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JAEA Reports

Clearance of concrete generated from modification activities of JRR-3; Results for measuring and evaluating radioactivity concentration

Ogoshi, Yurie; Satoyama, Tomonori; Kishimoto, Katsumi; Nanri, Tomohiro; Suzuki, Takeshi; Tomioka, Osamu; Takaizumi, Hirohide*; Kanno, Tomoyuki*; Maruyama, Tatsuya*

JAEA-Technology 2017-017, 152 Pages, 2017/08

JAEA-Technology-2017-017.pdf:15.97MB

At Nuclear Science Research Institute, clearance works for about 4,000 tons of extremely low-level radioactive concrete debris, which were generated from the modification activities of JRR-3 from FY 1985 to FY 1989 and stored in the waste storage facility NL, carried out. First of this clearance works, method for measuring and evaluating radioactivity concentration was approved by Minister of MEXT on July 25, 2008. And then, clearance works were started from FY 2009. Measuring and evaluating radioactivity concentration was achieved by using the approved method, and was confirmed by government. And then, clearance works were completed in FY 2014. The clearance concrete was recycled as a material for restoration works of the 2011 off the Pacific coast of Tohoku Earthquake. This report summarizes the results of measuring and evaluating radioactivity concentration, achievement of confirmation by government, recycling of cleared concrete and cost for clearance works.

Journal Articles

Clearance of concrete debris generated from modification work of JRR-3

Satoyama, Tomonori; Nanri, Tomohiro; Kishimoto, Katsumi

Hoken Butsuri, 49(4), p.180 - 189, 2014/12

JAEA planned to apply the clearance system to slightly contaminated concrete debris with radionuclides, which was generated from the modification of the JRR-3. The modification work was conducted from 1985 to 1990 and the generated concrete debris has been stored as radioactive waste in interim storage facilities. JAEA established procedures for measuring and evaluating the radioactivity concentration of sored concrete debris. In 2008, the authority approved these procedures for clearance. Since 2009, JAEA have been measuring and evaluating the radioactivity concentration of concrete debris, using the approved procedures. By the end of 2012, the authority had confirmed the correctness of our measurement and evaluation results on about 2,600 tons of concrete debris. About 1,800 tons of those cleared concrete were recycled to flat surface subsidence in the NSRI caused by the Great East Japan Earthquake, and also used as base material to construct new buildings and parking lots.

Journal Articles

Clearance of concrete debris generated from modification of JRR-3

Satoyama, Tomonori; Nanri, Tomohiro; Kishimoto, Katsumi

Dekomisshoningu Giho, (49), p.11 - 21, 2014/03

Japan Atomic Energy Agency at the Nuclear Science Research Institute (NSRI) planned to apply the clearance system to about 4,000 tons of slightly contaminated concrete debris with radionuclides, which was generated from the modification of the Japan Research Reactor No.3 (JRR-3). The modification work was conducted from 1985 to 1990 and the generated concrete debris has been stored as radioactive waste in interim storage facilities in the NSRI. In 2008, the authority approved procedures for measuring and evaluating the radioactivity concentration of stored concrete debris. Since 2009, NSRI have been measuring and evaluating the radioactivity concentration of concrete debris, using the approved procedures. By the end of 2013, the authority had confirmed the correctness of our measurement and evaluation results on about 3,000 tons of concrete debris. About 1,800 tons of those cleared concrete were recycled as backfilling material in depressed areas around buildings caused by the Great East Japan Earthquake, and as roadbed material of the parking lots in the NSRI.

Journal Articles

Anionic fluoro complex of element 105, Db

Kasamatsu, Yoshitaka*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Li, Z.; Ishii, Yasuo; Tome, Hayato*; Sato, Tetsuya; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.

Chemistry Letters, 38(11), p.1084 - 1085, 2009/10

 Times Cited Count:14 Percentile:49.15(Chemistry, Multidisciplinary)

We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z = 105 in HF/HNO$$_{3}$$ solution at the fluoride ion concentration [F$$^{-}$$] = 0.003 M. The result clearly demonstrates that the fluoro complex formation of Db is significantly different from that of the group-5 homologue Ta in the 6th period of the periodic table while the behavior of Db is similar to that of the lighter homologue Nb in the 5th period.

Oral presentation

Anion-exchange behavior of element-105 (Db) in HF/HNO$$_3$$ solutions using a newly developed on-line experimental system

Tsukada, Kazuaki; Kasamatsu, Yoshitaka; Asai, Masato; Toyoshima, Atsushi; Ishii, Yasuo; Li, Z.; Kikuchi, Takahiro; Sato, Tetsuya; Nishinaka, Ichiro; Nagame, Yuichiro; et al.

no journal, , 

Anion-exchange chromatographic behavior of element 105, dubnium (Db), produced in the $$^{248}$$Cm($$^{19}$$F,5n)$$^{262}$$Db reaction is investigated together with the homologues Nb and Ta in HF/HNO$$_3$$ mixed media using a newly developed on-line experimental system. The result indicates that the adsorption sequence on the anion-exchange resin is Ta$$gg$$Nb$$geq$$Db, and the fluoride complex formation of Db is expected to be weaker than that of homologues.

Oral presentation

Anion-exchange behavior of Db in HF/HNO$$_{3}$$ mixed solution using a new on-line chemical apparatus

Tsukada, Kazuaki; Kasamatsu, Yoshitaka*; Asai, Masato; Toyoshima, Atsushi; Ishii, Yasuo; Li, Z.; Kikuchi, Takahiro; Sato, Tetsuya; Nishinaka, Ichiro; Nagame, Yuichiro; et al.

no journal, , 

Anion-exchange chromatographic behavior of element 105, dubnium (Db), produced in the $$^{248}$$Cm($$^{19}$$F,5n) reaction is investigated together with the homologues Nb and Ta in HF/HNO$$_{3}$$ mixed media using a newly developed on-line experimental system. The result indicates that the adsorption sequence on the anion-exchange resin is Ta $$gg$$ Nb $$geq$$ Db, and the fluoride complex formation of Db is expected to be weaker than that of homologues.

Oral presentation

Anion-exchange behavior of Db in HF/HNO$$_{3}$$ mixed solution using an on-line chemical apparatus

Tsukada, Kazuaki; Kasamatsu, Yoshitaka*; Asai, Masato; Toyoshima, Atsushi; Ishii, Yasuo; Li, Z.; Kikuchi, Takahiro; Sato, Tetsuya; Nagame, Yuichiro; Sch$"a$del, M.; et al.

no journal, , 

We have investigated the chemical behavior of Db together with its group-5 homologues by anion-exchange chromatography in HF/HNO$$_{3}$$ mixed solution using a rapid online chemical apparatus (AIDA-II). The nuclides $$^{262}$$Db, $$^{88}$$Nb and $$^{169,170}$$Ta were produced in the $$^{248}$$Cm($$^{19}$$F, ${it 5}$n), $$^{nat}$$Ge($$^{19}$$F, ${it x}$n) and $$^{nat}$$Gd($$^{19}$$F, ${it x}$n) reactions, respectively, at the JAEA tandem accelerator. On-line anion-exchange separations of Db, Nb and Ta were performed using the AIDA-II. Thousand times of anion-exchange separations were conducted using AIDA-II. $$alpha$$ events were registered, and the $${it K_d}$$ values for Db was evaluated. From these results, the adsorption sequence Pa $$<$$ Db $$<$$ Nb $$ll$$ Ta was determined. The present result shows a notable difference in the adsorption behavior between Db and its homologue Ta. In the conference, the present status and the perspective of the aqueous chemistry of Db at JAEA will be also presented.

Oral presentation

Clearance of concrete debris generated from modification work of JRR-3, 5; Result of measurement and evaluation of radioactivity distribution

Nanri, Tomohiro; Kishimoto, Katsumi; Satoyama, Tomonori; Takaizumi, Hirohide; Kanno, Tomoyuki; Maruyama, Tatsuya; Yoshimori, Michiro

no journal, , 

no abstracts in English

Oral presentation

Clearance of concrete debris generated from modification work of JRR-3, 4; Progress of clearance work

Satoyama, Tomonori; Kishimoto, Katsumi; Nanri, Tomohiro; Takaizumi, Hirohide; Kanno, Tomoyuki; Maruyama, Tatsuya; Yoshimori, Michiro

no journal, , 

no abstracts in English

Oral presentation

Radiation control for clearance of concrete wastes generated from JRR-3 renewal

Furutani, Misa; Aoyagi, Hiroyuki*; Shirato, Yoshihiro; Nojima, Shun; Nakagawa, Masahiro; Otsuka, Yoshikazu; Niinuma, Shinichi*; Sakai, Toshiya; Muto, Yasushi; Nanri, Tomohiro; et al.

no journal, , 

no abstracts in English

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