ML042080347
| ML042080347 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 10/31/2003 |
| From: | Morrissette R Vermont Yankee |
| To: | Office of Nuclear Reactor Regulation, Vermont Yankee |
| References | |
| FOIA/PA-2004-0267 | |
| Download: ML042080347 (2) | |
Text
Sienel, Beth From:
Morrissette, Remi Sent:
Friday, October 31, 2003 8:46 AM To:
VTY - Plant
Subject:
This memo applies only to personnel who work in the RCA Attached is a memo on the potential increase in dose rates in the plant from the injection of hydrogen into the feedwater system which is scheduled to commence on 11/7/03 around 2200. If you have any questions concerning this matter please call me at Ext. 5472 Hydrogen Injection.doc (1 MB)
Thanks, Remi ALARA Engineer 1
. emo To:
Plant Staff From:
Remi Morrissette Date:
6/15/2004 Re:
Elevated dose rates due to the addition of Hydrogen On November 8th, we will start to inject hydrogen into the feedwater system. This process in conjunction with the noble metals application prevents cracking in the Reactor Vessel. Therefore, we will see an increase in transport of N-16 (a high-energy gamma ray emitter) into the STEAM flow path. The highest dose rate increases will be in the steam-affected areas of the plant such as the Turbine Building Heater Bay. We expect about a 20% increase in dose rates, which is significantly lower than the increases we experienced as a result of the noble metals application. Fortunately, these areas are rarely accessed while at power and should contribute little to site doses. Several accessible areas in the plant will also have higher than normal dose rates. Specifically, the turbine deck and its surrounding areas, such as the TB HVAC rooms, the old l&C shop, the turbine viewing gallery, and the adjoining second floor offices of the administration building.
During hydrogen injection, RP will be monitoring for changing dose rates and we will post areas to inform entrants of the risk.
We expect dose rates to return to normal levels within a month to two months.
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