Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Takeishi, Minoru; Shibamichi, Masaru; Malins, A.; Kurikami, Hiroshi; Murakami, Mitsuhiro*; Saegusa, Jun; Yoneya, Masayuki
Journal of Environmental Radioactivity, 177, p.1 - 12, 2017/10
By convention radiation measurements from vehicle-borne surveys are converted to the dose rate at 1 m above the ground in the absence of the vehicle. To improve the accuracy of the converted results from vehicle-borne surveys, we investigated combining measurements from two detectors mounted on the vehicle at different heights above the ground. A dual-detector setup was added to a JAEA monitoring car and compared against hand-held survey meter measurements in Fukushima Prefecture. The dose rates obtained by combining measurements from two detectors were within 
20% of the hand-held reference measurements. The combined results from the two detectors were more accurate than those from either the roof-mounted detector, or the detector inside the vehicle, taken alone. When radiocesium is deficient on a road compared to the adjacent land, mounting detectors high on vehicles yields dose rates closer to the values adjacent to the road. We also investigated mounting heights for vehicle-borne detectors using Monte Carlo 
-ray simulations.
Yoneya, Masayuki; Sanada, Yukihisa
Nihon Genshiryoku Gakkai-Shi ATOMO
, 57(8), p.517 - 522, 2015/08
no abstracts in English
; ; Koakutsu, Masayuki; ; Miyamoto, Yasuaki; Takeda, Seiichiro
Saikuru Kiko Giho, (16), 37- Pages, 2002/00
None
Takahashi, Kuniaki; Takeda, Seiichiro; ; ;
Spectrum2000, 0 Pages, 2000/00
None
Shigetome, Yoshiaki; ;
JNC TN8410 99-035, 62 Pages, 1999/12
The bituminization demonstration facility (BDF) of Tokai reprocessing plant had a fire and explosion incident. Thermal analysis of simulated bituminized products was conducted to investigate the chemical behavior of them. This analysis detected no activating factors which enhance chemical heat reactions. According to the operators' observation, filling temperature of the bituminization product rose to an unusually high temperature before the incident. The overheating effect on the bituminized product was investigated by 'keeping high temperature' test. Hollows and brittle material were generated in the products after the heating. This state is similar to the actual state of the products processed in the BDF from 28 to 29 batch.
;
JNC TN8410 99-036, 113 Pages, 1999/09
The fire and explosion incident occurred at Bituminization Demonstration Facility of PNC Tokai Works on March 11, 1997. In order to ascertain the cause of incident, the investigation has been pushed forward. For the investigation, we prepared simulated bituminized product for measurement of heat generation in low temperature region less than 200 
C. We used calvet Calorimeter MS80 for the heat generation measurement. Result of measurement, We were able to catch the feeble heat generation from bituminized product. The maximum calorific value that was able to detect it in isothermal measurement was approximately 1 mW /g in 160 C. It was approximately 2 mW /g in 200 C. And, as the another measurement, the measurement condition went heat rate by 0.01 C/minute, the highest temperature 190 C. As a result, the maximum generation of heat value that was able to detect it was approximately 0.5 mW /g. I changed simulated bituminized products and measured these. A difference of condition is salt particle size, salt content rate (45%, 60%), addition of the simulated precipitate. But there was not a difference in the generation of heat characteristic detected.
; Shibata, Atsuhiro; ; ; Koyama, Tomozo
JNC TN8410 99-033, 87 Pages, 1999/08
In the investigation of bituminization demonstration facility incident, oxidation reaction of bituminized products with air was considered to be one of the potential causes for the fire incident. In this study, the possibility for the proceeding of the oxidation reaction in bituminized products was investigated with the fundamental data which were obtained from the study on the oxidation reaction in simulated bituminized products by infrared (IR) absorption measurements. The results of IR analysis during the oxidation reaction in the simulated bituminized products showed that functional groups with the oxygen generated mainly under non-air atmosphere, but the dehydrogenation reaction proceeded simultaneously under air atmosphere. It was also recognized that the change of absorption peaks assigned to cyanides in the simulated bituminized products under the non-air atmosphere was different from that under the air atmosphere. The results of IR measurements for the bituminized products in filling room indicated that the oxidation reaction (generation of the functional groups with the oxygen) was occurred more furiously in the bituminized products made at around 29B than that in the normal operation. They also showed a very little contribution of dehydrogenation reaction and the changes of peaks assigned to the cyanides in the bituminized products. These suggest that the oxidation reaction of the bituminized products in the filling room might proceed under the non-air atmosphere.
; Koyama, Tomozo; Maki, Akira; Yamanouchi, Takamichi
Proceedings of International Conference on Future Nuclear Systems (GLOBAL '99) (CD-ROM), 0 Pages, 1999/08
None
Miyamoto, Yoichi; Kawamura, Kazuhiro; Yoneya, Masayuki; Kobayashi, Aoi
PNC TN8410 98-119, 79 Pages, 1998/07
None
Kawamura, Kazuhiro; Yamana, Satoshi; Kobayashi, Hiroaki;
PNC TN8440 98-006, 184 Pages, 1998/02
None
; Koyama, Tomozo; Maki, Akira; Yamanouchi, Takamichi
7th International Conference on Radioacti, 0 Pages, 1998/00
None
; Miyamoto, Yoichi; Akiba, Kenichi*
Solvent Extraction and Ion Exchange, 16(4), p.1013 - 1031, 1998/00
None
; Miyamoto, Yoichi; Akiba, Kenichi*
Solvent Extraction and Ion Exchange, 16(4), p.1013 - 1031, 1998/00
Times Cited Count：24 Percentile：69.73(Chemistry, Multidisciplinary)None
Shibata, Atsuhiro; ; ; Koyama, Tomozo
PNC TN8410 98-015, 92 Pages, 1997/12
Operational records in the bituminization demonstration facility in 97-M46-1 campaign were analyzed in order to investigate the cause of fire. Operational records which are different from ordinary level in this campaign are drum weight, temperature at 7th zone and extruder torque. So we investigated past campaign data about these records. The results are as follows. (1)In some campaigns, drum weight was lighter, temperature at 7th zone higher, and torque higher. (2)When drum weight is lighter, temperature at 7th zone becomes relatively higher. (3)In the case that higher temperature was measured at 7th zone, drum weight was sometimes less than the past average. (4)When the extruder's torque increases, it sometimes influences drum weight and temperature at 7th zone. The mixture of salt and bitumen became hotter from 28 B. As the heat source, both frictional resistance and exothermic chemical reaction can be considered. Frictional resistance came out with increase of the torque. So we checked some operational parameters to investigate what increases the torque. Feed rate of waste solution is related with the torque increase. The other parameters are not related with it. Now we can not specify any causes of the torque increase from 27B, the feed rate of waste solution is however possible to be one of the causes.
; Aoyama, Makoto; ; Yamanouchi, Takamichi
PNC TN8410 97-319, 143 Pages, 1997/10
The fire and explosion incident occurred at Bituminization Demonstration Facility of PNC Tokai Works on March 11, 1997. In order to ascertain the cause of incident, the investigation has been pushed forward. During investigation, we obtained essential information from operators, such as softness of bituminized product, white smoke generated from bituminized product. This condition has never been observed comparing past normal operation. Therefore, we assumed that temperature of bituminized product had increased more than expected. In order to confirm above assumption, we made experiment for obtaining the relationship between temperature and fluidity of bituminized product. Simulated bituminized product was heated up to each temperature (210, 230, 250, 270C) in a pot and poured down into an another pot. We observed the fluidity of bituminized product when it flowing down into a pot. The fluidity of bituminized product increased with high temperature. The fluidity of bituminized product at 270C looked similar to fluidity of bituminized product that had ignited itself at the incident. White smoke generated from bituminized product and amounts of white smoke increased with high temperature. The smoke was considered to be gas that generated through thermal decomposition or volatilization of bitumen.
; ; ; ; Miyamoto, Yoichi
Proceedings of International Conference on Future Nuclear Systems (GLOBAL'97), 0 Pages, 1997/00
None
; ; Kawamura, Kazuhiro; ; Miyamoto, Yoichi
Proceedings of International Conference on Future Nuclear Systems (Global'97), Vol.2, p.1501 - 1503, 1997/00
None
; Kawamura, Kazuhiro; ; Sasage, Kenichi; ; Ouchi, Jin
Donen Giho, (98), p.85 - 90, 1996/06
None
