Increased Accuracy of the Binding Energy of K- and L-Subshell Electrons in Krypton from Re-analysis of Experimental Data: Importance for Determination of the Neutrino Mass

Analyzing thoroughly K and L X-ray transition energies, results of the former L-shell photoabsorption study and M subshell binding energies from photoelectron and optical spectroscopy, we determined the following electron binding energies in gaseous krypton: 14 327.26(4) eV for the K-shell and 1 921.4(3), 1 731.91(3) and 1 679.21(3) eV for L₁-, L₂-, and L₃-subshells, respectively. These accurate values of electron binding energies are important for energy calibration of the next generation tritium -decay experiment KATRIN with sub-eV sensitivity for the electron-neutrino mass.     

Matrix and fissure water movement through unsaturated calcareous sandstone

Evaluation of pollution endangering groundwater resources beneath fractured sediments may be achieved by estimating the transport rates and recharge amounts of both the matrix and the fissure components. This study examines the transport of water by matrix and fissure flow in the unsaturated zone using environmental tritium as a natural tracer. A 35-year record of tritium concentration along 40 m calcareous sandstone column was reconstructed. It was found that on the average, 40 mm yr¹ (8% of the yearly rain) percolated downward through the matrix pores at a velocity of 1.1 m yr¹. An additional amount of more than 20 mm yr¹ (more 4% of the rains) percolated rapidly through fissure network. These field data fit and support the model proposed by Wang and Narashimham (1985) that the bulk of the water movement under unsaturated conditions occurs through interconnected pores in the matrix.     

中国TBM氚处理系统设计阶段的安全分析

以氚释放为安全分析的重点,根据氚多重包容的安全概念设计,分析了TBM氚处理系统的一种布局方式。从安全的角度进行了TBM氚处理系统的功能和材料分析,根据运行状态或危险给出了TBM氚处理系统可能存在的四个不安全状态,确定了在不同的系统状态工作人员处于不同的应急水平,应采取不同的应急措施。最后,在上述研究的基础上进行各级氚包容系统氚释放的预先危险性分析(PHA),得到了事故原因和危害后果,并提出预防氚释放危险的安全措施。     

聚变-裂变混合堆系统在能源战略中的地位及其设计中若干问题的分析

简要描述聚变-裂变混合堆在长期能源发展战略中的地位,着重计算分析具有不同类型的聚变堆芯和包层的混合堆生产电能和可裂变核燃料的能力,研究不同类型聚变-裂变混合堆与其支持的卫星堆(如压水堆)组合燃料循环系统生产电能的能力.指出以天然铀或贫化铀为燃料,水冷却的包层设计是一种经济可行、技术风险较小的设计方案.     

A Procedure for Determination of Tritium in Potassium

Abstract

A procedure has been developed for the quantitative analysis of potassium for its tritium content. This procedure consists of dissolving the highly reactive alkali metal in an inert liquid containing a small amount of ethanol and then analyzing the resulting solution for its tritium content by classical methods. Techniques previously used for sodium analysis are reviewed and discussed as they apply to the more reactive potassium.     

Technogenic Tritium in Central European Precipitations

An overview of environmental aspects of the tritium method is given. Temporal and local variations of the specific tritium activity of precipitations, particularly the decay of the bomb peak as well as the continential and latitude effects, are used to subdivide the tritium content of precipitations in bomb tritium and technogenic tritium for the example of the measurement series of Freiberg. Technogenic tritium is shown to have prevailed from the beginning of the eighties, whereas the emission of technogenic tritium has strongly decreased in Europe since the middle of the seventies.     

3H-Streptomycin durch Wilzbach-Reaktion

Zur Klärung spezieller Fragen des Transportes von Streptomycin in Pflanzen sollte radioaktiv markiertes Streptomycin eingesetzt werden. In der Mehrzahl der in der Literatur publizierten Untersuchungen (Engelberg und Artman [1]; Davey und Papavizas [2]; Hancock [3]; Das, Chatterjee und Roy [4]; Goodman [5]; u. a.) wurde ein [¹⁴C]-Streptomycin-CaCl₂-Komplex von MERCK, SHARP und DOHME Research Laboratories, USA benutzt. André [6] berichtete über die Herstellung von [³H]-Dihydrostreptomycin durch katalytische Anlagerung von ³H an Streptomycin. Bonventre, Hayes und Imhoff [7] arbeiteten mit uniform ³H-markiertem Streptomycin von Nuclear Research Chemicals, Orlando. Über Herstellung und Reinigung wurden keine Angaben gemacht.     

Two-step synthesis of ethylene glycol-D6 via isotope exchange of glycolic acid

Tracers can be used to monitor emissions of leachate from landfills in order to detect hydrological pathways and to evaluate environmental pollution. We investigated the stable carbon isotope ratio (δ¹³C–Σ CO ₂) in dissolved inorganic carbon and tritium (³H) in water, in addition to the tracers of pollution commonly found in relatively high concentrations in leachate, such as chloride (Cl), organic matter (COD), nitrogen (total and NH₄–N), iron (Fe), electrical conductivity (EC) and pH. The sampling was performed at seven landfills in the south-eastern part of Norway during a period of 5 years. The objective was to evaluate the potential for tracing leachate in the environment with emphasis on groundwater pollution. By measuring the δ¹³C–Σ CO ₂ in leachates, groundwaters and surface waters, the influence of leachate can be identified. The value of δ¹³C–Σ CO ₂ varied from?5.5 to 25.9 ‰ in leachate, from?25.4 to 14.7 ‰ in groundwater and from?19.7 to?13.1 ‰ in creeks. A comparison of the carbon isotope ratio with COD, EC and the concentrations of total and NH ₄–N, Cl and Fe showed that δ¹³C–Σ CO ₂ is a good tracer for leachate due to higher sensitivity compared to other parameters. The mean concentrations of all the studied parameters were higher in the leachate samples; however, only the carbon isotope ratio showed significant differences between all the groups with strong and middle pollution and samples with low pollution, showing that it can be used as a convenient tracer for leachate in groundwater and surface water. The carbon isotope ratio showed strong correlation between nitrogen, EC and bicarbonate, but not with pH. Tritium was only sporadically found in measureable concentrations and is not considered as a suitable tracer at the sampled locations.     

Methoden zur Bestimmung der Radiaoktivität von verschiedenen Tritium und 14C-doppeltmatkierten Proben

Es wurde eine Methode zur Radioaktivitātbestimmung von Titrium- und ¹⁴C-markierten Substanzen auf Chromatographie und Pherogrammpapier mit dem Flūssigketisszintillationsspektrometer ausgearbeitet. Mit dieser Methode Können bei einem statistischen 2 σ-Fehler von höchsten ± 15% doppeltmarkierte Proben mit einem T/¹⁴C-Verhältnis von höchsten ½ gezāhlt werden. Weiterhin wurden fūr die Radioaktivitätsbestimmungen im Flūssigkeitsszintillationsspektrometer des T-Hamamelosehydrazons und der beim Abbau entstehenden T-markierten Spaltprodukte optimale meβbedingungen sowie die erforderlichen Eichkurven erstellt.     

Flüssigszintillationsmessungen wäßriger, 14C- oder 3H-haltiger Proben im Szintillationscocktail auf Toluol-Basis

Auf der Grundlage von Untersuchungen zur Mischbarkeit des ternären Systems Toluol/Methanol/Wasser wurde für Szintillatorcocktails auf Toluol-Methańol-Basis eine solche Zusammensetzung ermittelt, bei der sich ¹⁴C- oder ³H-haltige Proben in homogener Verteilung mit dem LS-Spektrometer messen lassen. Bei den mit einer HClO₄/H₂O₂-Mischung aufgeschlossenen Blut-Lösungen lag die optimale Probenmenge pro Meßküvette infolge des stärkeren Quencheffektes niedriger als in Wasser. Außerdem ist dabei der Einfluß der Energie der emittierten ß-Strahlung zu berücksichtigen.