ML20044B762
| ML20044B762 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/26/1993 |
| From: | Alexion T Office of Nuclear Reactor Regulation |
| To: | Yelverton J ENTERGY OPERATIONS, INC. |
| References | |
| TAC-M82550, NUDOCS 9303030439 | |
| Download: ML20044B762 (4) | |
Text
_ __ - ____
February 26, 1993 Docket No. 50-368 Mr. Jerry W. Yelverton Vice President, Operations AN0 Entergy Operations, Inc.
Route 3 Box 137G Russellville, Arkansas 72801
Dear Mr. Yelverton:
SUBJECT:
REQUEST FM ADDITIONAL INFORMATION REGARDING COMPLIANCE WITH ELZ (RICAL CIRCUITRY ISOLATION REQUIREMENTS AT ARKANSAS NUCLEAR ONE, UNIT 2 (AN0-2) (TAC NO. M82550)
By letter dated June 18, 1992, the NRC staff requested that you reassess the existing coordination of the primary and secondary containment penetration overcurrent protective devices to assure that adequate protection is provided for the full range of overcurrent conditions (short-circuits and overloads) for the affected circuits and initiate appropriate actions if warranted.
Entergy Operations, Inc. responded by letter dated September 4, 1992.
The staff has reviewed the September 4, 1992, response and needs further clarification.
Enclosed is a request for additional information (RAI),
responses to which are needed for the resolution of the above issues.
We request your response within 60 days of receipt of this letter to enable the staff to complete its review in a timely manner. The reporting requirements contained in this letter affect fewer than ten respondents; therefore, Office of Management and Budget clearance is not required under Public Law 96-511.
Sincerely,
/S/
Thomas W. Alexion, Project Manager Project Directorate IV-1
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Division of Reactor Projects - III/IV/V i
Office of Nuclear Reactor Regulation cc w/ enclosure:
See next page j
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February 26, 1993 Docket No. 50-368 Mr. Jerry W. Yelverton Vice President, Operations AND Entergy Operations, Inc.
Route 3 Box 137G Russellville, Arkansas 72801
Dear Mr. Yelverton:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING COMPLIANCE WITH ELECTRICAL CIRCUITRY ISOLATION REQUIREMENTS AT ARKANSAS NUCLEAR ONE, UNIT 2 (AND-2) (TAC NO. M82550)
By letter dated June 18, 1992, the NRC staff requested that you reassess the existing coordination of the primary and secondary containment penetration overcurrent protective devices to assure that adequate protection is provided for the full range of overcurrent conditions (short-circuits and overloads) for the affected circuits and initiate appropriate actions if warranted.
Entergy Operations, Inc. responded by letter dated September 4, 1992.
The staff has reviewed the September 4, 1992, response and needs further clarification.
Enclosed is a request for additional information (RAI),
responses to which are needed for the resolution of the above issues.
We request your response within 60 days of receipt of this letter to enable the staff to complete its review in a timely manner. The reporting requirements contained in this letter affect fewer than ten respondents; therefore, Office of Management and Budget clearance is not required under Public Law 96-511.
Sincerely, 3
^
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x Thomas W. Alexion, Projec Manager Project Directorate IV-1 Division of Reactor Projects - III/IV/V Office of Nuclear Reactor Regulation cc w'anclosure:
See next page
1 Mr. Jerry W. Yelverton Entergy Operations, Inc.
Arkansas Nuclear One, Unit 2 CC:
Mr. Donald C. Hintz, President Mr. John R. McGaha and Chief Executive Officer Vice President, Operations Support Entergy Operations, Inc.
Entergy Operations, Inc.
P. O. Box 31995 P. O. Box 31995 Jackson, Mississippi 39286 Jackson, Mississippi 39286 Mr. Robert B. McGehee Mr. James. J. Fisicaro Wisa. Carter, Child & Caraway Director, Licensing P.
v.
Box 651 Entergy Operations, Inc.
Jackson, Mississippi 39205 Route 3 Box 137G Russellville, Arkansas 72801 Mr. Charles B. Brinkman, Manager Washington Nucloar Operations Mr. Nicholas S. Reynolds ABB Combustion Engineering Nuclear Power Winston & Strawn 12300 Twinbrook Parkway, Suite 330 1400 L Street, N.W.
Rockville, Maryland 20852 Washington, D.C.
20005-3502 Mr. Robert B. Borsum Admiral Kinnaird R. McKee, USN (Ret) 214 South Morris Street Licensing Representative Oxford, Maryland 21654 B&W Nuclear Technologies 1700 Rockville Pike, Suite 525 Rockville, Maryland 20852 Senior Resident Inspector U.S. Nuclear Regulatory Commission 1 Nuclear Plant Road Russellville, Arkansas 72801 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Honorable Joe W. Phillips County Judge of Pope County Pope County Courthouse Russellville, Arkansas 72801 Ms. Greta Dicus, Director Division of Radiation Control and Emergency Management Arkansas Department of Health 4815 West Markham Street Little Rock, Arkansas 72205-3867 l
ENCLOSURE RE0 VEST FOR ADDITIONAL INFORMATION ARKANSAS NUCLEAR ONE. UNIT 2 CONTAINMENT PENETRATION OVERCURRENT PROTECTION fTAC NO. M82550)
OUESTIONS
- 1. The staff has noted the following problems associated with Calculation 85-E-Oll8-01, "RB Penetration Overcurrent Protection Study", Revision 1 dated April 22, 1992:
In response to staff queries the licensee indicated that several graphs (denoted figures) which describe the overcurrent protection coordination do not have any applicability to circuits now installed in AND-2.
The conductor damage curve in the graphs of the calculation are drawn as straight lines which do not reflect damage limits for the sustained overload current region (i.e. lower current, longer time period).
The licensee indicated that during the development of the calculation, numerous fuse types of each ampere rating were evaluated and the type exhibiting the slowest tripping characteristic was used to develop the coordination graphs.
The fuse actually installed may not be shown on these coordination graphs.
The licensee needs to verify that the coordination graphs associated with the subject calculation reflect devices actually installed.
Please provide the staff with a revised calculation correcting the problems noted above so that an effective review can be made of the primary and secondary containment overcurrent protection.
2.
Please identify those figures of the revised calculation where the full range of overcurrent conditions (short circuits and overloads) are not covered by both a primary and secondary overcurrent protection device.
3.
For those figures identified in Item 2 above which are to be credited with thermal overload heater protection against sustained overload conditions please provide the penetration conductor ampacity or rating as well as the information cited in Table 1 of the September 4,1992 submittal by the licensee.
4.
Please identify for those circuits associated with the figures cited in Item 2 above those design limitations and other rationale why overcurrent protection coordination cannot be improved for overload conditions.
Please note also the technical basis for the safety assessment that the hazard from sustained overload conditions is insignificant.