United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for August 12, 1999

                       Headquarters Daily Report

                         AUGUST 12, 1999

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                    REPORT             NEGATIVE            NO INPUT
                    ATTACHED           INPUT RECEIVED      RECEIVED

HEADQUARTERS        X
REGION I                               X
REGION II                              X
REGION III                             X
REGION IV                              X
PRIORITY ATTENTION REQUIRED  MORNING REPORT - HEADQUARTERS AUGUST 12, 1999

Licensee/Facility:                     Notification:

Nebraska Public Power District         MR Number: H-99-0071
Cooper 1                               Date: 08/12/99
Brownville,Nebraska
Dockets: 50-298
BWR/GE-4

Subject: Safety Related Battery Cell Degradation

Discussion:

The licensee for the Cooper Nuclear Station has found degradation in
several cells in their 125-volt safety related batteries. The batteries
were manufactured by C&D Power Systems. The batteries were purchased
commercial grade and dedicated by a third party. The batteries were
installed in the plant 5 to 7 years ago. The initial indication of a
problem was a lower than expected voltage on several cells during
surveillance testing. An inspection of these cells revealed excessive
growth of the positive plates. The growth was such that the positive
plates appeared to have made contact with the negative plate support
structure at the top of the cells. Abnormal growth was subsequently found
in the positive plates of other battery cells. The licensee intends to
replace a total of ten cells that were found degraded. C&D Power Systems
attributed the abnormal plate growth to excessive calcium in the plate
material. The vendor concluded that the calcium content in the plate was
not properly controlled during plate manufacture. The plates contained
two to five times the specified amount of calcium.

Contact:  C. Petrone                 (301)415-1027
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