Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 131

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

Development of a handy criticality analysis tool for fuel debris

Tada, Kenichi

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 4 Pages, 2019/05

The decommissioning of Fukushima Daiichi Nuclear Power Plant accident is one of the most important issues in Japan. The criticality safety of fuel debris is imperative to prevent exposure of workers. The investigating criticality monitoring system cannot detect the criticality of fuel debris quickly. The estimation of criticality of fuel debris is required for the fuel debris retrieval. Though the expert knowledge of reactor physics is necessary to estimate the criticality of fuel debris, many people who make a plan of fuel debris retrieval may not know well about criticality analysis. We developed a handy criticality analysis tool HAND to quickly estimate the criticality of fuel debris without expert knowledge of reactor physics. Since the input data of HAND is so simple and users can intuitively understand the calculation results, this tool is expected to be the effective tool to estimate the criticality of fuel debris.

Journal Articles

Analysis of used BWR fuel assay data with the integrated burnup code system SWAT4.0

Tada, Kenichi; Kikuchi, Takeo*; Sakino, Takao; Suyama, Kenya

Journal of Nuclear Science and Technology, 55(2), p.138 - 150, 2018/02

 Percentile:100(Nuclear Science & Technology)

The criticality safety of the fuel debris in Fukushima Daiichi Nuclear Power Plant is one of the most important issues and the adoption of the burnup credit is desired for the criticality analysis. The assay data of used nuclear fuel irradiated in 2F2 is evaluated to validate SWAT4.0 for BWR fuel burnup problem. The calculation results revealed that number density of many heavy nuclides and FPs showed good agreement with the experimental data except for $$^{235}$$U, $$^{237}$$Np, $$^{238}$$Pu and Sm isotopes. The cause of the difference is assumption of the initial number density and void ratio and overestimation of the capture cross section of $$^{237}$$Np. The C/E-1 values do not depend on the types of fuel rods (UO$$_{2}$$ or UO$$_{2}$$-Gd$$_{2}$$O$$_{3}$$) and it is similar to that for the PWR fuel. These results indicate that SWAT4.0 appropriately analyzes the isotopic composition of the BWR fuel and it has sufficient accuracy to be adopted in the burnup credit evaluation of the fuel debris.

Journal Articles

Accumulation of gadolinium isotopes in used nuclear fuel

Suyama, Kenya; Kashima, Takao

Proceedings of International Conference on Nuclear Criticality Safety (ICNC 2015) (DVD-ROM), p.273 - 282, 2015/09

In the technical development of the criticality safety control of the fuel debris of Fukushima accident in Japan, there have been a discussion on a possibility of adopting BUC with FP. The Expert Group on Burnup Credit Criticality Safety (EGBUC) under the Working Party on Nuclear Criticality Safety (WPNCS) in OECD/NEA Nuclear Science Committee had carried out an international burnup calculation benchmark "Phase-IIIB" and "Phase-IIIC" for BWR fuel assemblies. In these benchmarks the difference of the calculation results of $$^{155}$$Gd among the participants obtained keen interests because it showed rather larger difference among the participants. Authors has been carried out additional analyses on the accumulation of the gadolinium isotopes in the used nuclear fuel during the burnup. Without cooling time, the assembly-averaged amount of $$^{155}$$Gd against the burnup value depends on the burnout property of gadolinium in the burnable poison rods. However, after few year cooling time, $$^{155}$$Gd increase drastically by the decay of $$^{155}$$Eu. In this case, the amount of gadolinium isotopes in the burnable poison rods has less importance. It means that the adopted parameters and data concerning the $$^{155}$$Eu generation have much more importance than the burnup treatment of the burnable poison rods for better prediction of $$^{155}$$Gd.

JAEA Reports

Criticality safety assessment by assuming spent fuel burnup distribution; Examination of various methods for setting burnup, 1 (Contract research)

Nomura, Yasushi*; Okuno, Hiroshi; Miyoshi, Yoshinori

JAERI-Tech 2004-030, 64 Pages, 2004/03

JAERI-Tech-2004-030.pdf:4.59MB

no abstracts in English

JAEA Reports

Proceedings of the 7th International Conference on Nuclear Criticality Safety ICNC2003; Challenges in the Pursuit of Global Nuclear Criticality Safety, October 20-24, 2003 Techno Community Square Ricotti, Tokai, Ibaraki, Japan

ICNC2003 Technical Program Committee

JAERI-Conf 2003-019, 896 Pages, 2003/10

JAERI-Conf-2003-019-Part1.pdf:39.68MB
JAERI-Conf-2003-019-Part2.pdf:44.42MB

These proceedings contain technical papers at the 7th International Conference on Nuclear Criticality Safety ICNC2003 held on 20-24 October 2003, in Tokai, Ibaraki, Japan, following ICNC'99 in Versailles, France. The theme of this conference is "Challenges in the Pursuit of Global Nuclear Criticality Safety". These proceedings represent the current status of nuclear criticality safety research throughout the world.

JAEA Reports

Proceedings of the 6th NUCEF Seminar; February 20, 2003, JAERI, Tokai, Japan

6th NUCEF Seminar Working Group

JAERI-Conf 2003-018, 132 Pages, 2003/10

JAERI-Conf-2003-018.pdf:10.41MB

no abstracts in English

Journal Articles

Present Status of Monte Carlo Seminar for Sub-criticality Safety Analysis in Japan

Sakurai, Kiyoshi; Nojiri, Ichiro*

JAERI-Conf 2003-019, p.855 - 857, 2003/10

This paper provides overview of sub-criticality safety analysis seminar (July 2000-July 2003, JAERI, total 40 engineers from universities, research institutes and enterprises) for nuclear fuel cycle facility with the Monte Carlo method in Japan. MCNP-4C2 system (MS-DOS version) was installed in each note-type personal computer. Fundamental theory of reactor physics and Monte Carlo simulation including MCNP-4C manual was lectured. Effective neutron multiplication factor and neutron spectrum were calculated for JCO deposit tank, JNC uranium solution storage tank, JNC plutonium solution storage tank and JAERI TCA core. In the seminar, methodology of safety management for nuclear fuel cycle facility was discussed in order to prevent criticality accident.

Journal Articles

History and understanding of the double contingency principle

Komuro, Yuichi

Nippon Genshiryoku Gakkai-Shi, 45(4), p.265 - 269, 2003/04

no abstracts in English

JAEA Reports

Derivation of correction factor to be applied for calculated results of BWR fuel isotopic composition by ORIGEN2.1 code

Nomura, Yasushi; Mochizuki, Hiroki*

JAERI-Tech 2002-068, 131 Pages, 2002/11

JAERI-Tech-2002-068.pdf:5.59MB

no abstracts in English

Journal Articles

Mechanisms of positive temperature reactivity coefficients of dilute plutonium solutions

Yamamoto, Toshihiro; Miyoshi, Yoshinori

Nuclear Science and Engineering, 142(3), p.305 - 314, 2002/11

 Times Cited Count:1 Percentile:88.46(Nuclear Science & Technology)

Mechanisms of a positive temperature reactivity coefficient that occurs in a dilute plutonium solution are investigated based on the perturbation theory and the four-factor formula. The temperature coefficient of a solution fuel is positive if the adjoint flux or ηf between 0.05eV and 0.2eV increases with neutron energy. As compared to Pu-239, Pu-241 has a tendency to make the temperature coefficient of a plutonium solution. As Pu-241 in a plutonium solution decays into Am-241 with time, the temperature coefficient becomes more positive. Since the capture cross sections of most neutron absorbers such as boron and gadolinium decreases with increasing neutron energy, soluble absorbers make the temperature coefficient positive for higher concentration plutonium solution. Cadmium and samarium solved in a dilute plutonium solution exceptionally can keep the temperature coefficient. A fixed neutron absorber generally makes the temperature coefficient negative regardless of the property of absorber materials.

Journal Articles

Outline of simulation code fact for analysis of ventilation system on criticality accident

Tsubata, Yasuhiro; Tashiro, Shinsuke; Koike, Tadao; Abe, Hitoshi*; Watanabe, Koji; Uchiyama, Gunzo

Transactions of the American Nuclear Society, 87, p.60 - 61, 2002/11

no abstracts in English

JAEA Reports

Proceedings of the 5th NUCEF Seminar; February 27, 2001, JAERI, Tokai, Japan

5th NUCEF Seminar Working Group

JAERI-Conf 2001-015, 92 Pages, 2001/12

JAERI-Conf-2001-015.pdf:13.1MB

no abstracts in English

Journal Articles

The 1th and 2th Seminar on Subcriticality Safety with Monte Carlo Method on Nuclear Fuel Cycle Facility

Sakurai, Kiyoshi

Nippon Genshiryoku Gakkai-Shi, 43(11), P. 1113, 2001/11

no abstracts in English

Journal Articles

Research activities on advanced nuclear fuel cycle in NUCEF

Suzuki, Yasufumi; Dojiri, Shigeru; Ono, Akio; Maeda, Atsushi; Sugikawa, Susumu

Proceedings of International Conference on Back-End of the Fuel Cycle: From Research to Solutions (GLOBAL 2001) (CD-ROM), 7 Pages, 2001/09

no abstracts in English

JAEA Reports

Journal Articles

What is Japanese for English "double contingency principle"?

Komuro, Yuichi

Nippon Genshiryoku Gakkai-Shi, 43(6), p.580 - 581, 2001/06

no abstracts in English

Journal Articles

Education program for criticality safety with Monte Carlo method

Sakurai, Kiyoshi; Ueki, Kotaro*; Naito, Yoshitaka*

Nippon Genshiryoku Gakkai-Shi, 43(3), p.219 - 220, 2001/03

no abstracts in English

JAEA Reports

None

JNC-TN8200 2000-006, 443 Pages, 2000/07

JNC-TN8200-2000-006.pdf:41.45MB

None

JAEA Reports

Proceedings of the 4th NUCEF Seminar; 18 Feb. 2000, JAERI Tokai, Japan

4th NUCEF Seminar Working Group

JAERI-Conf 2000-012, 52 Pages, 2000/07

JAERI-Conf-2000-012.pdf:5.47MB

no abstracts in English

131 (Records 1-20 displayed on this page)