[en] The nuclear reactor building is required to be constructed on a bedrock stratum in Japan. According to the seismic analysis for the structural design, it is indicated that the base mat uplift occurs partially. The tests, therefore, were performed to elucidate the uplift phenomenon of the reactor building through fundamental experiments which consist of two parts: the laboratory test using the shaking table and the field test using the exciter and hydraulic jack. This paper describes the laboratory test. Based on test and analytical results, estimations on the following subjects have been made: input level and contact ratio, contact ratio and response spectrum and effects due to the simultaneous horizontal and vertical excitation. The validity of the present design method has been ascertained

[en] Brief item

[en] Models of long-term environmental change are described with regard to the assessment of low and intermediate level radioactive waste disposal sites. For shallow repositories, containing low level waste only, the time to the next glaciation needs to be considered, but for deeper repositories the occurrence of multiple glacial cycles, which may change the hydrogeological context of the repository, needs to be modelled. The models use Monte Carlo simulations in which realistic sampled sequences of discrete climate states are derived for each simulated future. For each sequence, environmental changes are determined from a series of generalised sub-models of erosional, depositional and hydrogeological processes. These models also account for the crustal response to glacial advance and retreat. Human intrusion effects are simulated but are not fully integrated with the climate-driven sub-models. (author)

[en] The input motion in the seismic design of a nuclear power plant is generally defined by peak ground acceleration and by a free field response spectrum characterized by a certain standard shape. Usually, the peak ground acceleration is obtained as a result of a site specific seismic risk analysis using seismological variables such as Richter magnitude and epicentral distance. The standard shape of the response spectrum could be that defined by IAEA's Safety Guide 50-SG-SI (IAEA, 1979) or similar. This approach could bring along a substantial cost in the seismic engineering effort and, in some cases, non-realistic designs for specific sites, specially when referred to low seismicity zones where historical information is not available. This paper reports on a new approach (Riera et al., 1986 and 1987) is applied to the seismic analysis of a specific site located in the Eastern region of Argentina, next to the Atlantic coast, thus obtaining the horizontal acceleration spectrum mentioned above. The method is based on the selection of random variables (earthquake magnitude and epicentral distance), which are needed to describe the motion of the base rock, as ordinates of the seismic response spectrum, on the basis of regression studies

[en] The hybrid modeling method (Gupta and Penzien 1980) and associated analysis procedure for solving a three-dimensional soil-structure interaction problem was developed by Gupta and Penzien (1981) and Gupta et al.(1982). Subsequently, successive modifications have been made to the original modeling method and analysis procedure allowing more general treatment of the SSI problem (Penzien, 1988). Through many correlation studies of field test data obtained under forced-vibration and earthquake-excitation conditions, it has been shown that the HASSI programs can effectively predict the dynamic response of a soil-structure system, if realistic soil parameters are adopted. In the above, the entire structure-foundation system is considered to respond in a linear fashion. Since the reflected three-dimensional waves at the soil-structure interface decays very rapidly with distance away from the structure (Katayama, 1987 (a)), the response of the soil close to the base of the structure may greatly affect its response; therefore, proper modeling of the non-linear soil behavior characteristic is essential. The nonlinear behavior of near-field soil has been taken into consideration in HASSI-7 by the standard equivalent linearization procedures used in programs SHAKE and FLUSH

[en] The radioactivity background level of enviromental medium around a pulsed reactor for 5 km and external penetrating radioactivity dose level for 10 km are given. mediums measured include air, water, soil, organisms, fallout, etc

[en] The paper reports results of a study on the seasonal distribution and abundance of jelly fishes in the coastal waters of Kalpakkam in the context of their ingress into the cooling system of a power plant. Three species of jelly fishes Dactylometra quinquicirrha (L. agassiz), Crambionella stuhlmanni (Chun) and Chiropsalmus buitendijki (Horst) were found in such abundance as to cause blockage of the cooling water intake screens. The seasonal variation in the incidence of the jelly fishes clearly showed that the periods of maxima and minima were different for each species. During the period of study (February 1988 to April 1989) three maxima were noted - May, July and October. On any given single day, maximum quantity of jelly fishes collected from the travelling screens was 29 tonnes (21 July 1988). The data are discussed with respect of (i)qualitative and quantitative variations in the ingress of jelly fishes at Kalpakkam, (ii)operational problems associated with jelly fish ingress and (iii)possible approaches to combat the problem. (author). 1 tab., 4 figs., 9 ref s

[en] This paper presents briefly some aspects thought to be important in what concerns the diminution of the total impact that the realization and operation of nuclear facilities bring about. Particularly, highlighted is the reconstruction of ecological equilibrium, the change of which is induced by the whole chain of activities implied in the nuclear fuel cycle, starting with uranium extraction from uranium ores, up to its use in the nuclear power plant. Predictive estimates are attempted in connection with cessation of implied activities. As solutions for ecological reconstruction, the following are considered: land reclamation by re-shaping the slopes and by covering with fertile earth the sterile dumps resulting from exhausted uranium mines and by implanting fresh vegetation with deeply penetrating roots able to stabilize the ground; cleaning the access galleries of the access and ventilation wells; drying and draining the access water in bulk solid wastes and in the open decantation pools; slope stabilization, covering with fertile soil and grass and bush cultivation; decontamination of buildings; utilisation of inactive and isolated mines for low and intermediate activity radioactive waste disposal; closing and covering with layered structure of earth, draining materials, clay, fertile soil and grass and bush cultivation of organized containerized low and intermediate activity radioactive waste repositories; long-term monitoring of surfaces and underground waters at closed mines, decantation pools underground or overground radioactive waste repositories; storing the plutonium contaminated soil in trenches covered by a layer of non-infested earth of minimum 5 m thickness and in-situ vitrification by means of a high intensity current. These are principles set forth by IAEA concerning the radioactive waste management

[en] During the period comprised (1983-1984) the zone being studied was limited to an area of 3 km around the potential site of a future nuclear facility. The measurement of dose rate was made with a highpressure ionization chamber of the RSS-111 type, with a measurement range of 0-1000 μR/h and ± 0,1 μR/h error. At the same time, integral dosis in the period was measured by using LiF thermoluminescent dosimeters. The results obtained can be correlated (ρ=0,72) and they range from 5,1μR/h to 6,3 μR/h. Analyses were also made of soil, pasture, milk, water and silt samples taken from a net of places established in the zone. The content of natural radionucleids (⁴⁰K, ²²⁶Ra, ²³²Th) and of ¹³⁷Cs by spectrometric measurements of low background was determined. The content of ⁹⁰Sr in the samples was found through a method of radiochemical concentration and low background radiometric measurement. The results lead to preliminary conclusions about the radiological situation in the zone. The concentration values of natural and artificial radionucleids confirm that the radioactive environmental background of the zone under study only receives natural sources and radionucleids originated in artificial sources coming from the global atmosteric pollution. (author). 8 refs

[en] Data were gathered in various habitat types to determine annual fluctuations in species diversity and relative abundance, breeding densities, reproductive success of White-necked Ravens and Harris Hawks, fall and spring migrant species and to collect voucher specimens for the site. Four Emlen transects were surveyed in four habitat types during the summer of 1980. These transects were used monthly in May, June and July to determine densities of breeding and non-breeding birds. Active White-necked Raven and Harris Hawk nests were located by checking all conspicuous nests. The nests were checked several times during the nesting stage to determine nest success. During 1980, eleven new species and two new families were added to the list of birds seen on or near the WIPP site. The list now totals 133 species representing 38 families. White-necked Raven nesting success was slightly lower in 1980 than in 1979. Average clutch size in 1980 was 5.5, which is 3.5% less than in 1979 and 19% greater than in 1978. The average number of birds fledged per nest was surprisingly similar over the past three years despite fairly large climatic differences. Success of Harris Hawk nesting was very low in the autumn of 1980 due principally to bad weather. The overall density of breeding birds was lower in 1980 than in 1979 in all habitat types. The overall density was also lower in 1980 than in 1978 in all habitat types except mesquite-grassland. Many species showed larger year-to-year fluctuations in numbers. Mourning Dove density, for example, dropped from 76.9 to 11.2 individuals per square kilometer in the hummock-mesquite habitat. Voucher specimens have been collected for 69 of the 133 species seen on the Los Medanos site