ML19326A329
| ML19326A329 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 04/12/1976 |
| From: | Roe L TOLEDO EDISON CO. |
| To: | Knuth D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| Shared Package | |
| ML19326A316 | List: |
| References | |
| NUDOCS 8002030149 | |
| Download: ML19326A329 (2) | |
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I TOLEDO April 12, 1976 EDISDN.
Docket No. 50-346 LOWELL E. ROE
%ce Presedent Dr. Donald F. Knuth, Director Faccht.es Deveicomens m,,,3g.324, Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
20055
Dear Dr. Knuth:
This letter is submitted in accordance with 10 CFR 50.55 as consummation of the Toledo Edison Interim Report, dated August 13, 1975, regarding the apparent deficiency related to Davis-Besse Nuclear Power Station Unit No. 1 reactor j
coolant pumps lAl, lA2, and 131.
Description of the Deficiency Indications exceeding the manufacturer's acceptance standards utilizing ASME Section III 1968 Edition for Class A vessels were discovered during the baseline inspection in the casing welds of Byron Jackson-furnished reactor coolant pumps lAl, lA2, and 1Bl. The specific indications noted were:
R. C. Pump Baseline Inspection
[-m Identification Radiographic Review Comments
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j lAl View E25-E26; Crack-type indication lA2 View A28-B28, slag or non-fusion approximately lh;" long.
1B1 View A2-A3, slag approximately 7" long Corrective Action Taken The indications were removed and the cavities examined by the liquid penetrant and radiographic methods to ensure defect re.moval. The cavities were then rewelded and the repaired areas reexamined by radiographic and liquid penetrant methods. The repaired areas were then radiographed by the Inservice Inspection Group to esta-blish the baseline documentation.
The pumps will be hydrostatically tested at the time of the reactor coolant system hydrostatic test.
Analysis of Deficiency
.I The reactor coolant pump casing welds were radiographed during original manufacture and certified to Byron Jackson by General Electric, Schenectady, to the acceptance standards of ASME Section III 1968 Edition for Class A vessels. Following the discovery in the baseline indications, the original GE radiographs were reviewed by both GE and Byron Jackson. Their review reconfirmed the acceptability of the
. original GE radiographs and the acceptability of the pump casings based on the jode requirements at the time of manufacture.
The original radiographs were made yL > by GE, utilizing Type AA film.
8002030M9 THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO. OHIO 43652
, $' Dr; Don;sid F. Knuth Prg's 2 April 12, 1976 i
turingthebaselineinspection, the radiographs were made utilizing Types 4:, 55, nd 65 films which provided a higher contrast than the Type AA film.
In addition, and as noted in IE Inspection Report No. 050-346/75-21, the GE penetraneter used for the original GE radiographs in some instances had partially masked the areas of concern on the original film.
These conditions contributed to the indications not being discovered at the time of manufacture, j
Safety Implications Any possible adverse safety considerations have been resolved with the timely finding, evaluating, repairing, and accepting of the three p mps' casing weld joint areas.
The baseline inspection program has provided additional confidence prior to placing the reactor coolant pumps into service.
Yours truly, Lowell E. Roe Vice President Facilities Development LER/jy O
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