ML18067A703

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Forwards Response to 970826 RAI Re Valve Relief Requests (VRR) 28,30,31 & 32,submitted 970603 & 0724.Clarification of Max Test Interval for VRRs 28 & 32 Resulted in Rev to VRRs
ML18067A703
Person / Time
Site: Palisades Entergy icon.png
Issue date: 09/29/1997
From: Bordine T
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9710080159
Download: ML18067A703 (26)
v • d • e


Text

A CMS Energy Company JIJomas c. Bordlas Manager Licensing September 29, 1997 U.S. Nuclear Regulatory Commission ATTN:-* Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION -VALVE RELIEF REQUESTS 28, 30, 31, AND 32 In two letters dated June 3, 1997, and one letter dated July 24, 1997, Consumers Energy Company submitted inservice testing program valve relief requests (VRR) 28, 30, 31, and 32. VRRs 28, 30, and 31 were revised as a result of issues documented in the NRC's safety evaluation dated August 30, 1996. VRR 32 was a new relief request.

In a letter dated August 26, 1997, the NRC transmitted a request for additional information regarding these VRRs.

Attachment 1 to this letter contains the requested information. A clarification of the maximum test interval for VRRs 28 and 32 resulted in a revision to the VRRs. The revised VRRs are contained in Attachments 2 and 3 respectively.

SUMMARY

OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.

I ,.

-1 Thomas C. Bordine Manager, Licensing -

CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Mlf1  !

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ATTACHMENT 1 CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255

'*'

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION VALVE RELIEF REQUESTS 28, 30, 31, AND 32 15 Pages

  • RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 NRC REQUESTED INFORMATION
1. General For each Valve Relief Request (28, 30, 31, and 32), address the practicability of incorporating a performance review (of data in the plant and the Nuclear Plant Reliability Data System) into the testing procedure for the valves in question so that adjustments in the inspection or testing frequency and method can be made as needed.

CONSUMERS ENERGY RESPONSE

1. Conclusion Due to the critical timing and sequencing of proceduralized test activities, the incorporation into surveillance test procedures of plant and Nuclear Plant Reliability Data System (NPRDS) valve performance data reviews to make adjustments to testing frequency or methods is not considered practicable.

Rather, Palisades, on a much broader spectrum than plant data and NPRDS, reviews industry and operating experiences applicable to valve testing per its Engineering Manual and Administrative Procedures. These procedures ensure significant events that would affect valve testing frequeneies and test methods are evaluated by appropriate plant personnel. The responsible engineer would then make any necessary revisions to test procedures.

Discussion A performance review of plant data and the NPRDS to recommend adjustments in testing frequencies and/or methods is not practicable within the scope of Palisades Technical Specification Surveillance Procedures. Technical .

Specification Surveillance Procedures provide plant personnel with step by step instructions to test plant equipment, and include test result acceptance criteria.

Often, the timing and sequencing of proceduralized test activities are critical, with testing posing a potential impact on the operational status of other plant systems.

  • Completed Technical Specification Surveillance Procedures are reviewed by the lnservice Testing (IST) valve coordinator in accordance with the requirements of Palisades Nuclear Plant Engineering Manual Procedure EM-09-02, "lnservice 1

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION

  • VALVE RELl,EF REQUESTS 28, 30, 31, AND 32 Testing of Plant Valves". A Condition Report is initiated for any valve testing failure, and is evaluated in accordance with Palisades Administrative Procedure 3.03, "Corrective Action Process." The results of Corrective Action Evaluations may include adjustments to valve testing frequencies and/or test methods.

Palisades also has procedures in place to evaluate and incorporate data from NPRDS, Industry Experience, and plant data. Palisades Engineering Manual Procedure EM-70, "System Performance Monitoring", is intended to provide indications of system performance, system operations, component maintenance, and structure conditions that could contribute to inadequate system and structure

_performance. This procedure requires System Engineers to perform industry experience reviews for systems, structures, and components assigned to them.

During the review, System Engineers determine if a Condition Report is needed to resolve potential safety issues. Any such finding is documented in a System Health Report and includes a discussion of any further evaluation and action taken.

An evaluation of a Condition Report requires a review of industry data to learn from previous similar instances or to identify causes which may not be apparent when considering information from one event. Industry data available includes the Nuclear Network, NPRDS, and the Palisades Industry Experience Data Base. In the future, Palisades will be utilizing INPO's successor to NPRDS, ttie "Equipment Performance Information Exchange (EPIX)" data _base. EPIX is the data base used for industry failure reporting.

NRC REQUESTED INFORMATION

2. Valve Relief Request 28:

. 2. 1 The basis for relief states that in order to test relief valve RV-2109, an alternate means of cooling the spent fuel pool would be required to isolate the spent fuel pool heat exchangers E-53A and E-538. Provide details of the hardship involved in using "an alternate means of cooling the Spent Fuel Pool."

2

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION

  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 CONSUMERS ENERGY RESPONSE
2. Valve Relief Request 28 2.1 Conclusion The hardships involved in using alternate means of cooling the Spent Fuel Pool include the following.
1. Risk of a loss of Shutdown Cooling through open eight inch piping.
2. Potential Primary Coolant System; and/or Spent Fuel Pool Coolant leakage.
3. Potential for transuranic contamination and personnel exposure.
4. Increased radiation *exposure to plant personnel.

Discussion In order to remove RV-2109 for testing, an alternate means of cooling th_e

~sp-enffm~1-p-o-01-must_b_e-establishe*d-.-Aligning-the-Shutdown-eooling-------

System (SOC) to the Spent Fuel Pool (SFP) Cooling System is an approved alternate means of cooling the SFP. The alignment of SOC to

  • the SFP is controlled by Palisades Nuclear Plant System Operating Procedure SOP-27, "Fuel Pool System", and can only be accomplished under two plant conditions:
1. With the Reactor Cavity Flooded.
a. Primary Coolant at zero pressure.
b. Reador Cavity and SFP flooded to equal level.
c. South tilt pit gate removed.
d. Transfer tube open.
e. SOC in service per Palisades System Operating Procedure SOP-3, "Safety-Injection and-Shutdown Cooling System."
2. With the full core removed from the Reactor Vessel and stored in the SFP.

3

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION

  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32
a. Core off-load complete.
b. SFP isolated from the Reactor Cavity
c. SFP monitoring requirements of Technical Specification 3.8.5 are met.
d. SOC System secured per System Operating Procedure SOP-3, "Safety Injection and Shutdown Cooling System."
e. Pre-job briefings completed for all operators involved in this evolution.

Both plant conditions require two eight inch swing elbows that cross-tie the Fuel Pool and Shutdown Cooling Systems to be placed in position.

One of the swing elbows is located in the Spent Fuel Pool Heat Exchanger Room, and the other is located in the West Engineering Safeguards Room. To swing each elbow, Shutdown Cooling and SFP Cooling are isolated from the piping by manual isolation valves. Failure of a SOC manual isolation valve during elbow positioning would cause

.. Primary Coolant to leak into the West Engineering Safeguards Room or the Spent Fuel Pool Heat Exchanger Room, and a potential loss ofSDC.

Failure of a SFP manual isolation valve would cause SFP coolant to leak into the West Engineering Safeguards Room or the Spent Fuel Pool Heat Exchanger Room. Leakage of either Primary Coolant, or SFP Coolant

c~o-ulac"'--amre-p-ers-on-n-e1-exp-o-sure-to-transuranic-contamination-due-to-the failed fuel rod in 1993. Swinging the West Engineering Safeguards cross-tie elbows places personnel in a 14 mre.m/hr to 25 mrem/hr field.

Swinging the cross-tie elbow in the SOC Heat Exchanger Room places personnel in a 10 mrem/hr to 30 mrem/hr field and near a 600 mrem/hr hot spot.

NRC REQUESTED INFORMATION

2. Valve Relief Request 28:

2.2 Address the practicability of testing and repairing, as necessary, relief valves RV-0402, RV-0403, RV-0954, RV-0955, and RV-2109 prior to entering potential overpressure conditions after the applicable heat -

exchanger is isolated.

4

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION

  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 CONSUMERS ENERGY RESPONSE
2. Valve Relief Request 28 2.2 Conclusion It is not practicable to test and repair RV-0402, RV-0403, RV-0954, RV-0955 or RV-2109 prior to entering a potential overpressure condition.

This is because it is the process of isolating the heat exchangers that causes the overpressure condition, and the relief valves can only be removed for testing after the heat exchangers are isolated and drained.

Discussion RV-0402, and RV-0403 are the Shutdown Cooling Heat Exchangers tube side thermal relief valves. They are designed to protect the Shutdown Cooling Heat Exchangers from overpressure due to thermal expansion of water when the exchangers are isolated from the Primary Coolant System (PCS). RV-0954 and RV-0955 are the Shutdown Cooling Heat Exchangers shell side thermal relief valves. They are designed to protect the Shutdown Cooling Heat Exchangers from overpressure when the exchangers are isolated from the Component Cooling Water (CCW)

System. RV-0402, RV-0403, RV-0954, and RV-0955 are located within the boundaries of the heat exchangers' isolation valves. It is the process of isolating a heat exchanger that places it in a potential overpressure condition due to thermal expansion of water. After the Shutdown Cooling Heat Exchangers are isolated and vented, then the potential overpressure condition is eliminated. However, it is only after the Shutdown Cooling Heat Exchangers are isolated, vented, and drained that the relief valves can be removed and tested.

RV-2109 is the Spent Fuel Pool Heat Exchanger shell side thermal relief valve. It is designed to protect the Spent Fuel Pool Heat Exchanger from overpressure when the exchanger is isolated from the Component Cooling Water (CCW) System. RV-2109 is located within the boundaries of the heat exchangers' isolation valves. It is the process of isolating the heat exchanger that places it in a potential overpressure condition due to thermal expansion of water. After the Spent Fuel Pool Heat Exchanger is isolated and vented, then the potential overpressure condition is eliminated. However, it is only after the Spent Fuel Pool Heat Exchanger 5

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION

  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 is isolated, vented, and drained that RV-2109 can be removed and tested.
  • NRC REQUESTED INFORMATION
2. Valve Relief Request 28:
2. 3 Specify the maximum interval for setpoint testing.

CONSUMERS ENERGY RESPONSE

2. Valve Relief Request 28 2.3 RV-0402, RV-0403, RV-'0954, RV-0955, and RV-2109 will be removed and tested a least once every ten years. Valve Relief Request 28 has been revised to include this information and is contained in Attachment 2.

NRC REQUESTED INFORMATION

3. Valve Relief Requests 30 and 31:

The proposed alternative to relax the testing frequency for relief valves RV-0401, RV-3162, and RV-3164 could increase the likelihood and the extent of setpoint drift. A stuck open residual heat removal system relief valve has occurred following a setpoint drift to that below system pressure at some plants in the past. An emergency procedure should be in place to mitigate the consequence of such a failure. When the shutdown codling system is in service, the consequences of a stuck open relief valve (RV-0401, RV-3162, or RV-3164) could include a Joss of shutdown cooling, requiring an alternative source of heat removal, or possibly a loss-of-coolant accident. For each valve in question, please provide details of the consequences of such a failure during shutdown cooling, including descriptions of the emergency procedures in place to respond to the failure.

6

  • RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 CONSUMERS ENERGY RESPONSE
3. Valve Relief Requests 30 and 31:

Request for Additional Information Item No. 3 suggests four questions in its request for information regarding the potential relief valve failures:

1.
  • What is the likelihood of RV-0401, RV-3162, or RV-3164 opening with Shutdown Cooling in service due to setpoint drift?
2. Is there an emergency procedure in place to mitigate the consequences of a Shutdown Cooling System relief valve opening due to setpoint drift with Shutdown Cooling in service?
3. When Shutdown Cooling is in service do the consequences of a stuck open Shutdown Cooling System relief valve include a loss-of-coolant accident?
4. For RV-0401, RV-3162, and RV-3164 what are the details of the

. consequences of a failure due to setpoint drift with Shutdown Cooling in service, including emergency procedure response?

The following paragraphs will address each of the above questions.

Question 1 What is the likelihood of RV-0401,RV-3162, or RV-3164 opening with Shutdown Cooling in service due to setpoint drift?

7

  • RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 Response 1 Conclusion The likelihood of RV-0401, RV-3162, or RV-3164 opening with Shutdown Cooling in Service due to setpoint drift is low during initial alignment .of SOC to the PCS, and becomes extremely low as PCS pressure, temperature, and inventory are reduced.

Discussion The greatest probability for the relief valves actuating due to setpoint drift is when SOC is initially aligned to the Primary Cooling System (PCS).

During this plant operating condition, PCS applied system pressure to SOC is procedurally allowed to be as high as 270 psia (255.3 psig.).

RV-0401 It is highly unlikely that the setpoint of RV-0401 would drift from 2485 psig

. to 273.3 psig, which is the calculated SDC system pressure at RV-0401 for the abo\(e described operating condition.

RV-3162 A historical review of available data for setpoint testing of RV-3162 over a 71 month period shows the setpoint for this valve remained within +/-3%

for the entire period. Therefore, the probability of RV-3162 drifting low from a setpoint of 500 psig to the calculated SOC system pressure at the relief valve of 404.0 psig is low. For the setpoint of RV-3162 to drift to

  • .404.0 psig requires a 19.2% change.

RV-3164 A historical review of available data for RV-3164 shows the setpoint of this valve drifted from 300 psig to 285 psig over a 71 month period (5%

change). For RV-3164 to actuate with soe in service as describe In the - **

above paragraph, its setpoint would have to drift to a calculated pressure of 271.8. This would require a setpoint drift of 9.4% and is considered a low probability.

8

  • RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 Other Shutdown Cooling System Conditions
  • After initial alignment of the PCS to SOC, PCS temperature and pressure drop significantly below 270 psia and 300°F, and the likelihood of a relief valve lifting due to setpoint drift is further reduced. When the PCS is at.

reduced inventory, system pressures at the relief valves are:

IRV-0401 < 5 psig IRV-3162 < 190 psig IRV-3164 < 3 psig I At reduced PCS inventory the probability of a SOC relief valve lifting is extremely low for the following reasons:

1. For the plant to get to reduced PCS inventory conditions, the SOC relief valves must have remained-seated during higher system operating pressures, such as system pressures experienced when SOC is initially aligned to the PCS.
2.
  • It is overly conservative to postulate a setpoint drift of greater than 60% of normal setpoint.

Question 2 Is there an emergency procedure in place to mitigate the consequences of a Shutdown Cooling System relief valve opening due to setpoint drift with Shutdown Cooling in service?

9

  • RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 Response 2 Conclusion An emergency procedure is in place to mitigate the consequences of a Shutdown Cooling System relief valve opening due to setpoint drift with Shutdown Cooling in service. This is a low probability event, and the risk for this scenario is adequately addressed by the actions of Palisades Nuclear Plant Off Normal Procedure ONP-17, "Loss of Shutdown Cooling."

Discussion Palisades Nuclear Plant Off Normal Procedure ONP-17, "Loss of Shutdown Cooling", specifically addresses loss of Primary Coolant inventory in the unlikely event .of RV-0401, RV-3162, or RV-3164 opening with S~utdown Cooling in service.

ONP-17 directs Operators to do the following:

1. If the Primary System Drain Tank (PSDT) level is rising, then verify Shutdown Cooling Relief Valve RV-0401 has not lifted.
2. If the Quench Tank level is rising, then:
a. Verify Shutdown Cooling Relief Valve RV-3164 has not

. lifted.

b. 'If RV-3164 is lifting, then attempt to reseat relief valve.
c. Verify Low Pressure Safety Injection Relief Valve RV-3162 has not lifted.
d. If RV-3162 is lifting, then attempt to reseat relief valve.

Assuming in any o,f the above cases the relief valve lift is due to excessive setpoint drift, simple gagging would successfully stop the loss of PCS inventory. However, if diversion is not stopped, ONP-17 directs alternate PCS heat removal by using the Containment Spray Pumps, Spent Fuel Pool Cooling, or Steam Generators.

10

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION

  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 Question 3 When Shutdown Cooling is in service do the consequences of a stuck open Shutdown Cooling system relief valve include a loss-of-coolant accident?

Response 3 Conclusion When Shutdown Cooling is in service, the greatest potential for a stuck open Shutdown Cooling system relief valve is when SOC is initially aligned to the PCS. In this plant condition, the consequences of a stuck .

open Shutdown Cooling system relief valve do not include loss::-of-cooling-accident. At other SOC operating conditions the potential of a stuck open SOC relief valve is significantly lower. However, if a SOC relief valve did lift and stick open, PCS make up from' the Safety Injection and Refueling Water (SIRW) Tank would allow adequate time to implement Off Normal Operating Procedures and correct the problem as previously described.

Disc*ussion The greatest probability of relief valves RV-0401, RV-3162, or RV-3164 actuating and sticking open due to Shutdown Cooling (SOC) System pressure occurs when SOC is initially aligned to the Primary Cooling

  • System (PCS). During this plant operating condition, PCS applied.

system pressure to SOC is procedurally allowed to be as high as 270 psia (255.3 psig). Assuming the relief valve(s) lift due to setpoint drift, premature actuation will result in a PCS loss-of-coolant until the PCS can be isolated from SOC and realigned to the Steam Generators per procedure ONP-17.

After initial alignment of the PCS to SOC, PCS temperature and pressure drop significantly below 270 psia and 300°F, and the likelihood of a relief valve lifting due to setpoint drift is further reduced. Should the unlikely event of a SOC system relief valve lifting i;ind sticking open occur at these plant conditions, a loss-of-coolant accident would result. Assuming simultaneous full flow actuation of all three relief valves, make up water would be available from the SIRW Tank for approximately 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />. Also, 11

. RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION

  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 ONP-17 effectively deals with a loss of Primary Coolant inventory conditions, by directing operators to determine the cause of the loss of Primary Coolant, and reseat the stuck open relief valve as stated in the response to Question 2 above.

Question 4 For RV-0401, RV-3162, and RV-3164 what are the details of the consequences of a failure due to setpoint drift with Shutdown Cooling in service, including emergency procedure response?

Response 4 Conclusion Recovery from a failure of RV-0401, RV-3162, and RV-3164 is detailed in Palisades Nuclear Plant Off Normal Procedure ONP-17, "Loss of Shutdown Cooling." In each scenario, the eyent ends by either reseating or gagging the affected relief valve.

Discussion *.

RV-0401 RV-0401 is a Teledyne F~rris Engineering 2741 PKD/S4 safety relief valve with a 0.11 O Sq. In. orifice. It is located on the SOC suction line to

  • the Low Pressure Safety Injection (LPSI) 'pumps between valves M0-3015 and M0-3016 at approximately the 609 foot elevation in containment. RV-0401 is installed in the SOC System to protect the section of piping between M0-3015 and M0-3016 from overpressure due to thermal expansion of water with M0-3015 and M0-3016 closed. Its setpoint is set at 2485 psig to accommodate slight seat leakage from M0-3015 with the PCS at normal operating pressure. RV-0401 discharges to the Primary System Drain Tank (PSDT) T-74.

It is highly unlikely that the setpoint of RV-0401 would drift from 2485 psig down to 273.3 psig. However, should RV-0401 setpoint drift to 273.3 psig, and the SOC system experience an upset of 10% above 273.3 psig, then based solely on orifice size and not considering restrictions in the relief valve discharge piping, a stuck open RV-0401 could divert 30 gpm 12

  • RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 of water from the Low Pressure Safety Injection (LPSI) Pumps suction piping to the PSDT. This condition would result in entering Palisades Nuclear Plant Off Normal Procedure ONP-17, "Loss of Shutdown Cooling." This procedure directs operators to determine if the Primary System Drain Tank (PSDT) level is rising. If the PSDT level is rising, then it is determined if SOC relief valve RV-0401 has lifted. Once it has been determined RV-0401 has lifted, simple gagging of the relief valve would end the event (see response to Question 2 above).

RV-3162 RV-3162 is a Teledyne Farris Engineering 26FB12-141 safety relief valve with a size "F" nozzle. It provides overpressure protection to the LPSI pumps discharge header from small amounts of PCS leakage. RV-3162 discharges to the containment sump through the containment floor drain system, and is set at 500 psig.

Although the as found setpoint of RV-3162 has always been within

_tolerance, the question postulates a setpoint drift to 404.0 psig. If the setpoint of RV-3162 drifted to 404.0 psig, and the LPSI Header experienced an upset of 10% above 404.0 psig, then based solely on orifice size and not considering restrictions in the relie.f valve discharge piping, a stuck open RV-3162 could divert 101 gpm of water from the LPSI Header to the Containment Floor Drain. This condition would result in entering Palisades Nuclear Plant Off Normal Procedure ONP-17, "Loss of Shutdown Cooling."* This procedure directs operators to determine if SOC relief valve RV-3162 has lifted. Once it has been determined RV-3162 has lifted, operators are directed to attempt to reseat the valve.

If this fails, simple gagging of RV-3162 would end the event (see response to Question 2 above).

RV-3164 RV-3164 is a Teledyne Farris Engineering 26GB12-141 safety relief valve with a size "G" nozzle. It provides overpressure protection to. the SOC suction line during plant heatup. RV-3164 discharges to the Primary System Drain Tank (PSDT), and is set at 300 psig.

Plant history shows RV-3164 has drifted over a 71 month period to 285 psig. Therefore, a setpoint drift to 271.8 psig for RV-3164 can be 13

  • RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 conservatively postulated. If the setpoint of RV-3164 drifted to 271.8 psig, and the SOC suction piping experienced an upset of 10% above 271.8 psig, a stuck open RV-3164 could divert 135 gpm of Primary Coolant from SOC suction piping to the PSDT. This is based solely on orifice size and not considering restrictions in the relief valve discharge piping. This condition would result in entering Palisades Nuclear Plant Off Normal Procedure ONP-17, "Loss of Shutdown Cooling." This procedure directs operators to determine if the PSDT level is rising. If the PSDT is rising, then it is determined if SOC relief valve RV-3164 has lifted. Once it has been determined RV-3164 has lifted, operators are directed to attempt to reseat the relief valve. If reseating is unsuccessful, simple gagging of the relief valve would end the event (see response to Question 2 above).

NRG REQUESTED INFORMATION

4. Valve Relief Request 32:

For check valves CK-ES3216 and CH-ES3226 (sic), specify the maximum time for the disassembly and inspection interval and clarify the part-stroke exercise frequency of "quarterly each cold shutdown."

CONSUMERS ENERGY RESPONSE

4. Valve Relief Request 32:

Conclusion CK-ES3216 and CK-ES3226 will be disassembled and inspected at least once every ten years. Quarterly testing each Cold Shutdown occurs when the plant enters Cold Shutdown and the applicable Technical Specification surveillance test has not been performed in the last 92 days.

Discussion CK-ES3216 and CK-ES3226 will be disassembled and inspected at least once every ten years. Valve Relief Request 32 has been revised to include this information and is contained in Attachment 3.

14

  • RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
  • VALVE RELIEF REQUESTS 28, 30, 31, AND 32 Part-stroke exercising of a check valve is exercising of a check valve in the open direction with enough flow to verify disc movement off the seat, but less than full open. This test is usually performed using lower than normal system flow rates.

Quarterly testing is performed at least once every 92 days. Quarterly _testing during Cold Shutdown would be performed when the plant is in Cold Shutdown and the testing has not be performed in the last 92 days. An example of this would be if during a refueling outage Palisades Nuclear Plant Technical Specification Surveillance Procedure Q0-10, "Shutdown Cooling Air and Motor Operated Valves, Containment Spray Check Valves and Pumps Vibration, and SIRW Tank Outlet Check Valves Test", was performed and the plant returned to power operations. If the plant later entered a forced Cold Shutdown that occurred greater than 92 days after Q0-10 was performed, then Q0-10 would be .

performed again.

15

  • ATTACHMENT 2 CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION VALVE RELIEF REQUESTS 28, 30, 31, AND 32 Valve Relief Request# 28

...

. 3 Pages

RELIEF REQUEST BASIS

  • NUMBER28 SYSTEM: Engineering Safeguards M-201-2 Component Cooling M-209-2 & M-221-2 VALVES: RV-0402, RV-0403, RV-0954, RV-0955, and RV-2109 CATEGORY: c CLASS: 2 and 3 FUNCTION: RV-0402 and RV-0403 provide tube side thermal overpressure protection for the Shutdown Cooling Heat Exchangers.

RV-0954 and RV-0955 provide shell side thermal overpressure protection for the Shutdown Cooling Heat Exchangers.

RV-2109 provides shell side thermal overpressure protection for the Spent Fuel Pool Heat Exchangers.

TEST REQUIREMENT:

The scope of OM-1987, Part 1 includes pressure relief devices that are required to perform a specific function in shutting down a reactor or in mitigating the consequences of an accident.

OM-1987, Part 1, Paragraph 1.3.4 requires periodic testing of Class 2 and 3 pressure relief devices.

a. All valves of each type and manufacture shall be tested within each subsequent 10 year period.
b. A minimum of 20% of the valves shall be tested within any 48 months.

BASIS FOR RELIEF:

Relief is requested in accordance with 10CFR50.55a(a)(3) from testing RV-0402, RV-0403, RV-0954, RV-0955, and RV-2109 on the basis that the proposed alternative will provide an acceptable level of quality.

Complying with the Code is impractical. RV-0402, RV-0403, RV-0954, RV-0955, and RV-2109 are designed to protect the Shutdown Cooling Heat Exchangers and the Spent Fuel Pool Heat Exchanger from thermal expansion of water when 1

RELIEF REQUEST BASIS NUMBER28 the exchangers are isolated for maintenance or inspection. These thermal relief valves have no safety function when the heat exchangers are in service. To remove these thermal relief valves, the associated heat exchangers must be isolated. However, the Shutdown Cooling Heat Exchangers cannot be isolated during power operations, nor isolated when there is fuel in the Reactor Vessel.

To isolate the Shutdown Cooling Heat Exchangers, all fuel must be removed from the reactor vessel. To Isolate the Spent Fuel Pool Heat Exchanger, an alternate means of cooling the Spent Fuel Pool must be established.

Compliance would result in a hardship without compensating increase in safety.

RV-0402, RV-0403, RV-0954, and RV-0955 are welded in place, and are located in a high radiation area. Removal, testing and reinstallation would cause an increase in radiation exposure to plant staff. RV-0402, RV-0403, RV-0954, RV-0955, and RV-2109 do not provide overpressure protection when the associated heat exchanger is in service, nor do they serve a safety function during plant operation to ensure the reactor can be safely shutdown or to mitigate the consequences of an accident. These relief valves are only needed when the associated heat exchanger is isolated. Therefore, there is no benefit in verifying the set point for these relief valves while the heat exchangers remain in service.

ALTERNATIVE TESTING:

Each time Shutdown Cooling Heat Exchanger E-60A is removed from service and isolated for maintenance or inspection RV-0402 and RV-0954 will be tested in accordance with OM-1987, Part 1, Section 8 unless they have been tested within the last 48 months.

Each time Shutdown Cooling Heat Exchanger E-608 is removed from service and isolated for maintenance or inspection RV-0403 and RV-0955 will be tested in accordance with OM-1987, Part 1, Section 8 unless they have been tested within the last 48 months.

Each time Shutdown Cooling Heat Exchangers E-53A and E-538 are removed from service and isolated for maintenance or inspection RV-2109 will be tested in accordance with OM-1987, Part 1, Section 8 unless it has been tested within the last 48 months.

RV-0402, RV-0403, RV-0954, RV-0955, and RV-2109 will be removed and setpoint tested at least once every ten years.

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RELIEF REQUEST BASIS

  • NUMBER28 ACCEPTANCE CRITERIA:

Acceptance Criteria for the testing of RV-0402, RV-0403, RV-0954, RV-0955, and RV-2109 shall be established in accordance with Palisades Nuclear Plant Permanent Maintenance Procedure MSM-M-60, "ASME Safety/Relief Valve Testing for Valves Included in ASME Section XI Scope."

Additional actions for valves that fail "As Found" set point testing are specified per Palisades Nuclear Plant E11gineering Manual Procedure EM-09-02, "lnservice Testing of Plant Valves."

STATUS:

This relief request requires prior NRC approval in accordance with the provisions of 10CFR50.55a(a)(3).

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ATTACHMENT 3 CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION VALVE RELIEF REQUESTS 28, 30, 31, AND 32

  • Valve Relief Request# 32 4 Pages

RELIEF REQUEST BASIS NUMBER32 SYSTEM: Engineering Safeguards (Containment Spray/M203-2)

VALVES: CK-ES3216, CK-ES3226 CATEGORY: c CLASS: 2 FUNCTION:

These eight inch check valves perform an active safety function in the open position to admit containment spray flow to the spray headers. These valves open when containment spray is automatically initiated on a Containment High

  • Pressure (CHP) signal.

These valves have no safety function in the closed position. Since the containment spray system will be in operation during an accident condition requiring containment integrity, these valves are not considered to be required for containment integrity. These valves function to prevent ba_ckflow to the shutdown cooling system during system testing.

TEST REQUIREMENT:

ASME/ANSI OMa-1988, Part 10 4.3.2.2: Exercising Requirements (a) During plant operation, each check valve shall be exercised or examined in a manner which verifies obturator travel to the closed, f1.,1ll open, or partially open position required to fulfill its function.

(e) If exercising is not practical during plant operation or cold shutdowns, it may be limited to full-stroke during refueling outages.

4.3.2.4: Valve Obturator Movement (a) The necessary valve obturator movement shall be demonstrated by exercising the valve and observing that ei.ther the obturator travels to the seat on cessation or reversal of flow, or opens to the position required to fulfill its function, as specified in para.1.1, or both.

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RELIEF REQUEST BASIS NUMBER32 Observation may be by observing a direct indicator such as a position indicating device, or by other indicator(s) such as changes in system pressure, flow rate, level, temperature, seat leakage testing or other positive means.

(b) If a manual mechanical exerciser is used to move the obturator, the force or torque required to initiate movement (breakaway) shall be measured and recorded. The breakaway force shall not vary by more than 50% from the established reference value. The reference value used shall be the value obtained when the valve is known to be operating properly, and sha.11 be taken under conditions as close as practicable .to the conditions under which the

  • valve will be tested, e.g., wet vs. dry equivalent static head, etc.

(c) As an alternative to the testing in (a) or (b) above, disassembly every refueling outage to verify operability of check valves "!lay be used.

Generic Letter No. 89-04 Position 2: The NRC staff position is that valve disassembly and inspection can be used as a positive means of determining that a valve's disk will full-stroke exercise open or of verifying closure capability.

c. Where the licensee determines that it is burdensome to disassemble and inspect all the applicable valves each refueling outage, a sample disassembly and inspection plan for groups of identical valves in similar applications may be employed.

BASIS FOR RELIEF:

Relief is requested in accordance with 10CFR50.55a(a)(3) from disassembling and inspecting a sample (one) valve each refueling outage on the basis that the alternative proposed will provide an acceptable level of quality and safety.

The result of a full-stroke exercise of the containment spray check valves would be the initiation of the containment spray system and spraying down containment. The original plant design did not provide a test circuit for these 2

RELIEF REQUEST BASIS NUMBER32 valves. As a result, full stroke testing is not practical during any mode of operation. Therefore, because of this limitation, Palisades has implemented disassembly and inspection, and part stroke testing in accordance with Generic Letter 89-04. This program requires on~ valve of the group composed of CK-ES3216 and CK-ES3226 to be disassembled and inspected each refueling outage, and quarterly part stroke testing when the plant is in cold shutdown.

During periods where shutdown cooling is required, the disassembly would require a single valve isolation from the Containment Spray System using a valve with air operator closure. Loss of control air to this single valve could result in a loss of shutdown cooling or reduced shutdown cooling effectiveness.

Leakage past the valve could also present difficulties in completin*g valve inspections. Disassembly of the containment spray check valves also results in increased dose to plant staff on the order of 200mR/worker.

yalve CK-ES3216 was disassembled and inspected during the 1994 refueling outage in accordance with work order 24416316. This was the first disassembly and inspection performed since initial plant installation and testing. The inspection indicated the valve was in good condition with little or no degradation after 23 years of service.

Valve CK-ES322E? was disassembled and inspected during the 1996 refueling outage in accordance with work order 24613344. This was the first disassembly and inspection performed since initial plant installation and testing. Inspection indicated the valve was in good condition with little or no degradation after 25 years of service.

A review of industry experience for this type of valve does not indicate any adverse performance experience associated with valves in mild service similar to the containment spray header check valves. The containment spray system is composed of stainless steel piping components rated at 500 psig and 350 °F, and transports clean borated water. The spray header check valves do not see service conditions at any time other than system surveillance testing. No degradation mechanisms associated with system service or testing have been identified.

A search of Palisades specific experience indicates no corrective actions or work orders *associated with these valves.

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RELIEF REQUEST BASIS

  • NUMBER32 ALTERNATIVE TESTING:

Valves CK-ES3216 and CK-ES3226 will be part-stroke exercised quarterly each cold shutdown per Q0-10.

Palisades proposes to extend the disassembly and inspection interval for CK-ES3216 and CK-ES3226, such that, both valves will be disassembled and inspected at full core off-loads or when shutdown cooling can be isolated, provided the valves have not been disassembled and inspected in the previous 40 months.

At each disassembly, the valves will be manually exercised to verify full-stroke capability. Also, the disassembled valve will be inspected to ensure the internals are structurally sound (no loose, damaged, or corroded parts).

CK-ES3216 and CK-ES3226 will be disassembled and inspected at least once every ten years ..

ACCEPTANCE CRITERIA:

At each disassembly, the valves will be manually exercised to verify full-stroke capability. Also, the disassembled valve will be inspected to ensure the internals are structurally sound (no loose, damaged, or corroded parts).

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