RADIOLOGICAL SAFETY PRACTICES EXPERIENCED IN HANDLING OF RADIOACTIVE SOURCE DURING RADIOGRAPHIC TESTING, CALIBRATION AND RESPONSE CHECK OF INSTRUMENTS DURING THE PROJECT STAGE OF 500 MWE PROTOTYPE FAST BREEDER REACTOR (PFBR)

The presence and effect of ionizing radiation is detected and measured only with the help of radiological instruments as radiation is non sensory. The radioactive half-life of the radionuclide bears significance in assorting the radiation protection measures. The efficiency and resolution of the radiation detection instrument is influential in detection of the contamination present on the surface of the equipment and other materials lying on the floors and walls of the buildings emitting alpha (α), beta (β), gamma (γ) radiations, neutron and gamma leaking out of reactor systems. Thus they play a vital role in choosing the appropriate instruments to put into use for detection. The efficiency of the instrument stands prompt to detect the presence of contamination and the resolution helps identify the radionuclide which produces that contamination. The radiological instruments which would consist of ion chamber, proportional counter, Geiger Muller tube, plastic scintillator etc., need to be calibrated with a known radioactive source of appropriate strength of activity depending upon the range of the instrument finalized