ML20108A455

Responds to NRC Re Violation Noted in Insp Rept 50-410/84-08.Corrective Actions:Transverse Indication in Weld ICS 57-8 Swf Removed & Weld Repaired

ML20108A455
Person / Time
Site:	Nine Mile Point
Issue date:	09/07/1984
From:	Mangan C NIAGARA MOHAWK POWER CORP.
To:	Starostecki R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20108A452	List: ML20108A455
References
(NMP2L-0155), (NMP2L-155), NUDOCS 8411140602
Download: ML20108A455 (9)

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NIAGARA asOHAWK POWER CORPORATION /300 ERIE BOULEVARD WEST. SYRACUSE. N Y.13202/ TELEPHONE (315) 474-1511 September 7, 1984 (NMP2L 0155)

Mr. R. W. Starostecki, Director Region I Division of Project and Resident Programs 631 Park Avenue King of Prussia, Pennsylvania 19406 Nine Mile Point Unit 2 Docket No. 50-410

Dear Mr. Starostecki:

Enclosed is our detailed response to the Notice of Violation dated August 8, 1984 and the accompanying Inspection Report No. 50-410/84-08.

Very truly yours, .

Wh C. V. Mangan Vice President i Nuclear Engineering & Licensing l I

Enclosure I

CVM/GG/pbd xc: R. A. Gram, Resident Inspector Project File (#0122H) 0\ '

8411140602 841019 PDR ADOCK 05000410 ,

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NIAGARA M0 HAWK POWER CORPORATION NINE MILE POINT - UNIT #2 DOCKET No. 50-410-Response to Notice of Violation Attached to NRC Inspection Report No. 50-410/84-08 The first violation was identified'as follows:

Violation A 10 CFR 50, Appendix B, Criterion IX, requires that special processes, such as non-destructive testing, be controlled and accomplished using qualified procedures.

Rite Radiographic Examination Procedure RTP-3-lC, dated January 4,1984, requires that "all information which would have significant bearing upon product quality shall be recorded."

Contrary to the above, a review of site radiography during May 14-25, 1984, disclosed weld 01-14-2-MSS-44-1-88, film area B, has a linear indication, that could have a significant bearing on product quality, that was not recorded or dispositioned on either of the licensee's 100%

radiographic film reinterpretation programs.

This is a Severity Level V violation (Supplement II).

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Docket No'. 50-410 Page 2' The following is submitted in response to'this violation.

The alleged violation references a procedure which is applicable to radiography at the site. The weld in question is a shop weld which was ,

radiographed in 1982. Although there is no code requirement to record acceptable discontinuities / indications on a radiographic ex6mination report, because of the concerns identified in the Construction Assessment Team Report, the ITT Grinnell site radiographic procedure was revised to include a requirement to document acceptable discontinuities / indications for field radiography. This requirement is imposed on ITT Grinnell site radiographic examinations performed after the procedure revisions and was not ' intended to be retrofitted on prior radiographic examinatien reports. During the inspection, the indication on the radiographic examination film ~in question was demonstra'ted to be an acceptable surface mark on the outside diameter of the pipe.

For these reasons Niagara Mohawk does not believe this is a violation.

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. Docket No.'50-410 Page 3 The second violation was identified as follows:

Violation B 10 CFR 50.55(a) requires that the reactor' coolant pressure boundary be constructed in accordance with the ASME III Code for Class I systems.

American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code, Section III, NB5320, requires that indications observed in interpreting radiographic film are recorded and dispositioned. The proper disposition of linear indications that ' exceed code requirements is repair of the affected area.

Contrary' 'to the above, an NRC review of radiographs during May 14-25, 1984, disclosed the following code inspected and accepted weld, ICS-57-8 SWF, contained a detectable, unacceptable transverse linear indication that had not been identified or dispositioned during several radiographic film reviews.

This is a Severity Level IV violation (Supplement-II).

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l Docket No. 50-410 Page 4 l s

P The following is submitted in response to this violation:

Niagara Mohawk Power Corporation has reviewed weld ICS-57-8-SWF as a >

result of this notice of violation and agrees that the transverse linear indication does require repair.

Corrective Action:

The transverse indication in ICS 57-8 SWF was removed and the weld repaired in accordance with N&D IG 2855. N&D IG 2855 was closed June 8, 1984. Concurrent ultrasonic examination revealed that the repair area 4

was below minimum wall and this was documented on N&D IG 2940. The condition was accepted-as-is based upon stress and minimum wall calculations which showed that the condition would not affect component integrity, system design, or system operability. Niagara Mohawk considers this to be an isolated event for the following reasons:

1. During the radiograph reviews previously performed by Niagara Mohawk l

only two welds were identified as requiring repair; and

2. The weld cited in this violation was the only one out of 168 pipewelds inspected by the Nuclear Regulatory Commission that 1

required repair.

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Docket No. 50-410 Page 5 Schedule-The corrective actions noted above have been completed.

The third violation was identified as follows:

Violation C 10 CFR 50, Appendix B, Criterion V, requires that activities be prescribed by documented procedure or drawings and be accomplished in accordance with these instruction, and that they include quantitative acceptance criteria.

Piping system Fabrication -Specification P301B and drawing RHS-66-34-SW0ll invokes ASME Section III, paragraph NB3000, which requires that cross sectional thickness not be reduced below the minimum values specified for the base material. ASME Section II, SA106 (specification for the base material used) specifies that 6" diameter, schedule 40 pipe nominal wall thickness to be .280" + 121/2%.

l l Contrary to the above, an NRC ultrasonic thickness verification performed during May 14-15, 1984, disclosed weld RHS-66-34-SW0ll which had been inspected and accepted was below minimum wall thickness. The ultrasonic measured wall thickness was .230" for 75% of the circumference around the weld. ASME Section 11 minimum wall thickness requirement for a 6" l

! diameter schedule 40 pipe is .245".

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Docket No. 50-410 Page 6' This is a Severity Level V violation (Supplement II).

The following is submitted in response to this violation:

Visual inspection indicated the weld was acceptable. The weld was not examined for thickness since tne radiography did not exhibit changes in density typical of a thickness problem.

The manufacturer's minimum wall thickness requirement for SA106 pipe is used as the acceptance criterion for weld thickness during fabrication and erection processes. The ASME code reccgnizes design thickness only, as the acceptance criterion for these cases, and this will always be less than the manufacturer's minimum thickness requirement. It is not normal construction practice to perform additional thickness checks during 4 m b5%

f P ic: tier since the material manufacturer certifies conformance with all manufacturing code and specification requirements.

Low areas that are severe enough to encroach significantly on design j

thickness would be detected by radiographic examination and would then be l subject to additional examinations, including a thickness check.

l Therefore, it is Niagara Mohawk's position that if there is no change in esd density on the radiograph then wpTl thickness is within acceptable design limits. The evaluation of the weld cited in the violation supports this position since the radiography showed no density change and, upon further analysis, the weld proved acceptable as is. This analysis is documented on N&D 1G-2854, which was generated to resolve the inspector's concern.

Docket No. 50-410 Page 7 CORRECTIVE ACTION No corrective action is considered necessary.

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Response to General Concerns The transmittal letter to Inspection Report No. 50-410/84-08 expressed a concern regarding the effectiveness of corrective actions taken as a result of the Construction Assessment Team Inspection Report. The letter indicates that Violations A and B suggest that Niagara Mohawk's radiograph reinspection / reinterpretation program may not have been effective. As stated in our above response, Niagara Mohawk believes alleged Violation A is not a violation and alleged Violation B represents an isolated event. Hence, we believe that these alleged violations do not reflect a deficiency in Niagara Mohawk's reinspection / reinterpretation program. We expect that the independent audit now being conducted will confirm the effectiveness of our corrective actions for this activity.

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