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Hoshiba, Hideaki; Hashimoto, Makoto; Irokawa, H.; Usui, Toshihide; Sato, Hayato; Emori, Shuichi
JNC TN9410 2004-017, 170 Pages, 2004/08
JNC-TN9410-2004-017.pdf:18.93MB
While the JOYO MK-III Project, after the modification of primary coolant system started in oct.2000 and the integrated function tests, from Jun.2003, the performance test was executed for the purpose of verification of designed performance and confirmation of basic characteristics as an irradiation reactor. While the JOYO MK-III performance test, 28 tests were executed. Radiation control section took charge of 3 of them, "Dose Rate Distribution", "Radiation Control" and "Gaseous Waste Radioactive Concentration Measurement". The performance tests in charge of radiation control section was started on Jun.27, 2003, that is before the start-up of reactor, and were carried out when the thermal output of reactor was 40MWt, 70MWt, 105MWt and effective full power, 140MWt. The pre-operation tests in charge of radiation control section are "Test of dose rate measurement in operation and after shutdown". "Test of radioactive concentration measurement of air", and "Test of gaseous waste processing performance". The final test was "Test of dose rate measurement after shutdown", which was executed on Nov.27 2003. JOYO passed the inspection and the performance test was finished. The representative results in these performance tests are; 1.Every result is under the criterion 2.Dose rate and monitoring data are totally less than the data in MK-II operation. Though it confirmed that all the data are under the criterion, it is considered that these tests should be performed at proper intervals because the circumstances may change.
Kano, Yutaka; Hoshiba, Hideaki; Emori, Shuichi; Higuchi, Tsunehisa
JNC TN9410 2004-012, 51 Pages, 2004/03
JNC-TN9410-2004-012.pdf:2.98MB
The 13th annual inspection at the experimental fast reactor JOYO had been executed from June 1, 2000 to November 27, 2003. While this inspection,in addition to the regular maintenance and repair, some countermeasure works based on safety overhaul and works relevant to the heat transport system modification for upgrading the irradiation performance (MK-III modfication) in the under floor of reactor building were implemented. Duration of the inspection was about 3.5 years, longer than past inspections. While the inspection, the replacement of the internal heat exchanger (IHX) A, B, in primary coolant system, and relevant pipes was considered important in radiation control. The point of radiation control of this work was external exposure to workers.The expectation of exposure dose in the annual inspection and the MK-III modification were made for every work subject in consideration of procedure, number of workers, period and place of the work. The expectation of total exposure in the annual inspection, summed up the yearly expectation from 2000 to 2003, was 1156 man-mSv. While In the MK-III modification from June 1, 2000 to November 30, 2002, the expectation of total exposure was 7135 man-mSv. Furthermore, all the while in the MK-III modification, We call for work end department that workers exposure was as low as practical. As a result, total exposure was 633 man-mSv in the annual inspection, and 2386 man-mSv in the MK-III modification. Both of total result exposure was about 30-50% of the expectation, and every worker's exposure were controlled under the criteria of exposure control. Finally, the works in the 13th annuall inspection was properly executed.
Hashimoto, Tomoharu; Hashimoto, Makoto; Ishikawa, Masayasu; Emori, Shuichi
Hoken Butsuri, 39(3), 229- Pages, 2004/00
It was executed that the investigation on the performance of dosimeters for individual monitoring which compare present TLD with recently dosimeters, OSL, Glass dosimeter, EPD, SSTD. It also surveyed operating method of each dosimeter.
Hashimoto, Tomoharu; Ishikawa, Masayasu; Emori, Shuichi
JNC TN9420 2003-001, 50 Pages, 2003/09
JNC-TN9420-2003-001.pdf:1.93MB
We investigate the new tipe dosimeter to prepare for renewal of the present TLD in the near future.As a result of investigation, if we pursue the rationalization and convenience in the operation of dosimeter more and more, then we will recommend the electric pocket dosimeter positively.
Kano, Yutaka; ; ; *; Hoshiba, Hideaki; ; Shindo, Katsutoshi
JNC TN9410 2002-009, 127 Pages, 2002/03
JNC-TN9410-2002-009.pdf:10.69MB
The 13th periodical inspection of the experimental fast reactor JOYO is being made from Jun. 2000 to Jan. 2003. While this inspection, from the end of oct. 2000 to Nov. 2001, the MK-III modification work on heat transport system was made in lower region of the reactor containment vessel in the reactor facility (under floor area). In the MK-III modification work, the works important to radiation control were the replacement of intermediate heat exchangers (IHxs) and fixtures, and the picking out of the surveillance material from primary heat transport piping carried out in the maintenance building. Because the working areas of these works were executed in small space around the complicated primary heat transport piping, workability was bad and dose rate from the corrosion products (CP) in piping or fixtures was high. In such condition, radiation control was performed mainly concerned about external exposure. The planned total external exposure of the IHX replacement and related works was 7135 man
mSv (target of total dose control: less than 5708 manmSv, 80% of the plan), derived from special radiation work plans for segmental works, concerned about work procedure, number of workers, period of work, dose rate of working area and surface dose rate of equipments. The special radiation control organization was established for such long and large-scale work. The special organization held detailed discussion about radiation control of this work with the execution section and contractors appropriately, performed carefal external/internal exposure control and surface contamination control and made effects to reduce the external exposure thoroughly. As a result of these action, the total external exposure was 2386 manmSv ( 
33% of the plan, 42% of the target) and the maximum individual exposure were 24.7 mSv for staffs and 21.7 mSv for contractors. The dose rate, surface contamination and air contamination while the works were ...
; 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.
Aoyama, Takafumi; Suzuki, Toshiaki; Takatsuto, Hiroshi; Oowada, Toshio; Oyama, Nobumi; Emori, Shuichi
PNC TN9418 97-006, 93 Pages, 1997/12
non
Aoyama, Takafumi; ; Suzuki, Toshiaki; ; ; Emori, Shuichi
Donen Giho, (104), p.3 - 93, 1997/12
None
; ; ; Ando, Hideki
PNC TN9410 97-094, 27 Pages, 1997/10
The 11th periodic inspection had been executed at the experimental fast reactor JOYO from May 10,1995 to March 24,1997. Because the inspection had been extended several times, the time span of external exposure control was divided into two period. The result of collective dose equivalent in the previous term(from May 10,1995 to December 7,1996: about seventeen months) was 243.34 man*mSv, whereas, the expected collective dose equivalent was about 280man*mSv. The result of collective dose equivalent in the latter term (from December 8,1996 to March 24,1997: about three months) was 44.73 man*mSv, whereas, the expected collective dose equivalent was about 85man*mSv. The collective dose equivalent in the whole period of this inspection was 288.07 man*mSv. It was confirmed that this inspection was carried out with the suitable radiation protection programmes. In this report, the method for the control of external exposure and the reduction of external exposure, provided in 11th periodic inspection, were described with taking the results of the past periodic inspections into consideration.
Emoto, Takehiko; Torii, Tatsuo; Nozaki, Tatsuo; Saito, Kei; Emori, Shuichi; Ando, Hideki
PNC TN9410 96-299, 74 Pages, 1996/08
The technique has been developed to measure the dose-rate distribution of radiation easily. The detector is made of plastic scintillation fibers (of following PSFs). The technique is based on the time of flight method, that is to measure the time difference of scintillation reaching from a incidence position to both ends of fibers. Measuring devices were built as trials. The position resolution was measured with collimated 
ray. The dose-rate linearity and the energy response were measured with an irradiation equipment of ray. Then, the devices were applied to the dose-rate distribution measurements in facilities. The tests were carried out to turn the technique into practicable use. Main results are as follows; (1) The continuos dose-rate distribution of ray can be measured with a single detector. The result of a measurement is illustrated on the screen of a device immediately. (2) The upper limit of counting rate measuring range is 10
cps. The upper limit of ray dose-rate measuring range is 1 mSv/h (calculated value) for a detector of "0.25 mm 
1 peace, 10 m length". (3) The detection efficiency does not depend on the ray energy between 500 keV and 1.5 MeV. (4) The practical length of PSFs is up to about 10 m for the dose-rate distribution measurement. (5) When the dose-rate distribution has sharp peaks, the output distribution of measurement is slightly flattened against the actual distribution based on the detector characteristic of position resolution. The unfolding method can correct this effect. (6) It is possible to discriminate the energy and type of radiation, if the pulse height output of a photomultiplire is corrected in each incidence position with the multi-parameter measuring method.
Takashima, Hideki; Iwasa, Atsutoshi; Eguchi, Kazutoshi; Yoshimochi, Hiroshi; Obayashi, Hiroshi; Emori, Shuichi
no journal, ,
In Alpha- Facility (AGF),Japan Atomic Energy Agency Oarai, the situation of the existing nuclide composition ratio etc. has changed greatly by manufacturing of the Am content mixed oxide fuel and executing the characteristic test. Therefore, the nuclide composition ratio etc. concerned were measuring analyzed, and the radiation management method in the emergency was examined as a result. As for the analysis sample, it gathered in the cell and the glove box (17 places) in facility, and the nuclide composition ratio was evaluated from the measurement result of the mass spectrometry etc. As a result, the nuclide composition approximated to the MA fuel pellet was seen of many sample and the difference was seen in the nuclide composition of each sample (especially, Am-241, Pu-239, and Pu-240). The result of the radiation management method in the emergency becomes as follows from these. (1) It is possible to execute immediately the initial assessment of internal expose from these data obtained this time and all alpha radioactivity that can be measured comparatively promptly by the presumption evaluation of radioactivities of each nuclides such as Pu and Am on the accident generation place. (2) If happened an abnormal discharge and the air contamination etc. of A radioactive substance, the originating place and the nuclide composition can be presumed by evaluating the radioactivity of Am-241 and all alpha radioactivity that can be measured comparatively promptly.
-ray spectrometerSaito, Kei; Takashima, Hideki; Emori, Shuichi; Soma, Susumu; Takada, Chie
no journal, ,
no abstracts in English
Usui, Toshihide; Takashima, Hideki; Saito, Kei; Tagawa, Hiroshi; Ito, Kimio; Emori, Shuichi
no journal, ,
no abstracts in English
