ML20196L377
| ML20196L377 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 06/30/1988 |
| From: | Fay C WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| CON-NRC-88-063, CON-NRC-88-63 IEB-85-003, IEB-85-3, VPNPD-88-342, NUDOCS 8807070411 | |
| Download: ML20196L377 (13) | |
Text
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Wisconsin Electnc a com 231 W. MICHIGAN, P.O. BOX 2046. MILWAUKE E, W153201 (414)277 2345 VPNPD-88-342 NRC-88-063 June 30,1988 Document Control Desk U.S. NUCLEAR REGULATORY COMMISSION Mail Station P1-137 Washington, D.C. 20555 Gentlemen:
DOCKETS 50-266 AND 50-301-F INA' RESPONSE TO IE BULLETIN 85-03 MOTOR-0PERATE0 VALVE SWITCH SETTINGS POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 IE Bulletin no. 85-03, "Motor-0perated Valve Common Mode Failure During Plant Transients Due to Improper Switch Sattings," was issued on November 15, 1985 to inform licensees of a potential problem involving the operability of motor-operated valves as a result of improper switch settings.
The bulletin requested licensees to develop and implement a program to ensure that switch settings on certain safety-related motor-operated valves are seleci.ed, set and maintained correctly to accommodate the maximum differential pressures expected on these valves during both normal and abnormal events within the design basis.
Our submittals to you dated May 2, 1986 and May 5, 1987 provided our response to the Bulletin Action Items a and e.
The purpose of this letter is to provide our written report in response to Bulletin Action Items b, c, d, and f.
Since the issuance of the bulletin, Point Beach Nuclear Plant personnel have developed a motor-operated valve (MOV) stem thrust measurement system which accurately measures, in a direct manner, packing load, thrust at torque switch trip, over thrust, and open torque switch bypass timing.
Point Beach did not pursue the conventional method of monitoring spring pack displacement due to the inability to measure packing load, the effects of packing adjust-ment on spring pack calibration, and the intrinsic assumption that open and close drive train efficiencies are equal. Attachment 1 provides a discussion of the thrust measurement results.
The thrust required for a given MOV differential pressure can be set precisely at static conditions as calculated per Action Item b of the Bulletin or as obtained from differential pressure testing results. consists of a tabular listing of the data requested per Action Items a, b and c of IEB 85-03.
Minimum torque switch settings are based upon
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1 PDR ADO 266 Q
NRC Document Control Desk c
June 30,1988 Page 2 calculated requirements for closing or opening the valves under design differential pressure conditions.
Maximum torque switch settings are based upon the limiting thrust for the following three considerations:
1.
Valve component failure 2.
Operator component failure 3.
Motor / Actuator stall under degraded voltage conditions.
Limit switch settings are based upon the following:
1.
Position indication requirements 2.
Open torque switch bypass requirements.
Bypass requirements are determined by considering turbulent fluid flow effects through valves as unseating takes place.
3.
Limiting valve open travel.
Where 2-train limit switch assemblies are applied, a compromise between position indication and bypass requirements must be achieved.
Action Item d of the bulletin requires procedures be prepared or revised to ensure that correct switch settings are determined and maintained throughout the life of the plant.
The utility should ensure that applicable industry recommendations are considered in the preparation of these procedures.
Point Beach has developed the following Maintenance Instructions, which comply with the requirements of Action Item d:
MI 5.1.1 "Limitorque MOV Torque and Limit Switch Adjustment for Gate and Globe Valves."
MI 5.1.2 "Limitorque MOV Torque and Limit Switch Adjustment for Butterfly Valves."
MI 5.1.4 "Limitorque Model SMB-000 Disassembly, Inspection, Repair and Reassembly."
MI 5.1. 5 "Limitorque Motor Operated Valves Models SMB-0 Thru SMB-4 Disassembly and Reassembly."
MI 5.1.6 "Limitorque Model SMB-00 Disassembly, Inspection, Repair and Reassembly."
Action Item f of the bulletin requested a written report be provided at the completion of the program.
This report is to include (1) a verification of completion of the test program, (2) a summary of the findings as to valve operability prior to any adjustments as a result of the bulletin, and (3) a summary of data in accordance with Table 2 of the Bulletin, Suggested Data Summary Format.
This report is provided below:
.k' NRC Document Control-Desk June 30, 1988 Page 3.
verification of Completion of Test Program The attached table provides documentation of the initial switch settings and the valve stroke tests with the obtained Test Delta P for each of the valves.
In several cases the Test Oelta P is slightly greater than the Maximun Delta P.
This occurred because in some cases the individuals recording the pressure did not record the differential pressure but rather the full flow upstream pressure.
All valves'were tested close to the maximum differential pressure expected under simulated accident conditions requiring valve operation.
The attached table also provides the recommended torque switch settings, actual settings, calculated required thrust, and actual measured thrust.
From the table it can be seen that there are several differences between recommended torque switch settings and actual settings. -These differences are explained in the comments section accompanying the table.
Summary of Findings of Valve Operability All valves performed their design safety function in the as-found condition during full delta P testing.
Valve 1-866A would not closet however, the direction of travel for its design safety function is to open which-it did.
The motor was subsequently replaced.
Summary of Data A summary of the data is provided in the attached Valve Data Table and summary comments.
We are confident based on full DP testing and stem thrust measurements that all of the M0V's will perform their required automatic safety functions under i
design-basis conditions.
Please contact us if you have any questions regarding this information.
Very truly yours,
'/
/
/
C. W. Fay Vice President Nuclear Power i
Enclosures Copy to:
Regional Administrator, Region III NRC Senior Resident Inspector Subscribed and sworn to before ma this3ou day of b 4, 1988.
m0 Cm Notary Public, State of Wisconsin My Commission expires f-2 7 'lo.
.c Juns 30,1988 Discussion of MOV Stem Thrust Measurement Results Point Beach Nuclear Plant, Units 1 and 2 Differential pressure testing by PBNP personnel concluded that there was a discrepancy between vendor calculations and valve requirements for differential pressure operation.
Vendor calculations consider three items when determining thrust requirements.
The three factors are:
1.
Piston effect = stem cross-sectional area times differential pressure.
The piston effect factor is fairly straight forward and does not account for or contribute significantly to the discrepancy.
2.
Packing load as determined from standard tables.
Packing loads are easily measured in the field and are typically 25 to 50% of values assumed for design-basis calculations.
This is attributed to the use of newer more efficient packing materials.
On occasion, packing loads as high as 70% of Design Basis have been observed.
Only in isolated cases were packing loads found to be as high as the loads used for design basis calculations.
These isolated cases are attributed to the existence of the older packing materials in the stuffing boxes.
3.
Differential Pressure requirement as determined by disk or plug area times differential pressure times the valve coefficient of frici, ion.
By factoring out pis g effect(1) and packing load (2)
, it was concluded that the friction factors used in performing the calculations for gate valves were non-conservatively low.
The friction factors empirically determined are typically two to three times as great as the values traditionally used for the calculations.
The friction values used in performing differential pressure calculations for globe valves are considered to be conservatively high.
For example, 1-878 globe valve actual thrust requirement at maximum differential as compared to the calculated 10,800 lb.
pressure is apprnximately 5,500 lbf f
Further investigation and analysis has determined that Limitorque has made an extremely conservative assumption in sizing motor actuators.
This assumption is that the stem to stem-nut coefficient of friction is 0.2.
Field testing has determined that this valve is typically in the 0.09 to 0.12 range.
For example, an operator may have been originally sized m.d specified to operate at 10,000 lb.
For a stem to stem-nut coefficient of friction of 0.1 the operator is $ost likely operating at 15,000 lb.
If the stem to stem-nut coefficientisassumedtobe0.15,theresulti$gthrustoutputwillbe approximately 12,000 lb.
f PBNP did not have all of this data compiled when the vendor was originally tasked with verifying the valve calculations and torque switch setting evalu-ation.
A review of the vendor calculations and torque switch recommendations concluded that the only potential p)oblem area is the 1-866A and 1-866B M0V's.
If either valve is closed during an unexpected degraded voltage conditica, their motor thermal overloads may actuate.
This condition is being tracked internally through a Nonconformance Report (NCR).
A modification of motor operators for 1-866A and 1-866B is currently being evaluated.
m In conclusion, operator sizing is not considered to be a problem.
The error introduced by use of the low valve friction factors is typically offset by the following factors:
1.
Conservatively high packing load.
2.
Conservatively high stem to stem-nut coefficient of friction.
3.
Differential pressures used in the original thrust calculations are typically higher than the differential pressures attainable in practice.
The vendors have been directed to re-do the calculations and 6.orque switch recommendations based on the following inputs:
1.
Packing loads are 70% of the traditionally used values.
2.
Stem to stem-nut coefficient of friction is 0.15.
This is considered to be a conservatively high value.
3.
Friction factors to be used in performing gate valve calculations are to be doubled.
If the gate valve is used in a chromated water system, the friction factor is to be increased by 250%.
If a review of the revised calculations and recommendations yields any signifi-cant findings, a supplement to this response will be initiated.
MOTOR 4PERATED VALVE DAT_A__SU MARY RESPONSE TO IE:A 8S Q POINT BEACH NUCLEAR PLANT. UN QS.1 AND 2 JUNE 30,1988 Valve I.D.
0-4020 0-4021 0-4022 0-4023 1-2019 2-2019 1-2020 2-2020 Valve Mfr.
Powell Powell Powell Powell Powell Powell Powell Powell Valve Type Gate Gate Gate Gate Globe Globe Globe Globe
?
Valve Model 19023 WE 19023 WE 19023 WE 19023 WE 6084 WE 6084 WE 6084 WE 6084 WE Valve Size 3"
3" 3"
3" 3"
3" 3"
3" Rating 900#
900#
900#
900*
6008 600#
600#
600#
Operator Mfr.
Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Model SMB-000 SMB-OOO SMB-OOO SMB-OOO SMB-OO SMB-OO SMB-OO SMB-CO Motor RPM 1725 1725 1725 1725 1900 1900 1900 1900 Output Spd."/an 12.25 12.25 12.25 12.25 5.375 5.375 5.375 5.375 Valve Function Must Close to isolate Aux. Feedwater flow from Must open to admit steam to turbine driven Motor Driven AFWP'to unaffected unit Sta. Gen.
Aux. Feedwater Pump.
Design Delta P Open/Close(psid) 1560/15EO 1560/1560 1560/1560 1560/1560 1085/1085 1085/1085 1085/1085 1085/2085 l
Maximum Delta P Open/Close(psid) 1305/1305 1305/1305 1305/1305 1305/1305 1085/1085 1085/2085 1085/2085 1065/1085 Test Delta P Open/Close(psid) 1350/1350 1330/1330 1350/1350 1340/1340 930/930 960/960 950/950 965/965 Prior Settings
- j (Open/Close) 4.0/4.0 3.0/3.4 1.1/2.9 3.0/3.25 1.25/1.25 2.0/2.0 1.6/1.6 1.6/1.5 Final Settings (Open/Close) 4.0/4.0 3.0/3.4 3.0/3.7 3.5/3.5 1.25/1.25 2.0/2.0 1.6/1.6 1.6/1.5 Min. Setting (Open/Close 100%)1.75/1.75 1.75/3.75 1.75/1.75 1.75/1.75 1.875/1.875 1.875/1.875 1.875/1.875 1.875/1.875 Max. Setting (Open/Close 100%) 2.5/2.5 2.5/2.5 2.5/2.5 2.5/2.5 2.125/2.125 2.125/2.125 2.125/2.125 2.125/2.125 Max. Setting (Open/Close 80%)
2/2 2/2 2/2 2/2 2.125/2.125 2.125/2.125 2.125/2.125 2.125/2.125 Calc. Min / Max. Thrust (2000's LBS.)
4.9/8 4.9/8 4.9/8 4.9/8 12.2/14 12.2/14 12.2/14 12.2/14 Signature Thrust (2000's LBS.)
7.6 6.7 6.0 7.6 12.8 12.1 12.0 17.0 As Found i
Operable Yes Yes Yes Yes Yes Yes Yes Yes Test Method, I
D2scription and Justification ***
Full DP Full DP Full DP Full DP Full DP Full DP Full DP Full DP Minimum and maximum required settings at 80 and 100% of rated voltage are based on calculations Torque switch.
by a vendor.
Signature thrust obtained by Point Beach stem thrust measurement system with no differential pressure.
- Full DP indicates functional test for operability at indicated differential pressure per part b of 85-03.
- Signature thrust obtained by Point Beach stem thrust measurement system with indicated differential pressure.
1
MOTOR-OPERATED VALVE DATA
SUMMARY
RESPONSE TO IEB 85-03 POINT BEACH NUCLEAR PLANT. UNITS 1 AND 2 JUNE 30.1988 Valve I.D.
1-4006 2-4006 0-4009 O-4016 1-4000 2-4000 1-4001 2-4001 a
valve Mfr.
Powell Powell Powell Powell Powell Powell Powell Powell Valve Type Gate Gate Gate Gate Globe Globe Globe Globe Valve Model 2453 SG 2453 SG 2453 SG 2453 SG 19051 WE 19051 WE 19051 WE 19051 NE Valve Size 6"
6" 4"
4" 3"
3" 3"
3" Rating 150#
!!O#
150#
150#
900#
900#
900#
900#
Operator Mfr.
Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Modal SMB-OOO SMB-OOO SMB-OOO SMB-OOO SMB-OO SMB-OO SMB-OO SMB-OO i
Motor RPM 1725 1725 1725 1725 1900 1900 1900 1900 Output Spd.*/an 13.00 14.00 8.75 8.75 7.375 7.375 7.375 7.375 Valve Function Opens to provide service water to the suction Normally in mid position to provide 200 gpm of the Aux. Feedwater Pumps.
to each sta. gen. from Aux. Feedwater pumps.
Dealgn Delta P Open/Close(psid) 150/150 150/150 150/150 150/150 1560/1560 1560/1560 1560/1560 1560/1560 Maximum Delta P Open/Close(psid) 76/76 76/76 76/76 76/76 1340/1340 1340/1340 1340/1340 1540/1340 Tact Delta P Open/Close(psid) 79/79 78/78 75/7C 77/77 1100/1100 1075/1075 1100/1100 1075/2075 i
Prior Settings *
(Open/Close) 5.0/1.1 2.25/2.5 6.0/1.0 4.5/1.1 1.5/1.5 1.75/1.75 1.5/1.5 1.75/1.75 Final Gettings (Open/Close) 5.0/1.1 2.25/2.5 6.0/1..O 4.5/1.1 1.5/1.5 1.75/1.75 1.5/1.5 1.75/1.75 Min. Setting (Open/Close 100%) 1/1 1/1 1/1 1/1 1.625/1.625 1.625/1.625 1.625/1.625 1.625/1.625 Max. Setting (Open/Close 100%) 4/4 4/4 2.5/2.5 2.5/2.5 2.125/2.125 2.125/2.125 2.125/2.125 2.125/2.125 Max. Setting (Open/Close 80%)2.5/2.5 3/3 1.5/1.5 1.5/1.5 2.125/2.125 2.125/2.125 2.125/2.125 2.125/2.125 Calc. Min / Max Thrust (IOOO's LBS.)
1.7/8 1.7/8 1.3/8 1.3/8 10.7/14 10.7/14 10.7/14 10.7/14 Signature Thrust (2000's LBS.)
4.3 12.1 16.5 13.4 15.4 Aa Found Operable Yes Yes Yes Yes Yes Yes Yes Yes i
Teat Method, Description and Justification *** Full DP Full DP Full DP Full DP Full DP Full DP Full DP Full DP
Minimum and maximum required settings at 80 and 100% of rated voltage are based on calculations by a vendor.
Signature thrust obtained by Point Beach stem thrust measurement system with no differential pressure.
- Full DP indicates functional test for operability at indicated differential pressure per part b of 85-03.
2
MOTOR-OPERATED VALVE DATA SUpstARY RESPONSE TO IEN 85 "3 POINT PEACH NUCLEAR PLANT. UNITS 1 AND 2 JUNE 30,1Fa8 Valve I.D.
1-878A 2-878A 1-878C 2-878C 1-878B 2-878B 1-878D 2-878D Valve Mfr.
Velan Velan Velan Velan Velan Velan Velan Velan Valve Type Globe Globe Globe Globe Globe Globe Globe Globe Valve Model 137.116 137.116 137.116 137.116 137.116 137.116 137.116 137.116-Valve Size 2"
2" 2"
2" 2"
2" 2"
2" Rating 15008 1500*
1500#
1500#
1500#
15008 15008 1500#
Operator Mfr.
Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Model SMB-OO SMB-OO SMB-OO SMB-OO SMB-OO SMB-OO SMB-OO SMB-03 Motor RPM 1800 1800 1800 1800 1800 1800 1800 1800 Output Spd."/an 9.00 9.00 9.00 9.00 9.00 9.00 9.00 9.00 Valve Function To be opened at operator discretion if high Normally open.
Must remain open to allow high head core deluge is deemed beneficial.
head safety injection to RCS cold legs.
Design Delta P Open/Close(psid) 2485/2485 2485/2485 2485/2485 2485/2485 2485/2485 2485/2485 2485/2485 2485/2485 I
Maximum Delta P Open/Close(psid) 1670/1670 1670/1670 1670/1670 1670/1670 1670/1670 1670/1670 1670/1670 1670/1670 Tact Delta P Open/Close(psid) 1680/1680 1700/1700 1680/1680 1700/1700 1680/1680 1700/1700 1680/1680 1700/1700 Prior Settings *
(Open/Close) 2.2/2.2 1.75/2.2 1.5/1.25 1.75/1.75 1.5/1.5 1.5/3.8 1.5/1.5 1.5/2 O Final Settings (Open/Close) 2.2/2.2 1.75/2.2 1.5/1.25 1.75/1.75 1.5/1.5 1.25/1.25 1.25/1.25 1.5/2.3 Min. Setting (Open/Close1004)1.375/1.375 1.375/1.575 1.375/1.375 1.375/1.375 1.375/1.375 1.375/1.375 1.375/1.375 1.375/1.375 Max. Setting (Open/Close100%)1.875/1.875 1.875/1.875 1'.875/1.875 1.875/1.875 1.875/1.875 1.875/1.875 1.875/1.875 1.875/1.875 Max. Setting (Open/Close 804) 1.5/1.5 1.5/1.5 1.5/1.5 1.5/1.5 1.5/1.5 1.5/1.5 1.5/1.5 1.5/1.5 Calc. Min / Max. Thrust (1000's LBS.)
11.5/14 11.5/14 11.S/14 11.5/14 11.5/14 11.5/14 11.5/14 11.5/14 Signature Thrust (1000's LBS.)
13.5 21.5 14.2 15.2 15.4 An Found Operable Yes Yes Yes Yes Yes Yes Yes Yes Test Method, Description and Justification *** Full DP Full DP Full DP Full DP Full DP rull DP Full DP Full DP Torque switch.
Minimum and maximum required settings at 80 and 100% of rated voltage are based on calculations by a vendor.
Signature thrust obtained by Point Besch stem thrust measurement system with no differential pressure.
- Full DP indicates functional test for operability at indicated differential pressure per part b of 85-03.
- Opened as required to perform safety function. Would not close. Motor replaced.
3
4 MOTOR-OPERATED VALVE DATA FUMMARY RESPONSE TO IEB 85-03 POINT t'EACH NUCLEAR PLANT. UNITS 1 AND 2 JUNE 30.1988 Valve I.D.
1-825A 2-825A 1-825B 2-825B 1-826B 2-826B 1-826C 2-826C Vnive Mfr.
Aloyco Aloyco Aloyco Aloyco Aloyco Aloyco West.
Aloyco Valve Type Gate Gate Gate Gate Gate Gate Gate Gate Valve Model 216-VGS-SP 216-VGS-SP 216-VGS-SP 216-VGS-SP 216-VGS-SP 216-VGS-SP 5710-99 216-VGS-SP Valve Size 12" 12" 12" 12" 8"
8" 8"
8" Rating 150#
150#
150#
1508 150#
1508 300#
1508 Operator Mfr.
Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Model SMB-1 SMB-1 SMB-1 SMB-1 SMB-OO SMB-00 SMB-OO SMB-00 Motor RPM 3600 3600 3600 3600 1800 1800 1700 1800 Output Spd."/mn 60 60 60 60 52.5 52.5 51 52.5 Valve Function Opens to provide suction to the high head Opens to provide suction to the high head safety Safety Injection Pumps from the RWST.
Injection pumps from Boric Acid Tanks.
Design Delta P Open/Close(psid) 150/150 150/150 150/150 150/150 200/200 200/200 200/200 200/200 Maximum Delta P Open/Close(psi 4) 30/30 30/30 30/30 30/30 12/12 12/12 12/12 12/12 Test Delta P Open/Close(poid) 28.6/28.6 28.G/28.6 28.6/28.6 30/30 19.S/19.5 29.5/29.5 10.43/10.43 29.5/29.5 Prior Settings *
(Open/Close) 2.7/2.7 2.25/2.25 2.0/1.5 3.25/3.4 1.8/1.8 2.4/2.6 3/3 2.4/2.5 Final Settings (Open/Close) 2.7/2.7 2.25/2.25 2.0/1.5 1.8/1.8 1.8/1.8 1.J5/1.75 3/3 2.0/2.0 Min. Setting (Open/Close1004)1.25/1.25 1.25/3.25 1.25/1.25 1.25/1.25 1.25/1.25 1.25/1.25 2/2 1.25/1.25 Max. Setting (Open/Close1004) 4/4 4/4 4/4 4/4 3.25/3.25 3.25/3.25 3/3 3.25/3.25 Max. Setting (Open/Close 804)3.25/3.25 3.25/3.25 3.25/3.25 3.25/3.25 2.25/2.25 2.25/2.25 3/3 2.25/2.25 Calc. Min / Max Thrust (2000's LBS.)
2.8/12.3 2.8/12.3 2.8/12.3 2.8/12.3 1.7/9.4 1.7/9.4 4.4/13.5 1.7/9.4 Signature Thrust **
(2000's LBS.)
11.1 6.6 6.8 9.3 6.6 An Found Operable Yes Yes Yes Yes Yes Yes Yes Yes Test Method, Description and Justification ***' Full DP Full DP Full DP Full DP Full DP Full DP Full DP Full DP
Minimum and maximum required settings at 80 and 100% of rated voltage are based on calculations by a vendor.
Signature thrust obtained by Point Beach stem thrust measurement system with no differential pressure.
- Full DP indicates functional test for operability at indicated differential pressure per part b of 85-03.
4
7_____.___-_..
MOTOR-OPERATED VALVE DATA SUDetARY RESPONSE TO I'M 85-c3 POINT BEAC1 NUCLEAR PLANT. UNITS 1 AND 2 JUNE 39.1M?8
~
Valve I.D.
1-896A 2-896A 1-896B 2-8965 1-866A 2-866A 1-866B 2-866B Valve Mfr.
Aloyco Aloyco Aloyco Aloyco Darling Darling Darling Darling Valve Type Gate Gate Gate Cate Gate Gate Gate Gate Valve Model 216-VGS-SP 216'-VGS-SP 216-VGS-SP 216-VGS-SP 11986 11986 11986 11986 Valve Size 6"
6" 6"
6" 4"
4" 4"
4" Rnting 150s 150#
150#
1508 90C#
9008 900*
900#
Operator Mfr.
Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Limitorque Model SMB-OO SMB-OO SMB-OO SMB-OO SMB-DO SMB-OO SMB-OO SMB-OO Motor RPM 1800 1800 1800 1800 1800 1800 900 900 Output Spd."/an 60 60 10 10 11.4 11.4 11.4 11.4 Valve Function Normally Open.Must remain open to allow suction Normally Open.Must remain open to allow high head to the high head safety injection pumps.
safety injection to the RCS.
Design Delta P Open/Close(psid) 150/150 150/150 150/150 150/150 1745/1745 1745/1745 1745/1745 1745/1745 Maximum Delta P.
Open/Close(psid) 30/30 30/30 30/30 30/30 1670/1670 1670/1670 1670/1670 1670/1670 Toot Delta P Open/Close(psid) 31/31 28/28 31/31 28/28 1680/1680 1700/1700 3680/1680 1700/1700 Prior Settings *
(Open/Close) 2.0/1.5 1.6/1.6 2.0/2.75 2.0/2.75 1.5/1.5 1.5/1.5 2/2 1.5/1.5 Final Settings (Open/Close) 1.5/1.5 1.6/1.6 1.25/1.25 2.0/2.75 1.5/1.5 1.5/1.5 2/2 1.5/1.5 Min. Setting
~
(Open/Close1004)1.25/1.25 1.25/1.25 1.25/1.25 1.25/1.25 1/2.375 1/2.375 1/1.375 1/1.375 Max. Setting (Open/Close100%)1.75/1.75 1.75/1.75 1.75/3.75 1.75/1.75 2/2 2/2 2/2 2/2 Max. Setting (Open/Close 804)1.75/1.75 1.75/1.75 1.75/1.75 1.75/1.75 1.25/1.25 2/2 1.25/1.25 2/2 Calc. Min / Max Thrust (2000's LBS.)
1.55/4.13 1.55/4.13 1.55/4.13 1.55/4.13 8.78/24 8.78/14 8.78/14 8.78/14 Signature Thrust (IOOO's LBS.)
4.5 4.3 4.2 14.9 16.9 As Found Operable Yes Yes Yes Yes Yes Yes Yes Yes Teot Method, Description and Justification *** Full DP Full DP Full DP Full DP Full DP Full DP Full DP Full DP
- Torque switch. Minimum and maximum required settings at 80 and 100% of rated voltage are based on calculations by a vendor.
Signature thrust obtained by Point Beach stem thrust measurement system with no differential pressure.
- Full DP indicates functional test for operability at indicated differential pressure per part b of 85-03.
- Signature thrust obtained by Point Beach stem thrust measurement system with indicated differential pressure.
- Opened as required to perform safety function. Would not close.
Motor replaced.
5
e d
MOTOR > PERATED VALVE DATA
SUMMARY
RESPONSE TO IE7 825 **3
~
POINT BEACH NUCLEAR PLANT. UNITS 1 AND 2 JUNE 30.1988 Valve I.D.
1-826A 2-826A Valve Mfr.
Aloyco Aloyco Valve Type Gate Gate Valve Model 216-VGS-SP 216-VGS-SP Valve Size 8"
8" Rating 150#
1508 Operator Mfr.
Limitorque Limitorque Model SMB-00 SMB-00 Motor RPM 1800 1800
+
l Output Spd.*/an 52.5 52.5 Valve Function Normally Open.
Must remain open to supply high head safety injection pumps from RWST.
Design Delta P Open/Close(psid) 200/200 200/200 Maximum Delta P Open/Close(psid) 12/12 12/12 Tcst Delta P Open/Close(psid) 10.43/10.43 26.4/26.4 Prior Settings *
(Open/Close) 1.5/1.5 1.5/1.25 Final Settings (Open/Close) 1.75/1.75 1.5/1.25 Min. Setting (Open/Close100%)
1.25/1.25 1.25/1.25 Max. Setting (Open/Close1004) 3.25/3.25 3.25/3.25 Max. Setting (Open/Close 804) 2.25/2.25 2.25/2.25 Calc. Min / Max Thrust (1000's LBS.)
1.7/9.4 1.7/9.4 Signature Thrust (2000's LBS.)
5.3 As Found Operable Yes Yes Test Method, Description and Justification ***
Full DP Full DP Torque switch.
Minimum and maximum required settings at 80 and 100% of rated voltage are based on calculations by a vendor.
Signature thrust obtained by Point Beach stem thrust measurement system with no differential pressure.
- Full DP indicates functional test for operability at indicated dif ferential press 9tre per part b of 85-03.
6
M0V DATA
SUMMARY
COMMENTS SECTION The following section provides discussion on the Data Summary Table for IEB 85-03 Response OPEN AND CLOSED' TORQUE SWITCH SET HIGHER THAN RECOMMENDED Valves 0-4020, 0-4021, 0-4022, and 0-4023 required setting the torque switches higher than recommended to achieve the required thrust to close the valve under maximum delta P conditions.
The spring pack curve used by Limitorque in specifying torque switch settings is in error. We are currently working with Limitorque to resolve this discrepancy.
The spring packs will most likely be replaced with the n9xt stiffer spring pack to allow reduction in torque switch settings.
OPEN AND CLOSED TORQUE SWITCH SET LOWER THAN RECOMMENDED Valves 1-2019, 1-2020, 2-2020, 1-4000, 1-4001, 2-8788, 1-878C, and 1-8780 required the torque switch setting be lower than recommended to provide the required thrust.
Torque switch settings are lower than recommended to develop the required thrust due to the difference in stem to stem-nut friction factors.
The recommended settings are based on an assumed coefficient of friction of 0.2.
The actual coefficient of friction based on actual measurement is much less.
OPEN TORQUE SWITCH SET HIGHER THAN RECOMMENDED Valves 1-4006, 0-4009, 0-4016, and 2-896B have the open torque switch set higner than recommended.
The torque switch is not normally the limiting switch for valve travel in the open direction.
On opening, the open limit switch stops valve travel.
If the limit switch were to f ail, the torque switch would operate to limit valve travel.
Operators in the control room would also be alerted to the limit switch failure due to extended inter-mediate position indication. Analysis indicates that no valve or operator component failures would occur as a result of open limit switch failure; even during a 110% overvoltage condition.
TORQUE SWITCH SET AS RECOMMENDED, THRUST EXCEEDS RECOMMENDED Valves 2-4000, 2-4001,1-878B, 2-878B, 2-878C, ?.-8780,1-866A and 1-8668 have the torque switches set within the recommended range but have a thrust which exceeds the recommended maximum thrust on the operators. This difference is attributable to a stem to stam-nut coefficient of friction.
The reconaended f
I thrust on the operators is not based on fragility testing but rather on signature testing and experience.
It has been Point Beach experience that SMB-00 operators can typically sithstand more than 24,000 pounds of thrust with no degradation in function.
Many operators have been set at these higher level for 17 years.
There is no p,oblem with the valves at the current thrust level setting.
However, the settings will be lowered to be within the recommended thrust band at the next maintenance interval.
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TORQUE SWITCH SET HIGH, THRUST EXCEEDS RECOMMENDED Valves 1-878A, 2-878A, and 2-8780 have torque switch settings which are higher than recommended and calculated thrusts which exceed the recommended maximum thrust.
The recommended thrust for these valves is 14,000 pounds and is based on the operator testing mentioned above.
The calculated thrust is 18,700 pounds at the current switch settings.
This presents no problem for the valve itself and based on the discussion above presents no problem for the operator.
However, the settings will be lowered to be within the recommended thrust band at the next maintenance interval.
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