ML20212A572
| ML20212A572 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 02/17/1987 |
| From: | Hunsader S COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 2680K, NUDOCS 8703030374 | |
| Download: ML20212A572 (2) | |
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Address Reply to: Post Omco Box 767 Chice00. Illmoss 60600 0767 February 17, 1987 Mr. Harold R. Denton U.S. Nuclear Regulatory Connaission Office of Nuclear Reactor Regulations Washington, DC. 20555
Subject:
Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Appendix R Emergency Battery Pack Lighting NRC Docket Mos. 50-454. 50-455. 50-456 and 50-457
Dear Mr..Denton:
Appendix R to 10 CFR 50, Fire Protection program for operating nuclear plants, requires that emergency lighting units with at least an 8-hour battery power supply be provided in all areas required for operation of safe shutdown equipment and in access and egress routes thereto. At Byron and Braidwood, this requirement is fulfilled through the use of_Teledyne Big Beam battery pack lighting units. These battery pack lighting units, with internal hattery chargers, are currently designed to be powered from the AC essential lighting system throughout the plant. The battery pack lighting units are designed to turn on upon a loss of power supply to the internal battery charger.
Appendix R postulates that the worst case fire will be a fire which requires a shutdown of a Unit.
It also postulates that this shutdown will take place outside of the control room (ie, the control room has been evacuated) while the plant experiences a simultaneous loss of all offsite power. Under these circumstances, the Appendix R emergency battery pack lighting should energize and be available to assist the operators in their performance of emergency procedures.
At Byron and Braidwood, the battery pack lighting is powered from the AC essential lighting, and since the AC essential lighting is energized from an Essential Safety Feature (ESF) Motor Control Center (NCC), (which is fed from the diesel generator), the AC essential lighting will remain on and the required emergency battery pack lighting units will not turn on as required.
In order to alleviate this problem for the postulated scenario, we are implementing a design change which will remove the power feed for each of the Appendix R lighting units from the AC essential lighting and switch them to non-essential lighting fixtures, which are fed from non-safety related MCC's.
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.. For Braidwood Unit 1 Commonwealth Edison will complete the installation of the emergency battery pack lighting units prior to Initial Criticality. Installation and system demonstration testing of the associated rewiring work, as described above, will be completed prior to exceeding 5%
power. For Braidwood Unit 2 Commonwealth Edison will complete the installation of the emergency battery pack lighting units and the rewiring work prior to fuel load.
For Byron Unit #1, the design change will be implemented so that the physical work can be completed by September 1, 1987. For Byron Unit 2, CgCo will commit to complete the work on this design change by April 1, 1987.
As an interim measure, the Byron Operating Department will provide portable big beam battery powered lighting units for the uce of station operating personnel. Also, Byron and Braidwood Station personnel will be advised that should they be required to operate under the emergency fire conditions described above, that they can activate the permanent battery pack lighting units by simply unplugging them from their electrical outlet.
Unplugging the permanent battery pack lighting units from the essential lighting system will turn them on and will provide the operators with ample lighting for required emergency operations. These measures are summarized as appropriate for each station in daily orders that are available to operating personnel for their use. As such, no specific procedure changes are necessary.
please address any questions concerning this matter to this office.
One signed original and fif teen copies are provided for your review.
k S. C. Hunsader Nuclear Licensing Administrator
/klj cc:
L. 01shan J. Stevens 2680K
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