ML19260D197
| ML19260D197 | |
| Person / Time | |
|---|---|
| Issue date: | 01/10/1980 |
| From: | Haass W Office of Nuclear Reactor Regulation |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8002080089 | |
| Download: ML19260D197 (2) | |
Text
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JAN 10 fc80
!ENORANDUM FOR: Darrell G. Eisenhut, Acting Director, Division of Operating Reactors FROM:
Walter P. Haass, Chief, Quality Assurance Branch Division of Project Management
SUBJECT:
POSSIBLE DEFICIENCY IN TESTING OF VITAL BUS TRANSFORERS It was recently brought to our attention by IE that scme applicants do not intend to perform full-load tests of vital 480 volt M buses using all sources of power supplies to the buses. As a result, s ee 4160-480 volt transfor= cts would not be full-load tested. Our concern is that if the transformers were not properly sized, a loss of voltage or a degraded voltage cociition on the vital buses during an accident could result. These applicants had comitted in their FSAR to Regulatory Guide 1.68 and did not take exception to the part which states that full-load tests of vital buses should be conducted using all sourt:es of power supplies to the buses. However, their test des-criptions (in FSAR Chapter 14) did not state explicitly that this testing would be conducted, and they maintained that their test progratu had been approved without full-load tests of these transfonners. It is possible that these same circumstances exist for scrne operating reactors, i.e., that some transfccmers supplying power to vital buses may not have been full-load tested during the initial test pogram.
It is our position that full-load tests of vital buses must be conducted includ-ing all sources of power supplies to the buses ((see enclosed staff position).
We are taking steps to ensure that such tests will be conducted at all facili-ties for which an OL has not been granted. It is our recceendation that 00R verify tht these tests have been (or will be) conducted at all operating power reactors.
Original signed DY waiter P. Haass Walter P. Haass, Chief Quality Assurance Brsnch Division of Project Managenent ec:
J. Higgins, RI DISTRIBUTION:
F. Rosa DSS scentral File 0Beckham S. Bryan,IE QAB Projects FAllenspach QAB Chron. File WHaass NRR Reading File BClayton DSkovholt QABpC.. ff o n, ice ).
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Staff Position It has ccrne to our attention that although some applicants had comitted to Regulatory Guide 1.68, they,did not intend to conduct full-load tests of some 4160-.180 volt transformers supplying power to vital buses. Your test description in FSAR Chapter 14 does not contain sufficient detail for us to determine if you planned to conduct such a test.
It is our position that full-load tests of vital buses must be conducted including all sources of pcwer supplies to the buses. Provide information that indicates whether this testing was conducted.
If this testing was not conducted, describe your plan for perfoming the testing, t