Determination of 75Se, 95Zr, 237Np and 241Am activities in Boom Clay samples from laboratory migration experiments using gamma-ray spectrometry

Percolation tests (i.e. routine laboratory migration experiments) have been performed to evaluate the diffusion behaviour of a number of long-lived radionuclides in Boom Clay, a candidate geological host formation for high level radioactive waste (HLW) in Belgium. Among the many potentially hazardous radionuclides under investigation are 79Se, 93Zr, 237Np, 241Am and 243Am. Actinide migration experiments have been carried out with 237Np and 241Am, while for the studies with Se and Zr the radioisotopes 75Se and 95Zr were used. Their transport patterns in the Boom Clay were examined using a combination of a NaI(Tl) detector and High-Purity Ge detectors either on the dissolved matrix (237Np, 241Am) or directly on the clay (75Se, 95Zr).

Attitudes towards population trends and population policy in the Netherlands, compared with some data from other Western European countries.

PIP: In the netherlands fertility has been below replacement level for the last decade. The overall age specific fertility rate is at an all time low of about 1.5. The relatively young age structure of the population implies a continuing population growth for some time, but at present it is less than 0.4% per year. In the coming years the Netherlands will be confronted with a considerable demographically determined increase in the labor supply, a consequence of, compared to neighboring countries, an initially high birthrate. It is in light of this demographic transition situation that the results of the 1983 survey of the Dutch population aged 20-64 have to be considered. The representative sample of 952 people were interviewed about their knowledge and opinions concerning certain aspects of the population issue and about their attitudes with regard to demographically relevant government politics. The survey primarily investigated the acceptance (with regard to opinions and behavioral intentions) of population/family policies in relation to reproductive behavior. This discussion fcuses on prevalent attitudes with respect to fertility trends, future population growth and decline, aging, and more direct government involvement. For the sake of illustration some findings are compared to results from recent surveys conducted in Belgium, France, and the Federal Republic of German. Te majority of those interviewed had some knowledge of the decline in the number of births which has occurred since the 1960s. The drop in the number of births which actually occurred was considered positive by 47% of those interviewed and negative by 13%. Compared to the results of a survey held in 1980 in the Dutch speaking part of Belgium, the large pecentage (40%) of Dutch people w had no definite opinion is notable. In the belgian survey, the same question resulted in 54% of those questioned judging the decline as positive, 29% negative, with 17% having no opinion. A reduction in the size of the population as a consequence of birth trends was viewed as a positive development by 1/3 of the population and as a negative development by another 1/3. 82% of the respondents were acquainted either with the fact that in the next 15 years the number of popple aged over 65 will increase considerably. 49% viewed this trend as an outright problem, while 15% considered it in a positive light. There was a certain consistency between the attitudes with respect to aging and those with respect to the fertility decline. According to 40% of those included in th Survey, the government may (in the most extremity) take it upon itself to influence the size of the population. With regard to the matter of whether the government may have a hand in determining the number of births, the answers were more reserved. Only 19% agreed that the government can (if need be).^ieng

[Reproduction and survival: family building and population growth in past and present]. / Reproduktie en overleven: gezinsvorming en bevolkingsgroei vroeger en nu

PIP: The authors examine factors affecting the average number of surviving children per woman. Variables considered include contraceptive use, frequency of intercourse, and mortality. Differences in fertility levels and contraceptive use between the preindustrial era and the present are discussed. The relationship between population growth and quantitative and qualitative aspects of existence is studied^ieng