[en] The scientific activities and achievements of the Nuclear Research Center Democritos for the year 1980 are presented in the form of a list of 76 projects giving title, objectives, responsible of each project, developed activities and the pertaining lists of publications. The 16 chapters of this work cover the activities of the main Divisions of the Democritos NRC: Electronics, Biology, Physics, Chemistry, Health Physics, Reactor, Scientific Directorate, Radioisotopes, Environmental Radioactivity, Soil Science, Computer Center, Uranium Exploration, Medical Service, Technological Applications, Radioimmunoassay and Training. (N.C.)

[en] The scientific activities and achievements of the Nuclear Research Center Democritus for the year 1979 are presented in the form of a list of 78 projects giving title, objectives, commencement year, responsible of each project, developed activities and the pertaining lists of publications. The 15 chapters of this work cover the activities of the main Divisions of the Democritus NRC: Electronics, Biology, Physics, Chemistry, Health Physics, Reactor, Radioisotopes, Environmental Radioactivity, Soil Science, Computer Center, Uranium Exploration, Medical Service, Technological Applications and Training. (T.A.)

[en] The original version of this article unfortunately contains mistakes. The mistakes and corrections are described in the following list: 1) Author names were incorrectly presented. The correct format is shown above as well as in the below affiliation section.

[en] The scientific activities and achievements of the Nuclear Research Center Democritus for the years 1977 and 1978 are presented in the form of a list of 79 projects giving title, objectives, commencement year, responsible of each project and the pertaining lists of publications. The 14 chapters of this work cover the activities of the main Divisions of the Democritus NRC: Exploration of Radioactive Minerals, Computer Center, Environmental Radioactivity, Chemistry, Physics, Biology, Soil Science, Electronics, Reactor, Health Physics, Radioisotopes, Technological Applications and Medical Service. (T.A.)

[en] The basic considerations upon which the new revised Safety Analysis Report (SAR) for the GRR-1 will be based are presented. The format and the content the SAR will follow are given. A number of credible and less credible accidents is briefly analysed on the basis of present knowledge and experience for similar reactors, as well as the experience gained in the last 10 years of the GRR-1 operation at 5 MW. The accident caused by partial blockage of the cooling flow is considered to be the Maximum Credible Accident (MCA) for the GRR-1. The MCA is analysed and its radiological impact to the environment is estimated using conservative assumptions. (T.A.)

[en] This work deals with the geology and radioactivity of a part of the Serres Basin which is made up by the Tertiary sedimentary sequence, peculiar toward the western edge of Rhodope, with lignites occurring locally. The area is transected by three northwesterly trending major faults having a throw of over 150 m. The purpose of this work was the location of as many as possible areas exhibiting a radioactivity much higher than the normal background, as well as their comparison and classification in orders of magnitude. The background radioactivity in the area varies between 150 to 200 c/s; deviations higher than this range area considered to be anomalous. An area of 75 km² has been explored where 170 sites exhibiting high radioactivity ranging from 2 to 20 times the background have been located; description of these areas appears in the tables. Of the 170 sites 100 refer to lignite bearing argillaceous sandstone formations, while the rest of them consists of altered sandstones, fossiliferous limestones and other sedimentary sequences. (N.Ch.)

[en] Complete text of publication follows. Seismicity as a critical phenomenon has been actively discussed by many authors (e.g., Bak and Tang, 1989; Turcotte, 1997; Sornette, 2000; Rundle et al., 2003; Keilis-Borok and Soloviev, 2003). It has been shown that seismic electric signals (SES) and EQs reveal dynamic evolution characteristic to critical stage when their time series is analyzed in the framework of natural time introduced by the Varotsos' group (e. g., Varotsos, 2005;). Seismicity and geoelectric potential changes, possibly associated with the seismic swarm activity in 2000 in the Izu Island region, Japan, were analyzed in the framework of the natural time χ, which is an index of the k th event χ = k/N, where N is the total number of events (Uyeda et al., 2009). The Izu 2000 swarm activity lasted for about 2 months with some 7000 shocks with magnitude M≤3 and five M≤6 shocks, and was preceded by a pronounced electrical activity with innumerable signals that started 2 months prior to the swarm onset. It is shown, first, that the seismicity subsequent to the electrical activity approaches a critical stage a few days before the occurrence of the first M≤6 shock and, second, that the electrical signals also have the properties characteristic to the critical stage. Despite the big differences in time scale and numbers of electric signals and earthquakes, these features are similar to those in Greece. Furthermore, we investigate whether the above properties of seismicity were found also before 1995 Kobe earthquake, by using only seismic catalog without using SES data. When computations were started several months before the main shock, several true coincidences appeared approximately one month before the earthquake.

No abstract available

[en] The main object of this paper is the documentation and study of the main factors behind the spectacular diffusion of solar energy use for domestic hot water production in Greece. The time pattern of the diffusion of flat-plate solar collectors since its 'out of the blue' first appearance in 1974, shows that the diffusion rate grew exponentially at first, with the annual sales figure reaching 91,000 m² by 1980. A rate slow down in the early 1980s was followed by a brief period of explosive growth, with the annual sales figure reaching its peak value of more than 185,000 m² in mid-1980s. A rapid decline of the growth rate down to the present annual sales level followed. The installed solar collectors pattern has the characteristic form of an S-shape curve, representing the overall penetration of the flat-plate solar collector use for domestic hot water production in the Greek economy and society. This evolution has gone through an inflection point around 1987, i.e. at a time when about 1,000,000 m² of collectors had already been installed. By the year 2000, about 2,070,000 m² of collectors had been installed, with a tendency to level off by 2010, unless some the present conditions determining this phenomenon change. (author)

[en] The investigated area (approx. 200 km²) is confined within the limits of the strongly blastomylonitic Symvolon granodiorite. The effort made at this stage of research aimed first at the interpretation of the geochemical and radiometric anomalies resulted from earlier phases of exploration and second at the determination of the importance degree of the area. A large number of radiometrically anomalous zones, mainly in the NE part of the granodiorite, was localized, striking NW-SE and confined within fractures containing pyrite, in part or totally altered into hematite or limonite. Rock assays and phasmatometry results (γ-radiation) have shown that the high values of gross γ-radiation are due to uranium and also that a satisfying grade of chemical equilibrium exists in the area. Rock samples collected from anomalous zones and analyzed for total uranium gave values between 15 ppm and 400 ppm. The results from the present phase of research have shown that, mainly in the NE part of the area, a tectonic control of the uranium mineralization (along fractures striking NW-SE) is present and also that there may exist considerable uranium concentrations. (N.C.)