Yamamoto, Masahiko; Horigome, Kazushi; Kuno, Takehiko
Applied Radiation and Isotopes, 190, p.110460_1 - 110460_7, 2022/12
Gravimetric measurement of U content in UO with ignition in the air has been investigated. The ignition temperature, ignition time and aliquot sample mass are optimized as 900C, 60 minutes, and 1 g, respectively. The method is validated by IDMS with uncertainty estimation. The obtained result by gravimetry is 0.782360.00051 g/g (k=2) and agreed with IDMS value within its uncertainty. It has been found that U in UO can be measured accurately and precisely by gravimetry.
Komeda, Masao; Toh, Yosuke
Applied Radiation and Isotopes, 188, p.110391_1 - 110391_6, 2022/10
Tohamy, M.*; Abbas, K.*; Nonneman, S.*; Rodriguez, D.; Rossi, F.
Applied Radiation and Isotopes, 173, p.109694_1 - 109694_7, 2021/07
Nagaoka, Mika; Fujita, Hiroki; Aida, Taku*; Guo, H.*; Smith, R. L. Jr.*
Applied Radiation and Isotopes, 168, p.109465_1 - 109465_6, 2021/02
The radioactivities in the environmental samples are analyzed to monitor the nuclear power facilities. The pretreatment of radioactive nuclides of alpha and beta emitters in the environmental samples is performed with acid to decompose organic matter and extract object nuclide such as Sr, U and Pu. However, the pretreatment methods are time-consuming and used many concentrated acid solutions that are unsafe and hazardous. Therefore, we develop to the new pretreatment method using supercritical water instead of acid. Hydrothermal pretreatment of soils (Andosols) from Ibaraki prefecture (Japan) was used to improve methods for monitoring radioactive Sr and U. Calcined samples were pretreated with subcritical or supercritical water (SCW) followed by extraction with 0.5 M HNO solutions. With SCW pretreatment, recoveries of Sr and U were 70% and 40%, respectively. Experimental recoveries obtained can be described by a linear relationship in water density. The proposed method is robust and can lower environmental burden of routine analytical protocols.
Ikebe, Yurie*; Oshima, Masumi*; Bamba, Shigeru*; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Toyoshima, Atsushi*; Bi, C.*; Seto, Hirofumi*; Amano, Hikaru*; et al.
Applied Radiation and Isotopes, 164, p.109106_1 - 109106_7, 2020/10
Boron Neutron Capture Therapy (BNCT) is a radiotherapy for the treatment of intractable cancer. In BNCT precise determination of B concentration in whole blood sample before neutron irradiation is crucial for control of the neutron irradiation time and the neutron dosimetry. We have applied the Charged Particle Activation Analysis (CPAA) to non-destructive and accurate determination of B concentration in whole blood sample. The experiment was performed at JAEA Tandem Accelerator using an 8 MeV proton beam. The 478 keV ray of Be produced in the B(p,)Be reaction was used to quantify the B, and rays of Co originating from the reaction with Fe in blood was used to normalize the -ray intensity. The results demonstrated that the present CPAA method can be applied to the determination of the B concentration in the blood sample.
Rodriguez, D.; Rossi, F.; Takahashi, Tone; Seya, Michio*; Koizumi, Mitsuo
Applied Radiation and Isotopes, 159, P. 109083_1, 2020/05
Yamamoto, Masahiko; Taguchi, Shigeo; Do, V. K.; Kuno, Takehiko; Surugaya, Naoki
Applied Radiation and Isotopes, 152, p.37 - 44, 2019/10
An online measurement system using an alpha liquid scintillation counter (-LSC) coupled to microchip solvent extraction has been developed. A flow-through cell of -LSC has been prepared by packing PTFE tube into glass tube to combine microchip. Two-phase flow in microchannel has been stabilized by using coiled tube. The Pu in organic phase has been mixed with scintillation cocktail by T-junction connectors. The system separates and detects Pu by online with detection limit of 6.5 Bq/mL, generating only L-level wastes.
Yin, Y.-G.*; Ishii, Satomi*; Suzui, Nobuo*; Igura, Masato*; Kurita, Keisuke; Miyoshi, Yuta*; Nagasawa, Naotsugu*; Taguchi, Mitsumasa*; Kawachi, Naoki*
Applied Radiation and Isotopes, 151, p.7 - 12, 2019/09
Accurate analysis of N fixation in leguminous crops requires determination of N utilization within an intact plant however, most approaches require tissue disassembly. We developed a simple and rapid technique to generate high-purity and high-yield [N]N gas and obtained real-time images of N fixation in an intact soybean plant. The purification efficiency was 81.6% after decay correction.
Tomita, Jumpei; Takeuchi, Erina
Applied Radiation and Isotopes, 150, p.103 - 109, 2019/08
A rapid analytical method for determining Sr in urine samples (1-2 L) was developed to assess the internal exposure of workers in a radiological emergency. Strontium in a urine sample was rapidly separated by phosphate co-precipitation, followed by extraction chromatography with a tandem column of Pre-filter, TRU and Sr resin, and the Sr activity was determined by ICP-MS/MS. Measurement in the MS/MS mode with an O reaction gas flow rate 1 mL min showed no tailing of Sr at m/z = 90 up to 50 mg-Sr L. The interferences of Ge, Se and Zr at m/z = 90 were successfully removed by chemical separation. This analytical method was validated by the results of the analyses of synthetic urine samples (1.2-1.6 L) containing a known amount of Sr along with 1 mg of each of Ge, Se, Sr and Zr. The turnaround time for analysis was about 10 h, and the detection limit of Sr was approximately 1 Bq per urine sample.
Rodriguez, D.; Rossi, F.; Takahashi, Tone; Seya, Michio; Koizumi, Mitsuo
Applied Radiation and Isotopes, 148, p.114 - 125, 2019/06
Yokoyama, Kaoru; Ohashi, Yusuke
Applied Radiation and Isotopes, 145, p.19 - 23, 2019/03
Dismantled materials generated from nuclear facilities are reused or directed to repository sites. If scrap metals with complicated shapes can be cleared, the amounts of radioactive waste can be reduced. A clearance verification system is constructed to determine the amount of uranium in decontaminated metals in a drum using the 1.001 MeV gamma rays of Pa, produced in the decay of U. The experimental study with simulated waste drums demonstrated that the quantification errors of uranium fall within 25% for 0.5g of uranium.
Hirouchi, Jun; Nishizawa, Yukiyasu*; Urabe, Yoshimi*; Shimada, Kazumasa; Sanada, Yukihisa; Munakata, Masahiro
Applied Radiation and Isotopes, 141, p.122 - 129, 2018/11
Ho, H. Q.; Honda, Yuki*; Hamamoto, Shimpei; Ishii, Toshiaki; Fujimoto, Nozomu*; Ishitsuka, Etsuo
Applied Radiation and Isotopes, 140, p.209 - 214, 2018/10
Ho, H. Q.; Honda, Yuki; Motoyama, Mizuki*; Hamamoto, Shimpei; Ishii, Toshiaki; Ishitsuka, Etsuo
Applied Radiation and Isotopes, 135, p.12 - 18, 2018/05
Shiiba, Takuro*; Kuga, Naoya*; Kuroiwa, Yasuyoshi*; Sato, Tatsuhiko
Applied Radiation and Isotopes, 128, p.199 - 203, 2017/10
We calculated scaled dose point kernels (DPKs) for mono-energetic electron in water (0.015, 0.1, 1.0, and 2.0 MeV) and compact bone (0.010 and 1 MeV) using the latest version of PHITS. Furthermore, we calculated beta-emitting isotopes (Sr, Y, I) DPKs in both water and bone. The simulated results of mono-energetic electron and beta-emitting DPKs were compared with those in literature using different MC codes, such as EGSnrc, GATE6.0, MCNP4C, and FLUKA. All mono-energetic and beta-emitting isotope DPKs calculated using PHITS, both in water and compact bone, were in good agreement with those in literature using other MC codes. The differences were 4% for all mono-energetic electron and beta-emitting isotope DPKs in both water and bone. PHITS provided reliable mono-energetic electron and beta-emitting isotope scaled DPKs in both water and compact bone for patient-specific dosimetry.
Sanada, Yukihisa; Orita, Tadashi; Torii, Tatsuo
Applied Radiation and Isotopes, 118, p.308 - 316, 2016/12
An unmanned helicopter monitoring system (UHMS) was developed to survey the environmental effect of radioactive cesium scattered as a result of the Fukushima Daiichi Nuclear Power Station accident. The UHMS was mainly used to monitor the area surrounding the Fukushima Daiichi Nuclear Power Station six times from 2012 to 2015. Quantitative changes in the radioactivity distribution trend were revealed from the results of these monitorings runs.
Komeda, Masao; Arai, Masaji; Tamai, Kazuo*; Kawasaki, Kozo*
Applied Radiation and Isotopes, 113, p.60 - 65, 2016/07
We designed and fabricated a new type holder that achieved uniform doping under long-term use at JRR-3. The new type holder uses an aluminum alloy and BC particles as filter materials to ensure uniform vertical flux distribution. Although the amount of filter material decreases with long-term use, it was found that the doping distribution did not change by much until 800 h. The lifetime of the new type holder (of the order of hundreds of hours) depends mainly on the amount of trapped radioactive isotopes. This indicates that the decrease in filtering ability over the filter's lifetime is not significant. The filtering ability remains stable for a long time, and the difference in the vertical doping distribution is 1.08 at 1600 h and 1.18 at 4000 h. The irradiation efficiency is expected to increase by 1.7 times when using the new type holder.
Hata, Haruhi; Yokoyama, Kaoru; Ishimori, Yuu; Ohara, Yoshiyuki; Tanaka, Yoshio; Sugitsue, Noritake
Applied Radiation and Isotopes, 104, p.143 - 146, 2015/10
We investigated the feasibility of using support vector machine (SVM), a computer learning method, to classify uranium waste drums as natural uranium or reprocessed uranium based on their origins. The method was trained using 12 training datasets were used and tested on 955 datasets of -ray spectra obtained with NaI(Tl) scintillation detectors. The results showed that only 4 out of 955 test datasets were different from the original labels-one of them was mislabeled and the other three were misclassified by SVM. These findings suggest that SVM is an effective method to classify a large quantity of data within a short period of time. Consequently, SVM is a feasible method for supporting the scaling factor method and as a supplemental tool to check original labels.
Angell, C.; Pedretti, M.*; Norman, E. B.*
Applied Radiation and Isotopes, 98, p.34 - 39, 2015/04
Suzuki, Daisuke; Esaka, Fumitaka; Miyamoto, Yutaka; Magara, Masaaki
Applied Radiation and Isotopes, 96, p.52 - 56, 2015/02
Isotope ratios of uranium and plutonium in individual U-Pu mixed particles with various U/Pu ratios were determined by thermal ionization mass spectrometry with a continuous heating method without chemical separation. Prior to the measurements, micron-sized U-Pu mixed particles with U/Pu ratios of 1, 5, 10, 18 and 70 were produced by using certified reference materials CRM U-010 (1%U enriched, NBL) and SRM 947 (NBS) solutions. As a result of isotope ratio analysis, accurate values for U and Pu ratios, except for Pu/Pu, were successfully determined for the particles with all U/Pu ratios. Although some pre-treatment such as chemical separation would need for accurate determination of Pu/Pu isotope analysis, it was shown that this analytical technique has a potential of powerful tool for nuclear safeguards and forensics.