Year : 2011 | Volume
: 34 | Issue : 3 | Page : 152-
Norm and tenorm waste management
Ex. BARC, India
Editor, Radiation Protection and Environment, C/o Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400 085
|How to cite this article:|
Pushparaja. Norm and tenorm waste management.Radiat Prot Environ 2011;34:152-152
|How to cite this URL:|
Pushparaja. Norm and tenorm waste management. Radiat Prot Environ [serial online] 2011 [cited 2021 Jan 15 ];34:152-152
Available from: https://www.rpe.org.in/text.asp?2011/34/3/152/101680
The acronym stands for Naturally Occurring Radioactive Materials. Almost everything in nature has small mounts of naturally occurring radionuclides. The examples are naturally occurring Uranium, Thorium and their decay products such as Radium and noble gases-Radon isotopes; Potassium-40 and Carbon-14 isotopes. These radionuclides are present in the earth crest, in coal, in gas and in oil, in parts per million (ppm) levels. The levels vary widely. When the ores/minerals containing the radionuclides are processed for recovery of the useful materials, the process waste is generated and this process waste will have enhanced levels of the radioactivity as radionuclides get concentrated in the process waste, solid or liquid. Such materials are called Technologically-Enhanced NORM waste material (TENORM). The chemical, physical and radiological properties of the radioactive species are likely to be altered which may result in increased environmental mobility in soil and water thus altering the radiological risk potential. The storage/ disposal of the waste is an important issue with respect to radiological protection considerations-health risk from exposure to low levels of radiation and radioactivity.
In energy sector where natural resources such as coal, oil, natural gas are used to generate electricity, there is potential to generate TENORM/NORM waste during exploration. When the coal is burnt in the power plants, the NORM present in the coal gets concentrated in the waste-fly ash. The fly ash, if used for preparation of bricks poses enhanced radiological hazard for the dwellers who reside in such dwellings built out of the bricks. TENORM is found in waste streams of industries which produce uranium, thorium, phosphoric acid, copper, tin, zirconium and oil and gas exploration. Thus, the disposal of TENORM waste is a global issue that involves technology, business, environment, public perception and politics.
In general, except in nuclear fuel cycle operations, the NORM/TENORM wastes are not well regulated by the governments, probably due to ignorance of the hazard, the large quantity of the waste generated and the exposures to the low levels of radiation are uncontrollable.
In recent years, the awareness of exposures to NORM/TENORM is increasing and environmental safety issues are seriously taken up by the governments since any increased exposure to radiation can be harmful as per the Linear Non-Threshold (LNT) theory. All exposures to radiation should be optimized, and kept As Low As Reasonably Achievable (ALARA), social and economic factors being taken into account.
Monitoring of the work areas, equipments, waste storage/disposal facilities should be carried out and compared with the values of exempted levels provided by the IAEA-BSS for uncontrolled disposal of the NORM waste. If the levels are in excess of the exempt levels draw the attention of the national regulators to the expected radiation exposure concerns. It is important that the regulators carry out the radiation survey to confirm the NORM issue and make a safety assessment of the personnel exposure situation and suggest possible remedial measures, safe work procedures, use of personal protective equipment, personnel dosimeters, etc. for the safety of the workers, the members of the public and the environment. The policy should clearly address the requirements for good NORM/TENORM management including - NORM awareness, reduction in the amount of NORM waste generated, disposal options, use of trained manpower, regular survey, decontamination of the NORM contaminated areas/equipment, maintenance of the personnel dose records, etc.
Building, maintenance and surveillance of disposal sites can be resource-intensive in terms of manpower and money. Whether the regulatory intervention and control are worth the efforts, economically and operationally? Do we have to have different criteria for intervention similar to radon for such "uncontrollable" exposure situations? Whether IAEA-BSS is applicable for the TENORM waste disposal? These are the questions to be answered in near future.