ML17056B558
| ML17056B558 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 10/23/1991 |
| From: | Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | Rosenthal J NRC |
| Shared Package | |
| ML17056B556 | List: |
| References | |
| NUDOCS 9112110308 | |
| Download: ML17056B558 (2) | |
Text
OCT 28 891 MEMORANDUM FOR:
FROM:
Jack E. Rosenthal, Leader Incident Investigation Team James M. Taylor Executive Director for Operations
SUBJECT:
NIN'E MILE POINT 2 INVESTIGATION TEAM FOLLONlP Although there was a general agreement between Niagara Mohawk comments and the incident investigation team report during the October 18, 1991 Commission
- meeting, one area of technical disagreement was identified that warrants resolution.
The incident investigation team determined that after the utility's design change transferred a.c.
input for the control logic power to inverter output rather than the phase B maintenance supply, the control logic batteries under certain circumstances continue to provide an important function during transfer of UPS power output from the inverter to the maintenance supply and hence improves overall system reliability.
The licensee's review concluded that the only function of the internal control logic batteries after the modification is to power logic lights for trouble shooting.
This distinction is important to identify the degree of maintenance and testing accorded this system at Nine Mile Point and possibly at other facilities with similar configurations.
r 9ii2ii0308 Viii27 PDR ADOCQ 050004i0j P
PDR Accordingly, I request that you, Frank Ashe and Tom Pohida with other support as necessary reexamine this technical area of disagreement during the week of October 28 thru November 1, 1991.
The reexamination should include review of supporting material collected during the investigation and discussions with technical experts from the licensee and the equipment vendor.
If further tests are necessary to verify equipment function adequate safeguards shall be applied to assure no perturbation of the operating unit.
This followup activity should be coordinated with NRR and Region I.
Original Signed By<
3atnes M.
Taylot'ames M. Taylor Executive Director for Operations cc:
SECY OGC ACRS GPA Reqional Administrators NRR Distribution AEOD R
F EDO R/F ELJordan DFRoss JMTaylor JHSniezek HThompson OFC: D: EOD: II
- DED:EDO: EDO NAME.
an enthal:JH iezek
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DATE:10@$91: jr:1@3 l91:10/ f/91
- 10/Pg/91 OFFICIAL RECORD COPY Document Name:
MEMO/ROSENTHAL
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