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Journal Articles

A Natural attenuation of arsenic in drainage from an abandoned arsenic mine dump

Fukushi, Keisuke*; Sasaki, Miwa*; Sato, Tsutomu*; Yanase, Nobuyuki; Amano, Hikaru; Ikeda, Hodaka*

Applied Geochemistry, 18(8), p.1267 - 1278, 2003/08

 Times Cited Count:220 Percentile:95.9(Geochemistry & Geophysics)

At Nishinomaki abandoned mine district, the water is acidic and contains much amounts of arsenic. However, arsenic concentration decreases downward without any artificial treatment. To understand the mechanism of the natural attenuation, the acid mine drainage and the ochreous precipitates were collected. The samples were analyzed by XRD, IR, ICP-MS and ion-chromatograph. The precipitates were investigated by selective extraction procedure. These results were interpreted with those calculated by the geochemical code. The contamination of water has been result from oxidation of pyrite and realgar and subsequent release of iron. The released ferrous iron transforms to ferric form by bacterial oxidation and then schwertmannite forms immediately. While the arsenic concentrations in the stream are lowered to background level at downstream, these in the ochreous precipitates are up to 60 mg/g. The iron hydroxide has been known to exhibit the high sorption affinity to arsenate. Hence, arsenic is effectively removed by the schwertmannite from the contaminated water and attenuated naturally.

JAEA Reports

Manufacture history results of an investigation of the bitumen solidification object towards the check of an abandonment object

; Kondo, Toshiyuki; *

JNC TN8440 2001-024, 210 Pages, 2001/08

JNC-TN8440-2001-024.pdf:24.99MB

In order to make this book reflect in the investigation which turned the bitumen solidification object to maintenance of the abandonment object technical standard on condition of carrying out subterranean disposal in the future - solidification - it created for the purpose of utilizing as precious sources of information, such as a nuclide inventory in the living body, group-izing of the past campaign required for typical solidification object selection, and information offer at the time of disposal examination. A development operation history collected so that histories including the shift action in an institution of the formation of discharge reduction of the characteristic of solidification object manufacture outlines, such as composition of the process of an institution and a solidification object and a storage actual result, the contents of an examination of the past campaign, and the solidification object manufactured based on topics or radioactive iodine and radioactive carbon etc., such as the past contents of an examination / operation, may grasp comprehensively in creation, and it carried out as the composition stared the trend of future disposal fixedly. It was a period (for 16 years) until an bituminization demonstration facility processing institution will start a cold examination from April (Showa 57), 1982, and it starts a hot examination from May 4, it starts solidification processing technical development operation from october 6 and it results in the fire explosion accident on March 11 (Heisei 9), 1997, and low level radioactivity concentration waste fluid was processed 7,438 m$$^{3}$$, and 29,967 bitumen solidification objects were manufactured. According to the accident, it is necessary to hand it down to future generations with processing technology while the bitumen solidification object manufactured in 15 years although the bituminization demonstration facility processing institution came to close the mission holds information precious ...

JAEA Reports

None

*

JNC TN1400 2001-013, 70 Pages, 2001/08

JNC-TN1400-2001-013.pdf:5.13MB

no abstracts in English

JAEA Reports

Evaluation of operatinal condition in LWTF; Tests using technical scale equipment

; Murata, Eiichi*; Sawahata, Yoshikazu*; Saito, Akira*

JNC TN8430 2001-002, 43 Pages, 2001/02

JNC-TN8430-2001-002.pdf:1.98MB

Japan Nuclear Cycle Development Institute (JNC) is designing the Low level radioactive Waste Treatment Facility (LWTF) in the Tokai Reprocessing Plant (TRP). The low level liquid waste generated the TRP is separated salt (NaNO$$_{3}$$, etc) and radionuclide in liquid treatment process of LWTF. The process can get higher volume reduction than previous bituminization. Based on the engineering tests equal to the liquid treatment process of LWTF, the validity of operational condition in LWTF is evaluated. As the results, it is confirmed that all operational condition in the processes which is Iodine immobilization, Pre-filter filtration, Pre-treatment, Coprecipitation and Ultrafiltration are available.

JAEA Reports

Development of analytical method for plutonium in high active liquid waste solution by high performance spectrophotometry

Jitsukata, Shu*; *; ; ; Kurosawa, A.

JNC TN8410 2001-002, 66 Pages, 2000/12

JNC-TN8410-2001-002.pdf:2.03MB

It was required from IAEA to determine a small amount of plutonium in the high active liquid waste solutions (HALW) in the tokai reprocessing plant. High performance spectrophotometer (HPSP), which could be obtained lower detection limit than conventional spectrophotometer, is studied to be applied to the inspection and verification analysis by the IAEA. [Cold Test] Neodymium, showing an absorption peak near the absorption wavelength of plutonium (VI), was used as an alternative element to plutonium, in order to review the calculation method of the peak intensity. As a result, the three-point correction method was found to be simple and effective. [Hot Test] Plutonium nitrate solution was used the fundamental test of this method. Since the method is known to be influenced by acidity, suspended sludge and coexistent elements in a sample, each dependency was examined. It was found that measurement results varied about 14% at a nitric acid concentration of 2-4 mol/L. Sludge should be removed by filtration before the measurement. The effect of coexisting elements could be eliminated adjusting the optical balance between reference and sample beam intensity. In the case of measuring a low concentration plutonium solution sample, a ratio of the peak intensity to the background intensity (S/B ratio) is relatively small. Therefore a method should be improved the S/B ratio by analyzing the obtained spectra. Accumulated average method, moving average method and Fourier transform method was tested. The results showed that a combination of the accumulated average method and the moving average method was the optimum method for the purpose. Linearity of the calibration curve was found between 0-11 mgPu/L. Synthetic sample solution, which simulated the actual constituents of the HALW with plutonium showed a good linear relation at 0-11 mgPu/L. The detection limit for plutonium concentration was 0.07 mgPu/L. When the synthetic HALW solution containing plutonium was measured, the de

JAEA Reports

Detailed investigation on the environmental effects from the liquid effluent of JNC reprocessing plant (IV); (April, 1996$$sim$$March, 2000)

; Shinohara, Kunihiko; ; ; ; Isozaki, Tokuju; ; *

JNC TN8440 2000-003, 93 Pages, 2000/08

JNC-TN8440-2000-003.pdf:2.2MB

The investigation on the radioactivity concentration for gross beta, $$^{3}$$H and $$^{137}$$Cs in seawater collected around the discharge point had been performed in order to grasp the change of the activity level of the coastal seawater offshore the JNC Tokai Works from the low level liquid effluent of the reprocessing plant. After the investigation on the radioactivity in seawater during the hot examination, the detailed investigation on the environmental effects from the liquid effluent of JNC reprocessing plant has been performed since July 1978 on the basis of the request from Ibaraki prefecture as the full-scale operation of the reprocessing plant. Consequently, no increase of the radioactive concentration due to the discharged effluent has been observed. And also, as the result of the consideration to the investigation on the environmental effect from the liquid effluent throughout 22 years since 1978, no change of the radioactive concentration level in seawater was recognized.

JAEA Reports

Research on advanced system safety assessment procedures (III)

Suzuki, Kazuhiko*; *

JNC TJ8400 2000-052, 136 Pages, 2000/02

JNC-TJ8400-2000-052.pdf:4.16MB

Though HAZOP is recognized as the useful safety assessment method, it requires a labor-intensive and time-consuming process. So recently computer-aided HAZOP has been proposed. The research report in 1999 (PNC TJ1400 99-003) presented HAZOP system based on the plant component malfunctions basic models. By using this basic model, not only state malfunction of component but also the consequence to external circumstance can be assessed. G2, which is an excellent object-oriented developer tool in GUI (Graphical User Interface), was used as a tool for developing the system. By using the graphical editor in the system, the user can carry out HAZOP easily. The purpose of this research is to improve the ability of the HAZOP system to obtain a more detailed HAZOP results. HAZOP is carried out according to the fault propagation of component level and the one of plant level based on plant component malfunctions basic models. Furthermore, the HAZOP system which can do the cause and effect analysis in detail intended for the component which processes two or more materials is developed. It is possible to carry out HAZOP for various plants by newly adding material information to the knowledgebase. We have applied this system to the Nuclear Reprocessing Facilities to demonstrate the utilities of developing system.

Journal Articles

New hopes to radiation water-treatment technology

Arai, Hidehiko

Hoshasen To Sangyo, (82), p.22 - 25, 1999/06

no abstracts in English

Journal Articles

Future development of water treatment technology

Hashimoto, Shoji

Genshiryoku eye, 44(8), p.34 - 36, 1998/08

no abstracts in English

JAEA Reports

The ninth test run of Joule-Heated cylindrical electrode melter on an engineering scale (JCEM-E9); Research report on solidification of high-level liquid waste

; ; *; *; Masaki, Toshio; Kobayashi, Hiroaki; *

PNC TN8410 98-041, 185 Pages, 1998/02

PNC-TN8410-98-041.pdf:7.51MB

The 9$$^{th}$$ test of Joule-Heated Cylindrical Electrode Melter - Engineering Scale (JCEM-E9 Test) was carried out from June to July 1996, as a part of the development program on an advanced glass melter. The principal purpose of the test was to estimate the effect of noble metal on operation of the melter with simulated high-level liquid waste. Besides, we also evaluated the basic operational characteristics with corrosion of electrodes, qualities of produced glass etc. JCEM-E is an electric glass melter with an internal electrode and an external electrode in a subsidiary furnace. The internal electrode is a rod inserted in the center of external electrode that is a cylindrical tank. The glass is melted by conducting electric current through the molten glass between the internal and external electrodes. The subsidiary furnace is composed of multi-layer refractories inside a metallic casing and is equipped with the resistance heaters. Melting surface area is 0.35 m$$^{2}$$ that i8 approximately half of 0.66 m$$^{2}$$ of TVF melter. In the test, 13 batches of glass was produced and total weight of produced glass was 3663kg. As a result, The maximum processing rate of JCEM-E with simulated HLLW including noble metals was 4.20$$sim$$5.60kg/h, and decreased to less than 80 percent compared with JCEM-E8 Test with non-noble metals HLLW. It was considered that the decrease of the rate arose from concentration of current due to non-uniform distribution of noble metals in molten glass. Judging from the balance of feed and draining, and as a consequence of the observation inside the melter after the test, the draining of noble metals from the nozzle was good. As for the quality of glass produced in the test, properties of concern were comparable with those of standard glass of TVF.

JAEA Reports

None

*; *; *

PNC TJ6357 98-002, 43 Pages, 1998/02

PNC-TJ6357-98-002.pdf:1.09MB

None

Journal Articles

IAEA international symposium on radiation technology for conservation of the environment

Hashimoto, Shoji

Hoshasen To Sangyo, (77), p.42 - 45, 1998/00

no abstracts in English

JAEA Reports

None

Sugihara, Yoichiro*; Mukai, Katsuyuki*; Nunomiya, Ichiro*

PNC TJ6357 97-001, 40 Pages, 1997/03

PNC-TJ6357-97-001.pdf:1.52MB

None

JAEA Reports

None

Akiba, Kenichi*

PNC TJ1601 97-002, 79 Pages, 1997/03

PNC-TJ1601-97-002.pdf:1.35MB

None

JAEA Reports

None

; ; Nomura, Kazunori; Koyama, Tomozo; ;

PNC TN8410 96-258, 46 Pages, 1996/09

PNC-TN8410-96-258.pdf:1.91MB

None

JAEA Reports

None

; Numata, Koji; ; *; *; Hanawa, Eiji*; *

PNC TN8440 96-014, 24 Pages, 1996/04

PNC-TN8440-96-014.pdf:0.88MB

None

JAEA Reports

None

PNC TN8440 96-003, 22 Pages, 1996/02

PNC-TN8440-96-003.pdf:0.73MB

None

JAEA Reports

None

; Nemoto, Takeshi; Numata, Koji; ; *; *; Hanawa, Eiji*

PNC TN8440 95-019, 22 Pages, 1995/04

PNC-TN8440-95-019.pdf:0.83MB

None

61 (Records 1-20 displayed on this page)