Stochastic estimation of radionuclide composition in wastes generated at Fukushima Daiichi Nuclear Power Station using Bayesian inference

Sugiyama, Daisuke*; Nakabayashi, Ryo*; Tanaka, Shingo*; Koma, Yoshikazu; Takahatake, Yoko

Journal of Nuclear Science and Technology, 58(4), p.493 - 506, 2021/04

https://doi.org/10.1080/00223131.2021.1884137

Integrating radiation protection criteria for radioactive waste management into remediation procedures in existing exposure situations after a nuclear accident

Sugiyama, Daisuke*; Kimura, Hideo; Tachikawa, Hirokazu*; Iimoto, Takeshi*; Kawata, Yosuke*; Ogino, Haruyuki*; Okoshi, Minoru*

Journal of Radiological Protection, 38(1), p.456 - 462, 2018/03

https://doi.org/10.1088/1361-6498/aaa155

Experience after the accident at the Fukushima Daiichi Nuclear Power Station has shown that there is a need to establish radiation protection criteria for radioactive waste management consistent with the criteria adopted for the remediation of existing exposure situations. A stepwise approach to setting such criteria is proposed. Initially, a reference level for annual effective dose from waste management activities in the range 1-10 mSv should be set, with the reference level being less than the reference level for ambient dose. Subsequently, the reference level for annual effective dose from waste management activities should be reduced in one or more steps to achieve a final target value of 1 mSv. The dose criteria at each stage should be determined with relevant stakeholder involvement. Illustrative case studies show how this stepwise approach might be applied in practice.

Removal of cesium using cobalt-ferrocyanide-impregnated polymer-chain-grafted fibers

Ishihara, Ryo*; Fujiwara, Kunio*; Harayama, Takato*; Okamura, Yusuke*; Uchiyama, Shoichiro*; Sugiyama, Mai*; Someya, Takaaki*; Amakai, Wataru*; Umino, Satoshi*; Ono, Tsubasa*; et al.

Journal of Nuclear Science and Technology, 48(10), p.1281 - 1284, 2011/10

AA2011-0190.pdf:0.45MB

https://doi.org/10.3327/jnst.48.1281

High-contrast (10), high-intensity (500 TW) J-KAREN laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Sasao, Hajime; Tanaka, Momoko; Ochi, Yoshihiro; Tanoue, Manabu*; Okada, Hajime; Kondo, Shuji; et al.

JAEA-Conf 2010-002, p.18 - 21, 2010/06

https://doi.org/10.11484/jaea-conf-2010-002

We have developed a femtosecond high intensity laser system, which combines both Ti:sapphire chirped-pulse amplification (CPA) and optical parametric chirped-pulse amplification (OPCPA) techniques, that produces more than 30 J broadband output energy, indicating the potential for achieving peak powers in excess of 500 TW. With a cleaned high-energy seeded OPCPA preamplifier as a front-end in the system, for the final compressed pulse (without pumping the booster amplifier) we found that the temporal contrast in this system exceeds 10 on the sub-nanosecond timescale, and is near 10 on the nanosecond timescale before the main femtosecond pulse. Using diffractive optical elements for beam homogenization of 100-J level high-energy Nd:glass green pump laser in a Ti:sapphire final amplifier, we have successfully generated broadband high-energy output with near-perfect top-hat intensity distributions.

High spatiotemporal-quality petawatt-class laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Sasao, Hajime; Tanaka, Momoko; Ochi, Yoshihiro; Tanoue, Manabu*; Okada, Hajime; Kondo, Shuji; et al.

Applied Optics, 49(11), p.2105 - 2115, 2010/04

https://doi.org/10.1364/AO.49.002105

We have developed a femtosecond high intensity laser system, which combines both Ti:sapphire chirped-pulse amplification (CPA) and optical parametric chirped-pulse amplification (OPCPA) techniques, that produces more than 30-J broadband output energy, indicating the potential for achieving peak powers in excess of 500-TW. With a cleaned high-energy seeded OPCPA preamplifier as a front-end in the system, for the compressed pulse without pumping the final amplifier we found that the temporal contrast in this system exceeds 10 on the sub-nanosecond timescales, and is near 10 on the nanosecond timescale prior to the peak of the main femtosecond pulse. Using diffractive optical elements for beam homogenization of 100-J level high-energy Nd:glass green pump laser in a Ti:sapphire final amplifier, we have successfully generated broadband high-energy output with a near-perfect top-hat-like intensity distribution.

Electron optical injection with head-on and countercrossing colliding laser pulses

Kotaki, Hideyuki; Daito, Izuru; Kando, Masaki; Hayashi, Yukio; Kawase, Keigo; Kameshima, Takashi*; Fukuda, Yuji; Homma, Takayuki; Ma, J.*; Chen, L. M.*; et al.

Physical Review Letters, 103(19), p.194803_1 - 194803_4, 2009/11

https://doi.org/10.1103/PhysRevLett.103.194803

Application study on low alkaline cementitious materials for deep geological repository of high level radioactive wastes, 2; Organization of previous finding and understanding of material properties of low alkaline cement (Joint research)

Kobayashi, Yasushi; Yamada, Tsutomu; Naito, Morimasa; Yui, Mikazu; Nakayama, Masashi; Sato, Haruo; Nishida, Takahiro*; Hironaga, Michihiko*; Yamamoto, Takeshi*; Sugiyama, Daisuke*; et al.

JAEA-Research 2009-013, 70 Pages, 2009/06

JAEA-Research-2009-013.pdf:8.85MB

Cementitious materials will be used to ensure construction and operational safety and work efficiency in a deep geological repository. The low alkaline cement has been developed to reduce uncertainties due to hyper alkaline for the long-term safety performance of the repository system. Functions of cementitious material required in each phase of repository construction, operation and closure were summarized in a separate report entitled "Application Study on Low Alkaline Cementitious Materials for Deep Geological Repository of High Level Radioactive Wastes (Phase I) "In this report, properties of low alkaline cement/concrete which have been developed both at home and abroad, and recipes of the low alkaline concrete taken account of application to the repository component have been investigated. Fresh and hardened properties of the low alkaline cement are equivalent to the OPC and the low alkaline cement has an advantage over OPC in terms of leaching resistance. The HFSC developed by JAEA, which belongs to a pozzolanic type low alkaline cement will be able to apply to the shotcrete and the lining concrete by choosing an adequate recipe. Clarification of influences of the chemical composition of groundwater on leachate properties of the hydrates, examination of pH measurement of cement leachate, evaluation of corrosion behavior of rebar embedded in the HFSC concrete are raised as open questions for future activities.

Application study on low alkaline cementitious materials for deep geological repository of high level radioactive wastes, 1; Requirements for use of cementitious materials in deep geological repository system (Joint research)

Kobayashi, Yasushi; Yamada, Tsutomu; Naito, Morimasa; Yui, Mikazu; Nakayama, Masashi; Sato, Haruo; Nishida, Takahiro*; Hironaga, Michihiko*; Yamamoto, Takeshi*; Sugiyama, Daisuke*; et al.

JAEA-Research 2008-112, 43 Pages, 2009/03

JAEA-Research-2008-112.pdf:4.58MB

In deep geological repository, use of cementitious material for rock support, lining, and grouting is essential for construction and operation and possibly raises in groundwater pH due to leachate from the cements. Since this hyperalkaline condition may lead to degradation of barriers, there is concern that it gives significant impact on long-term safety performance of the repository system. Because of these backgrounds, developments of low alkaline cement have been conducted both at home and abroad. JAEA is now planning to conduct an in-situ test for shotcreting using low alkaline cement at the Horonobe URL. On the other hand, CRIEPI has studied and developed cementitious materials for disposal of radioactive wastes. This joint research report summarizes requirements and expected performance of cementitious materials in repository taking account of surrounding conditions in each stage of the repository program so as to reflect them to further development of the low alkaline cement.

Change of the Fermi surface across the critical pressure in CeIn; The de Haas-van Alphen study under pressure

Settai, Rikio*; Kubo, Tetsuo*; Shiromoto, Tomoyuki*; Honda, Daisuke*; Shishido, Hiroaki*; Sugiyama, Kiyohiro*; Haga, Yoshinori; Matsuda, Tatsuma; Betsuyaku, Kiyoshi*; Harima, Hisatomo*; et al.

Journal of the Physical Society of Japan, 74(11), p.3016 - 3026, 2005/11

https://doi.org/10.1143/JPSJ.74.3016

We have studied a change of the Fermi surface in an antiferromagnet CeIn via the de Haas-van Alphen experiment under pressure up to 3 GPa. With increasing pressure P, the Neel temperature =10 K decreases and becomes zero at a critical pressure Pc 2.6 GPa. In the pressure region , we have observed a large main Fermi surface named a, which indicates that the electronic state of 4 f electron in CeIn changes from localized to itinerant at Pc, as observed in the similar antiferromagnets CeRhSi and CeRhIn. The cyclotron effective mass of this main Fermi surface is extremely enhanced around Pc: 60 at 2.7 GPa for the magnetic field along the 100 direction.

Hydrogen removal properties from JT-60 open divertor tile by pulsed laser ablation

Miya, Naoyuki; Watanabe, Daisuke*; Sakawa, Yoichi*; Shibahara, Takahiro*; Sugiyama, Kazuyoshi*; Shoji, Tatsuo*; Yamazaki, Kozo*; Masaki, Kei; Tanabe, Tetsuo*

no journal, , 

no abstracts in English