of safety in that the operability requirements for the safety systems and containment remain unchanged. The hydrogen analyzers only provide indication and do not perform any direct function to mitigate the consequences of any previously analyzed accidents. Furthermore, the change in surveillance frequency is associated with a post-accident monitor with no automatic safety functions and a diverse means of confirming the parameter by the Post-Accident Sampling System. Therefore, the margin of safety is not altered by this proposed change in the surveillance frequencies of the hydrogen analyzers.

Page 3 of 3 .