Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Quach, N. M.*; Ngo, M. C.*; Yang, Y.*; Nguyen, T. B.*; Nguyen, V. T.*; Fujita, Yoshitaka; Do, T. M. D.*; Nakayama, Tadachika*; Suzuki, Tatsuya*; Suematsu, Hisayuki*
Journal of Radioanalytical and Nuclear Chemistry, 332(10), p.4057 - 4064, 2023/10
Times Cited Count:4 Percentile:71.02(Chemistry, Analytical)Technetium-99m (Tc) is the most widely used medical radioisotope in the world and is produced from molybdenum-99 (
Mo). Production of
Mo via the neutron capture method draws attention as an alternative to fission-derived
Mo due to non-proliferation issues, but the specific radioactivity of
Mo is extremely low. In this work, a porous
-MoO
wire was prepared as an irradiation target in order to improve the specific activity by extracting
Mo. Porous
-MoO
wire is synthesized from Mo metal wire by a two-step heating procedure. The hot atom effect of
Mo was confirmed by activity and isotope measurements of the porous
-MoO
wire after neutron irradiation and the water used for extraction. In term of the extraction effectiveness, the effectiveness of
Mo extraction in the porous
-MoO
wire was comparable to that of commercial
-MoO
powder.
Ngo, M. C.*; Fujita, Yoshitaka; Suzuki, Tatsuya*; Do, T. M. D.*; Seki, Misaki; Nakayama, Tadachika*; Niihara, Koichi*; Suematsu, Hisayuki*
Inorganic Chemistry, 62(32), p.13140 - 13147, 2023/08
Times Cited Count:5 Percentile:60.95(Chemistry, Inorganic & Nuclear)Technetium-99m (Tc) is one of the most important radioisotopes for diagnostic radio-imaging applications.
Tc is a daughter product of the
Mo isotope. There are two methods used to produce
Mo/
Tc: the nuclear fission (n,f) and the neutron capture (n,
) methods. Between them, the (n,f) method is the main route, used for approximately 90% of the world's production. However, the (n,f) method faces numerous problems, including the use of highly enriched uranium, the release of highly radioactive waste, and nonproliferation problems. Therefore, the (n,
) method is being developed as a future replacement for the (n,f) method. In this work,
-MoO
whiskers prepared by the thermal evaporation method and
-MoO
particles were irradiated in a nuclear reactor to produce
Mo/
Tc via neutron capture. The irradiated targets were dispersed into water to extract the
Mo/
Tc. As a result,
-MoO
whisker yielded higher
Mo extraction rate than that from
-MoO
. In addition, by comparing the dissolved
Mo concentrations in water, we clarified a prominent hot-atom of
-MoO
whiskers. This research is the first demonstration of
-MoO
being used as an irradiation target in the neutron capture method. On the basis of the results,
-MoO
is considered a promising irradiation target for producing
Mo/
Tc by neutron capture and using water for the radioisotope extraction process in the future.
Fujita, Yoshitaka; Seki, Misaki; Ngo, M. C.*; Do, T. M. D.*; Hu, X.*; Yang, Y.*; Takeuchi, Tomoaki; Nakano, Hiroko; Fujihara, Yasuyuki*; Yoshinaga, Hisao*; et al.
KURNS Progress Report 2021, P. 118, 2022/07
no abstracts in English
Burr, T.*; Suzuki, Mitsutoshi; Howell, J.*; Jongo, C. E.*; Hamada, M. S.*
Nuclear Instruments and Methods in Physics Research A, 640(1), p.200 - 212, 2011/06
Times Cited Count:9 Percentile:54.99(Instruments & Instrumentation)Process monitoring (PM) is increasingly important in nuclear safeguards as a complement to mass-balance based nuclear materials accounting (NMA). Typically, PM involves more frequent but lower quality measurements than NMA. While NMA estimates special nuclear material (SNM) mass balances and uncertainties, PM often tracks SNM attributes qualitatively or in the case of solution monitoring (SM) tracks bulk mass and volume. Automatic event marking is used in several nuclear safeguards PM systems. All methods are evaluated on both raw and smoothed data, and several smoothing options are compared, including standard filters, hybrid filters, and local kernel smoothing. The main finding is that for real and simulated examples considered, a two-step strategy is most effective. First, any reasonably effective initial smoother is used to provide a good initial guess at change point locations. Second, PLR is applied, looking for one change point at a time.
Kanungo, R.*; Nociforo, C.*; Prochazka, A.*; Utsuno, Yutaka; Aumann, T.*; Boutin, D.*; Cortina-Gil, D.*; Davids, B.*; Diakaki, M.*; Farinon, F.*; et al.
Physics Letters B, 685(4-5), p.253 - 257, 2010/05
Times Cited Count:37 Percentile:86.47(Astronomy & Astrophysics)no abstracts in English
Kanungo, R.*; Nociforo, C.*; Prochazka, A.*; Aumann, T.*; Boutin, D.*; Cortina-Gil, D.*; Davids, B.*; Diakaki, M.*; Farinon, F.*; Geissel, H.*; et al.
Physical Review Letters, 102(15), p.152501_1 - 152501_4, 2009/04
Times Cited Count:181 Percentile:96.80(Physics, Multidisciplinary)no abstracts in English
Mazzocco, M.*; Signorini, C.*; Romoli, M.*; De Francesco, A.*; Di Pietro, M.*; Vardaci, E.*; Yoshida, Koichi*; Yoshida, Atsushi*; Bonetti, R.*; De Rosa, A.*; et al.
European Physical Journal A, 28(3), p.295 - 299, 2006/06
Times Cited Count:46 Percentile:89.49(Physics, Nuclear)The scattering of the radioactive, weakly bound, halo nucleus Be from
Bi has been studied at 40 MeV. The measurement performed with a low-intensity and a large-emittance secondary beam could be made using an extremely compact, large solid angle (
2
sr) detecting set-up, based on 8 highly segmented Si telescopes. The
Be scattering angular distributions, as well as their relative reaction cross-sections, resulted to be rather similar. This may suggest that at Coulomb barrier energies the halo structure and the small weakly binding energy of the
Be projectile have no big influence on the reaction dynamics.
Suematsu, Hisayuki*; Ngo, M. C.*; Quach, N. M.*; Fujita, Yoshitaka; Do, T. M. D.*; Nakayama, Tadachika*; Suzuki, Tatsuya*; Nguyen, V. T.*; Niihara, Koichi*
no journal, ,
Radiopharmacies have been used in various medical diagnoses/therapies and their market has been growing by ten times in fifteen years. In particular, Tc has been widely used in gamma ray diagnoses.
Mo, the raw material for
Tc, is currently produced as a fission product by irradiating highly enriched uranium in nuclear reactors. Efforts are being made worldwide to reduce the use of uranium from the perspective of nuclear non-proliferation. A
Mo(n,
)
Mo reaction in low enriched uranium reactors can be an alternative method. In this research, we revealed that
-MoO
, a low-temperature phase of MoO
, as a neutron irradiation target promotes the diffusion of
Mo from the target to water due to the hot atom effect. Utilizing this phenomenon can contribute to the stable supply of
Mo and
Tc. The first nuclear reaction in/water dispersion experiments using an
-MoO
powder target was carried out in Dalat Nuclear Reactor, Vietnam Atomic Energy Institute to show the hot atom effect. Then, the water recovery efficiency was dramatically improved using a novel
-MoO
whisker target by Vietnamese students and staffs. Their contributions to this research will be explained in the presentation.
Broughton, D.*; Suzuki, Risa; Nagatani, Taketeru; Okada, Toyofumi; Henzlova, D.*; Longo, J.*; Mendez, J.*; Rael, C.*; Swinhoe, M. T.*
no journal, ,
This presentation will discuss issues and potential improvements in the measurement of nuclear material generated from ongoing decommissioning activities at JAEA facilities. This material is subject to safeguards requirements, but its high impurity content makes it difficult to measure using standard deployed NDA systems.