stepwise procedure in wipe test,, ISO standards , if any

[John Lam <lamhc@hkusua.hku.hk>]

Can any body give me advice on the following aspects in the wipe test of
the radioactive sources ?


I have looked into several stanndards, ANSI, BS. etc, there are few
sentences in describing radiation leak test, since I think wipe test is the
simplest tests to perform in usual manner. However, details in wipe test
are not mentioned clearly such as:
1.	no. of wipes needed for a radiation source at one time
2.	solvent which should be used, distilled water or alcohol or acetone ,
etc. I know that some beta source or alpha source may have very thin
metallic film as outer coatings which corrosive solvent should not be
applied, but how about the other solvent, are there really any guidelines
3.	what size of swap paper should be used
4.	material of the swap, cotton , filter paper, tissue paper if any.
5.	If liquid scintillation counter is not available  for beta source
measurement, what instrument can be used for beta, ionization type chamber
may not be appropriate all the time, particularly for very low energy beta
source like H3 or C14 which usual ionization, geiger counter or
contamination monitor may have very low sensitivity in the measurement thus
making the result the same as a background counting.
6.	In trying to measure those beta or alpha source with an electronic
contamination monitor like LB122, LB123 (EG$G) or NE Selectra surface
contamination monitor (IGP type) those equipment can only give count rate
instead of counts. There seems to be no way to access the actual counts
registered by those devices and count rate as seen by the device may not
necessarily be the same as the count rate as shown on the device, some
calibration factor/ count rate paralysis time may even unavailable too. So
are there any well-recognized way to calculate the uncertainty error or
even the MDA in the measurements.

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html