Oregon Department of Energy

Energy Facility Siting Council - Chapter 345

Division 50

RADIOACTIVE WASTE MATERIALS

Exempt Liquid and Solid Concentrations, Exempt Quantities

(Tables 1 and 2 of OAR 345 Division 50. See notes at the end of this table.)

Element
↑ ↓
Atomic Number
↑ ↓
Chemical Symbol
↑ ↓
Isotope
↑ ↓
Concentration* (See Table 1)
↑ ↓
Quantity (See Table 2)
↑ ↓
Note 1:

Many radioisotopes transform into isotopes that are also radioactive. In expressing the concentrations in Column 5 ("Concentration") of Table 1, the activity stated is that of the parent isotope and takes into account the daughters.

Note 2:

For purposes of OAR 345-050-0025, where a combination of isotopes is involved, the limit for the combination should be derived as follows:


Determine for each isotope in the product the ratio between the radioactivity concentration present in the product and the exempt radioactivity concentration established in Column 5 ("Concentration") of Table 1 for the specific isotope when not in combination.


The sum of such ratios must not exceed "1".

Example:
Concentration of Isotope A in Product Exempt Concentration of Isotope A
 + 
Concentration of Isotope B in Product Exempt Concentration of Isotope B
 ≤  1

Note 3:

Not included in division 50 tables - see OAR 345-050-0020 (2) and -0025 (2).

Note 4:

When Th-232 is present - Not included in division 50 tables - see OAR 345-050-0020 (3) and -0025 (3).

Note 5:

When certain wastes are out of equilibrium with U-238 - Not included in division 50 tables - see OAR 345-050-0020 (4).

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Exempt Concentrations in Air and Water Above Natural Background

(Table 3 of OAR 345 Division 50. See notes at the end of this table.)

Air Water
Element
↑ ↓
Atomic Number
↑ ↓
Chemical Symbol
↑ ↓
Isotope
↑ ↓
Soluble (qty/ml)
↑ ↓
Insoluble (qty/ml)
↑ ↓
Submersion* (qty/ml)
↑ ↓
Soluble (qty/ml)
↑ ↓
Insoluble (qty/ml)
↑ ↓
Note 1:

"Submersion" values given are for submersion in a semispherical infinite cloud of airborne material.

Note 2:

These radon concentrations are appropriate for protection from radon-222 combined with its short-lived daughters. Alternatively, this value may be replaced by one-thirtieth (1/30) of a working level. (A "working level" is defined as any combination of short-lived radon-222 daughters, polonium-218, lead-214, bismuth-214, and polonium-214, in one liter of air, without regard to the degree of the equilibrium, that will result in the ultimate emission of 1.3e5 MeV of alpha particle energy.)

Note 3:

For soluble mixtures of U-238, U-234, and U-235 in air, chemical toxicity may be the limiting factor. If the percent by weight (enrichment) of U-235 is less than 5, the concentration value of 0.007 milligrams uranium per cubic meter of air. The specific activity for natural uranium is 6.77e-7 curies per gram uranium. The specific activity for other mixtures of U-238, U-235, and U-234, if not known, shall be:



SA = 3.6e-7 Ci/g U     U-depleted


SA = (0.4 + 0.38 E + 0.0034 E2) 10-6      E ≥ 0.72


where E is the percentage by weight of U-235, expressed as percent.


Note 4:

In any case where there is a mixture in air or water of more than one radionuclide, the limiting values for purposes of this table should be determined as follows:

  1. If the identity and concentration of each radionuclide in the mixture are known, the limiting values should be derived as follows:

    Determine, for each radionuclide in the mixture, the ratio between the quantity present in the mixture and the limit otherwise established in this table for the specific radionuclide when not in a mixture. The sum of such ratios for all the radionuclides in the mixture may not exceed "1" (i.e., "unity").

    Example: If radionuclides a, b, and c are present in concentrations Ca, Cb, and Cc and if the applicable maximum permissible concentrations (MPCs) are MPCa, MPCb, and MPCc respectively, then the concentrations shall be limited so that the following relationship exists:

    (Ca / MPCa) + (Cb / MPCb) + (Cc / MPCc) ≤ 1

  2. If either the identity or the concentration of any radionuclide in the mixture is not known, the limiting values for purposes of this table shall be:
    1. For purposes of the 'Air' columns of this table... 2e-14
    2. For purposes of the 'Water' columns of this table... 3e-8

  3. If any of the conditions specified below are met, the corresponding values specified below may be used in lieu of those specified in paragraph 2 above.

    1. If the identity of each radionuclide in the mixture is known but the concentration of one or more of the radionuclides in the mixture is not known, the concentration limit for the mixture is the limit specified for this table for the radionuclide in the mixture having the lowest concentration limit; or

    2. If the identity of each radionuclide in the mixture is not known, but it is known that certain radionuclides specified in this table are not present in the mixture, the concentration limit for the mixture is the lowest concentration limit specified in this table for any radionuclide which is not known to be absent from the mixture; or

      • If it is known that Sr-90, I-125, I-126, I-129, I-131, I-133, Pb-210, Po-210, At-211, Ra-223, Ra-224, Ra-226, Ac-227, Ra-228, Th-230, Pa-231, Th-232, Th-nat, Cm-248, Cf-254, and Fm-256 are not present, Water = 3e-6 µCi/ml.

      • If it is known that Sr-90, I-125, I-126, I-129, I-131, I-133, Pb-210, Po-210, Ra-223, Ra-226, Ra-228, Pa-231, Th-nat, Cm-248, CF-254, and Fm-256 are not present, Water = 2e-6 µCi/ml.

      • If it is known that Sr-90, I-129 I-125, I-126, I-131, Pb-210, Ra-226, Ra-228, Cm-248 and Cf-254 are not present, Water = 6e-7 µCi/ml.

      • If it is known that I-129, Ra-226, and Ra-228 are not present, Water = 1e-7 µCi/ml.

      • If it is known that alpha-emitters and Sr-90, I-129, Pb-210, Ac-227, Ra-228, Pa-230, Pu-241, and Bk-249 are not present, Air = 1e-10 µCi/ml.

      • If it is known that alpha-emitters and Pb-210, Ac-227, Ra-228, and Pu-241 are not present, Air = 1e-11 µCi/ml.

      • If it known that alpha-emitters and Ac-227 are not present, Air = 1e-12 µCi/ml.

      • If it is known that Ac-227, Th-230, Pa-231, Pu-238, Pu-239, Pu-240, Pu-242, Pu-244, Cm-248, Cf-249, and Cf-251 are not present, Air = 1e-13 µCi/ml.


  4. If a mixture of radionuclides consists of uranium and its daughters ore dust prior to chemical separation of the uranium from the ore, the values specified below may be used for uranium and its daughters through radium-226, instead of those from paragraph 1, 2, or 3 above.

    For purposes of this the Air columns of this table, 3e-12 µCi/ml gross alpha activity; 2e-12 µCi/ml natural uranium; or 3 micrograms per cubic meter of air natural uranium.

  5. For purposes of this note, a radionuclide may be considered as not present in a mixture if (a) the ratio of the concentration of that radionuclide in the mixture (Ca) to the concentration limit for that radionuclide specified in this table (MPCa) does not exceed 1/10, (i.e., Ca / MPCa ≤ 1/10) and (b) the sum of such ratios for all radionuclides considered as not present in the mixture does not exceed 1/4, (i.e., Ca / MPCa + Cb / MPCb + ... ≤ 1/4).

    Note: To convert µCi/ml to SI units of megabecquerels per liter multiply the above values by 37.

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