Implementation of ICRP-60 recommendations on dose limits to radiation workers in India

The handling of radioactive material and radiation generating plants in India is regulated by the Atomic Energy Act, 1962 and rules issued under the Act. The Atomic Energy Regulatory Board enforces the rules. Currently, there are about 40,000 radiation workers in the country. Nearly half of them are employed in nuclear installations. During 1989, the Board considered the impact of restricting the maximum individual exposure to different values of dose limits. Through this analysis, the Board alerted all radiation users including persons responsible for radiation safety in nuclear facilities. When ICRP published ICRP-60, the Board issued directives to all radiation installations reducing the dose limit to occupational workers in a phased manner (40 mSv for 1991, 35 mSv for 1992 and 30 mSv for 1993). To meet the recommendations of ICRP-60, AERB issued a directive for the five year block 1994-1998, restricting the cumulative effective dose constraint to one hundred milliSievert (100 mSv) for individual radiation workers. Also, the annual effective dose to individual workers in any calendar year during the five-year block was restricted to thirty milliSievert (30 mSv). The stipulations of AERB are thus more conservative than those of ICRP. There was near total compliance with the dose limits by radiation installations in the country. For instance, in 1989, the number of radiation workers in nuclear power plants, who exceeded the dose level of 20 mSv/year was 9% of the total. This declined gradually to 2.2% in 1993 and 0.3% in 1997. During 1998, only 9 out of 10,145 exceeded 20 mSv/year. This has been achieved by the concerted efforts of the management, health physics staff and radiation workers. The health physicists regulated the radiation doses to workers by issuing work permits when the workers are assigned any job in high radiation areas. Appropriate training programmes are also in place. The broad guidelines to regulate radiation exposures in nuclear facilities are contained in the AERB Safety Manual for Radiation Protection for Nuclear Facilities (Revision 3) issued in November 1996. In the medical, industrial and research applications of radiation, advice on matters related to radiation protection is given by radiological safety officers recognized by the Atomic Energy Regulatory Board. The numbers of workers exposed to doses above 20 mSv/year in medical institutions were 0.27% in 1989 gradually lowering to 0.18% in 1998. The corresponding number of workers in industrial applications of radiation is 1.92% in 1989 down to 0.45% in 1998. As a follow up measure, AERB set up an apex committee presided over by a Member of the Board and consisting of a health physicist, radiation oncologist, radiologist, industrial hygiene specialist, medical physicist, an expert in personnel management and industrial relations to review all radiation exposures exceeding 20 mSv per year and recommend appropriate measures. The Committee was empowered to call for records and ask the representatives of the management to be present during the review. This procedure helped to attract the attention of the highest levels of management. The steps taken to enforce compliance will be explained. (author)