Fw: Leak test of Kr-85 radioactive source- -

[Emil <kerrembaev@YAHOO.COM>]

Greetings,



In the leak test of the sealed vessels helium

used as a leaking substance and mass spectrometer

to detect the leak rate. It is a very sensitive

method. 

Check welding of the sealed/special form material

source with the mass spectrometer it would be the

most sensitive rather looking for betas.

Detection efficiency will be in the range of

....amount of the escaped atoms + collection

efficiency + detector efficiency => MDA ~ 50 dpm

(at the best), you can not count Kr-85 for long

time obviously it will be escaping from the

radiation detector pretty quick...Fluctuations in

detection of the flow monitor will be sizable.



Ask some one in the Physics Department in your

local University, I am sure they will be able to

help you.

As soon as you know Kr-85 escape rate you can

calculate activity per minute. 





Emil





Date: Tue, 20 Aug 2002 08:15:42 -0700From:

"Michael Kay" 

Subject: Fw: Leak test of Kr-85 radioactive

source- ----- Original Message -----

From: "Michael Kay" To: "Fazal-ur-Rehman" Sent:

Tuesday, August 20, 2002 8:14 AM

Subject: Re: Leak test of Kr-85 radioactive

source

> The NRC regulations exempt Kr-85 sources from

leak tests. The ways to tell

> if the source is leaking involve a continuous

air monitor for the areaBELOW

> (Kr is heavier than air), or the notice of a

change in the measured value

> requiring a larger than normal calibration

correction (greater thanrequired

> by decay).>> Michael A. Kay, ScD, CHMM

> Consultant to a firm using Web Thickness

Gauges> Containing Kr-85>

> makay@alum.mit.edu> ----- Original Message

-----> From: "Fazal-ur-Rehman" 

> To: > Cc: > Sent: Tuesday, August 20, 2002 2:45

AM

> Subject: Leak test of Kr-85 radioactive

source>>> > Dear Radsafers> >

> > Could anyone tell us how to do leak test of a

radioactive Kr-85 source.

> This> > source is a beta emitter used as a

thickness guage. In my openion,

Kripton

> > is an inert gas and it will not stick on the

surfaces and will be taken

> away> > by the air, therefore, we can not take

smear or wipe samples to see

> whether

> > the source is leaking or not. We would

appreciate it if somebody could

> > suggest the proper way to find the leakage of

this source.> >

> > Thank you in advance.> >> > Fazal-ur-Rehman>

> P.O. Box # 1292

> > Department of Physics> > King Fahd University

of Petroleum & Minerals

> > Dhahran 31261> > Saudi Arabia> >



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