ML20066C097
| ML20066C097 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 01/02/1991 |
| From: | Morgan W COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| ZNLD654-10, NUDOCS 9101090238 | |
| Download: ML20066C097 (3) | |
Text
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h Ctmmtnwealth Edistn
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January 2,1991 U.S. Nuclear Regulatory Commission 1
Attn: Document Control Desk Washington, D.C. 20555
Subject:
LaSalle County Station Units 1 and 2 Response to Request for Additional Information Concerning Proposed Amendment to the Technical Specification for Facility O3erating License NPF-11 and NPF 18 N 9C DDChet Nos._50 373 andEQ:324 W.E. Morgan letter to T.E. Murley dated-(a) July 26,1989.
References:
(b) W.E. Morgan letter to U.S. NRC dated July 9,1990.
Dear Sir:
References (a) and (b) transmitted Commonwealth Edison's proposed Technical Specification Amendment to allow continued plant operation for a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> with the Main Steam Tunnel High Ambient Temperature and High Ventilation Systems Differential Temperature Trips Bypassed, The following attachment provides Commonwealth Edison's LaSalle Station response to the NRC question concerning the expected radiation dose rates in the Unit 1 and 2 Main Steam Tunnels during power operation.
Please direct any questions you may have regarding this matter to'this office.-
j Very truly yours, vt b W.E. Morgan Nuclear-Licensing A_ dministrator Attachment cc: J. Hickman - Project Manager, NRR Senior Resident inspector
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AUACHMENI NBC_ Question:
What is the radiation dose rate in the Units 1 and 2 Main Steam Tunnel's (MST) during power operation?
S_tattolLBespsos_e:
During the Unit 2 Startup Test Program in 1984 a survey of the MST dose rates at various power levels was completed by the station Radiation Protection Department.
The dose rates in the MST are due almost entirely to N16 gamma rays. Since, the level of N16 present in the steam in a BWR is a function of reactor power, it can be assumed that this data may also be applied to Unit 1. The data Indicates that the dose rate varies directly with power from less than 50 mrem / hour at 100 MWe to?
1200 mrem / hour at 1080 MWe (refer to the attached graph of Dose Rate vs. Power).
As can be seen from the data provided, it can be ex aected that any entries made into the MST while the reactor is at high power, will resu t in significant man rem accumulations for plant aersonnel, it should also be noted that during the period of time that the reactor bul ding ventilation system is shutdown it is anticipated that the MST tunnel temperatures will exceed 150 F, These elevated temperatures will help to create a hostile work environment in the MST that will add to the danger of performing periodic inspections.
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LaSalle County Station Unit 2 Main Steam Tunnel Dose Rate vs Power Dose Rate (mrem /Hr) l 1400 1200-
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200 400 600 800 1000 1200 Generator Output (MwE)
Data From 1984
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