UNITED STATES ATOMIC ENERGY COMMISSION DIRECTORATE OF REGULATORY OPERATIONS REGION V P.O. BOX 1515 BERKELEY, CALIFORNIA 94701 January 10, 1974 Southern California Edison Company Docket No. 050-0206 P. O. Box 800 2244 Walnut Grove Avenue Rosemead, California 91770 Attention: Mr. Rollin E. Woodbury Vice President and General Counsel Gentlemen: The enclosed Directorate of Regulatory Operations' Information Request No. 74-1 is sent to you for response. Please submit your reply within thirty (30) days of the date of this letter to this office with a copy to the Assistant Director for Construction and Operation, Directorate of Regulatory Operations, U. S. Atomic Energy Commission, Washington, D. C. 20545. Sincerely, R. H. Engelken Director Enclosure: RO Information Request No. 74-1 8302220104 . Directorate of Regulatory Operations Information Request No. 74-1 ABNORMAL OCCURRENCES IN PIPING SYSTEMS The AEC has received notification of recent occurrences at the Indian Point 2 and San Onofre reactors which have resulted in damage to piping or piping hanger systems inside containment. Previously, reports of events resulting in unanticipated movement or damage to piping and hanger systems both inside and outside containment involving reactors of both PWR and BWR types have been received from licensees. These occurrences suggest that a pattern of events may be occurring which at individual facilities appear to be isolated events, but which in fact may have a common cause or causes and be generic in nature. It is possible that licensees have experienced other occurrences which may not have been of sufficient severity to have caused system damage, and may not have been considered reportable to the AEC under existing reporting requirements. To permit evaluation of these events for generic implications and the identification of possible common causes, information is requested regarding any event, condition, or malfunction or operating error which has been observed or experienced at your facility since plant startup relating to the following: 1. Anomalous and excessive vibrations of piping and/or components in Quality Group A and B systems as defined in Regulatory Guide No. 1.26. 2. Unanticipated pipe, component, or structural displacements, plastic deformations, or damage to Quality Group A or B pipe or component support systems. 3. Malfunctions of control systems or components which resulted in the imposition of unanticipated dynamic forces upon Quality Group A or B piping systems or components. With respect to each event identified above, the following information is requested: 1. The causes and operational sequences relevant to the condition or event. 2. The corrective actions taken, such as replacement or modification of malfunctioning components, or the addition or modification of piping system restraints, to prevent the recerrence of the event. . Information Request No. 74-1- 2 - In addition to the above items of interest there is another matter which may be related to events of the type under consideration. The AEC has learned of the existance at several PWR facilities of bulges in containment liners at locations adjacent to containment piping penetrations. To our knowledge these bulges have not affected containment integrity but their cause and significance are still being evaluated. To assist in further evaluation of this problem, please include in your responses to this request information on any containment liner bulges observed at your facility that exceed the limits accepted following construction.
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