IR 05000220/1993007
| ML20044G080 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 05/12/1993 |
| From: | Kaplan H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20044G078 | List: |
| References | |
| 50-220-93-07, 50-220-93-7, 50-410-93-07, 50-410-93-7, NUDOCS 9306020012 | |
| Download: ML20044G080 (4) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION I
REPORT NO.
50-220/93-Ogand 50-410/93-07 DOCKET NO.
50-220 LICENSE NO.
DPR-63 LICENSEE:
Niagara Mohawk Power Corporation 301 Plainfield Road
Syracuse, New York 13212
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FACILITY NAME:
Nine Mile Point Units 1 and 2 INSPECTION AT:
Scriba, New York INSPECTION CONDUCTED:
April 12-16,1993
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INSPECTOR:
Herbert J. Naplan, Reactor Engineer Date Materials Section, EB, DRS Y
U APPROVED BY:
E. H. Gray, Chief Date
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Materials Section, EB, DRS Areas Insoected: The licensee's inservice inspection (ISI) program results for the Unit 1
1993 spring outage and the continuing erosion / corrosion (E/C) program results for Units 1
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and 2. Both were reviewed to evaluate the findings and to ascertain that the activities were performed in compliance with licensee commitments and regulatory requirements.
Results: Within the scope of this inspection, the results and associated records of the ISI and E/C programs were reviewed.. The review indicated that no significant rejectable indications
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were found in the Unit 1 ISI program, and that no chronic crosion/ corrosion conditions exist
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in Units I and 2.
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DETAILS
1.0 INSERVICE INSPECTION RESULTS FOR UhTT 1 (INSPECTION PROCEDURE 73753)
The inspector reviewed the ISI results of exammations conducted during the spring 1993 refueling outage. The program was initially reviewed in February 1993 (IR 50-220/93-02).
A review of the results, which were tabulated in a summary report prepared by General Electric, the ISI subcontractor, indicated that 480 components were examined in accordance with ASME Section XI,1983 Edition, including addenda through Summer 1983. The 480 components included one reactor vessel pressure retaining weld,182 piping welds, including longitudinal welds where present,131 bolts, and numerous attachments and supports. Except for a few isolated linear liquid penetrant and magnetic particle surface indications, which
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were removed by light grinding, no rejectable indications were found. No repair welding was employed in any case. A sampling of supponing non-destructive examination (NDE)
records pertaming to the above examinations, including inspections after repairs, revealed no inconsistencies or deviations, and confirmed conformance to Code requirements.
1.1 Conclusion The ISI examinations did not reveal any significant rejectable indications. Based on the findings of Inspection No. 50-220/93-02 and this inspection, the inspector concluded that the ISI components were selected for examination in accordance with the program submitted to the NRC and in accordance with the ASME Code with the exception of granted relief requests.
2.0 EROSION / CORROSION RESULTS FOR UNIT 1 AND UNIT 2 (IP-49001)
The inspector reviewed the E/C results for Umts 1 and 2. The programs were initially reviewed in March 1992 and February 1993 for Units 1 and 2 (see Inspection Report Nos.
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50-414/92-07 and 50-220/93-07 respectively). A review of a summary tabulation for Unit I
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during the period of March 1983 through February 1993 indicated that a total of 187 components were inspected by ultrasonics for wall thickness thinning. Of this group, only
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eight required further evaluation which resulted in repairs of two extraction steam nozzles, identified as E17N006 and E17N003. The repairs utihzed interim patch plates because
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replacement material was not available. For Unit 2, a total of 310 components were examined for wall thickness thinning. Of this group,28 required evaluation, resulting in eight replacements and one repair, using a patch plate. A sampling of NDE records representing these results, in addition to the engineering evaluations, were reviewed and
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found to be consistent with the summary results.
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Conclusion The E/C program in Units 1 and 2 appeared to be comprehensive and in accordance with j
EPRI guidelines. Where thinning was observed, appropriate action, including evaluation, i
repair, or monitoring, has occurred.
l 3.0 UNIT 1 CONTROL ROD HOUSING BO'ITOM REACTOR VESSEL HEAD LEAKAGE
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As the result of leakage (20-80 drops per minute) in two bottom head type 304 stainless steel l
stub tubes (#34-51 and #50-35), the licensee elected to roll the type 304 housing against the i
l stub tube to the extent of increasing the housing inside diameter (ID) by 0.070". The rolling operation, which was employed previously, was performed in accordance with
ABB/ Combustion Engineering Procedure NMP-1004)01. The inspector verified that proper ID dimensions were achieved as verified by the licensee's QA. After rolling the ID, the
lubricant was removed and the surfaces cleaned with a non-halogen solvent. Following
rolling, the system was pressure tested at 630 psi and 490*F with no leakage observed.
4.0 FEEDWATER NOZZLE "A" ULTRASONIC EXAMINATION (UNIT 1)
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As the result of the licensee's commitment to inspect feedwater nozzles in December 1980,
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ultrasonic examination of the "A" nozzle in a 1989 outage revealed several indications in the
bore area. In the current 1993 outage, ultrasonic inspection of nozzle "A" was repeated
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using both 5% and the Code allowable 10% notches. The licensee reported that although a
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base signal associated with the original indications was observed, no tip signal was seen. On the basis of these findings, the licensee concluded that the indications appeared to be due to e
scratches or ID surface irregularities and not from ID cracking. The inspector had no further
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questions on the feedwater nozzle "A" examination.
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5.0 EXIT MEETING
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The findings of the inspection were discussed with licensee's management in an exit meetmg
on April 16, 1993. The licensee did not take issue with any of the findings discussed during
the exit meeting. A list of attendees is attached to this report as Attachment A.
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ATTACHMENT A Niacara Mohawk i:
J. Burton, Manager, Quality Assurance, Unit 1 K. Dahlberg, Plant Manager, Unit 1 L. Dick, Supervisor, Quality inspection, Unit 2 P. Lavallee, Supervisor, Quality Inspection, Unit 1 M.12onard, lead Engineer, Inspection Programs M. McCormick, Plant Manager, Unit 2 T. Oldfield, Quality Inspection, Unit 2 J. Perry, Vice President, Quality Assurance A. Pinter, Site Licensing Engineer J. Swewszkowski, Quality Inspection, Unit 2 NRC H. Kaplan, Sr. Reactor Engineer R. Plasse, Resident Inspector
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