IR 05000327/1986067

Insp Repts 50-327/86-67 & 50-328/86-67 on 861112-14.No Violations or Deviations Identified.Major Areas Inspected: Licensee Actions on Previous Insp Findings & Licensee Identified Item

ML20207J367
Person / Time
Site:	Sequoyah
Issue date:	12/24/1986
From:	Jape F, Lenahan J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20207J356	List: IR 05000327/1986067 ML20207J352
References
50-327-86-67, 50-328-86-67, NUDOCS 8701080419
Download: ML20207J367 (5)

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UNITE 3 STATES

[Sm itig##o NUCLEAR REGULATORY COMMISSION

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j 101 MARIETTA STREET N ,

• ATL ANTA. GEORGI A 30323  ;

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Report Nos.: 50-327/86-67 and 50-328/86-67  :

Licensee: Tennessee Valley Authority 6N38 A Lookout Place l 1101 Market Street -

l Chattanooga, TN 37402,-2801

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Docket Nos.: 50-327 and 50-328 License Nos.: DPR-77 and DPR-79 t

Facility Name: Sequoyah 1 and 2 ,

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Inspection Conducted: No mber 12-14, 1986 -

Inspector: e --

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J.J[priahan .

. Date Signed j Approved by: M ;f, /1)d%dMvAs /b/N /f6 F. Jape, Sect 1'on Chief '

. # t/ , i.Date Signed Engineering Branch

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Division of Reactor Safety SUMMARY Scope: This routine, unannounced inspection was conducted in the areas of licensee actions on previous inspection findings, and a licensee identified item (LER).

Results: No violations or deviations were identifie ;

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i REPORT DETAILS

' Persons Contacted Licensee Employees

• M. S. Ali, Technical Supervisor, Piping Analysis, Office of Engineering .

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• G. S. Bowles, Mechanical Maintenance Supervisor

• G. B. Kirk, Compliance Licensing

• K. L. Mogg, Supervisor, Civil Engineering Office of Engineering R. C. Murray, Engineering Aide, Mechanical Maintenance

• A. Purre11, Licensing Engineer ,

• P. R. Wallace Plant Manager l Other licensee employees contacted included three engineers and one ,

technicia NRC Residant Inspectors P. E. liarmon K. M. Jenison

• W. K. Poertner

• Attended exit interview Exit Interview The inspection scope and findings were sunnarized on November 14, 1986, with those persons indicated in paragraph 1 above. The inspector described the areas inspected and discussed in detail the inspection findings. No dissenting comments were received from the license The licensee did not identify as proprietary any of the materials provided to or reviewed by the inspector during this inspectio . Licensee Action on Previous Enforcement Matters (0 pen) Unresolved item 327, 328/86-24-02, Load Ratings of Mechanical Snubber Review of quality records during an inspection conducted on March 18-21, 1986 (see inspection report numbers 50-327, 328/86-24)

disclosed that the same size mechanical snubbers had different load ratings, depending on date of manufacture. Based on manufacture date, snubbers were designated as either " Pre-NF" or NF snubbers. The NF designation refers to snubber designed in accordance with requirements of Subsection NF of Section !!!, Division I of the 1977 ASME Code. The load rating of the " pre NF" and NF snubbers are listed in the Table 1 below:

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TABLE 1 Load Rating (in pounds)

Snubber Size Pre-NF NF PSA 1/4 250 350 PSA 1/2 500 650 PSA 1 1000 1500 PSA 3 3000 6000 PSA 10 10000 15000 PSA 35 35000 50000 PSA 100 100000 120000 Since the pipe support drawings only designate snubber size, e.g.PSA-1, and licensee maintenance personnel were not aware of the difference in load ratings between NF and Pre-NF snubber, the inspector questioned whether the installed snubbers complied with design loads specified on piping support drawings. In order to evaluate this problem, licensee personnel performed a walkdown inspection and identified all pipe supports that had pre-NF snubber The pre-NF snubbers can be identified from information engraved on the snubber identification plate, and also by color of paint. The pre-NF snubbers were painted with a white epoxy paint. The NF snubbers are painted with a gold metallic paint. A total of 233 pre-NF snubbers were identified in Unit 2 during the walkdown inspection. The walkdown inspection to identify pre-NF snubbers installed in Unit 1 was being conducted by licensee personnel during this inspection. The locations, size, and rating of the Unit 2 pre-NF snubbers were tabulated and submitted to Office of Engineering design personnel for evaluation. The design personnel compared updated design loads for normal / upset and faulted conditions with the original design loads shown on the pipe support sketches and with the existing snubber ratings (capacities). Four supports were identified during this evaluation where updated design loads exceeded capacity of installed pre-NF snubbers. These supports are listed in Table 2 belo TABLE 2 Rating Snubber For Faulted Updated Previous Support number Size Load * Design Load Design Load 2 RCH-184 PSA-1 2000 2143 2144 2 AFDH-229 PSA-3 6000 8943 5919 2 CVCH-154 PSA-1 2000 2270 2300 2 CSH-457 PSA-1 2000 4616 602

• 0ased on June 2,1986, letter from Pacific Scientific Company to TVA, Pre-NF snubbers have one time _ load rating of twice that indicated on identification  :

plate.

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Updated design loads were obtained from pipe stress analyses based on as-built conditions. The majority of the design loads decreased or remained unchanged. For support number 2 CSH-457, the large increase in design load was the result of a design base accident analysis performed on the contain-ment spray (CS) piping (containment spray) system. The large increase in design load for support 2 AFDH-229 was due to a design error which resulted in recording the normal / upset load as the faulted load on the pipe support drawing. The updated design loads increased by more than 20 pounds on sixteen additional supports. The rating of the installed snubbers was adequate on these supports. However, evaluations were performed to verify the stresses in the existing pipe support structural steel were within code allowable values for the updated design loads. The inspector reviewed the calculation entitled "SQN2 Early Model Snubber Evaluation" which were performed to evaluate the pre-NF snubbers. These calculations included correspondence with Pacific Scientific Company which specified pre-NF load capacities for normal / upset and faulted conditions, tabulation of previous and updated design loads and comparison with capacity of installed pre-NF snubbers, and evaluation of adequacy of existing structural steel in pipe supports where the updated design loads increased more than 20 pounds above the previous design load. No modifications were necessary to the structural steel portions of the supports due to the increased updated design load For the four supports listed in Table 2 the existing pre-NF snubbe s were replaced with NF snubbers that meet the updated design loads. The spector examined the design documents which show details of the snubber change ou These documents were as follows: Sketch number BE-4180-2CS-2-H21-457, Sheets 1 to 3 for replacement of Pre-NF PSA 1 snubber with new NF PSA 3 snubber in support number 2 CSH-457. Capacity of PSA 3 snubber is 10380 pounds versus updated design load of 4616 pound Sketch number BE-4180-2CVC-2-H34-154 Sheet 1 for replacement of pre-NF PSA 1 snubber with new NF PSA 3 snubber in support number 2-CVCH-154. Capacity is 10,380 pounds versus updated design load of 2270 pounds, Sketch number BE-4180-2RC-2-H36-184, Sheets 1 and 2, for replacement of Pre-NF PSA 1 snubber with new NF PSA 3 snubber in support number 2 RCH-184. Capacity is 10,380 pounds versus updated design load of 2143 pounds, Sketch number BE-4180-2AFD-H3-229, Sheet 1, for replacement of Pre-NF PSA-3 snubber with new NF PSA 3 snubber in support number 2 AFDH-22 Capacity is 10,380 pounds versus updated design load of 8943 pound The inspector examined support numbers 2 AFDH-229 and 2 CSH-457 and verified that new NF PSA 3 snubbers had been installed as required by the above listed design documents. During the field inspection, the inspector also examined the following snubbers 2 CSH-7, -37. -65, -67, and -456, and 2 SHK-43 i. . -

The inspector noted that snubber numbers 2 CSH-65, -66, and -67 were pre-NF snubbers while the remaining were NF snubbers. The inspector examined the tabulation of pre-NF snubbers and verified that these snubbers and their proper size were liste Discussion with licensee engineers disclosed that snubber number 2 AFDH-229 is installed on a section of non-safety-related piping and that snubber 2 WH-957 will be deleted by the leak before break analysis to be performed

in accordance with the revised General Design Criteria The safety significance of the need for replacement of the above listed 4 snubbers will be determined after further review by NRC Region II. Pending.this further review and completion of the Unit 1 pre-NF snubber evaluation Unresolved Item 327, 328/86-24-02 will remain ope . Unresolved Items Unresolved items were not identified during the inspectio . Licensee Identified Item (LER)

(0 pen) LER (86-046) Personnel Error Resulting in Inadequate Verification of Snubber Drag Force Trending The licensee reported to NRC Region II on November 11, 1986, that a j

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personnel error in calculation of increase of snubber drag force since the last previously performed functional test resulted in failure to identify six snubbers which had drag forces which increased by more than 50 percent since the last previously performed functional tes Technical Specifica-tions 4.7.9.e.3 and 4.7.9.f require that an engineering evaluation be performed for snubbers which show an increase in drag force of more than 50 percent since the last functional test of that snubber. The inspector identified this problem for four of the six snubbers during a review of test results conducted during a previous inspection and identified it to the licensee as part of Unresolved Item 327, 328/86-24-02 (see Inspection Report 50-327/86-24 and 50-320/86-24). The inspector was unable to determine at that time whether their problems had been identified and evaluated by licensee personnel. However, review of the problem at the time disclosed that since the measured drag forces were still well below the maximum two percent of snubber capacity specified in the licensee's test acceptance criteria, this problem had no immediate safety significance. The inspector discussed this problem with the licensee during the exit interview and informed the licensee that the majority of Region II licensees have removed or modified the requirement for engineering evaluation of a functional test with an increase of more than 50 percent in drag force over a previous functional test when the most recent drag test results were less than the licensee's test acceptance criteria. This LER remains open pending further review and resolution of Unresolved Item 327, 328/86-24-02.

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