ML20236W259
| ML20236W259 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 10/26/1987 |
| From: | Ainger K COMMONWEALTH EDISON CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 3707K, NUDOCS 8712070360 | |
| Download: ML20236W259 (2) | |
Text
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[~'h) Commonwealth Edinon
/
One First N2ional Plaza, Chicago, Illinois
(
~~ "7 Address R, ply to: Post Offic) Box 767
(,,/
Chicago, Illinois 60690 - 0767 October 26, 1987 j
Mr. A. Bert Davis Regional Administrator U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137
Subject:
Byron Station Unit 1 NRC Inspection Steport No. 50-454/87-026 NRC Docket No. 50-454
Dear Mr. Davis:
This is in response to a request by Mr. G. Wright of your staff to provide additional information concerning our response of August 21, 1987 to NRC Inspection Report No. 50-454/87-026.
Mr. Wright requested that we:
(1) elaborate on the reasons the spent fuel pool level could not be restored to its normal level by makeup from alternative water sources besides the chemical and volume control system and (2) discuss our plans to implement Sargent & Lundy recommendations regarding fuel handling operations described in a letter to Commonwealth Edison dated December 19, 1985.
Spent Fuel pool Level Makeup Section 9.1.3.2 of the FSAR describes methods for increasing the water inventory in the spent fuel pool.
It discusses the initial fill using a permanent connection f:om the refueling water storage tank to the spent fuel rool, or a temporary line from the boric acid blender to the spent fuel pool. It also discusses the use of a demineralized water source for makeup purposes.
The Unit I refueling water storage tank was dismissed from consideration for makeup purposes.
Throughout refueling operation, it was at an approximate level of 15%. The Technical Specifications allow the level to be reduced to 9% during Mode 6 operations.
It was decided, however, that 15% was required for accurate ASME pump surveillance testing which was scheduled throughout the outage.
The boric acid blender was also excluded from consideration for makeup purposes. Although the temporary line connecting the boric acid blender to the spent fuel pool was in place, it could not be used. The temporary line was in place to facilitate the initial fill of the spent fuel pool. It should be noted that this method of spent fuel pool makeup is not l
routinely available. Once the pool was full, the boric acid blender was l
removed from service as an isolation point to support a scheduled l
modification to the ICV 110A valve. The out-of-service made this source of I
borated water unavailable to the spent fuel pool.
f 8712070360 871026 0@ 25 j
PDR ADOCK 05000454 I
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. A. B. Davis October 26, 1987 The demineralized water source referenced in the FSAR is the primary water system.
Its principal makeup function is to replace evaporative losses. The use of this system for level losses other than evaporative would create the potential for a dilution of the spent fuel pool below the Technical Specification required boron concentration. Therefore, this system was dismissed for makeup purposes.
Although available, the Unit 2 boric acid blender was dismissed for makeup purposes. The temporary hose needed to carry borated water from the blender to the spent fuel pool was not in place. Also, the Unit 2 blender was in service supporting operation of the Unit 2 reactor which was critical.
Although the Unit 2 RWST was available, it was dismissed as a non-emergency source for makeup. A large reduction in volume of the Unit 2 RWST would have caused a potential violation of its Technical Specifications. However, had an uncontrolled loss of level in the spent fuel pool existed, this source of makeup could have been used to mitigate the consequences of an accident as outlined in 2 BOA REFUEL-3.
Sargent & Lundy Recommendations A number of the recommendations have been or will be implemented.
1.
The minimum water level has been set at 424'-2".
2.
The bottom of the fuel assembly elevation has been set at 401'-10".
3.
The top of the fuel assembly will be defined in Amendment 49 of the FSAR.
l 4.
There is a local indicator (ruler) which has been installed. This ruler l
was in place during Unit 1 refueling.
I 5.
A modification request has been submitted to our engineering department to modify the fuel handling tool racks in the fuel handling building such that the tool handle will remain above the water level.
All.the items concerning the cask pit wl'l be evaluated prior to l
the shipment of an irradiated fuel assembly, byron Station reviewed the additional items for improving shielding and. applied these recommendations, as applicable.
please direct any further questions regarding this matter to this office.
l l
Very truly yours, e-P K. A. Ainger Nuclear Licensing Administrator cc: Byron Resident Inspector G. Wright - RIII 3707K L_________-_
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