Regulatory Guide 4.20: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(Created page by program invented by StriderTol)
Line 1: Line 1:
{{Adams
{{Adams
| number = ML110120299
| number = ML003739525
| issue date = 04/30/2012
| issue date = 12/31/1996
| title = Constraint on Releases of Airborne Radioactive Materials to the Environment for Licensees Other than Power Reactors.
| title = (Draft Issued as DG-8016), Constraint on Release of Airborne Radioactive Materials to the Environment for Licensees Other than Power Reactors
| author name =  
| author name =  
| author affiliation = NRC/RES
| author affiliation = NRC/RES
Line 9: Line 9:
| docket =  
| docket =  
| license number =  
| license number =  
| contact person = Bayssie, Mekonen, RES/DE/RGDB  251-7489
| contact person =  
| case reference number = DG-4018
| document report number = RG-4.20
| document report number = RG-4.020, Rev. 1
| package number = ML110100839
| document type = Regulatory Guide
| document type = Regulatory Guide
| page count = 12
| page count = 7
}}
}}
{{#Wiki_filter:The NRC issues regulatory guides to describe and make available to the public methods that the NRC staff considers acceptable for use in implementing specific parts of the agency's regulations, techniques that the staff uses in evaluating specific problems or postulated accidents, and data that the staff needs in reviewing applications for permits and licenses.  Regulatory guides are not substitutes for regulations, and compliance with them is not required.  Methods and solutions that differ from those set forth in regulatory guides will be deemed acceptable if they provide a basis for the findings required for the issuance or continuance of a permit or license by the Commission.
{{#Wiki_filter:U.S. NUCLEAR REGULATORY  
 
COMMISSION  
Electronic copies of this guide and other recently issued guides are available through the NRC's public Web site under the Regulatory Guides document collection of the NRC Library at http://www.nrc.gov/reading-rm/doc-collections/ and through the NRC's Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html, under Accession No. ML110120299.  The regulatory analysis may be found in ADAMS under Accession No. ML110120351.
REGULATORY
 
December 199 GUIDE OFFICE OF NUCLEAR REGULATORY  
This guide was issued after consideration of comments received from the public.  The public comments and NRC staff response to them may be found in ADAMS under Accession No. ML110120371.
RESEARCH REGULATORY
 
GUIDE 4.20 (Draft issued as DG-8016) CONSTRAINT  
U.S. NUCLEAR REGULATORY COMMISSION
ON RELEASES OF AIRBORNE RADIOACTIVE  
April 2012 Revision 1 REGULATORY GUIDE  
MATERIALS  
OFFICE OF NUCLEAR REGULATORY RESEARCH
TO THE ENVIRONMENT  
  REGULATORY GUIDE 4.20 (Draft was issued as DG-4018, dated April 2010) CONSTRAINT ON RELEASES OF AIRBORNE RADIOACTIVE MATERIALS TO THE ENVIRONMENT FOR LICENSEES OTHER THAN POWER REACTORS  
FOR LICENSEES  
OTHER THAN POWER REACTORS  


==A. INTRODUCTION==
==A. INTRODUCTION==
This regulatory guide provides guidance on methods that the staff of the U.S. Nuclear Regulatory Commission (NRC) considers acceptable for meeting the constraint on airborne emissions of radioactive material to the environment as described in Title 10, Section 20.1101(d), of the Code of Federal Regulations (10 CFR 20.1101(d)) (Ref. 1). In 1996, the NRC added a constraint to 10 CFR Part 20, "Standards for Protection against Radiation," to remove dual regulation by the NRC and the U.S. Environmental Protection Agency (EPA) and to provide an "ample margin of safety" to members of the public from airborne emissions of radioactive material to the environment.
In 10 CFR Part 20, "Standards for Protection Against Radiation," § 20.1302(b)
requires that: A licensee shall show compliance with the annual dose limit in § 20.1301 by (1) Demonstrating by measurement or calculation that the total effective dose equivalent to the individual likely to receive the highest dose from the licensed operation does not exceed the annual dose limit; or (2) Demonstrat ing that (i) The annual average concentrations of ra dioactive material released in gaseous and liquid effluents at the boundary of the unrestricted area do not exceed the values specified in Table 2 of Appen dix B to Part 20; and (ii) If an individual were contin uously present in an unrestricted area, the dose from external sources would not exceed 0.002 rem (0.02 mSv) in an hour and 0.05 rem (0.5 mSv) in a year.  In addition, 10 CFR 20.1101(d)  
requires that: To implement the ALARA [as low as is reasonably achievable]
requirements of § 20.1101(b), and not withstanding the requirements in § 20.1301 of this part, a constraint on air emissions of radioactive ma terial to the environment, excluding radon-222 and its daughters, shall be established by licensees other USNRC REGULATORY
GUIDES Regulatory Guides are issued to describe and make available to the public such informa tion as methods acceptable to the NRC staff for implementing specific pals of the Com mission's regulations, techniques used by the staff in evaluating specific problems or pos tulated accidents, and data needed by the NRC staff in its review of applications for per mits and licenses Regulatory guides are not substitutes for regulations, and compliance with them is not required.


The regulation at 10 CFR 20.1101(d) states the following: 
Methods and solutions different from Itho sat out in the guides will be acceptable if they provide a basis for the findings requisite to the issuance or con tinuance of a permit or license by the Commission.
To implement the ALARA [as low as is reasonably achievable] requirements of § 20.1101 (b), and notwithstanding the requirements in § 20.1301 of this part, a constraint on air emissions of radioactive material to the environment, excluding Radon-222 and its daughters, shall be established by licensees other than those subject to § 50.34a, such that the individual member of the public likely to receive the highest dose will not be  expected to receive a total effective dose equivalent in excess of 10
mrem [millirem] (0.1 mSv [millisievert]) per year from these emissions.  If a licensee subject to this Rev. 1 of RG 4.20, Page 2  requirement exceeds this dose constraint, the licensee shall report the exceedance as provided in § 20.2203 and promptly take appropriate corrective action to ensure against recurrence.


This regulatory guide contains information collection requirements covered by 10 CFR Part 20 that the Office of Management and Budget (OMB) approved under OMB control number 3150-0014.
This guide was issued after consideration of comments received from the public. Com ments and suggestions for improvements in these guides are encouraged at all times, and guides will be revised, as approprate, to accommodate comments and to reflect new in formation or experience.


The NRC may neither conduct nor sponsor, and a person is not required to respond to, an information collection request or requirement unless the requesting document displays a currently valid OMB control number.  This regulatory guide is a rule as designated in the Congressional Review Act (5 U.S.C. 801-808).  However, OMB has not found it to be a major rule as designated in the Congressional Review Act.
Written comments may be submitted to the Rules Review and Directives Branch, DFIPS.  ADM, U S Nuclear Regulatory Commission, Washington, DC 20555-0001.


==B. DISCUSSION==
than those subject to 10 CFR 50.34a, such that the individual member of the public likely to receive the highest dose will not be expected to receive a total effective dose equivalent in excess of 10 mrem (0.1 mSv) per year from these emissions.
Background In 1996, the NRC added regulations regarding a constraint on airborne emissions of radioactive materials to the environment as part of an agreement with EPA to resolve dual regulation of airborne emissions of radioactive material under both the Atomic Energy Act of 1954, as amended (Ref. 2), and the Clean Air Act of 1970, as amended (Ref. 3).  EPA subsequently rescinded its Clean Air Act regulations in Subpart I, "National Emission Standards for Radionuclide Emissions from Federal Facilities Other Than Nuclear Regulatory Commission Licensees Not Covered by Subpart H," of 40 CFR Part 61, "National Emission Standards for Hazardous Air Pollutants" (Ref. 4), as they applied to NRC licensees other than power reactors.  As Low As Reasonably Achievable Components of an effective radiation protection program, as required by 10 CFR 20.1101, "Radiation Protection Programs," include, in part, radiation exposure control, written procedures and policies, control of radioactive materials, radioactive contamination control, radioactive waste management, training, program reviews, and audits.


The NRC staff examines licensee programs to determine whether they comply with the requirements in 10 CFR Part 20. This guide addresses only a part of a licensee's overall radiation protection program.  Specifically, it addresses methods that licensees can use to demonstrate that they meet the constraint on airborne emissions of radioactive material to the environment.  In addition to controlling doses from airborne emissions of radioactive material to the environment, licensees must implement a radiation protection program that controls liquid effluents and dose rates in unrestricted areas.  Many NRC licensees possess source, byproduct, or special nuclear materials in a form that would not result in airborne emissions of radioactive material to the environment.  These licensees include radiographers, well loggers, and other users of sealed sources.  These licensees do not need to take any actions to demonstrate that they meet the constraint on airborne emissions of radioactive material to the environment.
If a licensee subject to this requirement exceeds this dose con straint, the licensee shall report the exceedance as provided in 10 CFR 20.2203 and promptly take ap propriate corrective action to ensure against recurrence.


The dose limits in 10 CFR Part 20 are based on limiting dose to an acceptably low level of risk to the exposed individual.  However, any radiation dose may carry some risk; therefore, the NRC requires licensees to take actions, to the extent practicable, using procedures and engineering controls to further reduce risk below the levels implicit in the dose limits in keeping with the ALARA principle. This is one Rev. 1 of RG 4.20, Page 3  goal of radiation protection programs.  To achieve this goal, licensees must control the way radioactive materials are handled from receipt through disposal.
This regulatory guide provides guidance on meth ods acceptable to the NRC staff for compliance with the constraint on air emissions to the environment.


Guidance on ALARA programs is available outside of this regulatory guide.  Some generically applicable guidance that contains programmatic information includes the following: 
If addi tional significant comments are received in the first year following its issuance, the staff will revise the guide as ap propriate.
a. Regulatory Guide 8.10, "Operating Philosophy for Maintaining Occupational Radiation Exposures As Low As Is Reasonably Achievable" (Ref. 5), 
b. Regulatory Guide 8.37, "ALARA Levels for Effluents from Materials Facilities" (Ref. 6),  c. Regulatory Guide 4.21, "Minimization of Contamination and Radioactive Waste Generation:  Life-Cycle Planning" (Ref. 7),  d. National Council on Radiation Protection and Measurements (NCRP) Report No. 127, "Operational Radiation Safety Program," issued June 1998 (Ref. 8), and e. NCRP Statement No. 8, "The Application of ALARA for Occupational Exposures," dated June 8, 1999 (Ref. 9).
Constraints A dose limit is a basic radiation protection standard that is the upper acceptable bound of radiation dose and should not be exceeded.  The dose limit to members of the public (100 mrem per year (1 mSv per year)) includes doses from all pathways, including direct radiation, liquid effluents, and airborne effluents.  The constraint, in this case, may be interpreted as that fraction of the public dose limit allocated to airborne emissions to ensure that doses are ALARA through this particular release pathway.  Licensees are required to design their facilities and structure operations such that airborne emissions of radioactive materials generated from operations result in doses to the public that are below the constraint.  The constraint serves as a starting point, or upper level, for ALARA assessments.  If licensees exceed the constraint on airborne emissions, they are required to report the radiation dose to the NRC and to take corrective actions to lower the dose below the constraint value.  Enforcement action would occur only if a licensee fails to report an exceedance of the constraint or fails to take appropriate and timely corrective actions.  C.  STAFF REGULATORY GUIDANCE
The following paragraphs describe when the requirements to meet the constraint on airborne emissions of radioactive materials to the environment apply and the methods that a licensee can use to demonstrate that it meets the constraint.  The methods described below are acceptable to the NRC staff for use by NRC licensees other than power reactors to determine the dose resulting from airborne emissions of radioactive material to the environment.  Licensees should choose a monitoring period (i.e., a year, month, or quarter) to demonstrate that they meet the airborne emissions constraint in accordance with 10 CFR 20.1101(d).  For most licensees, the monitoring period will be 1 year.


Rev. 1 of RG 4.20, Page 4  1. Applicable Exclusions to the Constraint on Environmental Airborne Emissions The NRC may grant licensees an exemption, on a case-specific basis, to use guidance and methods that have been developed since the release of 10 CFR Part 20.  (See SECY-01-0148, "Process for Revision of 10 CFR Part 20 regarding Adoption of International Commission on Radiological Protection (ICRP) Recommendations on Occupational Dose Limits and Dosimetric Models and Parameters," dated August 2, 2001 (Ref. 10), for background information.)  Licensees granted exemptions to use dosimetry guidance other than that on which 10 CFR Part 20 is based may use that guidance and associated methods to demonstrate that they meet the dose constraint.
Guidance on ALARA programs can be found in other regulatory guides. Although these guides deal primarily with occupational exposure and may be specif ic to one type of licensee, they contain programmatic in formation that may be useful to all licensees.


The following information provides types of licensees and sources of radioactive material that may be excluded from consideration in determining whether the dose constraint is met:  
These guides are: 0 Regulatory Guide 8.10, "Operating Philosophy for Maintaining Occupational Radiation Exposures As Low As Is Reasonably Achievable." This guide de lineates the components of an ALARA program.The guides are issued in the following ten broad divisions:
a. Licensees do not need to take any actions to demonstrate that they meet the dose constraint if they (1) operate a nuclear power reactor subject to 10 CFR 50.34a, "Design Objectives for Equipment To Control Releases of Radioactive Material in Effluents-Nuclear Power Reactors" (Ref. 11), or (2) possess and use radionuclides only in the form of sealed sources.
1. Power Reactors 2. Research and Test Reactors 3. Fuels and Matenels Facilities
4. Environental and Siting 5. Materials and Plant Protection
& Products 7. Transportation S Occupational Health 9g Antitrust and Financial Review 10 General Single copies of regulatory guides may be obtained free of charge by writing the Office of Adminstration, Attention:
Distribution and Services Section, U.S. Nuclear leguloy Commission.


b. Calculations do not need to include radioactive materials in sealed containers that remain unopened and that have not leaked during the assessment period.  Radiopharmaceuticals in unopened manufacturers' packages that are not leaking and materials in undamaged shipping containers are examples of sealed containers. Independent spent fuel storage canisters that do not have vents to the atmosphere may also be considered sealed containers.
Washington, DC 20655-0001;
or by ftax at (301)415-2280
Issued guides may also be purchased from the National Technical Information Service onr a standing order basis. Details on this service may be obtained by writing NTIS. 5285 Port Royal Road, Springfield, VA 22161.


c. Effluents from patients who have received radiopharmaceuticals do not need to be included if the licensee uses an inventory approach to demonstrate that it has met the constraint. If the licensee uses measured or calculated concentrations of radioactive materials in the environment to demonstrate that it has met the constraint, the contribution from patients is deemed insignificant and does not need to be considered.
"* Regulatory Guide 8.18, "Information Relevant to Ensuring that Occupational Radiation Exposures at Medical institutions Will Be As Low As Reasonably Achievable." " Regulatory Guide 8.31, "Information Relevant to Ensuring that Occupational Radiation Exposures at Uranium Mills Will Be As Low As Is Reasonably Achievable." "* Regulatory Guide 8.37, "ALARA Levels for Efflu ents from Materials Facilities." 0 Regulatory Guide 10.8, "Guide for the Preparation of Applications for Medical Use Programs." Sec tion 1.3 and Appendix G deal specifically with ALARA programs for medical facilities.


d. If a determination can be made that some detected materials did not result from the licensed activities of the licensee, only radioactive materials from the licensed activity need to be considered.  Materials that are windblown from other facilities do not need to be considered.
In addition, further information can be found in Re vision 1 to NUREG-0267, "Principles and Practices for Keeping Occupational Radiation Exposures As Low As Reasonably Achievable" (October 1982).1 The information collections contained in this regu latory guide are covered by the requirements of 10 CFR Part 20, which were approved by the Office of Manage ment and Budget, approval number 3150-0014.


e. In determining the member of the public likely to receive the highest dose from airborne emissions of radioactive material to the environment from licensed operations, licensees do not need to consider nonresidents within the facility boundary.  Although the constraint of 10 mrem (0.1 mSv) per year does not apply within the facility boundary, the public dose of 100 mrem
The NRC may not conduct or sponsor, and a person is not re quired to respond to, a collection of information unless it displays a currently valid OMB control number.
(1 mSv) per year and ALARA would continue to apply to members of the public within the facility.


2. Calculation of Dose to the Member of the Public Likely To Receive the Highest Dose from Airborne Effluents In demonstrating compliance with 10 CFR 20.1101(d), licensees should determine whether there have been any facility or design modifications, increases in radionuclide inventories, or operational changes and whether any of these factors resulted in variations in airborne emissions since the last monitoring period.  If the licensees' operations have not changed, the review of licensed operations and the demonstration of meeting the constraint will be relatively straightforward.
==B. DISCUSSION==
The dose limits in 10 CFR Part 20 are based on limit ing dose to an acceptably low level of risk to the exposed individual.


Rev. 1 of RG 4.20, Page 5  Estimates of emissions may either be based on measurements of effluents (see Regulatory Guide 4.16, "Monitoring and Reporting Radioactivity in Releases of Radioactive Materials in Liquid and Gaseous Effluents from Nuclear Fuel Processing and Fabrication Plants and Uranium Hexafluoride Production Plants" (Ref. 12)) or calculated using the inventory of radioactive materials present at a facility.  Estimates of actual emissions that do not involve a measured effluent quantity should take into consideration the physical state and inventory of licensed radioactive materials, emissions controls (if applicable), and atmospheric conditions.  Release estimates should include licensed material that is not otherwise excluded from consideration as discussed in Regulatory Position C.1.  American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, "Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities" (Ref. 13), proposes a simple method to estimate potential releases.  This method involves the multiplication of the physical inventory of material by a release fraction based on the state of the material.  Emission controls affecting the release of materials may either be assumed to have been functional, if there is reasonable assurance the controls were reliable during the release period, or otherwise considered ineffectual during the release.  Atmospheric conditions and dose estimates can be addressed consistent with the remainder of this section.
However, any radiation exposure may carry some risk. Thus, the NRC requires licensees to take ac tions, to the extent practicable, utilizing procedures and engineering controls to further reduce risk below the lev els implicit in the dose limits in keeping with the princi ple that exposures should be as low as is reasonably achievable.


The methods described below represent a graded approach for demonstrating that the constraint has been met, from the method requiring the fewest site-specific data and, therefore, the most conservative, to more rigorous methods with more realistic results.  All methods are acceptable for demonstrating compliance with 10 CFR 20.1101(d).  The graded approach is intended to allow users to pick the method that most closely corresponds to the amount of site-specific information that they want to collect.  The accuracy of the dose estimate should only increase as the licensee uses more site-specific information and the resulting dose estimate becomes less conservative, but it should not be underestimated.
This is the goal and purpose for radiation protection programs.


a. The simplest screening technique is to assume that the airborne concentration at the receptor is equal to the airborne concentration measured or calculated at the point of release.
In order to achieve this goal, li censees must control the way radioactive material is han dled from receipt through disposal.


The derivation of concentrations in Column 1 of Table 2 of Appendix B, "Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for Release to Sewerage," to 10 CFR Part 20, are presented in the discussions preceding the tables in Appendix B. For radionuclides governed by the stochastic ALI, the occupational stochastic inhalation ALI was divided by 2.4x10
ALARA Components of an effective radiation protection program, as required by 10 CFR 20.1101, include radi ation exposure control, written procedures and policies, control of radioactive materials, radioactive contamina tion control, radioactive waste management, training, program reviews, and audits.  'Copies are available for purchase from the U.S. Government Printing Office, PO. Box 37082, Washington, DC 20013-7082, telephone
9 milliliters, relating the inhalation ALI to the occupational DAC, and was then divided by a factor of 300.  The factor of 300 includes (1) a factor of 50 to relate the 5-rem annual occupational dose limit to the 0.1-rem limit for members of the public, (2) a factor of 3 to adjust for the difference in exposure time and the inhalation rate for a worker and for members of the public, and (3) a factor of 2 to adjust the occupational values (derived for adults) so that they are applicable to other age groups.
(202) 512-2249;
or from the National Technical Information Service by writing NTIS at 5285 Port Royal Road, Springfield, VA 22161. Co pies are available for inspection or copying for a fee from the NRC Pub lic Document Room at 2120 L Street NW., Washington, DC; the PDR's mailingaddress is Mail StopLL-6, Washington, DC20555; telephone
(202)634-3273;
fax (202)634-3343.


For radionuclides limited by submersion (external dose), the occupational DAC in Table 1, Column 3, was divided by 219. The factor of 219 is composed of a factor of 50, as described previously, and a factor of 4.38, relating occupational exposure for 2,000 hours per year to full-time exposure (8,760 hours per year).  
The NRC staff examines licensee programs to deter mine whether they are in compliance with the require ments of 10 CFR Part 20. This guide addresses only a part of a licensee's overall radiation protection program.


The concentrations of radionuclides limited by the stochastic ALI in Table 2, Column 1, would produce an annual dose of 0.5 mSv (50 mrem) to a reference adult if the radionuclides are inhaled or ingested continuously over the course of a year.  The licensee can thus demonstrate that it meets the constraint if the annual average radionuclide concentration at the point of release is less than 20 percent of the "air" values in Table 2 and if the radionuclides present in effluent are limited by the stochastic ALI.
Specifically, it addresses methods for demonstrating compliance with the constraint on releases of airborne radioactive materials to the environment.


Rev. 1 of RG 4.20, Page 6 However, the concentrations of radionuclides limited by submersion dose in Table 2, Column 1 (mostly noble gases), would produce an annual dose of 1.0 mSv (100 mrem).  In that case, the licensee can demonstrate that it meets the constraint if the annual average radionuclide concentration at the point of release is less than 10 percent of the "air" values in Table 2.
In addition to controlling doses from the releases of airborne radioac tive materials to the environment, licensees must imple ment a radiation protection program that controls liquid effluents and dose rates in unrestricted areas.  Many NRC licensees possess source, byproduct, or special nuclear material in a form that would not cause doses to members of the public from releases of airborne radioactive material to the environment.


If the radionculides present include a combination of those limited by the stochastic ALI and submersion dose, the licensee should either show the concentrations are less than 10 percent of the values in Table 2, Column 1 or use other methods discussed (e.g., computerized modeling described in Regulatory Position C.2.e) to demonstrate compliance.
These licens ees include radiographers, well loggers, and other users of sealed sources. These licensees need not take any ac tions to demonstrate compliance with the constraint on releases of airborne radioactive materials to the environment.


The "sum of the fractions" technique can be used to assess effluents that contain multiple radionuclides or multiple release points or both.  With this technique, if radionuclides a , b , and c are present in concentrations C a , C b , and C c and if the applicable effluent concentrations in Table 2, Column 1, in Appendix B to 10 CFR Part 20 are EC a , EC b, and EC c , respectively, satisfying the inequality below is sufficient to demonstrate that the licensee has met the constraint.  For the situation of multiple release points, licensees should consider using only the highest concentration of a particular radionuclide among all release points.
CONSTRAINTS
A dose limit derived from a basic radiation protec tion standard is the upper acceptable bound of radiation dose and is needed to protect the health and safety of in dividuals;
a limit is a value not to be exceeded.


1.0<++c c b b a a EC C EC C EC C  Note:  If the radionuclides evaluated are only those limited by the Stochastic ALI, then the inequality condition can be revised to "< 0.2."
Such lim its should be set with the assumption that effluent re leases associated with licensed activities would result in doses to the public that are substantially below that val ue. Such limits are approached only under unusual cir cumstances, and only for a small fraction of the exposed population.
  The licensee may develop an annual dose estimate from this method by multiplying the calculated ratio by 1.0 mSv (100 mrem, or 0.5 mSv [50 mrem] if only considering those radionuclides limited by the Stochastic ALI), which, as previously discussed, is the dose estimated from exposure to radionuclide concentrations in Table 2, Column 1, in Appendix B to 10 CFR Part 20.


b. To demonstrate that it meets the constraint on airborne emissions, the licensee should show, by measurement or calculation, that the annual average concentration of airborne radioactive material released to the environment (including radionuclides that are limited by submersion dose) does not exceed 10 percent of the values in Table 2, Column 1, in Appendix B to  
A constraint is a dose value above which li censees are required to report to NRC and to take cor rective actions to lower the dose below the constraint val ue. Enforcement action would only occur if a licensee fails to report an exceedance of the constraint or fails to take appropriate and timely corrective actions.
10 CFR Part 20.  The following formula demonstrates this technique:
, V fQ C=  where:  C = average airborne concentration at the receptor (curies per cubic meter or microcuries per milliliter), 
f = fraction of the time the wind blows toward the receptor of interest (dimensionless), 
Rev. 1 of RG 4.20, Page 7 Q =  effluent release rate (curies per second), and V =  volumetric flow rate at the point of release (cubic meters per second (m
3/s)).  Default values of f and V have been developed for NCRP Report No. 123, "Screening Models for Releases of Radionuclides to Atmosphere, Surface Water, and Ground," dated January 22, 1996 (Ref. 14), and may be used if needed.  Default values for f are 0.25 for long- and intermediate-term releases greater than 24 hours in duration and 1 for "puff" releases or releases of less than 24 hours.  The default value for V is 0.3 m 3/s.  Site-specific values for these parameters should be used when available.  Multiple radionuclides or release points or both should also be addressed using the "sum of fraction" technique previously discussed in Regulatory Position C.2.a.


If the radionuclides in effluent exclude those limited by submersion dose, the licensee can demonstrate meeting the constraint if the annual average concentration of airborne radioactive material released to the environment does not exceed 20 percent of the values in Table 2, Column 1, in Appendix B to 10 CFR Part 20.  Alternatively, the licensee can use other methods discussed (e.g., computerized modeling described in Regulatory Position C.2.e) to demonstrate compliance.
C. REGULATORY
POSITION


c. Licensees may also use site-specific meteorological data to generate more realistic estimations of airborne radionuclide concentrations at the receptor.  If site-specific data are available, the following equation can be used to estimate the airborne concentration of radionuclides:
===1. CONSTRAINT ===
, Q Q C=  where '/Q(chi-bar over Q prime or simply chi over Q) is the average annual atmospheric dispersion factor in seconds per cubic meter, and C and Q are as defined in Regulatory Position C.2.
ON ENVIRONMENTAL
AIR EMISSIONS
The following methods are acceptable to the NRC staff for determining the dose to members of the public from exposure to airborne radioactive material that has been released to the environment by NRC licensees oth er than power reactors.


====b. The atmospheric ====
Licensees should choose a moni toring period (e.g., a year, month, or quarter) to demon strate compliance with the airborne emissions constraint in accordance with 10 CFR 20.1101(d).  
'/Qat a receptor location could be determined using several different types of meteorological models. The most common is the straight-line Gaussian model, which is conservative and the basis of meteorological dispersion estimates in most common radionuclide transport and dispersion programs.  Regulatory Guide 1.111, "Methods for Estimating Atmospheric Transport and Dispersion of Gaseous Effluents in Routine Releases from Light-Water-Cooled Reactors" (Ref. 15), describes methods acceptable to the NRC staff for calculation models and assumptions for estimating atmospheric transport and dispersion of airborne emissions from power reactors.  These methods would be acceptable for nonreactor facilities that use this guide.
For most licens ees, the monitoring period will be one year.  1.1 Licensees who (1) operate a nuclear power reac tor subject to 10 CFR 50.34a or (2) possess and use radio nuclides only in the form of sealed sources need not take any actions to demonstrate compliance with the constraint.


Licensees can also use more complex models, such as Lagrangian puff dispersion models; however, unless they already have a model in place, the additional effort and expense of implementation would not likely provide a significant benefit.
4.20-2
1.2 Radioactive materials in sealed containers that remain unopened and have not leaked during the assess ment period need not be included in the calculations.


Concentrations determined in this manner should be compared to either 10 percent or 20 percent of the applicable effluent concentrations in Table 2, Column 1, in Appendix B to 10 CFR Part 20 similar to the method presented in Regulatory Position C.2.a.  However, in the case of multiple release points, the concentrations of individual radionuclides (or dose) derived from individual Rev. 1 of RG 4.20, Page 8  release points would be summed to determine a total concentration (or dose) after dispersion to a receptor.  Also, if the radionuclides in effluent include a mixture of those limited by the stochastic ALI and submersion dose, the licensee should either compare to 10 percent of the concentrations presented in Table 2, Column 1 or use other methods discussed (e.g., computerized modeling described in Regulatory Position C.2.e) to demonstrate compliance.
Ex amples of sealed containers would include radiopharma ceuticals in unopened manufacturers packages and materials in undamaged shipping containers.


d. Another method that the NRC staff considers acceptable for demonstrating compliance with the dose constraint in 10 CFR 20.1101(d) appears in the worksheets in either NCRP Commentary No. 3, "Screening Techniques for Determining Compliance with Environmental Standards," issued January 1989 (with an addendum in October 1989) (Ref. 16); EPA 520/1-89-002, "A
Indepen dent spent fuel storage canisters that do not have vents to the atmosphere may also be considered sealed containers.
Guide for Determining Compliance with the Clean Air Act Standards for Radionuclide Emissions from NRC-Licensed and Non-DOE Federal Facilities," Revision 2, issued October 1989 (Ref. 17); or NCRP Report No. 123 (Ref. 14). 
e. Another method that the NRC staff considers acceptable for demonstrating compliance with 10 CFR 20.1101(d) is the use of computer codes.  The computer code COMPLY assesses dose from airborne releases using varying amounts of site-specific information in four screening levels.  In Level 1, the simplest level, only the quantity of radioactive material possessed during the monitoring period is entered.  The calculations are based on generic parameters.  Level 4 produces a more representative dose estimate and provides for a more complete treatment of air dispersion by requiring the greatest amount of site-specific information.  Licensees that do not pass at the lowest level in COMPLY must move to the next higher level until they can demonstrate compliance.  If licensees fail to show compliance at Level 4, they should consider the possibility that their air emissions do not meet the constraint.  The bases for the methods in COMPLY appear in EPA 520/1-89-003, "Users Guide for the COMPLY Code," Revision 2, issued October 1989 (Ref. 18), and in EPA 520/1-89-002 (Ref. 17). 
If a licensee has been granted permission to use dosimetry models or dose conversion coefficients other than those described in ICRP Publication Nos. 26 and 30 (e.g., ICRP Publication No. 68, "Dose Coefficients for Intake of Radionuclides by Workers" (Ref. 19)), it may also use the computer code CAP88 PC.  The version of CAP88 PC used should either incorporate the approved guidance methods or be conservative relative to the approved guidance.  COMPLY and CAP88 PC, together with their documentation, are available for download from the EPA Web site at http://www.epa.gov/radiation/assessment/software.  If the licensee uses a computer code other than those listed above to demonstrate that it meets the constraint, it should be prepared to demonstrate that the code has received appropriate software quality assurance such as that expected for commonly accepted computer programs.  Licensees should perform and document software quality assurance if they develop their own programs or use spreadsheets for calculations.


3. Reports to the NRC If a Constraint Has Been Exceeded If measurements or calculations determine that a facility has exceeded the constraint of 10 mrem (0.1 mSv) per year to the member of the public likely to receive the highest dose, the licensee must send a report to the NRC within 30 days after learning of the excess dose, as required by 10 CFR 20.2203(a)(2)(vi), and must describe the extent of the exposure in accordance with
1.3 Effluents from patients need not be included if compliance with the constraint is demonstrated by using an inventory approach.
10 CFR 20.2203(b)(1).  The report should include the following information: 
(1) an estimate of the dose, including the methods used to perform the estimate,  (2) the concentrations of the radioactive material released, Rev. 1 of RG 4.20, Page 9  (3) the cause of the elevated concentrations in effluents,  (4) the corrective steps taken or planned to ensure against a recurrence, and  (5) a schedule for completing the corrective steps.


The report should contain enough information to allow the NRC staff to verify the measurements or calculations.  It should be sent to the U.S. Nuclear Regulatory Commission, Document Control Desk, Washington, DC 20555-0001, with a copy to the appropriate NRC regional office listed in Appendix D, "United States Regulatory Commission Regional Offices," to 10 CFR Part 20.  Alternative means of submission include hand delivery to the NRC offices at 11555 Rockville Pike, Rockville, MD, and, where practicable, electronic submission.
If compliance with the constraint is demonstrated by using measured or calculated con centrations of radioactive materials in the environment, the contribution from patients is considered insignifi cant and need not be considered.


Rev. 1 of RG 4.20, Page 10 
1.4 If it can be determined that some detected mate rials did not result from licensed activities of the licens ee, only radioactive materials from the licensed activity need be considered.


==D. IMPLEMENTATION==
Materials that are windblown from other facilities need not be considered.
The purpose of this section is to provide information to applicants and licensees regarding the NRC's plans for using this regulatory guide.  The NRC does not intend or approve any imposition or backfit in connection with its issuance.


In some cases, applicants or licensees may propose or use a previously established acceptable alternative method for complying with specified portions of the NRC's regulations. Otherwise, the methods described in this guide will be used in evaluating compliance with the applicable regulations for license applications, license amendment applications, and amendment request
1.5 In determining the member of the public likely to receive the highest dose from airborne radioactive material released from licensed operations to the envi ronment, licensees need not consider nonresidents with in the facility boundary.


====s.     ====
===2. CALCULATION ===
Rev. 1 of RG 4.20, Page 11 REFERENCES
OF DOSE TO THE MEMBER OF THE PUBLIC LIKELY TO RECEIVE THE HIGHEST DOSE FROM AIR EFFLUENTS
1  1. 10 CFR Part 20, "Standards for Protection against Radiation," U.S. Nuclear Regulatory Commission, Washington, DC.
In demonstrating compliance with 10 CFR 20.1101(d), licensees should determine whether there have been any facility or design modifications, increases in radionuclide inventories, or operational changes; li censees should determine whether any of these factors resulted in variations to airborne emissions since the last monitoring period. If licensee operations have not changed, the review of licensed operations and demon stration of compliance with the constraint will be rela tively straightforward.


2. Atomic Energy Act of 1954, as amended, Public Law 83-703, 68 Stat. 919, August 30, 1954.
Any of the following methods are acceptable for demonstrating compliance with 10 CFR 20.1101(d). 
2.1 The simplest screening technique is to assume that the air concentration at the receptor is equal to the air concentration measured at the point of release. This is analogous to using Appendix B to 10 CFR Part 20 to demonstrate compliance with the dose limits in Part 20.  2.2 To demonstrate compliance with the constraint on air emissions, the licensee should demonstrate, by measurement or calculation, that the annual average concentration of airborne radioactive material released to the environment does not exceed 20% of the values in Column 1 of Table 2 in Appendix B to 10 CFR Part 20. The following formula demonstrates this technique.


3. Clean Air Act of 1970, as amended, Public Law 91-604, 84 Stat. 1676, 1970.
C N V Where: C =Average air concentration at the receptor (Ci/m 3 or IiCi/ml)f = Fraction of the time the wind blows toward the receptor of interest (dimensionless) (For a single "puff" release, the appropri ate value is 1.) Q = Effluent release rate (Ci/s) V = Volumetric flow rate at the point of release (m 3/s) The "sum of the fractions" technique should be used to assess compliance for effluents containing multiple ra dionuclides.


2
With this technique, if radionuclides "a," "b," and "c" are present in concentrations Ca, Cb, and Cc, and if the applicable effluent concentrations in Column 1 of Table 2 in Appendix B to 10 CFR Part 20 are ECa, ECb, and ECc respectively, satisfying the following in equality is sufficient to demonstrate compliance with the constraint.
4. 40 CFR Part 61, "National Emission Standards for Hazardous Air Pollutants," U.S. Environmental Protection Agency, Washington, DC.


5. Regulatory Guide 8.10, "Operating Philosophy for Maintaining Occupational Radiation Exposures As Low As Is Reasonably Achievable," U.S. Nuclear Regulatory Commission, Washington, DC.
C-- + + < 0.2 TC- TEC, EC, 2.3 Additional methods acceptable to the NRC staff for demonstrating compliance with 10 CFR 20.1101(d)
can be found in the worksheets contained in either NCRP Commentary No. 3, "Screening Techniques for Determining Compliance with Environmental Stan dards," 2 or EPA 520/1-89-002, "A Guide for Deter mining Compliance with the Clean Air Act Standards for Radionuclide Emissions from NRC-Licensed and Non DOE Federal Facilities" (Revision
2).3 2.4 Another method that is acceptable to the NRC staff for demonstrating compliance with 10 CFR 20.1101(d)
is the use of the computer code COMPLY.  COMPLY was developed by the EPA to assess doses by using site-specific information in the determination of dose. COMPLY has four screening levels. In Level 1, the simplest level, only the quantity of radioactive material possessed during the monitoring period is entered. The calculations are based on generic parameters.


6. Regulatory Guide 8.37, "ALARA Levels for Effluents from Materials Facilities," U.S. Nuclear Regulatory Commission, Washington, DC.
Level 4 produces a more representative dose estimate by provid ing for more complete treatment of air dispersion by re quiring site-specific information.


7. Regulatory Guide 4.21, "Minimization of Contamination and Radioactive Waste Generation: Life-Cycle Planning," U.S. Nuclear Regulatory Commission, Washington, DC.
It is expected that all 2 NCRP Commentary No. 3 was published in January 1989 and the ad dendum was published in October 1989. Copies may be purchased from the National Council on Radiation Protection and Measure ments, NCRP Publications, 7910 Woodmont Avenue, Bethesda, MD 20814.  3 Copies may be obtained from the U.S. Environmental Protection Agency, Office of Radiation and Indoor Air, 401 M Street SW, Wash ington, DC 20460.4.20-3 NRC licensees will be able to demonstrate compliance at one of the four levels. The basis for the compliance mea sures in COMPLY are contained in "Background Infor mation Document:
Procedures Approved for Demon strating Compliance with 40 CFR Part 61, Subpart I" (EPA 520/1-89-001, October 1989).4 If a computer code other than those listed above is used to demonstrate compliance with the constraint, the licensee should be prepared to demonstrate that the code has undergone verification and validation (V & V). For more information on software quality assurance in cluding V & V, licensees may refer to NUREG/ BR-0167, "Software Quality Assurance Program and Guidelines." This document can be purchased from the U.S. Government Printing Office, PO. Box 37082, Wash ington, DC 20402-9328.


8. NCRP Report No. 127, "Operational Radiation Safety Program," National Council on Radiation Protection and Measurements, Bethesda, MD, June 1998.
3. REPORTS TO NRC IF CONSTRAINT
HAS BEEN EXCEEDED If the constraint of 10 mrem (0.1 mSv) per year to the member of the public likely to receive the highest dose has been exceeded as determined by measurement or calculation, 10 CFR 20.2203(a)(2)(vi)
requires licens ees to send a report to the NRC within 30 days after 4Copies of the EP


3  9. NCRP Statement No. 8, "The Application of ALARA for Occupational Exposures," National Council on Radiation Protection and Measurements, Bethesda, MD, June 8, 1999.
==A. Background Information==
Document and the COM PLY computer code with its Users Guide may be obtained by writing to the Center for Federal Guidance and Air Standards
(6602J), Office of Radiation and Indoor Air, Environmental Protection Agency, Wash ington, DC 20460. It can also be downloaded from the Technology "li*ansfer Network (TTN) Electronic Bulletin Board under the Office of Radiation and Indoor Air technical information area. The number for the TTN is (919)541-5742.


10. SECY-01-048, "Processes for Revision of 10 CFR Part 20 regarding Adoption of ICRP Recommendations on Occupational Dose Limits and Dosimetric Models and Parameters," U.S. Nuclear Regulatory Commission, Washington, DC, August 2, 2001. ML011580374
In addition, EPA has pages on the World Wide Web as another mechanism to provide computer codes to licensees.
11. 10 CFR Part 50, "Domestic Licensing of Production and Utilization Facilities," U.S. Nuclear Regulatory Commission, Washington, DC.


12. Regulatory Guide 4.16, "Monitoring and Reporting Radioactivity in Releases of Radioactive Materials in Liquid and Gaseous Effluents from Nuclear Fuel Processing and Fabrication Plants and Uranium Hexafluoride Production Plants," U.S. Nuclear Regulatory Commission, Washington, DC.
The addresses are ttnftp.rtpnc.epa.gov and ttnwww.rtpnc.epa.gov.


1  Publicly available NRC published documents are available electronically through the NRC Library on the NRC's public Web site at: http://www.nrc.gov/reading-rm/doc-collections/.  The documents can also be viewed on-line or printed for a fee in the NRC's Public Document Room (PDR) at 11555 Rockville Pike, Rockville, MD; the mailing address is USNRC PDR, Washington, DC 20555; telephone 301-415-4737 or (800) 397-4209; fax (301) 415-3548; and e-mail pdr.resource@nrc.gov.  2  EPA Library Services Web page: http://www.epa.gov/libraries/library_services.html or National Service Center for Environmental Publications (NSCEP) - EPA's Gateway to Free Digital & Paper Publications: http://www.epa.gov/nscep/
learning of the dose in excess of the constraint, and 10 CFR 20.2203(b)(1)  
  3  The National Council on Radiation Protection and Measurements (NCRP)   Could be available online http://www.ncrponline.org/Publications/Publications.html
requires licensees to describe the ex tent of exposure.
] 
Rev. 1 of RG 4.20, Page 12 
13. ANSI/HPS N13.1-1999, "Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities," American National Standards Institute/Health Physics Society, McLean, VA, 1999.


4 14. NCRP Report No. 123, "Screening Models for Releases of Radionuclides to Atmosphere, Surface Water, and Ground," National Council on Radiation Protection and Measurements, Bethesda, MD, January 22, 1996.
The report should include the follow ing information.


5  15. Regulatory Guide 1.111, "Methods for Estimating Atmospheric Transport and Dispersion of Gaseous Effluents in Routine Releases from Light-Water-Cooled Reactors," U.S. Nuclear Regulatory Commission, Washington, DC.
"* An estimate of the dose "* The concentrations of the radioactive material released "* The cause of the elevated concentrations in effluents
"* The corrective steps taken or planned to ensure against a recurrence
"* A schedule for completing the corrective steps. The report should contain enough information to allow the NRC staff to verify the calculations.


16. NCRP Commentary No. 3, "Screening Techniques for Determining Compliance with Environmental Standards," National Council on Radiation Protection and Measurements, Bethesda, MD, January 1989 (with October 1989 addendum).
The report should be sent to the U.S. Nuclear Regu latory Commission, Document Control Desk, Washing ton, DC 20555-0001, with a copy to the appropriate NRC Regional Office listed in Appendix D to 10 CFR Part 20.
17. EPA 520/1-89-002, "A Guide for Determining Compliance with the Clean Air Act Standards for Radionuclide Emissions from NRC-Licensed and Non-DOE Federal Facilities," Revision 2, U.S. Environmental Protection Agency, Washington, DC, October 1989.


18. EPA 520/1-89-003, "Users Guide for the COMPLY Code," Revision 2, U.S. Environmental Protection Agency, Washington, DC, October 1989.
==D. IMPLEMENTATION==
 
The purpose of this section is to provide informa tion to applicants and licensees regarding the NRC staff's plans for using this guide.  Except in those cases in which an applicant proposes an acceptable alternative method for complying with specified portions of the NRC's regulations, the meth ods described in this guide will be used in the evaluation of applications for new licenses, license renewals, or li cense amendments and for evaluating compliance with 10 CFR Part 20.4.20-4 REGULATORY
19. ICRP Publication No. 68, "Dose Coefficients for Intakes of Radionuclides by Workers," Annals of the ICRP, Volume 224(4), International Commission on Radiological Protection, Ottawa, Ontario, Canada.
ANALYSIS A separate regulatory analysis was not prepared for this regulatory guide. The regulatory analysis prepared for the amendments to 10 CFR Part 20, "Standards for Protection Against Radiation," provides the regulatory basis for this guide. A copy of this regulatory analysis is available, as an enclosure to SECY-95-133, for inspection or copying for a fee at the NRC Public Document Room, 2120 L Street NW, Washington, DC.4.20-5 Federal Recycling Program
 
) UNITED STATES NUCLEAR REGULATORY
6                                           
COMMISSION
4  Copies of American National Standards Institute (ANSI) standards may be purchased from ANSI, 1819 L Street, NW., Washington, DC 20036, on their Web site at http://webstore.ansi.org/; telephone (202) 293-8020; fax (202) 293-9287; or e-mail storemanager@ansi.org
WASHINGTON, DC 20555-0001 I FIRST CLASS MAIL POSTAGE AND FEES PAID USNRC PERMIT NO. G-67 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, $300 0 0 6i U.  0 w z_ C-) z_ a. z z .I z (: (6}}
. 5 The National Council on Radiation Protection and Measurements (NCRP)
    Could be available online http://www.ncrponline.org/Publications/Publications.html
  6  International Commission on Radiological Protection (ICRP) http://www.icrp.org/}}


{{RG-Nav}}
{{RG-Nav}}

Revision as of 18:21, 31 August 2018

(Draft Issued as DG-8016), Constraint on Release of Airborne Radioactive Materials to the Environment for Licensees Other than Power Reactors
ML003739525
Person / Time
Issue date: 12/31/1996
From:
Office of Nuclear Regulatory Research
To:
References
RG-4.20
Download: ML003739525 (7)
v • d • e


U.S. NUCLEAR REGULATORY

COMMISSION

REGULATORY

December 199 GUIDE OFFICE OF NUCLEAR REGULATORY

RESEARCH REGULATORY

GUIDE 4.20 (Draft issued as DG-8016) CONSTRAINT

ON RELEASES OF AIRBORNE RADIOACTIVE

MATERIALS

TO THE ENVIRONMENT

FOR LICENSEES

OTHER THAN POWER REACTORS

A. INTRODUCTION

In 10 CFR Part 20, "Standards for Protection Against Radiation," § 20.1302(b)

requires that: A licensee shall show compliance with the annual dose limit in § 20.1301 by (1) Demonstrating by measurement or calculation that the total effective dose equivalent to the individual likely to receive the highest dose from the licensed operation does not exceed the annual dose limit; or (2) Demonstrat ing that (i) The annual average concentrations of ra dioactive material released in gaseous and liquid effluents at the boundary of the unrestricted area do not exceed the values specified in Table 2 of Appen dix B to Part 20; and (ii) If an individual were contin uously present in an unrestricted area, the dose from external sources would not exceed 0.002 rem (0.02 mSv) in an hour and 0.05 rem (0.5 mSv) in a year. In addition, 10 CFR 20.1101(d)

requires that: To implement the ALARA [as low as is reasonably achievable]

requirements of § 20.1101(b), and not withstanding the requirements in § 20.1301 of this part, a constraint on air emissions of radioactive ma terial to the environment, excluding radon-222 and its daughters, shall be established by licensees other USNRC REGULATORY

GUIDES Regulatory Guides are issued to describe and make available to the public such informa tion as methods acceptable to the NRC staff for implementing specific pals of the Com mission's regulations, techniques used by the staff in evaluating specific problems or pos tulated accidents, and data needed by the NRC staff in its review of applications for per mits and licenses Regulatory guides are not substitutes for regulations, and compliance with them is not required.

Methods and solutions different from Itho sat out in the guides will be acceptable if they provide a basis for the findings requisite to the issuance or con tinuance of a permit or license by the Commission.

This guide was issued after consideration of comments received from the public. Com ments and suggestions for improvements in these guides are encouraged at all times, and guides will be revised, as approprate, to accommodate comments and to reflect new in formation or experience.

Written comments may be submitted to the Rules Review and Directives Branch, DFIPS. ADM, U S Nuclear Regulatory Commission, Washington, DC 20555-0001.

than those subject to 10 CFR 50.34a, such that the individual member of the public likely to receive the highest dose will not be expected to receive a total effective dose equivalent in excess of 10 mrem (0.1 mSv) per year from these emissions.

If a licensee subject to this requirement exceeds this dose con straint, the licensee shall report the exceedance as provided in 10 CFR 20.2203 and promptly take ap propriate corrective action to ensure against recurrence.

This regulatory guide provides guidance on meth ods acceptable to the NRC staff for compliance with the constraint on air emissions to the environment.

If addi tional significant comments are received in the first year following its issuance, the staff will revise the guide as ap propriate.

Guidance on ALARA programs can be found in other regulatory guides. Although these guides deal primarily with occupational exposure and may be specif ic to one type of licensee, they contain programmatic in formation that may be useful to all licensees.

These guides are: 0 Regulatory Guide 8.10, "Operating Philosophy for Maintaining Occupational Radiation Exposures As Low As Is Reasonably Achievable." This guide de lineates the components of an ALARA program.The guides are issued in the following ten broad divisions:

1. Power Reactors 2. Research and Test Reactors 3. Fuels and Matenels Facilities

4. Environental and Siting 5. Materials and Plant Protection

& Products 7. Transportation S Occupational Health 9g Antitrust and Financial Review 10 General Single copies of regulatory guides may be obtained free of charge by writing the Office of Adminstration, Attention:

Distribution and Services Section, U.S. Nuclear leguloy Commission.

Washington, DC 20655-0001;

or by ftax at (301)415-2280

Issued guides may also be purchased from the National Technical Information Service onr a standing order basis. Details on this service may be obtained by writing NTIS. 5285 Port Royal Road, Springfield, VA 22161.

"* Regulatory Guide 8.18, "Information Relevant to Ensuring that Occupational Radiation Exposures at Medical institutions Will Be As Low As Reasonably Achievable." " Regulatory Guide 8.31, "Information Relevant to Ensuring that Occupational Radiation Exposures at Uranium Mills Will Be As Low As Is Reasonably Achievable." "* Regulatory Guide 8.37, "ALARA Levels for Efflu ents from Materials Facilities." 0 Regulatory Guide 10.8, "Guide for the Preparation of Applications for Medical Use Programs." Sec tion 1.3 and Appendix G deal specifically with ALARA programs for medical facilities.

In addition, further information can be found in Re vision 1 to NUREG-0267, "Principles and Practices for Keeping Occupational Radiation Exposures As Low As Reasonably Achievable" (October 1982).1 The information collections contained in this regu latory guide are covered by the requirements of 10 CFR Part 20, which were approved by the Office of Manage ment and Budget, approval number 3150-0014.

The NRC may not conduct or sponsor, and a person is not re quired to respond to, a collection of information unless it displays a currently valid OMB control number.

B. DISCUSSION

The dose limits in 10 CFR Part 20 are based on limit ing dose to an acceptably low level of risk to the exposed individual.

However, any radiation exposure may carry some risk. Thus, the NRC requires licensees to take ac tions, to the extent practicable, utilizing procedures and engineering controls to further reduce risk below the lev els implicit in the dose limits in keeping with the princi ple that exposures should be as low as is reasonably achievable.

This is the goal and purpose for radiation protection programs.

In order to achieve this goal, li censees must control the way radioactive material is han dled from receipt through disposal.

ALARA Components of an effective radiation protection program, as required by 10 CFR 20.1101, include radi ation exposure control, written procedures and policies, control of radioactive materials, radioactive contamina tion control, radioactive waste management, training, program reviews, and audits. 'Copies are available for purchase from the U.S. Government Printing Office, PO. Box 37082, Washington, DC 20013-7082, telephone

(202) 512-2249;

or from the National Technical Information Service by writing NTIS at 5285 Port Royal Road, Springfield, VA 22161. Co pies are available for inspection or copying for a fee from the NRC Pub lic Document Room at 2120 L Street NW., Washington, DC; the PDR's mailingaddress is Mail StopLL-6, Washington, DC20555; telephone

(202)634-3273;

fax (202)634-3343.

The NRC staff examines licensee programs to deter mine whether they are in compliance with the require ments of 10 CFR Part 20. This guide addresses only a part of a licensee's overall radiation protection program.

Specifically, it addresses methods for demonstrating compliance with the constraint on releases of airborne radioactive materials to the environment.

In addition to controlling doses from the releases of airborne radioac tive materials to the environment, licensees must imple ment a radiation protection program that controls liquid effluents and dose rates in unrestricted areas. Many NRC licensees possess source, byproduct, or special nuclear material in a form that would not cause doses to members of the public from releases of airborne radioactive material to the environment.

These licens ees include radiographers, well loggers, and other users of sealed sources. These licensees need not take any ac tions to demonstrate compliance with the constraint on releases of airborne radioactive materials to the environment.

CONSTRAINTS

A dose limit derived from a basic radiation protec tion standard is the upper acceptable bound of radiation dose and is needed to protect the health and safety of in dividuals;

a limit is a value not to be exceeded.

Such lim its should be set with the assumption that effluent re leases associated with licensed activities would result in doses to the public that are substantially below that val ue. Such limits are approached only under unusual cir cumstances, and only for a small fraction of the exposed population.

A constraint is a dose value above which li censees are required to report to NRC and to take cor rective actions to lower the dose below the constraint val ue. Enforcement action would only occur if a licensee fails to report an exceedance of the constraint or fails to take appropriate and timely corrective actions.

C. REGULATORY

POSITION

1. CONSTRAINT

ON ENVIRONMENTAL

AIR EMISSIONS

The following methods are acceptable to the NRC staff for determining the dose to members of the public from exposure to airborne radioactive material that has been released to the environment by NRC licensees oth er than power reactors.

Licensees should choose a moni toring period (e.g., a year, month, or quarter) to demon strate compliance with the airborne emissions constraint in accordance with 10 CFR 20.1101(d).

For most licens ees, the monitoring period will be one year. 1.1 Licensees who (1) operate a nuclear power reac tor subject to 10 CFR 50.34a or (2) possess and use radio nuclides only in the form of sealed sources need not take any actions to demonstrate compliance with the constraint.

4.20-2

1.2 Radioactive materials in sealed containers that remain unopened and have not leaked during the assess ment period need not be included in the calculations.

Ex amples of sealed containers would include radiopharma ceuticals in unopened manufacturers packages and materials in undamaged shipping containers.

Indepen dent spent fuel storage canisters that do not have vents to the atmosphere may also be considered sealed containers.

1.3 Effluents from patients need not be included if compliance with the constraint is demonstrated by using an inventory approach.

If compliance with the constraint is demonstrated by using measured or calculated con centrations of radioactive materials in the environment, the contribution from patients is considered insignifi cant and need not be considered.

1.4 If it can be determined that some detected mate rials did not result from licensed activities of the licens ee, only radioactive materials from the licensed activity need be considered.

Materials that are windblown from other facilities need not be considered.

1.5 In determining the member of the public likely to receive the highest dose from airborne radioactive material released from licensed operations to the envi ronment, licensees need not consider nonresidents with in the facility boundary.

2. CALCULATION

OF DOSE TO THE MEMBER OF THE PUBLIC LIKELY TO RECEIVE THE HIGHEST DOSE FROM AIR EFFLUENTS

In demonstrating compliance with 10 CFR 20.1101(d), licensees should determine whether there have been any facility or design modifications, increases in radionuclide inventories, or operational changes; li censees should determine whether any of these factors resulted in variations to airborne emissions since the last monitoring period. If licensee operations have not changed, the review of licensed operations and demon stration of compliance with the constraint will be rela tively straightforward.

Any of the following methods are acceptable for demonstrating compliance with 10 CFR 20.1101(d).

2.1 The simplest screening technique is to assume that the air concentration at the receptor is equal to the air concentration measured at the point of release. This is analogous to using Appendix B to 10 CFR Part 20 to demonstrate compliance with the dose limits in Part 20. 2.2 To demonstrate compliance with the constraint on air emissions, the licensee should demonstrate, by measurement or calculation, that the annual average concentration of airborne radioactive material released to the environment does not exceed 20% of the values in Column 1 of Table 2 in Appendix B to 10 CFR Part 20. The following formula demonstrates this technique.

C N V Where: C =Average air concentration at the receptor (Ci/m 3 or IiCi/ml)f = Fraction of the time the wind blows toward the receptor of interest (dimensionless) (For a single "puff" release, the appropri ate value is 1.) Q = Effluent release rate (Ci/s) V = Volumetric flow rate at the point of release (m 3/s) The "sum of the fractions" technique should be used to assess compliance for effluents containing multiple ra dionuclides.

With this technique, if radionuclides "a," "b," and "c" are present in concentrations Ca, Cb, and Cc, and if the applicable effluent concentrations in Column 1 of Table 2 in Appendix B to 10 CFR Part 20 are ECa, ECb, and ECc respectively, satisfying the following in equality is sufficient to demonstrate compliance with the constraint.

C-- + + < 0.2 TC- TEC, EC, 2.3 Additional methods acceptable to the NRC staff for demonstrating compliance with 10 CFR 20.1101(d)

can be found in the worksheets contained in either NCRP Commentary No. 3, "Screening Techniques for Determining Compliance with Environmental Stan dards," 2 or EPA 520/1-89-002, "A Guide for Deter mining Compliance with the Clean Air Act Standards for Radionuclide Emissions from NRC-Licensed and Non DOE Federal Facilities" (Revision

2).3 2.4 Another method that is acceptable to the NRC staff for demonstrating compliance with 10 CFR 20.1101(d)

is the use of the computer code COMPLY. COMPLY was developed by the EPA to assess doses by using site-specific information in the determination of dose. COMPLY has four screening levels. In Level 1, the simplest level, only the quantity of radioactive material possessed during the monitoring period is entered. The calculations are based on generic parameters.

Level 4 produces a more representative dose estimate by provid ing for more complete treatment of air dispersion by re quiring site-specific information.

It is expected that all 2 NCRP Commentary No. 3 was published in January 1989 and the ad dendum was published in October 1989. Copies may be purchased from the National Council on Radiation Protection and Measure ments, NCRP Publications, 7910 Woodmont Avenue, Bethesda, MD 20814. 3 Copies may be obtained from the U.S. Environmental Protection Agency, Office of Radiation and Indoor Air, 401 M Street SW, Wash ington, DC 20460.4.20-3 NRC licensees will be able to demonstrate compliance at one of the four levels. The basis for the compliance mea sures in COMPLY are contained in "Background Infor mation Document:

Procedures Approved for Demon strating Compliance with 40 CFR Part 61, Subpart I" (EPA 520/1-89-001, October 1989).4 If a computer code other than those listed above is used to demonstrate compliance with the constraint, the licensee should be prepared to demonstrate that the code has undergone verification and validation (V & V). For more information on software quality assurance in cluding V & V, licensees may refer to NUREG/ BR-0167, "Software Quality Assurance Program and Guidelines." This document can be purchased from the U.S. Government Printing Office, PO. Box 37082, Wash ington, DC 20402-9328.

3. REPORTS TO NRC IF CONSTRAINT

HAS BEEN EXCEEDED If the constraint of 10 mrem (0.1 mSv) per year to the member of the public likely to receive the highest dose has been exceeded as determined by measurement or calculation, 10 CFR 20.2203(a)(2)(vi)

requires licens ees to send a report to the NRC within 30 days after 4Copies of the EP

A. Background Information

Document and the COM PLY computer code with its Users Guide may be obtained by writing to the Center for Federal Guidance and Air Standards

(6602J), Office of Radiation and Indoor Air, Environmental Protection Agency, Wash ington, DC 20460. It can also be downloaded from the Technology "li*ansfer Network (TTN) Electronic Bulletin Board under the Office of Radiation and Indoor Air technical information area. The number for the TTN is (919)541-5742.

In addition, EPA has pages on the World Wide Web as another mechanism to provide computer codes to licensees.

The addresses are ttnftp.rtpnc.epa.gov and ttnwww.rtpnc.epa.gov.

learning of the dose in excess of the constraint, and 10 CFR 20.2203(b)(1)

requires licensees to describe the ex tent of exposure.

The report should include the follow ing information.

"* An estimate of the dose "* The concentrations of the radioactive material released "* The cause of the elevated concentrations in effluents

"* The corrective steps taken or planned to ensure against a recurrence

"* A schedule for completing the corrective steps. The report should contain enough information to allow the NRC staff to verify the calculations.

The report should be sent to the U.S. Nuclear Regu latory Commission, Document Control Desk, Washing ton, DC 20555-0001, with a copy to the appropriate NRC Regional Office listed in Appendix D to 10 CFR Part 20.

D. IMPLEMENTATION

The purpose of this section is to provide informa tion to applicants and licensees regarding the NRC staff's plans for using this guide. Except in those cases in which an applicant proposes an acceptable alternative method for complying with specified portions of the NRC's regulations, the meth ods described in this guide will be used in the evaluation of applications for new licenses, license renewals, or li cense amendments and for evaluating compliance with 10 CFR Part 20.4.20-4 REGULATORY

ANALYSIS A separate regulatory analysis was not prepared for this regulatory guide. The regulatory analysis prepared for the amendments to 10 CFR Part 20, "Standards for Protection Against Radiation," provides the regulatory basis for this guide. A copy of this regulatory analysis is available, as an enclosure to SECY-95-133, for inspection or copying for a fee at the NRC Public Document Room, 2120 L Street NW, Washington, DC.4.20-5 Federal Recycling Program

) UNITED STATES NUCLEAR REGULATORY

COMMISSION

WASHINGTON, DC 20555-0001 I FIRST CLASS MAIL POSTAGE AND FEES PAID USNRC PERMIT NO. G-67 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, $300 0 0 6i U. 0 w z_ C-) z_ a. z z .I z (: (6


Retrieved from "https://kanterella.com/w/index.php?title=Regulatory_Guide_4.20&oldid=1013552"