ML20046B349
| ML20046B349 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/19/1993 |
| From: | Buckley M, Eapen P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20046B339 | List: |
| References | |
| 50-334-93-11, 50-412-93-12, GL-89-10, NUDOCS 9308040104 | |
| Download: ML20046B349 (8) | |
See also: IR 05000334/1993011
Text
{{#Wiki_filter:_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1 . U. S. NUCLEAR REGULATORY COMMISSION REGION I Report Nos. 50-334/93-11 50-412/93-12 Docket Nos. 50-334 50-412 License Nos. DPR-66 NPF-73 Licensee: Duquesne Light Company One Oxford Center 301 Grant Street Pittsburgh, PA 15279 Facility: Beaver Valley Power Station, Units 1 and 2 Location: Shippingport, Pennsylvania Inspection Period: May 17 - 21,1993, and May 25 - 28,1993 ) June 7 - July 13,1993, at the regional offices ' l Contributor: R. Paroby, Co-op Engineering Assistant i
Inspector: , .14 , c C " / 1 /2 / e4 f 7N O /3 ~ ~ ~ ' Michael Buckley, Reactor Enginect] Date , Systems Section, EB, DRS N,{ '/////f 7 / anroved By: l Dr. P.K. Eapen, Chief, Systems Section D' ate Engineering Branch, Division of Reactor Safety ' 9308040104 930728 PDR ADOCK 05000334 O PDR _ _ _ _ _ _ - _ - _ _ _ _ _ - _ _ - - _ .. . .
. .- -. -.- . - . - _. . . . . , DETAILS , I 1.0 INSPECTION SCOPE This announced safety inspection was conducted to followup on and assess the ongoing
development and implementation of the licensee's actions in response to NRC Generic Letter ! ' ' 89-10, " Safety-Related Motor-Operated Valve Testing and Surveillance." This was accomplished by a review of open items, procedures and testing documentation, and i observation of testing activities. 2.0 MOV TEST OBSERVATIONS The inspector reviewed the licensee's methodology for performing design-basis diagnostic j testing of safety-related motor operated valves (MOVs). The licensee uses general l procedures for setting up MOVs prior to testing and to perform static testing. A specific test } procedure is used for dynamic testing each of the valves in the Generic 12tter 89-10 l program. The licensee has attempted to ensure that the conditions of dynamic testing reflect ! I the design-basis differential pressure and the maximum flow achievable. I During this inspection, Beaver Valley Unit I was shutdown for refuel and maintenance. There were 65 static and 13 dynamic tests conducted for the Generic Ixtter 89-10 program
j MOVs. The inspectors observed static tests on ICH-MOV275C, and IFW-MOV151C and dynamic testing of 1RW-MOV113C as detailed below.
2.1 IFW-MOV151C IB Steam Generator (SG) Auxiliary Feed Water Throttle Valve - l The SG Auxiliary feedwater throttle valve receives an automatic open signal which locks in ) for the first 30 seconds when the auxiliary feed water (AFW) Pumps are required. The ! valve is used to throttle AFW pump flow to SG IB and may be required to be~ positioned full
open or full closed. The inspectors observed the preparation and testing on this 3" Copes Vulcan globe valve. ! The maximum torque switch setting limit was 2.25 as stated in Procedure 1/2 CMP-75- l' MOVATS-1E, " Testing of Motor Operated Valves using MOVATS," and on the MOV Test Data Review Sheet. During testing, the torque switch was taken above this limit and caus:xt -{ the anti-rotation device, on the stem of the valve, to be overtorqued during a test stroke. j Thrust values remained within acceptance criteria. The as-left setting was 2.75 for this j valve. Neither Nuclear Engineering Department (NED) nor electrical maintenance
supervision was informed when the torque switch setting was taken above 2.25, the maximum specified in the procedure. It was the perception of the technicians that NED l ! would resolve the torque switch limit during review. The inspector noted that a limiter plate was not installed on the torque switch. Subsequent inspection by the licensee indicated no , detectable' damage of the anti-rotation device. The torque switch setting was lowered. slightly l below 2.75 to bring torque levels within acceptable limits. i
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, . 3 The overtorque of the anti-rotation device on this valve, during testing on May 4,1993 and again on May 26,1993, was caused by exceeding the torque switch limit specified in the test procedure. The licensee did not document the impact of this overtorque on other subcomponents within the valve. This is the first example of a lack of test control and a violation of 10 CFR Part 50, Appendix B, Criterion X1 " Test Control" requirements. (Violatica 50-334/93-11-01,50-412/93-12-01) 2.2 ICH-MOV275C Charging Pump IC Minimum How Isolation Valve The charging pump IC minimum flow isolation valve is a 2" Velan globe valve which is normally open and required to be closed during safety injection to insure total flow injection to the safety injection paths. 'Inis valve is closed remotely from the control room and does not receive a safety injection signal. A static test was performed on May 19,1993, as part of post maintenance testing to ensure ! satisfactory performance after the spring pack and torque switch were replaced on the [ Limitorque SMB-00 actuator. The manufacturer's (Limitorque) recommended thrust limit for this actuator is 14,000 lbs. Limitorque Technical update 92-01 subsequently allowed the
increase of this actuator's thrust limit to 19,600 lbs. Based on this new information the
licensee established an administrative limit of 18,275 lbs. to accommodate the instrument' ! accuracy of their diagnostic equipment. While stroking the valve in the open direction the
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actuator was subjected to an overthrust of 1250 lbs. above the 18,275 lbs. administrative ' thrust limit but, without exceeding the manufacturer's torque limits. This overthrust condition was analyzed by Nuclear Engineering Department (NED) and inaccurately , dispositioned as less than 2% while the actual overthrust of the administrative limit was > approximately 6.8%. The recommendations of Limitorque Technical Update 92-01 are
implemented in Procedure 1/2 CMP-75-MOVATS-lE, " Testing of Motor Operated Valves using MOVATS. This is the second example of a lack of test control and a violation of 10 t CFR Part 50, Appendix B, Criterion XI " Test Control" requirements as discussed in Section - 2.1. 3.0 TEST RESULTS REVIEW ! The inspector reviewed MOV test results to determine if testing was being conducted in accordance with approved procedures and if tested MOVs could perform satisfactorily in ! 4 service and during accident conditions. Documentation for selected motor-operated valves (IRW-MOV113B, lQS-MOV101 A, IRC-MOV536, 2RCS-MOV535, 2CHS-MOV310, and , 2CHS-MOV381) was reviewed. The review of the documentation of the above MOVs found ' minor attention to detail discrepancies which the licensee agreed to address. The inspector did not identify any significant concerns regt.rding the testing and evaluation of these valves. _ 1 ! ! 4 i I
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~ ! A review of the testing schedule indicates that the licensee may have difficulty in meeting their commitment for full implementation of the Generic letter 89-10 Program without an l extension. The licensee is reviewing this matter for resolution. ] 4.0 ICH-MOV142 RESIDUAL HEAT REMOVAL LETDOWN TO NON- j RESENERATIVE HEAT EXCHANGER IN FLOW CONTROL VALVE j , The residual heat removal letdown primary containment isolation valve is required to close
prior to entering Mode 4 operation. During operation in Modes 1 though 4 this valve is !
closed and deenergized. A Limitorque Modutronic control unit is mounted on the valve to provide an automatic throttling capability during shutdown operation. Preparations for diagnostic testing done on May 16, 1993, required bypassing of the limit 1 switches to test the torque switch. The torque switch was also bypassed to perform the l torque switch verification step by holding open the torque switch while power is supplied to l i the motor. While the torque switch was bypassed the technician did not have a means of ' quickly removing power from the valve operator. _ This resulted in the motor driving the stem into the seat with the maximum output of the motor. The thrust from the valve operator l seriously bent the stem and overstressed the split clamp and actuator stem. The licensee evaluated the component for overtorque and overthrust conditions. The i i licensee's immediate corrective actions were to replace the stem / stem plug, stem nut, actuator stem, torque switch, and split clamp. The valve was setup in accordance with the Manufactures Technical Manual and the torque switches set at 2.0 in the open and closed l ! directions. The valve has passed a Type C leak rate test and an operational surveillance test. The licensee also observed the valve in operation. A weak leak analysis was completed and all degraded components were replaced. The licensee has placed a hold on the testing of l Modutronic operators until improved testing techniques are developed and personnel trained. l i The guidelines and precautions on adjusting thrust settings were re-emphasized by- supervision to the field technicians. l The lack of test control which allowed the bending the stem and other damage to ICH- MOV142 is the third example of the violation of 10 CFR Part 50, Appendix B, Criterion XI requirements discussed in Section 2.1. . i 5.0 SB-00 ACTUATORS l The inspector reviewed the licensee's actions with regard to Limitorque SB-00 actuators. Specifically, the potential for a Part 21 Report on drive sleeve material and the actions taken i in response to a previously identified unresolved item were reviewed. 5.1 Drive Sleeve Material (Unresolved Item 92-80-1 (open)) On April 17, 1992, the drive sleeve on 2 SIS-MOV867D failed during a static MOVATS test.
. ll . 5 At the time the operator thrust was approximately 15,500 lbs. The drive sleeve material was analyzed and found to be made from gray cast iron rather than the vendor specified malleable iron. Limitorque's opinion that a broken drive sleeve does not affect the operability of the MOV was stated by a letter dated July 22,1992. Limitorque's position appears reasonable.
I , t 1 i f r y
. I 4 6 Since this condition could have possibly affected other SB-00 actuators, the licensec j evaluated the applicability of a Part 21 Defect or Noncompliance Report. Beaver Valley has 29 SB-00 actuators at Unit 2 and 2 at Unit 1. An inspection verified that the drive sleeves of the Unit I actuators were made from the correct material. The licensee plans to inspect several of the affected Unit 2 valves during the next refueling outage. The licensee concluded that the wrong drive sleeve material in 2 SIS-MOV867D was an isolated , instance and it did not cause a significant safety hazard. Therefore, the licensee did not initiate a Part 21 Report. i During the NRC inspection 50-334,412/92-80, the inspectors observed that the thrust rating was extended beyond the manufacture's specified limit. Specifically, a Westinghouse letter, dated October 28,1992, extended the thrust rating of Limitorque type 00 operators to 16,000 lbs. These operators were originally rated for a maximum thrust 14,000 lbs. The increased thrust rating was justified by a qualification program conducted by Limitorque for Westinghouse and documented in report 541-V-38380. However, a copy of this report was not available on site for review at the time of this inspection. This item remains open pending the licensee's action to obtain the test report that justified the extended thrust limit for this actuator. 6.0 LIMITORQUE PA'RT 21 NOTIFICATIONS The inspector reviewed the licensee's actions in response to the following Limitorque Part 21 Notifications. i l 6.1 92-2 SBD-1 IIousing Cover Screws (closed) The licensee stated that since no SBD-1 actuators are installed at Beaver Valley, no action was necessary. The inspector verified that the licensee had no SBD-1 actuators by reviewing , the Master Equipment List and Attachments A and B of the Maintenance Manual. This item I is closed. ' 6.2 92-3 Declutch System Anomaly (closed) l The licensee reviewed all type 00 and 000 category 1 operators at Units 1 and 2. Valves were considered susceptible to the declutch system anomaly if: (1) the valve receives an I automatic signal to change position; (2) a stress analysis on the actuator indicates the vibration characteristics identified in the Part 21 Notification; and (3) a 15 second increase in stroke time, based on the length of a seismic event, affects the operating requirements of the l l valve. This licensee identified 10 Unit 1 MOVs in the control room ventilation system susceptible to the concern. A detailed analysis determined that a delay in the operation of 4 l
. _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ , . . 7 these valves due to a seismic event does not create a significant safety hazard. Therefore, the licensee concluded that no action in response to this Part 21 notice was necessary. The inspector verified that the licensee's resolution was appropriate and independently reviewed the analysis of the 10 Unit 1 MOVs. This item is closed. 7.0 CONCLUSIONS The licensee was continuing to meet the recommendations of Generic Ietter 89-10 with the exceptions discussed below. Several weaknesses were identified in the licensee's MOV testing program. During diagnostic testing valves ICH-MOV142 and 1FW-MOV151C were overthrusted and overtorqued, respectively. This indicates a lack of test control in that the stem on ICH-MOVl42 was bent and IFW-MOV151C has been overtorqued twice in the same outage. A lack of test control was also demonstrated by the inaccurate dispositioning of the overthrust condition for 1CH-MOV-275C. Additionallicensee attention is required to: (1) review the completion schedule against Generic 12tter 89-10 program commitments, (2) evaluate design-basis differential pressure calculations to assure that design-basis conditions are realistic, and (2) provide justification for the thrust rating of SB4)0 actuators. 8.0 EXIT MEETING The inspector met with those denoted on Attachment A on May 28,1993, to discuss the preliminary inspection findings as detailed in this report. The licensee did not indicate that this inspection involved any proprietary information. l l l _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .
_ _ _____ . - ___- -__ -_ _ _ . . . i
l ATTACHMENT A , i MOV Follow-up Inspection PERSONS CONTACTED Duquesne Light Company ,
- E.
Coholich Sr. Licensing Supervisor
- C.
Custer Director Component Engr.
- S.
Fenner General Manager Maintenance Programs l
- L.
Freeland General Manager Nuclear Operations ' K. Grada Manager QSU
- K.
Halliday Director Elect. Engr. NED S. Koren Electrical Maint. Foreman
- E.
I.ars Supervisor Comp. Elec. Engr.
- G.
Lauch Supervisor Elect. Maint. Engr.
- F. Lipchick
Sr. Licensing Supervisor
- S.
Lochlein Supervisor Mech. Components Engr. D. McLain Manager Maint. Engr. & Assessment A. Mizth Quality Services Unit
- N.
Morrison Senior Engineer NED
- T.
Noonan General Manager Nuclear Engr. and Safety
- K.
Ostrowski Operations Manager, Unit 1 M. Paulick Manager Maint. Plan. and Admin. i
- M.
Pettigrew Supervisor Systems Engr.
- R.
Sepelak Licensing Engineer
- M.
Siegel Manager Nuclear Engr. P. Swiech Electrical Maint. Foreman
- D.
Spoerry V.P. Nuclear Operations l
- G.
Thomas D.V.P. Nuclear Services
- N.
Tonet Manager Nuclear Safety
- R.
Zabowski Director System Engr.
i l U.S. Nuclear Regulatory Commission l
- L.
Rossbach Senior Resident Inspector, Beaver Valley P. Sena Resident Inspector, Beaver Valley
- Denotes those personnel attending the exit meeting on May 28,1993.
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