No Subject

["J. J. Rozental" <josrozen@netmedia.net.il>]

Dear all,
I am studying the concept of Clearance Levels for radionuclides, that's
mean, levels of radionuclides below which sources of radiation may be
released from regulatory control, as stated in the  IAEA BSS 115-I, 1994.
Historically, the lower limit of concentration 2 nCi/g goes down to the
first IAEA Safety Series, Safe Handling of Radioisotopes, Edition 1958, and
subsequently in the IAEA's recommendation for transport. Still, today, in
that document "radioactive material shall mean any material having a
specific activity greater than 70 kBq/kg (2 nCi/g)- IAEA Safety Series 6,
(As amended 1990).Many developing countries consider such value in its
regulation for waste disposal.

 The two basic criteria for determining, from a radiation standpoint,
whether or not a source can be exempted or cleared from regulatory control,
should be based on the ICRP 60, 1990 and  IAEA BSS (above), that's mean:

-- Individual risks must be sufficiently low  not to warrant regulatory
concern, that's mean, the definition of the level of individual dose that
can be regarded as "trivial"-- individual doses to average members of the
critical group --

-- Radiation protection must be optimized, taking the cost of regulatory
control into account, that's mean, the optimization analysis techniques;

For such unconditional clearance I will appreciate very much to receive any
comment from competent authority, national or international organization,
or expert on the subject, specially on the following topics:

1) Clearance level: Single value in the country? As 70 kBq/Kg or any other.
2) Two values in the country?  One for alfa and other for beta/gamma;(in
this case on which basis the values were fixed);
3) What was the consideration on collective dose commitment resulting from
one year of the practice (manSv per year of practice);
4) Will the waste in such clearance levels be excluded of requirements for
disposal? That's mean the disposal of that waste jointly with other
hazardous material, as biological?
5) In nearly all practical cases, more than one radionuclide will be
involved, including different classes of radiotoxicity, how will the concept
to determine if a mixture of radionuclides is at or below the clearance level?
6) What was the consideration in case of mixing with radionuclides found in
natural environment, or materials used in building, and for reuse?

			                   J. J. Rozental
                               Consultant, Radiation Safety and Regulation

<josrozen@netmedia.net.il>
Israel