IR 05000219/1998007: Difference between revisions
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{{Adams | {{Adams | ||
| number = | | number = ML20236L847 | ||
| issue date = | | issue date = 07/02/1998 | ||
| title = | | title = Insp Rept 50-219/98-07 on 980615-19.No Violations Noted. Major Areas Inspected:Status of Plant motor-operated Valve Program to Determine Acceptability for Closure of NRC Review Under GL 89-10 | ||
| author name = | | author name = | ||
| author affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) | | author affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) | ||
| addressee name = | | addressee name = | ||
| addressee affiliation = | | addressee affiliation = | ||
| docket = 05000219 | | docket = 05000219 | ||
| license number = | | license number = | ||
| contact person = | | contact person = | ||
| document report number = 50-219-98-07, 50-219-98-7, NUDOCS | | document report number = 50-219-98-07, 50-219-98-7, GL-89-10, NUDOCS 9807130203 | ||
| | | package number = ML20236L831 | ||
| document type = | | document type = INSPECTION REPORT, NRC-GENERATED, TEXT-INSPECTION & AUDIT & I&E CIRCULARS | ||
| page count = | | page count = 13 | ||
}} | }} | ||
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U. S. NUCLEAR REGULATORY COMMISSION | |||
Oyster Creek Nuclear Generating Station | ==REGION I== | ||
Report No: 98-07 Docket No: 50-219 License N DPR 16 Licensee: GPU Nuclear incorporated 1 Upper Pond Road Parsippany, New Jersey 07054 Facility Name: Oyster Creek Nuclear Generating Station | |||
- Location: Forked River, New Jersey inspection Period: June 15 - 19,1998 Inspector: Douglas Dempsey, DRS Participating Personnel: Thomas Scarbrough, NRR/EMEB Approved By: Eugene M. Kelly, Chief Systems Engineering Branch Division of Reactor Safety l | |||
9807130203 900702 PDR ADOCK 05000219 G PDR , | |||
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EXECUTIVE SUMMARY Oyster Creek Nuclear Generating Station Report No. 50-219/98-07 This inspection reviewed the status of the Oyster Creek motor-operated valve (MOV) ; | |||
program to determine its acceptability for closure of the NRC's review under Generic Letter q | |||
(GL) 8910, " Safety-Related Motor-Operated Valve Testing and Surveillance." Progress . | |||
has been made, and the quality of calculations and supporting technical evaluations in the program were good. However, the NRC was unable to reach closure regarding the review due to the large proportion of MOVs in the program for which modifications and updated calculations remain to be complete * Although action plans were tracked and scheduled, the licensee had not yet adequately verified the design basis capability of approximately two-thirds of the valves in its GL 89-10 program. This included all of the twelve risk-significant high energy line break isolation valves at Oyster Creek. However, the inspectors found i current MOV functionality to be acceptable, based on independent evaluation of industry data. GPUN performed acceptable technical evaluations of load sensitive behavior, stem friction coefficient, and dynamic unwedging thrust requirement (Section E1.1) | |||
* In evaluating the operability of containment spray valves V-21-5 and V-21-11, GPUN used an inadequately validated method to reduce perceived conservativisms in the Electric Power Research Institute MOV Performance Prediction Methodolog , | |||
However, the licensee adequately justified current MOV functionality by other means. (Section E1.2) | |||
* GPUN conducted a thorough and self-critical assessment of the Oyster Creek GL 8910 MOV program. Deficiencies identified by the self-assessment team were addressed adequately. (Section E7.1) | |||
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Report Details 111. Enaineerina j E1 Motor-Operated Valve Program Review (Tl 2515/109) | |||
. E Justification of MOV Prooram Assumptions Insoection Scope | |||
- On June 28,1989, the NRC issued Generic Letter (GL) 89-10, " Safety-Related Motor- ; | |||
Operated Valve Testing and Surveillance," which requested licensees to establish a | |||
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program to ensure that switch settings for safety-related motor-operated valves (MOVs) | |||
were selected, set, and maintained properly. Seven supplements to the GL have been issued to provide additionalinformation and guidance on development of program . Previous inspections at the Oyster Creek Nuclear Generating Station were conducted based on guidance contained in NRC Temporary Instruction (TI) 2515/109," Inspection Requirements for Generic Letter 89-10." | |||
The purpose of this inspection was to examine the actions implemented at Oyster Creek (OC) and to determine if those actions were sufficient to warrant closure of the NRC staff review of the GL 89-10 MOV program. The inspection was focused primarily on risk- | |||
, | - significant high energy isolation valves in the reactor water cleanup and emergency condenser systems. The engineering evaluations, topical reports, modification packages, and calculations reviewed during the inspection are listed at the end of this inspection l report. The inspectors verified current valve operability by performing independent calculations of thrust requirements and motor-actuator capabilities, Observations and Findinas Overall Proaram Status There are'27. valves in the GL 8910 program at Oyster Creek. The licensee (GPUN) had ! | ||
not completed all of its planned actions to demonstrate design basis capability for two l thirds (18) of the valves in the program. Nine valves in the reactor building closed cooling water, shutdown cooling, and containment (torus) cooling systems fully satisfied design basis thrust requirements based on dynamic tests and a grouping method that was consistent with the recommendations in Supplement 6 of GL 89-10 for sample siz . Thrust calculations using the Electric Power Research Institute (EPRI) MOV Performance Prediction Methodology (PPM) were completed for eight valves in the emergency | |||
. condenser (EC) and containment (drywell) spray systems.' Draft PPM calculations for the four high energy line break containment isolation valves in the reactor water cleanup (RWCU) system were in the design review process at the time of the inspection, and were | |||
- scheduled for completion in time to support valve internals modifications during the upcoming (Fall 1998) refueling outage. PPM calculations for the remaining six emergency condenser and core spray system valves also were in draft form. The licensee has scheduled the latter valves for completion during the year 2000 refueling outage. GPUN | |||
. also committed to complete its structural (weak link) and stroke time calculations by the | |||
. end of the 1998 refueling outage. | |||
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- Valve Factor | |||
+ in inspection. Report 50 219/97-05,the NRC concluded that GPUN had not justified its j | |||
' valve factor assumptions for contestable valves adequately. In response to the NRC's { | |||
findings and the results of a subsequent MOV program self assessment, the licensee implemented or planned corrective actions for the valve groups discussed below. The inspectors verified that each item is being tracked by a Licensing Action Request (LAR). | |||
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* -Group 1 A consisted of three, six-inch,600 psi, Anchor-Darling flexible wedge gate valves in the RWCU system. The valves are required to close under blowdown | |||
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conditions to' terminate a high energy line break as discussed in Supplement 3 of | |||
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GL' 89-10. Originally, the licensee assumed a valve factor of 0.59 based on tests l performed by EPRI and other utilities. However, all but one of the 32 tests cited by (-. - the licensee were performed under pumped flow (rather than blowdewn) conditions, l and the information from two industry blowdown tests of Anchor-Darling valves 1 | |||
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. was not included in the data set. These two valves exhibited unpredictable L- behavior and suffered significant internal damag GPUN int' ends to modify the valve internals to meet PPM guidelines and to perform l PPM thrust calculations for the valves by the Fall 1998 (17R) refueling outage. In the interim, the inspectors considered the current valve actuator setups to be ] | |||
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acceptable. With the torque switches bypassed and degraded voltage motor | |||
- capability calculations that properly included elevated temperature effects, rate of loading, pullout efficiency, and a 0.9 application factor, the MOVs were capable of overcoming a 0.76 valve factor. | |||
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* - Group 1B consisted of six, eight-inch,600 psi, Anchor Darling flexible wedge gate | |||
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valves in the core spray system. The licensee plans to remove two of the valves | |||
' (V-20-12 and V-20-18) from the program on the basis of declaring the core spray system inoperable when the valves are closed for testing or maintenance. The basis for exclusion was consistent with GL 8910 guidance and acceptabl Per Engineering Evaluation.125.1 (File # 0235-97)," Gate Valve Factor By Grouping," the licensee assumed a valve factor of 0.7 for this group. GPUN also | |||
= previously had agreed to maintain an available thrust margin of at least 18,000 pounds-force (lbf) above running load. The valve factor assumption was based on the highest valve factor observed during tests of similar valves at another plan However, since the licensee did not perform a rigorous engineering review of these tests, the inspectors considered the assumption to be acceptable only for interim operability. Based on the current torque switch settings and measured running loads, and accounting for rate of loading and diagnostic uncertainties, the MOVs are | |||
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capable of overcoming a valve factor of approximately on * Group 1C consisted of two,10-inch,600 psi, Anchor-Darling flexible wedge gate | |||
. valves in the EC condensate return lines., GPUN plans to modify the valve internals | |||
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'and to perform PPM calculations by the year 2000 (18R) refueling outage. The deferral was unavoidable because the valve work requires a full core off-load to the i | |||
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spent fuel pool, which cannot be performed during the 17R refueling outage, in the interim, the MOVs are capable of overcoming a valve factor of 0.79 assuming the running loads and stem friction coefficients measured during the latest static i diagnostic tests. In addition, during the upcoming 17R refueling outage, the licensee plans to implement modification OC-MD-F383-001,"89-10,17R Cable & | |||
Conduit Modification," to increase the thrust margin of valve V-14-36 under degraded grid condition * Groups 2A and 2B consisted six,10-inch,900 psi, Anchor-Darling double-disk gate valves in the EC system. The licens0e performed EPRI PPM hand calculations to define the design basis thrust requirements for these high energy line break isolation valves. During a previous refueling outage, the licensee verified that the valve disks were oriented in the preferred direction in order to support the PPM calculation conclusions. GPUN plans to increase the design capability of valve V-14-30 (which had a design margin of only six percent) by replacing the motor power cable during' | |||
the.17R refueling outage. Pending implementation of the cable modification, the inspectors considered the MOVs in these groups to be acceptable for GL 89-10 ! | |||
program closur * Group 3A contained two,14-inch,150 psi, Ohio injector Company solid wedge gate valves in the drywell spray system. In its thrust calculations using the - , | |||
standard industry equation, the licensee used a valve factor of 0.6, based on l comparison with 12",150 psi, Anchor Darling valves. Subsequent review l confirmed that there were no significant differences between the valves. The licensee completed PPM calculations in late 1997. Since the disk and seat ring faces were not fabricated with PPM-validated materials (monel alloy 505 and satellite 7 versus satellite 6), the calculation's results are considered to be best available information, subject to long term validation through a test program. A O.62 valve factor was back-calculated from the PPM result As currently set up, the thrust capabilities of valves V-21-5 and V-21-11 were marginal. To demonstrate interim operability until the Fall 1998 refueling outage, the licensee used a statistical analysis to remove some of the perceived . | |||
" conservatism"in the EPRI model. As discussed in Section E1.2 of this report, the | |||
. inspectors considered the analysis to be unacceptable. However, using more standard methods based on measured (versus design basis) stem friction coefficients, packing loads, and rate of loading, the licensee was able to show that the valves were operable. GPUN plans to increase the torque switch settings for these valves during the 17R refueling outage, i | |||
. ' C Group 4 contained two,14-inch,900 psi, Velan flexible wedge gate valves in the shutdown cooling system.' Per Engineering evaluation 125.1 (File # O235-97), a valve factor of 0.8 was assumed based on a single in-situ dynamic test performed at 80% of design differential pressure (measured valve factor was 0.66), and industry tests of similar valves. The licensee did not perform a rigorous engineering review of the industry tests, and the inspectors did not consider the data to be adequate for design purpose . | |||
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The thrust capability margin of valve V-17-19 was acceptable (approximately 17%). | |||
l However, the current torque switch setting of valve V-17-54 was not adequate to meet the design basis valve factor assumption of 0.8; using measured (versus | |||
' design basis) values of rate of loading and packing load in the standard industry i equations, the available valve factor was 0.78 for this MOV. However, the MOV was capable using the tested valve factor of 0.66. During the 17R refueling outage, the licensee plans to bolster its valve factor assumption by dynamically testing both valve , | |||
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* . Group 6 consisted of two, four-inch,150 psi, Velan flexible wedge gate valves in the containment (torus) spray system. The licensee's 1997 self-assessment team j concluded that the assumed valve factor of 0.6 was not supported adequately b l the results of in-situ dynamic tests and industry data. The inspectors found that the i i valva Mpability margins were very low at the current torque switch settings if design basis rate of loading and packing load assumptions were used. However, _; | |||
using measured packing loads, an immediate operability concern does not exist with l the current torque switch settings. GPUN plans to dynamically test both valves ' | |||
during the 17R refueling outage to validate its valve' factor assumptio ! | |||
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l In summary, GPUN committed to perform the following actions during the Fall 1998 -] | |||
refueling outage: (1) modify valve internals and complete PPM thrust calculations for three | |||
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, RWCU system valves in Group 1 A; (2) adjust the torque switch settings for two drywell I spray system valves in Group 3A; (3) replace power cables for EC system valves V-14-30 l and V-14-36; and (4) and dynamically test four valves in the drywell spray and shutdown i cooling systems (Groups 6 and 4, respectively). GPUN also committed to modify valve internals and complete PPM thrust calculations for two EC system valves (Group 1C) and l to complete PPM calculations for 4 core spray system valves (Group 1B) during the year | |||
; 2000 refueling outage. The inspectors noted that the licensee's consideration of the limitations and conditions identified in the NRC safety evaluation of the EPRI PPM was not clear in all instance I Stem Friction Coefficient and Load Sensitive Behavior In NRC inspection Report 50-219/97-05,the NRC concluded that the GPUN's treatment of load sensitive behavior (aka " rate of loading") was not well supported by a statistically | |||
! significant amount of test data. In its August 5,1997 letter to the NRC, the licensee | |||
!: discussed a plan to obtain the necessary information from the EPRI PPM, and committed to I' incorporate the EPRI rate of loading methodology into its torque switch settings by the end of 1997, and to apply the methodology to its stroke time calculations by the end of the Fall 1998 refueling outage. In a letter to the NRC dated February 3,1998, GPUN indicated | |||
- that the justification for its rate of loading and stem lubricant degradation assumptions had , | |||
been completed.- | |||
The licensee described its justification for the stem friction coefficient and rate of loading assumptions in Engineering Evaluation 125.1 (File # 230-97)," Generic Letter 89-10 MOV Stem Factor and Rate of Loading," dated December 11,1997. Where possible, actual stem friction coefficients of less than 0.15 were verified during static diagnostic tests. To | |||
' account for the effect of !oad sensitive behavior, the licensee typically adds 0.046 to the b | |||
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measured static stem friction coefficient to estimate the coefficient that might result under dynamic conditions. If no valve-specific test data exists, the evaluation indicated that e O.-2 dynamic stem friction coefficient would be assumed, except in certain instances. In determining the minimum required static thrust set point, GPUN assumed a 5.3% leas and 19% random value for rate of loading based on its review of Oyster Creek, EPRI, and Boiling Water Reactor Owner Group (BWROG) test data. The licensee aLo assumed a 1.2% bias and 4% random value for lubricant degradation. GPUN also evaluated unwedging test data to support the absence of load sensitive behavior during this limited portion of a valve opening strok EPRI did not test the stem lubricant (Synco Chemical Company Super Lube EP 2) applied at Oyster Creek. The licensee evaluated the general differences in the Oyster Creek and EPRI stem greases to support its assumption that the lubricants will perform in a similar manner, and indicated that additional testing is planned to justify further its stem friction coefficient and rate of loading assumptions for its specific stem grease. Further, GPUN will need to continue to monitor test data to confirm its assumption of the absence of load sensitive behavior during gate valve unwedging. GPUN committed to specify its plans for obtaining additional test information to justify its stem friction coefficient and rate of loading assumptions for the stem grease used at O Unwednina Thrust Requirements in conducting its test program, EPRI determined that the thrust required to open gate valves under differential pressure conditions can exceed the thrust required to open those valves under static (zero differential pressuie) conditions. As part of the PPM, EPRI provided guidance for licensees using the methodology to estimate the thrust required to pull the discs out of the seats for wedge-type gate valves and Anchor-Darling double-disk gate valves. Unwedging thrust requirements are predicted separately from the thrust requirements to overcome dynamic flow effects obtained from the EPRI valve model In calculation C-1302-900-E54C 015," Motor Operated Valve (MOV) Unwedging Load, GL 89-10,"the licensee described its evaluation of the capability of motor actuators to unwedge the applicable MOVs in its GL 89-10 program. GPUN followed the approach outlined by EPRIin its topical report. The licensee will need to consider the effect of recently issued Limitorque Technical Update 98-01 on its prediction of motor actuator output for the evaluation of the capability of its safety-related MOVs to overcome unwedging loads (and other MOV operating requirements). Conclusions Although action plans were tracked and scheduled, the licensee had not yet adequately established the design basis capability of approximately two-thirds of the valves in its GL 89-10 program. This included all of the twelve risk-significant high energy line break isolation valves at Oyster Creek. However, the inspectors found current MOV functionality to be acceptable, based on independent evaluation of industry data. GPUN performed acceptable technical evaluations of load sensitive behavior, stem friction coefficient, and dynamic unwedging thrust requirements. | |||
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E1.2 EPRI Performance Prediction Methodoloav Thrust Uncertainty . Insoection Scope GPUN determined that containment (drywell) spray valves V 21-5 and V-21-11 were no able to' meet the thrust requirements predicted by the EPRI PPM. The licensee documented its operability determination for the valves in calculation C-1302-241-E310-083," Valves V-21-5 and V-21-11 Operability Calculation for PPM." The inspectors reviewed the calculatio Observations and Findinas The licensee used test results from the EPRI test program and derived a value for the | |||
. perceived conservativism in the output of the performance prediction model. GPUN then applied the derived quantitative value of "conservativism" as an uncertainty to reduce the predicted thrust requirement for valves V-21-5 and V-21-11. With the lower thrust requirement, the licensee concluded that the valves were operabl In its February 20,1997 Supplement to the Safety Evaluation (SE) on the EPRI PPM, the NRC stated that it had reviewed the EPRI methodology as a complete package in that cortain nonconservative assumptions in the models are compensated by other conservative assumptions in the analytical formulas. The NRC stated that selective use of the test data or methods from the EPRI program may result in under predicting the thrust or torque required to operate gate, globe, or butterfly valves. The NRC concluded that the EPRI PPM provides a bounding estimate of gate valve thrust requirements within the scope of the EPRI program when the conditions and limitations of the methodology are applied in their entiret At OC, the licensee attempted to justify a quantitative estimate of the conservativism of the EPRI model by using the combined results of the EPRI performance prediction progra > | |||
EPHI developed the PPM based on first principles with a limited number of valves tested to validate the overall model predictions. A reliable estimate of the amount of conservativism in the PPM would require extensive test data from a wide range of valves representing various operating conditions and service histories with respect to the valves at OC. The | |||
. licensee then would need to present the PPM to the NRC for review of the method of estimating the model's conservativism. NRC concerns with the reliability of quantitative estimates of PPM conservativism were discussed with licensee personnel during the GL 89-10 program close-out inspection at GPUN's Three Mile Island Unit 1 nuclear power L . plant in May 1997 (see NRC Inspection Report 50-289/97-07). At OC,' the licensee will need to justify further its PPM thrust uncertainty approach if used to evaluate MOV operabilit c.- Conclusion in evaluating the operability of containment spray valves V-21-5 and V-21-11, GPUN used an inadequately validated method to reduce the conservativisms built into the EPRI motor- | |||
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l - operated valve thrust performance prediction model. As discussed in Section E1.1, the licensee was able to demonstrate operability of these MOVs by other mean E7 Quality Assurance in Engineering Activities E Motor-Operated Valve Proaram Self-Assessment Insoection Scope in response to NRC findings identified during a June 1996 inspection of the Three Mile Island Unit 1 (TMI) Generic Letter 89-10 program (see NRC Inspection Report 50-289/96-05), the licensee conducted a self-assessment of the programs at TMI and OC. The inspectors reviewed GPUN document No. 6700-961101," Oyster Creek Generic Letter 89-10 Motor-Operated Valve Program - Report of the independent Review Team," dated November 26,1996. | |||
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bL Observations and Findinas The self-assessment team was led by the GPUN Director of Licensing and Regulatory | |||
. Affairs, and included industry experts in MOV engineering, including EPRI. The | |||
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assessment included a detailed review of the attributes of successful MOV programs throughout the country. The major. technical and programmatic findings included: | |||
* Descriptions.and justifications of methods used to demonstrate MOV capability were weak in certain respects | |||
* Program activities did not employ GPUN design and document control administrative processes | |||
* Strengths in team culture and individual performance mitigated the administrative weaknesses The team attributed the program deficiencies to limited site-specific test data, and schedule pressure. Thirteen technical and four administrative recommendations were made to correct the self-assessment finding The licensee conducted a thorough and self-critical self-assessment that confirmed many of the NRC's technical findings. The inspectors confirmed that the self-assessment recommendations were captured and tracked by Licensing Action Requests, that many of the technical weaknesses had been corrected, and that most of the remaining items were scheduled for completion during the Fall 1998 refueling outag l | |||
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I Conclusions j GPUN conducted a thorough and self-critical assessment of the Oyster Creek GL 8910 | |||
>. MOV program. Deficiencies identified by the self-assessment team were addressed | |||
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adequately. | |||
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E8 Miscellaneous Engineering issues E (Closed) VIO E97-421/ item 02013: Operability of reactor water cleanuo system valve V-16-2 | |||
~ This normally closed valve originally was designed to supply system flow when reactor vessel pressure was less than 125 psig. However, the licensee used the valve during normal power operation to fill and vent the system following maintenance or surveillance testing. The design-basis thrust calculation for the valve erroneously assumed that I upstream isolation valve V-16-1 would be closed whenever valve V-16-2 was open, ! | |||
resulting in no differential pressure across the valve. Thus the valve was not capable of | |||
" closing against a postulated high energy line break differential pressure of 1020 psig. The o licensee documented the condition in Licensee Event Report (LER) 50 219/97-004, .. | |||
" Reactor Water Cleanup Valve May Not Operate During a Line Break Due to Personnel Error."- | |||
' Current valve operability is based on the results of thrust calculation C-1302 215-E310-056, "V-16-2 Thrust & Operator Sizing for HELB Evaluation." The licensee assumed a valve factor of 0.88, based on the highest valve factor documented in industry blowdown tests of similar valves. The MOV currently does not have design-basis capability of closin , | |||
if bounding design assumptions regarding rate of loading, stem friction coefficient, and packing load are considered. However, the inspectors verified current MOV operability using the actual measured packing load and stem friction coefficient.' GPUN committed to modify the valve internals and complete a design basis thrust calculation using the EPRI PPM during the upcoming Fall 1998 refueling outage, l The licensee completed the additional corrective actions that were outlined in LER 97-004, including: (1) revising GL 89-10 affected differential pressure calculations; (2) performing a detailed review of GL'89-10 valve differential pressure condition; (3) revising the Oyster l Creek GL 89-10, Supplement 3, response to include valve V-16-2 as a high energy l | |||
- blowdown valve; and (4) informing all engineers of the event and the importance of design l-- ; | |||
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verification through required reading of the LE The inspectors concluded that the licensee's commitment and corrective actions were acceptabl ! | |||
E8.2 Review of Uocated Final Safety Analysis Report Discovery of a licen'see operating its facility in a manner contrary to the Updated Final Safety Analysis Report (UFSAR) description highlighted the need for a special focused 3 | |||
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' review that compares plant practices, procedures, and/or parameters to the UFSAR l l' < | |||
descriptions. While performing the inspections discussed in this report, the inspectors ! | |||
reviewed Oyster Creek UFSAR Sections 6.2 (Containment Systems) and 6.3 (Emergency l L ' Core Cooling Systems). The inspectors verified that the wording in the UFSAR was I consistent with the observed plant practices, procedures, and parameter l | |||
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X1 Exit Meeting Summary ; | |||
l GPUN representatives were informed of the purpose and scope of the inspection at an entrance meeting conducted on June 15,1998. Findings were discussed periodically with the licensee throughout the course of the inspection. The inspectors met with the principals listed below on June 19,1998, at which time a final exit meeting was conducted to summarize the preliminary inspection findings. The licensee acknowledged the preliminary inspection findings and conclusions, with no exceptions taken. The bases | |||
' for the inspection conclusions did not involve proprietary information, nor was any such .; | |||
information included in this inspection repor ; | |||
PARTIAL LIST OF PERSONS CONTACTED GPU Nuclear incorporated M. Roche .Vice-President and Director, Oyster Creek S. Levin Director, Operations and Maintenance W. Behrle Manager, GPUN Programs i D. Distel GPUN Licensing and Regulatory Affairs ! | |||
. S. Tiwari | |||
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Lead Assessor, Nuclear Safety Assessments J.Tabone Engineer, Mechanical & Structural T. Quintenz Engineer, Mechanical & Structural U.S. Nuclear Reaulatorv Commission | |||
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J.Schoppy Senior Resident inspector i INSPECTION PROCEDURES USED l Tl 2515/109 Inspection Requirements for Generic Letter 89-10, " Safety-Related - | |||
Motor-Operated Valve Testing and Surveillance" l | |||
ITEMS OPENED, CLOSED, AND DISCUSSED Closed ! | |||
E97-421/ item 02013 eel _ Reactor Water Cleanup Valve V-16-2 Operability LIST OF ACRONYMS USED BWRO Boiling Water Reactor Owners Grou #. | |||
.CFR Code of Federal Regulations E . Emergency condenser ! | |||
EPRI Electric Power Research Institute GL . Generic Letter ] | |||
GPUN GPU Nuclear incorporated | |||
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HELB High energy line break LAR Licensing Action Request I | |||
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Ibf pounds-force LER Licensee Event Report MOV(s) Motor-operated valve (s) | |||
PPM Performance Prediction Methodology psig pounds per square inch - gage RWCU Reactor water' cleanup-UFSAR Updated Final Safety Analysis Report OYSTER CREEK MOV PROGRAM DOCUMENTS REVIEWED Calculations C-1302-730-5350-004," Generic Letter 89-10 Program - AC MOVs - Degraded Grid Calculation," Revision 6, dated May 29,1996 , | |||
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C-1302-900-E540-015," Motor Operated Valve (MOV) Unwedging Load, GL 89-10," | |||
Revision 0, dated December 23,1997 1 i | |||
. C-1302-900-E540-013,"MOV Delta P and Basis, GL 89-10," Revision 0, dated December 12,1997 | |||
.C-1302 241-5310-056," Thrust & Operator Sizing, V21-5," Revision 2, dated March 3, 1998 l | |||
C-1302-900-E540-016," PPM Thrust Calculation For GL 89-10 Gate Valves," Revision 0, l dated December 31',1997 C-1302-215-5310-026," Thrust & Operator Sizing, V-16-1," Revision 7, dated December 24,1997 C-1302-215-E310-056,"V 16-2 Thrust & Operator Sizing for HELB Evaluation," Revision l 0, dated July 24,1997 l | |||
C-1302-211-5310-061," Thrust & Operator Sizing, V-14-30," Revision 8, dated March 12, ' | |||
1998 | |||
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C 1302-2115310-067," Thrust & Operator Sizing, V-14-36," Revision 6, dated December 31,1998 | |||
: C-1302 212-5310-072," Thrust & Operator Sizing, V-20-25," Revision 1, dated September | |||
'27,1994 C 1302-212 5310-079," Thrust & Operator Sizing, V-20-40," Revision 1, dated September 27,1994 C-1302-241-5310-059," Thrust & Operator Sizing, V-21-15," Revision 1, dated February 28,1995 | |||
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C-1302-241-5310-061," Thrust & Operator Sizing, V 21-18," Revision 1, dated February 17,1995 C-1302-214-5310-023," Thrust & Operator Sizing, V-17-19, Revision 1, dated September 26,1994 C-1302-214-5310-024," Thrust & Operator Sizing, V-17-54," Revision 1, dated September 24,1994 | |||
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C-1302-241-E310-083," Valves V-21-5 and V-21-11 Operability Calculation for PPM," | |||
Revision 0, dated January 7,1998 Modification Packaqqa OC-MD-F383-001,"89-10,17R Cable and Conduit Modification," Revision 0, dated j February 13,1998 ' | |||
OC-CCD-403079-001,"M-G Set Charger B Auto Start and 125 VDC Buses B and C | |||
- Voltmeter Replacement and Alarm Modification," Revision 1, dated March 7,1998 Technical Pacers i Topical Report 112, " Stem Factor / Rate of Loading for TMI 1 Generic Letter 89-10 Gate & | |||
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Globe Valves, Revision 0, dated February 13,1997 Engineering Evaluation 125.1 No. 230-97," Generic Letter 89-10 MOV Stem Factor and Rate of Loading," Revision 18, dated December 11,1997 Engineering Evaluation 125.1 No. 0235-97," Gate Valve Factors By Grouping," Revision 19, dated March 11,1998 Document No. 6700-96-1101," Oyster Creek Generic Letter 89-10 Mcaor-Operated Valve Program - Report of the Independent Review Team,". dated November 26,1996 | |||
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}} | }} |
Latest revision as of 11:02, 17 December 2021
ML20236L847 | |
Person / Time | |
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Site: | Oyster Creek |
Issue date: | 07/02/1998 |
From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
To: | |
Shared Package | |
ML20236L831 | List: |
References | |
50-219-98-07, 50-219-98-7, GL-89-10, NUDOCS 9807130203 | |
Download: ML20236L847 (13) | |
Text
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U. S. NUCLEAR REGULATORY COMMISSION
REGION I
Report No: 98-07 Docket No: 50-219 License N DPR 16 Licensee: GPU Nuclear incorporated 1 Upper Pond Road Parsippany, New Jersey 07054 Facility Name: Oyster Creek Nuclear Generating Station
- Location: Forked River, New Jersey inspection Period: June 15 - 19,1998 Inspector: Douglas Dempsey, DRS Participating Personnel: Thomas Scarbrough, NRR/EMEB Approved By: Eugene M. Kelly, Chief Systems Engineering Branch Division of Reactor Safety l
9807130203 900702 PDR ADOCK 05000219 G PDR ,
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EXECUTIVE SUMMARY Oyster Creek Nuclear Generating Station Report No. 50-219/98-07 This inspection reviewed the status of the Oyster Creek motor-operated valve (MOV) ;
program to determine its acceptability for closure of the NRC's review under Generic Letter q
(GL) 8910, " Safety-Related Motor-Operated Valve Testing and Surveillance." Progress .
has been made, and the quality of calculations and supporting technical evaluations in the program were good. However, the NRC was unable to reach closure regarding the review due to the large proportion of MOVs in the program for which modifications and updated calculations remain to be complete * Although action plans were tracked and scheduled, the licensee had not yet adequately verified the design basis capability of approximately two-thirds of the valves in its GL 89-10 program. This included all of the twelve risk-significant high energy line break isolation valves at Oyster Creek. However, the inspectors found i current MOV functionality to be acceptable, based on independent evaluation of industry data. GPUN performed acceptable technical evaluations of load sensitive behavior, stem friction coefficient, and dynamic unwedging thrust requirement (Section E1.1)
- In evaluating the operability of containment spray valves V-21-5 and V-21-11, GPUN used an inadequately validated method to reduce perceived conservativisms in the Electric Power Research Institute MOV Performance Prediction Methodolog ,
However, the licensee adequately justified current MOV functionality by other means. (Section E1.2)
- GPUN conducted a thorough and self-critical assessment of the Oyster Creek GL 8910 MOV program. Deficiencies identified by the self-assessment team were addressed adequately. (Section E7.1)
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Report Details 111. Enaineerina j E1 Motor-Operated Valve Program Review (Tl 2515/109)
. E Justification of MOV Prooram Assumptions Insoection Scope
- On June 28,1989, the NRC issued Generic Letter (GL) 89-10, " Safety-Related Motor- ;
Operated Valve Testing and Surveillance," which requested licensees to establish a
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program to ensure that switch settings for safety-related motor-operated valves (MOVs)
were selected, set, and maintained properly. Seven supplements to the GL have been issued to provide additionalinformation and guidance on development of program . Previous inspections at the Oyster Creek Nuclear Generating Station were conducted based on guidance contained in NRC Temporary Instruction (TI) 2515/109," Inspection Requirements for Generic Letter 89-10."
The purpose of this inspection was to examine the actions implemented at Oyster Creek (OC) and to determine if those actions were sufficient to warrant closure of the NRC staff review of the GL 89-10 MOV program. The inspection was focused primarily on risk-
- significant high energy isolation valves in the reactor water cleanup and emergency condenser systems. The engineering evaluations, topical reports, modification packages, and calculations reviewed during the inspection are listed at the end of this inspection l report. The inspectors verified current valve operability by performing independent calculations of thrust requirements and motor-actuator capabilities, Observations and Findinas Overall Proaram Status There are'27. valves in the GL 8910 program at Oyster Creek. The licensee (GPUN) had !
not completed all of its planned actions to demonstrate design basis capability for two l thirds (18) of the valves in the program. Nine valves in the reactor building closed cooling water, shutdown cooling, and containment (torus) cooling systems fully satisfied design basis thrust requirements based on dynamic tests and a grouping method that was consistent with the recommendations in Supplement 6 of GL 89-10 for sample siz . Thrust calculations using the Electric Power Research Institute (EPRI) MOV Performance Prediction Methodology (PPM) were completed for eight valves in the emergency
. condenser (EC) and containment (drywell) spray systems.' Draft PPM calculations for the four high energy line break containment isolation valves in the reactor water cleanup (RWCU) system were in the design review process at the time of the inspection, and were
- scheduled for completion in time to support valve internals modifications during the upcoming (Fall 1998) refueling outage. PPM calculations for the remaining six emergency condenser and core spray system valves also were in draft form. The licensee has scheduled the latter valves for completion during the year 2000 refueling outage. GPUN
. also committed to complete its structural (weak link) and stroke time calculations by the
. end of the 1998 refueling outage.
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- Valve Factor
+ in inspection. Report 50 219/97-05,the NRC concluded that GPUN had not justified its j
' valve factor assumptions for contestable valves adequately. In response to the NRC's {
findings and the results of a subsequent MOV program self assessment, the licensee implemented or planned corrective actions for the valve groups discussed below. The inspectors verified that each item is being tracked by a Licensing Action Request (LAR).
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- -Group 1 A consisted of three, six-inch,600 psi, Anchor-Darling flexible wedge gate valves in the RWCU system. The valves are required to close under blowdown
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conditions to' terminate a high energy line break as discussed in Supplement 3 of
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GL' 89-10. Originally, the licensee assumed a valve factor of 0.59 based on tests l performed by EPRI and other utilities. However, all but one of the 32 tests cited by (-. - the licensee were performed under pumped flow (rather than blowdewn) conditions, l and the information from two industry blowdown tests of Anchor-Darling valves 1
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. was not included in the data set. These two valves exhibited unpredictable L- behavior and suffered significant internal damag GPUN int' ends to modify the valve internals to meet PPM guidelines and to perform l PPM thrust calculations for the valves by the Fall 1998 (17R) refueling outage. In the interim, the inspectors considered the current valve actuator setups to be ]
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acceptable. With the torque switches bypassed and degraded voltage motor
- capability calculations that properly included elevated temperature effects, rate of loading, pullout efficiency, and a 0.9 application factor, the MOVs were capable of overcoming a 0.76 valve factor.
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- - Group 1B consisted of six, eight-inch,600 psi, Anchor Darling flexible wedge gate
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valves in the core spray system. The licensee plans to remove two of the valves
' (V-20-12 and V-20-18) from the program on the basis of declaring the core spray system inoperable when the valves are closed for testing or maintenance. The basis for exclusion was consistent with GL 8910 guidance and acceptabl Per Engineering Evaluation.125.1 (File # 0235-97)," Gate Valve Factor By Grouping," the licensee assumed a valve factor of 0.7 for this group. GPUN also
= previously had agreed to maintain an available thrust margin of at least 18,000 pounds-force (lbf) above running load. The valve factor assumption was based on the highest valve factor observed during tests of similar valves at another plan However, since the licensee did not perform a rigorous engineering review of these tests, the inspectors considered the assumption to be acceptable only for interim operability. Based on the current torque switch settings and measured running loads, and accounting for rate of loading and diagnostic uncertainties, the MOVs are
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capable of overcoming a valve factor of approximately on * Group 1C consisted of two,10-inch,600 psi, Anchor-Darling flexible wedge gate
. valves in the EC condensate return lines., GPUN plans to modify the valve internals
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'and to perform PPM calculations by the year 2000 (18R) refueling outage. The deferral was unavoidable because the valve work requires a full core off-load to the i
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spent fuel pool, which cannot be performed during the 17R refueling outage, in the interim, the MOVs are capable of overcoming a valve factor of 0.79 assuming the running loads and stem friction coefficients measured during the latest static i diagnostic tests. In addition, during the upcoming 17R refueling outage, the licensee plans to implement modification OC-MD-F383-001,"89-10,17R Cable &
Conduit Modification," to increase the thrust margin of valve V-14-36 under degraded grid condition * Groups 2A and 2B consisted six,10-inch,900 psi, Anchor-Darling double-disk gate valves in the EC system. The licens0e performed EPRI PPM hand calculations to define the design basis thrust requirements for these high energy line break isolation valves. During a previous refueling outage, the licensee verified that the valve disks were oriented in the preferred direction in order to support the PPM calculation conclusions. GPUN plans to increase the design capability of valve V-14-30 (which had a design margin of only six percent) by replacing the motor power cable during'
the.17R refueling outage. Pending implementation of the cable modification, the inspectors considered the MOVs in these groups to be acceptable for GL 89-10 !
program closur * Group 3A contained two,14-inch,150 psi, Ohio injector Company solid wedge gate valves in the drywell spray system. In its thrust calculations using the - ,
standard industry equation, the licensee used a valve factor of 0.6, based on l comparison with 12",150 psi, Anchor Darling valves. Subsequent review l confirmed that there were no significant differences between the valves. The licensee completed PPM calculations in late 1997. Since the disk and seat ring faces were not fabricated with PPM-validated materials (monel alloy 505 and satellite 7 versus satellite 6), the calculation's results are considered to be best available information, subject to long term validation through a test program. A O.62 valve factor was back-calculated from the PPM result As currently set up, the thrust capabilities of valves V-21-5 and V-21-11 were marginal. To demonstrate interim operability until the Fall 1998 refueling outage, the licensee used a statistical analysis to remove some of the perceived .
" conservatism"in the EPRI model. As discussed in Section E1.2 of this report, the
. inspectors considered the analysis to be unacceptable. However, using more standard methods based on measured (versus design basis) stem friction coefficients, packing loads, and rate of loading, the licensee was able to show that the valves were operable. GPUN plans to increase the torque switch settings for these valves during the 17R refueling outage, i
. ' C Group 4 contained two,14-inch,900 psi, Velan flexible wedge gate valves in the shutdown cooling system.' Per Engineering evaluation 125.1 (File # O235-97), a valve factor of 0.8 was assumed based on a single in-situ dynamic test performed at 80% of design differential pressure (measured valve factor was 0.66), and industry tests of similar valves. The licensee did not perform a rigorous engineering review of the industry tests, and the inspectors did not consider the data to be adequate for design purpose .
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The thrust capability margin of valve V-17-19 was acceptable (approximately 17%).
l However, the current torque switch setting of valve V-17-54 was not adequate to meet the design basis valve factor assumption of 0.8; using measured (versus
' design basis) values of rate of loading and packing load in the standard industry i equations, the available valve factor was 0.78 for this MOV. However, the MOV was capable using the tested valve factor of 0.66. During the 17R refueling outage, the licensee plans to bolster its valve factor assumption by dynamically testing both valve ,
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- . Group 6 consisted of two, four-inch,150 psi, Velan flexible wedge gate valves in the containment (torus) spray system. The licensee's 1997 self-assessment team j concluded that the assumed valve factor of 0.6 was not supported adequately b l the results of in-situ dynamic tests and industry data. The inspectors found that the i i valva Mpability margins were very low at the current torque switch settings if design basis rate of loading and packing load assumptions were used. However, _;
using measured packing loads, an immediate operability concern does not exist with l the current torque switch settings. GPUN plans to dynamically test both valves '
during the 17R refueling outage to validate its valve' factor assumptio !
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l In summary, GPUN committed to perform the following actions during the Fall 1998 -]
refueling outage: (1) modify valve internals and complete PPM thrust calculations for three
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, RWCU system valves in Group 1 A; (2) adjust the torque switch settings for two drywell I spray system valves in Group 3A; (3) replace power cables for EC system valves V-14-30 l and V-14-36; and (4) and dynamically test four valves in the drywell spray and shutdown i cooling systems (Groups 6 and 4, respectively). GPUN also committed to modify valve internals and complete PPM thrust calculations for two EC system valves (Group 1C) and l to complete PPM calculations for 4 core spray system valves (Group 1B) during the year
- 2000 refueling outage. The inspectors noted that the licensee's consideration of the limitations and conditions identified in the NRC safety evaluation of the EPRI PPM was not clear in all instance I Stem Friction Coefficient and Load Sensitive Behavior In NRC inspection Report 50-219/97-05,the NRC concluded that the GPUN's treatment of load sensitive behavior (aka " rate of loading") was not well supported by a statistically
! significant amount of test data. In its August 5,1997 letter to the NRC, the licensee
!: discussed a plan to obtain the necessary information from the EPRI PPM, and committed to I' incorporate the EPRI rate of loading methodology into its torque switch settings by the end of 1997, and to apply the methodology to its stroke time calculations by the end of the Fall 1998 refueling outage. In a letter to the NRC dated February 3,1998, GPUN indicated
- that the justification for its rate of loading and stem lubricant degradation assumptions had ,
been completed.-
The licensee described its justification for the stem friction coefficient and rate of loading assumptions in Engineering Evaluation 125.1 (File # 230-97)," Generic Letter 89-10 MOV Stem Factor and Rate of Loading," dated December 11,1997. Where possible, actual stem friction coefficients of less than 0.15 were verified during static diagnostic tests. To
' account for the effect of !oad sensitive behavior, the licensee typically adds 0.046 to the b
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measured static stem friction coefficient to estimate the coefficient that might result under dynamic conditions. If no valve-specific test data exists, the evaluation indicated that e O.-2 dynamic stem friction coefficient would be assumed, except in certain instances. In determining the minimum required static thrust set point, GPUN assumed a 5.3% leas and 19% random value for rate of loading based on its review of Oyster Creek, EPRI, and Boiling Water Reactor Owner Group (BWROG) test data. The licensee aLo assumed a 1.2% bias and 4% random value for lubricant degradation. GPUN also evaluated unwedging test data to support the absence of load sensitive behavior during this limited portion of a valve opening strok EPRI did not test the stem lubricant (Synco Chemical Company Super Lube EP 2) applied at Oyster Creek. The licensee evaluated the general differences in the Oyster Creek and EPRI stem greases to support its assumption that the lubricants will perform in a similar manner, and indicated that additional testing is planned to justify further its stem friction coefficient and rate of loading assumptions for its specific stem grease. Further, GPUN will need to continue to monitor test data to confirm its assumption of the absence of load sensitive behavior during gate valve unwedging. GPUN committed to specify its plans for obtaining additional test information to justify its stem friction coefficient and rate of loading assumptions for the stem grease used at O Unwednina Thrust Requirements in conducting its test program, EPRI determined that the thrust required to open gate valves under differential pressure conditions can exceed the thrust required to open those valves under static (zero differential pressuie) conditions. As part of the PPM, EPRI provided guidance for licensees using the methodology to estimate the thrust required to pull the discs out of the seats for wedge-type gate valves and Anchor-Darling double-disk gate valves. Unwedging thrust requirements are predicted separately from the thrust requirements to overcome dynamic flow effects obtained from the EPRI valve model In calculation C-1302-900-E54C 015," Motor Operated Valve (MOV) Unwedging Load, GL 89-10,"the licensee described its evaluation of the capability of motor actuators to unwedge the applicable MOVs in its GL 89-10 program. GPUN followed the approach outlined by EPRIin its topical report. The licensee will need to consider the effect of recently issued Limitorque Technical Update 98-01 on its prediction of motor actuator output for the evaluation of the capability of its safety-related MOVs to overcome unwedging loads (and other MOV operating requirements). Conclusions Although action plans were tracked and scheduled, the licensee had not yet adequately established the design basis capability of approximately two-thirds of the valves in its GL 89-10 program. This included all of the twelve risk-significant high energy line break isolation valves at Oyster Creek. However, the inspectors found current MOV functionality to be acceptable, based on independent evaluation of industry data. GPUN performed acceptable technical evaluations of load sensitive behavior, stem friction coefficient, and dynamic unwedging thrust requirements.
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E1.2 EPRI Performance Prediction Methodoloav Thrust Uncertainty . Insoection Scope GPUN determined that containment (drywell) spray valves V 21-5 and V-21-11 were no able to' meet the thrust requirements predicted by the EPRI PPM. The licensee documented its operability determination for the valves in calculation C-1302-241-E310-083," Valves V-21-5 and V-21-11 Operability Calculation for PPM." The inspectors reviewed the calculatio Observations and Findinas The licensee used test results from the EPRI test program and derived a value for the
. perceived conservativism in the output of the performance prediction model. GPUN then applied the derived quantitative value of "conservativism" as an uncertainty to reduce the predicted thrust requirement for valves V-21-5 and V-21-11. With the lower thrust requirement, the licensee concluded that the valves were operabl In its February 20,1997 Supplement to the Safety Evaluation (SE) on the EPRI PPM, the NRC stated that it had reviewed the EPRI methodology as a complete package in that cortain nonconservative assumptions in the models are compensated by other conservative assumptions in the analytical formulas. The NRC stated that selective use of the test data or methods from the EPRI program may result in under predicting the thrust or torque required to operate gate, globe, or butterfly valves. The NRC concluded that the EPRI PPM provides a bounding estimate of gate valve thrust requirements within the scope of the EPRI program when the conditions and limitations of the methodology are applied in their entiret At OC, the licensee attempted to justify a quantitative estimate of the conservativism of the EPRI model by using the combined results of the EPRI performance prediction progra >
EPHI developed the PPM based on first principles with a limited number of valves tested to validate the overall model predictions. A reliable estimate of the amount of conservativism in the PPM would require extensive test data from a wide range of valves representing various operating conditions and service histories with respect to the valves at OC. The
. licensee then would need to present the PPM to the NRC for review of the method of estimating the model's conservativism. NRC concerns with the reliability of quantitative estimates of PPM conservativism were discussed with licensee personnel during the GL 89-10 program close-out inspection at GPUN's Three Mile Island Unit 1 nuclear power L . plant in May 1997 (see NRC Inspection Report 50-289/97-07). At OC,' the licensee will need to justify further its PPM thrust uncertainty approach if used to evaluate MOV operabilit c.- Conclusion in evaluating the operability of containment spray valves V-21-5 and V-21-11, GPUN used an inadequately validated method to reduce the conservativisms built into the EPRI motor-
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l - operated valve thrust performance prediction model. As discussed in Section E1.1, the licensee was able to demonstrate operability of these MOVs by other mean E7 Quality Assurance in Engineering Activities E Motor-Operated Valve Proaram Self-Assessment Insoection Scope in response to NRC findings identified during a June 1996 inspection of the Three Mile Island Unit 1 (TMI) Generic Letter 89-10 program (see NRC Inspection Report 50-289/96-05), the licensee conducted a self-assessment of the programs at TMI and OC. The inspectors reviewed GPUN document No. 6700-961101," Oyster Creek Generic Letter 89-10 Motor-Operated Valve Program - Report of the independent Review Team," dated November 26,1996.
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bL Observations and Findinas The self-assessment team was led by the GPUN Director of Licensing and Regulatory
. Affairs, and included industry experts in MOV engineering, including EPRI. The
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assessment included a detailed review of the attributes of successful MOV programs throughout the country. The major. technical and programmatic findings included:
- Descriptions.and justifications of methods used to demonstrate MOV capability were weak in certain respects
- Program activities did not employ GPUN design and document control administrative processes
- Strengths in team culture and individual performance mitigated the administrative weaknesses The team attributed the program deficiencies to limited site-specific test data, and schedule pressure. Thirteen technical and four administrative recommendations were made to correct the self-assessment finding The licensee conducted a thorough and self-critical self-assessment that confirmed many of the NRC's technical findings. The inspectors confirmed that the self-assessment recommendations were captured and tracked by Licensing Action Requests, that many of the technical weaknesses had been corrected, and that most of the remaining items were scheduled for completion during the Fall 1998 refueling outag l
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I Conclusions j GPUN conducted a thorough and self-critical assessment of the Oyster Creek GL 8910
>. MOV program. Deficiencies identified by the self-assessment team were addressed
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adequately.
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E8 Miscellaneous Engineering issues E (Closed) VIO E97-421/ item 02013: Operability of reactor water cleanuo system valve V-16-2
~ This normally closed valve originally was designed to supply system flow when reactor vessel pressure was less than 125 psig. However, the licensee used the valve during normal power operation to fill and vent the system following maintenance or surveillance testing. The design-basis thrust calculation for the valve erroneously assumed that I upstream isolation valve V-16-1 would be closed whenever valve V-16-2 was open, !
resulting in no differential pressure across the valve. Thus the valve was not capable of
" closing against a postulated high energy line break differential pressure of 1020 psig. The o licensee documented the condition in Licensee Event Report (LER) 50 219/97-004, ..
" Reactor Water Cleanup Valve May Not Operate During a Line Break Due to Personnel Error."-
' Current valve operability is based on the results of thrust calculation C-1302 215-E310-056, "V-16-2 Thrust & Operator Sizing for HELB Evaluation." The licensee assumed a valve factor of 0.88, based on the highest valve factor documented in industry blowdown tests of similar valves. The MOV currently does not have design-basis capability of closin ,
if bounding design assumptions regarding rate of loading, stem friction coefficient, and packing load are considered. However, the inspectors verified current MOV operability using the actual measured packing load and stem friction coefficient.' GPUN committed to modify the valve internals and complete a design basis thrust calculation using the EPRI PPM during the upcoming Fall 1998 refueling outage, l The licensee completed the additional corrective actions that were outlined in LER 97-004, including: (1) revising GL 89-10 affected differential pressure calculations; (2) performing a detailed review of GL'89-10 valve differential pressure condition; (3) revising the Oyster l Creek GL 89-10, Supplement 3, response to include valve V-16-2 as a high energy l
- blowdown valve; and (4) informing all engineers of the event and the importance of design l-- ;
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verification through required reading of the LE The inspectors concluded that the licensee's commitment and corrective actions were acceptabl !
E8.2 Review of Uocated Final Safety Analysis Report Discovery of a licen'see operating its facility in a manner contrary to the Updated Final Safety Analysis Report (UFSAR) description highlighted the need for a special focused 3
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' review that compares plant practices, procedures, and/or parameters to the UFSAR l l' <
descriptions. While performing the inspections discussed in this report, the inspectors !
reviewed Oyster Creek UFSAR Sections 6.2 (Containment Systems) and 6.3 (Emergency l L ' Core Cooling Systems). The inspectors verified that the wording in the UFSAR was I consistent with the observed plant practices, procedures, and parameter l
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X1 Exit Meeting Summary ;
l GPUN representatives were informed of the purpose and scope of the inspection at an entrance meeting conducted on June 15,1998. Findings were discussed periodically with the licensee throughout the course of the inspection. The inspectors met with the principals listed below on June 19,1998, at which time a final exit meeting was conducted to summarize the preliminary inspection findings. The licensee acknowledged the preliminary inspection findings and conclusions, with no exceptions taken. The bases
' for the inspection conclusions did not involve proprietary information, nor was any such .;
information included in this inspection repor ;
PARTIAL LIST OF PERSONS CONTACTED GPU Nuclear incorporated M. Roche .Vice-President and Director, Oyster Creek S. Levin Director, Operations and Maintenance W. Behrle Manager, GPUN Programs i D. Distel GPUN Licensing and Regulatory Affairs !
. S. Tiwari
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Lead Assessor, Nuclear Safety Assessments J.Tabone Engineer, Mechanical & Structural T. Quintenz Engineer, Mechanical & Structural U.S. Nuclear Reaulatorv Commission
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J.Schoppy Senior Resident inspector i INSPECTION PROCEDURES USED l Tl 2515/109 Inspection Requirements for Generic Letter 89-10, " Safety-Related -
Motor-Operated Valve Testing and Surveillance" l
ITEMS OPENED, CLOSED, AND DISCUSSED Closed !
E97-421/ item 02013 eel _ Reactor Water Cleanup Valve V-16-2 Operability LIST OF ACRONYMS USED BWRO Boiling Water Reactor Owners Grou #.
.CFR Code of Federal Regulations E . Emergency condenser !
EPRI Electric Power Research Institute GL . Generic Letter ]
GPUN GPU Nuclear incorporated
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HELB High energy line break LAR Licensing Action Request I
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Ibf pounds-force LER Licensee Event Report MOV(s) Motor-operated valve (s)
PPM Performance Prediction Methodology psig pounds per square inch - gage RWCU Reactor water' cleanup-UFSAR Updated Final Safety Analysis Report OYSTER CREEK MOV PROGRAM DOCUMENTS REVIEWED Calculations C-1302-730-5350-004," Generic Letter 89-10 Program - AC MOVs - Degraded Grid Calculation," Revision 6, dated May 29,1996 ,
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C-1302-900-E540-015," Motor Operated Valve (MOV) Unwedging Load, GL 89-10,"
Revision 0, dated December 23,1997 1 i
. C-1302-900-E540-013,"MOV Delta P and Basis, GL 89-10," Revision 0, dated December 12,1997
.C-1302 241-5310-056," Thrust & Operator Sizing, V21-5," Revision 2, dated March 3, 1998 l
C-1302-900-E540-016," PPM Thrust Calculation For GL 89-10 Gate Valves," Revision 0, l dated December 31',1997 C-1302-215-5310-026," Thrust & Operator Sizing, V-16-1," Revision 7, dated December 24,1997 C-1302-215-E310-056,"V 16-2 Thrust & Operator Sizing for HELB Evaluation," Revision l 0, dated July 24,1997 l
C-1302-211-5310-061," Thrust & Operator Sizing, V-14-30," Revision 8, dated March 12, '
1998
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C 1302-2115310-067," Thrust & Operator Sizing, V-14-36," Revision 6, dated December 31,1998
- C-1302 212-5310-072," Thrust & Operator Sizing, V-20-25," Revision 1, dated September
'27,1994 C 1302-212 5310-079," Thrust & Operator Sizing, V-20-40," Revision 1, dated September 27,1994 C-1302-241-5310-059," Thrust & Operator Sizing, V-21-15," Revision 1, dated February 28,1995
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C-1302-241-5310-061," Thrust & Operator Sizing, V 21-18," Revision 1, dated February 17,1995 C-1302-214-5310-023," Thrust & Operator Sizing, V-17-19, Revision 1, dated September 26,1994 C-1302-214-5310-024," Thrust & Operator Sizing, V-17-54," Revision 1, dated September 24,1994
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C-1302-241-E310-083," Valves V-21-5 and V-21-11 Operability Calculation for PPM,"
Revision 0, dated January 7,1998 Modification Packaqqa OC-MD-F383-001,"89-10,17R Cable and Conduit Modification," Revision 0, dated j February 13,1998 '
OC-CCD-403079-001,"M-G Set Charger B Auto Start and 125 VDC Buses B and C
- Voltmeter Replacement and Alarm Modification," Revision 1, dated March 7,1998 Technical Pacers i Topical Report 112, " Stem Factor / Rate of Loading for TMI 1 Generic Letter 89-10 Gate &
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Globe Valves, Revision 0, dated February 13,1997 Engineering Evaluation 125.1 No. 230-97," Generic Letter 89-10 MOV Stem Factor and Rate of Loading," Revision 18, dated December 11,1997 Engineering Evaluation 125.1 No. 0235-97," Gate Valve Factors By Grouping," Revision 19, dated March 11,1998 Document No. 6700-96-1101," Oyster Creek Generic Letter 89-10 Mcaor-Operated Valve Program - Report of the Independent Review Team,". dated November 26,1996
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