IR 05000338/1988012

Insp Repts 50-338/88-12 & 50-339/88-12 on 880420-22.No Violations or Deviations Noted.Major Areas Inspected:Snubber Surveillance Program & Followup on Licensee Action on Previous Insp Findings

ML20151H406
Person / Time
Site:	North Anna
Issue date:	07/06/1988
From:	Jape F, Lenahan J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20151H402	List: IR 05000338/1988012 ML20151H400
References
50-338-88-12, 50-339-88-12, NUDOCS 8808010274
Download: ML20151H406 (6)

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Report Nos.: 50-338/88-12 and 50-339/88-12 Licensee: Virginia Electric and Power Company Rich ond, VA 23261 Docket Nos.: 50-338 and 50-339 License Nos., NPF-4 and NPF-7 Facility Name: North Anna 1 and 2 Inspection Conducted: April 20-22, 1988 Inspector: h .,~h 7/4/ff-Date Signed

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[J.J.Le;4 nan Approved by: Nd6f C Jape, Secti'on Chief k g dM

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Division of Reactor Safety

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SUMMARY t Scope: This routine, unannounced inspection was in the areas of snubber surveillance program and follow-up on licensee action on previous inspection finding Results: No violation or deviations were identifie Two unresolved items were identified: One concerning the evaluation of visual snubber inspect. ion results; Secondly, corrective actions on snubbers with fluid leaks, Paragraph ;

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REPORT DETAILS Persons Contacted Licensee Employees

1. M. L. Bowling, Assistant Station Manager

• • R. O. Enfinger, Assistant Station Manager

• • S. P. Hamill, Supervisory ISI Engineer

• • L. N. Hartz, Instrumentation Supervisor

• 0. A. Heacock, Superintendent of Technical Services

• • 0. B. Roth, Nuclear Specialist

1. J. A. Stall, Superintendent, Operations

• • G. A. Swann, Senior Engineering Technician tiRC Resident inspectors L. King

1. J. Caldwell

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• Attended exit interview

• • Participated in April 28 conference call and attended exit intervie # Participated in April 28 conference call Snubber Surveillance Program - Units 1 and 2 (70370)

The inspectcr reviewed procedure: and quality records related to the snubber surveillance progra Acceptance criteria examined by the inspector appear in Units 1 and 2 Technical Specification (TS) 3/4.7.1 Review of Snubber Surveillance Procedures ,

The inspector examined the following procadures which control the .

snubber surveillance program:

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(1) Procedure Number 1-PT-79.0, Snubber Maintenance Tracking l Pro;edure

(2) Procedure Numbers 1-PT-79.1 and 2-PT-79.1, Hydraulic Snubbers l Accessible for Visual Inspection During Reactor Operation l (3) Procedure Numbers 1-PT-79.2 and 2-PT-79.?, Hydraulic Snubbers Not accessible for Visual Inspection during Reactor Operation l l

(4) Procedure Numbers 1-PT-79.3 and 2-PT-79.3, Hydraulic Snubber !

Functional Testing (5) f40rth Anna Power Station Inservice Inspection Manual. Procedure 151-3,0 i

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, 2 (6) Special Test Procedures 1-ST-72 and 2-ST-48, large Bore Snubber Accumulator System Troubleshooting b. Review of Quality Records ,

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The inspector examined the following quality records:

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l (1) Results of as-found visual inspections performed on Unit 1 ,

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inaccessible snubbers in May - September 1984, November -

l December 1985, and April - June 198 l

}' (2) Results of visual inspections performed on the Unit i large bore !

snubbers in December 198 The small bore snubbers were not

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inspected at this tim ,

l (3) Resul t;; Of as-lef t visual inspections performed on Unit 1 inaccessible snubbers in June 1987 and September - October 198 (4) Results of functional tests performed on Unit i large and small f

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bore snubbers in November - December 1985 and April - June 198 (5) Results of as-found visual inspections performed on Unit 2 inaccessible snubbers in ' february - March 1986 and August - l October 1987 l (6) Results of functional tests performed on Unit 2 snubbers in February - March 1987 and August - October 198 '

(7) Maintenance Work Order numbers 5900061075, 5900064664, I

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5900068591 and 5900068593 l

i (8) Engineering Work Request (EWR) numbers85-785, sd-135, 150-152, >

j 168, 178, and 87-383, 391, 401, 434, 436, 446, 447, 619, and i l 65 (9) The Engineering Mechanics Technical Reports (EMTR) listed below !

were examined: i

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- EMTR 86-HFW-002, Review of Technical Justification for (

.I Testing Valve Blocks of Large Bore Snubbers to Meet '

Functional Test Requirements l

! - EMTR 87-MFW.002, Technical Justification for Valve Block !

Testing of Large Bore Snubbers (Without Removing Entire !

Snabber Assemblies) to Meet functional Test Requirements

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EMTR-86-MSW-002, Verification of Consultant's Report of f Snubber Acceptance Criteria for Surry Power Station L

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- EMTR 87-MFW-005, Review of Functional Test Results Outside of Administrative Limits for Small Bore Snubbers in April 1987, Refueling Outage

- EMTR-87-HFW-009, Review of Milwaukee Snubber Three Part Functional Test Results for the September 1987 Refueling Outage

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Review of the functional test results disclosed the following problem: During the February - He.rch 1986 Unit 2 as-found visual inspections, an empty valve block was discovered on snubber

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2-RC-HSS-005C and a pin was found missing (disengaged) on snubber 2-FW-HSS-63 Functional tests could not prove these snubbers operabl These problems were evaluated on EWRs86-150 and 151,

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respectively. The engineering evaluations on the EWRs stated that the failures were considered to be random since no other failures were found with similar conditions and that the cause was not known. Using ,

these evaluations and acceptance criteria given in TS 4.7.10, the licensee concluded that it was not necessary to count these visual inspection failures in determining the next visual inspection peri During the April - June 1987 Unit 1 as-found visual inspections, a ,

j disengaged pivot pin was found on snubber 1-RH-HSS-109B and an empty i valve block was found on snubber 1-RC-HSS-005B. These problems were e evaluated on EWP.s87-383 and 87-434, respectively. The evaluations 3

. on these EWRs also stated that the failures were considered to be random since no other snubbers were found with tFese conditions, and

, the causes were not know , The inspector questioned the conclusions stated in EWRs86-150, l 86-151,87-383, and 87-434 and discussed the evaluations with -

> licensee engineers. These discussions disclosed that the licensee's *

1 basis for reaching their conclusions were definitions and statements  !

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contained in a draft copy of ASME OM4, Examination and Performance 1 Testing of Nuclear Power Plant Dynamic Restraints (Snubbars) dated [

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September 1986 (Revision 1. Draft 7). Licensee engineers stated that l t

they concluded that failures described on the EWRs met the definition  :

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of isolated failures per OM4 and are believed to be random event ;

) However, after review of OM4, the inspector concluded the failures l met the definitions of either "Maintenance, Repair or Installation i Induced Failures." or "Unexplained Failures." The OM4 definition for an explained failure states that unexplained failures include all

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failures for which the cause can not be determined. This agrees with '

statements made en the EWR ;

The improper classification of the visual inspection failures was ,

l apparently due to use of an inadequate procedure in the engineerir,9 l

cvaluations. The licensee cemitted to revising the procedure for l classification of visual snubber inspections failures and providing

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a copy of the revised procedure to NRC Region II. The prucadure will list specific examples which can be attributed to

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random events, isolated damage, or unexpected damage per TS 4.7.1 The licensee will also provide NRC pngien 11 with an assessment of the effect of the misclassification (: the snubber visual ins, action failures discussed above on the selection of the subsequent visual inspection interval Pending review of this document by NRC Region 11, this item was identified to the licensee as Unresolved Item 338, 339/88-12-01. Evaluation of Snubber Visual Inspection Failure The inspector questioned the licensee's corrective 6ction program regarding the large nueer of Unit I snubbers found with empty reservoirs during th; April - June 1987 visual inspection Low fluid level was al<,o found in the Unit 1 steam generator snubbers during inspections conducted in September and December 198 In addition, during the September inspection, five small bore snubbers were identified with low fluid levels, although the snubbers had been recently inspected (in June) prior to returning Unit 1 to power operation. There were no records which indicated that the small bore snubbers had been inspected in December 198 The inspector's concern is whether the licensee's preventative maintenance program for i the correction of fluid leaks from the snubbers was adequate to j resolve the problem so that fluid leakage will not reoccur during the l next cycle. This problem was identified to the licensee an Unresolved i Item 338/88-12-02, Preventative Maintenance Program 'or the Correction of Fluid Leaks from Hydraulic Snubbers, pending further review by NRC.

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During review of fsnctional tests performed on Unit I snubber numbers 1-RC-105A,1-RC-863,1-RS-205B, and 1 SHP-205, the inspector noted  ;

that the functional test results exceeded the licensee's acceptance ,

criteria for lock up. The functional tests were performed because of empty reservoi s found during visual inspection of the snubbers. An  ;]I evaluation of the functional test results was documented on EWR i 87-401, and in EM TR-87-MFh 0C'. These reports state that the i justification for accepting the above results are documented in i assorted Engineering Nechanics *.alculation These calculations will l be reviewed during a fi %re ins;cction. This item was identified to the licensee as Inspector Folicwup Item 338/88-12-03, Review i Calculations Accepting Snubber Fu.-i onal i Test Results Which Exceed ,

licensee's Establishe i limits, j

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i l Within the areas inspected, no violations or deviations were j

identified.

l l 3. Licensee Action on Previous Enforceme ! Matters l

(Closed) Unresolved item 338/87-27-01 Review of Licensee's Er " + ring Evaluation of Snubber Visual Inspection and Functional Test Re!. n. The inspector reviewed engineering evaluations performed on snubbw. with functional test results which did not comply with the functional test limits specified in the licensee's procedures. The details of this review

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are discussed in paragraph 2.b abov Unresolved Item 338/87-27-01 is close . Exit Interview The inspection scope and findings were summarized on April 22, 1988, with those persons indicated in paragraph 1 above. The inspector described the areas inspected and discussed the inspection findings. No dissenting coments were received from the license Subsequent to the inspection, on April 28, 1988, a telephone conference call was held with the licensee to discuss the licensee's methods of categorizing visual inspection failures. On July 6,1988, during a meeting held in the Region II offices, the licensee was informed of the inspection findings. The following new items were identified: Unresolved Item 338, 339/88-12-01, Evaluation of Snubber Visual (

Inspection Unresolved Item 338/88-12-02, Preventative Maintenance Program for [

Correction of Fluid Leaks Unit 1 Hydraulic Snubber #

l Inspector Followup Item 338, 339/88-12-03 Review Calculations l Accepting Snubber Functional Test Results which exceed Licensee's  !

Established limit !

l During the July 6,1988 meeting, the licensee comitted to provide to  !

NRC Region !! within 30 days of receipt of this inspection report, a copy ,

of their procedure for classification of visual snubber inspector failures,  !

and the effect of the incorrect classification of visual snubber inspector  !

failures on the selection of the subsequent visual inspection interva l The licensee did not identify as proprietary any of the materials provided  !

to or reviewed by the inspectors during this inspectio !

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