Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Po retention factors for cooking, decay loss and maricultureJohansen, M. P.*; Carpenter, J. G.*; Charmasson, S.*; Gwynn, J. P.*; McGinnity, P.*; 森 愛理; Orr, B.*; Simon-Cornu, M.*; Osvath, I.*
Journal of Environmental Radioactivity, 268-269, p.107243_1 - 107243_10, 2023/11
被引用回数：1 パーセンタイル：0(Environmental Sciences)Po has been identified as one of the main contributors to ingestion doses to humans, particularly from the consumption of seafood. The amount of Po activity concentration data for various types of seafood has increased greatly in recent times. However, to provide realistic seafood dose assessments, most Po data requires correction to account for losses that can occur before the seafood is actually consumed. We develop generic correction factors for the main processes associated with reduction of Po in seafood - leaching during cooking, radioactive decay between harvest and consumption, and sourcing from mariculture versus wild-caught. When seafood is cooked, the overall mean fraction of Po retained is 0.74 for all cooking and seafood types, with the means for various seafoods and cooking categories ranging from 0.56 to 1.03. When considering radioactive decay between harvest and consumption, the overall mean fraction remaining is 0.81 across all seafood preservation/packaging types, with estimates ranging from 0.50 (canned seafood) to 0.98 (fresh seafood). Regarding mariculture influence, the available limited data suggest marine fish and crustaceans raised with processed feed have about one order of magnitude lower Po muscle content than wild-caught seafood of the same or similar species, although this ratio varies. Overall, this study concludes that Po activity concentrations in seafood at the time of ingestion may be reduced to only about 55% compared to when it was harvested. Therefore, correction factors must be applied to any data derived from environmental monitoring in order to achieve realistic dose estimates. The data also suggest lower Po ingestion doses for consumers who routinely favour cooked, long shelf-life and farmed fish/crustaceans. However, more data is needed in some categories, especially for cooking of molluscs and seaweed, and for the Po content in all farmed seafood.
Johansen, M. P.*; Child, D. P.*; Collins, R.*; Cook, M.*; Davis, J.*; Hotchkis, M. A. C.*; Howard, D. L.*; Howell, N.*; 池田 篤史; Young, E.*
Science of the Total Environment, 842, p.156755_1 - 156755_11, 2022/10
被引用回数：4 パーセンタイル：53.82(Environmental Sciences)While they have appeared only recently in earth's history, radioactive particles from anthropogenic sources are widespread in global environments and present radiological harm potentials to living organisms. Here we compare a varied set of particles from past nuclear fission and non-fission sources in Australia of highly diverse magnitudes, release modes, and environments. Numerous radioactive particles persist in soils 60 + years after their release events. Particles can be distinguished by their Ca/Fe and Si/Fe elemental ratios, which in this study range over orders of magnitude and reflect the materials available during their individual formation events. The particles from nuclear testing have dominant 
Pu activity concentrations, relative to 
Sr and 
Cs, which increases long-term radiological hazard from alpha emissions if inhaled or ingested, and contrasts with particles from nuclear power accidents (e.g., Fukushima). Internal fracturing is more prevalent than previously reported, and fracturing is greater in Ca-rich vs. Si-dominated matrices.
Ar by the (
) two-neutron transfer reactionNowak, K.*; Wimmer, K.*; Hellgartner, S.*; M
cher, D.*; Bildstein, V.*; Diriken, J.*; Elseviers, J.*; Gaffney, L. P.*; Gernh
user, R.*; Iwanicki, J.*; et al.
Physical Review C, 93(4), p.044335_1 - 044335_10, 2016/04
被引用回数：18 パーセンタイル：77.39(Physics, Nuclear)The 
Ar()Ar two-neutron transfer reaction at 2.16 MeV/u was studied at CERN using a Ar radioactive beam and a tritium loaded radioactive target. Angular distributions for three final states were measured and based on the shape of the differential cross section an excited state at 3695 keV was identified as the first excited 0
state. The differential cross-sections for the 0
-ground state, and first excited 2 and 0 states are compared to DWBA calculations including two-step reactions through the intermediate nucleus 
Ar. By comparison large scale shell model calculations using state-of-the-art effective interactions, with and without the tensor components of the interactions, it was observed that the cross-shell proton-neutron tensor interaction has measurable effects on the observables at low excitation energy in Ar.
Ni; Spectroscopy of the N=49 isotope 
ZnOrlandi, R.; Mcher, D.*; Raabe, R.*; Jungclaus, A.*; Pain, S. D.*; Bildstein, V.*; Chapman, R.*; De Angelis, G.*; Johansen, J. G.*; Van Duppen, P.*; et al.
Physics Letters B, 740, p.298 - 302, 2015/01
被引用回数：29 パーセンタイル：85.36(Astronomy & Astrophysics)Single-neutron states in Zn have been populated using the reaction Zn(d,p) at REX-Isolde, CERN. The analysis reveals that the lowest excited states in Zn lie at approximately 1 MeV, and involve neutron orbits above the N=50 shell gap. A 5/2
configuration was assigned to the 983-keV state. Comparison with large-scale shell model calculations supports a robust neutron N=50 shell closure for Ni. These data constitute an important step towards the understanding the magicity of Ni and the structure of nuclei in the region.
Zn and the structure of NiOrlandi, R.; Mcher, D.*; Raabe, R.*; Jungclaus, A.*; Pain, S. D.*; Bildstein, V.*; Chapman, R.*; De Angelis, G.*; Johansen, J. G.*; Van Duppen, P.*; et al.
no journal, ,
Single-neutron states in the 
= 49 isotope Zn were populated in the Zn(d,p)Zn transfer reaction at REX-ISOLDE, CERN. The combined detection of protons ejected in the reaction and of 
rays emitted by Zn permitted the identification of the lowest-lying 5/2 and 1/2 excited states. The analysis of proton angular distributions links these states to a significant amount of single-particle strength around 1 MeV, and specifically to the 
d
and s
neutron orbits, which lie above the = 50 neutron shell gap. Comparison with large-scale-shell-model calculations supports a robust = 50 shell-closure for Ni. These data constitute a considerable step towards the understanding of the magicity of Ni and of the structure of isotopes in the region.
森 愛理; Johansen, M. P.*; 高原 省五
no journal, ,
Radionuclides released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) spread into the environment by various pathways, including the marine ecosystem and eventually into some marine organisms that could be consumed as seafood. Assessing this pathway is important from the perspective of public radiation protection. The ICRP presents two assessment methods (probabilistic and deterministic methods) for determining the dose for persons who are exposed to radiation. Which method to use and which specific values to select for each method depends on the characteristics of the assessment and available data, and it is left to the interpretation of the assessors. In this study, internal dose from seafood ingestion was assessed using an extensive compilation of activity concentrations in seafood that considers 22 radionuclides. The assessment receptor represents the residents in the Tohoku region which includes the Fukushima Prefecture. Representative consumption rates were obtained from a national nutritional survey. From the probabilistic calculation, the 95th percentile dose from the FDNPP accident-derived radionuclides was 22 
Sv from seafood consumption during the first year after the accident and 1.6 Sv during the second and third year. Overall, the ingestion dose for typical seafood consumers of the Tohoku region returned to near background levels within 3 years. The differences in results between probabilistic and deterministic methods will be discussed in the presentation.
Johansen, M. P.*; Carpenter, J. G.*; Charmasson, S.*; Gwynn, J. P.*; McGinnity, P.*; 森 愛理; Orr, B.*; Simon-Cornu, M.*; Osvath, I.*
no journal, ,
Artificial and natural radionuclides are known to accumulate in seafood worldwide and cause internal dose to seafood consumers. It has been nearly 30 years since the IAEA MARDOS global seafood dose assessment was published. Since then, world seafood consumption has increased, diet patterns have changed, and new inputs of radionuclides into marine systems have occurred. A new global assessment of seafood dose is being conducted that uses a much-expanded global database on radionuclides in seafood (Marine Radioactivity Information System -MARIS) as well as global diet data and updated parameters for dose calculation. The new assessment: (i) Evaluates 16 natural and anthropogenic radionuclides. (ii) Draws from more than 84,856 global data for biota in MARIS, from which 31,665 final activity concentration data passed quality assurance screening. (iii) Uses seafood consumption data from diet studies representing approximately 35% of the world population. (iv) Develops new correction factors for the loss of Po-210 from cooking and radiological decay as well as the decreases in Po-210 in maricultured seafood. (v) Implements a bespoke Monte Carlo application for calculating seafood dose distributions. (vi) Compiles and evaluates + 150 seafood ingestion dose estimates published in the past 30 years. The results provide well-supported estimates on the mean and distribution of background seafood dose for world consumers. This important new result provides a comparative reference for local, regional and national dose assessments; for the dose rates resulting from facility and accident releases, and for quantifying the global changes in ingestion dose from seafood over time. The assessment is being conducted within the IAEA Coordinated Research Project "Behaviour and Effects of Natural and Anthropogenic Radionuclides in the Marine Environment and their Use as Tracers for Oceanography Studies."
