Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 24

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

Journal Articles

Incorporation of U, Pb and rare earth elements in calcite through crystallisation from amorphous calcium carbonate; Simple preparation of reference materials for microanalysis

Miyajima, Yusuke*; Saito, Ayaka*; Kagi, Hiroyuki*; Yokoyama, Tatsunori; Takahashi, Yoshio*; Hirata, Takafumi*

Geostandards and Geoanalytical Research, 45(1), p.189 - 205, 2021/03

 Times Cited Count:0 Percentile:0.01(Geochemistry & Geophysics)

Uncertainty for elemental and isotopic analyses of calcite by LA-ICP-MS is largely controlled by the homogeneity of the reference materials (RMs) used for normalization and validation. In order to produce calcite RMs with homogeneous elemental and isotopic compositions, we incorporated elements including U, Pb, and rare earth elements into calcite through heat- and pressure-induced crystallization from amorphous calcium carbonate that was precipitated from element-doped reagent solution. X-ray absorption spectra showed that U was present as U(VI) in the synthesized calcite, probably with a different local structure from that of aqueous uranyl ions. The uptake rate of U by our calcite was higher in comparison to synthetic calcite of previous studies. Variations of element mass fractions in the calcite were better than 12% 2RSD, mostly within 7%. The $$^{207}$$Pb/$$^{206}$$Pb ratio in the calcite showed $$<$$1% variations, while the $$^{238}$$U/$$^{206}$$Pb ratio showed 3-24% variations depending on element mass fractions. Using the synthetic calcite as primary RMs, we could date a natural calcite RM, WC-1, with analytical uncertainty as low as $$<$$3%. The method presented can be useful to produce calcite with controlled and homogeneous element mass fractions, and is a promising alternative to natural calcite RMs for U-Pb geochronology.

Journal Articles

Study on restricted use of contaminated rubble on Fukushima Daiichi NPS site, 2; Validation of reference radiocesium concentration for recycling materials

Miwa, Kazuji; Shimada, Taro; Takeda, Seiji

Progress in Nuclear Science and Technology (Internet), 6, p.166 - 170, 2019/01

In this study, in order to validate the restricted use of recycling material at the reference radiocesium concentration (determined in series report (1)), we evaluated worker annual doses, air dose rate at the site boundary and impact of migrated radiocesium into groundwater. Firstly, we evaluated the additional annual dose for workers, on the assumption that typical workers coming in contact with the source after construction (Road: 1.2 mSv/y, Building: 1.3 mSv/y). Secondly, we evaluated the air dose rates by distance from road and building including recycling material, and investigated the distance for not exceeding 1 mSv/y (including additional dose rate by recycling and background dose rate of 0.6 mSv/y) at the site boundary (Road: 25 m, Building: 1 m). Thirdly, we evaluated the Cs migration in groundwater, and investigated the distance required for satisfying the operation target value ($$^{134}$$Cs: 1 Bq/L, $$^{137}$$Cs: 1 Bq/L) at the boundary (coastal line) (Road: 10 m, Building: 10 m).

Journal Articles

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

 Times Cited Count:0 Percentile:0.01(Environmental Sciences)

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.

Journal Articles

Design of a single moderator-type neutron spectrometer with enhanced energy resolution in energy range from a few to 100 keV

Tanimura, Yoshihiko; Saegusa, Jun; Yoshizawa, Michio; Yoshida, Makoto

Nuclear Instruments and Methods in Physics Research A, 547(2-3), p.592 - 600, 2005/08

 Times Cited Count:7 Percentile:50.55(Instruments & Instrumentation)

The moderator structure of a neutron spectrometer was optimized with a Monte Carlo code of MCNP-4B. The spectrometer consists of a cylindrical moderator and a position-sensitive thermal neutron detector. It can obtain an energy spectrum from thermal neutron distribution along the cylindrical axis of the moderator. The structure of the moderator was improved by putting a low hydrogen density material in the front of a high hydrogen density one and inserting a neutron absorber which eliminated thermal neutrons diffusing in the moderator. These improvements make energy resolution of the spectrometer better especially for the low energy neutrons from a few tens to 100 keV. The designed spectrometer can be applied to the measurement of energy spectrum over a neutron energy range from a few keV to 20 MeV.

JAEA Reports

Characterization of the nuclear power plants in decommissioning program and influence evaluation on decommissioning costs

Mizukoshi, Seiji; Oshima, Soichiro; Shimada, Taro

JAERI-Tech 2005-011, 122 Pages, 2005/03

JAERI-Tech-2005-011.pdf:13.25MB

The radiological and physical characteristic on decommissioning, such as component and structure weights and radioactivity of the 1.1 MWe class reference nuclear power plants summarized in the NUREG reports of the US NRC were classified,arranged and compared with the domestic commercial nuclear power plants and JPDR from a view point of dismantling plan and waste management for decommissioning. As the results, it was found that the radioactive component and structure weights was about 28,000ton、and non-radioactive structure weights was about 124,000ton less than the domestic commercial BWR. And it was found that this differences has mainly influenced dismantling costs for decommissioning. Farther, it was found that the concrete element composition rates of B, Ni, Nb and so were differerence of one or more figures btween the reference nuclear power plants and the domestic commercial PWR or JPDR.Also,it was found that the this difference became about two or three times by radioactivity concentration and has mainly influenced transport and disposal costs for decommissioning.

Journal Articles

Multi-element determination in soil and sediment reference materials by neutron-induced prompt $$gamma$$-ray analysis using ${it k}$$$_{0}$$-standardization

Matsue, Hideaki; Yonezawa, Chushiro

Bunseki Kagaku, 53(7), p.749 - 751, 2004/07

 Times Cited Count:0 Percentile:0.01(Chemistry, Analytical)

Multi-element determination in reference materials of soils (JASC401, JASC411) and sediments (NMIJ CRM 7302-a, NMIJ CRM 7303-a), which were prepared at the Japan Society for Analytical Chemistry and the National Institute of Advanced Industrial Science and Technology of the National Metrology Institute of Japan, respectively, has been carried out by neutron-induced prompt $$gamma$$-ray analysis (PGA) using standard addition and ${it k}$$$_{0}$$-standardization methods. Firstly, absolute Ti concentrations in the samples were determined accurately by the standard addition method. Secondly, relative multi-element concentrations were determined by the ${it k}$$$_{0}$$-standardization method. Finally, absolute multi-element concentrations were obtained by normalizing the relative multi-element concentrations with the absolute Ti concentration in the samples. The 15 elements such as H, B, Na, Si, S, Cl, K, Ca, Ti Cr, Mn, Fe, Cd, Sm and Gd were determined by the ${it k}$$$_{0}$$-PGA. Analytical results of these reference materials agreed with the certified or reference values within about 10%.

JAEA Reports

Establishment of X-ray reference fields for performance tests of radiation measuring instruments based on international standard(ISO4037-1)

Shimizu, Shigeru; Zhang, Q.; Kajimoto, Yoichi; Kawasaki, Tomokatsu; Fujii, Katsutoshi

JAERI-Tech 2003-095, 52 Pages, 2004/01

JAERI-Tech-2003-095.pdf:2.66MB

The International Standards ISO4037-1 of the International Organization for Standardization widely applied in the world to construct X-ray reference fields for performance tests of radiation measuring instruments. The application of the current JAERI's X-ray reference field constructed in accordance with the Japanese Standards should be limited for domestic purposes becase of the characterization technique different from the International Standards. Therefore,for application to international performance tests, X-ray reference fields in the narrow,wide and high air-kerma series based on the International Standards were established using the medium-hard X-ray generator of the Facility of Radiation Standards(FRS), JAERI. This report presents quality characterization, estimation of X-ray spectra of each dose units of the new FRS's fields,and comparison of the qualities and the X-ray spectra to those of the ISO's. The FRS's qualities show good agreement with ISO's: the reference fields should serve for performance tests for international radiation protection purposes.

Journal Articles

Reference solutions for 3-D radiation transport benchmarks by a Monte Carlo code GMVP

Nagaya, Yasunobu

Progress in Nuclear Energy, 39(2), p.145 - 153, 2001/08

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Characterization and evaluation studies on some JAERI dosimetry systems

Kojima, Takuji; Sunaga, Hiromi; Tachibana, Hiroyuki; Takizawa, Haruki; Tanaka, Ryuichi

IAEA-TECDOC-156, p.91 - 98, 2000/06

no abstracts in English

Journal Articles

Comparison of the flat and linear source variants of the method of characteristics

Petkov, P.*; Takeda, Toshikazu*; Mori, Takamasa

Annals of Nuclear Energy, 26(10), p.935 - 942, 1999/00

no abstracts in English

Journal Articles

Sterilization and disinfection methods based on the Japanese pharmacopoeia

Kojima, Takuji; Tanaka, Ryuichi

Nihon Yakkyokuho Ni Junkyoshita Mekkinho Oyobi Biseibutsu Satsumetsuho, p.74 - 82, 1997/00

no abstracts in English

Journal Articles

Reference parameters and default values

Togawa, Orihiko

Shinkokyu Kido Moderu; Gaiyo To Kaisetsu, 0, p.74 - 85, 1995/03

no abstracts in English

Journal Articles

Thin film alanine-polyethylene dosimeter

Kojima, Takuji; H.L.A.Ranjith*; Haruyama, Yasuyuki; Kashiwazaki, Shigeru*; Tanaka, Ryuichi

Applied Radiation and Isotopes, 44(1-2), p.41 - 45, 1993/00

 Times Cited Count:12 Percentile:75.41(Chemistry, Inorganic & Nuclear)

no abstracts in English

Journal Articles

Benchmark calculation for deep penetration problem of 14MeV neutrons in iron

Mori, Takamasa; Nakakawa, Masayuki

Journal of Nuclear Science and Technology, 29(11), p.1061 - 1073, 1992/11

no abstracts in English

Journal Articles

Improvement of Rocchios measures for output; Ranking performance in reference retrieval

Ebinuma, Yukio

Int.Inf.Commun.Educ., 6(1), p.45 - 54, 1987/01

no abstracts in English

Journal Articles

Irradiation experiments of VHTR reference fuels by an in-pile gas loop(OGL-1)

; ; ; Minato, Kazuo; ; Ikawa, Katsuichi

Nihon Genshiryoku Gakkai-Shi, 26(1), p.57 - 74, 1984/00

 Times Cited Count:1 Percentile:19.62(Nuclear Science & Technology)

no abstracts in English

JAEA Reports

Journal Articles

Biological half-life of radioiodine in normal Japanese thyroid

Hoken Butsuri, 18(1), p.3 - 10, 1983/00

no abstracts in English

JAEA Reports

Journal Articles

Evaluation of automatic ranking scheme in the INIS reference retrieval system

INFORMAT, 1(2), p.201 - 216, 1982/02

no abstracts in English

24 (Records 1-20 displayed on this page)