Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 88

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

Experimental study on transport behavior of cesium iodide in the reactor coolant system under LWR severe accident conditions

Miyahara, Naoya; Miwa, Shuhei; Gou$"e$llo, M.*; Imoto, Jumpei; Horiguchi, Naoki; Sato, Isamu*; Osaka, Masahiko

Journal of Nuclear Science and Technology, 57(12), p.1287 - 1296, 2020/12

 Times Cited Count:5 Percentile:78.35(Nuclear Science & Technology)

In order to clarify the cesium iodide (CsI) transport behavior with a focus on the mechanisms of gaseous iodine formation in the reactor coolant system of LWR under a severe accident condition, a reproductive experiment of CsI transport behavior was conducted using a facility equipped with a thermal gradient tube. Various analyses on deposits and airborne materials during transportation could elucidate two mechanisms for the gaseous iodine formation. One was the gaseous phase chemical reaction in Cs-I-O-H system at relatively high-temperature region, which led to gaseous iodine transport to the lower temperature region without any further changes in gas species due to the kinetics limitation effects. The other one was the chemical reactions related to condensed phase of CsI, namely those of CsI deposits on walls with surface of stainless steel to form Cs$$_{2}$$CrO$$_{4}$$ compound and CsI aerosol particles with steam, which were newly found in this study.

Journal Articles

An Experimental investigation of influencing chemical factors on Cs-chemisorption behavior onto stainless steel

Nishioka, Shunichiro; Nakajima, Kunihisa; Suzuki, Eriko; Osaka, Masahiko

Journal of Nuclear Science and Technology, 56(11), p.988 - 995, 2019/11

 Times Cited Count:9 Percentile:85.1(Nuclear Science & Technology)

In order to contribute to improvement of Cs chemisorption model used in severe accident analysis codes, the influence of chemical factors (temperature, atmosphere, concentration of affecting chemical elements etc.) on the Cs chemisorption behaviour onto stainless steel was investigated experimentally. It was found that the surface reaction rate constant used in the current Cs-chemisorption model was influenced by not only temperature, as already known, but also atmosphere, cesium hydroxide (CsOH) concentration in the gas phase and silicon content in SS304. Such chemical factors should be considered for the construction of the improved Cs-chemisorption model. Another important finding is that the chemisorption behavior at lower temperatures, around 873 K, could differ from those above 1073 K. Namely, Cs-Fe-O compounds would form as the main Cs-chemisorbed compounds at 873 K while Cs-Si-Fe-O compounds at more than 1073 K.

Journal Articles

Chemical reaction kinetics dataset of Cs-I-B-Mo-O-H system for evaluation of fission product chemistry under LWR severe accident conditions

Miyahara, Naoya; Miwa, Shuhei; Horiguchi, Naoki; Sato, Isamu*; Osaka, Masahiko

Journal of Nuclear Science and Technology, 56(2), p.228 - 240, 2019/02

 Times Cited Count:7 Percentile:78.09(Nuclear Science & Technology)

In order to improve LWR source term under severe accident conditions, the first version of a fission product (FP) chemistry database named "ECUME" was developed. The ECUME is intended to include major chemical reactions and their effective kinetic constants for representative SA sequences. It is expected that the ECUME can serve as a fundamental basis from which FP chemical models in the SA analysis codes can be elaborated. The implemented chemical reactions in the first version were those for representative gas species in Cs-I-B-Mo-O-H system. The chemical reaction kinetic constants were evaluated from either literature data or calculated values using ab-initio calculations. The sample chemical reaction calculation using the presently constructed dataset showed meaningful kinetics effects at 1000 K. Comparison of the chemical equilibrium compositions by using the dataset with those by chemical equilibrium calculations has shown rather good consistency for the representative Cs-I-B-Mo-O-H species. From these results, it was concluded that the present dataset should be useful to evaluate FP chemistry in Cs-I-B-Mo-O-H system under LWA SA conditions.

Journal Articles

Shielding

Maekawa, Fujio

Hamon, 28(4), p.208 - 211, 2018/11

Adequate shielding of neutrons and associated $$gamma$$-rays is of importance from viewpoints of the radiation safety of researchers and good experimental data taking by reducing the background. This article introduces basics of neutron shielding, physics and suitable materials for neutron and $$gamma$$-ray shielding, and an example of conceptual shielding design for the 1-MW spallation neutron source of J-PARC MLF.

Journal Articles

Development of experimental and analytical technologies for fission product chemistry under LWR severe accident condition

Miyahara, Naoya; Miwa, Shuhei; Nakajima, Kunihisa; Osaka, Masahiko

Proceedings of 2017 Water Reactor Fuel Performance Meeting (WRFPM 2017) (USB Flash Drive), 9 Pages, 2017/09

This paper presents the development of a reproductive experimental setup for FP release and transport and an analysis tool considering chemical reaction kinetics for the construction of the FP chemistry database. The performance test of the reproductive experimental setup TeRRa using CsI compounds show that TeRRa can reproduce well a FP chemistry-related behavior such as aerosol formation, growth and deposition behavior. An analytical tool has been developed based on the commercial ANSYS-FLUENT code. Some additional models was added to evaluate detailed FP chemistry during release and transport in this study. A test analysis simulating the CsI heating test in steam atmosphere was carried out to demonstrate the performance of the improved code. The result shows the appropriateness of the additional models.

Journal Articles

Hazard curve evaluation method development for a forest fire as an external hazard on nuclear power plants

Okano, Yasushi; Yamano, Hidemasa

Journal of Nuclear Science and Technology, 53(8), p.1224 - 1234, 2016/08

 Times Cited Count:3 Percentile:33.64(Nuclear Science & Technology)

A method to obtain a hazard curve of a forest fire was developed. The method has four steps: a logic tree formulation, a response surface evaluation, a Monte Carlo simulation, and an annual exceedance frequency calculation. The logic tree consists domains of forest fire breakout and spread conditions, weather conditions, vegetation conditions, and forest fire simulation conditions. The new method was applied to evaluate hazard curves of a reaction intensity and a fireline intensity for a typical location around a sodium-cooled fast reactor in Japan.

Journal Articles

Measurement of the $$^{77}$$Se($$gamma$$, n) cross section and uncertainty evaluation of the $$^{79}$$Se(n, $$gamma$$) cross section

Kitatani, Fumito; Harada, Hideo; Goko, Shinji*; Iwamoto, Nobuyuki; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Igashira, Masayuki*

Journal of Nuclear Science and Technology, 53(4), p.475 - 485, 2016/04

 Times Cited Count:2 Percentile:23.67(Nuclear Science & Technology)

Journal Articles

Nuclear data evaluation of the $$^7$$Li(p,xn) reaction for incident energies up to 200 MeV

Matsumoto, Yuiki*; Watanabe, Yukinobu*; Kunieda, Satoshi; Iwamoto, Osamu

JAEA-Conf 2015-003, p.191 - 196, 2016/03

Neutron emission from the $$^7$$Li(p,n)$$^7$$Be reaction can be divided into two components: a mono-energetic component for the transition to the ground and the 1st excited states and a continuum component formed by $$^7$$Li breakup processes. For the former, we have obtained the differential cross sections by interpolation based on Legendre fitting of available experimental data up to 45 MeV and apply DWBA calculations above 45 MeV. Next, we have applied the CCONE code to DDX calculations of the continuum component, and adjusted pre-equilibrium model parameters to reproduce experimental data well. Finally, both the results are merged and then the evaluated DDX data are completed.

JAEA Reports

Proceedings of the 2013 Symposium on Nuclear Data; November 14-15, 2013, Research Institute of Nuclear Engineering University of Fukui, Tsuruga, Fukui, Japan

Yamano, Naoki*; Iwamoto, Osamu; Nakamura, Shoji; Kunieda, Satoshi; Van Rooijen, W.*; Koura, Hiroyuki

JAEA-Conf 2014-002, 209 Pages, 2015/02

JAEA-Conf-2014-002.pdf:64.24MB

The 2013 Symposium on Nuclear Data was held at Research Institute of Nuclear Engineering, University of Fukui, on 14th and 15th of November 2013. The Nuclear Data Division of the Atomic Energy Society of Japan and Research Institute of Nuclear Engineering, University of Fukui organize this symposium in cooperation with Nuclear Science and Engineering Center of Japan Atomic Energy Agency and the Chubu Branch of Atomic Energy Society of Japan. In the oral sessions, papers were presented on topics of progress in neutron cross-section measurement and analysis, application of nuclear data, recent topics on nuclear data measurement and theory, and progress in studies of high-energy nuclear reactions. In the poster session, papers were presented concerning experiments, evaluations, benchmark tests and applications. This report consists of total 35 papers including 14 oral presentations and 21 poster presentations.

Journal Articles

Development of beam generation and irradiation technology for electrostatic accelerators

Chiba, Atsuya; Uno, Sadanori; Okoshi, Kiyonori; Yamada, Keisuke; Saito, Yuichi; Ishii, Yasuyuki; Sakai, Takuro; Sato, Takahiro; Mizuhashi, Kiyoshi

JAEA-Review 2005-001, TIARA Annual Report 2004, p.358 - 360, 2006/01

no abstracts in English

Journal Articles

Measurement of energetic charged particles produced in fusion materials with 14 MeV neutron irradiation

Ochiai, Kentaro; Kondo, Keitaro; Murata, Isao*; Miyamaru, Hiroyuki*; Kubota, Naoyoshi; Takahashi, Akito*; Nishitani, Takeo

Fusion Engineering and Design, 75-79, p.859 - 863, 2005/11

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

The Fusion Neutronics Source (FNS) of JAERI currently carries out the measurements of energetic charged particles emitted from fusion materials irradiated with a well-collimated 14 MeV neutron beam. At the beginning, the double differential cross section beryllium was measured. We have measured proton, triton and a particle emitted from a beryllium sample of 100 $$mu$$m in thickness.The a particle and triton were produced by $$^{9}$$Be(n,$$alpha$$)$$^{6}$$He, $$^{9}$$Be(n,2n)2$$alpha$$ and $$^{9}$$Be(n,t)$$^{7}$$Li reactions respectively. Measured total reaction rates from the counts of a particles and tritons were 2.7$$times$$10$$^{-24}$$ and 6$$times$$10$$^{-27}$$/atom/neutron, respectively, which were consistent with the calculated values from the nuclear data JENDL-3.2.

JAEA Reports

Program POD-P; A Computer code to calculate cross sections for neutron-induced preequilibrium nuclear reactions

Kunieda, Satoshi; Ichihara, Akira

JAERI-Data/Code 2005-005, 33 Pages, 2005/09

JAERI-Data-Code-2005-005.pdf:1.5MB

The computer code, POD-P, was developed to calculate energy spectra and angular distributions of emitted particles for the neutron-induced preequiliblium nuclear reactions. The energy-differential cross sections are computed with the classical one-component exciton model for the nucleon and composite-particle emissions. Along with this, the semi-empirical exciton models are also used for the composite-particle emissions. The double-differential cross sections are derived from those model calculations plus the angular-distribution systematics. The computational method and explanation of input parameters are given with some output examples.

Journal Articles

Simulations of an accelerator-based shielding experiment using the particle and heavy-ion transport code system PHITS

Sato, Tatsuhiko; Sihver, L.*; Iwase, Hiroshi*; Nakashima, Hiroshi; Niita, Koji*

Advances in Space Research, 35(2), p.208 - 213, 2005/06

 Times Cited Count:24 Percentile:83.12(Engineering, Aerospace)

In order to estimate the biological effects of HZE particles, an accurate knowledge of the physics of interaction of HZE particles is necessary. Since the heavy ion transport problem is a complex one, there is a need for both experimental and theoretical studies to develop accurate transport models. RIST and JAERI (Japan), GSI (Germany) and Chalmers (Sweden) are therefore currently developing and bench marking the General-Purpose Particle and Heavy-Ion Transport code System (PHITS). In this paper, we report simulations of an accelerator-based shielding experiment, in which a beam of 1 GeV/n Fe-ions has passed through thin slabs of polyethylene, Al, and Pb at an acceptance angle up to 4&ordm.

Journal Articles

JENDL photonuclear data file

Kishida, Norio*; Murata, Toru*; Asami, Tetsuo*; Kosako, Kazuaki*; Maki, Koichi*; Harada, Hideo*; Lee, Y.*; Chang, J.*; Chiba, Satoshi; Fukahori, Tokio

AIP Conference Proceedings 769, p.199 - 202, 2005/05

Nuclear data for photonuclear reactions are required in the field of shielding design of high-energy electron accelerators and high-energy $$gamma$$-ray therapy. The JENDL Photonuclear Data File was prepared by a working group on nuclear data evaluations for photonuclear reactions in Japanese Nuclear Data Committee. From a survey of many literatures, it is difficult to construct the photonuclear data file by using only measured data, since there are not sufficient experimental data. We were therefore evaluating with theoretical calculations based on statistical nuclear reaction models. The photonuclear cross sections that are to be contained in the file are as follows: photoabsorption cross sections, yield cross sections and DDX for neutrons, protons, deuterons, tritons, $$^{3}$$He-particles and alpha-particles, and isotope production cross sections. For the actinide nuclides, photofission cross sections are also included. The maximum energy of incident photons is 140 MeV and stored are the photonuclear data for 68 nuclides from $$^{2}$$H to $$^{237}$$Np.

JAEA Reports

Proceedings of 2004 Symposium on Nuclear Data; November 11-12, 2004, JAERI, Tokai, Japan

Tahara, Yoshihisa*; Fukahori, Tokio

JAERI-Conf 2005-003, 254 Pages, 2005/03

JAERI-Conf-2005-003.pdf:32.21MB

The 2004 Symposium on Nuclear Data was held at Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI), on 11th and 12th of November 2004. Japanese Nuclear Data Committee and Nuclear Data Center, JAERI organized this symposium. In the oral sessions, presented were 19 papers on topics of nuclear data for LWR and nuclear fuel cycle, nuclear data for ADS development, experiences from use of JENDL-3.3 and requests to JENDL-4, recent cross section measurements, nuclear data for life and material sciences, and nuclear data needs and activities in the World. In the poster session, presented were 21 papers concerning experiments, evaluations, benchmark tests, applications and so on. Those presented papers are compiled in the proceedings.

JAEA Reports

JAERI Tandem annual report 2003; April 1, 2003 - March 31, 2004

Department of Materials Science

JAERI-Review 2004-027, 131 Pages, 2004/12

JAERI-Review-2004-027.pdf:17.03MB

This report is research activities using Tandem Accelerator in Tokai during April 1st in 2003 to March 31st in 2004, and contains 42 reports of 7sections of (1) operation and developments of tandem accelerator, (2) nuclear structure, (3) nuclear reactions, (4) nuclear chemistry, (5) nuclear theory, (6) atomic physics and solid state physics, (7) radiation effect of materials, and also contains of publication lists, personnel for related activities and the cooperation research program between JAERI and universities, national research organizations and so on.

Journal Articles

Intelligible seminor on fusion reactors, 1; Introduction to fusion reactors

Ueda, Yoshio*; Inoue, Takashi; Kurihara, Kenichi

Nihon Genshiryoku Gakkai-Shi, 46(12), p.845 - 852, 2004/12

no abstracts in English

Journal Articles

Measurement of depth distributions of $$^{3}$$H and $$^{14}$$C induced in concrete shielding of an electron accelerator facility

Endo, Akira; Harada, Yasunori; Kawasaki, Katsuya; Kikuchi, Masamitsu

Applied Radiation and Isotopes, 60(6), p.955 - 958, 2004/06

 Times Cited Count:6 Percentile:42.06(Chemistry, Inorganic & Nuclear)

no abstracts in English

JAEA Reports

Proceedings of the 2003 Symposium on Nuclear Data; November 27-28, 2003, JAERI, Tokai, Japan

Osawa, Takaaki*; Fukahori, Tokio

JAERI-Conf 2004-005, 262 Pages, 2004/04

JAERI-Conf-2004-005.pdf:15.24MB

The 2003 Symposium on Nuclear Data was held at Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI), on 27th and 28th of November 2003. Japanese Nuclear Data Committee and Nuclear Data Center, JAERI organized this symposium. In the oral sessions, presented were 18 papers on topics of ADS development and nuclear data for transmutation, nuclear data needs for next generation reactors and future JENDL plan, frontier of nuclear physics studies and nuclear data measurements, advanced science study and nuclear data, nuclear data needs and activities in Asian region, future of nuclear data study and other subjects. In the poster session, presented were 26 papers concerning experiments, evaluations, benchmark tests and so on. Those presented papers are compiled in the proceedings.

JAEA Reports

JAERI Tandem annual report 2002; April 1, 2002 - March 31, 2003

Department of Materials Science

JAERI-Review 2003-028, 173 Pages, 2003/11

JAERI-Review-2003-028.pdf:8.28MB

This annual report describes research activities which have been performed with the JAERI tandem accelerator from April 1, 2002 to March 31, 2003. Summary reports of 54 papers, and lists of publication, personnel and cooperative research with universities are contained.

88 (Records 1-20 displayed on this page)