Experiment of incineration for Trans-Uranic (TRU) wastes containing chlorides

Yamashita, Kiyoto; Yokoyama, Aya*; Takagai, Yoshitaka*; Maki, Shota; Yokosuka, Kazuhiro; Fukui, Masahiro; Iemura, Keisuke

JAEA-Technology 2022-020, 106 Pages, 2022/10

JAEA-Technology-2022-020.pdf:4.77MB

Radioactive solid wastes generated by Fukushima Daiichi Nuclear Power Station disaster may contain high levels of salt from the tsunami and seawater deliberately released into the area. It is assumed that polyvinyl chloride (PVC) products may be used for decommissioning work and for containment of radioactive wastes in the future. Among the method of handling them, incineration is one method that needs to be investigated as it is good method for reduction and stabilization of wastes. But in order to dispose of Trans-Uranic (TRU) solid waste containing chlorides, it is necessary to select the structure and materials of the facility based on the information such as the movement of nuclides and chlorides in the waste gas treating system and the corrosion of equipment due to chlorides. Therefore, we decided to get various data necessary to design a study of the incineration facilities. And we decided to examine the transfer behavior of chlorides to the waste gas treatment system, the corrosion-resistance of materials in the incineration facilities, and the distribution survey of plutonium in them obtained using the Plutonium-contaminated Waste Treatment Facility (PWTF), Nuclear Fuel Cycle Engineering Laboratories, which is a unique incinerating facility in Japan. This report describes the transfer behavior of chlorides in the waste gas treatment system, the evaluation of corrosion-resistance materials and the distribution survey of plutonium in the incineration facilities obtained by these tests using the Plutonium-contaminated Waste Treatment Facility, Nuclear Fuel Cycle Engineering Laboratories.

Applicability study of nuclear graphite material IG-430 to VHTR

Osaki, Hirotaka; Shimazaki, Yosuke; Sumita, Junya; Shibata, Taiju; Konishi, Takashi; Ishihara, Masahiro

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 8 Pages, 2015/05

For the design on the VHTR graphite components, it is desirable to employ graphite material with higher strength. IG-430 graphite has been developed as an advanced candidate for VHTR. However, the new developed IG-430 does not have enough databases for the design of HTGR. In this paper, the compressive strength (Cs) of IG-430, one of important strengths for design data, is statistically evaluated. The component reliability is evaluated based on the safety factors defined by the graphite design code, and the applicability as the VHTR graphite material is discussed. It was found that IG-430 has higher strength (about 11%) and lower standard deviation (about 27%) than IG-110 which is one of traditional graphites used for HTGR, because the crack in IG-430 would not easy to propagate rather than IG-110. Since fracture probability for IG-430 is low, the higher reliability of core-component will be achieved using IG-430. It is expected that IG-430 is applicable for VHTR graphite material.

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.

Application of infrared thermography to nondestructive evaluation of nuclear structures and components

Ishii, Toshimitsu; Ooka, Norikazu; Naka, Michihiro; Kanaya, Kunio; Saito, Junichi; Okamoto, Yoshizo*

Proceedings of 6th Far-East Conference on Nondestructive Testing (FENDT '02), p.273 - 278, 2002/00

no abstracts in English

Biaxial strength and fracture criterion for HTGR graphites

Eto, Motokuni; Ishiyama, Shintaro; T.D.Burchell*; G.T.Yahr*

Journal of Nuclear Science and Technology, 34(5), p.476 - 483, 1997/05

https://doi.org/10.3327/jnst.34.476

no abstracts in English

Development of probabilistic methodology for evaluating seismic base isolation of nuclear components and verification test program

Shibata, Katsuyuki; ; *

Proc. of 7th German-Japan Joint Seminar on Research in Structural Strength and NDE-Problems, 12 Pages, 1997/00

no abstracts in English

Evaluation of the Oxidation Behavior and Strength of the Graphite Components in the VHTR, (I); Normal Operation Condition

; ; ;

JAERI-M 87-056, 49 Pages, 1987/03

JAERI-M-87-056.pdf:1.11MB

no abstracts in English

Conceptual Design Nuclear Power Plant Database System

*; ;

JAERI-M 84-051, 40 Pages, 1984/03

JAERI-M-84-051.pdf:1.09MB

no abstracts in English

About the situation of decontamination and the future

Yamashita, Takuya

no journal, , 

JAEA has been conducting decontamination simulations and calculating the future air dose rates for the purpose of providing information to the government and local governments that are in the process of reconstruction. The restoration support system for environment "RESET" is used for decontamination simulation, and "two component model of air dose rate attenuation" is used for prediction of future air dose rate after decontamination. Since the "two-component model of air dose rate attenuation" has not been sufficiently confirmed for the measurement data after decontamination, the applicability to the area after decontamination was verified. Since the prediction by the two-component model has good agreement with the measured air dose rate after the decontamination model demonstration project conducted by the Ministry of the Environment and the variation of the parameters, it is judged that there is no problem in applying to prediction.

Spectral analysis by a neural network using processed data whose dimensions have been reduced by principal component analysis as learning data

Oba, Masaki

no journal, , 

Dimension reduction was performed using PCA on 462 types of training data obtained by processing GdO, TiO, ZrOdata. After learning, the content rates of elements were analyzed using 62 types of data from actual samples as test data. Similar to last time, create a calibration curve of the true value and analytical value of the actual sample and analyze the content ratio. The neural network used this time had a configuration of input layer, middle layer (2 layers), and output layer, and the middle layer used 2 layers with 100 nodes each. As a result of PCA on the training data, we were able to significantly reduce the 7944 dimensions (pixels) of the training data to 5 dimensions. As a result of training using this and analyzing test data, the difference from the true value was approximately 10%, which was almost the same as the previous value.