Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell

Sonoda, Tetsu*; Katayama, Ichiro*; Wada, Michiharu*; Iimura, Hideki; Sonnenschein, V.*; Iimura, Shun*; Takamine, Aiko*; Rosenbusch, M.*; Kojima, Takao*; Ahn, D. S.*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2019(11), p.113D02_1 - 113D02_12, 2019/11

AA2019-0315.pdf:1.37MB

https://doi.org/10.1093/ptep/ptz120

An in-flight separator, BigRIPS, at RIBF in RIKEN provides each experiment with specific nuclides separated from many nuclides produced by projectile fragmentation or in-flight fission. In this process, nuclides other than separated ones are discarded on the slits in BigRIPS, although they include many nuclides interested from the view point of nuclear structure. In order to extract these nuclides for parasitic experiments, we are developing a method using laser ion-source (PALIS). A test experiment with Se beam from RIBF has been performed by using a gas cell set in BigRIPS. Unstable nuclides around Se were stopped in the gas cell in accordance with a calculation using LISE code. The stopping efficiency has been estimated to be about 30%. As a next step, we will establish the technique for extracting reaction products from the gas cell.

Conceptual design of the SlimCS fusion DEMO reactor

Tobita, Kenji; Nishio, Satoshi*; Enoeda, Mikio; Nakamura, Hirofumi; Hayashi, Takumi; Asakura, Nobuyuki; Uto, Hiroyasu; Tanigawa, Hiroyasu; Nishitani, Takeo; Isono, Takaaki; et al.

JAEA-Research 2010-019, 194 Pages, 2010/08

JAEA-Research-2010-019-01.pdf:48.47MB
JAEA-Research-2010-019-02.pdf:19.4MB

This report describes the results of the conceptual design study of the SlimCS fusion DEMO reactor aiming at demonstrating fusion power production in a plant scale and allowing to assess the economic prospects of a fusion power plant. The design study has focused on a compact and low aspect ratio tokamak reactor concept with a reduced-sized central solenoid, which is novel compared with previous tokamak reactor concept such as SSTR (Steady State Tokamak Reactor). The reactor has the main parameters of a major radius of 5.5 m, aspect ratio of 2.6, elongation of 2.0, normalized beta of 4.3, fusion out put of 2.95 GW and average neutron wall load of 3 MW/m. This report covers various aspects of design study including systemic design, physics design, torus configuration, blanket, superconducting magnet, maintenance and building, which were carried out increase the engineering feasibility of the concept.

Physics issues and simulation of the JT-60 SA divertor for large heat and particle handling

Asakura, Nobuyuki; Kawashima, Hisato; Shimizu, Katsuhiro; Sakurai, Shinji; Fujita, Takaaki; Takenaga, Hidenobu; Nakano, Tomohide; Kubo, Hirotaka; Higashijima, Satoru; Hayashi, Takao; et al.

Europhysics Conference Abstracts (CD-ROM), 31F, 4 Pages, 2007/00

http://epsppd.epfl.ch/Warsaw/html/a_index.htm

Divertor design for the JT-60 SA has been progressing in order to handle large heat flux during full pulse duration of 100 s. Divertor should be suitable for single null plasma experiments with the full power injection of 41 MW. The simulation results using 2D fluid (plasma) and Monte-Carlo (neutral) code are summarized. Lower single-null divertor is designed for ITER-like plasma configuration in order to study physics concept of the ITER divertor: control of the plasma detachment. Simulation results for various divertor geometries showed that the vertical target with V-shaped corner can produce plasma detachment near the outer strike-point for medium edge plasma density. It was also demonstrated that the divertor plasma became attached to move the outer strike point above the V-corner, suggesting that recover from sever detachment can be achieved by changing the plasma location. USN divertor will be designed for high- plasma experiments with the highest shaping plasma of S=6.

Nobel system for uranium recovery from seawater

Seko, Noriaki; Kasai, Noboru; Shimizu, Takao*; Tamada, Masao

Nihon Kaisui Gakkai-Shi, 59(5), p.316 - 319, 2005/10

http://joi.jlc.jst.go.jp/DN/JST.JSTAGE/swsj1965/34.316

Braid adsorbent having functional group of amidoxime is a promising material for the recovery of uranium dissolved in the seawater. This long braid adsorbent was made by polyethylene multi-fibers in which amidoxime groups were introduced by radiation-induced graft polymerization and subsequent chemical treatment. The braid adsorbent obtained was moored at the offing of Okinawa Island. The average U adsorption of the adsorbent became 1.5 g-U/kg-adsorbent for 30 d soaking. The mooring system for braid adsorbent has possibility which reduced the cost for the recovery of uranium from seawater. Annual product of 1200 tons of uranium needs 134 km of mooring area. In addition, there is 6000 km and more of suitable sea area for the collection of the uranium in the regions from Okinawa Islands to Tosa Bay in Japan.

Practical scale system for uranium recovery from seawater using braid type absorbent

Shimizu, Takao*; Tamada, Masao

Kaiyo Kaihatsu Rombunshu, 20, p.617 - 622, 2004/06

https://doi.org/10.2208/prooe.20.617

Recovery system of braid type adsorbent which stands straight with built-in float from sea bottom was proposed on the points of effective and economical view. The system scale for 1200 t/y recovery (demand for 6 atomic power plants) with braid type adsorbent was optimized by a model in which the efficiency of uranium adsorption was proportional to the uranium concentration surrounding the adsorbent. The recovery system of 2.67 millions adsorbents which were arranged with the distance of more than 60m intervals among the adsorbents could collect 1200t/y uranium. The system still collected 1000 t/y uranium when the interval distance decreased to 4 m. The area occupied by the adsorbents was 6.5 km square. The sea area on the coast of Japan was searched for recovery system of braid type adsorbent by considering the factors of the temperature, the depth, the fishery, and the territorial waters of Japan. The selected sea area was located form the South East Islands to the offing of Koch in the depth range from 100m to 200m, where the Japan Current flew.

Development of a Real-Time Environmental Radiation Dose Evaluation System for the Vicinity of a Nuclear Facility; A Study of a Real-Time Environmental Radiation Dose Evaluation System

Takeyasu, Masanori; Takeishi, Minoru; Shimizu, Takehiko; Iida, Takao*

Hoken Butsuri, 39(4), p.382 - 390, 2004/00

https://doi.org/10.5453/jhps.39.382

A computer code system was developed to evaluate a real-time environmental radiation dose when radioactive substances were accidentally released from a nuclear facility. The examination of the system was performed by using the data of air absorbed dose rate observed at monitoring stations and monitoring posts around the Tokai Reprocessing Plant when Kr was discharged during its normal operation.

Recovery system for uranium from seawater using braid type adsorbent

Shimizu, Takao*; Tamada, Masao; Seko, Noriaki; Sakaguchi, Isamu*

Kaiyo Kaihatsu Rombunshu, 18, p.737 - 742, 2002/06

https://doi.org/10.2208/prooe.18.737

Total amount of uranium in seawater is 4.5 billion tons corresponding to 45,000 times of annual demand for nuclear fuel in the world, though its concentration is only 3.3 mg/m3. The target of this study is that the cost-down of uranium collection from the sea to three times of the market price. This price is cheaper than the recycle fuel by nuclear reprocessing. The present study proposed a high performance adsorbent made by means of both radiation induced graft polymerization and braid technique. The drag force of the braid type adsorbent in water channel was measured. In the west coast of Okinawa prefecture, the adsorption of uranium and the adhesion of sea creature were investigated. It was clarified that reduction of the drag force by the deformed braid adsorbent in the water flow, the increment of uranium adsorption owing to high temperature of seawater, and little adhesion of the creature.

Biological effect of penetration controlled irradiation with ion beams

Tanaka, Atsushi; Shimizu, Takashi*; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Yamashita, Takao*; Watanabe, Hiroshi

JAERI-Conf 97-003, p.323 - 326, 1997/03

no abstracts in English

Cost estimation for recovery of uranium from seawater with braid type adsorbent

Tamada, Masao; Seko, Noriaki; Kasai, Noboru; Shimizu, Takao*

no journal, , 

Recovery cost of uranium from seawater was estimated on the conditions of annual 1200 ton-scale recovery and 2g-U/kg-adsorbent (hereafter ad) for adsorbent performance after 60 days soaking in seawater. The adsorbent was supposed to be used for 6 times and the six cycles of soaking were carried out annually. In these conditions, the uranium cost was estimated at 88 thousands yen/kg-U. If the repeatability of adsorbent increased up to 18 times, the cost became 48 thousands yen/kg-U. Further increment to 60 times reduced the cost to 34 thousands yen/kg-U. In the marine experiment at Okinawa, 3g-U/kg-ad of uranium adsorption was obtained by dipping an adsorbent chip into seawater for 30 days. This capacity supposed to be extended for 4 g-U/kg-ad for 60 days soaking. This adsorption capacity can lead the cost of 25 thousands yen/kg-U at 18 times usage. In this case, initial investment is 108 billions yen which is one third of the construction cost of one million-kW nuclear plant.

Uranium collection from seawater with adsorbent prepared by radiation-induced graft-polymerization

Tamada, Masao; Kasai, Noboru; Seko, Noriaki; Shimizu, Takao*

no journal, , 

The uranium dissolved in seawater is extremely low concentration of 3.3 ppb. However, the total amount of uranium resource in seawater is 4.5 billons tons which is one thousand times of that in terrestrial ores. For uranium collection from seawater, amidoxime group was selected as a high affinity group in adsorbent. This adsorbent was synthesized by grafting of acrylonitrile and subsequent chemical treatment with hydroxylamine. The collection of uranium from seawater was performed in marine experiments at Aomori and Okinawa, Japan. In Aomori, 350 kg of the fibrous adsorbent stacks were dipped at 7 km offing of Aomori seashore. In total 9 tests over three years, 1 kg of uranium could be collected successfully as a yellow cake. A new braid type adsorbent has been developed to achieve the practical cost of uranium collection. The adsorption performance in Okinawa marine experiment indicated 1.5 g-U/kg-ad for 30 day soaking. The promising collection cost reached 25 thousand yen/kg-U which is equivalent to 96/lb-UO.