Calculation of fluence-to-effective dose conversion coefficients for the operational quantity proposed by ICRU RC26

Endo, Akira

Radiation Protection Dosimetry, 175(3), p.378 - 387, 2017/07

https://doi.org/10.1093/rpd/ncw361

The International Commission on Radiation Units and Measurements (ICRU) has been discussing to propose a new system of the operational quantities for external radiations based on protection quantities. The aim of this study is to provide a set of conversion coefficients for use in defining personal dose equivalent for individual monitoring. Fluence-to-effective dose conversion coefficients have been calculated for photons, neutrons, electrons, positrons, protons, muons, pions and helium ions for various incident angles of radiations. The data sets comprise effective dose conversion coefficients for incident angles of radiations from 0 to 90 in steps of 15 and at 180. Conversion coefficients for rotational, isotropic, superior hemisphere semi-isotropic and inferior hemisphere semi-isotropic irradiations are also included. The conversion coefficients are used to define the operational quantity personal dose equivalent which is being considered by ICRU and utilized for the design and calibration of dosemeters.

Femtosecond time-resolved solvation process of a solution; Constraints of vibrational degrees of freedom in the supercooled state

Murakami, Hiroshi

Chemical Physics Letters, 417(4-6), p.550 - 554, 2006/01

https://doi.org/10.1016/j.cplett.2005.10.072

no abstracts in English

Concept of Innovative Water Reactor for Flexible Fuel Cycle (FLWR)

Iwamura, Takamichi; Uchikawa, Sadao; Okubo, Tsutomu; Kugo, Teruhiko; Akie, Hiroshi; Nakatsuka, Toru

Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), 8 Pages, 2005/05

In order to ensure sustainable energy supply in the future based on the matured Light Water Reactor (LWR) and coming LWR-Mixed Oxide (MOX) technologies, a concept of Innovative Water Reactor for Flexible Fuel Cycle (FLWR) has been investigated in Japan Atomic Energy Research Institute (JAERI). The concept consists of two parts in the chronological sequence. The first part realizes a high conversion type core concept, which is basically intended to keep the smooth technical continuity from current LWR without significant gaps in technical point of view. The second part represents the Reduced-Moderation Water Reactor (RMWR) core concept, which realizes a high conversion ratio over 1.0 being useful for the long-term sustainable energy supply through plutonium multiple recycling based on the well-experienced LWR technologies. The key point is that the two core concepts utilize the compatible and the same size fuel assemblies, and hence, the former concept can proceed to the latter in the same reactor system, based flexibly on the fuel cycle circumstances.

Optimization of seed-blanket type fuel assembly for reduced-moderation water reactor

Shelley, A.; Shimada, Shoichiro*; Kugo, Teruhiko; Okubo, Tsutomu; Iwamura, Takamichi

Nuclear Engineering and Design, 224(3), p.265 - 278, 2003/10

https://doi.org/10.1016/S0029-5493(03)00107-9

Parametric studies have been done for a PWR-type reduced-moderation water reactor (RMWR) with seed-blanket fuel assembles to achieve a high conversion ratio, negative void reactivity coefficient and a high burnup. It was found that 50 to 60% of seed in a seed-blanket assembly has higher conversion ratio. The number of seed-blanket layers is 20, in which the number of seed layers is 15 and blanket layers is 5. The fuel assembly with the height of seed of 1000mm2, internal blanket of 150 mm and axial blanket of 400mm2 is recommended. The conversion ratio is 1.0 and the average burnup in core region is 38.2 GWd/t. The enrichment of fissile Pu is 14.6 wt%. The void coefficient is +21.8 pcm/% void, however, it is expected that the void coefficient will be negative if the radial neutron leakage is taken into account. It is also possible to use this fuel assembly for a high core averaged burnup of 45GWd/t, however, the height of seed must be 500mm2 to improve the void coefficient. The conversion ratio is 0.97 and void coefficient is +20.8 pcm/%void.

Research and development of Reduced-Moderation Water Reactor (RMWR)

Iwamura, Takamichi; Okubo, Tsutomu

Proceedings of 2nd Asian Specialist Meeting on Future Small-Sized LWR Development, p.7_1 - 7_5, 2003/00

An innovative water-cooled reactor concept named Reduced-Moderation Water Reactor (RMWR) is under development at JAERI, aiming at effective fuel utilization through plutonium (Pu) multiple recycling based on the well-experienced water-cooled reactor technology. The reactor is able to achieve a high conversion ratio more than 1.0 with MOX fuel, to establish the sustainable Pu recycling. Such a high conversion ratio can be attained by reducing the moderation of neutrons, i.e. reducing the water fraction in the core. Detailed research and development activities have been performed on the core design, in conjunction with the other related studies such as on the thermal hydraulics in the tight-lattice core, the reactor physics and the fuel irradiation behavior, including the experimental activities. Also, for the total feasibility demonstration of the RMWR technologies, a design investigation for Reduced-Moderation Demonstration Reactor (RMDR) of 180MWt is being performed.

Development of Reduced-Moderation Water Reactor (RMWR) for sustainable energy supply

Iwamura, Takamichi; Okubo, Tsutomu; Kureta, Masatoshi; Nakatsuka, Toru; Takeda, Renzo*; Yamamoto, Kazuhiko*

Proceedings of 13th Pacific Basin Nuclear Conference (PBNC 2002) (CD-ROM), 7 Pages, 2002/10

In order to ensure sustainable energy supply in Japan, the reduced-moderation water reactor (RMWR) has been developed by JAERI since 1998. MOX fuel assemblies with tight lattice arrangement are used to increase the conversion ratio. In order to establish negative void reactivity coefficient, the core should be short and flat to increase neutron leakage from the core. The core designs were accomplished to a large core with 1,356MWe and a small core with 330MWe. For both cores, negative void coefficient and natural circulation cooling of the core were realized. To confirm thermal-hydraulic feasibility, critical heat flux experiments were performed using 7-rod bundles with the gap width of 1mm and 1.3mm. The results indicated that enough cooling was assured for the tight lattice core. Further R&D studies, including large scale thermal-hydraulic experiments, reactor physics experiments, development of high burn-up fuel cladding material and simplified reprocessing technology, are necessary to realize commercial introduction of RMWR by 2020's for the replacement of current generation LWRs.

25-J green-beam generation with large aperture CsLiBO crystals

Kiriyama, Hiromitsu; Inoue, Norihiro*; Yagi, Kenichi*; Nagai, Toru*; Aoyama, Makoto; Yamakawa, Koichi

Proceedings of Conference on Lasers and Electro-Optics / Quantum Electronics and Laser Science Conference (CLEO/QELS 2002), p.CPDC6_1 - CPDC6_3, 2002/00

no abstracts in English

High efficiency second-harmonic generation in multi-pass quadrature arrangement

Kiriyama, Hiromitsu; Nakano, Fumihiko*; Yamakawa, Koichi

JAERI-Research 2001-030, 26 Pages, 2001/05

JAERI-Research-2001-030.pdf:1.14MB

no abstracts in English

Development of methane conversion improvement method by recycling of residual Methane for steam reforming as a part of R&D of HTGR-hydrogen production system

Inagaki, Yoshiyuki; Haga, Katsuhiro; ; Sekita, Kenji; *; Hino, Ryutaro

Nihon Genshiryoku Gakkai-Shi, 40(1), p.59 - 64, 1998/00

https://doi.org/10.3327/jaesj.40.59

no abstracts in English

Modified conversion ratio measurement in light water-moderated UO lattices

Nakajima, Ken;

Nuclear Technology, 113, p.375 - 379, 1996/03

https://doi.org/10.13182/NT96-A35217

no abstracts in English