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Kawaguchi, Munemichi; Miyahara, Shinya; Uno, Masayoshi*
Journal of Nuclear Science and Technology, 56(6), p.513 - 520, 2019/06
Times Cited Count：2 Percentile：21.22(Nuclear Science & Technology)This study revealed melting points and thermal conductivities of four samples generated by sodium-concrete reaction (SCR). We prepared the samples using two methods such as firing mixtures of sodium and grinded concrete powder, and sampling depositions after the SCR experiments. In the former, the mixing ratios were determined from the past experiment. The latter simulated the more realistic conditions such as the temperature history and the distribution of Na and concrete. The thermogravimetry-differential thermal analyzer (TG-DTA) measurement showed the melting points were 865-942
C, but those of the samples containing metallic Na couldn't be clarified. In the two more realistic samples, the compression moldings in a furnace were observed. The observation revealed the softening temperature was 800-840C and the melting point was 840-850C, which was 10-20C lower than the TG-DTA results. The thermodynamics calculation of FactSage 7.2 revealed the temperature of the onset of melting was caused by melting of the some components such as Na
SiO
and/or Na
SiO. Moreover, the thermal conductivity was 
=1-3W/m-K, which was comparable to xNaO-1-xSiO (x=0.5, 0.33, 0.25), and those at 700C were explained by the equation of 
.
Ohno, Shuji; Matsuki, Takuo*
JNC TN9400 2000-106, 132 Pages, 2000/12
Sodium fire analyses were performed on 7 kinds of sodium leak tests using a computer code ASSCOPS which has been developed to evaluate thermal consequences of sodium leak accident in an FBR plant. By the comparison between the calculated and the test results of gas pressure, gas temperature, sodium catch pan temperature, wall temperature, and of oxygen concentration, it was confirmed that the ASSCOPS code and the parameters used in the analysis give valid or conservative results on thermal consequences of sodium leak and fire.
; Miyake, Osamu;
PNC TN9410 98-037, 81 Pages, 1998/04
The sodium combustion computer code ASSCOPS has been developed for analyses of thermal consequences (i.e.pressure and temperature time histories) of sodium leak accidents in FBR plants. Version 2.0 of ASSCOPS, that is used in the study of this report, includes improvements and additional models over the previous versions. This report describes the validation of ASSCOPS (version 2.0) by using sodium pool combustion tests data obtained from FAUNA (F5, F6) at KfK, Germany, and SOLFA-1 (Run-D1) at PNC. The validation includes comparisons of calculation results of ASSCOPS (Version 2.0) with experimental data, and with calculation results of the previous version of ASSCOPS (Version 1.1). Furthermore, the effects of reaction products ratio (NaO:NaO), initial humidity in the atomsphere, and radiation coefficient from the sodium pool to the gas were studied. The following results have been obtained from the study. (1)The calculation results agree well with the experimental data of the gas, sodium, and structure temperatures, and gas pressures. (2)The reaction products ratio (NaO:NaO) is one of the most important parameters for sodium combustion evaluation. It affects the pressure and temperature due to the difference of the reaction heat. Selection of proper value for this parameter results in the best estimate of the pressure, temperature and oxygen concentration. The ratio of NaO: NaO = 60: 40 is adequate for the purpose of conservative evaluation. (The analysis under the oxygen concentration below 10 % assumes NaO: NaO = 100: 0) (3)Initial humidity concentration in the air has been more little affect to the pressure and temperature than the reaction products ratio or the radiation coefficient of pool surface affect. (4)The radiation coefficient of pool surface was surveyed around the value obtained by conventional evaluation. The results shows that suppression of radiative heat transfer ...
; ; Tanabe, Hiromi; Ohno, Shuji; Miyake, Osamu;
PNC TN9410 97-030, 93 Pages, 1997/04
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.
Nagai, Keiichi; Saito, Junichi; Ara, Kuniaki
no journal, ,
no abstracts in English
Nagai, Keiichi; Saito, Junichi; Ara, Kuniaki
no journal, ,
no abstracts in English
Umeda, Ryota; Kurihara, Akikazu; Kikuchi, Shin; Kikuchi, Norihiro; Takata, Takashi; Ohshima, Hiroyuki
no journal, ,
Multi-level, multi-scenario simulation systems have been developed as safety fundamental technology for sodium-cooled fast reactors. In this report, as part of the verification and validation of the sodium fire analysis codes, in order to grasp the transport behavior of combustion generated aerosol during of sodium leak, the results of the transport behavior experiment using simulated particles is presented.
Umeda, Ryota; Kikuchi, Norihiro; Kurihara, Akikazu; Kikuchi, Shin; Takata, Takashi; Ohshima, Hiroyuki
no journal, ,
Multi-level, multi-scenario simulation systems as safety fundamental technology for sodium-cooled fast reactors (SFRs) has been developed. In this report, in order to understand the aerosol transport behavior in case of sodium fire, the experiment using multi-cell facility connected with horizontal or vertical pipe was performed as part of V&V for sodium fire analysis code.
Kikuchi, Norihiro; Umeda, Ryota; Kikuchi, Shin; Kurihara, Akikazu; Takata, Takashi; Ohshima, Hiroyuki
no journal, ,
Multi-level, multi-scenario simulation systems as safety fundamental technology for sodium-cooled fast reactors (SFRs) has been developed. In this report, in order to understand the aerosol transport behavior in case of sodium fire, the numerical simulation of experiment on aerosol transport behavior in multi-cell facility connected with horizontal or vertical pipe was performed as part of V&V for sodium fire analysis code.
