Containment High Range Area Monitors

[Sung Jun Maeng <sjmaeng@kepri.re.kr>]

Dear Radsafers,


Is there any one out there in RADSAFE area who have experiences in
calculating alarm set point
for radiation monitoring systems in nuclear power plants.
 
I am intersted in calculation of alram setpoint for "containment high range
area monitors"
which I think were forced to be installed for monitoring any accident
conditions in containment 
after TMI accident as one of the action items  
In general they are able to measure gamma dose rate upto 10E6 R/h.
If dose rate reaches the alarm setpoint value, it gives containment purge
and exhaust isolation signal.
So it is pretty important to determine the setpoint value in terms of the
safety operation and public safety. 

I am thinking of several criteria which can be applied to setting the alram
value.
 
  1) 10CFR 20 limit
     I am afraid that this could gives too low value. 
     Do you think this would be appropriate in terms of its high detection
range?
  2) 10CFR100 limit

Setpoint values for purge isolation signal are described in technical
specifications
(Engineered Safety Feature Actuation System) in a final safety analysis report.
I wonder if there are NRC's position papers or guidelines published for
utilities.


I would appreciate sharing your experiences and knowledge.      

Please repond to me directly.    


Thank you


Sung-Jun Maeng
Korea Electric Power Research Institute
South Korea

Email : sjmaeng@kepri.re.kr
Fax : 0082-42-865-5704
Sung-Jun Maeng
Radaition Safety Group
Nuclear Power Generation Lab. 
KEPRI

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