Nuclear science has many dimensions-some result from large energy available in the nucleus of an atom and others from the radiation emanating from it. Developments in science have enabled us to master the ability to harness this energy and put it to beneficial applications for our society. The Department of Atomic Energy (DAE) has set up 14 reactors in the country which convert energy from the atom into electricity and are powering many homes, industries and agricultural operations. The linkage between electricity consumption and the GDP is well established. The nuclear power reactors set up by DAE have so far produced about 180 billion units of electricity.

Radiation emanates from the atom. It has applications in many areas including health care, agriculture, food preservation, industry and research. Parallel to the nuclear power programme, radiaion technology application has also made considerable progress in our country. Within DAE, there is a unit called Board of Radiation and Isotope Technology (BRIT) which channelises applications to society. Radiation can be produced by radio isotopes or by accelerators. Research reactors at Trombay regularly produce a variety of radioisotopes and meet a major part of their demand in the country. In addition to research reactors, power reactors have been equipped to produce Cobalt-60. While indigenous capability to design and construct research reactors is well established, good progress has also been made in developing accelerators. At the Centre for Advanced Technology (CAT), Indore, along with accelerators, work is also going on indigenous lasers for a variety of applications. This has been a very successful programme. Based on radiation technology applications, we have made significant contributions in health care, food and agriculture and industry in recent years

The Radiation Medicine Centre (RMC) of the Bhabha Atomic Research Centre (BARC) in Mumbai has become the nucleus for the growth of nuclear medicine in the country. Similarly, the Tata Memorial Centre (TMC), a fully aided autonomous institution of DAE, provides comprehensive treatment for cancer and allied diseases and is one of the best in the country. It carries out a large number of patient investigations every year. To cater to the requirements of the eastern region, a regional radiation medicine centre is located in Kolkata as a part of the Variable Energy Cyclotron Centre (VECC).

A very large variety of radio isotopes are used both for diagnosis and therapy. They are used either as radio pharmaceuticals or radiation sources. These are supplied to nearly 120 Nuclear Medicine Centres in the country by BRIT. Tc-99m is the main workhorse of nuclear medicine practice. 1-31 as sodium iodide is used for diagnosis and treatment of thyroid disorders. Radioimmunoassay (RIA) is an important medical application of radioisotopes. This is a simple and affordable technique for diagnosis. There are nearly 650 laboratories in India offering RIA services. BRIT regularly provides RIA kits to these centres.

Intense Co-60 sources ranging from 9000 to 12000 curies encapsulated and supplied by BRIT are being used in most of the 170 teletherapy units set up in 62 cities in India for cancer treatment. Brachytherapy sources using lr-192 as well as Cs-137 are supplied by BRIT for cancer treatment. BRIT also supplies P-32 injection for pain palliation in severe bone cancer cases.

The RMC of BARC, Mumbai has been conducting a one-year diploma course in Radiation Medicine (DRM) to provide trained manpower to other RMCs. A one-month course on RIA is also conducted by the radiopharmaceuticals division of BARC.

The CAT at Indore has developed lasers for medical applications. The surgical Co2 laser system developed by them is useful for a range of surgical modalities such as ENT, gyanecology, general surgery, dermatology and plastic surgery. These systems have been supplied to various hospitals within the country such as AIIMS, New Delhi; Choithram Hospital & Research Centre, Indore; Shri Vivekananda Medical College, Kolkata; Shri Chitra Tirunal Institute, Thiruvananthapuram and Bio-Medical Engineering Group, IIT, New Delhi.

A patient suffering from tuberculosis develops cavities in lungs. Exposure of these cavities to nitrogen laser radiation helps in drug penetration. It has also been observed that exposure of burn wounds to nitrogen laser radiation helps in faster healing. Three nitrogen laser units with fibre optic beam delivery systems have been given to Choithram Hospital and Research Centre, Indore; Maharaja Yashwant Hospital, Indore and Sen Research Centre, Patna for treatment of tuberculosis.

Another important application of radioisotopes towards health care is by way of radiation sterilisation services offered on commercial basis to Indian medical industry. A number of products such as disposable syringes, surgical sutures and dressing are sterilised by irradiation. The Irradiation Sterilisation of Medical Products (ISOMED) Plant at Trombay was the first unit to be pressed into this service by DAE. The second radiation sterilisation plant has been established in Bangalore and the third one in New Delhi. During 2000-2001, about 13,000 cubic metres of medical products were processed with over 90 per cent plant availability factor at ISOMED. Its services obtained ISO 9002 certification thus enabling better acceptance of ISOMED service internationally.

The national agriculture policy document lays a major thrust on higher productivity based on technically sound, economically viable, environmentally non-degrading and socially acceptable use of natural resources-land, water and genetic endowment.

Through its research and development activities in nuclear science and technology, DAE has been making active contribution towards enhancing agricultural production and food preservation. BARC has a broad-based research programme in nuclear agriculture involving genetic improvement of crops by mutation breeding and biotechnological approaches, isotope-aided studies on soils, fertilisers uptake and pesticide residue analysis and integrated pest management including the use of sterile insect technique. Using induced mutations and cross breeding, 22 crop varieties have so far been developed and released for commercial cultivation. Among them are eight groundnut, 10 pulses and two mustard varieties and one variety each of jute and rice. These improved varieties have high yields and they are resistant to diseases. They are contributing directly to the increase of GDP in the country.

One of the major achievements in radiation-induced mutation is the development of photoperiod insensitive green manure crop-sesbania rostrata. This West African legume harbours nitrogen fixing nodules both in the root and stem. The mutant TSR-1 (Trombay sesbania rostrata) is photoperiod insensitive and can be grown throughout the year with higher biomass. Studies have revealed that 120-160 kg of nitrogen from a biomass of 10 tonnes per hectare can be added to the soil by ploughing in the plants grown for 55-60 days. The decomposition takes around 15 days after which the soil is ready for sowing. Growth parameters and yield of rice crop following TSR-1 as a green manure were similar to that grown with 60-kg nitrogen per hectare of chemical fertiliser.

Based on the research done in BARC and other research centers in the world, advantages of food preservation by irradiation have been clearly demonstrated and the Centre has cleared certain items for radiation treatment. Setting up of such plants is expected to reduce the percentage of food that is lost by various causes and provide a method for improving food hygiene and facilitate export.

BARC has also developed a tissue culture-based protocol for rapid multiplication of 12 commercial varieties of banana. This technology has been transferred to Maharasthra State Seeds Corporation, Akola. They have established a commercial tissue culture laboratory and are distributing plants to farmers. This technology has also been transferred to the Pondichery government. Similarly, a large-scale multiplication of pineapple by micro-propagation has been standardised. From a single bud of a crown, over 95 plants are produced within 6 months compared to only one in the conventional procedure practised by the farmers. The Government of Tripura has shown interest in this technique. Accasia victoriae is a plant suitable for desert area and can withstand salinity. Good progress has been made in developing hardened plants for this variety using micropropagation. Field trials are now planned in collaboration with the Rajasthan Agricultural University. Success in this area will help in greening the desert.

Applications of radiation technology in health care, industry, food and agriculture are of direct benefit to society. DAE is working on all aspects such as production and supply of sources of radiation, use of radiation for known applications and research and development aimed at acquiring new applications, design and manufacture of equipment and plants to facilitate the use of radiation technologies and their deployment in the country. DAE is now trying to reach user agencies for wider deployment of such technologies so as to provide larger benefit to society and to make higher contribution to the health and prosperity of people.