ML18153B350

Proposed Tech Specs for RSHX Svc Water Outlet Radiation Monitors

ML18153B350
Person / Time
Site:	Surry
Issue date:	10/19/1993
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML18153B349	List: ML18153B348 ML18153B350
References
NUDOCS 9310260055
Download: ML18153B350 (10)

Text

TS 3.7-7 steam line pressure setting limit is set below the full load operating pressure. The safety analysis shows that these settings provide protection in the event of a large steam line break. (3)

Accident Monitoring Instrumentation The operability of the accident monitoring instrumentation in Table 3. 7-6 ensures that sufficient information is available on selected plant parameters to monitor and assess these variables during and following an accident. On the pressurizer PORVs, the pertinent channels consist of redundant limit switch indication. The pressurizer safety valves utilize an acoustic monitor channel and a downstream high temperature indication channel. 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, and NUREG-0578, "TMl-2 Lessons Learned Task Force Status Report and Short Term Recommendations." Potential gaseous effluent release paths are equipped with radiation monitors to detect and measure concentrations of noble gas fission products in plant gaseous effluents during and following an accident.

The gaseous effluent release paths monitored are the process vent stack, ventilation vent stack, main steam safety valve and atmospheric dump valve discharge and the AFW pump turbine exhaust. The potential liquid effluent release paths via the service water discharge from the recirculation spray heat exchangers are equipped with radiation monitors to detect leakage of recirculated containment sump fluid. These radiation monitors and the associated sample pumps are required to operate during the recirculation heat removal phase following a loss of coolant accident in order to detect a passive failure of a recirculation spray heat exchanger tube. These monitors meet the requirem~nts of NUREG-0737.

Instrumentation is provided for monitoring (and controlling) 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.

Containment Hydrogen Analyzers Indication of hydrogen concentration in the ~ontainment atmosphere is provided in the control room over the range of zero to ten percent hydrogen concentration.

( 9310260055 931019 PDR ADOCK 05000280 P PDR Amendment Nos.

TABLE 3.7-6 ACCIDENT MONITORING INSTRUMENTATION Instrument Total No. Of Channels Minimum OPERABLE Channels

1. Auxiliary Feedwater Flow Rate 1 per S/G 1 per S/G

2. Inadequate Core Cooling Monitor

a. Reactor Vessel Coolant Level Monitor 2 1

b. Reactor Coolant System Subcooling Margin Monitor C. Core Exit Thermocouples 2

2 (Note 2) 1 1 (Note 2) e

3. PORV Position Indicator 1/valve 1/valve

4. PORV Block Valve Position Indicator 1/valve 1/valve

5. Safety Valve Position Indicator (Primary Detector) 1/valve 1/valve

6. Safety Valve Position Indicator (Backup Detector) 1/valve 0

7. Containment Pressure 2 1

8. Containment Water Level (Narrow Range) 2 1

9. Containment Water Level (Wide Range) 2 1

)> 10. Containment High Range Radiation Monitor 2 1 (Note 1, b and c only) 3 CD

J

11. Process Vent High Range Effluent Monitor 2 2 (Note 1, a, b, and c)

C.

3 12. Ventilation Vent High Range Effluent Monitor 2 2 (Note 1, a, b, and c)

-z CD

J

13. Main Steam High Range Radiation Monitors (Units 1 and 2) 3 3 (Note 1, a, b, and c) 0

~ 14. Aux. Feed Pump Steam Turbine Exhaust Radiation Monitor 1 1 (Note 1, a, b, and c)

15. Recirculation Spray Heat Exchanger Service Water Outlet Radiation Monitor 1 perRSHX 1 per RSHX (Note 1, a, b, and c)

Note 1: With the number of operable channels less than required by the Minimum OPERABLE Channels requirements

a. Initiate the preplanned alternate method of monitoring the appropriate parameter(s), within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> --i

b. Either restore the inoperable channel to operable status within 7 days of the event, or en

c. Prepare and submit a Special Report to the commission pursuant to specification 6.2 within 30 days following the event u) outlining the action taken, the cause of the inoperability and the plans and schedule for restoring the system to operable. -.J I

Note 2: A minimum of 2 core exit thermocouples per quadrant are required for the channel to be operable. I\)

co

TABLE 4.1-2 ACCIDENT MONITORING INSTRUMENTATION SURVEILLANCE REQUIREMENTS CHANNEL CHANNEL FUNCTIONAL CHANNEL INSTRUMENT CHECK TEST CALIBRATION

1. Auxiliary Feedwater Flow Rate p R

2. Inadequate Core Cooling Monitor M R

3. PORV Position Indicator (Primary Detector) M R

4. PORV Position Indicator (Backup Detector) M R

5. PORV Block Valve Position Indicator M R

6. Safety Valve Position Indicator M R

7. Safety Valve Position Indicator (Backup Detector) M R

8. Containment Pressure M R

9. Containment Water Level (Narrow Range) M R

10. Containment Water Level (Wide Range) M R

)> 11. Containment High Range Radiation Monitor M a R 3

CD

J

12. Process Vent High Range Effluent Monitor M a R

a. 13. Ventilation Vent High Range Effluent Monitor M a R 3

-z CD

J 14. Main Steam High Range Radiation Monitor M a R 0

15. Auxiliary Feedwater Pump Turbine Exhaust Radiation Monitor M a R en

16. Recirculation Spray Heat Exchanger Service Water Outlet M _0(1) R Radiation Monitors (1) Channel Functional testing shall include the associated sample pump.

M - Monthly P - Prior to each startup if not done within the previous week a - Quarterly ......

I R - Refueling <.O ll)

_J

ATTACHMENT 2 DISCUSSION AND SIGNIFICANT HAZARDS CONSIDERATION EVALUATION SURRY POWER STATION

Discussion of Changes Introduction The Recirculation Spray Heat Exchanger (RSHX) service water outlet radiation monitors do not have specific operability or surveillance requirements identified in the Technical Specifications (TS). These radiation monitors serve as accident monitoring instruments. Their function is to detect a breach of a barrier to fission product release.

This position is consistent with their classification as Regulatory Guide 1.97 Type C, Category 2 instrumentation. These radiation monitors are being added to Technical Specifications. In addition, surveillance requirements for several Post Accident Instruments are being reinstated into Technical Specifications.

Background

During a design basis event, heat is removed from the containment by four recirculation spray heat exchangers per unit that are located inside containment. The RSHXs are cooled by the Service Water System. The service water outlet of each RSHX is provided with a RSHX service water outlet radiation monitor to detect leakage of radioactive containment sump fluid into the Service Water System if there is a breach in RSHX integrity. There are eight (four per Unit) Recirculation Spray Heat Exchanger service water outlet radiation monitors. Eight sample pumps (four per unit, one per RSHX) draw samples from the service water discharge piping of the RSHXs and provide them to the radiation monitors for analysis. The potential source of radioactivity that the monitors would sense is from a breach of RSHX integrity.

Therefore, these monitors are used to identify a breach of a fission product barrier.

Operation of these monitors is not required in order for the Recirculation Spray System or the Service Water System to accomplish their safety-related functional requirements. The radiation monitors for the affected unit are located in the opposite unit's Safeguards building. This precludes these radiation monitors from being subjected to the radiation emanating from the affected unit during a design basis LOCA. The sample pumps are located in the affected unit and are subject to the potential radiation source from that unit. These pumps are designed to be safety-related. The power supplies for the radiation monitors and sample pumps are provided from 480 volt emergency bus motor control centers.

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e The radiation monitors provide indication only. This output is displayed on the individual ratemeters and recorded on the radiation monitoring panel recorders in the Main Control Room. The ratemeter output is also provided to the Emergency Response Facility computer. These radiation monitors do not provide a protection or control function. However, there are Main Control Room alarms and annunciators associated with the monitors allowing for appropriate operator action to isolate the potential release path. Service water flow to the leaking RSHX would be isolated by closing the associated Service Water System motor-operated isolation valves from the Main Control Room.

Operability requirements for post-accident radiation monitors were added to the Technical Specifications by License Amendments 100 and 99, dated October 15, 1984, for Surry Power Station Units 1 and 2, respectively. Specifically, the following monitors were added to TS Table 3. 7-6: (1) Containment High Range Radiation Monitor, (2) Process Vent High Range Effluent Monitor, (3) Ventilation Vent High Range Effluent Monitor, (4) Main Steam High Range Radiation Monitor, and (5)

Auxiliary Feedwater Pump Steam Turbine Exhaust Radiation Monitor. However, surveillance requirements for these monitors were not added as new items by Amendments 100 and 99, since TS Table 4.1-1 already specified surveillance requirements for "Process and Effluent Radiation Monitoring Systems." These surveillance requirements were incorporated as part of the Radioactive Effluent Technical Specifications (RETS) change, Amendments 97 and 96 for Units 1 and 2 respectively. Subsequently, Amendments 155 and 154 for Units 1 and 2 respectively, removed the RETS program from Technical Specifications. The post-accident radiation surveillance requirements were inadvertently deleted from Technical Specifications when the RETS were removed in Amendments 155 and 154.

Specific Changes Operability requirements and action statements for the RSHX service water outlet radiation monitors are being added to TS Table 3.7-6, consistent with their Post Accident Monitoring function. Likewise, surveillance requirements for these monitors will be added to TS Table 4.1-2.

The basis section of TS 3.7 is revised to describe the function and requirements for operation of the RSHX service water outlet radiation monitors. The monitors and Page 2 of 6

associated sample pumps are required to operate during the recirculation heat removal phase following a LOCA to detect a breach (passive failure) of RSHX integrity.

Surveillance requirements for the post-accident radiation monitors noted above are being specified as individual line items for each monitor in TS Table 4.1-2. The surveillance tests and frequencies are unchanged from the previous requirements.

Safety Significance Addition of Recirculation Spray Heat Exchanger Service Water Outlet Radiation Monitors to the Accident Monitoring Instrumentation Technical Specifications The RSHX service water outlet radiation monitors are provided to detect a passive failure involving a loss of integrity of a RSHX during the recirculation heat removal phase following a design basis LOCA. These monitors do not provide a protection or control function and are not required in order for the Recirculation Spray System or Service Water System to accomplish their safety-related functional requirements. The RSHX service water outlet radiation monitors are classified as Regulatory Guide 1.97, Type C, Category 2 instruments. Type C variables are those which provide information to indicate the potential for being breached or the actual breach of the barriers to fission product releases. As such, the RSHX service water outlet radiation monitors are classified as accident monitoring instruments.

The Recirculation Spray System, in conjunction with the Containment Spray System, has the following safety-related functional requirements: (1) ensure the integrity of the containment following an accidental release of high-energy fluids inside containment by maintaining containment. pressure at values less than the containment design pressure; (2) minimize containment leakage following an accidental release of high-energy fluids inside containment by rapidly cooling and depressurizing the containment structure to subatmospheric conditions; (3) reduce the concentration of radioactive iodine in containment atmosphere following an accidental release of high-energy fluids inside containment so that the site boundary dose from any outleakage prior to the containment becoming subatmospheric is within the guidelines of 10 CFR 100.

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• Operation of the RSHX service water outlet radiation monitors is not required to satisfy these safety-related functional requirements. The function of the RSHX service water outlet radiation monitors is not required to satisfy the system safety function of the Recirculation Spray System or the Service Water System. The operability of these monitors is not required for recirculation spray heat exchanger operability.

The RSHX service water outlet radiation monitors are provided to detect a passive failure involving a loss of integrity of a RSHX during the recirculation heat removal phase of a design basis LOCA. These monitors perform a function similar to that of other effluent monitors, which are not considered to be supporting systems for the systems from which a radioactive release is postulated to occur.

Addition of Surveillance Reguirements for Post-Accident Radiation Monitors This change is administrative in nature, serving to reinstate surveillance requirements for accident monitoring instruments into TS that were inadvertently relocated when Radioactive Effluent Technical Specifications were moved to the Offsite Dose Calculation Manual (ODCM). Procedures have remained in place and the surveillances have been performed throughout this period.

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Significant Hazards Considerations Virginia Electric and Power Company has reviewed the proposed changes against the criteria of 10 CFR 50.92 and has concluded that the changes as proposed do not pose a significant hazards consideration. Specifically, operation of Surry Power Station in accordance with the proposed Technical Specification changes will not:

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

The RSHX service water outlet radiation monitors and the post-accident radiation monitors are not involved in the initiation of any previously evaluated accidents. The probability of occurrence of such accidents is, therefore, not increased. The RSHX service water outlet radiation monitors will be required to be operable as accident monitoring instruments and will be available following a LOCA to detect radioactive leakage into the Service Water System. During a design basis event, heat is removed from the containment by the recirculation spray heat exchangers (RSHXs). The RSHXs are cooled by the Service Water System. The service water outlet of each RSHX is provided with a radiation monitor to detect leakage of radioactive containment sump fluid into the Service Water System if there is a breach in RSHX integrity. Operation of these monitors is not required for the Recirculation Spray System or the Service Water System to accomplish their safety-related functional requirements. The RSHXs will mitigate the consequences of a LOCA in the same manner as before the change. Post-accident radiation monitors will be operated in the same manner as before the change and will be available for monitoring and assessment purposes. The consequences of previously evaluated accidents are, therefore, not increased by the proposed changes.

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

The proposed changes do not involve any physical modifications to the plant.

The RSHX service water outlet radiation monitors provide indication only. This output is displayed on the individual ratemeters and recorded on the radiation monitoring panel recorders in the Main Control Room. The ratemeter output is Page 5 of 6

also provided to the Emergency Response Facility computer. These radiation monitors do not provide a protection or control function. Reinstating the surveillance requirements for the accident monitoring instruments is administrative in nature. New failure modes or accident precursors are not introduced by the changes. Therefore, a new or different type of accident is not made possible.

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

The proposed changes do not affect any safety limits or limiting safety system settings. System operating parameters are unaffected. Operation of the RSHX service water outlet radiation monitors is not required to directly support the safety-related functional requirements of the Recirculation Spray System or the Service Water System. Since the function of the RSHX service water outlet radiation monitors is not required to satisfy the safety function of the Recirculation Spray System or the Service Water System, the operability of these monitors is not required for recirculation spray heat exchanger operability.

The RSHX service water outlet radiation monitors and the post-accident radiation monitors will be available for their monitoring functions in the same manner as before this change. Since the availability of equipment required to mitigate or assess the consequences of an accident is not reduced, safety margins are not decreased.

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