Preface for the special issue "Ambient pressure X-ray photoelectron spectroscopy for observation of surface reactions; Present status and future prospects"

Yoshigoe, Akitaka; Ogawa, Shuichi*; Takakuwa, Yuji*

Hoshako, 35(3), P. 157, 2022/05

Ambient Pressure-XPS [AP-XPS] has been in operation at synchrotron radiation facilities around the world since around 2000 to study gas-surface reactions. Furthermore, it is also applied to observe liquid and solid-liquid interfaces. Development and utilization research is underway as a tool to take the true picture of surface phenomena. A special issue on AP-XPS for the Journal of the Japanese Society for Synchrotron Radiation Research was designed and its purpose is explained.

Verification of alternative dew point hygrometer for CV-LRT in Monju

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

JAEA-Research 2016-021, 32 Pages, 2017/02

JAEA-Research-2016-021.pdf:5.0MB

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 (2.04C) required by the JEAC4203-2008.

Study on tritium removal performance by gas separation membrane with reflux flow for tritium removal system of fusion reactor

Iwai, Yasunori; Yamanishi, Toshihiko; Hayashi, Takumi; Nishi, Masataka

Fusion Science and Technology, 48(1), p.456 - 459, 2005/07

https://doi.org/10.13182/FST05-A964

Addition of gas separation membrane process into usual tritium removal process from atmosphere in a room is attractive for fusion plants where a large amount of atmosphere should be processed. Therefore, the gas separation membrane has been studied. New concept of membrane separation with reflux flow is proposed in the present. Driving force of membrane separation is the difference of partial pressure through membrane. Hence, reflux of a part of gases at permeated side to feed side enhances driving force. Essential points of present discussion are as follows: (1) Reflux has plus effect of driving force enhancement and minus effect of feed flow increase, hence, there is the optimum. (2) Permeated-side pressure effects enhancement of tritium recovery strongly. (3) Effect of reflux becomes striking as the target species have higher permeability coefficient, therefore, it is favorable for tritium recovery because those of hydrogen gas and water vapor are much higher among atmosphere elements. In addition, application of reflux flow will realize scale reduction of expensive membrane module.

Measurement of neodymium(III) and samarium(III) by spectrophotometer and laser-induced photoacoustic spectroscopic system: A Preliminary study for speciation of aqueous Np(IV) species.

Kitamura, Akira; *

JNC TN8400 2001-009, 54 Pages, 2001/01

JNC-TN8400-2001-009.pdf:1.3MB

Spectroscopic measurements of neodymium(III) and samarium(III) were carried out by spectrophotometer and laser-induced photoacoustic spectroscopic (LPAS) system for the investigation of the detection limit of both systems. The absorption spectra and photoacoustic spectra of Nd and Sm were obtained with varying the concentration of the ions from 210 to 210 moldm. The absorption spectrum of Nd was also determined by a special spectrophotometer, of which the measurement cell was set in a glove box filled with inert nitrogen gas. For the comparison with these photoacoustic and absorption spectra, the absorption spectra of Nd and Sm were determined by an usual spectrophotometer with the light-path lengths of 1 cm and 10 cm. The detection limit of the photoacoustic measurement was reported much lower than that of absorbance measurement by several researchers. However, the present study was concluded that the detection limit of photoacoustic measurement with the present LPAS system was similar to that of absorbance measurement with the light-path length of 10 cm. The detection limits of neptunium(IV,V) were estimated and the possibility of the speciation of neptunium(IV) was discussed from the results of the present study.

Direct pH measurement of porewater in compacted bentonite (III); Influence of low alkalinity cement on bentonite porewater

Isogai, Takeshi*; Oda, Chie

JNC TN8400 2000-025, 48 Pages, 2000/09

JNC-TN8400-2000-025.pdf:2.1MB

Porewater chemistly in compacted bentonite would affect a performance of engineered barrier system in a high-level radioactive waste repository, whereas there are little information of the porewater based on experimental data. The previous study provided a new method of direct pH measurement for highly compacted bentonite system and demonstrated some tests for compacted bentonite samples (the dry densities: 1.6 [g/cm] and 1.8 [g/cm]) both with the de-ionized water and with the NaCl solution. In this study, the solution equilibrated with low alkalinity cement were used in the direct pH measurement to see the effect of the composition of the external solutions, in which the bentonite column immersed. The result showed that the pH value of porewater in the cementitious condition was around 9 during the immersed time 1 to 3 months, while after 6 months became the porewater pH 10.6, which was equal to pH of the external solution.

Disassembly and removal of 50MW steam generator test facility; Disassembly and sodium removal of the large cold trap

JNC TN9410 2000-003, 52 Pages, 1999/12

JNC-TN9410-2000-003.pdf:3.51MB

In May, 1999, disassembly and cleansing of sodium residues contained in the large cold trap (50MWSG) were carried out. Two cold trap units, one from the primary sodium loop and the other from the for the secondary sodium loop were disassembled and cleaned. This report describes the procedures, methods, and tasks under taken in the clean-up effort, including countermeasures for safe handling of sodium. The disassembly of the cold trap was based an information regarding similar cleansing activities external to JNC. There was also same a priori knowledge of the type and amount of sodium-laden residues. As this result, we conducted disassembly and cleansing task as provisionally planned. In fact we learned that disassembly methods for the specific components could be conducted in an aerated atmosphere. We thus gained additional disassembly and sodium cleansing experience under manageable and safe conditions.

Measurements of Apparent Diffusion Coefficients (Da)for Ca(I), Ni(II)and Se(IV) in Bentonite with Silica Sand

Sato, Haruo

JNC TN8400 99-060, 12 Pages, 1999/10

JNC-TN8400-99-060.pdf:0.55MB

Apparent diffusion coefficients(Da) of Cs(Cs), Ni(Ni) and Se(SeO) in a Na-bentonite (Kunigel-V1) were measured for a dry density of 1.8 Mgm with silica sand of 30 wt% at room temperature by in-diffusion method to evaluate the effect of the mixture of silica sand on Da in bentonite. The experiments for Cs and Ni were carried out under aerobic condition, but those for Se which is redox sensitive were carried out in an Ar glove-box (O concentration 0.1 ppm). Consequently, no significant effect of silica sand mixture to the bentonite on Da values of Cs and Se was found, and the obtained Da values were approximately the same as those in the system without silica sand reported so far. On the other hand, Da values of Ni in bentonite with silica sand were 2 orders of magnitude lower than those in bentonite without silica sand obtained to date. The Da values of Ni reported so far were obtained using stable isotopic tracer and a tracer solution with fairly high Ni concentration compared with concentration used in this study was introduced. Additionally, it is known that distribution coefficient (Kd) of Ni on Na-montmorillonite which is the major constituent clay mineral of Kunigel-V1 decreases with increasing Ni concentration. Based on this, the abrupt decrease in Da values of Ni for bentonite with silica sand is considered to be due to the difference of sorption caused by the difference of Ni concentration in the porewater of bentonite.

None

Shimogori, Kazutoshi*; Tomari, Haruo*; *; Fujiwara, Kazuo*; Masugata, Tsuyoshi*

PNC TJ1074 98-002, 270 Pages, 1998/02

PNC-TJ1074-98-002.pdf:25.03MB

None

Development and validation of sodium fire analysis code, ASSCOPS

; ; Tanabe, Hiromi; Ohno, Shuji; Miyake, Osamu;

PNC TN9410 97-030, 93 Pages, 1997/04

PNC-TN9410-97-030.pdf:2.2MB

A sodium fire analysis code, ASSCOPS(Analysis of Simultaneous Sodium Combustions in Pool and Spray) was developed coupling the computer codes of SPRAY-IIIM and SOFIRE-MIl to assess temperature-pressure transients resulting from sodium spray and pool combustions, simultaneously. The validation of ASSCOPS was conducted using the experimental results obtained from sodium spray fire experiments using 21 m vessel and the accuracy of calculated results was discussed. The following results were obtained: (1)Study under inert gas atmosphere. The comparison between analysis and experiment with regard to the pressure and the temperature showed a good agreement. (2)Study under air atmosphere. The comparison between analysis and experiment with regard to the pressure and the temperature also showed a good agreement. (3)Effects of parameter used in evaluating the design of Monju. The peak pressure and temperature obtained by the analysis overestimates the experimental results. From these results, it was concluded that the development and validation of ASSCOPS indicate a improvement on the burning and the heat transfer models in SPRAY-IIIM.

None

Sazarashi, Masami*; *; Ikeda, Yasuhisa*; Kumagai, Mikio*; *; *

PNC TJ1564 97-002, 20 Pages, 1997/03

PNC-TJ1564-97-002.pdf:0.67MB

None