Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 36

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Structural and compositional characteristics of Fukushima release particulate material from Units 1 and 3 elucidates release mechanisms, accident chronology and future decommissioning strategy

Martin, P. G.*; Jones, C. P.*; Bartlett, S.*; Ignatyev, K.*; Megson-Smith, D.*; Satou, Yukihiko; Cipiccia, S.*; Batey, D. J.*; Rau, C.*; Sueki, Keisuke*; et al.

Scientific Reports (Internet), 10, p.22056_1 - 22056_17, 2020/12

 Times Cited Count:0 Percentile:0.01(Multidisciplinary Sciences)

Journal Articles

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

 Times Cited Count:5 Percentile:50.12(Multidisciplinary Sciences)

Journal Articles

Nuclear data sheets for A=218

Singh, B.*; Basunia, M. S.*; Martin, M.*; McCutchan, E. A.*; Bara, I.*; Caballero-Folch, R.*; Canavan, R.*; Chakrabarti, R.*; Chekhovska, A.*; Grinder, M. M.*; et al.

Nuclear Data Sheets, 160, p.405 - 471, 2019/09

 Times Cited Count:5 Percentile:61.87(Physics, Nuclear)

Journal Articles

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(1), p.2801_1 - 2801_7, 2019/06

 Times Cited Count:20 Percentile:84.61(Multidisciplinary Sciences)

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$$_{2}$$, and identical in structure to reactor fuel. Confirmation that this U was of nuclear origin ($$^{235}$$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.

Journal Articles

Effects of fine-scale surface alterations on tracer retention in a fractured crystalline rock from the Grimsel Test Site

Tachi, Yukio; Ito, Tsuyoshi*; Akagi, Yosuke*; Sato, Hisao*; Martin, A. J.*

Water Resources Research, 54(11), p.9287 - 9305, 2018/11

 Times Cited Count:5 Percentile:38.47(Environmental Sciences)

Effects of fine-scale surface alterations on radionuclide migration in fractured crystalline rocks were investigated by a comprehensive approach coupling a series of laboratory tests, microscopic observations and modelling, using a single fractured granodiorite sample from the Grimsel Test Site, Switzerland. Laboratory tests including through-diffusion, batch sorption and flow-through tests using five tracers indicated that tracer retention was consistently in the sequence of HDO, Se, Cs, Ni, Eu, and as well as showing the existence of a diffusion-resistance layer near the fracture surface, cation excess and anion exclusion effects for diffusion. Microscale heterogeneities in structural properties around the fracture were clarified quantitatively by coupling X-ray CT and EPMA. A three layer model including weathered vermiculite, foliated mica and undisturbed matrix layers, and their properties such as porosity, sorption and diffusion parameters, could provide a reasonable interpretation for breakthrough curves and concentration distributions near fracture surface of all tracers, measured in flow-through tests.

Journal Articles

OECD/NEA benchmark on pellet-clad mechanical interaction modelling with fuel performance codes; Impact of number of radial pellet cracks and pellet-clad friction coefficient

Dost$'a$l, M.*; Rossiter, G.*; Dethioux, A.*; Zhang, J.*; Amaya, Masaki; Rozzia, D.*; Williamson, R.*; Kozlowski, T.*; Hill, I.*; Martin, J.-F.*

Proceedings of Annual Topical Meeting on Reactor Fuel Performance (TopFuel 2018) (Internet), 10 Pages, 2018/10

Journal Articles

Super-absorbent polymer valves and colorimetric chemistries for time-sequenced discrete sampling and chloride analysis of sweat via skin-mounted soft microfluidics

Kim, S. B.*; Zhang, Y.*; Won, S. M.*; Bandodkar, A. J.*; Sekine, Yurina; Xue, Y.*; Koo, J.*; Harshman, S. W.*; Martin, J. A.*; Park, J. M.*; et al.

Small, 14(12), p.1703334_1 - 1703334_11, 2018/03

 Times Cited Count:63 Percentile:94.96(Chemistry, Multidisciplinary)

Journal Articles

The Martian surface radiation environment; A Comparison of models and MSL/RAD measurements

Matthi$"a$, D.*; Ehresmann, B.*; Lohf, H.*; K$"o$hler, J.*; Zeitlin, C.*; Appel, J.*; Sato, Tatsuhiko; Slaba, T. C.*; Martin, C.*; Berger, T.*; et al.

Journal of Space Weather and Space Climate (Internet), 6, p.A13_1 - A13_17, 2016/03

 Times Cited Count:55 Percentile:95.1(Astronomy & Astrophysics)

The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) has been measuring the radiation environment on the surface of Mars since August 6th 2012. In this work, several models such as GEANT4, PHITS, and HZETRN/OLTARIS are used to predict the radiation environment caused by galactic cosmic rays on Mars in order to compare and validate them with the experimental results. Although good agreement is found in many cases for GEANT4, PHITS and HZETRN/OLTARIS, some models still show large, sometimes order of magnitude, discrepancies in certain particle spectra. We have found that RAD data is helping make better choices of input parameters and physical models. These results help to predict dose rates for future manned missions as well as to perform shield optimization studies.

Journal Articles

Matrix diffusion and sorption of Cs$$^{+}$$, Na$$^{+}$$, I$$^{-}$$ and HTO in granodiorite; Laboratory-scale results and their extrapolation to the in situ condition

Tachi, Yukio; Ebina, Takanori*; Takeda, Chizuko*; Saito, Toshihiko*; Takahashi, Hiroaki*; Ouchi, Yuji*; Martin, A. J.*

Journal of Contaminant Hydrology, 179, p.10 - 24, 2015/08

 Times Cited Count:27 Percentile:78.93(Environmental Sciences)

Matrix diffusion and sorption are important processes in the assessment of radionuclide transport in crystalline rocks. Diffusion and sorption parameters for Cs$$^{+}$$, Na$$^{+}$$, I$$^{-}$$ and HTO were determined by through-diffusion and batch sorption experiments using granodiorite samples from the Grimsel Test Site, Switzerland. The De values were in the order Cs$$^{+}$$, Na$$^{+}$$, HTO, I$$^{-}$$. The capacity factor and Kd values show the same trends. The dual depth profiles for Cs$$^{+}$$ and Na$$^{+}$$ can be interpreted by a near-surface Kd increment. The microscopic analysis indicated that this is caused by high porosity and sorption capacities in disturbed biotite minerals on the sample surface. The Kd values derived from the dual profiles are likely to correspond to Kd dependence on the grain sizes of crushed samples in the batch experiments. The results of the in situ LTD experiments were interpreted reasonably well by using transport parameters derived from laboratory data and extrapolating them to in situ conditions.

Journal Articles

Comparative modeling of an in situ diffusion experiment in granite at the Grimsel Test Site

Soler, J. M.*; Landa, J.*; Havlov$'a$, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Eikenberg, J.*; Martin, A. J.*

Journal of Contaminant Hydrology, 179, p.89 - 101, 2015/08

 Times Cited Count:33 Percentile:84.06(Environmental Sciences)

Matrix diffusion is a key process for radionuclide retention in crystalline rocks. An in-situ diffusion experiment in granite matrix was performed at the Grimsel Test Site (Switzerland). Several tracers (HTO, Na$$^{+}$$, Cs$$^{+}$$) were circulated through a borehole and the decrease in tracer concentrations was monitored for 2.5 years. Then, the borehole section was overcored and the tracer profiles in the rock were analyzed. Transport distances in the rock were 20 cm for HTO, 10 cm for Na$$^{+}$$ and 1 cm for Cs$$^{+}$$. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusivities (De) and rock capacity factors. There was a rather good agreement between the values from different teams, implied that De and capacity factors in the borehole damaged zone are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results.

Journal Articles

Modeling of an in-situ diffusion experiment in granite at the Grimsel Test Site

Soler, J. M.*; Landa, J.*; Havlov$'a$, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Martin, A. J.*

Materials Research Society Symposium Proceedings, Vol.1665, p.85 - 91, 2014/09

Matrix diffusion is a key process for radionuclide retention in crystalline rocks. An in-situ diffusion experiment in granite matrix was performed at the Grimsel Test Site (Switzerland). Several tracers (HTO, Na$$^{+}$$, Cs$$^{+}$$) were circulated through a borehole and the decrease in tracer concentrations was monitored for 2.5 years. Then, the borehole section was overcored and the tracer profiles in the rock were analyzed. Transport distances in the rock were 20 cm for HTO, 10 cm for Na$$^{+}$$ and 1 cm for Cs$$^{+}$$. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusivities ($$D$$e) and rock capacity factors. There was a rather good agreement between the values from different teams, implied that $$D$$e and capacity factors in the borehole damaged zone are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results, which have to be investigated in more detail.

Journal Articles

LTD experiment; Postmortem modelling of monopole I

Soler, J. M.*; Landa, J.*; Havlov$'a$, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Martin, A.*

Nagra NAB 12-53, 80 Pages, 2013/02

An in-situ long-term diffusion (LTD) experiment was performed at the Grimsel Test Site (Switzerland). Tracers, HTO, $$^{22}$$Na$$^{+}$$, $$^{134}$$Cs$$^{+}$$, were continuously circulated through a packed-off borehole and the tracer concentrations in the solution was monitored for 2.5 years. Subsequently, the borehole section was overcored and the tracer profiles in the rock analyzed. The drop in activity for Cs$$^{+}$$ in the solution was much pronounced. Transport distances were about 20 cm for HTO, 10 cm for Na$$^{+}$$ and 1 cm for Cs$$^{+}$$. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusion coefficients ($$D$$$$_{e}$$) and rock capacity ($$alpha$$) values. There was a rather good agreement between the values from different teams, implied that $$D$$$$_{e}$$ and $$alpha$$ values in the BDZ are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results, which have to be investigated in more detail.

Journal Articles

Application of the Bayesian approach to incorporate helium isotope ratios in long-term probabilistic volcanic hazard assessments in Tohoku, Japan

Martin, A. J.*; Umeda, Koji; Ishimaru, Tsuneari

Updates in Volcanology; New Advances in Understanding Volcanic Systems (Internet), p.119 - 148, 2012/09

The probabilistic approach can be developed with quite high levels of confidence and take into account extreme volcanic events. However, for regions with few or no volcanoes, there is a need to include additional geological, geophysical and/or geochemical data sets that may indicate the likelihood of future volcanism. This has been achieved using Bayesian inference in order to combine one or more sets of chemical or geophysical information to a priori assumptions of volcano spatio-temporal distributions yielding modified a posteriori probabilities.

Journal Articles

Overview of high priority ITER diagnostic systems status

Walsh, M.*; Andrew, P.*; Barnsley, R.*; Bertalot, L.*; Boivin, R.*; Bora, D.*; Bouhamou, R.*; Ciattaglia, S.*; Costley, A. E.*; Counsell, G.*; et al.

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

Journal Articles

Defining the infrared systems for ITER

Reichle, R.*; Andrew, P.*; Counsell, G.*; Drevon, J.-M.*; Encheva, A.*; Janeschitz, G.*; Johnson, D. W.*; Kusama, Yoshinori; Levesy, B.*; Martin, A.*; et al.

Review of Scientific Instruments, 81(10), p.10E135_1 - 10E135_5, 2010/10

 Times Cited Count:24 Percentile:71.58(Instruments & Instrumentation)

JAEA Reports

Development of safety assessment method under uncertainty for Horonobe URL project (Contract research)

Takase, Hiroyasu*; Inagaki, Manabu*; Noguchi, Toshihide*; Shimaoka, Akiko*; Martin, A. J.*; Wakamatsu, Hisanori*; Takase, Kyoko*; Tabara, Michiko*; Matsui, Hiroya

JAEA-Research 2007-066, 215 Pages, 2007/08

JAEA-Research-2007-066-01.pdf:43.05MB
JAEA-Research-2007-066-02.pdf:58.73MB
JAEA-Research-2007-066-03.pdf:13.08MB

In this study a systematic approach to explicitly address type and size of uncertainties associated with safety assessment due mainly to incomplete knowledge on a spatially heterogeneous geological environment was developed. In this approach a wide range of model variations including the ones with relatively law plausibility are taken into account so that ambiguity remaining in the knowledge is illustrated, which is a distinctive feature of the approach compared with the conventional methodology where only a limited number of best plausible model variations are considered. The study also proposed an approach to assessing plausibility of each model variation based on multiple pieces of evidence by using evidential support logic (ESL). Furthermore the approach was applied to Horonobe area to demonstrate its applicability to the similar class of geological environment as an example.

Journal Articles

X-ray spectroscopic diagnostics of ultrashort laser-cluster interaction at the stage of the nonadiabatic scattering of clusters

Faenov, A. Y.; Magunov, A. I.*; Pikuz, T. A.*; Skobelev, I. Y.*; Giulietti, D.*; Betti, S.*; Galimberti, M.*; Gamucci, A.*; Giulietti, A.*; Gizzi, L. A.*; et al.

JETP Letters, 86(3), p.178 - 183, 2007/08

 Times Cited Count:5 Percentile:38.32(Physics, Multidisciplinary)

Journal Articles

Progress in the ITER physics basis, 2; Plasma confinement and transport

Doyle, E. J.*; Houlberg, W. A.*; Kamada, Yutaka; Mukhovatov, V.*; Osborne, T. H.*; Polevoi, A.*; Bateman, G.*; Connor, J. W.*; Cordey, J. G.*; Fujita, Takaaki; et al.

Nuclear Fusion, 47(6), p.S18 - S127, 2007/06

no abstracts in English

Journal Articles

Recent progress on the development and analysis of the ITPA global H-mode confinement database

McDonald, D. C.*; Cordey, J. G.*; Thomsen, K.*; Kardaun, O. J. W. F.*; Snipes, J. A.*; Greenwald, M.*; Sugiyama, L.*; Ryter, F.*; Kus, A.*; Stober, J.*; et al.

Nuclear Fusion, 47(3), p.147 - 174, 2007/03

 Times Cited Count:46 Percentile:29.82(Physics, Fluids & Plasmas)

This paper describes the updates to and analysis of the International Tokamak Physics Activity (ITPA) Global H-node Confinement Database version 3 (DB3) over the period 1994-2004. Global data, for the energy confinement time and its controlling parameters, have now been collected from 18 machines of different sizes and shapes: ASDEX, ASDEX Upgrade, C-Mod CoMPASS-D, DIII-D, JET, JFT-2M, JT-60U, MAST, NSTX, PBX-M, PDX, START, T-10, TCV, TdeV, TFTR and TUMAN-3M. A wide range of physics studies has been performed on DB3 with particular progress made in the separation of core and edge behavior, dimensionless parameter analyses and the comparison of the database with one-dimensional transport code. A key aim of the database has always been to provide a basis for estimating the energy confinement properties of next step machines such as ITER, and so the impact of the database and its analysis on such machines is also discussed.

Journal Articles

Demonstrating feasible disposable concepts for long half-life, low heat generating radioactive wastes in Japan; An overview of project TRU-2

Martin, A. J.*; Kamei, Gento; Shiotsuki, Masao; Kuroda, Shigeki*

Proceedings of International Waste Management Symposium 2007 (WM '07) (CD-ROM), 12 Pages, 2007/03

In Japan, the Federation of Electric Power Companies and The Japan Atomic Energy Agency have been collaborating with relevant organizations to promote generic R&D for the safe geological disposal of TRU waste based on the technical achievements in Japan's HLW disposal program. A result of this collaborative effort was production of a recent progress report on the R&D for TRU waste disposal in Japan (project TRU-2). This paper is an overview of TRU-2 describing the key results and some unique methodologies developed.

36 (Records 1-20 displayed on this page)