Radioactive waste management

The waste management aspects are reviewed throughout the life cycle of the plants, right from the siting stage, to construction, commissioning, operation and decommissioning stage of a NPP. Operating nuclear power plants generate solid, liquid and gaseous wastes. As a waste management philosophy, no waste in any physical form is released to the environment unless the same is cleared, exempted or excluded from regulations. Utmost priority is given to waste minimization, and volume reduction in the choice of processes and technologies adopted in radioactive waste management plants. The general philosophy for radioactive waste management being followed is as below:

• Delay and decay of short-lived radionuclides;
• Concentrate and contain activity as practicable; and
• Dilute and disperse low-level radioactive waste within the authorized limits.

The low level solid, liquid and gaseous wastes generated from nuclear power plants are disposed off as per approved method after ensuring compliance with the regulatory requirements. The current regulations specify that the radiation dose to the members of public living near the operating NPPs due to the discharge from the plants shall not exceed annual limit of 1 mSv (i.e 1000 micro-Sievert). This is in line with the limits set by International Commission on Radiological Protection (ICRP). Further based on the above limit, AERB issues ‘authorization’ which specifies the limits in terms of quantity and activity content of the waste that can be disposed. These authorisations are valid for three years and renewed after review of the  performance of NPPs. AERB has further specified limits on liquid and gaseous radioactive discharges, through gaseous or liquid routes, in the Technical Specifications for operation of NPPs. These technical specification limits are set far below the dose apportionment to the public for the specific radionuclide.

The processing technologies adopted for management of nuclear waste are summarized below:

• Solid waste: Solid waste generated from nuclear power plants after suitable conditioning are disposed off in Near Surface Disposal Facilities (NSDF) located within the exclusion zone boundary of nuclear power plants. Near Surface Disposal Facilities are designed and constructed to contain the radionuclides within the disposal system until the  radionuclides decay  to negligible activity level.
• Liquid waste: Low level liquid waste generated from nuclear power plants are discharged to the environment after suitable treatment and ensuring compliance with the regulatory limit. The treatment system essentially comprises chemical treatment, evaporation, ion exchange, filtration etc.
• Gaseous waste: Gaseous waste is treated at the source of generation. The gaseous wastes are discharged to the environment through 100 m high stack after filtration and dilution with continuous monitoring of radionuclides and compliance with the regulatory limits.

India has adopted closed fuel cycle option, which involves reprocessing and recycling of the spent fuel. During reprocessing, only about two to three percent of the spent fuel becomes waste and the rest is recycled. At the end the high level waste will be emplaced in geological disposal facilities.

Nuclear power plants are supposed to submit “return of waste disposed” to AERB. AERB  reviews whether the wastes disposed by NPPs are within the limits specified in technical specification during regulatory inspections. Also independent environmental survey is done by Environment Survey Labs instituted by BARC to assess the actual impact of the above releases to the environment.

AERB issues authorization for disposal of radioactive wastes under Atomic Energy (Safe Disposal of Radioactive Wastes) Rules, 1987. The evaluation of waste management aspects of the facilities under AERB regulation is carried out as per AERB Safety Code on Management of Radioactive Waste (AERB/NRF/SC/RW, 2007) (122 KB) , AERB Safety Guide on Classification of Radioactive Waste (AERB/NRF/SG/RW-1, 2011)and Management of Radioactive Waste from Mining and Milling of Uranium and Thorium (AERB/NF/SG/RW-5, 2007). (121 KB) 

Management of spent radioactive sources and radioactive waste arising from the use of radionuclides in medicine, industry and research, including decommissioning of such facilities

Radionuclides, in the form of sealed and unsealed sources, are extensively used in medicine, industry, agriculture, research and various other applications. Such applications could result in generation of significant quantities of solid and liquid wastes and occasionally gaseous wastes. Much of the solid waste consists of contaminated items, such as paper, plastics, glassware, equipment, animal carcasses, excreta and other biological waste. Some of the solid wastes may have considerable activity and small volumes as in the case of spent sealed sources.

Liquid radioactive wastes comprise of aqueous and organic streams, such as patients’ urine (primarily in thyroid cancer therapy) and effluents from decontamination processes. In many applications of radionuclides, the radioactive waste generated may comprise of short-lived radionuclides, which may be managed by providing storage for decay.

Gaseous waste may be generated from the production and radio labelling of chemical compounds and organisms, also during the production of radionuclides and from the treatment of solid and liquid waste.

However, in applications, which involve long-lived radionuclides, an appropriate waste management programme should be in place prior to the start of the work with radionuclides.

Principles and philosophy of radioactive waste management

Applications of these principles will ensure adequate safety in the management of radioactive waste.

These principles are:

Principle 1: Protection of Human Health and Environment

Radioactive waste shall be managed in such a way as to provide an acceptable level of protection for human health and the environment.

Principle 2: Concern for Future Generations

Radioactive waste shall be managed in such a way that it will not impose undue burden on future generations and its predicted impact on the health of future generations will not be greater than relevant levels of impact that are acceptable today.

Principle 3: Establishing Legal Framework

Radioactive waste shall be managed within an appropriate legal framework including clear allocation of responsibilities and provision for independent regulatory functions.

Principle 4: Waste Minimisation, Management Interdependency and Safety of Facilities

Generation of radioactive waste shall be kept to the minimum practicable. Interdependency among all steps in radioactive waste generation and management shall be taken into account. The safety of facilities for radioactive waste management shall be assured during their lifetime.

Associated Document:

Management of Spent Radioactive Sources and Radioactive Waste Arising from the Use of Radionuclides in Medicine, Industry And Research, including Decommissioning of Such Facilities (100 KB)