Table of contents

This paper, which is based upon a seminar presentation, examines the development of the concept of detriment by ICRP and the techniques available for quantification, especially cost-benefit analysis and multi-attribute utility analysis. Work in a number of areas in which quantification of detriment is needed is then examined to provide illustrations of how the topic is proceeding to practicality and use. The areas covered are the calculation of total health detriment, the special approach to detriment in the medical field and detriment assessment in the accident and emergency field.

In the UK, the discharge of radioactivity to the environment by nuclear power stations is closely regulated. In addition to the setting of numerical limits on discharges, the UK approach requires that 'best practicable means' be adopted to reduce discharges. This is somewhat analogous to the ALARP or ALARA approach in other areas of radiological protection. Separate regulations govern areas such as radiation doses and the generation and accumulation of radioactive waste on the site. The author highlights the issues facing a UK operator when preparing evidence to justify to the various regulatory bodies a particular level of discharge to the environment. The author explains that the Regulations demand optimisation, rather than minimisation, of discharges and then shows how it should be possible to justify a waste management strategy to the Regulators by using agreed values in a cost-benefit analysis. The author stresses the importance to the nuclear industry of securing a consistent, clear and objective approach by the Regulators and argues that the regulation of the industry under legislation relating to the minimisation of harm to people and environment should not become confused with the equally important, but separate, issues relating either to national and international political pressures or to public relations strategies.

The repeat profile of an X-ray department in a developing country was analysed monthly between July 1989 and June 1990. Results showed an average repeat rate of 3.7% for the period of study. The main causes of film repetition were: equipment fault, 33.9%; radiographer's fault, 27.4%; film fault, 19.3%; processing fault, 10.8% and patient's fault, 8.6%. The average repeat rate in the first six months of study reduced by 50% in the last six months. This was due to the effectiveness of implementation of corrective actions. The overall repeat rate was found to correlate well with both the equipment fault and radiographer's fault with correlation coefficients, r, of 0.94 and 0.91, respectively. It is expected that a further reduction in the repeat rate will be obtained after the introduction of quality assurance programmes.

The objectives of individual monitoring of exposure to external radiation are discussed, as are the results of surveys of the workplace photon radiation fields at the Sellafield Works of British Nuclear Fuels plc. It is proposed that the most suitable normalisation of the personal dosemeter employed is that which gives the best estimates, on average, of the effective dose equivalent for the practical occupational fields.

During the course of personal radiation monitoring, the results of dosemeter measurements may fall below a threshold level and the numerical value of the dose estimate is not retained in the record. A method of estimating such doses is presented based on the presumption of a log-normal distribution of received doses; the fraction of dosemeter results for a period recorded below the threshold level together with the population geometric standard deviation is used to provide individual total dose estimates. Sample data sets of dosemeter results from two establishments are shown to have similar distributions with the combined sample having a geometric standard deviation of 2.07+or-0.44. Data are presented to show the population dose estimates are unbiased and the total dose estimate for any person is unlikely to deviate from the true value by more than about 20% due to individual variation in distribution of dose from that for the population.

The author discusses the important changes in the 1990 recommendations of the ICRP from the 1977 publication. The additions mainly cover biological aspects and radiation protection frameworks. Various dose limits are also covered.