IE Circular No. 79-11 - Design/Construction Interface Problem
CR79011 June 21, 1979 MEMORANDUM FOR: B. H. Grier, Director, Region I J. P. O'Reilly, Director, Region II J. G. Keppler, Director, Region III K. V. Seyfrit, Director, Region IV R. H. Engelken, Director, Region V FROM: Harold D. Thornburg, Director, Division of Reactor Construction Inspection, IE SUBJECT: IE CIRCULAR NO. 79-11 - DESIGN/CONSTRUCTION INTERFACE PROBLEM The subject circular should be dispatched for action to all applicants for, and holders of power reactor construction permits no later than June 27, 1979. The text of the circular and draft letter to licensees are enclosed for this purpose. Harold D. Thornburg, Director Division of Reactor Construction Inspection Office of Inspection and Enforcement Enclosures: 1. Draft Transmittal Letter 2. IE Circular No. 79-11 CONTACT: W. Laudan, IE 49-27551 . (Draft letter to all applicants for, and holders of construction permits) IE Circular No. 79-11 Gentlemen: The enclosed Circular 79-11, is forwarded to you for information. No written response to this Circular is required. If you require additional information regarding this subject, please contact this office. Sincerely, Signature (Regional Director) Enclosures: 1. IE Circular No. 79-11 2. List of IE Circulars Issued in the Last 12 Months . UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 June 27, 1979 IE Circular No. 79-11 DESIGN/CONSTRUCTION INTERFACE PROBLEM Description of Circumstances: Apparent inadequate communication 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 misorientation problems 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 relationships 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 information into site construction documents, the A/E may make changes to facilitate construction of the balance of plant. These translations may also introduce errors which may not be . IE Circular No. 79 - 11 June 27, 1979 Page 2 of 2 recognized as errors by the A/E's review system. The organization responsible for function and/or structural design must be made aware of changes affecting design and operating 'parameters so that proper evaluation is performed. It is recognized that there are effective field construction inspection systems, deficiency reporting systems and as-built check systems to uncover and correct for deviations from design. However, these are reactive type systems that address the problems after the errors occur and that rely on detection of errors and design deviations in the construction phase. The detection of certain other errors and design deviations may only be recognizable at the design level. The NRC's concern is that in some instances sufficient checks at the design level are not being performed to preclude design errors discovered at the construction site and that the designer may not be aware of other design related changes that affect design and operating parameters. The 10 CFR 50, Appendix B requirement that addresses this concern is contained in Criteria III which states in part: "Measures shall be established for the identification and control of design interfaces and for coordination among participating design organizations. These measures shall include the establishment of procedures among participating design organizations for the review, approval, release, distribution, and revision of documents involving design interfaces." Preventive action at the design level is necessary to minimize the possibility of the appropriate parties not being aware of A/E and construction related design changes and to prevent errors from occurring. An appropriate preventive action would be to have the NSSS review A/E drawings that show the location, orientation, clearance, etc., for equipment that the NSSS has functional and/or structural design responsibility. All holders of construction permits should be aware of the potential problems caused by inadequate communication between the design organization and the construction organization and should take appropriate action to assure themselves that adequate interface controls are established and implemented. No written response to this circular is required. If you require additional information regarding this matter, contact the Director of the appropriate NRC Regional Office.
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