Existing Situations: Public Dose Limit and Optimization Through the Use of Reference Levels Philip Egidi U.S. Environmental Protection Agency Office of Radiation and Indoor Air Low-Level Waste Forum Alexandria, VA October 17, 2017

Usual Disclaimers Apply… This presentation is the opinion of the author only and does not represent EPA policy, regulation, or position. October 17, 2017

Premise Radiation protection is based on fundamental principles, based on science, derived over many decades at the international level. There are three basic principles that form the basis for regulation and control of radioactivity: Limitation Justification Optimization October 17, 2017

Hierarchy of organizations: Science forms the basis for recommendations UNSCEAR ICRP IAEA NAS NCRP ISCORS FEDERAL AGENCIES TRIBES CRCPD STATES COMPACTS Source: Lazo 2015/NEA October 17, 2017

Inter-Agency Steering Committee on Radiation Standards Technical staff meet semi-annually (at least) with the purpose of harmonizing and being consistent among agencies in their approach to radiation protection October 17, 2017

Policy is Not Based on Science Alone October 17, 2017 Source: Mossman 1999

ICRP 103 Framework “The Recommendations of the International Commission on Radiological Protection” ICRP Report 103 Published in 2007 Replaced Report 60, published in 1990 Replaced Report 26/30, published in 1977 Many US Regulations (e.g., NRC 10 CFR 20) based on ICRP 26/30 dosimetry Some DOE and EPA criteria based on ICRP Report 60 New dose coefficients from ICRP 103 in process October 17, 2017

ICRP 103 changes ICRP 60 (1990) based on activities that increased exposure (practices) and activities that reduced exposure (interventions) ICRP 103 (2007) based on planned, existing and emergency situations All exposures, including those from (TE)NORM, are within the scope of the system. The principles of justification and optimization apply universally to all exposures resulting from either planned, emergency or existing situations. Limitation applies only to planned situations. Exposure to natural sources presents particular problems due to the varied nature of exposure situations and large variations in activity concentrations in NORM and may occur not only to workers involved in processing industries but also to the public from exposures to products, by-products, residues and wastes. And radon! We shall see that many countries are using dose limits anyway. October 17, 2017

Optimization ICRP recommends optimization (ALARA) as the primary tool for radiation protection Uses dose constraints or reference levels set within bands of doses Bands of dose are based on multiples of 1 mSv (100 mrem), being the approximate level of annual global per caput radiation exposure from natural sources (excluding exposures from radon.) Optimization applied below the upper limit of the band Not an enforceable dose limit ICRP now recommends that optimization of radiation exposure is the primary tool for radiation protection for each of these exposure situations where dose constraints or reference levels set within bands of doses are bench marks which can be used to judge whether radiation protection has been optimized. Bands of dose are set for different situations that are based on multiples of 1 mSv, being the approximate level of annual global per caput radiation exposure from natural sources, excluding exposures from radon. October 17, 2017

Planned and existing situations ICRP 103 applies to all exposures to ionizing radiation from any source, regardless of size or origin. For (TE)NORM, either the source of the exposure or the pathways leading to doses received by individuals can be controlled by some reasonable means, or Report 103 is not applicable. Planned situations, such as for licensed activities: Use a dose limit Existing situations, such as at NORM/TENORM industries: Use a reference level Abandoned uranium mines are an existing situation. October 17, 2017

Existing Situations vs Planned Situations October 17, 2017 Source: Lecompte 2013

Existing Exposure Situations A situation that already exists when a decision on control has to be taken, including natural background radiation and residues from past practices that were operated outside the Commission’s recommendations NORM is an existing exposure situation (at least at first). Reference level In existing exposure situations, this represents the level of dose or risk, above which it is judged to be inappropriate to plan to allow exposures to occur, and below which optimization of protection should be implemented. The chosen value for a reference level will depend upon prevailing circumstances of the exposure under consideration. NO DOSE LIMIT FOR EXISTING SITUATIONS… October 17, 2017

Reference Level Implementation Reference levels for public exposure (as applies to TENORM) Reference levels expressed in effective doses shall be set in the range of 1 to 20 mSv (100 mrem to 2 rem) per year for existing exposure situations and 20 to 100 mSv (2 to 10 rem)(acute or annual) for emergency exposure situations. …(b) a reference level below 1 mSv (100 mrem) per year may be set, where appropriate, in an existing exposure situation for specific source-related exposures or pathways of exposure. …The reference levels set shall take account of the features of prevailing situations as well as societal criteria… …for exposures below or equal to 1 mSv (100 mrem) per year, general information on the level of exposure, without specific consideration of individual exposures… Reference levels for public exposure as referred to in Articles 7 and 101 1. Without prejudice to reference levels set for equivalent doses, reference levels expressed in effective doses shall be set in the range of 1 to 20 mSv per year for existing exposure situations and 20 to 100 mSv (acute or annual) for emergency exposure situations. 2. In specific situations, a reference level below ranges referred to in point 1 may be considered, in particular: (a) a reference level below 20 mSv may be set in an emergency exposure situation where appropriate protection can be provided without causing a disproportionate detriment from the corresponding countermeasures or an excessive cost; (b) a reference level below 1 mSv per year may be set, where appropriate, in an existing exposure situation for specific source-related exposures or pathways of exposure. 3. For the transition from an emergency exposure situation to an existing exposure situation, appropriate reference levels shall be set, in particular upon the termination of long-term countermeasures such as relocation. 4. The reference levels set shall take account of the features of prevailing situations as well as societal criteria, which may include the following: (a) for exposures below or equal to 1 mSv per year, general information on the level of exposure, without specific consideration of individual exposures; (b) in the range up to or equal to 20 mSv per year, specific information to enable individuals to manage their own exposure, if possible; (c) in the range up to or equal to 100 mSv per year, assessment of individual doses and specific information on radiation risks and on available actions to reduce exposures. October 17, 2017

ICRP 103 Dose limits Radon evaluated separately (ICRP 126, 2014) Public dose limit for planned situations is 1 mSv/y above background Effective dose Exemption level for NORM isotopes: 1 kBq/kg (~27 pCi/g) Radon evaluated separately (ICRP 126, 2014) There are other ICRP limits but will not discuss for brevity… Partial list of dose limits October 17, 2017

ICRP Report 126 on Radon The Commission recommends 300 Bq/m3 (8 pCi/L) as the upper value of the derived reference level for radon gas in dwellings. This equates to ~12mSv/y (1.2 rem) Derived reference levels relate to the annual mean concentration of radon in a building or location The Commission recommended a detriment-adjusted nominal risk coefficient for lung cancer in a mixed adult population of non-smokers and smokers of 8x10-10 per Bq/h/m3 for exposure to radon-222 gas in equilibrium with its progeny [5x10-4 per working level month (WLM)]. This is approximately twice the value used by the Commission in Publication 65 WHO stated that a national reference level for dwellings of 100 Bq/m3 is justified from a public health perspective, but recognized that this level cannot be implemented in many countries. October 17, 2017

US Public Dose Limits Presidential Radiation Protection Guidance for the Public (1960) 5 mSv/y (500 mR/y) whole body 1.7 mSv/y (170 mR/y) when source is not known 50 mSv/30y (5 rem/30s) years to gonads Specific organ doses (1961) NRC 10 CFR 20 1 mSv/y (100 mR/y) effective dose from the licensed operation EPA Indoor radon action level (recommendation) remains at 4 pCi/L October 17, 2017

NCRP Report 116 (1993) Public Dose Limits 1 mSv/y (100 mR/y) effective dose continuous exposure 5 mSv/y (500 mR/y) effective dose infrequent exposure 1.7 mSv/y (170 mR/y) when source is not known Remedial Action Limits for NORM 2 WLM (7 x 10-3 Jh/m3) 5 mSv/y (500 mrem/y) NCRP is updating this report and new recommendations expected soon… October 17, 2017

DOE Public dose limits DOE Order 458.1 Ch 2 (2011) 1 mSv/y (100 mR/y) effective dose 15 mSv/y (1.5 rem) lens of eye – equivalent dose 50 mSv/ ( 5 rem/y) skin and extremities – equivalent dose 5 mSv (500 mrem) with approval providing does not exceed 1 mSv/y averaged over 5 years. Includes TENORM from DOE operations ALARA applies Additional dose constraints… October 17, 2017

TENORM Is Not Regulated Like Other Radioactive Materials ICRP Principles are not regulations. Each country adopts their own regulations based on ICRP. ICRP basis for IAEA recommendations and standards. Most US radiation regulations fall under the Atomic Energy Act of 1946, et seq. TENORM however, is NOT captured by the Atomic Energy Act This makes for an uneven playing field with respect to worker safety, public health and environmental protection TENORM is mostly unintended and those who possess it often do not have the resources to properly manage it October 17, 2017

TENORM in the U.S. It is unclear at this time how new dose coefficients and dose limits will impact the TENORM sector No one agency regulates all public exposures, only those under their authority The US will likely retain dose limits for all regulated activities Emphasis will remain on Optimization (ALARA) Radon remains a difficult challenge States are primarily responsible for regulating TENORM Public awareness is increasing ICRP is not a regulatory body – these are principles that countries need to adopt into regulation. October 17, 2017

Summary ICRP is evaluating its approach to NORM/TENORM TG-76 report in process, 2017-2018 Existing situations may adopt reference bands Optimization within bands May result in relaxed radiation protection goals Planned situation would have dose limits plus optimization Many issues to address No final decision anticipated soon October 17, 2017

Contact information Philip Egidi Environmental Scientist Radiation Protection Division Office of Radiation and Indoor Air Washington, DC 202-343-9186 egidi.philip@epa.gov October 17, 2017