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EXISTING EXPOSURE SITUATIONS

• SCOPE
  
  1. The requirements for existing exposure situations in Section 5 apply to:
     1. Exposure due to contamination of areas by residual radioactive material deriving from:
        1. Past activities that were never subject to regulatory control or that were subject to regulatory control but not in accordance with the requirements of these Standards;
        2. A nuclear or radiological emergency, after an emergency has been declared to be ended (as required in para. 4.20).
     2. Exposure due to commodities, including food, feed, drinking water and construction materials, that incorporate radionuclides deriving from residual radioactive material as stated in para. 5.1(a).
     3. Exposure due to natural sources, including:
        1. ²²²Rn and its progeny and ²²⁰Rn and its progeny, in workplaces other than those workplaces for which exposure due to other radionuclides in the uranium decay chain or the thorium decay chain is controlled as a planned exposure situation, in dwellings and in other buildings with high occupancy factors for members of the public;
        2. Radionuclides of natural origin, regardless of activity concentration, in commodities, including food, feed, drinking water, agricultural fertilizer and soil amendments, and construction materials, and residual radioactive material in the environment;
        3. Materials, other than those stated in (c)(ii) above, in which the activity concentration of no radionuclide in either the uranium decay chain or the thorium decay chain exceeds 1 Bq/g and the activity concentration of 40K does not exceed 10 Bq/g;
        4. Exposure of aircrew and space crew to cosmic radiation.
• GENERIC REQUIREMENTS
  Requirement 47: Responsibilities of the government specific to existing exposure situations
  The government shall ensure that existing exposure situations that have been identified are evaluated to determine which occupational exposures and public exposures are of concern from the point of view of radiation protection.
  2. The government shall ensure that, when an existing exposure situation is identified, responsibilities for protection and safety are assigned and appropriate reference levels are established.
  3. The government shall include in the legal and regulatory framework for protection and safety (see Section 2) provision for the management of existing exposure situations. The government, in the legal and regulatory framework, as appropriate:
     1. Shall specify the exposure situations that are included in the scope of existing exposure situations;⁴⁹
     2. Shall specify the general principles underlying the protection strategies developed to reduce exposure when remedial actions and protective actions have been determined to be justified;⁵⁰
     3. Shall assign responsibilities for the establishment and implementation of protection strategies to the regulatory body and to other relevant authorities⁵¹ and, as appropriate, to registrants, licensees and other parties involved in the implementation of remedial actions and protective actions;
     4. Shall provide for the involvement of interested parties in decisions regarding the development and implementation of protection strategies, as appropriate.
  4. The regulatory body or other relevant authority assigned to establish a protection strategy for an existing exposure situation shall ensure that it specifies:
     1. The objectives to be achieved by means of the protection strategy;
     2. Appropriate reference levels.
  5. The regulatory body or other relevant authority shall implement the protection strategy, including:
     1. Arranging for evaluation of the available remedial actions and protective actions for achieving the objectives, and for evaluation of the efficiency of the actions planned and implemented;
     2. Ensuring that information is available to individuals subject to exposure on potential health risks and on the means available for reducing their exposures and the associated risks.
• PUBLIC EXPOSURE
  Scope
  
  6. The requirements in respect of public exposure in existing exposure situations (paras 5.7–5.23) apply to any public exposure arising from the situations specified in para. 5.1.
  
  Requirement 48: Justification for protective actions and optimization of protection and safety
  The government and the regulatory body or other relevant authority shall ensure that remedial actions and protective actions are justified and that protection and safety is optimized.
  7. The government and the regulatory body or other relevant authority shall ensure that the protection strategy for the management of existing exposure situations, established in accordance with paras 5.2 and 5.4, is commensurate with the radiation risks associated with the existing exposure situation; and that remedial actions or protective actions are expected to yield sufficient benefits to outweigh the detriments associated with taking them, including detriments in the form of radiation risks.⁵²
  8. The regulatory body or other relevant authority and other parties responsible for remedial actions or protective actions shall ensure that the form, scale and duration of such actions are optimized. While this optimization process is intended to provide optimized protection for all individuals subject to exposure, priority shall be given to those groups for whom the dose exceeds the reference level. All reasonable steps shall be taken to prevent doses from remaining above the reference levels. Reference levels shall typically be expressed as an annual effective dose to the representative person in the range of 1–20 mSv or other corresponding quantity, the actual value depending on the feasibility of controlling the situation and on experience in managing similar situations in the past.
  9. The regulatory body or other relevant authority shall periodically review the reference levels to ensure that they remain appropriate in the light of the prevailing circumstances.
  Requirement 49: Responsibilities for remediation of areas with residual radioactive material
  The government shall ensure that provision is made for identifying those persons or organizations responsible for areas with residual radioactive material; for establishing and implementing remediation programmes and post-remediation control measures, if appropriate; and for putting in place an appropriate strategy for radioactive waste management.
  10. For the remediation of areas with residual radioactive material deriving from past activities or from a nuclear or radiological emergency (para. 5.1(a)), the government shall ensure that provision is made in the framework for protection and safety for:
      1. The identification of those persons or organizations responsible for the contamination of areas and those responsible for financing the remediation programme, and the determination of appropriate arrangements for alternative sources of funding if such persons or organizations are no longer present or are unable to meet their liabilities;
      2. The designation of persons or organizations responsible for planning, implementing and verifying the results of remedial actions;
      3. The establishment of any restrictions on the use of or access to the areas concerned before, during and, if necessary, after remediation;
      4. An appropriate system for maintaining, retrieval and amendment of records that cover the nature and the extent of contamination; the decisions made before, during and after remediation; and information on verification of the results of remedial actions, including the results of all monitoring programmes after completion of the remedial actions.
  11. The government shall ensure that a strategy for radioactive waste management is put in place to deal with any waste arising from the remedial actions and that provision for such a strategy is made in the framework for protection and safety.
  12. The persons or organizations responsible for the planning, implementation and verification of remedial actions shall, as appropriate, ensure that:
      1. A remedial action plan, supported by a safety assessment, is prepared and is submitted to the regulatory body or other relevant authority for approval.
      2. The remedial action plan is aimed at the timely and progressive reduction of the radiation risks and eventually, if possible, at the removal of restrictions on the use of or access to the area.
      3. Any additional doses received by members of the public as a result of the remedial actions are justified on the basis of the resulting net benefit, including consideration of the consequent reduction of the annual dose.
      4. In the choice of the optimized remediation option:
         1. Radiological impacts on people and the environment are considered together with non-radiological impacts on people and the environment, and with technical, societal and economic factors;
         2. The costs of the transport and management of radioactive waste, the radiation exposure of and health risks to the workers managing the radioactive waste, and any subsequent public exposure associated with its disposal are all taken into account.
      5. A mechanism for public information is in place and interested parties are involved in the planning, implementation and verification of the remedial actions, including any monitoring following remediation.
      6. A monitoring programme is established and implemented.
      7. A system for maintaining adequate records relating to the existing exposure situation and to actions taken for protection and safety is in place.
      8. Procedures are in place for reporting to the regulatory body or other relevant authority on any abnormal conditions relevant to protection and safety.
  13. The regulatory body, in accordance with para. 2.29, or other relevant authority shall take responsibility, in particular for:
      1. Review of the safety assessment submitted by the responsible person or organization, approval of the remedial action plan and of any subsequent changes to the remedial action plan, and granting of any necessary authorization;
      2. Establishment of criteria and methods for assessing safety;
      3. Review of work procedures, monitoring programmes and records;
      4. Review and approval of significant changes to procedures or equipment that may have radiological environmental impacts or that may alter the exposure conditions for workers taking remedial actions or for members of the public;
      5. Where necessary, establishment of regulatory requirements for control measures following remediation.
  14. The person or organization responsible for carrying out the remedial actions:
      1. Shall ensure that the work, including management of the radioactive waste arising, is conducted in accordance with the remedial action plan;
      2. Shall take responsibility for all aspects of protection and safety, including the conduct of a safety assessment;
      3. Shall monitor the area regularly during the remediation so as to verify levels of contamination, to verify compliance with the requirements for radioactive waste management, and to enable any unexpected levels of radiation to be detected and the remedial action plan to be modified accordingly, subject to approval by the regulatory body or other relevant authority;
      4. Shall perform a radiological survey after completion of remedial actions to demonstrate that the end point conditions, as established in the remedial action plan, have been met;
      5. Shall prepare and retain a final remediation report and shall submit a copy to the regulatory body or other relevant authority.
  15. After the remedial actions have been completed, the regulatory body or other relevant authority:
      1. Shall review, amend as necessary and formalize the type, extent and duration of any post-remediation control measures already identified in the remedial action plan, with due consideration of the residual radiation risks.
      2. Shall identify the person or organization responsible for any post-remediation control measures.
      3. Shall, where necessary, impose specific restrictions for the remediated area to control:
         1. Access by unauthorized persons;
         2. Removal of radioactive material or use of such material, including its use in commodities;
         3. Future use of the area, including the use of water resources and its use for the production of food or feed, and the consumption of food from the area.
      4. Shall periodically review conditions in the remediated area and, if appropriate, shall amend or remove any restrictions.
  16. The person or organization responsible for post-remediation control measures shall establish and maintain, for as long as required by the regulatory body or other relevant authority, an appropriate programme, including any necessary provision for monitoring, to verify the long term effectiveness of the completed remedial actions for areas in which controls are required after remediation.
  17. For those areas with long lasting residual radioactive material, in which the government has decided to allow habitation and the resumption of social and economic activities, the government, in consultation with interested parties, shall ensure that arrangements are in place, as necessary, for the continuing control of exposure with the aim of establishing conditions for sustainable living, including:
      1. Establishment of reference levels for protection and safety that are consistent with day to day life;
      2. Establishment of an infrastructure to support continuing ‘self-help protective actions’ in the affected areas, such as by the provision of information and advice, and by monitoring.
  18. The conditions prevailing after the completion of remedial actions, if the regulatory body or other relevant authority has imposed no restrictions or controls, shall be considered to constitute the background conditions for any new facilities and activities or for habitation on the land.
  Requirement 50: Public exposure due to radon indoors
  The government shall provide information on levels of radon indoors and the associated health risks and, if appropriate, shall establish and implement an action plan for controlling public exposure due to radon indoors.
  19. As part of its responsibilities, as required in para. 5.3, the government shall ensure that:
      1. Information is gathered on activity concentrations of radon in dwellings and other buildings with high occupancy factors for members of the public⁵³ through appropriate means, such as representative radon surveys;
      2. Relevant information on exposure due to radon and the associated health risks, including the increased risks relating to smoking, is provided to the public and other interested parties.
  20. Where activity concentrations of radon that are of concern for public health are identified on the basis of the information gathered as required in para. 5.19(a), the government shall ensure that an action plan is established comprising coordinated actions to reduce activity concentrations of radon in existing buildings and in future buildings, which includes⁵⁴:
      1. Establishing an appropriate reference level for ²²²Rn for dwellings and other buildings with high occupancy factors for members of the public, with account taken of the prevailing social and economic circumstances, that in general will not exceed an annual average activity concentration due to ²²²Rn of 300 Bq/m^{3 55};
      2. Reducing activity concentrations of ²²²Rn and consequent exposures to levels at which protection is optimized;
      3. Giving priority to actions to reduce activity concentrations of ²²²Rn in those situations for which such action is likely to be most effective⁵⁶;
      4. Including in building codes appropriate preventive measures and corrective actions to prevent the ingress of ²²²Rn and to facilitate further actions wherever necessary.
  21. The government shall assign responsibility for:
      1. Establishing and implementing the action plan for controlling public exposure due to ²²²Rn indoors;
      2. Determining the circumstances under which actions are to be mandatory or are to be voluntary, with account taken of legal requirements and of the prevailing social and economic circumstances.
  Requirement 51: Exposure due to radionuclides in commodities
  The regulatory body or other relevant authority shall establish reference levels for exposure due to radionuclides in commodities.
  22. The regulatory body or other relevant authority shall establish specific reference levels for exposure due to radionuclides in commodities such as construction materials, food and feed, and in drinking water, each of which shall typically be expressed as, or be based on, an annual effective dose to the representative person that generally does not exceed a value of about 1 mSv.
  23. The regulatory body or other relevant authority shall consider the guideline levels for radionuclides in food traded internationally that could contain radioactive substances as a result of a nuclear or radiological emergency, which have been published by the Joint Food and Agriculture Organization of the United Nations/World Health Organization Codex Alimentarius Commission [23]. The regulatory body or other relevant authority shall consider the guideline levels for radionuclides contained in drinking water that have been published by the World Health Organization [24].
• OCCUPATIONAL EXPOSURE
  Scope
  
  24. The requirements in respect of occupational exposure in existing exposure situations (paras 5.25–5.33) apply to any occupational exposure arising from the situations specified in para. 5.1.
  Requirement 52: Exposure in workplaces
  The regulatory body shall establish and enforce requirements for the protection of workers in existing exposure situations.
  25. The requirements in respect of public exposure stated in paras 5.7–5.9 shall be applied for protection and safety for workers in existing exposure situations, other than in those specific situations identified in paras 5.26–5.33.
  Remediation of areas with residual radioactive material
  26. Employers shall ensure that the exposure of workers undertaking remedial actions is controlled in accordance with the relevant requirements on occupational exposure in planned exposure situations as established in Section 3.
  Exposure due to radon in workplaces
  27. The regulatory body or other relevant authority shall establish a strategy for protection against exposure due to ²²²Rn in workplaces, including the establishment of an appropriate reference level for ²²²Rn. The reference level for ²²²Rn shall be set at a value that does not exceed an annual average activity concentration of ²²²Rn of 1000 Bq/m³, with account taken of the prevailing social and economic circumstances.⁵⁷
  28. Employers shall ensure that activity concentrations of ²²²Rn in workplaces are as low as reasonably achievable below the reference level established in accordance with para. 5.27, and shall ensure that protection is optimized.
  29. If, despite all reasonable efforts by the employer to reduce activity concentrations of radon, the activity concentration of ²²²Rn in workplaces remains above the reference level established in accordance with para. 5.27, the relevant requirements for occupational exposure in planned exposure situations as stated in Section 3 shall apply.
  Exposure of aircrew and space crew due to cosmic radiation
  30. The regulatory body or other relevant authority shall determine whether assessment of the exposure of aircrew due to cosmic radiation is warranted.
  31. Where such assessment is deemed to be warranted, the regulatory body or other relevant authority shall establish a framework which shall include a reference level of dose and a methodology for the assessment and recording of doses received by aircrew from occupational exposure to cosmic radiation.
  32. In accordance with para. 5.31:
      1. Where the doses of aircrew are likely to exceed the reference level, employers of aircrew:
         1. Shall assess and keep records of doses;
         2. Shall make records of doses available to aircrew.
      2. Employers:
         1. Shall inform female aircrew of the risk to the embryo or fetus due to exposure to cosmic radiation and of the need for early notification of pregnancy;
         2. Shall apply the requirements of para. 3.114 in respect of notification of pregnancy.
  33. The regulatory body or other relevant authority shall establish, where appropriate, a framework for radiation protection that applies to individuals in space based activities that is appropriate for the exceptional conditions of space. While the requirements of these Standards in respect of dose limits do not apply to individuals in space based activities, all reasonable efforts shall be made to optimize protection for individuals in space based activities by restricting the doses received by such individuals while not unduly limiting the extent of such activities.