ML19317G682
| ML19317G682 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 05/30/1972 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Rich Smith NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML19317G673 | List: |
| References | |
| NUDOCS 8003250743 | |
| Download: ML19317G682 (2) | |
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SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830, Sacramento, California 95813 (916) 452 -
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May 30, 1972
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Mr. R. W. Smith 5y2 Director, Region V C
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s Directorate of Regulatory Operations D'$* y ; $.f. %,
United States' Atomic Energy Commission
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2111 Bancroft Wayu
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Berkeley, California 94704
Dear Mr. Smith:
This is in reply to your letter of May 4,1972 in which you enclosed a list of nonconformances found during the AEC audits held March 9, March 20 through 24, and April 6,1972 relating to the construc-tion of the Rancho Seco Nuclear Generating Station. Our correents are as follows:
1.
Nonconforming material not properly segregated:
g Contrary to the AEC auditor's report, the specific pipe flanges which were tagged "Do Not Use for llN1" were not rejected material. These flanges were identified for the purpose of upgrading them to an llNL status and should have been segregated from other stock.
Since the audit, for purposes of documentation only, a Nonconformance Report was generated and dispositioned by proper authority to upgrade the reported flanges from Quality Class I to Nuclear (ASME Code classification) Class I by means of performing a liquid penetrant examination and reidentifying the flanges.
To avoid any possible confusion in the future, material-being held for upgrading will be identified with a " Hold" tag pending disposition of a Nonconformance Report and
-properly segregated.
2.
Indication that containment liner welds may not meet code requirements:
In recognition of the difficulty encountered when radiographs are read and interpreted without the benefit of visual exami-nation of both sides of the welds and without benefit of f(
initial examiner's reader sheets, the specific radiographs which were reviewed by your inspector have been re-reviewed, 8003 250 7f)
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N _,l Mr. R. W.-Smith May 30, 1972 both by the management inspector at the jobsite and by radio-l
' graphic experts from the Bechtel quality control and metallur-gical services group in San Francisco. Their review indicates,
that the welds do meet the code with the only exception being,
some minor variations from allowable porosity which have been reviewed by Engineering and determined acceptable. Based upon our evaluation, there were no indications of cracking,.non-fusion, or other propagating type defects.
It is important to point out that the principal function of these welds is to perform as a leak tight membranc and that the containment liner wolds have been 100% vacuum box tested for leak ~ tight in tegri ty.
The intended purpose of the endlos;rnphy was to provide an aid to quality control, and although it is not recognized as an effective method for examining welds to insure leak tightness, it has been' proven by. past experience to have a positive psychological ef fect on improving overall welding
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workmanship.
No further action is planned on this item.
Please advise us if these explanations are satisf actory.
sincerely yours,
. Mattimoe Assistant General Manager and Chief Engineer a
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