ML19309F678

Responds to NRC 800216 Ltr Re Violations Noted in IE Insp Rept 50-306/80-03.Corrective Actions:Liquid Penetrant Examinations Conducted During Fuel Outage.Welds Buffed Smooth

ML19309F678
Person / Time
Site:	Prairie Island
Issue date:	03/12/1980
From:	Gilberts D NORTHERN STATES POWER CO.
To:	Fiorelli G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19309F677	List: ML19309F678
References
NUDOCS 8004300337
Download: ML19309F678 (2)

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NSIB l NORTHERN STATES POWER COMPANY M I N N E A PO LI S. M I N N E S OTA 55401

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March 12, 1980 Mr. G. Fiorelli, Chief Reactor Construction and Engineering Support Branch Region III, Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Fiorelli:

PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 and 50-306 In response to your letter of February 16, 1980, which transmitted Inspection Report 50-306/80-03, the following is offered:

Infraction Technical Specification 4.2.A.4 states in part, that, nondestructive inspections listed in Table TS 4.2-1, shall be performed as specified.

Northern States Power (NSP) Procedure No. NSP-PT-1, Revision 1, Section F-1 states, " Penetrant manufactures corresponding developer, as listed in Figure 1, shall be applied by spraying immediately af ter the penetrant removal and drying operation has been completed." This procedure requires a (5) minute drying time.

ASME Section V, Article 6, Subarticle T-646 states, "The developer shall be applied as soon as possible af ter penetrant removal . . ."

Contrary to the above, the inspector observed on January 17, 1980, during a liquid penetrant examination of Pressurizer Nozzles No. 156/2 and No. 164/2, line No. 6-2RC-20A and No. 6-2RC-20B, NAVC0 Drawing No. A7636(8), that developer had not been applied af t'.* penetrant removal until approximately 30 minutes on one nozzle and over ten minutes on the other nozzle.

Response

The liquid penetrant examinations observed by the inspector were not required to be performed by Prairie Island Technical Specifications Table 4.2.1 nor were they scheduled to be performed during this inspection period in the Inservice Inspection Program. These examinations were performed in addition to the Inservice Inspection examinations scheduled for that outage, based on problems being iden-tified in these areas at other operating plants.

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Mr. G. Fiorelli Page 2

• March 12, 1980 The liquid penetrant examinations were performed on the nozzle-to-safe and welds and safe end-to-piping welds of the Pressurizer Safety Lines. The welds that

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were examined are 155/1 and 163/1 for line numbers 6-2RC-20A and 6-2RC-20B respectively. The welds and line numbers are identified on an inservice inspec-tion isometric drawing number 2-ISI-30, Rev. O.

The welds identified above were liquid penetrant examined using Northern States Power Company Procedure NSP-PT-1, Rev. 1. The examinations were observed by the inspector, an Authorized Nuclear Inservice Inspector, and the NSP ISI engineer.

The examiner was performing the liquid penetrant examinations on both weld areas at once with a lag time in between to allow for the penetrant removal and drying operations. During the penetrant removal process, it was noted by the examiner that the surface condition of the areas were not acceptable for examination. The welds and adjacent areas had excessive grinding marks and the weld crown contour was not suitable for this type of examination.

The penetrant removal operation required more than normal due to this surface condition, and because two areas were being examined at once the drying operation was also lengthened. After the developer was applied it was obvious that the surface would have to be prepared before an acceptable examination could be performed.

The examiner completed an examination report identifying that the surface would have to be prepared before an acceptable examination could be conducted. The examiner also brought this to the direct attention of his field supervisor and  ;

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the NSP ISI engineer. The examination reports also identified the times for each step in the examination process, including the 30 and 20 minutes dry times.

Based on the results from these examinations, the surface of the weld and ad-jacent areas were buffed to eliminate the excessive grinding marks and the rough weld crown contour. Both areas were then re-examined in accordance with Procedure NSP-PT-1, Rev. 1, with an acceptable examination.

It is clear that the results of the initial examination were not accepted for the record because of a recognized need for surface preparation to obtain an inspectable surface. The record examination was performed in complete compliance with approved procedures. Therefore, we believe this citation for an alleged noncompliance should be retracted.

Yours truly, l b D. E. Gilberts Vice President Power Production I cc: Mr. G. Charnoff l

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