[en] In a radiation accident involving a remote controlled radiography camera, the source capsule got ruptured and the source pellets of total activity 24 Ci iridium-192 got dispersed to different parts of the equipment. One of the pellets found its way to a bituminous road (private). The source pellets being tiny, the management of the situation was a tedious affair and involved a certain amount of risk to the persons who participated in the salvage operations. This paper gives an account of the problems involved and their management. (author)

[en] Radioisotopes find many applications in the industrial field. As the use of radioisotopes is associated with potential health hazard, to workers and public, it is necessary to develop suitable manpower capable of handling radiation sources in a safe manner. This is brought about through different training programmes arranged by the Radiological Physics Division, Radiation Protection Services Division and Isotope Division of Bhabha Atomic Research Centre. The contents of these programmes are covered in this paper. (author). 2 tabs

No abstract available

[en] Activation analysis is a very useful method in the analysis of mineral ores. Analysis with short half-life isotopes produced by neutron activation is well suited for 'in-situ' or 'on-stream' analysis of mineral ores, on account of short irradiation times and relatively less radiation hazards. Some studies were conducted for the estimation of aluminium content of simulated bauxite ore using californium-252 neutron source (yield-1.8x10⁷n/sec) and also americium-241/Be source (yield: 2.2x10⁶n/sec). The aluminium content was determined by using the reaction ²⁷Al(n,γ)²⁸Al formed by thermal neutrons. The ore sample was irradiated to mixed neutrons and cadmium ratio method was adopted to eliminate the interference from fast neutrons. The californium sources were placed in a circular array around the sample in a cylindrical block of paraffin wax, used as a thermalising medium. A scintillation detector, coupled to a portable counting set-up, was used to monitor the activated sample. This helps: (a) to avoid the interference from gamma radiations other than that from aluminium-28 and (b) to improve the lower limit of detection. By this method, a sample could be analysed in about 12 minutes. The minimum concentration of aluminium which could be determined by this method was 1%. The precision in the measurement was better than +- 5% at 67% confidence level. Americium-241/Be was found to be less sensitive than californium-252. (auth.)

[en] The results of studies carried out on the use of β back-scattering technique for the evaluation of personnel monitoring film exposure, are reported. The response curves of fast and slow emulsions of two types of films for γ exposures and using ³⁵S and ¹⁴⁷Pm sources are shown. The results indicate that β backscattering technique can be used for evaluation of γ exposures using processed films. This method is simple and has several advantages such as easy availability of source and equipment ease of operation, independent evaluation using both sides of the film (Kodak Type 2), better sensitivity and suitability for entire range of exposures in personnel monitoring. Changes in optical density of processed film occur on storing the films for long periods thus giving rise to errors in evaluation whereas the β backscattering technique is free from this drawback since the method is based on the measurement of silver concentration. Because of the type, energy and activity of the source used, the method does not pose any radiation hazard during use. (U.K.)

[en] Studies were carried out on the use of low energy photon transmission technique for the evaluation of gamma exposures recorded by film dosimeters. A GM counter with a compact counting equipment was used for recording Ti X-rays (³H/Ti source) transmitted through the processed film. The results of the studies carried out on Kodak type 2 and Agfa-Gevaert PM films are reported. By this technique, exposures from 25 mR to as high as 900 R could be estimated with reasonable accuracy. (Auth.)

[en] The various aspects of radiation protection in the application of radioisotope sources in the field of non-destructive testing are described. Methods of evaluation and control of radiation hazards associated with isotope radiography are discussed. Working procedures to minimise radiation exposures to personnel are suggested. The importance of education and training in minimising the hazard is indicated. (author)

No abstract available

[en] Use of gamma radiation sources for non-destructive testing of welds, castings and vital components in several industries in India has recorded a steep rise in the last three decades. There are over 1000 industrial gamma radiography exposure devices (IGRED) in over 400 institutions in the country. Most of these employ Co-60 and Ir-192 gamma sources. In spite of regulatory control and procedures there have been accidents with the IGREDs resulting in significant radiation exposures and in some cases, injuries to members of public and radiography personnel. This paper analyses the accidents which occurred in India during the ten year period of 1987-1997, management of such accidents, steps taken to avoid recurrence of these accidents based on the lessons learnt. (author)

[en] A radiation incident took place inside an open-top radiography enclosure involving an Amertest-676 exposure device containing a cobalt-60 source of activity 2.15 TBq. The exposure device was being checked after receipt of a fresh source. The source assembly having been projected out could not be brought back into the exposure device. After thorough planning, the situation was brought under control by driving the disengaged source assembly into the exposure device. During the incident, the maximum individual whole body dose was 3.1 mSv. (author)