No abstract available

[en] Current regulatory requirements for the use of x-ray optics equipment in factories are compared with the 19-year-old Guidance Notes for their use in research and teaching establishments. The difficulties in drafting new legislation to cater for both areas of use are discussed and the proposed regulations and approved code of practice having a direct bearing on x-ray optics equipment are reviewed. Comment is made concerning the proposed Health and Safety Executive document, ''Radiation Safety in the use of X-ray Optics Equipment, which will give practical advice and guidance on cost effective methods of achieving the regulatory objectives. The costs involved are unlikely to be significant for the majority of users and implementation of the proposed legislation should not restrict the use of x-ray optics equipment. (author)

[en] A method, using a radioactive source and scintillation detector, to assess a value of lead equivalence for materials which may be provided for radiation shielding from diagnostic X-rays is described. Such values have been compared with those determined by measurements of broad beam X-radiation transmission at generating kilovoltages in the range 60 kV to 150 kV for wall sections built from conventional building materials. The results demonstrate the validity of this new method which has proved to be a very simple and quick means of assessing shielding quality. (author)

[en] Small quantities of radionuclides are discharged in airborne effluents during the normal operation of nuclear installations. The dispersion of these nuclides in the atmosphere and their subsequent transfer through various sectors of the environment leads to the irradiation of the population. The collective dose to the UK population from airborne discharges in one particular year, 1978, from UK nuclear installations is estimated. The discharges in that year are typical of those in the recent past. Consideration is given to the contribution made by each type of establishment (eg, nuclear power stations, reprocessing plants) and the nuclides which contribute significantly to the collective dose are identified. The distributions of the collective dose in time and among individuals in the exposed population are important features in determining the significance attached to it and both aspects are discussed. The collective dose can be used as a measure of the health detriment associated with the discharge practices considered and is one of several quantities to be taken into account in assessing them. The collective doses from airborne discharges are finally contrasted with those from other sources of exposure of the population. (author)

[en] Comparative studies of the risks of electricity generating systems show that nuclear power is safer than electricity from coal or oil, taking account of each system as a whole. The comparison must not suppress issues of real significance to decision makers, who might, for example, weigh in different ways, accidental deaths, occupational cancers, and small probabilities of potential major events. The conclusion is often met with surprise or scepticism. The reasons are examined. They bring out both the differential attitudes of sectors of the public to various risks, and the nature of decision-making about public and occupational risk. (author)

[en] Recently the NRPB, under contract to the Health and Safety Executive, and in association with the British Railways Board, has assessed the radiological impact of consignments transported on the British Rail system. The work has shown the radiation exposure of British Rail staff and of the public to be low. This paper identifies the types of radioactive materials transported by rail, outlines the methods used to assess the doses to persons exposed and presents the results of these assessments. (author)

[en] In 1977, the Methodist Hospital of Lubbock, Texas, sold a 14 year old Picker C-3000 therapy unit to Mexican Centro de Juarez, instead of taking up the Picker option of dismantling, removal and safe storage. The device was never used for research or treatment, and the resulting accident after its dismantling and dispersion of the parts by unknown persons in November 1983 is described in outline. (U.K.)

[en] This group of letters by P.R. Webber, J. Rotblat, P. Steadman and O. Greene answer J.H. Martin's criticisms (J.Soc. Radiol. Prot. 4(4)1984) of several of the authors' publications, notably London after the Bomb, Doomsday: Britain after Nuclear Attack, and advice given by the MRC Committee on Protection against Ionising Radiation. J.J. Martin replies. (U.K.)

[en] Some of the biological effects of ionising radiation occur only at doses above some threshold, others appear to occur at all levels of dose, the probability of occurrence decreasing to zero only as the dose decreases to zero. Dose limits set below the relevant thresholds provide protection against the former type of effect but dose limits alone are not sufficient to give protection against non-threshold effects. For these, the dose limits should be selected at a level such that continued higher exposure could not be justified and further measures should be taken to keep doses as far below these limits as can reasonably be achieved. The dose limits safeguard those whose exposures lie at the high end of the distribution while the remaining measures serve to reduce the exposures wherever they fall within the distribution. Dose limits relate to controllable situations and different considerations have to apply in accidents or in the management of solid radioactive wastes where rare events may give rise to foreseeable but not directly controllable exposures. (author)

[en] Current methods of classifying working areas in which unsealed radioactive materials are handled, are based primarily on surface contamination levels. The validity of the concept and its feasibility are examined and a new method proposed, which is based on the quantity of a radionuclide handled. The classifications are compatible with those used elsewhere in the field and the system has been in used, very successfully, since 1979. (author)