ML19270H476

Forwards Request for Addl Info to Be Sent to Licensee in Order to Complete Review of 770722 Submittal Re Technical Assistance Contract 10026.Response Required within 45 Days

ML19270H476
Person / Time
Site:	Hatch
Issue date:	07/23/1979
From:	Lainas G Office of Nuclear Reactor Regulation
To:	Ippolito T Office of Nuclear Reactor Regulation
References
TAC-10026, TAC-11262, TAC-12831, TAC-47044, NUDOCS 7908270482
Download: ML19270H476 (3)

Text

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MEMORANDUM FOR:

T. Ippolito, Chief, Operating Reactors Branch #3, Division of Operating Reactors FROM:

G. Lainas, Chief, Plant Systems Branch, Division of Operating Reactors

SUBJECT:

EDWIN I. HATCH UNIT 1, REQUEST FOR ADDITIONAL INFORMATION DEGRADED GRID VOLTAGE (TAC 10026)

Plant Name:

Edwin I. Hatch, Unit 1 Docket No.:

50-321 Responsible Branch: ORB #3 Project Manager:

D. Verre111 Reviewing Branch:

Plant Systems Branch Status: Awaiting Information In response to technical assistance request TAC 10026, the Plant Systems Branch has reviewed the licensee's submittal of July 22, 1977 and found that additional information is required in order to complete our review.

The attached request for additional infonnation should be forwarded to the licensee as soon as possible with a request for response within 45 days.

dc v G'. L'ainas, Chief Plant Systems Branch Division of Operating Reactors

Contact:

S. Rhow, X28077 C. Cleveland, EG&G

Enclosure:

As rtated 7908 2 704 W

nacAC)e

. cc w/ enclosure:

D. Eisenhut W. Gamill B. Grimes D. Verrelli G. Lainas D. Tondi M. Chiramal P. Shemanski S. Rhow C. Cleveland, EG&G

9 REQUEST FOR ADDITIONAL INFORMATION EDWIN I. HATCH NUCLEAR PLANT UNIT 1 DEGRADED GRID VOLTAGE (TAC 10026) 1.

The NRC letter of June 2,1977, position (1)(f) called for surveillance requirements for second level undervoltage monitors.

Enclousre 2 of that letter orovided Model Technical Specifications (MTS) to be followed as closely as possible. Modify your pro-posal to include a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> channel check for these monitors.

2.

In your submitted proposal for surveillance requirement 4.9. A.6.C, the load breakers are in test position.

Your proposal also does not mention the > 5 minute requirement of the MTS.

It is the staff's position 7 as shown in Enclosure 2, 4.8.1.1.X.C, that the time requirement and actual loading of the buses should be performed.

These tests will confirm that the voltage transients from starting large motors will not trip the emergency buses spuriously.

Comply with this criteria or provide additional justification to support your present submittal.

3.

Provide sufficient information (voltage drop analyses) to allow our independent verification that the undervoltage protection voltage setpoint and time delay selected will not cause spurious separation of safety buses from offsite power during all modes of plant operation (start-up, shutdown, power operation and accident condition) due to automatic or manual starting of large motors, bulk or sequential loading or automatic transfer of electrical loads.

The analyses should include conditions when the safety buses are supplied power from the Unit Auxiliary Transformer, the start-up/ reserve transformer or other available offsite connections and assuming the need for electrical power is initiated by an anticipated transient (e.g., unit trip) or an accident, whichever presents the largest load demand.

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