PLA-3660, Forwards Calculations to Support Available Valve Factors,Per Commitment Made During Insp of Generic Ltr 89-10,Suppl 3 During Wk of 910923
| ML18030A077 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 10/04/1991 |
| From: | Keiser H PENNSYLVANIA POWER & LIGHT CO. |
| To: | Butler W Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML17157A872 | List: |
| References | |
| GL-89-10, PLA-3660, NUDOCS 9110100045 | |
| Download: ML18030A077 (7) | |
Text
ACCELERATED D?
UTION DEMONS TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9110100045 DOC.DATE: 91/10/04 NOTARIZED: NO FACIL:50-387 Susquehanna Steam Electric Station, Unit 1, Pennsylva 50-388 Susquehanna Steam Electric Station, Unit 2, Pennsylva AUTH.NAME AUTHOR AFFILIATION KEISER,H.W.
Pennsylvania Power
& Light Co.
RECIP.NAME RECIPIENT AFFILIATION BUTLER,W.R.
Project Directorate I-2 DOCKET 05000387 05000388 NOTES:LPDR 1
cy Transcripts.
LPDR 1 cy Transcripts.
RECIPIENT ID CODE/NAME PD1-2 LA RALEIGH,J.
COPIES LTTR ENCL 1
0 1
1 RECIPIENT ID CODE/NAME PD1-2 PD
SUBJECT:
Forwards calculations to support available valve commitment made during insp of Generic Ltr 89-10 during wk of 910923.
DISTRIBUTION CODE:
A064D COPIES RECEIVED:LTR Q ENCL g TITLE: Response to Generic Ltr 89-10, "Safety-Related MOV COPIES LTTR ENCL 1
1 D
D factors,per I
,Suppl 3
D SIZE: 4+54 S
Testing
& Surveill /
05000387 05000388 A
INTERNAL: ACRS NRR GODY,A., JR NRR/LPEB/BC RES/DSIR/EIB/B EXTERNAL: NRC PDR NOTES:
1 1
1 1
1 1
1 1
1 1
2 2
BAER,B RES NRR/DE+/+ EB 7E RE~'TLE NSIC 1
1 1
1 1
1 R
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NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACI'HE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAMEFROM DISTRIBUTION LIP% FOR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 14 ENCL 13
Pennsylvania Power 8 Light Company Two North Ninth Street ~Allentown, PA 18101-1179 ~ 215/774-5151 Harold W. Kelser Senior Vice President-Nuclear 215/7744194 OCT 0 4 19Sl Director of Nuclear Reactor Regulation Attention: Dr. W.R. Butler, Project Director Project Directorate I-2 Division of Reactor Projects U.S. Nuclear Regulatory Commission Washington, D.C.
20555 SUSQUEIIANNA STEAM ELECTRIC STATION GL 89-10 SUPPLEMENT NO. 3-AVAILABLEVALVEFACTORS PLA-FILE R41-2 Docket Nos. 50-387 and 50-388
Dear Dr. Butler:
As part ofthe NRC Team Inspection on Generic Letter 89-10 conducted at Susquehanna SES during the week of September 23rd, Pennsylvania Power & Light Company committed to provide calculations showing the available valve factor for each of the GL 89-10 Supplement No. 3 valves.
The available valve factors are attached.
The calculations to support the available valve factors are also attached.
Also, as part of the Team Inspection, the NRC requested that PP&Lprovide a date when the Impell recommendations from their analysis of the Susquehanna SES Supplement No. 3 valves would be dispositioned.
The Impell recommendations (with the exception of Recommendation ¹3 which is still under evaluation) are dispositioned per the attachment.
Ifyou have any questions, please contact Mr. C.T. Coddington at (215) 774-7915.
Very truly yours, H. W. Keiser Attachments 9ii0100045 9ii004 PDR ADOCK 05000387 I't:
PDR FILE R41-2 PLA-3660 Dr. W. R. Butler CC:
<NRC33ocument Control-Desk-(origina~l)
NRC Region I Mr. G.
S.
Barber, NRC Sr. Resident Inspector Mr. L.
Prividy, NRC Region I Mr. J.
J.
Raleigh, NRC Project Manager Mr. T.
G. Scarbrough, NRC NRR
Summary of Available Valve Factors Tag Number Available Valve Factor Using Nominal MotorTorque Rating (ACMOVs Only)
Available Valve Factor Using Actual MotorStall Torque From a Typical Motor Curve (ACMOVs Only)
Available Valve Factor Using Available MotorStart Torque (DC MOVs Only)
RWCU HV-144F001 HV-144F004 HV-244F001 HV-244F004 0.95 N/A N/A 1.2 N/A 1.27 N/A N/A N/A RCIC HV-149F007 HV-149F008 HV-249F007 HV-249F008 0.66 N/A 0.66 N/A N/A N/A N/A 152 N/A 152 HPCI HV-155F002 HV-155F003 HV-255F002 HV-255F003 339/.385 (Sce Note 4)
N/A 366/.415 (Sce Note 4)
N/A
.422/.477 (Scc Note 4)
N/A
.454/513 (Scc Note 4)
N/A N/A 0.87 N/A 083 NOTES:
- 1. Calculations forACMOVswere performed using both motor nameplate torque rating and actual expected motor start torque from typical motor curves.
- 3. Unless otherwise noted, calculations used:
Stall efficiencies Application factor of,.9 Stem coefficient of frictionof0.15 Mean seat contact diameter Actual voltages available at the time ofvalve seating
- 4. For purposes ofcomparison, thc limitingvalve factors for the HPCI F002 valves were also calculated without usc of a.9 application factor. Thc application factor is in part an attempt to account for minor voltage fluctuations. Since a seperate voltage correction factor is already being applied it is overly conservative to also use an application factor of 0.9.
- 5. Thc available valve factor results forHV-155F002 are slightlydifferent than those previously given to the NRC. This is due to a rcccnt revision to the available voltage calculations.
Disposition to Impell Recommendations With Regards to Generic Letter 89-10 Supplement 3 Motor Operated Valves Recommendation Number 1:
Ensure/verify that the closed-direction torque switch bypass is set at 95% or greater ofvalve closure. Procedural enhancements may be necessary to permit quantifying the amount of stem movement between switch actuation points.
PPAL Disposition:
PP8cL's philosophy, as stated in Mechanical Design Standard 03, is that the torque switch be bypassed 97% of travel on motor-operated valves (MOVs) with a closed safety function. The individual MOVData Detail Drawing for each of the subject MOVs speciTies a close torque switch bypass setting of 97% closed.
Specifications M-1498 (Field Implementation of the SSES MOVProgram) and M-1496 (Documentation and Control ofMOVTorque Switch and Geared LimitSwitch Set Points) specify the requirements for field verification of limitswitch setpoints and control of the settings once established.
The requirements of these two specifications are incorporated into Maintenance Procedure MT-GM-050. This procedure provides the requirements for quantifying and verifying the amount of stem movement between torque switch bypass actuation and torque switch trip. This verification has been completed for all Unit2 Supplement 3 MOVs and will be completed for the Unit 1 counterparts during the U1-6RIO (First quarter 1992).
Recommendation Number 2:
Ensure maximum operator torque to thrust conversion by maintaining cleanliness and lubrication of the valve stem and stem nut on a specified periodicity.
PPAL Disposition:
Prior to the'end of the Unit 1-6RIO, all Supplement 3 MOVs willhave had their stems lubricated since the issuance of this recommendation.
Furthermore, the lubricant used by PP&L has been shown to provide
superior lubricating characteristics to other available lubricants. This has been confirmed by the EPRI grease testing project.
AilMOVs are currently undergoing review as part of PP&L's Preventative Maintenance Improvement Program (PMIP). This program uses Reliability Centered Maintenance (RCM) methodology to review and evaluate:
SSES and industry component failures Existing PM, EQ, and surveillance activities Vendor and industry recommendations PP&L mandated requirements One of the outcomes of this program, to be completed by the end of 1991, willbe the specification of a stem re-lubrication frequency.
Recommendation Number 3:
For the RWCU Outboard valves, the torque switch should be set to the maximum setting, to ensure adequate torque and thrust output, regardless of conditions.'or the inboard valves, the torque switch settings should be increased to provide approximately 175 to 185 ft-lbs of torque at torque switch trip. For the long term, it is recommended that the inboard valves have the spring pack replaced with the "Heavy" spring pack, and the torque setting decreased to provide 175 to 185 ft-Ibs torque at torque switch trip.
PP&L Disposition:
PP&L is currently pursuing obtaining results of recently completed actuator thrust re-qualification efforts for Limitorque SMB-00 actuators.
Until these results can be obtained and reviewed for acceptability, the torque switch settings cannot be adjusted beyond the point where the delivered thrust exceeds the actuator thrust rating, An effort is also underway to work with the valve manufacturer to develop weak linkanalysis for the subject MOVs, The results of this effort along with the expected increased actuator thrust limitwillbe used to increase the range of acceptable torque switch settings and raise the allowable thrust upper limit. In conjunction with this, consideration willbe given to the future installation of the "Heavy" spring pack on the inboard valves.
Aschedule is currently being developed for performance of the weak link analysis and procurement of the actuator requalification results. This schedule willbe dependent on the valve manufacturer's ability to prepare the weak linkanalysis in a timely manner. Until these efforts are complete,
PPAL cannot commit to an implementation schedule for Impell's recommendation to raise the torque switch setting on the RWCU outboard valves to their maximum value.
Recommendation Number 4:
For the Unit2 RCIC outboard valve, itwould be prudent to increase the torque switch setting to be consistent with the Unit 1 RCIC outboard valve, to ensure future valve operator or stem lubrication degradations do not hinder the abilityof the valve to close.
PPAL Disposition:
The close torque switch setting on the Unit2 RCIC outboard valve (HV-249F008) has been set to its maximum allowed torque switch setting (2.75 with a 0301-112 spring pack).
Recommendation Number 5:
For all of the operators, some confirmation is needed that the existing torque switch settings are permitting the operators to develop their fullthrust capability. This may be accomplished through the use of thrust measuring equipment or by verifying proper torque by use of a torque wrench.
PPAL Disposition:
AllGL 89-10 Supplement 3 MOVs willhave been initial baseline VOTES tested prior to the end of the Unit 1-6RIO. Any modifications or changes in the torque switch setting or minimum required thrust would necessitate that the baseline be re-established.