R&D activities of tritium technologies on Broader Approach in Phase 2-2

Isobe, Kanetsugu; Kawamura, Yoshinori; Iwai, Yasunori; Oyaizu, Makoto; Nakamura, Hirofumi; Suzuki, Takumi; Yamada, Masayuki; Edao, Yuki; Kurata, Rie; Hayashi, Takumi; et al.

Fusion Engineering and Design, 98-99, p.1792 - 1795, 2015/10

https://doi.org/10.1016/j.fusengdes.2015.06.075

Activities on Broader Approach (BA) were started in 2007 on the basis of the Agreement between the Government of Japan and the EURATOM. The period of BA activities consist of Phase1 and Phase2 dividing into Phase 2-1 (2010-2011), Phase 2-2 (2012-2013) and Phase 2-3 (2014-2016). Tritium technology was chosen as one of important R&D issues to develop DEMO plant. R&D activities of tritium technology on BA consist of four tasks. Task-1 is to prepare and maintain the tritium handling facility in Rokkasho BA site in Japan. Task 2, 3 and 4 are main R&D activities for tritium and these are focused on: Task-2) Development of tritium accountancy technology, Task-3) Development of basic tritium safety research, Task-4) Tritium durability test. R&D activities of tritium technology in Phase 2-2 were underway successfully and closed in 2013.

Evaluation of tritium release properties of advanced tritium breeders

Hoshino, Tsuyoshi; Ochiai, Kentaro; Edao, Yuki; Kawamura, Yoshinori

Fusion Science and Technology, 67(2), p.386 - 389, 2015/03

https://doi.org/10.13182/FST14-T35

Demonstration power reactors (DEMOs) require advanced tritium breeders that have high stability at high temperatures. Therefore, the pebble fabrication of LiTiO with excess Li (LiTiO) as an advanced tritium breeder was carried out. In this study, a preliminary examination of the tritium release properties of advanced tritium breeders was performed. DT neutron irradiation experiments were performed at the fusion neutronics source (FNS) facility in JAEA. The LiTiO pebbles exhibited good tritium release properties similar to the LiTiO pebbles. In particular, the released amount of HT gas for easier tritium handling was higher than that of HTO water.

Measurement of tritium penetration through concrete material covered by various paints coating

Edao, Yuki; Kawamura, Yoshinori; Kurata, Rie; Fukada, Satoshi*; Takeishi, Toshiharu*; Hayashi, Takumi; Yamanishi, Toshihiko

Fusion Science and Technology, 67(2), p.320 - 323, 2015/03

https://doi.org/10.13182/FST14-T20

The present study aims at obtaining fundamental knowledge for tritium transfer behavior and interaction between tritium and paint coated on concrete walls. The amounts of tritium penetration and release in cement paste with epoxy and urethane paint coatings were measured. The tritium penetration amounts were increased with the HTO exposure time. Time to achieve each saturate tritium value was more than 60 days for cement paste coated with epoxy paint and with urethane paint, while cement paste without paint took 2 days to achieve it. Tritium penetration rates were estimated by an analysis of diffusion model. Although their paint coatings were effective for reduction of tritium penetration through the cement paste exposed to HTO for a short period, the amount of tritium trapped in the paints became large for a long time. This work has been performed under the collaboration research between JAEA and Kyushu University.

Penetration of tritiated water vapor through hydrophobic paints for concrete materials

Edao, Yuki; Kawamura, Yoshinori; Yamanishi, Toshihiko; Fukada, Satoshi*

Fusion Engineering and Design, 89(9-10), p.2062 - 2065, 2014/10

https://doi.org/10.1016/j.fusengdes.2014.02.059

Tritium transfer behavior through hydrophobic paints, epoxy resin and acrylic-silicon resin, was investigated experimentally. The authors measured the amount of tritium permeated through the paint membranes which exposed in HTO atmosphere of 2100 Bq/cm. The most of tritium permeated through the paints in the form of HTO at room temperature. Tritium permeation through the acrylic-silicon paint was explained a linear sorption/release model and that through the epoxy paint was suggested to be controlled by a one-dimensional diffusion model. While effective diffusivity was 1.0101.810 m/s at 21C26C for epoxy membrane, the diffusivity was found to be hundreds times larger than that for cement-paste coated with epoxy paint. Hence, tritium diffusivity through interface between cement-paste and the epoxy paint was considered to be most effective in the overall tritium transfer process. Tritium transfer behavior in the interface is important to explain the mechanism of tritium transfer behavior in concrete walls.

Hydrogen and water vapor adsorption properties on cation-exchanged mordenite for use to a tritium recovery system

Kawamura, Yoshinori; Edao, Yuki; Iwai, Yasunori; Hayashi, Takumi; Yamanishi, Toshihiko

Fusion Engineering and Design, 89(7-8), p.1539 - 1543, 2014/10

https://doi.org/10.1016/j.fusengdes.2014.01.064

Tritium recovery system using adsorption or catalytic isotope exchange has already been proposed for a solid breeding blanket system of a nuclear fusion reactor. Synthetic zeolite is often used as an adsorbent or a substrate of chemical exchange catalyst. And, it is well known that its properties are changed easily by exchanging their cations. So, in this work, adsorption capacities of hydrogen isotope and water vapor on cation-exchanged mordenite with transition metal ion were investigated. Ag ion-exchanged mordenite (Ag-MOR) has indicated considerably large hydrogen adsorption capacity in lower pressure range at 77 K. And, adsorption capacity of water vapor did not so vary with exchaned cation in comparison with hydrogen adsorption. The discussion from the viewpoint of adsorption rate is still remaining, but more compact cryosorption column for tritium recovery system is possible to design if Ag-MOR is adopted.

Engineering validation and engineering design of lithium target facility in IFMIF/EVEDA project

Wakai, Eiichi; Kondo, Hiroo; Kanemura, Takuji; Furukawa, Tomohiro; Hirakawa, Yasushi; Watanabe, Kazuyoshi; Ida, Mizuho*; Ito, Yuzuru; Niitsuma, Shigeto; Edao, Yuki; et al.

Fusion Science and Technology, 66(1), p.46 - 56, 2014/07

https://doi.org/10.13182/FST13-770

Characteristic of tritium release from LiTiO under D-T neutron irradiation

Edao, Yuki; Kawamura, Yoshinori; Ochiai, Kentaro; Hoshino, Tsuyoshi; Takakura, Kosuke; Ota, Masayuki; Iwai, Yasunori; Yamanishi, Toshihiko; Konno, Chikara

JAEA-Research 2012-040, 15 Pages, 2013/02

JAEA-Research-2012-040.pdf:1.8MB

Tritium generation and recovery studies on LiTiO as a solid breeding material under neutron irradiation carried out in the Fusion Neutron Source (FNS) facility. A capsule with LiTiO packed bed was put in a system which simulated an actual blanket system which built in beryllium blocks and lithium titanate ones. Estimated values of the amount of tritium generation by a numerical calculation agreed closely with experimental values. The capsule was heated up to 300C, and helium, helium with water vapor, hydrogen or hydrogen/water vapor were selected as purge gas. In the case of purge by helium added water vapor, the ratio of HTO to total tritium release was 98%. In helium with hydrogen/water vapor purge, the ratio of HTO to total tritium release was 80%, which was confirmed that HTO released by isotope exchange reaction between water vapor and tritium. In helium with hydrogen purge, the ratio of HT to total tritium release was 6070%, which was shown that HT released by isotope exchange reaction between hydrogen gas and tritium. HTO released by water generation reaction between hydrogen in purge gas and oxygen in LiTiO although water vapor was not added in purge gas. The ratio of HTO release seemed to be small under the deoxidized condition of the LiTiO surface. Tritium release behavior in the LiTiO depended on the composition of purge gas, and its chemical form was affected by the surface conditions of LiTiO.

Adsorption rate of hydrogen isotopes on K-mordenite

Kawamura, Yoshinori; Edao, Yuki; Yamanishi, Toshihiko

no journal, , 

To develop an adsorbent that is suitable for a separation column of gas chromatograph for hydrogen isotope analysis, the samples of which cations were exchanged with other cations have been prepared and their hydrogen isotope adsorption behavior is being investigated. Then, it has been shown experimentally that mordenite-type zeolite of which cation has been exchanged with K (K-MOR) has small adsorption capacity. So, breakthrough curves of H (or D) adsorption on K-MOR have been observed and their mass transfer coefficients have been estimated. The pore diffusion of hydrogen is the rate-controlling step of hydrogen adsorption. The effective diffusivity of hydrogen in K-MOR is smaller than that in Ca-MOR. This is probably caused by the small pore size of K-MOR.

Tritium recovery experiment from simulating solid breeder blanket with DT neutron irradiation, 3

Ochiai, Kentaro; Edao, Yuki; Kawamura, Yoshinori; Hoshino, Tsuyoshi; Takakura, Kosuke; Konno, Chikara

no journal, , 

no abstracts in English

Effect of paint for tritium penetration through concrete walls

Edao, Yuki; Kawamura, Yoshinori; Hayashi, Takumi; Fukada, Satoshi*

no journal, , 

It is important to understand effect of paints coated on concrete walls in tritium penetration through the concrete walls in order to evaluate contamination of the concrete walls in the accidental case of tritium release. In the present study, behavior of tritium vapor permeation through various pains such as epoxy, urethane and silicon resin is measured, the permeation rates are obtained, and results of our investigation for behavior of tritium transfer between concrete materials and paints will be reported.