IR 05000293/1987010

Insp Rept 50-293/87-10 on 870202-06.No Violations Noted. Major Areas Inspected:Snubber Surveillance,Previously Identified Unresolved Issues & Followup on Target Rock Safety Relief Valves W/New Stellite 21 Matl Pilot Discs

ML20204F218
Person / Time
Site:	Pilgrim
Issue date:	03/19/1987
From:	Gregg H, Strosnider J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20204F180	List: IR 05000293/1987010 ML20204F175
References
50-293-87-10, NUDOCS 8703260155
Download: ML20204F218 (7)

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U.S. NUCLEAR REGULATORY COMMISSION

REGION I

Report N /87-10 Docket N License No. OPR-35 Priority --

Category C Licensee: Boston Edison Company M/C Nuclear 800 Boylston Street Boston, Massachusetts 02199 Facility Name: Pilgrim Nuclear Power Station Inspection At: Plymouth, Massachusetts Inspection Conducted: February 2-6, 1987

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Inspectors -

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H. I. Gregg, Lead RfetIctor Engineer '

dath Approved by: ,,to J[/9I7 g.Strosnider, Chief Materials and ( dat'e '

V Processes Section Inspection Summary: Inspection on February 2-6,1987 (Report No. 50-293/87-10)

Areas Inspected: A routine unannounced inspection was conducted of licensee's activities related to snubber surveillances, previously identified unresolved issues, and followup on the Target Rock safety relief valves with new Stellite 21 material pilot disc Results: No violations were identified, however, the inspection findings identified several problem areas relating to snubber surveillances which resulted in an unresolved ite .

kDR O Ob0293 IR PILGRIM 87-10 - 0003. G PDR 03/16/87

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DETAILS 1.0 Persons Contacted 1.1 Boston Edison Company J. Accardi, Mechanical Supervisor (Quadrex Corporation)

• Clancy, Systems Group Leader

• F. Famulari, QC Group Leader J. Gadki, Senior Planning Engineer

• R. Grazio, Field Engineering Section Manager M. Greenf, Mechanical Engineer

• P. Hamilton, Senior Compliance Engineer P. Kahler, Senior Regulatory Affairs Engineer W. Riggs, Senior Mechanical Engineer

• K. Roberts, Site Manager

• R. Sherry, Chief Maintenance Engineer J. Vender, Senior Mechanical Engineer U.S. Nuclear Regulatory Commission

• J. Lyash, Resident Inspector

• T. Kim, Resident Inspector

• Denotes those present at exit meeting 2.0 Snubber Surve111ances 2.1 Visual Surveillance The inspector reviewed the licensee's visual surveillance required by Technical Specification (TS) of 79 Bergen Paterson hydraulic snubbers and 52 Pacific Scientific snubbers. The surveillance was conducted by the maintenance department and was completed on August 11, 1986 for the hydraulic snubbers and on October 1, 1986 for the mechanical snubber The surveillance identified 6 hydraulic snubbers with specific prob-lems (i.e. cylinder leak, rusty, bushing out part way, locking nut loose). A large number of hydraulic snubbers were identified as needing washers or being outside the piston cold range settin The results of the licensee's visual inspection of mechanical snub-

. bers (performed to BEC0 procedure 3.M.4-28-1) revealed one snubber with out of phase orientatio The inspector reviewed details of the licensee's testing of 6 hydrau-lic snubbers and one mechanical snubber that had visual surveillance findings. This testing was performed in accordance with TS. Based on acceptable test results these snubbers were categorized as operabl The inspector verified compliance with the TS requirements and reviewed

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the test details and determined that the licensee's position was acceptabl An engineering disposition is still required in response to Engineer-ing Service Requests (ESR)87-069 and 87-088 which identify the lic-ensee's visual surveillance finding During the review of snubber surveillances, the inspector noted that the IST group also conducted a surveillance under their program. The IST groups findings were somewhat different than the maintenance group findings. This is an indication that surveillance training and coordination may be neede .2 Functional Testing The inspector reviewed the licensee's functional testing of snubbers required by their TS paragraph 4.6.I.2. The plant has both hydraulic and mechanical snubbers and the TS requires functional testing of each typ There was one failure in the first 10% (8 snubbers) hydraulic snubber functional test sample. The snubber failed because lock up and bleed rates were outside the acceptance tolerance range. Non conformance report (NCR) 86-51 and the Engineering evaluation of the test results of this snubber (3 KIP S/N 0042-55-30-3-45) describe the details of the problem and identified the cause. In accordance with TS require-ments this failure required an additional 10% sample to be function-ally tested. To date 6 snubbers from the 2nd sample lot of 8 snub-bers have been tested and found satisfactory. (Two snubbers remain to be tested.)

The 10% mechanical snubber sample (6 snubbers) was functionally tested and found acceptable, therefore, an additional mechanical snubber functional test sample was not require The inspector made the following additional determinations:

Testing of hydraulic snubbers is done on site by licensee personnel and that each hydraulic snubber is rebuilt after as-found testin QC has oversight of the testing and rebuildin The licensee provides service information (such as length of

, time installed, temperature, radiation) to the contractor who reviews the information and upgrades the service life status of hydraulic snubbers each refueling outage Testing of mechanical snubbers is done on site by contractor personnel. Testing of mechanical snubbers is relatively new and requires special test equipment which is provided by the contracto . .

2.3 Findings 2. Visual Surveillance In review of the licensee's visual surveillance records, the inspector encountered difficulty in determining the precise problems identified during the licensee's surveillanc For example: (1) There is a notation " Rusty" but no description of what is rusty; (2) There is a notation " Lock Nut Loose" but no description to identify which lock nu The inspector's review of several NCRs written by the ISI group when they performed their ISI inspection of snubbers revealed some findings different than the maintenance department findings. For example: (1) NCR 86-114 identified a missing spherical bearing and improper cotter pin installation; (2) NCR 86-54 identified heavy gouges on piston; (3) NCR 86-84 identified snubber in contact with spring hange These observations were not identified in the maintenance department findings for inspection of the same snubber The inspector's review of the BECO procedure No. 3.M.4-28 determined that visual inspection requirements are in plac However they are general in nature, and there can be instances where interpretation must be made by the surveillance inspecto Engineering disposition of visual surveillance findings are still required as described in paragraph Each of the above issues was fully discussed with the licensee at the exit meetin . Functional Testing The inspector's review of the functional test program resulted in no unacceptable findings. Functional testing of hydrau-lic snubbers has not been completed as described in para-graph 2.2. Two snubbers remain to be tested out of the second 10% hydraulic snubber sample. For each fa' lure that may be encountered an additional 10% sample requires functional testing. The mechanical snubber testing was fully complete .4 Conclusion No violations were identified, however, the inspector did identify areas where improvements could be made in the snubber visual surveillance program. The licensee's snubber survefilance is unresolved pending completion and review of; the ESR evaluations and

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disposition of the visual surveillance findings, completion of the hydraulic snubber functional testing, evaluation of visual surveillance procedures and the need for visual surveillance training for inspection and recording of data. At the exit meeting, the site manager committed to address each of these issues by startup. (50-293/87-10-01)

3.0 Review of Previously Identified Items 3.1 (Closed) UNR 84-18-01 Provide acceptance criteria for snubber piston rod extension. The BECO Inservice Inspection Procedure No. 3.M.4-28 required the as-found piston rod extensions to be measured and record-ed. However, there were no criteria to judge acceptability and this item was unresolved pending licensee evaluation and provision of acceptance dat The licensee modified Inspection Procedure No. 3.M.4-28 to incluae a i 1/4" acceptance tolerance for the piston rod extensions. The Inspector reviewed the licensee's corrective action and determined it was acceptabl This item is close .2 (Closed) UNR 84-18-02 Requires reinspection of hangers and supports and performance of necessary corrective actions. This item was un-resolved because of the licensee's ISI findings of non conforming conditions and the subsequent change of contractors which resulted in the need to reinspect all hangers and support .

The inspector reviewed the 1983-84 ISI summary report issued in March 1985 and verified that reinspection was accomplished and all hanger identified problems were resolved. The inspector audited the records of specific hangers (SS-2-30-16, DC-10-SS-20, EA-10-SS-22, H-10-1-32 SR, H-10-1-63, PSRH-46 and PSRH-55) and determined that for each hanger the corrective action was completed. The ISI hanger records were in good order and information was readily retrievable. The in-spector also observed several supports in the plant. The supports observed were H-10-1-131 and H-10-1-65SA (supports for RHR discharge cross connection) and H-14-1-3 (Core Spray hanger).

No unacceptable conditions were identifie This item is close . 3.3 (Closed) IFI 85-20-01 Review itcensee evaluation of inadequate stem nut installed in MOV 1400-25B BECO operational testing, after an actuator change-out modification, identified a problem that prevented full open disc travel. The cause of the problem was an improperty machined stem nut, i

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The inspector reviewed the licensee's evaluation of the problem and corrective action. The license identified that Nuclear Engineering Department (NED) procedures didn't require adequate interface with the component manufacturer prior to plant modifications. Corrective action by the licensee was to revise NED procedures 3.02 and 3.07 to include interface with the component manufacture The inspector verified that the NED procedures were revised. The inspector also reviewed the maintenance records and determined that seven valves were involved. The records of stroke time and stroke measurement of these seven valves was audited by the inspector and was found to be acceptabl This item is close .0 Status of Target Rock SRVs The inspector reviewed the status of the plants 4 Target Rock 2 stage SRVs as a follow up to an earlier inspection (IR 84-31). That earlier inspection report described BECO's problems of high SRV leakage, high set points, and

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stuck pilot valve discs (this was the forerunner of sticking pilot discs

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and high set points at other plants). That report also described an MIT contracted metallurgical analysis performed for BECO and the conclusions and recommendations made by MI BECO implemented the MIT recommendation to change the pilot disc material from Stellite 6B to Stellite 21 and to

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perform on line testing of the SRV's at higher pressures to provide cushioning of the pilot disc to sea This inspector reviewed the current status of the valve Information obtained during this inspection is as follow The valves had been in service with the new Stellite 21 pilot discs from December 1984 through April 1986. There was one opening (remote actua-tion) on startup during pressure ascension and there were no further actus-tions during operation. The 4 valves were recently sent to Wyle Labora-tories for testin The licensee advised that phone information was received from Wyle Labora-tories on February 4 and 5, 1987, that:

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all 4 tested okay on the pilot valve sticking test

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3 were within i 1% of the set point on steam test, and I was slightly

. high (almost 2%) on the first opening

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Disassembly at W y le and inspection by Target Rock personnel is to take place in the near futur i

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The inspector discussed the planned Wyle inspections with the licensee and noted that care should be exercised during examination of these new Stel~ lite 21 pilot discs to assure they are free of the adhesive coating problems found on the earlier Stellite 6B disc The inspector was advised that the BWR owners group (BECO is a partici-par.t) has placed some trial precipitation hardening (PH) material pilot discs in service. BEC0 personnel had received some recent input that the PH discs may not be effective. They will make the BWR owners aware of their Stellite 21 pilot discs results which thus far appear encouragin The information could aid in resolving the Target Rock 2 stage SRV high set point industry problem .0 Exit Meeting The inspector met with the licensee's representative (identified in para-graph 1.0) at the conclusion of the inspection on February 6,1987, to summarize the findings of this inspection. The NRC Resident Inspectors, J. Lyash and T. Kim, were also in attendanc During this inspection, the inspector did not provide any written material to the licensee.

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