JOPSS - Search Results

Journal Articles

Developing accelerator mass spectrometry capabilities for anthropogenic radionuclide analysis to extend the set of oceanographic tracers

Hain, K.*; Martschini, M.*; Glce, F.*; Honda, Maki; Lachner, J.*; Kern, M.*; Pitters, J.*; Quinto, F.*; Sakaguchi, Aya*; Steier, P.*; et al.

Frontiers in Marine Science (Internet), 9, p.837515_1 - 837515_17, 2022/03

https://doi.org/10.3389/fmars.2022.837515

Times Cited Count：12 Percentile：95.34(Environmental Sciences)

Recent major advances in accelerator mass spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA) regarding detection efficiency and isobar suppression have opened possibilities for the analysis of additional long-lived radionuclides at ultra-low environmental concentrations. These radionuclides, including $^{233}$ U, $^{135}$ Cs, $^{99}$ Tc and $^{90}$ Sr, will become important for oceanographic tracer application due to their generally conservative behavior in ocean water. In particular, the isotope ratios $^{233}$ U/ $^{236}$ U and $^{137}$ Cs/ $^{135}$ Cs have proven to be powerful fingerprints for emission source identification as they are not affected by elemental fractionation. Improved detection efficiencies allowed us to analyze all major long-lived actinides, i.e. $^{236}$ U, $^{237}$ Np, $^{239, 240}$ Pu, $^{241}$ Am as well as the very rare $^{233}$ U, in the same 10 L water samples of an exemplary depth profile from the northwest Pacific Ocean. Especially for $^{90}$ Sr analysis, our new approach has already been validated for selected reference materials (e.g. IAEA-A-12) and is ready for application in oceanographic studies. We estimate that a sample volume of only (1-3) L ocean water is sufficient for $^{90}$ Sr as well as $^{135}$ Cs analysis, respectively.

Journal Articles

Development and testing of a delayed gamma-ray spectroscopy instrument utilizing Cf-252 neutrons evaluated for nuclear safeguards applications

Rodriguez, D.; Abbas, K.*; Koizumi, Mitsuo; Nonneman, S.*; Rossi, F.; Takahashi, Tone

Nuclear Instruments and Methods in Physics Research A, 1014, p.165685_1 - 165685_10, 2021/10

https://doi.org/10.1016/j.nima.2021.165685

Times Cited Count：4 Percentile：55.56(Instruments & Instrumentation)

Journal Articles

Development methodology on determination of instant release fractions for generic safety assessment for direct disposal of spent nuclear fuel

Kitamura, Akira; Akahori, Kuniaki; Nagata, Masanobu*

Genshiryoku Bakkuendo Kenkyu (CD-ROM), 27(2), p.83 - 93, 2020/12

https://doi.org/10.3327/jnuce.27.2_83

Direct disposal of spent nuclear fuel (SNF) in deep underground repositories (hereafter "direct disposal") is a concept that disposal canisters stored fuel assemblies dispose without reprocessing. Behavior of radionuclide release from SNF must be different from that from vitrified glass. The present study established a methodology on determination of instant release fraction (IRF) of radionuclides from SNF, which is the one of the parameters on radionuclide release based on the latest safety assessment reports in other countries, especially for IRF values proportional to a fission gas release ratio (FGR). Recommended and maximum values of FGR have been estimated using the fuel performance code FEMAXI-7 after collecting FGR values on Japanese SNFs. Furthermore, recommended and maximum values of IRF for Japanese SNFs used in a pressurized water reactor (PWR) have been estimated using the presently obtained FGR values and experimentally obtained IRF values on foreign SNFs. The recommended and maximum IRF values obtained in the present study have been compared with those of the latest safety assessment reports in other countries.

JAEA Reports