ML20102A699
| ML20102A699 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 07/20/1992 |
| From: | Shields J COMMONWEALTH EDISON CO. |
| To: | Charles Phillips, Siegel B NRC |
| References | |
| RTR-NUREG-0612, RTR-NUREG-612 NUDOCS 9207270224 | |
| Download: ML20102A699 (3) | |
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July 20,1992 Chuck Phillips clo Byron Siegel U.S. Nuclear Regulatory Commission Washington, D.C. 20555 MS 13D1
Dear Chuck:
On July 13,1992 we held a conference call to discuss the LaSalle Unit 1 Rerack Technical Specification amendment request. At that time, your staff had questions which required further clarification. Responses to their questions are attached.
Please call as further questions arise.
Sincerely, M
Jo nn Shields Nuclear Licensing Adminit,trator h
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Question: Please clarify statements found of pg 411 of me licensing report regarding residual gadolinium.
Response: Section 4.6 of the Licensing report demonstrates that as long as the enrichment and in-core k-infinity limits are met (4.6% and 1.332 respectively) the LaSa!1e Unit 1 racks can be utilized for BWR fuel storage without enticality safety concerns. Prior to placing any fuel in the new LaSalle Unit 1 racks, Commonwealth Edison will verify that the maximum k-infinity (at all burnups) and enrichments of the limiting lattice is less than the above specified limits.
The Licensing Report provided two k infinity limits, one including residual gadolinium and one without. Commonwealth Edison intends to utilize the in core k infinity limit that includes gadolinium (1.332), since standard reload lattice physics calculations typically retain gadolinium. The other k-infinity limit (1.355) is prov,ded for calculations with no rasidual gadolinium, and is included in the Licensing Report for information only.
Question: Please provide reference for the evaluation of the Reactor Building Crane for compliance to NUREG 0612.
Response: The Reactor Building overhead bridge crane is not single failure proof.
However, this crane has been designed to withstand seismic and tornado conditions.
The NRC review and acceptance of the LSCS Heavy Load Analysic, Phase 1, is documented in NUREG 0519, Supplement 5, Sections 9.1.2 and 9.1.3, dated August 1983. The NRC acceptance of the analysis provided for LaSalle County Station - Unit 2 Operating License Condition 2.C(14) " Control of Heavy Loads"is documented in a letter from A. Schwencer (NRC) to D.L. Farrar (CECO), dated March 12,1985.
Question: Does LaSalle County Station have the capability to supply fuel pool emergency make up water to the fuel pool directly from the cooling lake.
Response: Manual fire hose protection is provided near the spent fuel pools. Fire protection water (lake water) can be directed to the fuel pool to maintain level if necessary. The distribution of fire water through the system is provided for by diesel powered fire pumps.
Question: Page 9-8 of the Licensing Report includes an estimated exposure of less than 10 man-rem associated with activities necessary to support the installation of the Unit 1. racks. Also included is the actual total exposure by major activity recorded during the implementation of the Unit 2 rack installation. Please provide a similar breakdown by major activity for the proposed Unit 1 rerack and discuss how Unit 2 lessons learned are being incorporated into the Unit 1 effort.
Response: Exposure during the Unit 1 rerack is expected to be 5.1 man-rem for underwater operations,2.7 man-rem for packaging and.75 man-rem for installation.
These reductions in estimated man-rem are attributed to the following items / lessons learned incorporated from the Unit 2 rerack.
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Underwater operations: The Unit 2 racks were hydrotazed under water and wiped down at the surface, We are currently planning to suspend a tent over the pool area such that hydrolazing may be accomplished above the water surface which will increase the effectiveness of this activity resulting in a reduction of the amount of components that require hand wipedown. Less time will also be required to clean up the pool prior to the Unit i rerack job due to a pre-vacuuming completed in February 1992. A more efficient vacuum system is now being used at LaSalle County Station as opposed to the pump and bag filter system employed for Unit 2.
Packaging: The Unit 2 racks were disassembled and labeled to accommodate a reassembly if necessary. We are not contemplating this activity for Unit 1 resulting in a
. reduction of man-tem.
Installation: The Unit 2 racks required structural modificadon prior to installation and was accomplished on the refuel deck. The Unit 1 racks will not require fwd modification resulting in a reduction of man rem.
LaSalle County Station ha.c estimated that the total exoscted exposure to implement the Unit 1 reracking modifl:htion to be 8.55 man-rem and has established a job goal of 8.0 man-rem.
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