Natural Radiation Sources

HERCA activities related to natural radiation sources, i.e. radon, naturally occurring radioactive materials (NORM) and building materials, are under the responsibility of WG Natural Radiation Sources (WG NAT).

Previously to the official creation of the WG NAT, HERCA organised in 2014-2016, three international workshops of high relevance for understanding and transposition of the EU BSS requirements on Radon, naturally occurring radioactive material (NORM) and building materials. These workshops raised different issues including the need to compare national approaches and to exchange on technical issues. Therefore, HERCA Board approved the creation of a working group dealing with natural radiation sources late 2017.

The follow-up HERCA workshop on National Radon Action Plan (NRAP), in organisation of WG NAT, is currently scheduled for 14-16 June 2022, Bucharest, Romania. In order to provide an introduction to this workshop, an online pre-workshop event on NRAP was held on 23 March 2021.

Workshop on NORM and Building Materials

HERCA, with the support of CSN, ASN, and NRPA, organised a Workshop on NORM and Building Materials. This workshop took place on 24-26 May 2016 in Bergen (Norway). HERCA members’ organizations exchanged on the transposition of the specific requirements of the Directive 2013/59/Euratom (Euratom-BSS) dealing with NORM and Building Materials. HERCA issued a “Common understanding of the BSS requirements and recommendations” in June 2017.

2nd Workshop on Radon in Workplaces

HERCA organised a second workshop on Radon in workplaces in the framework of the Euratom BSS directive transpoition works (12-14 October 2015, Geneva, Switzerland).

Other link : Workshop on radon national plans (30 Sept. – 2 Oct. 2014)


  • To exchange and compare the different national approaches developed in the framework of the implementation of the BSS directive and associated European directives and regulations with regard to natural ionising radiation.
  • To develop approaches on specific issues focused on radon, NORM and building materials respecting national conditions and legislations.
  • To identify and develop an exchange of knowledge and experiences with relevant stakeholders, including the European Commission.

Action Plan

  1. To exchange information about national regulations with regards to the implementation of specific BSS directive requirements on radon, NORM and building materials.
  2. To organise the postponed (due to Covid-19 pandemic in 2020 and 2021) follow-up workshop on National Radon Action Plans (NRAP), including an online pre-workshop event on that topic.
  3. To finalize the work and publish a HERCA Guide on Application of the concepts of Exemption and Clearance to the regulation of the naturally occurring radioactive materials (NORM) across HERCA countries.
  4. To organise the follow-up workshop on the topic of NORM issues in metal mining and processing.
  5. To continue to explore more specific issues within the topic of:
    1. Radon
      • The application of a graded approach and of the optimization principle for the regulation of radon at workplaces
      • Effectiveness of radon control actions, including indicators regarding radon in workplaces and dwellings
      • Integration of radon with general requirements on indoor air quality
    2. NORM
      • Graded approach to regulation of NORM related industries – application of the optimization principle
      • National approaches to NORM waste/residue management, including definition/categorization of waste material, disposal options and control of liquid and gaseous NORM discharges
      • Commodities containing NORM
      • Use of operational quantities to facilitate the measurement of surface contamination
      • National inspection frameworks with regard to NORM activities
      • Protection of outside workers with regards to NORM activities
    3. Building materials
      • Develop an overview of the implementation of BBS Article 75-2 regarding the indicative list of materials of concern set out in Annex XIII.
  6. To identify and develop exchanges of knowledge and experiences with relevant stakeholders: EC, CEN, ICRP, IAEA, WHO, UNSCEAR, IRPA, ERA (European Radon Association), ENA (European NORM Association), OECD and others.


Wolfgang RINGER
Head of Department for Radon and Radioecology [AGES]
Senior Officer - Environmental Planning and Protection Unit [APA]
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