ML19319C433
| ML19319C433 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 08/30/1977 |
| From: | Engle L Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8002140813 | |
| Download: ML19319C433 (4) | |
Text
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8 AUG 3 01977 DCCXET NO: 50-346 LICENSEE:
Toledo Edison Company FACILITY:
Davis Besse fluclear Power Station, Unit 1
SUBJECT:
SUMMARY
OF MEETI'IG HELD ON AUGUST 17, 1977 ON STATICN INSTRUMENT GROUND GRID TEST Backaround and Succary A meeting was held on August 17, 1977 with the Toledo Edison Ccmpany regarding their request to proceed to Operational Mode 1 ( 5% to full power) at Davis Besse. Unit I withcut further testing or corrective actions on the facility Instrument-Station Ground Grid System. An attendance list is attached.
In a letter from L. Roe (Toledo Edison Company) to J. Xccpler (I&E, Region 3) dated August 7,1977, the Toledo Edison Company identified all of the systems that have the station ground and instrument ground connected (i.e., Reactor Protection System, Nuclear Instrumentation, Station-Computer, Integrated Control System Control Rod Drive System and the non-essential Miscellaneous Electrical Control System) and are Babcock and '.411cox (B&W) or Bailey supplied eauipment.
The Toledo Edison Company stated that based upon the results of ground grid tests presently completed, it acpears that the systems as noted above have an unkncwn number of inadvertent ties between the instrument and station grounds instead of the facility design objective for a single tie between the instrument ground and the station ground. The Toledo Edison Company further stated that although their design objective had not been achieved, the end product of the presently installed system was no different than other facilities which use a single station ground system.
A discussion followed regarding potential electrically faulted facility conditions with the ground system as presently installed which could pemit current loops through the instrument and station ground grid systems. The NRC staff inquired and received no assurance that the B&W or Bailey equipment was designed to operate acceptably with the present facility station ground system.
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4 3 0 1977 The Toledo Edison Company stated that they did not wish to proceed further with identifying the sources of station to instrument ground.
ties because they had not experienced any adverse effects or malfunc-tions of the instrument and control systems during facility hot functional tests and subsequent facility operation through Mode 3.
The Toledo Edison Company also indicated that they were constrained by the Technical Specifications regarding the operability of the Reactor Protection System to perform any troubleshooting and corres-pending corrective actions involving that system.
In conclusion, the staff :ated to the Toledo Edison Company, that based upon the infomation provided so far, the staff could not conclude at this time that Davis Besse, Unit 1, could operate safely in Mode 1 with the then presently installed in3trument-station ground grid system. The staff stated to the Toledo Edison Company that they would review this matter quickly and advise the Toledo Edison Company on any additional actions required to resolve this matter.
Cri inal si: ed by 8
Leon 3. Engle i
Leon Engle, Project !ianager Light Water Raactors Branch No. 1 Division of Project Manacement
Enclosure:
List of Attendees OPM: LWR #h DPM:L % #1 summaus >, LEngb,.Q
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NRC P9RM 318 (9 76) NROC 02e9,
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L 3-30 577 Toledo Edison Company cc: Mr. Conald H. Hauser. Esq.
The Cleveland Electric Illuminating Company P. O. Box 5000 Cleveland, Ohio 44101 Gerald Charnoff, Esq.
Shaw, Pittman, Potts and Trowbridge 1800 H Street, N. H.
Washington, D. C.
20036 Leslie Henry Esq.
Fuller, Seney. Henry and Hedge 300 Madison Avenue Toledo, Ohio 43604
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