JOPSS - Search Results

Journal Articles

Simulation study of sludge precipitation in spent fuel reprocessing

Takeuchi, Masayuki; Aihara, Haruka; Nakahara, Masaumi; Tanaka, Kotaro*

Procedia Chemistry, 21, p.182 - 189, 2016/12

https://doi.org/10.1016/j.proche.2016.10.026

Times Cited Count：1 Percentile：27.38

A simulation technology with electrolyte thermodynamic model has been developed to evaluate the precipitation behavior in reprocessing solution based on nitric acid solution. The simulation results were compared with the experiment data from non-radioactive simulated HLLW with ten elements and Pu-Zr-Mo solution, and the reliability of the thermodynamic model was verified. Most of the precipitation species was zirconium molybdate hydrate from the both data. It is demonstrated that the chemical species and amount of the precipitation calculated by thermodynamic model reflected well that of experiments. This study has shown the thermodynamic simulation model is one of the useful tools to estimate the behavior of precipitation from the reprocessing solution.

Journal Articles

Development of paper sludge ash-based geopolymer and application to treatment of hazardous water contaminated with radioisotopes

Li, Z.*; Onuki, Toshihiko; Ikeda, Ko*

Materials, 9(8), p.633_1 - 633_17, 2016/08

https://doi.org/10.3390/ma9080633

Times Cited Count：15 Percentile：38.11(Chemistry, Physical)

Geopolymer samples were prepared at room temperature using paper sludge ashes and immobilization of Sr and Cs in these samples were evaluated by short-term leaching test. The prepared geopolymer samples were semi-crystalline and porous. For the leaching test, the geopolymer samples containing 1 weight % of strontium nitrate or cesium nitrate were prepared, crushed to be finer than 4 mm in size, and immersed in a phthalic salt buffer (pH4) for 6 h. About 0.2% of Sr and 1.3% of Cs were leached from the geopolymer samples.

Journal Articles

Sludge behavior in centrifugal contactor operation for nuclear fuel reprocessing

Sakamoto, Atsushi; Sano, Yuichi; Takeuchi, Masayuki; Okamura, Nobuo; Koizumi, Kenji

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 5 Pages, 2015/05

Journal Articles

The Evaluation of graft-adsorbent for removal of uranium from waste sludge

Seko, Noriaki; Tamada, Masao; Yoshii, Fumio

Nippon Genshiryoku Gakkai Wabun Rombunshi, 3(4), p.340 - 345, 2004/12

https://doi.org/10.3327/taesj2002.3.340

Fibrous adsorbents having chelate agent such as amidoxime (AN/MAA-ad), iminodiacetic acid (IDA-ad), and phosphoric acid (HMPA-ad) were prepared by radiation-induced graft polymerization. AN/MAA-ad was synthesized by co-grafting of acrylonitrile and methacrylic acid. Then the introduced functional group of CN was converted to the amidoxime with chemical treatment. Grafting of glycidyl methacrylate and chemically introducing the IDA group synthesized IDA-ad. HMPA-ad was directly synthesized by grafting of phosphoric acid monomer. The densities of the chelate agency were 3.5 mol/kg for AN/MAA-ad, 2.0 mol/kg for IDA-ad and 2.0 mol/kg for HMPA-ad after the grafting time of 2, 1.5 and 8 hours, respectively. HMPA-ad had 200 times higher distribution coefficient for uranium than that of a commercial adsorbent (Diaion-PK216) at pH 0.5. The distribution coefficient for AN/MAA-ad became 500 times higher than that of Diaion-CR11 more than pH 8. These chelate adsorbents are promising materials for removal of uranium from acid or alkali treated waste sludge contaminated uranium.

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

None

; ; ; Hayashi, Shinichiro; ;

PNC-TN8410 96-055, 147 Pages, 1996/02

PNC-TN8410-96-055.pdf:5.2MB

None

JAEA Reports

None

Numata, Koji; ; Nemoto, Takeshi;

PNC-TN8430 93-001, 37 Pages, 1993/04

PNC-TN8430-93-001.pdf:0.34MB

None

JAEA Reports

None

PNC-TN1700 93-002, 64 Pages, 1993/01

PNC-TN1700-93-002.pdf:0.91MB

no abstracts in English

JAEA Reports

Performance test using modified (6000rpm type) centrifugal clarifier (III); Vibration characteristic test (II)

; ;

PNC-TN8410 92-012, 47 Pages, 1991/12

PNC-TN8410-92-012.pdf:1.81MB

[Purpose] We confirmed that modified (6000rpm type) centrifugal clarifier arose the unstable vibration during the reduction of rotating speed under the condition of bearing undissolved residue after the clarification operation. This report describes the cause of unstable vibration that arise in the clarification body set on the rack which induced resonance vibration and the measurement results of vibration characteristic after taking countermeasure for vibration decrease. [Method] It was considered that the causes of the unstable vibration were following; (1)Unbalance between damping force of the lower bearing damper and the vibration force arisen by the rotational bowl (2)Effect of feed condition (3)Effect of self-excited vibration of the free liquid surface (4)Effect of frame strength The test has been conducted to make quantitative measure of vibration characteristic (amplitude of the rotational bowl and shaft) by changing the load in the rotational bowl. We also conducted the test to reconfirm the effect of the circumferential baffle plate which has shown the most effective effect to the vibration decrease in the preceding report. [Results] The effects of the circumferential baffle plate placed on the inside wall of the rotational bowl are shown as follows; (1)The unstable vibration during the reduction of rotating speed has been suppressed By this result, we verified that the vibration on the free liquid surface in the rotational bowl caused the vibration for the bowl without the circumferential baffle plate. (2)It was able to run the clarification operation in the standard condition(100/h 6h) for the rotational speed ranging from 4000 to 6000rpm. [Conclusion] By the results of this test and of the preceding report, the feed condition and the condition of setting the circumferential baffle plate are showed in the following, considering the aspects of rotational stability. (1)Condition of feed nozzle - feed 55㎜ in height from the lower ...