Forschungspartnerschaft Grundlagenorientierte Mineralrohstoffforschung – ein neues Instrument der Rohstoffforschung

By establishing the “Minerals resources research partnership” a new innovative financing instrument was developed, which allows to finance small research projects in the forefront of the ‘classical’ research programs. The partnership is executed responsibly by the Geological Survey of Austria co-operating with universities and other partners on commodity research topics. The paper briefly describes the eligible key aspects, guidelines and the modality of granting of the funds.     

Stärken und Schwächen internationaler Vorratsklassifikationssysteme

There are numerous mineral resources classification systems worldwide (USGS, JORC, PERC, SAMREC, CRIRSCO, UNCF). On the one side the USGS system fulfils global reporting in a proper way. On the other side the “national” systems are more appropriate for detailed companies reporting. However, some rare metals are not economically concentrated in mineral deposits. Extraction is done by further processing of residues of metallurgical plants, fly ash or other industrial waste. These rare metals are not considered in the resource classification in a satisfying manner. As a matter of fact, information concerning “lifetime” of those metals is more than speculative. The paper deals with strengths and weaknesses of the most important international classification systems and makes suggestions for improvements. There is a strong evidence for supporting the classification system of the United Nations, which is under revision presently, as it can fulfil all purposes properly.     

Stainless steel containers for the storage of low and medium level radioactive waste

Corrosion investigations have been performed on the austenitic structural steel AISI 304L, in comparison with the structural steel AISI 316L, in an aerated and a de-aerated solution, which was leached from low and medium level radioactive waste. On the basis of measured potentio-dynamic anodic polarization curves and the results of cyclic polarization tests, it was found that both types of steel, as well as the corresponding welds, had a high pitting potential and a high protective potential, which means that they have a strong tendency to form a compact and corrosion-resistant passive film. The repassivation capability of both types of steel prevents the occurrence of stress corrosion cracking at the level of concentration of chloride ions which corresponds to the described type of waste, whereas absorbed atomic hydrogen does not reduce toughness or cause hydrogen embrittlement. The results of the research work confirmed that it is possible to use AISI 304L structural steel for the construction of containers for the temporary, 30-year storage of low and medium level radioactive waste.     

Nonspecular reflection of beams from liquid-solid interfaces

Nonspecular reflection plays an important role in acoustic beam interaction with fluid-immersed elastic media. Such anomalous reflection is attributed to the strong interaction which occurs when the incident beam is phase-matched to one of the leaky waves supported by the structure. The properties of the incident beam as well as those of the interface geometry exert a marked influence on the observed nonspecular return. Previous investigations have been limited to rather special beam and interface conditions. The present study removes many of these limitations by allowing for arbitrarily collimated beams incident on plane and (cylindrically) curved layered geometries as well as simultaneous excitation of multiple leaky waves. By use of the complex source point (CSP) method for modeling quasi-Gaussian beams, the reflection problems are solved rigorously by wavenumber spectral decomposition. They are then reduced by asymptotic techniques to yield physically meaningful wavefield contributions, which explain the phenomenology and also allow efficient computation. The accuracy of the CSP asymptotic algorithms, and that of more restrictive conventional algorithms, is assessed by comparison with purely numerically generated reference data. The results establish the accuracy and versatility of the CSP strategy for a broad range of beam-interface conditions. While the present study is for two-dimensional problems, the method has also been extended to the three dimensional case. The data base generated by this method is the first step toward developing a strategy for extracting from data information about the interface conditions.