IR 05000327/1988045

Insp Repts 50-327/88-45 & 50-328/88-45 on 880920-28 & 27-28. No Violations or Deviations Noted.Major Areas Inspected: Snubber Surveillance Program & Licensee Action on Previous Insp Findings

ML20196D065
Person / Time
Site:	Sequoyah
Issue date:	11/22/1988
From:	Jape F, Lenahan J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20196D063	List: IR 05000327/1988045 ML20196D057
References
50-327-88-45, 50-328-88-45, NUDOCS 8812080195
Download: ML20196D065 (6)

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3 NUCLEAR REGULATORY COMMISSION o, E REGION 11 g e,,,, 101 MARIETTA ST., ATLANTA, GEORGIA 30323 Report Nos.: 50-327/88-45 and 50-328/88-45 Licensee: Tennessee Valley Authority 6N38 A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Docket Nos.: 50-327 and 50-328 License Nos.: DPR-77 and DPR-79 Facility Name: Sequoyah 1 and 2 Inspection Conducte : Sept ber 20-22 and 27-28, 1988 Inspector: s // t/M Date Signed J.J.Lgnpha'n Approved by: 4,1 ~

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Date Signed F. Jape, Chibf Test Programs Section g/

Engineering Branch Division of Reactor Safety SlHMARY

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Scope: This routine, unannounced inspection was in the areas of the Unit 1 snubber surveillance program and licensee action on previous inspection finding Results: In the areas inspected, violations or deviations were not identifie Weaknesses were identified in the licensee's snubber functional testing program. The testing procedures and methods are considered to be non-conservative. As a result, an unresolved item regarding additional snubber functional test lots was identified - Paragraph gDR ADOCK 050g7

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REPORT DETAILS Persons Contacted

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Licensee Employees

• T. J. Arney, QA Manager

• R. J. Beecker, Maintenance Superintendent o M. Cooper, Compliance Licensing Manager

• S. Doyle, Civil Engineer D. Lundy, Supervisor, Civil Engineering Unit, Office of Engineering

• R. C. Murray, Engineering Aid, Mechanical Maintenance S. J. Patel, Supervisory Design Engineer

• R. V. Pierce, Mechanical Maintenance Group Manager

• M. A. Purcell, Licensing Enginear P. B. Turner, Modification Engineer

• C. H. Whittemore, Licensing Engineer Other licensee employees contacted during this inspection included six engineer NRC Resident Inspectors K. Jension, Senior Resident Inspector G. Humphrey, Res! dent Inspector

• Attended exit interview , Snubber Surveillance Program - Unit 1 (70370)  ;

The inspector examined procedures and quality records related to the ,

snubber surveillance program and inspected snubbers on safety-related i piping systems. Acceptance criteria utfif zed by the inspector appear in Technical Specification (TS) 3/4. , Review of Snubber Surveillance Procedures The inspector examined the following procedures which control snubber c surveillance activities: ,

(1) Surveillance Instruction SI-162.1, Visual Examination of Snubbers ,

t (2) Surveillance Instruction SI-162.2, Snubber Functional Testing l (Hydraulic and Mechanical)  :

Procedure No. S!-162.2 lacked detail as discussed in paragraph c. below, i

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. . 2 b. Inspection of Snubbers The inspector performed a visual inspection of selected snubbers installed on sa fety-rela ted piping systems inside the Unit I containment buildin This inspection was conducted while the reactor coolant system was at ambient temperatur During the inspection, the inspector verified that the snubbers were not damaged, and that attachment of the snubbers to the supporting structure and piping was secure and for hydraulic snubbers, that fluid level in the reservoirs was above target levels. Curing the walkdown, the inspector noted that the pipe clamp on snubber 1-RCH-924 was twiste Work Request WR-B-784080 was initiated to correct this problem, c. Review of Quality Records The inspector reviewed the results of visual inspections and functional testing conducted July - September 1988 on the Unit I safety-related mechanical snubber No visually inoperable snubbers were identifie Review of the functional test results disclosad that four of the 73 snubbers tested in the original sczple lot failed to meet the snubber functional test acceptance criteris, Technical Specification 4.7. requires an aJditional lot equal to une-half the original lot size to be functional/ tested for each snubber failure in excess of two failures . However, the licensee subdivided the snubbers into five subgroups, per TS 4.7.9.a. , which permits grouping based on design and/or environment. The licensee has interpreted the TS to mean that ten percent of each subgroup constituted a sample lot, and that two functional test failures were pennitted in each subgrou The method used to determine the selection of snubbers for each subgroup is not defined in the licensee's surveillance procedure. Also, the licensee's TS interpretation which permits two functional test failures in each subgroup is not discussed in the surveillance procedure. The snubber functional test failures occurred as follows:

two failures in one subgroup and one failure in each of two other subgroups. Since the number of test failures did not exceed two in any subgroup, the licensee concluded that they complied with requirements of TS 3/4. The inspector noted that the licensee has not interpreted the TS in this same manner when performing previous snubber functional testin An exa+?le is the functional testing of Unit 2 snubbers performed in January - February 1988 (See Paragraph 5.c of Inspection Report No.

50-327,328/88-09). The inspector discussed the acceptability of l dividing the snubbers into subgroups for functional testing purposes l

with licensee engineer These discussions disclosed that the i

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.. 3 licensee concluded that subgrouping the snubbers for functional testing purposes was pennitted by the last sentence in TS 4.7. which states: "Each subgroup or group may be inspected independently in accordance with 4.7.9.b through 4.7.9.h."The requirement for functional testing of additional snubbers is addressed in TS 4.7. The last sentence of TS 4.7.9.a regarding subgrouping, states inspection of snubbers, not functional testing, and reference to TS 4.7. through 4.7.9.h in TS 4.7.9.a is considered by the inspector to be inane. This problem regarding functional testing requirements was identified to the licensee as Unresolved Item 327/88-45-01, Additional Snubber Functional Test Lots, pending further review by NR Within the areas inspected, no violations or deviations were identifie . Licensee Action on Pre tous Inspection Findings (Closed) Unre' Nd Item 327/86-24-02, Load Ratings of Mechanical Snubber Res ew of quality records during a previous inspection disclosed that the same size mechanical snubbers had different load ratings, depending on the date of manufacture of the snubbers. The snubbers were designated as either pre-NF or NF snubbers, with the pre-NF snubbers having a lower load rating than the NF snubber Since the design loads for pipe supports specified snubber size only and did not clearly designate what type snubber, i.e., NF or pre-NF snubber, and licensee maintenance personnel were not aware of the differences in load ratings oetween the NF and pre-NF snubbers, it was questionable whether the capacity of snubbers installed in various safety-related pipe supports complied with the design load In order to evaluate this problem, the licensee decided to confirm pipe support / snubber design Toad during the Unit 1 pipe support design confirmation stud This study was conducted by the licensee to reconstruct lost or missing Unit 1 pipe cupport design calcula-tion The inspector examined Sequoyah Design Criteria N SQN-DC-V-24.2, Supports for Rigorously Analyzed Category I Piping, which controlled the redesign effort for completion of the pipe support redesign calculation Af ter design loads acting on the snubbers were calculated, licensee engineers assumed that the snubber installed in the pipe support was pre-NF. If the pre-NF load rating for that size snubber was adequate, no further action was necessar However, if the design load acting on the snubber exceed the capacity of a Pre-NF snubber, the licensee performed a walkdown inspection to determine which type of snubber was installed in the support. If the installed snubber was found to be NF no further action was necessar However, if the installed snubber was found to be pre-NF, a design change authorization (DCA) was issued to replace the overloaded snubber. As a result of this evaluation, it was necessary to replace

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.. 4 the snubbers on pipe support numbers 1-CSH-469, 1-RCH-184, and 1-S!H-455. The inspector randomly selected the pipe supports listed below and reviewed the calculations and verified that proper size and type snubbers were specified on the pipe support drawings. Pipe support calculations examined were as follows: SIH 11, 13, and 15 RCH 26, 35,183,196,197, and 202, RHRH 8, CVCH 57,108,150, and '

163, AFDH-40, F0H-204, and 47A053-34 The fact that undersized snubbers had been installed in three safety-related pipe hangers was due to inadequate design drawings. A similar problem was identified for four Unit 2 pipe support This resulted in Violation 328/87-28-01, Hanger Design Loads Exceeded Snubber Capacity (See Inspection Report Number 50-328/87-28). Since the licensee has completed all necessary corrective actions to replace the undersized snubbers on both units, and corrective actions are in place to prevent reoccurrence of this problem, a separate violation will not be identified for Unit Unresolved item 327/86-24-02 is closed, (0 pen) Violation Item 327,328/88-09-01, Installation of Improper Type l of Bolts During Modification of the Movable Income Flux Mapping System. The license 9's actions to correct this violation were stated in their July 1, ono August 1,1988, responses to NRC. To correct this violation, the licensee replaced the bolts in Units 1 and 2 seal table radifications with the ASTM A-325 bolts as specified on the .

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design drawing The inspector examined the Unit 1 scal table modification and verified that the A-307 bolts were replaced with A-325 bolts. The inspector previously examined the Unit 2 seal table during the inspection documented in Inspection Report No. 50-327, 328/88-09 and verified that the correct bolts had beea installe The licensee identified the failure to close out work plans and update their procedures as the root cause of this violation. In order to correct tnis problem, the licensee conducted a review of all work plans which have been field rompleted for more than 90 days to determine if procedure revisions were necessary to complete the close out action for the work plan This review involved more than 500 work plans. Approximately 115 procedures were identified which required revision. None of the procedures affected the operability of Unit 2 while 7 were identified which required revision prior to restart of Unit 1. The licensee determined that the remaining 108 procedures did not effect operability of either uni The licensee subsequently determined that three additional procedures required revision prior to restart of Unit The ten procedure which affected Unit i restart were as follows: SI 82, SI 170.1, SI 170.2, SI 170.4, SI-205, IMI-99-RT-605 A, IMI-99-RT-605 B IMI-99-RT-612 A, and IMI-99-RT-630 B. The inspector reviewed these procedures and verified that they had been revised and updated prior to Unit i restart. The licensee has comritted to complete the revisions to the remaining procedures by March 29, 198 Violation item 327,328/88-09-01 will remain open pending completion of the licensee's corrective actions, f

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5 Exit Interview The inspection scope and results were summarized on September 28, 1988, with those persons indicated in paragraph 1. The inspector described the areas inspected and discussed in detail the inspection results listed belo Prcprietary information is not contained in this repor Dissenting comments were not received from the license Unresolved Item 327/88-45-01, Additional Snubber Functional Test Lot ;

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