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JUL 181984 MEMORANDUM FOR: Gus C. Lainas Assistant Director for Operating Reactors.
Division of Licensing FROM:
L. S. Rubenstein, Assistant Director for Core and Plant Systems, Division of Systems Integration
SUBJECT:
AUXILIARY FEEDWATER SYSTEM - POWER DIVERSITY REQUIREMENTS-DAVIS BESSE By memorandum of August 29, 1983 the Auxiliary Systems Branch (ASB) provided its safety evaluation repert for TMI Task Action Plan Item II.E.1.1, " Auxiliary Feedwater System" for the Davis Besse auxiliary feedwater system (AFWS) with qualifications:
1.
In three cases it was stated that-the staff will require the licensee to provide acceptable comitments to meet stated staff positions, and 2.
A CRGR package was being prepared which would require certain operating plants, including Davis Besse, to upgrade their AFWS to meet the existing system reliability and power diversity requirements of SRP Section 10.4.9.
Additionally by memorandum of November 16, 1983 we notified you that we have reviewed tne Davis Besse AFWS reliability study and concluded that the design was in the low unreliabjlity range and its reliability did not meet the numerical criterion of 10' to 10-5 failure probability per demand required by the SRP.
We' also stated in this memorandum that the lack of diversity in the AFW pump drive causes the Davis Besse AFWS to be particularly susceptible to potential common cause failures.
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Regarding Item 1 of our SER it is ASB's understanding that the licensee is preparing comitments which we believe will be acceptable to the staff.
Regarding the second item, preparation of the CRGR package to require all operating plants to meet existing AFWS reliability and power diversity requirements, this item has been sufficiently delayed so that we believe a special dialogue should be begun with Davis Besse on their lack of AFWS power diversity.
The only other operating plant without a diverse drive AFW pump was Turkey Point 3 & 4.
We have been informed, however, that FP&L has procured motor driven pumps which may by now be installed.
In addition shortly after the TMI-2 accident, the Tedesco Report, NUREG-0667, " Transient Responses of Babcock and Wilcox-Designed Reactors" reccmended that " installation of a diverse-drive AFW pump should be expedited at the Davis Besse 1 facility." More recently I&E and the ACRS have approached ASB requesting the status of the branch's resolution of the Davis Besse diverse drive AFW pump issue.
Contact:
- 0. Parr
.AM X27483 4 725@L35 PP
.o s
JUL 181984
' We believe that it is prudent to meet with the Davis Besse licensee at this t.ime to discuss the diversity question without waiting for completion of the CRGR package. We therefore request that you arrange such a meeting in the near future.
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'h L. S. R nstein, Assistant Director for Core and Plant Systems Division of Systems Integration ec: Director, DSI
- 0. Parr J. Wilson J. Ridgely
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A. DeAgazio J. Stolz
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