ML19261E261
| ML19261E261 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 06/27/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Bryan J UNION ELECTRIC CO. |
| References | |
| NUDOCS 7907050481 | |
| Download: ML19261E261 (1) | |
Text
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NUCLEAR REGULATORY COMMISSION 3, M!)b[c$'
REGION lli o,
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'N-GLEN ELLYN, ILLINOIS 60137
,p JUN 2 71979 Docket No. 50-483 Docket No. 50-486 Union Electric Company ATTN:
Mr. John K. Bryan Vice President - Nuclear P. O. Box 149 St. Louis, MO 63166 Gentlemen:
The enclosed Circular No. 79-11, is forwarded to you for informat4 on.
No written response to this Circular is required.
If you require additional information regarding this subject, please contact this office.
Sincerely, l'
du lu. f \\)c' s j' t
ames G. Keppler
/ Director
Enclosure:
IE Circular No. 79-11 cc w/ enc 1:
Mr. W. H. Weber, Manager, Nuclear Construction Central Files Director, NRR/DPM Director, h3R/ DOR PDR Local PDR NSIC TIC Region I & IV Ms. K. Drey Hon. C. J. Frass, Chairman Missouri Public Service Commission
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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT REGION III June 27, 1979 IE Circular No. 79-11 DESIGN / CONSTRUCTION INTERFACE PROBLEM Description of Circumstances:
Apparent inadequate com=unication between nuclear steam supply system (NSSS),
architect / engineer (A/E) and constructors have resulted in several cases where reactor vessels or the supports have been misoriented. The misorienta-tion proble=s appear to occur at sites where dual reactor units are being constructed and one primary system layout is a mirror image of the other.
In 1975 TVA reported a misorientation problem with the Sequoyah Unit 2 reactor vessel.
Westinghouse was the NSSS supplier and TVA provided their own A/E service.
In 1977 the Southern California Edison Company reported a reactor vessel misorientation at San Onofre Unit 2.
Combustion Engineering was the NSSS supplier and Bechtel provided the A/E service.
In 1979 the Texas Utilities Generating Company reported a reactor vessel support system misorientation at Comanche Peak Unit 2.
Westinghouse supplied the NSSS, Gibbs and Hill was the plant engineer and Brown and Root was the constructor.
Even though there appears to be minimal safety implications associated with the particular misorientation problems mentioned, repetition of the same type of errors suggests breakdowns in the design / construction interface relation-ships that could in turn lead to more significant safety problems.
Corrective preventive action is recommended for the following reasons:
If the interface control system between the NSSS/AE/ Construction is marginal or ineffective as evidenced by the misorientation of reactor vessels and their supports, it is possible that other safety related equipment may also be misoriented and/or mislocated.
In some cases the errors may not be as obvious as a misoriented reactor vessel.
This type of error can and has resulted in hardware modifications and could cause functional and/or structural changes that affect design and operating parameters.
In translating NSSS design infor9 DUPLICATE DOCUMENT
_.-mm the A/E may make changes to facil plant.
These translatione may a]
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