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JAEA Reports

Experiment of incineration for Trans-Uranic (TRU) wastes containing chlorides

Yamashita, Kiyoto; Yokoyama, Aya*; Takagai, Yoshitaka*; Maki, Shota; Yokosuka, Kazuhiro; Fukui, Masahiro; Iemura, Keisuke

JAEA-Technology 2022-020, 106 Pages, 2022/10

JAEA-Technology-2022-020.pdf:4.77MB

Radioactive solid wastes generated by Fukushima Daiichi Nuclear Power Station disaster may contain high levels of salt from the tsunami and seawater deliberately released into the area. It is assumed that polyvinyl chloride (PVC) products may be used for decommissioning work and for containment of radioactive wastes in the future. Among the method of handling them, incineration is one method that needs to be investigated as it is good method for reduction and stabilization of wastes. But in order to dispose of Trans-Uranic (TRU) solid waste containing chlorides, it is necessary to select the structure and materials of the facility based on the information such as the movement of nuclides and chlorides in the waste gas treating system and the corrosion of equipment due to chlorides. Therefore, we decided to get various data necessary to design a study of the incineration facilities. And we decided to examine the transfer behavior of chlorides to the waste gas treatment system, the corrosion-resistance of materials in the incineration facilities, and the distribution survey of plutonium in them obtained using the Plutonium-contaminated Waste Treatment Facility (PWTF), Nuclear Fuel Cycle Engineering Laboratories, which is a unique incinerating facility in Japan. This report describes the transfer behavior of chlorides in the waste gas treatment system, the evaluation of corrosion-resistance materials and the distribution survey of plutonium in the incineration facilities obtained by these tests using the Plutonium-contaminated Waste Treatment Facility, Nuclear Fuel Cycle Engineering Laboratories.

Journal Articles

Concepts and basic designs of various nuclear fuels, 5; Fuels for high temperature gas-cooled reactor and molten salt reactor

Ueta, Shohei; Sasaki, Koei; Arita, Yuji*

Nihon Genshiryoku Gakkai-Shi ATOMO, 63(8), p.615 - 620, 2021/08

https://doi.org/10.3327/jaesjb.63.8_615

no abstracts in English

Journal Articles

Application of phosphate modified CAC for incorporation of simulated secondary aqueous wastes in Fukushima Daiichi NPP, 1; Characterization of solidified cementitious systems with reduced water content

Garcia-Lodeiro, I.*; Lebon, R.*; Machoney, D.*; Zhang, B.*; Irisawa, Keita; Taniguchi, Takumi; Namiki, Masahiro*; Osugi, Takeshi; Meguro, Yoshihiro; Kinoshita, Hajime*

Proceedings of 3rd International Symposium on Cement-based Materials for Nuclear Wastes (NUWCEM 2018) (USB Flash Drive), 4 Pages, 2018/11

Journal Articles

Rust and corrosion mechanism of carbon steel in dilute chloride solution at low dose rates

Motooka, Takafumi

QST-M-8; QST Takasaki Annual Report 2016, P. 73, 2018/03

https://repo.qst.go.jp/records/73811

Previous corrosion test of carbon steel in dilute artificial seawater under Co-60 -ray irradiation has indicated that corrosion rate was enhanced at absorbed dose rates: 100 Gy/h and rust color was changed from black to dark brown. In the present study, the corrosion mechanism of carbon steel under Co-60 -ray irradiation was investigated by identification of rust. rays enhanced oxidation of iron ions from di-valent to tri-valent. Rust formed under irradiation had higher oxidation state.

Journal Articles

Effect of chloride ion on corrosion behavior of SUS316L-grade stainless steel in nitric acid solutions containing seawater components under -ray irradiation

Sano, Yuichi; Ambai, Hiromu; Takeuchi, Masayuki; Iijima, Shizuka; Uchida, Naoki

Journal of Nuclear Materials, 493, p.200 - 206, 2017/09

https://doi.org/10.1016/j.jnucmat.2017.06.017

Times Cited Count：7 Percentile：56.89(Materials Science, Multidisciplinary)

Concerning the Fukushima Daiichi Nuclear Power Plant accident, we investigated the effect of chloride ion on the corrosion behavior of SUS316L stainless steel, which is a typical material for the equipment used in reprocessing, in HNO $_{3}$ solution containing seawater components, including under the -ray irradiation condition. Electrochemical and immersion tests were carried out using a mixture of HNO $_{3}$ and artificial seawater (ASW). In the HNO $_{3}$ solution containing high amounts of ASW, the cathodic current densities increased and uniform corrosion progressed. This might be caused by strong oxidants, such as Cl $_{2}$ and NOCl, generated in the reaction between HNO $_{3}$ and Cl $^{-}$ ions. The corrosion rate decreased with the immersion time at low concentrations of HNO $_{3}$ , while it increased at high concentrations. Under the -ray irradiation condition, the corrosion rate decreased due to the suppression of the cathodic reactions by the reaction between the above oxidants and HNO $_{2}$ generated by radiolysis.

Journal Articles

Quantum optimal control of the isotope-selective rovibrational excitation of diatomic molecules

Kurosaki, Yuzuru*; Yokoyama, Keiichi

Chemical Physics, 493, p.183 - 193, 2017/08

AA2017-0230.pdf:8.02MB

https://doi.org/10.1016/j.chemphys.2017.07.003

Times Cited Count：5 Percentile：21.9(Chemistry, Physical)

Electric field of laser pulses which gives maximum selectivity in the isotope-selective rovibrational excitation of lithium chloride molecules is calculated. Applying the optimal control theory, we calculate optimal electric field to produce mixture of LiCl-35 (=0, =0) and LiCl-37 (=1, =1) from molecular ensemble of LiCl-35 (=0, =0) and LiCl-37 (=0, =0). As a result, it is found that electric field which permit rotational excitations only gives high yield in the selective excitation compared to the electric field which permit both rotational and vibrational excitations.

JAEA Reports

Verification of alternative dew point hygrometer for CV-LRT in MONJU; Short- and long-term verification for capacitance-type dew point hygrometer (Translated document)

Ichikawa, Shoichi; Chiba, Yusuke; Ono, Fumiyasu; Hatori, Masakazu; Kobayashi, Takanori; Uekura, Ryoichi; Hashiri, Nobuo*; Inuzuka, Taisuke*; Kitano, Hiroshi*; Abe, Hisashi*

JAEA-Research 2017-001, 40 Pages, 2017/03

JAEA-Research-2017-001.pdf:5.19MB

In order to reduce the influence on a plant schedule of the MONJU by the maintenance of dew point hygrometers, The JAEA examined a capacitance type dew point hygrometer as an alternative dew point hygrometer for a lithium-chloride type dew point hygrometer which had been used at the CV-LRT in the MONJU. As a result of comparing a capacitance type dew point hygrometer with a lithium-chloride type dew point hygrometer at the CV-LRT (Atmosphere: nitrogen, Testing time: 24 hours), there weren't significant difference between a capacitance type dew point hygrometer and a lithium-chloride type dew point hygrometer. As a result of comparing a capacitance dew point hygrometer with a high-mirror-surface type dew point hygrometer for long term verification (Atmosphere: air, Testing time: 24 months), the JAEA confirmed that a capacitance type dew point hygrometer satisfied the instrument specification (2.04 $^{circ}$ C) required by the JEAC4203-2008.

Journal Articles

Seawater effects on the soundness of spent fuel cladding tube

Motooka, Takafumi; Ueno, Fumiyoshi; Yamamoto, Masahiro

Proceedings of 2016 EFCOG Nuclear & Facility Safety Workshop (Internet), 6 Pages, 2016/09

At the Fukushima Daiichi nuclear accident, seawater was injected into spent fuel pools of Unit 2-4 for the emergency cooling. Seawater might cause localized corrosion of spent fuel cladding. This would lead to leakage of not only fissile materials but also fission products from fuel cladding. The behavior, however, is not understood well. In this paper, the effects of seawater on corrosion behavior and mechanical property of were studied by using a spent fuel cladding from a BWR. We immersed the spent cladding tubes in diluted artificial seawater for 300h at 353 K, and conducted their visual, cross-sectional and strength examinations. As a localized corrosion index, the pitting potentials of specimens fabricated from the cladding were measured as functions of chloride ion concentration ranging from 20 to 2500 ppm. The visual examination showed that localized corrosion has not occurred, and cross-sectional examination showed no cracks. The strength of immersed tubes was comparable to that of non-immersed tubes. Additionally, pitting potential could not be measured over 1.0 V; pitting corrosion was hardly occurred. These results suggested that the specimens from the spent fuel cladding tube was very resistant to localized corrosion.

Journal Articles

Chlorination of UO $_{2}$ and (U,Zr)O $_{2}$ solid solution using MoCl $_{5}$

Sato, Takumi; Shibata, Hiroki; Hayashi, Hirokazu; Takano, Masahide; Kurata, Masaki

Journal of Nuclear Science and Technology, 52(10), p.1253 - 1258, 2015/10

https://doi.org/10.1080/00223131.2015.1070110

Times Cited Count：6 Percentile：45.92(Nuclear Science & Technology)

In order to explore the applicability of the chlorination by MoCl $_{5}$ as a potential pretreatment technique for waste treatment of fuel debris by pyrochemical methods, chlorination experiments of UO $_{2}$ and (U $_{0.5}$ Zr $_{0.5}$ )O $_{2}$ simulated fuel debris were carried out in two steps: the first one is a chlorination reaction by homogeneous heating, the second one is a volatilization of molybdenum by-product by heating under temperature gradient condition. Most of UO $_{2}$ and (U $_{0.5}$ Zr $_{0.5}$ )O $_{2}$ powder were converted to UCl $_{4}$ or UCl $_{4}$ and ZrCl $_{4}$ mixture at 573 K, respectively. In the case of (U $_{0.5}$ Zr $_{0.5}$ )O $_{2}$ sintered particle, most of sample was converted to the chlorides because the products evaporated and be separated from sample surface at 773 K, while only the surface of the sample disk was converted to the chlorides at 573 and 673 K. Most of molybdenum by-product and ZrCl $_{4}$ were separated from UCl $_{4}$ by volatilization at 573 K.

Journal Articles

Spectrophotometric study of Nd $^{2+}$ ions in LiCl-KCl eutectic melt

Hayashi, Hirokazu; Akabori, Mitsuo; Ogawa, Toru; Minato, Kazuo

Zeitschrift fr Naturforschung, A, 59a(10), p.705 - 710, 2004/10

UV and visible spectrophotometric study was made in order to prove the existence of Nd $^{2+}$ ion and clarify the equilibrium among Nd metal, Nd $^{2+}$ , and Nd $^{3+}$ ions in LiCl-KCl eutectic melt. Spectra assigned to Nd $^{2+}$ ion were observed for NdCl $^{2+}$ in (LiCl-KCl) $_{eut.}$ and Nd- NdCl in (LiCl-KCl) $_{eut.}$ melts. Black corrosion products were observed on the surface of the glass cells used for the measurements, where the spectra assigned to Nd $^{2+}$ ion were observed. X-ray diffraction measurements and electron-probe micro-analyses of the corroded glass cells revealed that the corrosion products contained NdOCl.

Journal Articles

Dyed Polyvinyl Chloride films for use as high-dose routine dosimeters in radiation processing

Mai, H. H.*; Duong, N. D.*; Kojima, Takuji

Radiation Physics and Chemistry, 69(5), p.439 - 444, 2004/04

https://doi.org/10.1016/j.radphyschem.2003.08.006

Times Cited Count：21 Percentile：77.78(Chemistry, Physical)

Characteristics of the polyvinyl chloride films containing 0.11wt% of malachite green oxalate or 6GX-setoglausine with 100m in thickness were studied for use as routine dosimeters in radiation processing. These films show basically color bleaching under $^{60}$ Co -ray irradiation in a dose range of 5 to 50 kGy. The sensitivity of the dosimeters and the linearity of dose response curves are improved by adding 2.5% of chloral hydrate [CClCH(OH)] and 0.15% hydroquinone [HOCHOH]. These additions extent the minimum dose limit to 1 kGy covering dosimetric quality assurance in radiation processing of food and healthcare products. The dose responses of both films at irradiation temperatures of 20-35 $^{circ}$ C are constant relative to those at 25 $^{circ}$ C, and the irradiation temperature coefficients for 35-55 $^{circ}$ C were estimated to be (0.43 0.01)%/ $^{circ}$ C. The dosimeter characteristics are stable within 1% at 25 $^{circ}$ C before and 60 days after irradiation.

Journal Articles

Improved density functional calculations including magnetic effects for RfCl $_{4}$ and its homologues

Anton, J.*; Hirata, Masaru; Fricke, B.*; Pershina, V.*

Chemical Physics Letters, 380(1-2), p.95 - 98, 2003/10

https://doi.org/10.1016/j.cplett.2003.09.010

Times Cited Count：6 Percentile：18.14(Chemistry, Physical)

We use the newly developed non collinear spin polarized density functional method to describe the tetrachlorides of element Rutherfordium (Rf) and its homologues. It is the first time that a real three-dimensional molecule is described with this method. Without any additional corrections (used so far for the atomic values) we get nearly complete agreement for all homologues and thus a good prediction for the unknown value for RfCl $_{4}$ .

Journal Articles

Local structure of molten LaCl by K-absorption edge XAFS

Okamoto, Yoshihiro; Shiwaku, Hideaki; Yaita, Tsuyoshi; Narita, Hirokazu; Tanida, Hajime*

Journal of Molecular Structure, 641(1), p.71 - 76, 2002/10

https://doi.org/10.1016/S0022-2860(02)00329-0

Times Cited Count：42 Percentile：71.97(Chemistry, Physical)

The local structure of molten LaCl was investigated by X-ray absorption fine structure(XAFS) of the La K-edge. The nearest La $^{3+}$ -Cl distance andcoordination number were 2.89 and 7.4 from the curve fitting of the 1st peak in the fourier transform magnitude . The coordination number larger than 6 suggests that the local structure of molten LaCl is not a simple octahedral coordination (LaCl) $^{3-}$ , but 7-fold (LaCl) $^{4-}$ and/or 8-fold (LaCl) $^{5-}$ complexes. The 1st La $^{3+}$ -La $^{3+}$ distance, of which correlation was observed as a weak 2nd peak in the , was evaluated to be 4.9. It suggests that the distorted corner-sharing connection of the complex species is predominant in the melt, inontrast with molten YCl in which the edge-sharing connection of the 6-fold (YCl) $^{3-}$ mainly exists.

Journal Articles

XAFS study of molten ZrCl in LiCl-KCl eutectic

Okamoto, Yoshihiro; Motohashi, Haruhiko*

Zeitschrift fr Naturforschung, A, 579(5), p.277 - 280, 2002/05

The local structure of molten ZrCl in LiCl-KCl eutectic was investigated by using an X-ray absorption fine structure(XAFS) of the Zr K-absorption edge. The nearest Zr $^{4+}$ -Cl distance and coordination number from the curve fitting analysis were 2.51 and 5.80.6, respectively. These suggest that a 6-fold coordination (ZrCl) $^{2-}$ is predominant in the mixture melt.