ML18153B034

Requests Response to NRC Request for Addl Info Re Molded Case Circuit Breakers,Within 45 Days of Ltr Date

ML18153B034
Person / Time
Site:	Surry, North Anna
Issue date:	08/05/1994
From:	Buckley B, Engle L Office of Nuclear Reactor Regulation
To:	Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
References
TAC-M88797, TAC-M88798, TAC-M88799, TAC-M88800, NUDOCS 9408110153
Download: ML18153B034 (4)

Text

' i Docket Nos. 50-280, 50-281 50-338, 50-339 Mr. J.P. O'Hanlon August 5, 1994 ~

Senior Vice President - Nuclear Virginia Electric and Power Company 5000 Dominion Blvd.

Glen Allen, Virginia 23060

SUBJECT:

SURRY AND NORTH ANNA POWER STATIONS, UNITS 1 AND 2 - MOLDED CASE CIRCUIT BREAKERS (TAC NOS. M88797, M88798, M88799, AND M88800)

The NRC staff is currently evaluating your submittal entitled, "The Analytical Assessment of Fault Current Interrupting Capability of As-Installed Configuration of 480V MCC Molded Case Circuit Breaker Only and Combination Molded Case Circuit Breaker Starter Units."

Based on our evaluation, we find that additional information, as delineated in Enclosure 1, is required to continue our review.

Please respond within 45 days of the date of this letter in order to expedite our review of your submittal.

This requirement affects fewer than 10 respondents and, therefore, it is not subject to Office of Management and Budget review under P.L.96-511.

(Original Signed By)

Leon B. Engle, Project Manager Project Directorate II-2 Sincerely, (Original Signed By)

Bart C. Buckley, Senior Project Manager Project Directorate Il-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation

Enclosure:

As stated cc.w/enclosure:

See next page OFFICE NAME DATE Distribution

• .Doc_~et _ _Fi 1 e*

NRC & Local PDRs PDII-2 RF SVarga GLainas VMcCree EDunnington BBuckley PM:PDll-2 LEngle LEngle OGC ACRS (10)

DVerelli, RII 9408110153 940805 PDR ADOCK 05000280 p

PDR

e Virginia Electric & Power Company cc:

Mr. William C. Porter, Jr.

County Administrator Louisa County P.O. Box 160 Louisa, Virginia 23093 Michael W. Maupin, Esq.

Hunton and Williams Riverfront Plaza, East Tower 951 E. Byrd Street Richmond, Virginia 23219 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation P.O. Box 1197 Richmond, Virginia 23209 Old Dominion Electric Cooperative 4201 Dominion Blvd.

Glen Allen, Virginia 23060 Mr. M. L. Bowling, Manager Nuclear Licensing & Programs Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Blvd.

Glen Allen, Virginia 23060 Office of the Attorney General Supreme Court Building 101 North 8th Street Richmond, Virginia 23219 Senior Resident Inspector North Anna Power Station U.S. Nuclear Regulatory Commission Route 2, Box 78 Mineral, Virginia 23117 Senior Resident Inspector Surry Power Station U.S. Nuclear Regulatory Commission 5850 Hog Island Road Surry, Virginia 23883 Robert B. Strobe, M.D., M.P.H.

State Health Commissioner Office of the Commissioner Virginia Department of Health P. 0.

• Box 2448 Richmond, Virginia 23218 Regional Administrator, RII U.S. Nuclear Regulatory Commission 101 Marietta Street, N.W, #2900 Atlanta, Georgia 30323 Mr. J. A. Stall, Manager North Anna Power Station P.O. Box 402 Mineral, Virginia 23117 Mr. J. P. O'Hanlon Senior Vice President - Nuclear Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Blvd.

Glen Allen, Virginia 23060 Mr. Michael R. Kansler, Manager Surry Power Station Post Office Box 315 Surry, Virginia 23883 Mr. Sherlock Holmes, Chairman Board of Supervisors of Surry County Surry County Courthouse Surry, Virginia 23683

~...

1 Request for Additional Information - Molded Case Circuit Breakers {MCCB)

North Anna Units 1 and 2

1.

Does the manufacturer support the use of the MCCBs in this manner?

Provide a copy of relevant correspondence between VEPCO and Kleckner Moeller regarding the use of the NZM6 and NZM9 MCCBs in applications which exceed their manufacturer's fault current rating. Additionally, provide the manufacturer information regarding the fault current rating for the Kleckner Moeller NZM6 and NZM9 MCCBs (1970-72 vintage).

2.

When assuming the worst case conditions for the fault current calculation, was it assumed that the emergency diesel generator (EOG) was operating in parallel with the grid as part of a load test? If so, what is the relative contribution to the fault current from the EOG?

3.

As part of the Appendix R, "Fire Hazard Analysis," it is required that systems needed for the safe shutdown of the plant be kept isolated from the fire hazard and remain in an operable condition.

Are any of the Kleckner Moeller NZM6 or NZM9 MCCBs credited for isolating equipment required for safe shutdown from a fire hazard? If so, are any of these breakers outside of their manufacturer's fault current rating?

4.

Are any of the Kleckner Moeller NZM6 or NZM9 MCCBs used as isolation devices between safety-related and non-safety-related equipment or as protection for containment penetrations? If so, are these breakers in applications which exceed their manufacturer's fault current rating?

5.

In addition to the above cases, identify the number of Kleckner Moeller NZM6 and NZM9 MCCBs that are used in safety-related applications?

6.

What has been North Anna's experience with electrical faults in the past?

Surry Unit 1 and 2

1.

Did the Surry staff contact the manufacturer of the FB and FA MCCBs regarding the ability of the breakers to interrupt currents outside their manufacturer fault current rating? If so, did the manufacturer support the use of the FA and FB MCCBs in this manner?

2.

When assuming the worst case conditions for the fault current calculation, was it assumed that the emergency diesel generator (EOG) was operating in parallel with grid as part of a load test? If so, what is the contribution to the fault current from the EOG?

3.

As part of the Appendix R, "Fire Hazard Analysis," it is required that systems, needed for the safe shutdown of the plant, be kept isolated from a fire hazard and remain in an operable condition. Are any of the

e Westinghouse FA and FB MCCBs credited as isolating equipment required for safe shutdown from a fire hazard? If so, are any of these breakers outside of their manufacturer's fault current rating?

4.

Are any of the Westinghouse FA and FB MCCBs used as isolation devices between safety-related and non-safety-related equipment or as protection for containment penetrations? If so, are these breakers in applications which exceed their manufacturer's fault current rating?

5.

In addition to the above cases, identify the number of Westinghouse FA and FB MCCBs that are used in safety-related applications?

6.

In the submittal, Surry included a UL fault circuit test document

1. 28-9672-1 for the FB and HFB MCCBs.

In this document the current for the test is listed as 25,020 Amps for the system.

Is this the current value for the source used in the test circuit or the current seen by the MCCBs under test?

7.

What has been Surry's experience with electrical faults in the past?