Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 266

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

JAEA Reports

Study on waste acceptance criteria for waste packages destined for near surface disposal containing radioactive waste from research, industrial and medical facilities; Minimization of the amounts of scattering radionuclides caused by dropping impact

Nakata, Hisakazu; Okada, Shota; Amazawa, Hiroya; Sakai, Akihiro

JAEA-Technology 2023-021, 31 Pages, 2024/01

JAEA-Technology-2023-021.pdf:2.53MB

Radioactive waste packages, which Japan Atomic Energy Agency (JAEA) plans to dispose of, must meet the technical criteria specified by the Order of Nuclear Regulation Authority. One criteria is newly specified in 2019 such that it shall be impact resistant performance so as to be few in quantity of radionuclides released from the waste package in case of dropping from the maximum height assumed in the disposal process. Then, JAEA needs to prove the compliance of the waste package with the technical criteria by estimating the leakage of radionuclides. In this report, the amounts of scattering materials inside two waste packages caused by dropping impact from 8m height was estimated by numerical analysis, providing the ratio of the amounts of scattering materials to the weight of the waste package. The analysis objects were 1m$$^{3}$$ cube container-filled and solidified waste package containing metal waste, which are expected to emplace into a vault-type disposal facility. Some considerations relating to the production method of the waste package using 1m$$^{3}$$ cubic container and its waste acceptance criteria are provided on the basis of the drop analysis in this report.

JAEA Reports

Common evaluation procedure radioactivity concentration by theoretical calculation for radioactive waste generated from the decommissioning of research reactors

Okada, Shota; Murakami, Masashi; Kochiyama, Mami; Izumo, Sari; Sakai, Akihiro

JAEA-Testing 2022-002, 66 Pages, 2022/08

JAEA-Testing-2022-002.pdf:2.46MB

Japan Atomic Energy Agency is an implementing organization of burial disposal for low-level radioactive waste generated from research, industrial and medical facilities in Japan. Radioactivity concentrations of the waste are essential information for design of the disposal facility and for licensing process. A lot of the waste subjected to the burial disposal is arising from dismantling of nuclear facilities. Radioactive Wastes Disposal enter has therefore discussed a procedure to evaluate the radioactivity concentrations by theoretical calculation for waste arising from the dismantling of the research reactors facilities and summarized the common procedure. The procedure includes evaluation of radioactive inventory by activation calculation, validation of the calculation results, and determination of the disposal classification as well as organization of the data on total radioactivity and maximum radioactivity concentration for each classification. For the evaluation of radioactive inventory, neutron flux and energy spectra are calculated at each region in the reactor facility using two- or three-dimensional neutron transport code. The activation calculation is then conducted for 140 nuclides using the results of neutron transport calculation and an activation calculation code. The recommended codes in this report for neutron transport calculation are two-dimensional discrete ordinate code DORT, three-dimensional discrete ordinate code TORT, or Monte Carlo codes MCNP and PHITS, and for activation calculation is ORIGEN-S. Other recommendation of cross-section libraries and calculation conditions are also indicated in this report. In the course of the establishment of the procedure, Radioactive Wastes Disposal Center has discussed the commonly available procedure at meetings. It has periodically held to exchange information with external operators which have research reactor facilities. The procedure will properly be reviewed and be revised by reflecting future situ

JAEA Reports

Evaluation of radioactivity concentration corresponding to dose criterion for near surface disposal of radioactive waste generated from research, medical, and industrial facilities, Volume 2

Sakuma, Kota; Abe, Daichi*; Okada, Shota; Sugaya, Toshikatsu; Nakata, Hisakazu; Sakai, Akihiro

JAEA-Technology 2022-013, 200 Pages, 2022/08

JAEA-Technology-2022-013.pdf:8.41MB

Japan Atomic Energy Agency has aims to carry out near surface disposal of low-level radioactive waste generated from research, medical, and industrial facilities. Therefore, Radioactivity Concentration Corresponding to Dose Criterion for near surface disposal for nuclides in the waste were calculated for the purpose of discussion for radioactivity limits between trench and concrete vault disposal, and key nuclides related to them. This report uses the results of sensitivity analysis and evaluation of the amount of leachate from the disposal facility for concrete vault disposal, and incorporates a new assessment pathway and exposure form that widely assume the conditions of the disposal facility. This trial calculation was carried out and compared with the trial calculation in the previous report, "Evaluation of Radioactivity Concentration Corresponding to Dose Criterion for Near Surface Disposal of Radioactive Waste Generated from Research, Medical, and Industrial Facilities, Volume 1". The results of Radioactivity Concentration Corresponding to Dose Criterion calculated in this report will be used as reference values when selecting key nuclides and for classification into concrete vault disposal when the location has not been decided. After deciding the location of the site, it is necessary to evaluate the dose based on the location conditions.

Journal Articles

Bayesian sparse modeling of extended X-ray absorption fine structure to determine interstitial oxygen positions in yttrium oxyhydride epitaxial thin film

Kumazoe, Hiroyuki*; Igarashi, Yasuhiko*; Iesari, F.*; Shimizu, Ryota*; Komatsu, Yuya*; Hitosugi, Taro*; Matsumura, Daiju; Saito, Hiroyuki*; Iwamitsu, Kazunori*; Okajima, Toshihiko*; et al.

AIP Advances (Internet), 11(12), p.125013_1 - 125013_5, 2021/12

 Times Cited Count:1 Percentile:8.23(Nanoscience & Nanotechnology)

Journal Articles

Design for detecting recycling muon after muon-catalyzed fusion reaction in solid hydrogen isotope target

Okutsu, Kenichi*; Yamashita, Takuma*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.

Fusion Engineering and Design, 170, p.112712_1 - 112712_4, 2021/09

 Times Cited Count:3 Percentile:47.54(Nuclear Science & Technology)

A muonic molecule which consists of two hydrogen isotope nuclei (deuteron (d) or tritium (t)) and a muon decays immediately via nuclear fusion and the muon will be released as a recycling muon, and start to find another hydrogen isotope nucleus. The reaction cycle continues until the muon ends up its lifetime of 2.2 $$mu$$s. Since the muon does not participate in the nuclear reaction, the reaction is so called a muon catalyzed fusion ($$mu$$CF). The recycling muon has a particular kinetic energy (KE) of the muon molecular orbital when the nuclear reaction occurs. Since the KE is based on the unified atom limit where distance between two nuclei is zero. A precise few-body calculation estimating KE distribution (KED) is also in progress, which could be compared with the experimental results. In the present work, we observed recycling muons after $$mu$$CF reaction.

Journal Articles

Time evolution calculation of muon catalysed fusion; Emission of recycling muons from a two-layer hydrogen film

Yamashita, Takuma*; Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.

Fusion Engineering and Design, 169, p.112580_1 - 112580_5, 2021/08

 Times Cited Count:3 Percentile:47.54(Nuclear Science & Technology)

A muon ($$mu$$) having 207 times larger mass of electron and the same charge as the electron has been known to catalyze a nuclear fusion between deuteron (d) and triton (t). These two nuclei are bound by $$mu$$ and form a muonic hydrogen molecular ion, dt$$mu$$. Due to the short inter-nuclear distance of dt$$mu$$, the nuclear fusion, d +t$$rightarrow alpha$$ + n + 17.6 MeV, occurs inside the molecule. This reaction is called muon catalyzed fusion ($$mu$$CF). Recently, the interest on $$mu$$CF is renewed from the viewpoint of applications, such as a source of high-resolution muon beam and mono-energetic neutron beam. In this work, we report a time evolution calculation of $$mu$$CF in a two-layered hydrogen isotope target.

Journal Articles

Dynamical response of transition-edge sensor microcalorimeters to a pulsed charged-particle beam

Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I.-H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.

IEEE Transactions on Applied Superconductivity, 31(5), p.2101704_1 - 2101704_4, 2021/08

 Times Cited Count:1 Percentile:11.71(Engineering, Electrical & Electronic)

A superconducting transition-edge sensor (TES) microcalorimeter is an ideal X-ray detector for experiments at accelerator facilities because of good energy resolution and high efficiency. To study the performance of the TES detector with a high-intensity pulsed charged-particle beam, we measured X-ray spectra with a pulsed muon beam at the Japan Proton Accelerator Research Complex (J-PARC) in Japan. We found substantial temporal shifts of the X-ray energy correlated with the arrival time of the pulsed muon beam, which was reasonably explained by pulse pileup due to the incidence of energetic particles from the initial pulsed beam.

JAEA Reports

Study on the radioactivity evaluation method of biological shielding concrete of JPDR for near surface disposal

Kochiyama, Mami; Okada, Shota; Sakai, Akihiro

JAEA-Technology 2021-010, 61 Pages, 2021/07

JAEA-Technology-2021-010.pdf:3.56MB
JAEA-Technology-2021-010(errata).pdf:0.75MB

It is necessary to evaluate the radioactivity inventory in wastes in order to dispose of radioactive wastes generated from dismantling nuclear reactor in the shallow ground. In this report, we examined radioactivity evaluation method for near surface disposal about biological shield concrete near the core generated from the dismantling of JPDR. We calculated radioactive concentration of the target biological concrete using the DORT code and the ORIGEN-S code, and we estimated radioactivity concentration Di (Bq/t). For DORT calculation, the cross-section library created from the MATXSLIB-J40 file from JENDL-4.0 was used, and for ORIGEN-S, the attached library of SCALE6.0 was used. As a result of comparing the calculation results of the radioactivity concentration with the past measured values in the radial direction and the vertical direction, we found that the trends were generally the same. We calculated radioactive concentration of the target biological concrete Di (Bq/t), and we compared with the estimated Ci (Bq/t) equivalent to the dose criteria of trench disposal calculated for 140 nuclides. As a result we inferred that the except for about 2% of target waste could be disposed of in the trench disposal facility. We also preselected important nuclides for trench disposal based on the ratios (Di/Ci) for each nuclide, H-3, C-14, Cl-36, Ca-41, Co-60, Sr-90, Eu-152 and Cs-137 were selected as important nuclides.

Journal Articles

Deexcitation dynamics of muonic atoms revealed by high-precision spectroscopy of electronic $$K$$ X rays

Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.

Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07

 Times Cited Count:9 Percentile:78.48(Physics, Multidisciplinary)

We observed electronic $$K$$X rays emitted from muonic iron atoms using a superconducting transition-edge-type sensor microcalorimeter. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic $$K$$$$alpha$$ and $$K$$$$beta$$ X rays together with the hypersatellite $$K$$$$alpha$$ X rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the $$L$$-shell electrons, accompanied by electron side-feeding. Assisted by a simulation, this data clearly reveals the electronic $$K$$- and $$L$$-shell hole production and their temporal evolution during the muon cascade process.

JAEA Reports

Basic policy for rational measures of radioactive waste processing and disposal; Results of studies for acceleration of waste processing

Nakagawa, Akinori; Oyokawa, Atsushi; Murakami, Masashi; Yoshida, Yukihiko; Sasaki, Toshiki; Okada, Shota; Nakata, Hisakazu; Sugaya, Toshikatsu; Sakai, Akihiro; Sakamoto, Yoshiaki

JAEA-Technology 2021-006, 186 Pages, 2021/06

JAEA-Technology-2021-006.pdf:54.45MB

Radioactive wastes generated from R&D activities have been stored in Japan Atomic Energy Agency. In order to reduce the risk of taking long time to process legacy wastes, countermeasures for acceleration of waste processing and disposal were studied. Work analysis of waste processing showed bottleneck processes, such as evaluation of radioactivity concentration, segregation of hazardous and combustibles materials. Concerning evaluation of radioactivity concentration, a radiological characterization method using a scaling factor and a nondestructive gamma-ray measurement should be developed. The number of radionuclides that are to be selected for the safety assessment of the trench type disposal facility can decrease using artificial barriers. Hazardous materials, will be identified using records and nondestructive inspection. The waste identified as hazardous will be unpacked and segregated. Preliminary calculations of waste acceptance criteria of hazardous material concentrations were conducted based on environmental standards in groundwater. The total volume of the combustibles will be evaluated using nondestructive inspection. The waste that does not comply with the waste acceptance criteria should be mixed with low combustible material waste such as dismantling concrete waste in order to satisfy the waste acceptance criteria on a disposal facility average. It was estimated that segregation throughput of compressed waste should be increased about 5 times more than conventional method by applying the countermeasures. Further study and technology development will be conducted to realize the plan.

JAEA Reports

Evaluation of radioactivity concentration corresponding to dose criterion for near surface disposal of radioactive waste generated from research, medical, and industrial facilities, Volume 1

Sugaya, Toshikatsu; Abe, Daichi*; Okada, Shota; Nakata, Hisakazu; Sakai, Akihiro

JAEA-Technology 2021-004, 79 Pages, 2021/05

JAEA-Technology-2021-004.pdf:2.86MB
JAEA-Technology-2021-004(errata).pdf:0.38MB

JAEA has aims to carry out near surface disposal of low-level radioactive waste generated from research, medical, and industrial facilities. Therefore, radioactivity concentration corresponding to dose criteria of near surface disposal for 220 nuclides in the waste were calculated for the purpose of discussion for radioactivity limits between trench and concrete vault disposal, and key nuclides related to them. We calculated the radioactivity concentrations with consideration of not only the exposure pathways used at calculation of the radioactivity concentration limits of waste packages for near surface disposal by Nuclear Safety Commission but also ones used at the concentration limits for intermediate depth disposal. We also assumed the capacities of the disposal facilities as 44,000 m$$^{3}$$ for pit disposal and 150,000 m$$^{3}$$ for trench disposal. The radioactivity concentrations calculated in this report is used as the reference values because the disposal site has not been decided yet. Addition to this, the radioactivity concentrations will be revised according to circumstances of development of disposal facilities and so on. In the future, we will decide the radioactivity and radioactive concentration of a waste package described in the license application documents based on the dose assessment taken into consideration the disposal site conditions.

JAEA Reports

Design and production of the valve used in Radioactive Liquid Disposal Facility

Nishimura, Arashi; Okada, Yuji; Sugaya, Naoto; Sonobe, Hiroshi; Kimura, Nobuaki; Kimura, Akihiro; Hanawa, Yoshio; Nemoto, Hiroyoshi

JAEA-Technology 2021-003, 51 Pages, 2021/05

JAEA-Technology-2021-003.pdf:5.55MB

In the Japan Materials Testing Reactor (JMTR), the leakage accidents of radioactive waste liquid were occurred from the tanks and pipes of the liquid waste disposal facility in the JMTR tank-yard building in JFY2014. In order to respond to the accident, obtain the approval of the JAEA to the design and construction method from JFY2016, the tanks and pipes were replaced from JFY2016 to 2019. In the replaced, the production of the tanks and pipes of the liquid waste disposal facility applied Japanese technical standards correspondingly. On the other hand, the valve did not fall under the category of Japanese technical standards. The manufacturing specifications when replacing the valve were decided based on the including the selecting the standards of production and inspection for valves, Fluid properties, experience in JMTR. The production proceeded while carrying out the decided inspection. The valves that passed all the inspections were installed together with the tanks and pipes of the liquid waste, and the finished inspection was performed as a systems. The construction was completed with those inspection passed. This report is summarized valve Design, production and installation.

Journal Articles

Thermally altered subsurface material of asteroid (162173) Ryugu

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.

Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03

 Times Cited Count:30 Percentile:96.87(Astronomy & Astrophysics)

Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 $$^{circ}$$C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 $$^{circ}$$C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.

Journal Articles

Real-time ${{it in vivo}}$ dosimetry system based on an optical fiber-coupled microsized photostimulable phosphor for stereotactic body radiation therapy

Yada, Ryuichi*; Maenaka, Kazusuke*; Miyamoto, Shuji*; Okada, Go*; Sasakura, Aki*; Ashida, Motoi*; Adachi, Masashi*; Sato, Tatsuhiko; Wang, T.*; Akasaka, Hiroaki*; et al.

Medical Physics, 47(10), p.5235 - 5249, 2020/10

 Times Cited Count:7 Percentile:53.18(Radiology, Nuclear Medicine & Medical Imaging)

The ${{it in vivo}}$ dosimeter system is capable of real-time, accurate, and precise measurement under stereotactic body radiation therapy (SBRT) conditions. The probe is smaller than a conventional dosimeter, has excellent spatial resolution, and can be valuable in SBRT with a steep dose distribution over a small field. The developed PSP dosimeter system appears to be suitable for in vivo SBRT dosimetry.

JAEA Reports

Validation of repairing method for concrete wall of the JMTR tank-yard building

Sugaya, Naoto; Okada, Yuji; Nishimura, Arashi; Sonobe, Hiroshi; Kimura, Nobuaki; Kimura, Akihiro; Hanawa, Yoshio; Nemoto, Hiroyoshi

JAEA-Testing 2020-004, 67 Pages, 2020/08

JAEA-Testing-2020-004.pdf:8.17MB

In the Japan Materials Testing Reactor (JMTR), the leakage accidents of radioactive waste liquid were occurred from the tanks and pipes of the liquid waste disposal facility in the JMTR tank-yard building in JFY2014. In order to respond to the accident, the tanks and pipes were replaced from JFY2016 to 2019. On the other hand, a lot of cracks were occurred on the concreate wall of the tank-yard building when the frame structure supports were fixed to the concrete wall in the replacement work. Thus, it is necessary to repair the concreate wall of the tank-yard building. Especially, some cracks with swelling (cone-shaped fracture) were raised around some anchor bolts (the post-installed chemical anchor bolts) fixed the frame structure supports. The repairing method for the cone-shaped fracture of the concrete wall is standardized, but there was no reference value of tensile strength for the validation of the post-installed chemical anchor bolts after the repairing method. In this report, the repairing method was selected for the cone-shaped fracture on the concreate wall and the reference value of tensile strength for the validation of the post-installed chemical anchor bolts by this repairing method. The mock-ups for repairing cone-shaped fracture were fabricated by the selected repairing method and the tensile tests of the post-installed chemical anchor bolts were performed. From the results, the validation of the repairing method was obtained in this test and it was obvious the repairing of cone-shaped fracture is preferable method for the concreate wall of the JMTR tank-yard building.

Journal Articles

$$omega N$$ scattering length from $$omega$$ photoproduction on the proton near the reaction threshold

Ishikawa, Takatsugu*; Fujimura, Hisako*; Fukasawa, Hiroshi*; Hashimoto, Ryo*; He, Q.*; Honda, Yuki*; Hosaka, Atsushi; Iwata, Takahiro*; Kaida, Shun*; Kasagi, Jirota*; et al.

Physical Review C, 101(5), p.052201_1 - 052201_6, 2020/05

Journal Articles

The Surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy

Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Arai, Takehiko*; Nakauchi, Yusuke*; Nakamura, Tomoki*; Matsuoka, Moe*; et al.

Science, 364(6437), p.272 - 275, 2019/04

 Times Cited Count:233 Percentile:99.74(Multidisciplinary Sciences)

The near-Earth asteroid 162173 Ryugu, the target of Hayabusa2 sample return mission, is believed to be a primitive carbonaceous object. The Near Infrared Spectrometer (NIRS3) on Hayabusa2 acquired reflectance spectra of Ryugu's surface to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micron was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally- and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.

Journal Articles

Development of waste acceptance criteria and current challenges relating to the disposal project of LLW generated in research, medical and industrial facilities

Nakata, Hisakazu; Amazawa, Hiroya; Izumo, Sari; Okada, Shota; Sakai, Akihiro

Dekomisshoningu Giho, (58), p.10 - 23, 2018/09

Low level radioactive wastes are generated in the research and development of the nuclear energy, medical and industrial use of radioisotope except NPP in Japan. The disposal of wastes arising from NPP has already been implemented while not the one for wastes from research institutes etc. Japan Atomic Energy Agency therefore has been assigned an implementing organization for the disposal legally in 2008 in order to promote the disposal program as quickly and firmly as possible. Since then, JAEA has conducted their activity relating to the disposal facility design on generic site conditions and developing Waste Acceptance Criteria for LLW from research institutes. This report summarizes the WAC and current challenges.

Journal Articles

First direct mass measurements of nuclides around $$Z$$ = 100 with a multireflection time-of-flight mass spectrograph

Ito, Yuta*; Schury, P.*; Wada, Michiharu*; Arai, Fumiya*; Haba, Hiromitsu*; Hirayama, Yoshikazu*; Ishizawa, Satoshi*; Kaji, Daiya*; Kimura, Sota*; Koura, Hiroyuki; et al.

Physical Review Letters, 120(15), p.152501_1 - 152501_6, 2018/04

 Times Cited Count:56 Percentile:93.55(Physics, Multidisciplinary)

Masses of $$^{246}$$Es, $$^{251}$$Fm and the transfermium nuclei $$^{249-252}$$Md, and $$^{254}$$No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed $$N=152$$ neutron shell closure, have been directly measured using a multi-reflection time-of-flight mass spectrograph. The masses of $$^{246}$$Es and $$^{249,250,252}$$Md were measured for the first time. Using the masses of $$^{249,250}$$Md as anchor points for $$alpha$$ decay chains, the masses of heavier nuclei, up to $$^{261}$$Bh and $$^{266}$$Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter $$delta_{2n}$$ derived from three isotopic masses was updated with the new masses and corroborate the existence of the deformed $$N=152$$ neutron shell closure for Md and Lr.

Journal Articles

Development of the reasonable confirmation methods concerning radioactive wastes from research facilities

Hayashi, Hirokazu; Okada, Shota; Izumo, Sari; Hoshino, Yuzuru; Tsuji, Tomoyuki; Nakata, Hisakazu; Sakai, Akihiro; Amazawa, Hiroya; Sakamoto, Yoshiaki

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04

A near surface disposal for low-level radioactive waste (LLW) generated from commercial nuclear power plants (NPP) is operating in Japan. However, the disposal of LLW from other nuclear facilities and radioisotope utilization facilities has not yet been implemented. Japan Atomic Energy Agency (JAEA) plans to implement the near surface disposal. In order to be disposed of these wastes, it must be confirmed by the regulator that each waste package (radioactive waste solidified with filling materials, such as cement, in a container by a regulated method is termed a waste package) conforms to technical standards that aim for safe disposal. JAEA has studied reasonable confirmation methods to demonstrate the conformity of the waste package to the technical standard as NPP operators have studied it. This report describes the outline of our activities focused on development of the confirmation method applicable to radioactive wastes from research facilities.

266 (Records 1-20 displayed on this page)