2CAN119402, Clarifies Util Intention to Not Install Replacement Breakers in Next Practical Refueling Outage for ANO Unit 2, Per Concern Raised Re Circuitry Isolation During Electrical Distribution Sys Functional Insp of Facility
| ML20076M457 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 11/02/1994 |
| From: | Mims D ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 2CAN119402, NUDOCS 9411070299 | |
| Download: ML20076M457 (2) | |
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Te 501-964-3100 November 2,1994 2CAN119402 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station PI-137 Washington, DC 20555
Subject:
Arkansas Nuclear One - Unit 2 Docket No. 50-368 License No. NPF-6 Electrical Circuitry Isolation Requirements Gentlemen:
During the electrical distribution system functional inspection (EDSFI) conducted for Arkansas Nuclear One, Unit 2 (ANO-2), a concern was raised regarding circuitry isolation. The NRC requested Entergy Operations to reassess the existing coordination of the primary and secondary containment penetration overcurrent protective devices to assure that adequate protection was provided for the full range of overcurrent conditions (short-circuits and overloads) for the affected circuits.
In response to the NRC's request, Entergy Operations submitted a letter to the N'RC dated September 4,1992 (0CAN099202). This letter stated, in part, that eleven replacement breakers would be installed in the next practical refueling outage for ANO-2 in an efrort to improve the overcurrent protection on identified circuite by providing enhanced breaker coordination in the overload region of the penetration conductor damage curves.
Following the September 4, 1992 submittal, an evaluation was performed which determined that the breaker replacements were not necessary. The purpose of this letter is to ensure that the information on the docket is clear regarding ANO's intention to not install the replacement breakers.
The letter which accurately reflects ANO's commitment to resolve this issue is ANO's letter to the NRC dated April 30,1993 (OCAN049305). In this letter, ANO committed to revise the Unit 2 penetration study to include consideration of penetration circuit faults in the overload region. The revised study was submitted to the NRC on August 20,1993 (0CAN089304). The revised study determined that all penetrations were protected in the 070044
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9411070299 941102 i 3 PDR ADOCK 05000368
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U. S. NRC November 2,1994 io 2CANI19402 Page 2 l
overload fault current region by at least one protective device. This determination negates j
the need to change any circuit breakers.
I The NRC responded to our April 30,1993, correspondence in a letter dated February 23, 1994 (0CNA029402), which concluded that no further action on our part was necessary at this time. The NRC indicated that they may still have differing opinions with ANO regarding the requirements of ANO's licensing basis and the interpretation of the regulatory guidance. The letter further stated that the NRC was pursuing the matter l
generically, but that ANO's current position was acceptable.
l ANO intends to stay abreast of industry and regulatory developments regarding this matter and will take appropriate actions as necessary. Should you have questions or comments, please contact me.
Very truly yours,
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Dwight C. Mims l
Director, Licensing DCM/dwb cc:
Mr. Leonard J. Callan J
Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 NRC Senior Resident Inspector Arkansas Nuclear One 1448 S. R. 333 Russellville, AR72801 Mr. George Kalman NRR Project Manager Region IV/ANO-1 & 2 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-H-3 l
One White Flint North 11555 Rockville Pike Rockville, MD 20852 l
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