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In, Teiji*; Shima, Shigeki*; Nakayama, Tomoharu*; Ishikawa, Yoichi*; Togawa, Orihiko; Kobayashi, Takuya; Kawamura, Hideyuki
Gekkan Kaiyo, 37(9), p.674 - 680, 2005/09
no abstracts in English
Tamada, Masao; Seko, Noriaki; Kasai, Noboru; Shimizu, Takao*
FAPIG, (169), p.3 - 12, 2005/03
Braid adsorbent having functional group of amidoxime is a promising material for the recovery of uranium dissolved in the seawater. This braid adsorbent was made by polyethylene multi-fibers in which amidoxime groups were introduced by radiation-induced graft polymerization and subsequent chemical treatment. Reaction time for graft polymerization was 5 h and the resulted braid adsorbent had 2.8 mmol/g-adsorbent of amidoxime group. The braid adsorbent obtained was moored at the offing of Okinawa Island. The adsorption of uranium reached 1.5g/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. It is shown that 134 km
of mooring area is needed for annual product of 1200 tons of uranium. 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.
Seko, Noriaki; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Katakai, Akio; Sugo, Takanobu*
JAERI-Tech 2004-076, 78 Pages, 2005/01
JAERI-Tech-2004-076.pdf:17.11MB
In September 1999, we have soaked 200 kg of fibrous amidoxime adsorbents, synthesized by radiation-induced graft polymerization, into seawater to evaluate their performance. Fractional elution facility was set effectively to elute the rare metals on adsorbents in Mutsu-Establishment. This facility consists of two parts of pre-washing and elution. The present report dealt with planning, manufacture and setting of fractional facility. Marine organism and slime on adsorbent cassette (290
290160 mm) were washed out and every 72 cassettes were set in elution unit (12101210H1460 mm) with nonwoven materials as a packing to avoid elution loss. In the elution process alkaline and alkaline earth metals were eluted with low concentration hydrochloric acid (0.01M) and rare metals were eluted with high concentration (0.5M) after the packing of elution unit into fractional elution facility.
Shimizu, Takao*; Tamada, Masao
Kaiyo Kaihatsu Rombunshu, 20, p.617 - 622, 2004/06
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.
Tamada, Masao
Genshiryoku Hyakka Jiten ATOMICA (Internet), 15 Pages, 2004/04
no abstracts in English
Shimizu, Takao*; Tamada, Masao; Seko, Noriaki; Sakaguchi, Isamu*
Kaiyo Kaihatsu Rombunshu, 18, p.737 - 742, 2002/06
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.
Tamada, Masao
Enerugi Rebyu, 22(4), p.24 - 26, 2002/03
The Black Current conveys 5.2 million tons of uranium toward the offing of Japan, though uranium concentration is only 3.3 ppb in seawater. Recovery of 0.2% of this resources can supply the uranium for all atomic power plants in Japan. Graft polymerization is a promising technique to prepare adsorbent having high selectivity to uranium in seawater and enough durability in severe sea conditions. To evaluate the activity of the adsorbents the equipment for the recovery of rare metals from seawater was set at the 7 km offing of Mutsu-Sekine, Aomori prefecture on September, 1999. In three years (1999 - 2001) 9 mooring experiments of adsorbents were carried out and 1 kg uranium as yellow cake was recovered. This experiment suggested that hydrophilic monomer and trunk polymer should be improved to realized the higher activity for uranium recovery from seawater.
Tamada, Masao; Kasai, Noboru; Seko, Noriaki; Hasegawa, Shin; Takeda, Hayato*; Katakai, Akio; Sugo, Takanobu
JAERI-Tech 2000-072, 40 Pages, 2000/12
JAERI-Tech-2000-072.pdf:10.9MB
no abstracts in English
Kobayashi, Takuya; Lee, S.; Chino, Masamichi
Proceedings of 4th International Conference on Supercomputing in Nuclear Applications (SNA 2000) (CD-ROM), 9 Pages, 2000/09
no abstracts in English
March, 2000); Shinohara, Kunihiko; ; ; ; Isozaki, Tokuju; ; *
JNC TN8440 2000-003, 93 Pages, 2000/08
The investigation on the radioactivity concentration for gross beta, 
H and 
Cs in seawater collected around the discharge point had been performed in order to grasp the change of the activity level of the coastal seawater offshore the JNC Tokai Works from the low level liquid effluent of the reprocessing plant. After the investigation on the radioactivity in seawater during the hot examination, the detailed investigation on the environmental effects from the liquid effluent of JNC reprocessing plant has been performed since July 1978 on the basis of the request from Ibaraki prefecture as the full-scale operation of the reprocessing plant. Consequently, no increase of the radioactive concentration due to the discharged effluent has been observed. And also, as the result of the consideration to the investigation on the environmental effect from the liquid effluent throughout 22 years since 1978, no change of the radioactive concentration level in seawater was recognized.
Tamada, Masao; Seko, Noriaki
Isotope News, p.2 - 6, 2000/04
no abstracts in English
Amano, Hikaru; Yabuuchi, Noriaki; Matsunaga, Takeshi
JAERI-Research 96-049, 125 Pages, 1996/10
JAERI-Research-96-049.pdf:4.04MB
no abstracts in English
