1The volume of NORM residues can range from less than one cubic metre up to millions of cubic metres.

2INTERNATIONAL ATOMIC ENERGY AGENCY, Management of Radioactive Waste from the Mining and Milling of Ores, IAEA Safety Standards Series No. WS-G-1.2, IAEA, Vienna (2002).

3The criteria in para. 3.4(a) of GSR Part 3 [4] represent (in order of magnitude terms) the upper bounds of the activity concentrations in normal soil.

4The list is not exhaustive. NORM residues that might be of regulatory concern can also arise from other sectors, such as the potash industry, geothermal energy use, use of deep water with a high mineral content, limestone processing and shale gas production.

5The terms ‘radon’ and ‘thoron’ include not only the parent radionuclides — ²²²Rn and ²²⁰Rn, respectively — but also their short lived progeny.

6For facilities and sites where NORM industries have been operating for a long time, the monitoring programme for establishing natural radiation levels may need to focus on representative locations away from the immediate vicinity of the site.

7In special circumstances, a higher value of effective dose could apply in a single year, providing that the average effective dose over five consecutive years does not exceed 1 mSv in a year.

8‘Scenario’ is defined as a postulated or assumed set of conditions or events [1].

9A form of authorization for facilities and activities of low or moderate risk whereby the person or organization responsible for the facility or activity has, as appropriate, prepared and submitted a safety assessment of the facilities and equipment to the regulatory body.

10This does not imply that control of radon is excluded. The exposure resulting from radon needs to be assessed to support regulatory decision making and supporting measures for protection and mitigation.

11‘Operational limits and conditions’ are a set of rules setting forth parameter limits, the functional capability and the performance levels of equipment and personnel approved by the regulatory body for safe operation of an authorized facility [1].

12A ‘near miss’ is defined as a potential significant event that could have occurred as a consequence of a sequence of actual occurrences but did not occur owing to the conditions prevailing at the time [1].

13‘Processing’ is considered to be any operation that changes the characteristics of residues, including pretreatment, treatment and conditioning.