JOPSS - Search Results

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

Times Cited Count：26 Percentile：75.01(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.

JAEA Reports

Improvement of the technique for stack monitoring based on behavior analysis of natural radio-nuclides; The technique for reducing the value of the exhaust monitor's background

Izaki, Kenji; Noda, Kimio; ; Kashimuta, Yoshio*

JNC TN8410 2001-005, 30 Pages, 2001/01

JNC-TN8410-2001-005.pdf:0.62MB

Stack monitoring is the most important work in radiation control works. Exhaust monitors used for stack monitoring have the background (which is the counts by natural radio-nuclides) on normal condition, and the values of the background vary with the facilities. Therefore, if the value of background is high, it is difficult to estimate rapidly the radioactive concentration in the exhaust. In order to estimate rapidly the radioactive concentration in exhaust, we analyzed the behavior of natural radioactivity in the facilities and examine the technique fo reducing the value of the background. As a result of the examination, we found that it is possible to estimate rapidly if we change over the monitoring point to immediately after the HEPA filters on the exhaust duct. In this reports, the analyzed results of behavior of natural radio-nuclides in the facilities and the technique for reducing the values of the background are described. To reduce the value of the background has a major effect on not only rapidly estimating the radioactive density in the exhaust but also finding the unusual things on stack monitoring.

Journal Articles

A Mathematical foundation of controlling radiation health risks

Kumazawa, Shigeru

Proceedings of 10th International Congress of the International Radiation Protection Association (IRPA-10) (CD-ROM), 12 Pages, 2000/05

no abstracts in English

JAEA Reports

Study on reducing the generation of general waste

Aoki, Isao; ; Haga, Tetsuya; ; Sudo, Katsuo; Tsunashima, Yasumichi;

JNC TN8420 2000-005, 42 Pages, 2000/04

JNC-TN8420-2000-005.pdf:2.09MB

On August 1999, the Director of Tokai Work proposed an activity regarding recycling and reuse of general waste generated from Tokai Works. The activity was initiated by the Waste Management and Fuel Cycle Research Center, and is now being in progress through out the Tokai Works. In the course of this activity, Plutonium Fuel Center had settled the Working Group and the issues related to the waste reduction have been examined. This report collects the problems that became obvious through the survey of existing segregation method, treatment process, and the amount of the waste generation, and accounts for the concrete methodology for the recycling and reuse of general waste. In order to reduce waste, it is necessary to aware of the facing issues and adopt the countermeasures proposed in this report whenever possible. The activity will then leads us to reduce waste generation, which in turn will enable us to make 100 % waste recycling possible.

JAEA Reports

Development of resistance welding process; Manufacture of test specimens for ODS steel strength evaluation

Endo, Hideo; Seki, Masayuki; ; *; *

JNC TN8410 2000-007, 89 Pages, 2000/03

JNC-TN8410-2000-007.pdf:6.28MB

(1)Outline of examination. Various test specimens were made to evaluate and confirm the weld strength properties of the oxide dispersion strengthened (ODS) cladding tube material (martensitic and ferritic steel), which had been manufactured in JFY 1997. The examination consisted of tensile tests (RT,650 $^{circ}$ C, 700 $^{circ}$ C, 800 $^{circ}$ C), internal pressure creep tests, internal pressure burst tests, and a rapid heating burst tests. (2)Examination results. The results of the tensile tests are as follows: (ferritic and martensitic) (a)All test specimens from RT to 700 $^{circ}$ C failed in the tube. The weld zones had not failed. (b)The test specimens at 800 $^{circ}$ C failed in the weld zones. There was little elongation. (ferritic) (a)The weld zone had fine grain structure and carbide precipitates. (martensitic) (a)Carbide had precipitated in the weld zone. From these results, the strength of weld zone decreased extremely at temperatures exceeding the endurance limit (700 $^{circ}$ C) All of the internal pressure burst test specimens and the rapid heating burst test specimens failed in the tube and not the weld zone. (3)The quality assurance method of the test specimens. The weld reliability of the test specimens were confirmed by the process control of the welding conditions, by using control test specimens, and ultrasonic testing. Confirmation of the process control of the welding conditions; current wave, the voltage waveform, the accelerogram, and the displacement ripple in the welding process was recorded to assure an abnormal value had not occurred. (Process control of welding condition) The results the current waveform, voltage waveform, accelerogram, and the displacement waveform were excellent. (test specimens) The weld joint was excellent based on metallography examination. (Ultrasonic testing) The length of the weld joint was measured and found to be adequate. The reliability the weld joint can be assured by using the above-mentioned method.