40 CFR Appendix D to Part 61, Methods for Estimating Radionuclide Emissions

Appendix D to Part 61 - Methods for Estimating Radionuclide Emissions
1. Purpose and Background

Facility owners or operators may estimate radionuclide emissions to the atmosphere for dose calculations instead of measuring emissions. Particulate emissions from mill tailings piles should be estimated using the procedures listed in reference re #2. All other emissions may be estimated by using the “Procedures” listed below, or using the method described in reference #1.

2. Procedure

To estimate emissions to the atmosphere:

(a) Determine the amount (in curies) used at facilities for the period under consideration. Radioactive materials in sealed packages that remain unopened, and have not leaked during the assessment period should not be included in the calculation.

(b) Multiply the amount used by the following factors which depend on the physical state of the radionuclide. They are:

(i) 1 for gases;

(ii) 10−3 for liquids or particulate solids; and

(iii) 10−6 for solids.

If any nuclide is heated to a temperature of 100 degrees Celsius or more, boils at a temperature of 100 degrees Celsius or less, or is intentionally dispersed into the environment, it must be considered to be a gas.

(c) If a control device is installed between the place of use and the point of release, multiply emissions from (b) by an adjustment factor. These are presented in Table 1.

Table 1 - Adjustment to Emission Factors for Effluent Controls

Controls Types of radionuclides controlled Adjustment factor to emissions Comments and conditions
HEPA filters Particulates 0.01 Not applicable to gaseous radionuclides; periodic testing is prudent to ensure high removal efficiency.
Fabric filter Particulates 0.1 Monitoring would be prudent to guard against tears in filter.
Sintered metal Particulates 1 Insufficient data to make recommendation.
Activated carbon filters Iodine gas 0.1 Efficiency is time dependent; monitoring is necessary to ensure effectiveness.
Douglas bags: Held one week or longer for decay Xenon 0.5/wk Based on xenon half-life of 5.3 days;
Douglas bags: Released within one week Xenon 1 Provides no reduction of exposure to general public.
Venturi scrubbers Particulates
Although venturis may remove gases, variability in gaseous removal efficiency dictates adjustment factor for particulates only.
Packed bed scrubbers Gases 0.1 Not applicable to particulates.
Electrostatic precipitators Particulates 0.05 Not applicable for gaseous radionuclides
Xenon traps Xenon 0.1 Efficiency is time dependent; monitoring is necessary to ensure effectiveness.
Fume hoods All 1 Provides no reduction to general public exposures.
Vent stacks All 1 Generally provides no reduction of exposure to general public.

(1) Environmental Protection Agency, “A Guide for Determining Compliance with the Clean Air Act Standards for Radionuclides Emissions from NRC-Licensed and Non-DOE Federal Facilities”, EPA 520/1-89-002, January 1989.

(2) Nuclear Regulatory Commission, “Methods for Estimating Radioactive and Toxic Airborne Source Terms for Uranium Milling Operations”, U.S. Nuclear Regulatory Commission Regulatory Guide 3.59, March 1987.

[ 54 FR 51711, Dec. 15, 1989]

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

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United States Code

Title 40 published on 10-May-2017 04:28

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 40 CFR Part 61 after this date.

  • 2017-05-11; vol. 82 # 90 - Thursday, May 11, 2017
    1. 82 FR 21927 - Delegation of New Source Performance Standards and National Emission Standards for Hazardous Air Pollutants for the States of Arizona and Nevada
      GPO FDSys XML | Text
      Direct final rule.
      This rule is effective on July 10, 2017 without further notice, unless EPA receives adverse comments by June 12, 2017. If we receive such comments, we will publish a timely withdrawal in the Federal Register to notify the public that this direct final rule will not take effect.
      40 CFR Parts 60, 61 and 63