No abstract available

[en] To realize the safety of personnel and environment systems and components of nuclear facilities are classified according to their potential danger into safety classes. Based on this classification different demands on the manufacturing quality result. The objective of this work is to present the standardized method developed by NUKEM Technologies Engineering Services for the categorization into the safety classes restricted to Non-reactor nuclear facilities (NRNF). Exemplary the methodology is used on the complex Russian normative system (four safety classes). For NRNF only the lower two safety classes are relevant. The classification into the lowest safety class 4 is accordingly if the maximum resulting dose following from clean-up actions in case of incidents/accidents remains below 20 mSv and the volume activity restrictions of set in NRB-99/2009 are met. The methodology is illustrated using an example. In short the methodology consists of: - Determination of the working time to remove consequences of incidents, - Calculation of the dose resulting from direct radiation and due to inhalation during these works. The application of this methodology avoids over-conservative approaches. As a result some previously higher classified equipment can be classified into the lower safety class.

No abstract available

[en] Electron-impact ionization of ions is one of the most fundamental processes in every kind of plasma. Especially in high-temperature plasmas-whether in laboratory (nuclear fusion) or in astrophysics (atmosphere of stars)-atoms become ionized into multiply-charged ions by electron impact. The main purpose of authors' investigations is to unravel the contributions from different ionization mechanisms-like direct ionization (one-step process), excitation-autoionization (two-step process) and inner-shell Auger processes to the cross sections of single and multiple ionization of highly-charged ions. As the experimental database is still rather small, theoretical cross sections are often used for the calculation of different plasma parameters. Cross sections for ions with an outer 4f shell are usually small and experimental data is needed in order to test theories in that region. In the present study, the authors investigate the ionization of praseodymium ions, where cross section data has not been available up to now

[en] Electron-impact ionization cross sections σ_q,q+n have been measured for the reaction e + Sm^q+ → Sm^(q+n) + (n + 1)e for single, double and triple ionization and initial charge states q = 1, 2, 3. The measurements have been performed using the dynamic crossed-beams technique in an energy range from the respective ionization threshold up to 1 keV. Furthermore, we have measured the single-ionization cross section for Sm¹²⁺ using the dynamic crossed- beams method and an energy-scan method. The cross sections are compared with semi-empirical formulae. In most cases the measured cross sections are described insufficiently. In the single-ionization cross section for Sm¹²⁺ a remarkable number of narrow structures resulting from resonant excitation with subsequent double-autoionization (REDA) are observed. (orig.)

[en] Using the dynamic crossed-beams method, the following absolute cross sections σ_q,q+n for single (n=1), double (n=2) and triple (n=3) ionization by electron impact have been measured for the reaction e^-+Pr^q+→Pr^(q+n)++(n+1)e^- n=1: σ_2,3 σ_3,4σ_4,5 σ_6,7 σ_7,8 σ_8,9 σ_11,12 n=2: σ_1,3 σ_2,4 σ_3,5 σ_4,6 n=3: σ_1,4 σ_2,5 σ_3,6 The measurements have been performed in an energy range from the respective threshold up to 1 keV. For the single-ionization cross sections, contributions from excitation-autoionization processes increase with increasing charge state of the parent ion. As no theoretical calculations on praseodymium ions exist, these cross sections are compared to the semi-empirical Lotz formula [Zeitschrift fuer Physik 232 (1970) 101]. Where contributions of indirect inner-shell processes to the cross section are expected, we conducted energy-scan measurements with high energy resolution. For multiple ionization, no theoretical calculations on praseodymium ions exist. Therefore, the measured cross sections were compared to the semi-empirical formulae by Belenger et al. [J. Phys. B: At. Mol. Opt. Phys. 30 (1997) 2667] and Fisher et al. [J. Phys. B: At. Mol. Opt. Phys. 28 (1995) 3027]

[en] Conventional production of uranium across the world creates millions of tonnes of tailings annually, which are typically placed in above ground tailings impoundments. However, particularly tailings resulting from leaching of high grade uranium ores have the potential to cause serious environmental impacts. In spite of significant improvements which have been made in recent years to operational and short term safety of those tailings impoundments, their provision of reliable long term safety is still not satisfying. By advancement of the processing technology for uranium ore a solution is achieved to comprehensively eliminate risks which can derive from those tailings. Removal of radionuclides other than uranium as well as toxic metals can be achieved, if also these are intentionally extracted. The overall objective is to prevent the generation of future uranium production legacies with associated high follow–up costs. (author)

[en] Electron impact ionization cross sections σ_q,q+n for gallium ions have been measured for the reaction e + Ga^q+ → Ga^(q+n)+ + (n + 1)e for single (n = 1, q = 1, 3, 8) and triple (n = 3, q = 3, 4) ionization. The measurements have been performed using the crossed-beams technique in an energy range from the respective ionization threshold up to 1 keV, partly up to 6 keV. The cross sections for single ionization of ions in the charge state q = 1 and 3 show contributions below the ground state threshold caused by ionization of ions in excited, long-lived states in the parent ion beam. The cross sections are compared with the semiempirical Lotz formula. The cross section for Ga⁴⁺ triple ionization shows contributions from inner-shell processes. Semiempirical formulae are in good agreement with the experimental data only at energies below the cross section maximum. (orig.)

[en] Absolute cross sections σ_q,q+n for the multiple ionization of C^q+, N^q+ and O^q+ ions were measured for the reactions: e + A^q+ → A^(q+n)+ + (n + 1)e. The measurements were performed for electron energies up to 6.5 keV using the animated crossed-beams method at the Giessen electron-ion crossed-beams set-up. K-shell ionization with subsequent autoionization or even double-autoionization strongly contributes to the cross sections. (orig.)

[en] Short communication