Radiological aspects of the usability of red mud as building material additive.

Several researchers have examined and achieved favourable results in connection with the building industry's use of red mud extracted in large quantities from the processing of bauxite. These days more and more precedence is being given to limiting the radiological dose to the population. In this study carried out in Hungary, the use of red mud, bauxite, and clay additives recommended for the production of special cements, were examined from a radiological aspect. (226)Ra and (232)Th activity concentrations measured in Hungarian bauxite, red mud and clay samples were significantly similar with the levels for such raw materials mentioned in international literature. Taking radiation protection aspects into consideration, none of these products can be directly used for building construction. Taking Hungarian and international values into consideration, a small amount of red mud, not exceeding 15% could be used for brick production, for example as a colouring material. However, beyond this amount the standards for building materials would not be met. For the production of cements an even stricter limit needs to be determined when both bauxite and red mud are used.

Performance assessment model development and parameter acquisition for analysis of the transport of natural radionuclides in a Mediterranean watershed.

This paper describes the methodology developed to construct a model for predicting the behaviour of the natural radioisotopes of U, Th and Ra in a Mediterranean watershed. The methodology includes the development of the performance assessment model, obtaining water flow and radiological parameters based on experimental data and analysis of results. The model, which accounts for both water flows and mass balances of the radionuclides in a semi-natural environment, provides assessments of radionuclide behaviour in grassland and agricultural soils, rivers and reservoirs, including the processes of radionuclide migration through land and water and interactions between both. From field and laboratory data, it has been possible to obtain parameters for the driving processes considered in the model, water fluxes, source term definition, soil to plant transfer factors and distribution coefficient values. Ranges of parameter values obtained have shown good agreement with published literature data. This general methodological approach was developed to be extended to other radionuclides for the modelling of a biosphere watershed in the context of performance assessment of a High Level Waste (HLW) repository under Mediterranean climate conditions, as well as for forecasting radionuclide transport under similar Mediterranean conditions that will occur in the future in other areas. The application of sensitivity and uncertainty analysis was intended to identify key uncertainties with the aim of setting priorities for future research. The model results for the activity concentration in the reservoir indicate that for (238)U and (230)Th the most relevant parameter is the initial concentrations of the radionuclides in the reservoir sediments. However, for (226)Ra the most important parameter is the precipitation rate over the whole watershed.

Beverages: bottled water. Direct final rule.

The Food and Drug Administration (FDA) is amending its bottled water quality standard regulations by establishing an allowable level for the contaminant uranium. As a consequence, bottled water manufacturers are required to monitor their finished bottled water products for uranium at least once each year under the current good manufacturing practice (CGMP) regulations for bottled water. Bottled water manufacturers are also required to monitor their source water for uranium as often as necessary, but at least once every 4 years unless they meet the criteria for the source water monitoring exemptions under the CGMP regulations. FDA will retain the existing allowable levels for combined radium-226/-228, gross alpha particle radioactivity, and beta particle and photon radioactivity. This direct final rule will ensure that the minimum quality of bottled water, as affected by uranium, combined radium-226/-228, gross alpha particle radioactivity, and beta particle and photon radioactivity, remains comparable with the quality of public drinking water that meets the Environmental Protection Agency's (EPA's) standards. FDA is issuing a direct final rule for this action because the agency expects that there will be no significant adverse comment on this rule. Elsewhere in this issue of the Federal Register, FDA is publishing a companion proposed, rule under the agency's usual procedure for notice-and-comment rulemaking, to provide a procedural framework to finalize the rule in the event the agency receives any significant adverse comments and withdraws this direct final rule. The companion proposed rule and direct final rule are substantively identical.

The 1999 Lauriston S. Taylor lecture--back to background: natural radiation and radioactivity exposed.

I am profoundly grateful for being chosen as the twenty-third presenter of the Lauriston S. Taylor Lecture, and I share this honor with a list of distinguished scientists, including my husband, who pay tribute to the premier leader in radiation protection. In 1938, Laurie was working for the National Bureau of Standards and chaired the Advisory Committee on X-ray and Radium Protection, a group of 8 persons, who set the pace for all forthcoming radiation standards. NBS had, since 1913, been standardizing essentially all of the radium offered for sale in the U.S., and the problem arose to revise the handbook on proper conditions for handling radium based on the then current knowledge. This resulted in Handbook 23 (1938) superseding the 1934 work. At the time Laurie was a scientist working in the measurements side of radiation and though he contributed much to that field, his name is inseparably linked with guidance in radiation protection. Today we pay tribute for his leadership that he carried out with intelligence, grace, and personal warmth. My talk today deals mostly with measured data for naturally occurring internal radiation emitters and how these data can be used for predictive purposes in estimating the dose and risk from internal body contamination. This stresses the "and Measurements" part of the Council's title. The topic of this year's NCRP Annual Meeting is "Radiation Protection in Medicine: Contemporary Issues." I believe that physicians and State and Federal agencies will have to cope with complaints following various exposure situations resulting from the cleanup of background radionuclides during closure at nuclear facilities, military use of radioactivity, and occurrences of high natural background in some locations. They will find comfort in the knowledge that existing background radiation data can be the basis for predictions of realistic dose and risk in most situations.