Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
GL79015
UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON, D.C. 20555
March 21, 1979
ALL PRESSURIZED WATER REACTOR LICENSEES
Gentlemen:
This letter is being sent to all licensees authorized to operate or
construct a pressurized water power reactor and to all applicants for a
license to operate or construct a pressurized water power reactor.
Operating problems have occurred in Pressurized Water Reactor (PWR) steam
generators. The enclosed report, "Summary of Operating Experience with
Recirculating Steam Generators," NUREG 0523, focuses on the problems
associated with steam generators of the recirculation type, i.e., those
manufactured by Combustion Engineering and Westinghouse. The report
discusses the NRC staff's evaluation of these problems and the programs for
resolving these problems.
The NRC has recently identified steam generator degradation as an Unresolved
Safety Issue deserving the highest priority for resolution. However, for the
reasons identified in the report, the NRC staff has concluded that continued
operation of existing plants and licensing of new plants with recirculation
type steam generators, pending completion of our review, does not constitute
an undue risk to the health and safety of the public and therefore may
continue.
It should be noted that a number of research efforts are currently under way
which will improve our knowledge of steam generator our current
understanding of each issue. Comments on this report and information
.
- 2 - March 21, 1979
related to steam generator degradation mechanisms are encouraged and should
be forwarded to Dr. Boen-Dar Liaw, Engineering Branch, Division of Operating
Reactors, U. S. Nuclear Regulatory Commission, Washington, D.C. 20555.
D. G. Eisenhut, Deputy Director
Division of Operating Reactors
Enclosure:
Summary of Operating Experience
with Recirculating Steam
Generators, January 1979,
NUREG 0523
cc w/o enclosure:
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