Radiation exists at every corner of the earth. The intensity of the radiation verifies from one place to another. Due to low level of radiation, we are unable to feel its impact. It is produced naturally and artificially also. Medical equipment’s like x-ray machines, microwaves, radio frequency, ultraviolet rays, gamma, and others are source of radiation.

Depends upon the type of radiation and the ability to penetrate other materials or medium. Alpha and beta radioactive particles can’t travel too far at all, and they are easily blocked due to less penetrating ability. But gamma rays, x-rays, and neutrons travel a notable distance and are difficult to block naturally (particularly for large radioactive sources).

Alpha (α) radiation consists of a fast-moving helium-4 (4 he) nucleus and is stopped by a sheet of paper.

Beta (β) radiation, consisting of electrons, is halted by an aluminium plate.

Gamma (γ)radiation, consisting of energetic photons, is eventually absorbed as it penetrates a dense material.

Neutron (n) radiation consists of free neutrons that are blocked by light elements, like hydrogen, which slow and/or capture them. Not shown : galactix cosmic rays that consist of energetic charged nuclei such as protons, helium nuclei, and high charged unclei called HZE ions.

Our Country has a long-term plan of wide applications of nuclear radiations and radioactive sources for peaceful applications for mankind. Like in; medicine, industry, agriculture and research. Already having several places in the country where such sources are being used. These places are mostly outside of the Department of Atomic Energy (DAE) installations. DAE supplies such sources. The most important application of nuclear energy in DAE is in electricity generation through nuclear power plants. Around 22 such nuclear reactors are operating now. In view of the above mentioned wide spread applications, Indian parliament through an Act, called Atomic Energy Act, 1962 created an autonomous body called Atomic Energy Regulatory Board (AERB) with authority and powers. This Board issues licenses, codes, guides, manuals, etc., to regulate such installations to ensure safe use of such sources and crews engaged in such installations and environment, receives radiation exposures within the maximum limit prescribed by them. Periodic reports are submitted to AERB to demonstrate compliance of its directives. Health, Safety and Environment (HSE) Group of Bhabha Atomic Research Centre (BARC), Mumbai and various regional offices carry out necessary surveillance and monitoring of all installations of the DAE on a routine basis and periodic inspections of other installations using radiation sources. Some of the nuclear fuel cycle plants like nuclear power plants and fuel reprocessing involve large radioactive source inventories and have potential of accidental release of radioactivity into the environment. The data is provided to AERB and is available to members of the public. In addition, a multi-tier system of AERB permissions is in place to ensure that all aspects of safety have been considered before permission to operate is granted. The stages where permission of AERB is essential are site selection, design data, and several stages during construction and operation. The details required by AERB include provision for treatment and storage of radioactive waste, de-commissioning procedures and provision of costs. In addition to AERB, nuclear power plants must comply with the requirements of Ministry of Environment and Forests and get their clearance. This is given based on Environmental Impact Assessment Report which should satisfy the authorities that no ecological damage will be caused, and the facility will not have adverse effect on the environment. In addition, the State Pollution Control Board where the facility is to be located must permit the site of the plant for its proposed discharges into the environment. It is largely due to the above comprehensive regulatory controls that none of the plants in India had any accident during the last 34 decades of operation. The type of measurements carried out by the ESL’s and results from a few typical ESL’s will be presented.