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Shinohara, Kunihiko; Takeishi, Minoru; ; ; Mizutani, Tomoko
JNC TN8440 2001-019, 141 Pages, 2001/11
JNC-TN8440-2001-019.pdf:12.69MB
This report was written about the effluent control in JNC Tokai Works from 1
April 2000 to 31 March 2001. In this period, the quantities and concentrations of retroactivities in liquid waste from Tokai Works were under the discharge limits of "Safety Regulations for the Tokai Reprocessing Plant", "Safety Regulations for the Tokai Reprocessing Plant" and regulations of government.
Ito, Yasuhisa; Noda, Kimio; ;
JNC TN8410 2001-018, 67 Pages, 2001/04
JNC-TN8410-2001-018.pdf:2.96MB
There are waste storage pits where non-radioactive wastes generated from plutonium fuel facilities were stored in JNC Tokai Works. But radioactive wastes were found in one of the pit during wastes arrangement works. Therefore we set the pit temporary controlled area and recovered wastes from it. This report describes the radiation control technique of recovery work in detail.
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.
Maruo, Yoshihiro; ; ;
JNC TN8440 2001-001, 135 Pages, 2000/12
JNC-TN8440-2001-001.pdf:4.61MB
None
Noda, Kimio; Shinohara, Kunihiko; Kanamori, Masashi
JNC TN8410 2001-010, 35 Pages, 2000/10
JNC-TN8410-2001-010.pdf:3.85MB
We, the radiation control section of JNC have had two important experiences on the JCO critical accident and the JNC fire-explosion accident. Especially, at the critical accident in JCO, it was essential to take an action on the radiation protection activities for the evacuated neighboring inhabitants to the safety area. During the accident, we carried out the radiation protection activities, at the beginning of the accident, environmental monitoring of the surrounding area. Especially for the JCO accident, we took an action to terminate criticality, radiation shielding and monitoring, environmental monitoring, radiation survey of the residents, radiation monitoring of exhaust air.
Miyabe, Kenjiro; Takasaki, Koji; Yasunaga, Hideo*; Izumi, Yuichi*
JNC TN8420 2000-007, 100 Pages, 2000/08
JNC-TN8420-2000-007.pdf:7.66MB
The commercial detergents, which are cleansing cream, shampoo, neutral detergent, etc., were examined in order to select the body cleaners that are substitutes for the titanium dioxide paste. JNC entrusted Japan Environment Research Corporation Limited with these examinations since 1997. In 1997 and 1998, the commercial detergents were examined for Ce-144, Cs-137 and Ru-106. In 1999, 22 detergents were examined for Co-60 from the result of the past examinations. In this examination, the radioactive solution of Co-60 was dropped on the pig-skin samples. These samples were washed with each detergent after 5 minutes and 40 minutes. The decontamination factors of detergents were estimated by the radioactive ratio of the samples before and after washing. As a result of this examination, the decontamination factors for Co-60 was the same as the decontamination factors for Ce-144 and Cs-137, and 11 detergents were nominated as the cleaner that have the decontamination factor more than that of titanium dioxide paste.
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
C, 700C, 800C), 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 700C failed in the tube. The weld zones had not failed. (b)The test specimens at 800C 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 (700C) 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.
Mochiji, Toshiro;
JNC TN1200 2000-001, 13 Pages, 2000/03
JNC-TN1200-2000-001.pdf:2.94MB
no abstracts in English
Yamasaki, Shinichi*
JNC TJ8430 2000-005, 159 Pages, 2000/03
JNC-TJ8430-2000-005.pdf:3.95MB
no abstracts in English
*; *
JNC TJ1400 2000-008, 82 Pages, 2000/03
JNC-TJ1400-2000-008.pdf:3.05MB
no abstracts in English
; Kano, Yutaka; ; Shindo, Katsutoshi
JNC TN9410 2000-001, 20 Pages, 1999/12
JNC-TN9410-2000-001.pdf:1.84MB
The 12th periodic inspection had been executed at the experimental fast reactor JOYO from February 24,1998 to June 28,1999. This inspection had been extended about three months because it was addtion to the work for the safety countermeasure. The result of collective dose equivalent was 263.92 man*mSv, whereas, the expected collective dose equivalent was about 407 man*mSv in the whole period of this inspection. It was confirmed that this inspection was carried out with the suitable radiation protection programmes. In this report, provided in 12th periodic inspection, were described with taking the results of the past periodic inspections into consideration.