Research and development of in-situ measurement for radiation distribution of waterbed

Sanada, Yukihisa; Takamura, Yoshihide; Urabe, Yoshimi; Tsuchida, Kiyofumi; Nishizawa, Yukiyasu; Yamada, Tsutomu; Sato, Yoshiharu; Hirayama, Hirokatsu; Nishihara, Katsuya; Imura, Mitsuo; et al.

JAEA-Research 2014-005, 67 Pages, 2014/05

JAEA-Research-2014-005.pdf:52.68MB

Distribution of radiocesium existing on the waterbed such as lake or pond was concerned about at the present that passed for two years by an accident. Here, the direct measurement technique of the radiocesium concentration (in-situ measurement technique) was developed. This method was used an plastic scintillation detector (p-Scanner). This detector carried out quick measurement of a large area. In addition, the count-rate of p-Scanner was converted to the radiocesium concentration (Ba/kg-wet) by comparative measurement of -ray spectrometer. We applied the technique to the agricultural pond in Fukushima and made a map of distribution of radiocesium concentration.

Computer Simulation of Transport and Maintenance Methods in a Pyrochemical Reprocessing Plant Design

Yonezawa, Shigeaki;

Proceedings of 11th International Conference on Nuclear Engineering (ICONE-11) (CD-ROM), P. 36536, 2003/00

None

Simulation of a dry reprocessing plant operation

; ; Yoshiuji, Takahiro*

JNC TN9400 2002-040, 49 Pages, 2002/07

JNC-TN9400-2002-040.pdf:3.39MB

Operations of a dry reprocessing plant are characterized by batch processing with remote-control material handling machines, so plant -wise simulation of their mechanical actions is required to evaluate the overall performance of the plant. Therefore a simulator has been developed using virtual engineering techniques. The results performed in JFY 2001 are as follows: (1)Construction of an operation simulator of a dry-reprocessing plant design. An operation simulator was developed based on the preliminarily conceptual design of the oxide-electrowinning reprocessing plant made at the phase one of the Feasibility Study on Commercialized Fast Reactor Cycle Systems. The simulator is able to correspond changes of the plant design in future. (2)Evaluation of the oxide-electrowinning reprocessing plant design Simulation was performed using the simulator of the preliminarily conceptual design of the oxide-electrowinning reprocessing plant. The results show that the capacity of the plant will be much lower than the designed one (50tHM/y) due to the speed of material handling machines. The results of the parametric survey of gripping and fixing time also show that the plant capacity can attain 94% of the required capacity even if the gripping and the fixing time decrease to zero. This indicates that only increasing the speed is not enough to dissolve the problem.

The development of mass balance estimation code; The development and the analyzed example with object type code(I)

;

JNC TN9400 2000-034, 48 Pages, 2000/03

JNC-TN9400-2000-034.pdf:1.56MB

The study and the development to put FBR (Fast Breeder Reactor) to practical use have been doing. So many kinds of technologies are investigated to construct nuclear fuel recycle received to the society. The most important aim of reprocessing has been to extract U and Pu from spent fuels effectively, but, now, the demands for reprocessing are many kinds on nuclear fuel recycle system's construction. These need to be accepted sufficiently. The system that consists of electrolysis, extraction, with molten salt and melting metal, volatilization and condensation using the difference of vapor pressure is suggested, because, differently from LWR (Light Water Reactor), FBR can use the low decontamination factor's fuel. When the engineering scale plant is designed, the dry reprocessing has unsolved problems(ex. process flow) because of less demonstrative scale plants of the dry reprocessing than ones of the wet reprocessing. So the analysis and the estimation of mass balance that is most fundamental in the dry reprocessing system's design need to keep up with the system's alteration (to add new processes etc.) flexibly. This study aim is to develop the mass balance estimation code of dry reprocessing that satisfies the demand mentioned above.

Designstudy on advanced nuclear fuel recycle system; Conceptual design study of recycle system using molten salt

; Kakehi, Isao; Moro, Satoshi; ; ; ;

JNC TN9400 98-003, 422 Pages, 1998/10

JNC-TN9400-98-003.pdf:21.36MB

Advanced recycle system engineering group of OEC has being carried out a design study of the advanced nuclear fuel recycle system using molten salt (electro-metallurgical process). This system is aiming for improvements of fuel cycle economy and reduction of environmental burden (MA recycles, Mimmum of radioactive waste disposal), and also improvement of safety and nuclear non-proliferation. This report describes results of the design study that has been continued since December 1996. (1)A design concept of the advanced nuclear fuel recycle system, that is a module type recycle system of pyrochemical reprocessing and fuel re-fabrication was studied. The module system has advantage in balance of Pu recycle where modules are constructed in coincidence with the construction plan of nuclear power plants, and also has flexibility for technology progress. A demonstration system, minimum size of the above module, was studied. This system has capacity of 10 tHM/y and is able to demonstrate recycle technology of MOX fuel, metal fuel and nitride fuel. (2)Each process of the system, which are pyrochemical electrorefining system, cathode processor, de-cladding system, waste disposal system, etc., were studied. In this study, capacity of an electrorefiner was discussed, and vitrification experiment of molten salt using lead-boric acid glass was conducted. (3)A hot cell system and material handling system of the demonstration system was studied. A robot driven by linear motor was studied for the handling system, and an arrangement plan of the cell system was made. Criticality analysis in the cell system and investigation of material accountancy system of the recycle plant were also made. This design study will be continued in coincidence with design study of reactor and fuel, aiming to establish the concept of FBR recycle system.

Desgin study of advanced nuclear fuel recycle system; Conceptual study of recycle system using molten salt

Kakehi, Isao; ; ; ; ; Kajitani, Yukio;

PNC TN9410 97-015, 382 Pages, 1996/12

PNC-TN9410-97-015.pdf:12.32MB

For the purpose of developing the future nuclear fuel recycle system, the design study of the advanced nuclear fuel recycle system is being conducted. This report describes intermediate accomplishments in the conceptual system study of the advanced nuclear fuel recycle system. Fundamental concepts of this system is the recycle system using molten salt which intend to break through the conventional concepts of purex and pellet fuel system. Contents of studies in this period are as follows, (1)feasibility study of the process by Cd-cathode for nitride fuel (2)application study for the molten salt of low melting point (AlCl+organic salt)(3)research for decladding (advantage of decladding by heat treatment)(4)behavior of FPs in electrorefinning (behavior of iodine and volatile FP chlorides, FPs behavior in chlorination) (5)criticaliy analysis in electrorefiner (6)drawing of off-gas flow diagram (7)drawing of process machinery concept (cathode processor, vibration packing) (8)evaluation for the amounts of the high level radioactive wastes (9)quality of the recycle fuels (FPs contamination of recycle fuel) (10)conceptual study of in-cell handling system (11)meaning of the advanced nuclear fuelrecycle system. The conceptual system study will be completed in describing concepts of the system and discussing issues for the developments.