ML18065B169
| ML18065B169 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 02/23/1998 |
| From: | Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-95-07, GL-95-7, NUDOCS 9803040016 | |
| Download: ML18065B169 (15) | |
Text
consumers Energy
.r A CMS Energy Company Tlloma* t:. Bordhw Manager Licensing February 23, 1998 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT SUPPLEMENTAL INFORMATION - GENERIC LETTER 95-07, "PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES" This letter provides the supplemental information requested by the NRC to support the Palisades Safety Evaluation Report for NRC Generic Letter (GL) 95-07, "Pressure*
Locking and Thermal Binding of Power-Operated Gate Valves."
Two attachments provide the necessary information. Attachment 1 is a table which summarizes the safety function and the pressure locking and thermal binding susceptibility bases for each of the valves covered in the 180-day response to GL 95-07, dated February 13, 1996. The table also provides the corrective actions that have been or will be taken to address the pressure locking or thermal binding concerns. This table lists valves in the same order as presented to the NRC in the 180-day submittal.
Attachment 2 addresses power-operated gate valves that were susceptible to pressure locking and for which analytical models were used to determine the unseating forces.
This attachment provides the necessary information to quantify the margins available to overcome pressure_locking -~-- _ ~ I/
( . .* 9803040016 900223 ~.
L PDR P
ADOCK 05000255
-- - --- -- - -- -PDR :'. *
- J 1111111111111111111111111111111111111111 i Palisades Nuclear Plant
- 27780 Blue Star Memorial Highway
- CovtJi/, Ml 49043
- Tel: 616 764 2913
- Fax: 616 764 2490
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SUMMARY
OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.
~~
Thomas C. Berdine Manager, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades 2 Attachments
CONSUMERS ENERGY COMPANY To the best of my knowledge, the contents of this supplemental information supporting GL 95-07 response, are truthful and complete.
~~~ Thomas C. Sardine Manager, Licensing Sworn and subscribed to before me this cJ 3-' day of ~ 1998.
t
~'VY\-~~
Alora M. Davis, Notary Public Berrien County, Michigan (Acting in V~n Buren County, Michigan)
My commission expires August 26, 1999
ATTACHMENT 1 CONSUMERSENERGYCOMPANY PALISADES PLANT DOCKET 50-255 SUPPLEMENTAL INFORMATION - GENERIC LETTER 95-07 "PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES" TABLE-VALVE LIST CONTAINING SAFETY FUNCTION AND PLTB SUSCEPTIBILITY 7 Pages
ATTACHMENT 1 TABLE- VALVE LIST CONTAINING SAFETY FUNCTION AND PL TB SUSCEPTIBILITY Tag No. Descr!ption Susceptible Pressure Locking Thermal Binding to PL or TB J ustifi ca ti on/Ac ti on Justification/Action CV-0521 Alternate Steam Supply to AFW N/A Valve was removed from the plant in Valve was removed from the plant in Pump P-8B 1996 as part of modification FC-966. 1996 as part of modification FC-966.
M0-1042A PORV Block Valve PL& TB Drilled hole in upstream disc.
Completed 12/96 Converting from torque seating to limit seating in 98 REFOUT. e M0-1043A PORV Block Valve PL& TB Drilled hole in upstream disc. Converting from torque seating to limit
, Completed 12/96 seating in 98 REFOUT.
CV-3055 Shutdown Cooling Inlet to N/A Excluded from scope of NRC GL 95- Excluded from scope of NRC GL 95-Shutdown Cooling Heat 07 based on Palisades being a Hot 07 based on Palisades being a Hot Exchanger Shutdown Plant. Shutdown Plant.
CV-3070 HPSI $ub Cooling Valve PL& TB Bonnet vent path to upstream side of Valve lff of 32° Fis below.the valve will be installed prior to threshold for thermal binding of conclusion of 98REFOUT. double disc gate valves.
CV-3071 HPSI Sub Cooling Valve PL& TB Bonnet vent path to upstream side of Valve 6.T of 32° F is below the valve will be installed prior to threshold for thermal binding of conclusion of 98REFOUT. double disc gate valves.
CV-3027 SIRW Tank Recirculation N/A Valve is normally open and only has Valve is normally open and only has to close to perform its safety function. to close to perform its safety function.
It does not have to reopen. It does not have to reopen.
CV-3031 SIRW Tank Outlet N/A Valve is normally open and only has Valve is normally open and only has to close to perform its safety function.- to close to perform its safety function.
It does not have to reopen. It does not have to reopen.
CV-3056 SIRW Tank Recirculation N/A Valve is normally open and only has Valve is normally open and only has to close to perform its safety function. to close to perform its safety function.
It does not have to reopen. It does not have to reopen.
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ATTACHMENT 1 TABLE- VAL VE LIST CONTAINING SAFETY FUNCTION AND PL TB SUSCEPTIBILITY Tag No. Description Susceptible Pressure Locking Thermal Binding I
to PL or TB Justification/Action Justification/Action CV-3057 SIRW Tank Outlet N/A Valve is normally open and only has Valve is normally open and only has Jo close to perform its safety function. to close to perform its safety function.
It does not have to reopen. It does not have to reopen.
CV-0704 Slowdown Tank Discharge to Condensate Discharge N/A Valve has no active safety function to reposition.
Valve has no active safety function to reposition.
e CV-0733 Hotwell 12" Makeup Valve N/A Valve has no active safety function to Valve has no active safety function to reposition. reposition.
M0-0501 MSIV Bypass Valve N/A Valve has no ~ctive safety function to Valve has no active safety function to
' open. open.
M0-0510 MSIV'Bypass Valve N/A Valve has rio active safety function to Valve has no active safety function to open. open.
CV-3212 Shutdown Cooling Hx Inlet N/A Valve is normally open and has no Valve is normally open and has no Valve active safety function to open. active safety function to open.
CV~3213 Shutdown Cooling Hx Outlet N/A Valve is normally open and has no Valve is normally open and has no Valve active safety function to open. active safety function to open.
CV-3223 Shutdown Cooling Hx Inlet N/A Valve is normally open and has no Valve is normally open and has no Valve active safety function to open. active safety function to open.
CV-3224 Shutdown Cooling Hx Outlet N/A Valve is normally open and has no Valve is normally open and has no Valve* active safety function to open. active safety function to open.
M0-0798 Aux Feedwater Isolation Valve N/A SC 95-041 disconnected power to this SC 95-041 disconnected power to this valve. Valve retired in,place and valve. Valve retired in place and locked open. locked open.
ATTACHMENT 1 TABLE- VALVE LIST CONTAINING SAFETY FUNCTION AND PL TB SUSCEPTIBILITY Tag No. Description Susceptible Pressure Locking Thermal Binding to PL or TB Justification/Action Justification/Action M0-3041 Safety Injection Tank T-82A N/A Valve is normally open and has no Valve is normally open and has no Outlet Isolation active safety function to reopen if active safety function to reopen if closed. closed.
M0-3045 Safety Injection Tank T-828 N/A Valve is normally open and*has no Valve is normally open and has no Outlet Isolation active safety function to reopen if active safety function to reopen if closed. closed.
M0-3049 Safety Injection Tank T-82C N/A Valve is normally open and has no Valve is normally open and has no Outlet Isolation active safety function to reopen if active safety function to reopen if I
closed. closed.
M0-3052 Safety Injection Tank T-820 N/A Valve is normally open and has no Valve is normally open and has no Outlet Isolation active safety function to reopen if active safety function to reopen if closed. closed.
CV-3036 HPSI Pump P-66A to HPSI N/A Valve is normally open and has no Valve is normally open and has no Train 2 Isolation active safety function to open. active safety function to open.
CV-3037 HPSI Pump P-66A to HPSI NIA Valve is normally closed and has no Valve is normally closed and has no Train 1 Isolation active safety function to.open. active safety function to open.
CV-3059 HPSI Pump P-668 to HPSI N/A Valve is normally open and has no Valve is normally open and has no Train 1 Isolation. active safety function to open. active safety function to open.
M0-0743 Aux Feedwater Isolation Valve N/A SC 95-041 disconnected power to this SC 95-041 disconnected power to this valve. Valve retired in place and valve. Valve retired in place and locked open. locked open.
M0-0748 Aux Feedwater Isolation Valve N/A SC 95-041 disconnected power to this SC 95-041 disconnected power to this valve. Valve retired in place and valve. Valve retired in place and locked open. locked open.
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ATTACHMENT 1 TABLE- VALVE LIST CONTAINING SAFETY FUNCTION AND PL TB SUSCEPTIBILITY Tag No. Description Susceptible Pressure Locking Thermal Binding
- to PL or TB Justification/Action Justification/Action M0-0753 Aux Feedwater Isolation Valve N/A SC 95-041 disconnected power to this SC 95-041 disconnected power to this valve. Valve retired in place and valve. Valve retired in place and locked open. locked open.
M0-0754 Aux Feedwater Isolation Valve N/A SC 95-041 disconnected power to this SC 95-041 disconnected power to this valve. Valve retired in place and valve. Valve retired in place and locked open. locked open.
M0-0755 Aux Fe'edwater Isolation Valve N/A - SC 95-041 disc!onnected power to this SC 95-041 disconnected power to this valve. Valve retired in place and. valve. Valve retired in place and locked open. locked open.
M0-0759 Aux Feedwater Isolation Valve N/A SC 95-041 disconnected power to this SC 95-041 disconnected power to this valve. Valve retired in place and valve. Valve retired in place and locked open. locked open.
M0-0760 Aux Feedwater Isolation Valve N/A SC 95-041 disconnected power to this SC 95-041 disconnected power to this valve. Valve retired in place and valve. Valve *retired in place and locked open. locked open.
M0-3080 HPSI Hot Leg Injection Mode N/A Valve is normally open and has no Valve is normally open and has no Select active safety function to reopen after it active safety function'to reopen after it is closed. is closed.
M0-3081 HPSI Hot Leg Injection Mode NIA Valve is normally open and has no Valve is normally open and has no Select active safety function to reopen after it active safety function to reopen after it is closed. is closed.
M0-3189 LPSI Pump P-678 Inlet from N/A Valve is normally open and has no Valve is normally open and has no SIRWTank active safety function to open. active safety function to open.
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ATTACHMENT 1 TABLE-VALVE LIST CONTAINING SAFETY FUNCTION AND PLTB SUSCEPTIBILITY Tag No. Description Susceptible Pressure Locking Thermal Binding to PL or TB Justification/Action J ustifi ca ti on/Ac ti on M0-3198 LPSI Pump P-67 A Inlet from N/A Valve is normally open and has no Valve is normally open and has no SIRWTank active safety function to open. active safety function to open.
CV-0939 MZ-11 Shield Cooling Surge N/A This valve is excluded from further GL This valve is excluded from further GL Tank 95-07 consideration because it is a 95-07 consideration because it is a globe valve. See. Note 1 globe valve. See Note 1 M0-2087 Volume Control Tank Outlet N/A Valve is normally open and does not Valve is normally open and does not have an active safety function to have an active safety function to reopen after it closes. reopen after it closes.
CV-0437A Iodine Removal Tank Outlet N/A The valve was retired in place as part The valve was retired in place as part of FC 949. It currently has no safety of FC 949. It currently has ho safety
- function. function.
CV-04378 Iodine Removal Tank Outlet N/A The valve was retired in place as part The valve was retired in place as part of FC 949 .. it currently has no safety of FC 949. It currently has no safety function. function.
CV-0438A Iodine Removal Tank Outlet NIA The valve was retired in place as part The valve was retired in place as part of FC 949. It currently has no safety of FC 949. It currently has no safety function. function.
CV-04388 Iodine Removal Tank Outlet N/A The valve was retired in place as part The valve was retired in place as part of FC 949. It currently has no safety of FC 949. It currently has no safety function. function.
M0-2160 SIRW Tank to CVCS Isolation PL&T8 Valve has 81% margin based on Valve lff of 45° Fis below.the COMED Anplysis Method. See threshold for thermal binding of flex Attachment 2 for Inputs. wedge gate valves. There is no heat trace on this eves valve.
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ATTACHMENT 1 TABLE-VALVE LIST CONTAINING SAFETY FUNCTION AND PLTB SUSCEPTIBILITY Tag No. Description Susceptible Pressure Locking Thermal Binding to PL or TB Justification/Action J ustifi ca ti on/Action M0-2169 Boric Acid Gravity Feed PL & TB Valve has 4% margin .based on Valve .6T of 25° Fis below the lsolatiori COMED Analysis Method. See threshold for thermal binding of flex I
Attachment 2 for Inputs. wedge gate valves. The valve is heat traced and maintains a temperature of 165 ° F +/-5 °. Low alarm set point is 145° F.
M0-2170 Boric Acid Gravity Feed PL'& TB Valve has 21 % margin based on Valve .6T of 25° F is below the Isolation COMED Analysis Method. See threshold for thermal binding of flex Attachment 2 for Inputs. wedge gate valves. The valve is heat traced and maintains a temperature of 165° F +/-5°. Low alarm set point is 145° F.
M0-2140 Boric Acid Gravity Feed PL&TB Valve has 31% margin based.on Valve .6T of 25° Fis below the Isolation COMED Analysis Method. See threshold for thermal binding of flex Attachment 2 for Inputs. wedge gate valves. The valve is heat traced and maintains a temperature of 165° F +/-5°. Low alarm set point is 145° F.
CV-3018 HPSI T;rain Cross Connect N/A Valve is normally closed and has no Valve is normally closed and has no Isolation active safety function to open. active safety function to open.
M0-3190 LPSI Pump P-678 Shutdown N/A Excluded from scope of NRC GL 95- Excluded from scope of NRC GL 95-Cooling Inlet Isolation 07 based on Palisades being a Hot 07 based on Palisades being a Hot Shutdown Plant. Shutdown Plant.
M0-3199 LPSI Pump P-67 A Shutdown N/A Excluded from scope of NRC GL 95- Excluded from scope of NRC GL 95-Cooling Inlet Isolation 07 based on Palisades being a Hot 07 based on Palisades being a Hot Shutdown Plant. Shutdown Plant.
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ATTACHMENT 1 TABLE~ VALVE LIST CONTAINING SAFETY FUNCTION AND PL TB SUSCEPTIBILITY Tag No. Description Susceptible Pressure Locking Thermal Binding to PL or TB Justification/Action Justification/Action M0-3015 PCS to Shutdown Cooling N/A Excluded from scope of NRC GL 95- Excluded from scope of NRC GL 95-Isolation 07 based on Palisades being a Hot 07 based on Palisades being a Hot Shutdown Plant. Shutdown Plant.
M0-3016 PCS to Shutdown Cooling N/A Excluded from scope of NRC GL 95- Excluded from scope of NRC GL 95-Isolation 07 based on Palisades being a Hot 07 based on Palisades being a Hot
- Shutdown Plant. Shutdown Plant.
CV-3029 Containment Sump Isolation N/A Valve does have an active safety The. Containment Sump Valves are function to open. However, the valve only opened for surveillance testing disc is a solid wedge design which is during cold shutdown and then not susceptible to an occurrence of reclosed. The valves are not closed pressure IOc_king. hot. Additionally, the valves are insulated by a column of water between the valves and the Containment Sump so they will not experience large thermal transients.
CV-3030 Contai~ment Sump Isolation N/A Valve does have an active safety The Containment Sump Valves are function to open. However, the valve only opened for surveillance testing disc is a solid wedge design which is during cold shutdown and then not susceptible to an occurrence of . reclosed. The valves are not closed pressure locking. hot. Additionally, the valves are insulated by a c_olumn of water between the valves and the Containment Sump so they will not experience large thermal transients.
Note 1: During implementation of the Palisades AOV Program, CV-0939, Shield Cooling Surge Tank Inlet Valve, was verified as a globe valve. The Plant Equipment Data Base has been updated to reflect the proper valve type. The original submittal included this valve in the scope of safety related power operated gate valves. Additionally, the Palisades AOV Program has not found any other valves that were classified as globe valves that should have been gate valves.
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ATTACHMENT 2 CONSUMERS ENERGY COMPANY PALISADES PLANT DOCKET 50-255 SUPPLEMENTAL INFORMATION- GENERIC LETTER 95-07 "PRESSURE LOCKING AND THERMAL BINDING OFSAFETY-RELATED POWER-OPERATED GATE VALVES" INPUT AND ASSUMPTIONS TO PRESSURE LOCKING CALCULATIONS 3 Pages
ATTACHMENT 2 INPUT AND ASSUMPTIONS TO PRESSURE LOCKING CALCULATIONS The following inputs and assumptions were used in the COMED methodology calculations for determining the additional forces needed to unwedge a pressure locked valve (Reference Palisades Engineering Analysis EA-PLTB-00). These calculations form the basis for determining the available MOV margin as reported in Attachment 1. The differences between the available margin reported in this submittal and the margir(in the original 180 day submittal are as follows:
- 1. The original calculation used the Entergy Methodology and now the COMED Methodology is used. The methodology change reflects industry feedback on the validity
.of the two calculational methods.
- 2. There is an additional 20% margin added to the disc pullout forces to account for future changes in this force. The original calculations included the appropriate VOTES diagnostic accuracy assumptions, but this additional 20% is added to assure that future changes due to different torque switch trip settings do not create a need to revise the PL TB Calculations.
- 3. The original calculations used a generic 0.5 valve factor. This was revised to be consistent with the valve factor assumption used for NRC Generic Letter 89-10. The new valve factors for M0-2140, 2160, 2169 and 2170 are 0.8.
M0-2140, MO- 2160 Assumptions:
- 1. The maximum pressure in the bonnet is assumed to be the highest pressure seen from upstream and downstream sources. The upstream and downstream pressures are conservatively set equal to 0.0 psi at the time of valve opening. This represents the worst possible scenario.
- 2. An additional 20% margin (on top of diagnostic accuracy) is conservatively included for the measured pullout thrust values to provide for future variances in actual pullout values. *
- 3. The valves are 3", 150#, Velan flex wedge gate valves. Conversations with Velan revealed that Velan uses a 1500# class valve body for all pressure classes. As such, it is expected that the valve body/disc are indeed stiff and there is not a concern of the valve body stretching due to the bonnet pressure and the disc traveling further into the seat.
As such, additional pinching_of the v~lve disc due to this phenomena is not considered in the pressure locking calculations. These are forged valves and typically* the forging process results in a thicker (and therefore more stiff) material than a cast valve. The stiffness of the valve body and disc should preclude any significant pinching effect.
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ATTACHMENT 2 INPUT AND ASSUMPTIONS TO PRESSURE LOCKING CALCULATIONS Inputs:
Upstream Pressure 0 psi Modulus of Elasticity 29X10 6 psi Downstream Pressure 0 psi Disc Center to Hub Edge 0. 736 Bonnet Pressure 120 psi Disc Thickness 0.761 in.
Valve Disc Wedge 8° 50 Valve Factor 0.8 Structural Thrust Limit 22,894 lbf Hub Length 1 in.
Mean Seat Radius 1.281 in. Disc Coefficient of Friction 0.857 Stem Diameter 1.121 in. Poisson's ratio (disc) 0.27 Required Unseating Forces:
Pressure Locking Force: 441.7 lbf Piston Effect: -118.4 lbf Reverse Piston Effect: 107.8 lbf Pullout Thrust (M0-2140): 4800 lbf Pullout Thrust (M0-2160): 3000 lbf Total Required Force: Motor Gearing Capability:
M0-2140 5231.1 lbf M0-2140 6877 lbf M0-2160 3431.1 lbf M0-2160 6218 lbf Margin:
M0-2140 31.4%
M0-2160 81.2%
M0-2169, M0-2170 Assumptions:
- 1. The maximum pressure in the bonnet is assumed to be the highest pressure seen from upstream and downstream sources. The upstream and downstream pressures are conservatively set equal to 0.0 psi at the time of valve opening. This represents the worst possible-scenario.
- 2. An additional 20% margin (on top of diagnostic accuracy) is conservatively included for the measured pullout thrust values to provide for future variances in actual pullout values. '
- 3. The valves are 4", 150#, Velan flex wedge gate valves. Conversations with Velan revealed that Velan uses a 1500# class valve body for all pressure classes. As such, it is expected that the valve body/disc are indeed stiff and there is not a concern of the valve body stretching due to the bonnet pressure and the disc traveling further into the seat.
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i ATTACHMENT 2 INPUT AND ASSUMPTIONS TO PRESSURE LOCKING CALCULATIONS As such, additional pinching of the valve disc due to this phenomena is not con.sidered in the pressure locking calculations. These are forged valves and typically the forging process results in a thi_cker (and therefore more stiff) material than a cast valve. The stiffness of the valve body and disc should preclude any significant pinching effect.
Inputs:
Upstream Pressure 0 psi Modulus of Elasticity 29X106 psi
- Downstream Pressure 0 psi Disc Center to Hub Edge 1.25 Bonnet Pressure 120 psi Disc Thickness 0.941 in."
Valve Disc Wedge 8° 50 Valve Factor 0.8 Structural Thrust Limit 31,566 lbf Hub Length 1 in.
Mean Seat Radius 1.859 in. Disc Coefficient of Friction 0.857 Stem Diameter 1.37 in. Poisson's ratio (disc)
- 0.27 Required Unseating Forces:
Pressure Locking Force: 698.5 lbf Piston Effect: -176.8 lbf Reverse Piston Effect: 227.1 lbf Pullout Thrust (M0-2169): 5025 lbf Pullout Thrust (M0-2170): 4570 lbf Total Required Force: Motor Gearing Capability:
M0-2169 5773.8 lbf M0-2169 6022 lbf M0-2170 5318.8 lbf M0-2170 6444 lbf
- Margin:
M0-2169 4.3%
M0-2170 21.1%
As noted earlier, the apparent low margin in M0-2169 is largely a function of the additional 20% margin that was added to the pullout forces. If the additional 20%
conservatism is-neglected,-then the actualmargin for M0-2169 is 21. 9%.
Conclusion:
All valves have adequate margin to open under the assumed pressure locking conditions.
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