ML20117F946

Proposed Tech Specs Requiring That Acoustic Monitoring Sys Be Considered as One of Two Required Valve Position Indication Channels for Pressurizer PORVs & Safety Valves

ML20117F946
Person / Time
Site:	Sequoyah
Issue date:	05/06/1985
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20117F939	List: ML20117F935 ML20117F946
References
NUDOCS 8505130367
Download: ML20117F946 (8)

Text

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@O ACCIDENT HONITORING INSTRUMENTATION E_ HINIHUM

' REQUIRED HO CHANNELS OF CHANNELS OPERABLE E INSTRUMENT

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2 1

- 1. Reactor Coolant THot (Wide Range) 2 1

2. Peactor Coolant TCold (Wide Range) 1 2

3. Containment Pressure 1

2 m

4. Refueling Water Storage Tank Level 1

2

5. Reactor Coolant Pressure 2 I

6. Pressurizer Level (Wide Range) s 1/ steam line 2/ steam line

[. 7. ' Steam Line Pressure 1/ steam generator 1/ steam generator E 8. Steam Generator Level - Wide 1/ steam generator 1/ steam generator

9. Steam Gensrator Level - Narrow 1/ pump 1/ pump

10. Auxiliary Feedwater flow Rate 0

11. Reactor Coolant System S6bcooling Margin Monitor 1 2/ valve # 1/ valve

12. Pressurizer PORV Position Indicator

• 2/ valve 1/ valve

- 13. Pressurizer PORV Block Valve Position Indicator **

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2/va1veg 1/ valve

14. Safety Valve Position Indicator 1

15. Containment Water level (Vide Range) I (. 2 4/ core quadrant 2/ core quadrant

'6. In Core Thermocouples g5130 gggggg27 p PDR

'Not applicable if the associatea plock valve is in the closed position.

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T r-INSTRUMENTATION BASES Sequoyah has four separate methods of determining safety valve position

.(i.e., open or closed).

a. Acoustic flow monitors mounted on each safety valve line (one per :

valve). A flow indicating module in the main control room is calibrated to detect failure of a valve to reclose. An alarm in the.

main control room will actuate when any valve is not fully closed.

b. -Temperature sensors downstream of each safety valve (one per valve).

Temperature indication and alarm are provided in the main control-room.

c. Pressurizer relief tank temperature, pressure and level indication, and alarm in main control room,

d. Pressurizer pressure indication and alarm in the main control room.

Although all the above position indicators for the pressurizer safety valves and the PORVs are acceptable as one of the channels, the acoustic monitors must be one of the two required operable chanels. In addition

- to the four methods described above, the PORVs use an electromagnetic

" reed"-switch to determine valve position. The stem mounted switches are no longer in use since the PORVs were changed.

SEQUOYAH - UNIT 1 B 3/4 3-3a

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e PROPOSED GANGES UNIT 2 l

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t-ACCIDENT .sRING INSTRUMENTATIO'. ,

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= MINIMUM REQUIRED NO. CHANNELS OF CHANNELS OPERABLE 5

INSTRUMENT 2 1

^2 1. Reactor Coolant THot (Wide Range)

2. Reactor Coolant TCold ( ' ' '"9')

2 1

3. Containment Pressure 1

4. Refueling Water Storage Tank Level , .2 2 1

5. Reactor Coolant Pressure 1

6. Pressurizer Level (Wide Range) 2 M 2/ steam line 1/ steam line em 7. Steam Line Pressure Steam Generator Level - (Wide Range) 1/ steam generator 1/ steam generator

8.

Steam Generator Level - (Harrow Range) 1/ steam generator 1/ steam generator 9.

1/ pump 1/ pump

10. Auxiliary Feedwater Flow Rate Reactor Coolant Systeh Subcooling Margin Monitor 1 0 11.

12. Pressurizer PORV Position Indicator

• 2/ valve'W6 1/ valve

13. Pressurizer PORV Block Valve Position Indicator ** 2/ valve 1/ valve

14. Safety Valve Position Indicator 2/ valve g$F 1/ valve Containment Water Level (Wide Range) 2 1 15.

J.e. 2/ core quadrant

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16. In Core Thermocouples 4/ core quadrant.

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• Not applicable if the associated block valve is in the closed position.

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• • Not applicable if the block valve is verified in the closed position with power to the valve

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-INSTRUMENTATION 8ASES 3/4.3.3.4 METEOROLOGICAL INSTRUMENTATION The OPERABILITY of the meteorological instrumentation ensures that sufficient meteorological data ia available for estimating potential radiation doses to the public as a result of routine or accidental release of radioactive materials to the atmosphere. This capability is required to evaluate the need-for initiating protective measures to ptotect the health hnd safety of the gublic.andisconsistentwiththerecommendationsofRegulatoryGuide1.23, Onsite Meteorological Programs," February 1972.

3/4.3.3.5 REMOTE SHUTDOWN INSTRUMENTATION The OPERABILITY of the remote shutdown instrumentation ensures that sufficient capability is available to permit shutdown and maintenance of HOT STAN0BY of the facility from locations outside of the control room. This capability is required in the event control room habitability is lost and is consistent with General Design Criteria 19 of 10 CFR 50.

3/4.3.3.6 CHLORINE DETECTION SYSTEMS The OPERABILITY of the chlorine detection system ensures that sufficient capability -is available to promptly detect and initiate protective action in the event of an accidental chlorine release. This capability is required to protect control room personnel and is consistent with the recommendations of Regulatory Guide 1.95, " Protection of Nuclear Power Plant Control Room Operators Against an Accidental Chlorine Release," February 1975.

3/4.3.3.7 A'CCIDENT MONITORING INSTRUMENTATION The OPERABILITY of the accident monitoring instrumentation ensures that sufficient information is available on selected plant parameters to monitor and ascess these variables following an accident. This capability is consistent with the recommendations of Regulatory Guide 1.97, " Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident," December 1975.

' Sequoyah has four separate me thods of determining safety valve position (i.e., open or closed).

a. Acoustic flow monitors mounted on each safety valve line (one

.per valve). A flow indicating module in the main control room is calibrated to detect failure.of a valve to reclose. An alarm in the main control room will actuate when any valve is not fully closed.

b. Temperature sensors downstream of each safety valve (one per valve). Temperature indication and alarm are provided in the main control room.

c. Pressurizer relief tank temperature, pressure and level indi. cation, and alarm in main control room.

d. Pressurizer pressure indication and alarm in the main control room.

I-i SEQUOYAH - UNIT 2 8 3/4 3-3

3 i .

INSTRUMENTATION BASES _.

Although all the above position indicators for the pressurizer safety valves and the PORVs are acceptable as one of the channels, the acoustic monitors must be one of the two required operable chanels. In addition to the four methods described above, the PORVs use an electromagnetic

" reed"-switch to determine valve position. The stem mounted switches are no longer in use since the PORVs were changed.

3/4.3.3.8 FIRE DETECTION INSTRUMENTATION OPERABILITY of the fire detection instrumentation ensures that adequate warning capability is available for the prompt detection of fires. This capability is required in order to detect and locate fires in their early stages. Prompt detection of fires will reduce the potential for damage to safety related equipment and is an integral element in the overall facility fire protection program.

In the event that a portion of the fire detection instrumentation is inoperable, the establishment of frequent fire patrols in the affected areas is required to provide detection capability until the inc?erable instrumentation is restored to OPERABILITY.

3/4.3.3.7 RADIOACTIVE LIQUID EFFLUENT INSTRUMENTATION

- " The~ radioactive liquid effluent instrumentation is provided to monitor and control, as applicable, the releases of r^dioactive materials in liquid effuents during actual or potential releases of liquid effluents. The alarm /

trip setpoints for these instruments shall be calculated in accordance with the procedures in the ODCM to ensure that the alarm / trip will occur prior to exceeding the limits of 10 CFR Part 20. The OPERABILITY and use of this instrumentation is consistent with the requireinents of General Design Criteria _60, 63..and 44 of. Appendix. A_to_10 CFR Part 50.

3/4.3.3.8 RADI0 ACTIVE GASEOUS EFFLUENT INSTRUMENTATION The radioactive gaseous effluent instrumentation is provided to monitor and control, as applicable, the releases of radioactive materials in gaseous effluents during actual or potential releases of gaseous effluents. The alarm / trip setpoints for these instruments shall be calculated in accordance with the procedures.. in the ODCM to. ensure that the alarm / trip will occur prior to exceeding the limits of 10 CFR Part 20. This instrumentation also includes provisions for monitoring the concentrations of potentially explosive gas mixtures in the waste gas holdup system. The OPERABILITY and use of this instrumentation is consistent with the requirements of General Design Criteria 60, 63 and 64 of Appendix A to 10 CFR Part 50.

8 3/4 3-4 SEQUOYAH - UNIT 2

IS ENCLOSURE 2 JUSTIFICATION FOR PROPOSED CHANGE IN TECHNICAL SPECIFICATIONS FOR UNITS 1 AND 2 SEQUOYAH NUCLEAR PLANT This change will revise LCO 3 3 3 7, table 3 3-10, items 12 and 14 for both units to require the acoustic flow monitors to be one of the two required position indication channels for the pressurizer safety valves and power operated relief valves. Also, the BASES statements for B 3/4 3 3 7 are revised for both units to provide further clarification for the requirements.

This change is being submitted as a result of a commitment to NRC OIE to resolve NRC concerns addressed in NRC-0IE Inspection Report 50-327/83-26 and 50-328/83-26 for Sequoyah. The commitment was submitted to NRC by the September 21, 1984 letter from L. M. Mills to J. P. O'Reilly. The significant hazards consideration detenmination is provided in attachment 1 and in accordance with our evaluation pursuant to 10 CFR 50.92, no significant hazaros considerations are involved.

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e-ATTACHMENT 1

-PROPOSED TECHNICAL SPECIFICATION CHANGES SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION (TVA SQN TS 63) 1.- Is the probability of an occurrence or the consequences of an accident previously evaluated in the safety analysis report significantly

. increased? No.

2.. Is the possibility for an accident of a new or different type th'an evaluated previously in the safety analysis report created? No..

3 Is the margin of safety significantly reduced? No.

For_each of the items above, the' evaluation resulte'd in a negative response since this change makes the limiting condition for operation more restrictive by requiring the. acoustic monitoring system to be considered as one of the two required channels of valve position indication. This change is being made as requested by NRC-0IE to resolve NRC concerns resulting fram an inspection of Sequoyah and documented in OIE Inspection Report 50-327/83-26 and 50-328/83-26.