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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