RE: Fuel Pool Cooling High Dose Rates -Reply

[Jack Priest <jmpriest@tol-ed.com>]

Many control components, e.g. control rods are composed of silver, indium, and cadmium. Normal wear and tear due to rod movement is the biggest contributor to Ag110m in your RCS. O-rings would not be a significant contributor.

	Jack Priest
            Health Physics
            Davis-Besse NPS, Centerior Energy
	jmpriest@tol-ed.com


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From: 	RON L. SHEPHERD[SMTP:SHEPHRL@GWSMTP.NU.COM]
Sent: 	Thursday, July 17, 1997 2:06 PM
To: 	Multiple recipients of list
Subject: 	Fuel Pool Cooling High Dose Rates -Reply

Mike:

The only source of Silver that I am aware of would be the Reactor Head 'O'
Ring.
Normally you would not see any concentration of Silver in the coolant so I
would speculate that a piece of the ring had somehow entered the system, gotten
ground up by the Coolant Pumps and become irradiated by the core during
operation.

For removal you could try TriNuc filtration in the pool and a temporary
filtration system connected to the Fuel Pool Cooling System however exercise
caution because the filters will most likely be reading orders of magnitude
higher that what you are seeing from the system due to the loss of the water
shielding you have in the piping, pumps etc and the shielding from the pipe
walls and pump housings.

In any case I would place the highest priority on evaluating the efficiency of
your friskers and personnel contamination monitors to detect Ag 110M so that
you don't release equipment or personnel that are contaminated by this Isotope.

Good luck.

Ron Shepherd
Radiological Safety Coordinator
Millstone Station
SHEPHRL@GWSMTP.NU.COM

The opinions expressed are my own and do not reflect the opinion of NU