Development of HCl-free solid phase extraction combined with ICP-MS/MS for rapid assessment of difficult-to-measure radionuclides, 2; Highly sensitive monitoring of Sn in concrete rubble

Do, V. K.; Furuse, Takahiro; Ota, Yuki; Iwahashi, Hiroyuki; Hirosawa, Takashi; Watanabe, Masahisa; Sato, Soichi

Journal of Radioanalytical and Nuclear Chemistry, 331(12), p.5631 - 5640, 2022/12

https://doi.org/10.1007/s10967-022-08612-7

Sn is one of the long-lived fission products that might have been released into the environment after the Fukushima nuclear accident in Japan in 2011. The presence of radionuclides must be monitored for the proper treatment of wastes obtained from decommissioning accident-related nuclear facilities and the surrounding environment. In the work, we propose a reliable method for verifying the presence of Sn in construction materials by combining the HCl-free solid phase extraction on TEVA resin and a selective measurement by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). The method has been optimized and characterized step by step. More than 95% of chemical recovery was achieved for Sn from typical concrete matrixes. The interference caused by an isobar Te and possible polyatomic interferences from matrixes were effectively suppressed by the developed chemical separation and the tandem MS/MS configuration. The total decontamination factor for the Te interference was of the order of 10. The estimated method detection limit for Sn in concrete as measured at m/z = 160 was 12.1 pg g, which is equivalent to 6.1 mBq g.

Development of HCl-free solid phase extraction combined with ICP-MS/MS for rapid assessment of difficult-to-measure radionuclides, 1; Selective measurement of Zr and Mo in concrete rubble

Do, V. K.; Furuse, Takahiro; Murakami, Erina; Aita, Rena; Ota, Yuki; Sato, Soichi

Journal of Radioanalytical and Nuclear Chemistry, 327(1), p.543 - 553, 2021/01

https://doi.org/10.1007/s10967-020-07503-z

A new HCl-free chromatographic separation procedure has been developed for sequential separation of Zr and Mo from concrete matrices. Accordingly, Zr and Mo could be sensitively and selectively measured by ICP-MS/MS using ammonia reaction gas. The recoveries of greater than 90% for Zr and Mo from concretes could be achieved. The measurement condition was optimized for complete suppression of interferences from Nb and peak tailing from abundant isotopes of Zr and Mo in concrete matrices. The removal of interferences was verified by measurement of radio-contamination-free concretes used as a sample matrix blank. Method detection limits of 1.7 mBq g and 0.2 Bq g were achieved for Zr and Mo, respectively, in the concrete matrices. The interference removal factor for Nb (equivalent to the decontamination factor in radiochemical separation) was of the order of 10, and the abundance sensitivity was of the order of 10, indicating that the developed method is reliable for verifying the presence of ultralow concentrations of Zr and Mo. The present method is suitable for the rapid assessment of Zr and Mo for radioactivity inventory of concrete rubble.

The Outline of Japan Atomic Energy Agency's Okuma Analysis and Research Center, 1; The Total progress of Labolatory-1 and Labolatory-2

Inoue, Toshihiko; Ogawa, Miho; Sakazume, Yoshinori; Yoshimochi, Hiroshi; Sato, Soichi; Koyama, Shinichi; Koyama, Tomozo; Nakayama, Shinichi

Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 7 Pages, 2017/00

http://hotlab.sckcen.be/proceedings

Decommissioning of TEPCO's 1F is in progress according to the Roadmap. The Roadmap assigned the construction of a hot laboratory and analysis to the JAEA. The hot laboratory, Okuma Analysis and Research Center consists of the three buildings; Administrative building, the Laboratory-1 and Laboratory-2. The Laboratory-1 and Laboratory-2 are hot laboratories. Laboratory-1 is for radiometric analysis of low and medium level radioactive rubble and secondary wastes. The license of the Laboratory-1's implementation was approved by The Secretariat of the Nuclear Regulation Authority and the construction started in April 2017 and plans an operational start in 2020. Laboratory-2 provides concrete cells, steel cells for the analysis of the fuel debris and high level radioactive rubble. The Laboratory-2's major analysis items is reviewed by review meeting organized of cognoscente.

Measurement of hydrogen generating from radiolysis of highly active liquid waste and its quantitative evaluation

Yamamoto, Masahiko; Surugaya, Naoki; Mori, Eito; Taguchi, Shigeo; Sato, Soichi

JAEA-Research 2015-013, 27 Pages, 2015/10

JAEA-Research-2015-013.pdf:2.84MB

The H concentration generating from Highly Active Liquid Waste (HALW) of Tokai Reprocessing Plant is measured in a closed experimental system. The experimental results show that H concentration gradually increases at first and then approaches a steady-state due to the H consumption reaction by Pd ions. The highest H concentration is 1200 ppm (0.1%) when the solution temperature is at 23C. It is found that H generating from HALW is equilibrated one order of magnitude lower than the H combustion lower limit. Moreover, a model based on H generation from HALW by the radiolysis and H consumption reaction by Pd ions is proposed and applied to evaluate H concentration behavior in the gas phase. The calculated H concentrations from proposed model agreed well with the experimental values. It is demonstrated that the behavior of H generating from HALW can be evaluated quantitatively by applying the proposed model in this study.

The Cause of corrosion occurred in a glove box filter casing and its repair technique

Mori, Eito; Yamamoto, Masahiko; Taguchi, Shigeo; Sato, Soichi; Kitao, Takahiko; Surugaya, Naoki

Nihon Hozen Gakkai Dai-11-Kai Gakujutsu Koenkai Yoshishu, p.132 - 138, 2014/07

The contamination of the radioactive material was observed on the filter casing surface of the glove box installed at the analytical laboratory in Tokai Reprocessing Plant. The cause of the contamination was investigated with visual inspection, penetrant testing and ultrasonic thickness measurement. It was found that a micro through-hole due to the corrosion of stainless-steel was generated in the glove box filter casing. The repair work of the filter casing was performed keeping the glove box negative pressure. The corrosion part of filter casing was replaced and newly fabricated casing was connected to the glove box with Tungsten Inert Gas welding method.

Estimation of runoff volume by geomorphometry and statistics analysis using digital elevation model in Tono area

Takeuchi, Ryuji; Kosaka, Hiroshi; Sato, Atsuya*; Tomiyama, Shingo*; Kageyama, Soichiro*; Ikeda, Makoto*

JAEA-Research 2011-008, 77 Pages, 2011/06

JAEA-Research-2011-008.pdf:4.76MB

Subsurface water balance observation is a kind of methods in order to estimate a recharge rate. Results of the observation are affected by the various factors such as the scale, the topography, a geological feature, the climate. Therefore, the observation in the regional scale is necessary at many basins. The purpose of this study is to confirm the applicability of the method for the evaluation of runoff volume, which is one of parameters to evaluate the recharge rate by surface water balance observation, by geomorphometry and statistical analyses using digital elevation model (DEM). The runoff index which is the original indicator to evaluate the degree of flow rate on a catchment was calculated by the comparison between the result of geomorphometry and statistics analyses, and the observed data of river flow rate in the monitoring stations. Using this index, the flow rate of the Hiyoshi River was evaluated. The evaluated flow rate was about 60% against the observed flow rate.

Azimuthal correlations of electrons from heavy-flavor decay with hadrons in and Au+Au collisions at = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.

Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04

https://doi.org/10.1103/PhysRevC.83.044912

Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.

Spectrophotometric determination of plutonium in highly radioactive liquid waste using an internal standardization technique with Neodymium(III)

Surugaya, Naoki; Taguchi, Shigeo; Sato, Soichi; Watahiki, Masaru; Hiyama, Toshiaki

Analytical Sciences, 24(3), p.377 - 380, 2008/03

https://doi.org/10.2116/analsci.24.377

A simple and rapid spectrophotometric method has been developed for the determination of Pu in highly radioactive liquid waste. This method uses Nd(III) as an internal standard, which enables us to determine the concentration of Pu and to authenticate the whole analytical scheme as well. A Nd(III) standard was mixed with a sample solution and Pu was quantitatively oxidized to Pu(VI) with Ce(IV) in a nitric acid medium, having maximum absorbance at 830 nm. The spectrophotometric measurement of Pu(VI) was subsequently performed to determine the concentration compared with maximum absorbance of Nd(III) at 795nm. The proposed method was validated through comparison experiments with isotope dilution mass spectrometry and was successfully applied to the analysis for the nuclear waste management at spent nuclear fuel reprocessing plants.

Sulfurization of rare-earth oxides in simulated spent fuel

Shinohara, Genki*; Sato, Nobuaki*; Kirishima, Akira*; Tochiyama, Osamu*; Sato, Soichi

Proceedings of 16th Iketani Conference: Masuko Symposium, p.153 - 160, 2006/11

For the recovery of uranium from spent nuclear fuel, the sulfide reprocessing process has been proposed. The process consists of voloxidation and sulfurization steps followed by either magnetic separation or selective leaching steps. In this process, selective sulfurization of the rare-earth elements is applied, while the uranium oxide remains unreacted. The sulfurization of rare-earth oxides RO (R=Nd, Eu) was examined using CS, and found that they formed oxysulfide and sulfides even at temperatures lower than 500C. From the results of the sulfurization of RO in the simulated spent fuel, it was found that RO for Nd and Eu were selectively sulfurized by CS at 500C forming NdS and EuS, respectively, while uranium remained as UO. Effects of sulfurizing temperature and time were also investigated and compared with the results of thermodynamic consideration.

Determination of plutonium in highly radioactive liquid waste by spectrophotometry using neodymium as an internal standard for safeguards analysis; Japan Support Program for Agency Safeguards (JASPAS), JC-19

Taguchi, Shigeo; Surugaya, Naoki; Sato, Soichi; Kurosawa, Akira; Watahiki, Masaru; Hiyama, Toshiaki

JAEA-Technology 2006-041, 58 Pages, 2006/06

JAEA-Technology-2006-041.pdf:4.38MB

We have developed a method of spectrophotometric determination of plutonium (10 M) in highly radioactive liquid waste for safeguards verification analysis. The method offers reduced sample preparation and analysis time compared to isotope dilution mass spectrometry. It uses neodymium as an internal standard, which allows for determining an index for the authentication of the analytical scheme and the inspection procedure. The relative expanded uncertainty of the repeated analysis (n = 5) was 8.9 % (coverage factor k = 2) for a highly radioactive liquid waste sample(173 mgL). The determination limit was calculated to be 6 mgL (ten fold's the standard deviation). This method was validated through comparison experiments with isotope dilution mass spectrometry. The analytical results of plutonium in highly radioactive liquid waste using this method were in good agreement with those obtained using isotope dilution mass spectrometry. It is to be noted that the neodymium standard is intended to be provided by the inspector so that an inspector can check the instrument conditions as well as the analytical scheme. The proposed method was successfully applied for the independent on-site safeguards analysis at the Tokai Reprocessing Plant.