IR 05000280/1988012
| ML18152A914 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 05/13/1988 |
| From: | Blake J, Economos N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18152A913 | List: |
| References | |
| 50-280-88-12, 50-281-88-12, NUDOCS 8806060174 | |
| Download: ML18152A914 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, ATLANTA, GEORGIA 30323 Report Nos.:
50-280/88-12 and 50-281/88-12 Licensee:
Virginia Electric and Power Company Richmond, VA 23261 Docket Nos.:
50-280 and 50-281 Facility Name:
Surry 1 and 2 Approved Safety SUMMARY License Nos.: DPR-32 and DPR-37 Scope:
This routine, unannounced inspection was in the area of maintenance and included a review of work requests on control room and relay room chillers, auxiliary feedwater Motor Operated Valve (MOV) 2-FW-MOV-251A-F and diesel driven fire pum Results:
No violations or deviations were identified.
8806060174 880519 PDR ADOCK 05000280 Q
,.
- Persons Contacted Licensee Employees REPORT DETAILS
- D. L. Benson, Station Manager
- G. D. Miller, Licensing Coordinator R. C. Boles Jr., Systems Engineer E. Brennan~ Supervisor Mechanical Maintenance J. E. Epperson, Maintenenace Services Supervisor A. McNeils, Supervisors Inservice Inspection (ISI) and Testing J. W. Ogren, Superindent Maintenance
- J. A. Price, Quality Assurance Manager G. Thompson, Maintenance Engineer Other licensee employees contacted included construction craftsmen, engineers, technicians, mechanics, security force members, and office personnel.
NRC Resident Inspectors
- L. Nicholson, Resident Inspector
- Attended exit interview Exit Interview The inspection scope and findings were summarized on April 15, 1988, with those persons indicated in Paragraph 1 abov The inspector described the areas inspected and discussed in detail the inspection finding No dissenting comments were received from the license The following new item was identified during this inspectio (Open) Unresolved Item (UNR) 50-280,281/88-12-0l, Engineering Evaluation and Report of Control/Relay Room Chillers, The licensee did not identify as proprietary any of the materials provided to or reviewed by the inspector during this insp~ctio.
Licensee Action on Previous Enforcement Matters Units 1 and 2 This subject was not addressed in the inspectio.
Unresolved Items Unresolved items are matters about which more information is required to determine whether they are acceptable or may involve violations or
deviations. *one unresolved item identified during this inspection is discussed in Paragraph.
Maintenance Program Implementation (62700) Fire Protection Water Pump= Maintenance and Testing In the process of discussing current outage activities with the licensee's cognizant.engineer, the inspector ascertained that the diesel driven fire protection water pump was undergoing repairs and testin The repairs involved the removal and replace-ment of the original flywheel, per vendor recommendation, as a product improvemen The licensee received this recommendation via an information type bulletin issued by Cunmins Engine Company (Vendor)~ entitled Service Parts Topics, No. 85Tl6-1 June 198 According to this documentj the new flywheel was made from ductile iron material and therefore was stronger and lighter in weight than the original flywheel. Aside from the fact that the new flywheel was apparently stronger and lighterj it appears that the main issue was that service reports showed that original flywheels were developing cracks in the bolt circle or mounting area. This condition was found to exist on the original flywheel of the Surry pum During the initial tour through the fire pump house, on April 12, 1988, the inspector was informed that the operational pump tests following installation of the new flywheel, generated unacceptable vibration value Therefore, in an effort to alleviate this condition, the licensee reinstalled the original flywheel and retested the pump with favorable result Following the aforementioned walk through inspection, the inspector discussed operating the pump with the cracked flywheel and stated that an engineering evaluation using fracture mechanics analysis should be performed to show that the pump could be operated in a safe and reliable manner under existing condition On April 13, 1988, the inspector ascertained that the licensee in consultation with the vendor installed the new flywheel and replaced the original coupling between the diesel and the pump with a newly designed couplin The inspector observed the functional testing of subject pump and noted that the amplitude of the vibrations had diminished to the acceptable rang The observed functional test was conducted in accordance with Procedure I-PT -24.1 "Fi re Protection Water Pump".
This is a weekly test performed to assure operability and had duration of about 30 minute The parameters observed included water temperature, lube oil pressure and revolutions per minut Within these area the inspectors noted that although the Qua 1 ity Centro 1 inspector verifies that the aforementioned parameters including test duration were within the limits specified by the procedure, he does not (and, there is no requirement for him to) record the actual va 1 ues observe Therefore, there is no record for engineering
evaluations and or trending purposes et This procedural weakness was discussed with the licensee who agreed to review the procedures and take remedial action as appropriat Other documents reviewed included certificate of conformance, receipt inspection report, nondestructive examination reports and job order recor Within the area inspected no violations or deviations were identi-fie Control/Relay Room Chillers The Surry FSAR states in part that control and relay room air-conditioning is handled by independent 100% redundant air-handling units installed within the space serve One unit for each space is supplied by a separate chi 11 ed water supply, with a second supply serving the alternate unit; thus, complete redundancy is provided in case of malfunction of either a unit or its chilled water supply. Three 100% refrigeration chillers of 90 tons each serve these two groups to ensure that two are operable whenever one is down for maintenanc Condensing cooling water is provided by two independent gravity-supplied service water line Because of the unusually high number of deviation reports generated on these units during 1987, the inspector elected to review deviation reports, Licensee Event Reports (LERs) and work requests generated between January and November of 1987, * A total of thirty-eight deviation reports and associated LERs were-reviewed to ascertain whether:
The cause of the failure was evaluated and adequate corrective action was taken to reduce the probability of recurrence; the procedures specified in the maintenance package were adequate for the scope of the maintenance performed; vendor maintenance recommendati ans, if used, were correctly translated into or referenced by the maintenance procedures; and periodic surveillance testing associated with the selected failed equipment provided an indication of an impending failur Also, the aforementioned records were reviewed to ensure that:
Required administrative approval were obtained before initiating the work; limiting conditions for operation were met while the component or system was removed from service; inspections were made in accordance with the licensee's requirements, and quality
control records are complete; functional testing and calibra-ti ans, as necessary, were completed before returning the equipment to service; the licensee evaluated system failures and reported them in accordance with 10 CFR 50.73; corrective and preventive maintenance records were assembled and stored as part of the maintenance history; parts and materials used were identified and at least met the specifications of the original equipment; and special processes were controlled and documented as applicabl Within these areas the inspector made the foll ow observations:
Although the licensees FSAR commitment was to provide three, 100%
refrigeration chillers of 90 tons capacity each, the original three chillers, furnished by Westinghouse, were equipped with 80 horsepower motors thus reducing their rated capacity from 90 tons down to 6 tons eac Upon making this discovery late in 1987, the licensee evaluated the chiller package and determined that it would support system design load demand On the basis of the determination, it was decided that a report to the Commission was not require In discussing this matter, the inspector asked to see a copy of the engineering evaluation/analysis for revie In response, the licensee stated that because the evaluation showed the exciting capacity would satisfy system demand, no formal evalua-tion or 50.59 report was issue The inspector stated that he did not agree with this rationale, and indicated that the issue would be discussed further with the staff at the Region and headquarters in order to reach a consensu This matter has been identified as Unresolved Item 50-280,281/88-12-0l Engineering Evaluation and Report of Control/Relay Room Chiller Auxiliary Feedwater Motor Operated Valves On March 29, 1988 the Region issued preliminary notification, PN0-11-88-20 to document an unusual event at Surry Unit 2, because of an automatic safety injection following loss of power to a vital bu The bus provided power for containment isolation valves in the component cooling water return line from reactor coolant Pump "A".
The reactor was manually tripped and all safety systems performed as designed except for the Auxiliary Feedwater (AFW) flow to the "A" Steam Generator, (SG) which was approximately 140 gallons per minute, ( gpm) and therefore 1 ower than the expected 330 to 338 gp In order to investigate the root cause of this phenomenon, the licensee conducted extensive visual examinations of the related piping system and associated components, e.g. flow orifice, ventur Following this examination the system in question was reassembled and flow tested satisfactorily without establishing the root cause for the degraded flo This matter was under evaluation during this inspec-tio *
The AFW line in question, which supplies flow to SG "A", contains two motor operated valves, 2-FW-MOV-251E and -251 In total there are six valves, or two for each steam generator, These valves are three inch, 500 lb. carbon steel globe valves manufactured by Walwort The valves are equipped with Limitorque SMB-00 operator They (valves) are original construction equipment which were purchased to the requirements of Stone and Webster Engineering Corp. specification NUS 235~ dated February 5, 1969 and USAS B16.5 Steel Pipe Flanges and Flanged Fitting The pipe line they are installed in is designated ASME Class 2, QA Category 1, safety-related. A review of maintenance records starting with 1983 to present disclosed a continuing problem with cracking welds in the valves seats, on the disc and lock nu These failures are responsible for seat ring backing out and, valve discs and lock-nuts coming loose from the valve stem According to the manufacturer this recurring problem is related to the practice of using these valves to throttle feed flo Apparently the existing swivel disc design is not suitable for throttling application In addition Walworth suspects that thermal cycling may be a major contributing factor in these failure The thermal cycling mechanism was attributed to two factor The first, was valve seat leakage which heats up the MOVs when the AFW system is not in us The second factor was the relatively cool AFW feed which causes the rapid cooldown of the MOVs, thus generating thermal stresses which led to the cracking of these valve parts. A review of maintenance records for all six valves in Unit 2 verified the conditions described abov In addition, the inspector ascer-tained that the weld failures on the disc and lock-nut were in part due to valve misapplication, discussed earlier in this section, and the use of an improper welding procedure(s) to fabricate the tack welds to secure the lock-nu According to maintenance records, these MOVs were originally supplied with a lock-nut that was fabricated from monel type materia Subsequently, when the valves were modified to allow for throttling, the we 1 ders did not know that the 1 ock-nuts were made of mone 1 material and therefore used the wrong type of welding consumables/
procedure which caused the welds to fail early in service, Upon discovering the problem, the licensee, in consultation with Walworth, replaced the lock-nuts with others made from 410 stainless stee Reportedly, this materi a 1 has comparable strength and the therma 1 expansion characteristics are better suited for the application. All the MOVs are now equipped with lock-nuts made of 410 stainless materia According to the licensee the long term fix is to replace the present valves with others more suitable for the application. Along with the aforementioned maintenance records review, the inspector reviewed the purchase specification and procurement documents on these valve In
- response to the inspector's request for the quality records on the 410 stainless steel replacement material used by maintenance to fabricate the new lock-nuts, the licensee indicated that these were not availabl Although the inspector agreed that under ASME Section XI Article IWA=7100 these type records are not required, the inspector stressed that, in addition to good QA practices~ these type records provide valuable engineering information for material verification, failure analysis, and reference purpose The licensee agreed to look further into this matters and assure that this type of information becomes a part of the documentation packag Within the area inspected, no violations or deviations were identified.