Virginia Administrative Code › Title 12 - HEALTH › Agency 5 - DEPARTMENT OF HEALTH › Chapter 481 - VIRGINIA RADIATION PROTECTION REGULATIONS › Part XVII - Schedules › Section 12VAC5-481-3770 - Determination of A1 and A2

Current through Register Vol. 40, No. 24, July 15, 2024
A. Values of
				  A1 and A2 for individual
				  radionuclides, which are the bases for many activity limits elsewhere in these
				  regulations, are given in Table 1 of this section. The curie (Ci) values
				  specified are obtained by converting from the Terabecquerel (TBq) value. The
				  terabecquerel values are the regulatory standard. The curie values are for
				  information only and are not intended to be the regulatory standard. Where
				  values of A1 and A2 are
				  unlimited, it is for radiation control purposes only. For nuclear criticality
				  safety, some materials are subject to controls placed on fissile
				  material.
B. For individual
				  radionuclides whose identities are known, but that are not listed in Table 1 or
				  Table 2 of this section, the A1 and A2
				  values or exempt material activity concentration and exempt
				  consignment activity values contained in Table 3 of this section may be used.
				  Otherwise, the licensee shall obtain prior agency approval for radionuclides
				  not listed in Table 1 or Table 2 of this section, before shipping the material.
				  The licensee shall submit requests for prior approval to the agency.
C. In the calculations of
				  A1 and A2 for a radionuclide not
				  in Table 1 of this section, a single radioactive decay chain, in which
				  radionuclides are present in their naturally occurring proportions, and in
				  which no daughter radionuclide has a half-life either longer than 10 days, or
				  longer than that of the parent radionuclide, shall be considered as a single
				  radionuclide, and the activity to be taken into account, and the
				  A1 or A2 value to be applied,
				  shall be those corresponding to the parent radionuclide of that chain. In the
				  case of radioactive decay chains in which any daughter radionuclide has a
				  half-life either longer than 10 days or greater than that of the parent
				  radionuclide, the parent and those daughter radionuclides shall be considered
				  as mixtures of different radionuclides.
D. For mixtures of radionuclides whose
				  identities and respective activities are known, the following conditions apply:
1. For special form radioactive material, the
				  maximum quantity transported in a Type A package is as follows:
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where B(i) is the activity of radionuclide (i) in special
					 form, and A1(i) is the A1 value
					 for radionuclide (i).
2. For
				  normal form radioactive material, the maximum quantity transported in a Type A
				  package is as follows:
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where B(i) is the activity of radionuclide (i) in normal
					 form, and A2(i) is the A2 value
					 for radionuclide (i).
3. If
				  the package contains both special and normal form radioactive material, the
				  activity that may be transported in the Type A package is as follows:
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Where B(i) is the activity of radionuclide i (i) as special
					 form radioactive material, A1(i) is the
					 A1 value for the radionuclide (i), C(j) is the activity
					 of radionuclide (j) as normal form radioactive material, and
					 A2(j) is the A2 value for
					 radionuclide (j).
4.
				  Alternatively, the A1 value for mixtures of special form
				  material may be determined as follows:
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where f(i) is the fraction of activity for radionuclide (i)
					 in the mixture, and A1(i) is the appropriate
					 A1 value for radionuclide (i).
5. Alternatively, the
				  A2 value for mixtures of normal form material may be
				  determined as follows:
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where f(i) is the fraction of activity for radionuclide (i)
					 in the mixture, and A2(i) is the appropriate
					 A2 value for radionuclide (i).
6. The exempt activity concentration for
				  mixtures of nuclides may be determined as follows:
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where f(i) is the fraction of activity concentration of
					 radionuclide (i) in the mixture, and A(i) is the activity concentration for
					 exempt material containing radionuclide (i).
7. The activity limit for an exempt
				  consignment for mixtures of radionuclides may be determined as follows:
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where f(i) is the fraction of activity of radionuclide (i)
					 in the mixture, and A(i) is the activity limit for exempt consignments for
					 radionuclide (i).