Project IPAD; A Database to catalogue the analysis of Fukushima Daiichi accident fragmental release material

Martin, P.*; Alhaddad, O.*; Verbelen, Y.*; Satou, Yukihiko; Igarashi, Yasuhito*; Scott, T. B.*

Scientific Data (Internet), 7, p.282_1 - 282_8, 2020/08

https://doi.org/10.1038/s41597-020-00626-8

Compositional and structural analysis of Fukushima-derived particulates using high-resolution X-ray imaging and synchrotron characterisation techniques

Martin, P. G.*; Jones, C. P.*; Cipiccia, S.*; Batey, D. J.*; Hallam, K. R.*; Satou, Yukihiko; Griffiths, I.*; Rau, C.*; Richards, D. A.*; Sueki, Keisuke*; et al.

Scientific Reports (Internet), 10(1), p.1636_1 - 1636_11, 2020/01

https://doi.org/10.1038/s41598-020-58545-y

Provenance of uranium particulate contained within Fukushima Daiichi Nuclear Power Plant Unit 1 ejecta material

Martin, P. G.*; Louvel, M.*; Cipiccia, S.*; Jones, C. P.*; Batey, D. J.*; Hallam, K. R.*; Yang, I. A. X.*; Satou, Yukihiko; Rau, C.*; Mosselmans, J. F. W.*; et al.

Nature Communications (Internet), 10, p.2801_1 - 2801_7, 2019/06

https://doi.org/10.1038/s41467-019-10937-z

Synchrotron radiation (SR) analysis techniques alongside secondary ion mass spectrometry (SIMS) measurements have been made on sub-mm particulate material derived from reactor Unit 1 of the Fukushima Daiichi Nuclear Power Plant (FDNPP). Using these methods, it has been possible to investigate the distribution, state and isotopic composition of micron-scale U particulate contained within the larger Si-based ejecta material. Through combined SR micro-focused X-ray fluorescence (SR-micro-XRF) and absorption contrast SR micro-focused X-ray tomography (SR-micro-XRT), the U particulate was found to be located around the exterior circumference of the highly-porous particle. Synchrotron radiation micro-focused X-ray absorption near edge structure (SR-micro-XANES) analysis of a number of these entrapped particles revealed them to exist within the U(IV) oxidation state, as UO, and identical in structure to reactor fuel. Confirmation that this U was of nuclear origin (U-enriched) was provided through secondary ion mass spectrometry (SIMS) analysis with an isotopic enrichment ratio characteristic of a provenance from reactor Unit 1 at the FDNPP. These results provide clear evidence of the event scenario (that a degree of core fragmentation and release occurred from reactor Unit 1), with such spent fuel ejecta existing; (i) within the stable U(IV) oxidation state; and (ii) contained within a bulk Si-based particle. While this U is unlikely to represent an environmental or health hazard, such assertions would likely change, however, should break-up of the Si-containing bulk particle occur. However, more important to the long-term decommissioning of the reactors (and clean-up) on the FDNPP, is the knowledge that core integrity of reactor Unit 1 was compromised with nuclear material existing outside of the reactors primary containment.

Gyrokinetic studies of turbulence, equilibrium, and flows in the tokamak edge

Scott, B. D.*; Da Silva, F.*; Kendl, A.*; Miyato, Naoaki; Ribeiro, T.*

Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2010/html/node342.htm#70341

We report on developments in the theory and computation of gyrokinetic turbulence in the tokamak edge. A new formulation of the gyrokinetic Lagrangian for the strong EB-flow regime is been found, with clear correspondence to previous forms and to reduced MHD. Conservation of energy, mo-mentum, entropy, and particles is demonstrated at both theoretical and computational level. Neoclassical phenomena and MHD equilibration are shown in our electromagnetic total-f phase-space computational model FEFI. Delta-f gyrokinetic edge turbulence is computed on the full flux surface with the local fluxtube model delta-FEFI and results on the edge/core transition are given. We also present ongoing gyrofluid studies of ELM crash scenarios, including the influence of the bootstrap current in an edge pedestal model on both the initial instability and the resulting turbulence.

Spectroscopy of Rf

Qian, J.*; Heinz, A.*; Khoo, T. L.*; Janssens, R. V. F.*; Peterson, D.*; Seweryniak, D.*; Ahmad, I.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; et al.

Physical Review C, 79(6), p.064319_1 - 064319_13, 2009/06

https://doi.org/10.1103/PhysRevC.79.064319

-, -, and conversion electron spectroscopy experiments for Rf have been performed using Fragment Mass Analyzer at Argonne National Laboratory. A new isomer with a half-life of 160 s has been discovered in Rf, and it is interpreted as a three-quasiparticle high- isomer. Neutron configurations of one-quasiparticle states in No, the -decay daughter of Rf, have been assigned on the basis of -decay hindrance factors. Excitation energies of the 1/2[620] states in =151 isotones indicate that the deformed shell gap at =152 increases with the atomic number.

Uncategorized radioactive particles isolated from southwest region from the Fukushima Dai-ichi Nuclear Power Station

Satou, Yukihiko; Sueki, Keisuke*; Ishii, Tatsuya*; Igarashi, Junya*; Martin, P.*; Jones, C.*; Scott, T.*

no journal, , 

In Fukushima accident, insoluble radioactive Cs particles found at the northwestern region from the Fukushima Dai-ichi Nuclear Power Station (1FNPS). Presence of Cs particle in other surrounding area from 1FNPS is unclear yet. In the present study, the presence of other particle emission events and the presence of new types of radioactive particles were investigated by expanding the search object to soil samples collected outside the 1FNPS northwest region where insoluble Cs particles were reported. Four radioactive particles found from the samples. The particles look like pebbles and diameter is 0.4 to 2 mm, and the size feature is Type B. Isotopic ratio of Cs is very similar to type A of 1.0. EDS results confirmed the presence of iron and aluminum in addition to silicon. Further, in the CT image, there was an absorption point near the surface indicating that the element is heavier than iron. Although these features are clearly different from the insoluble Cs particles that have been reported in the past, in this implementation item it is not possible to find the location where Cs is adsorbed, and further direct emission from uranium or in the reactor.

Development of sample data library for radioactive particle

Satou, Yukihiko; Igarashi, Yasuhito*; Martin, P.*; Alhaddad, O.*; Scott, T.*

no journal, , 

no abstracts in English