No abstract available

[en] This paper discusses the safety features related to a workshop when tritium activated luminous paint is handled by workmen. Salient features of the workshop and the methods employed for monitoring the radiation levels are briefly outlined and results are discussed. The importance of proper ventilation of the workplace and precautions to be taken in the storage of painted articles are highlighted. (author). 1 table, 3 figs

[en] Radioactive aerosols are generated during operations (transfer, cutting, storage and shipment of fuel) in spent fuel bays. A study has been carried out on the airborne concentration, size distribution and solubility of the aerosol, to evaluate the inhalation exposure of the workers. Personal air samplers were used for the measurement of concentration of airborne radioactivity and Andersen impactor for particle size distribution. Some of the collected sampels were followed for their solubility in lung serum simulant for a period of about 200 days. The observed concentrations of the aerosols and their activity median aerodynamic diameters (AMAD) were 418 ± 443 Bq m^-3 (βγ), 1.28 ± 1.478 Bq m^-3 (∞) and 6.79 ± 0.4μm respectively. Analysis of the samples revealed the presence of ²³⁹Pu, U, ⁹⁰Sr and ¹³⁷Cs. The clearance half-life of the aerosols was the same (155 days) for all the isotopes (U, ²³⁹Pu, ⁹⁰Sr; ¹³⁷Cs). Calculation of effective dose equivalent for the clearance half-life and for 6.79 μm AMAD aerosols was carried out using the method recommended in ICRP-30. Annual effective dose equivalent of the workers, if no respirators were worn, worked out to be 3.2 mSv (320 mrem), the contribution from alpha emitters being about 63 per cent of the total. (author). 5 refs., 2 tables

[en] The amount of long-lived byproduct actinides (BPA) such as Np, Am, Cm etc. produced in the Th-²³³U cycle is found to be significantly less than that from presently used uranium fuelled reactors. It is shown that the potential biological hazard arising from HLW generated from thorium fuelled reactors wherein fusion breeder generated ²³⁸U-free-enriched-²³³U is used as the initial fissile component is much smaller than that from present day uranium fuelled reactors. (author). 8 refs., 2 figs

[en] Environmental radiation and radioactivity measuring instrumentation should meet the requirement of distinguishing very low levels of these normally present. Measurements require both direct radiation levels and radioactive levels in the environmental sample matrices. The paper describes the instrumentation and techniques used by the environmental survey laboratories operating at atomic power station sites in India. (author)

[en] The main source of radon and its progeny in a dwelling is the diffusion of radon gas from the soil. Basement rooms will have higher levels of radon. For a given source strength, the pressure inside the room and ventilation rate determine the radon levels. These parameters are influenced by the seasonal variations in the atmospheric conditions. A study of the seasonal variations of radon and its progeny levels in a basement room as well as in the outdoor air has been carried out. Both grab sampling and passive time integrated methods are employed. The results show that the seasonal variations occurring in the radon levels inside a dwelling should be taken into account while estimating the population dose. It is also seen that time integrated methods are preferred to spot sampling for more reliable assessment of the dose. (author). 1 tab., 5 figs

[en] The paper presents the studies made on the suitability of lyoluminescence technique as an analytical method for the identification of irradiated food stuffs. Powder milk, cinnamon, cardamom, clove, red chilly, cocoa, pepper, tea, coffee, turmeric and coriander showed lyoluminescence response when irradiated by a 10 kGy ⁶⁰Co and dissolved in luminol solution. Various dosimetric parameters such as effect of storage time, proportionality of the lyoluminescence response to dose etc were studied. (author). 1 tab., 3 figs

[en] The Personnel Monitoring Service Group is conducting countrywide personnel monitoring service for about 40,000 radiation workers by using Film Badge dosemeters and TL dosemeters. About 25000 film packs are processed every month. Two types of commercially available films are used and both the types have their own merits as well as some demerits. During monsoon Agfa Gevaert film packs are preferred as they are found to exhibit lesser latent image fading. However during monsoon the two films inside the Agfa Gevaert film pack tend to stick one another and their physical separation at the time of processing becomes extremely difficult resulting in damage of the films which makes dose estimation difficult. In the present paper a modification in the present Agfa Gevaert film pack to overcome this demerits is proposed. The experiment suggests that if a th in black paper is inserted in between the two films in each film pack at manufacturing stage, the sticking of films observed while using in high humidity areas could be completely avoided without affecting its dosimetric performance. It is felt that the modification in the Agfa Gevaert film pack as suggested in this paper will improve its usefulness in high humidity areas. (author)

[en] The concept of risk from radiation exposure in the International Commission on Radiological Protection (ICRP) publications is surveyed. The ICRP on radiation protection publication 26 is considered the basic document explaing the fundamental principles of the system of dose limitation. The ICRP publication 27 introduces a method of calculating the time lost from healthy life irrespective of the agent of harm either due to radiation accidents or any other course. The ICRP publication 45 mentions the 'unified index of harm'. It indicates that cancer mortality is a major contributor to industrial workers exposed to radiations. Risk estimates prepared will help in planning radiation work. (M.G.B.)

[en] The Cs-137 concentrations in different environmental samples measured by a high resolution HPGe detector are presented. As compared with the previous data, the levels of Cs-137 in different samples were found to be relatively low and hence probably do not pose any significant health hazards. These results will partly contribute to the programme of collection of base-line data for the 3 MW TRIGA Mark II research reactor at AERE, Savar, Bangladesh. (author). 9 refs., 2 tables, 2 figs