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Kato, Tomoko; ; Suzuki, Yuji*; ; Ishiguro, Katsuhiko; Ikeda, Takao*; Richard, L.*
JNC TN8400 2001-003, 128 Pages, 2001/03
JNC-TN8400-2001-003.pdf:6.09MB
In the safety assessment of a high-level radioactive waste (HLW) disposal system, it is required to estimate radiological impacts on future human beings arising from potential radionuclide releases from a deep repository into the surface environment. In order to estimate the impacts, a biosphere model is developed by reasonably assuming radionuclide migration processes in the surface environment and relevant human lifestyles. Releases from the repository might not occur for many thousands of years after disposal. Over such timescales, it is anticipated that the considerable climatic change, for example, induced by the next glaciation period expected to occur in around ten thousand years from now, will have a significant influence on the near surface environment and associated human lifestyles. In case of taking these evolution effects into account in modeling, it is reasonable to develop several alternative models on biosphere evolution systems consistent with possible future conditions affected by expected climatic changes. In this study, alternative biosphere models were developed taking effects of possible climatie change into account. In the modeling, different climatic states existing in the world from the present climate condition in Japan are utilized as an analogy. Estimation of net effects of the climatic change on biosphere system was made by comparing these alternative biosphere models with a constant biosphere model consistent with the present climatic state through flux to dose conversion factors derived from each one.
Kakehi, Isao; Nakabayashi, Hiroki
JNC TN9400 2000-051, 237 Pages, 2000/04
JNC-TN9400-2000-051.pdf:8.14MB
In this study, we have proposed the concept of safety systems (solutions of safety problems) in pyrochemical reprocessing systems (lt consists of pyrochemical reprocessing methods and the injection casting process for the metal fuel fabrication, or vibro-packing process for the oxide fuel fabrication.) which has different concept from the existing PUREX reprocessing method and pellet fuel fabrication process. And we performed its safety evaluations. FoIlowing the present Japanese safety regulations for reprocessing facilities, we pointed out functions, design requirements and equipments relating to its safety systems and picked up subjects. For the survey of safety evaluations, we first selected anticipated events and accident events, and second by evaluated 6the correspondence of the limitation of the public exposure to the accidents above, by using two parameters, the safety design parameter (the filter performance to confine radioactive matelials) and the leak inventory of radioactivities, and last by picked up its problems. ln addition to the above evaluations we performed basic criticality analyses for its systems to utilize these results for the design and evaluation of the criticality safety management system. Thus this study specified the concept of safety systems for pyrochemical reprocessing processes and then issues in order to establish safety design policies (matters which must consider for the safety design) and guides and to advance more definite safety design.
*; *
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.
Tsujimura, Norio; Shinohara, Kunihiko; Momose, Takumaro
PNC TN8510 98-001, 13 Pages, 1998/07
None
Tsujimura, Norio; Shinohara, Kunihiko; Momose, Takumaro
PNC TN8410 98-083, 20 Pages, 1998/05
None
Ishibashi, Yuzo; Kuroda, Yoshikatsu*; Nakajima, Atsushi*
PNC TJ8216 98-003, 243 Pages, 1998/03
no abstracts in English
; ; ; 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.
Tsujimura, Norio; Shinohara, Kunihiko; Momose, Takumaro
PNC TN8410 97-207, 25 Pages, 1997/06
None
Sato, Satoshi; Takatsu, Hideyuki; *; *; Mori, Seiji*; Iida, Hiromasa; R.Santoro*
Journal of Fusion Energy, 16(3), p.211 - 218, 1997/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
Tsujimura, Norio; ; Komatsuzaki, Kenji; Momose, Takumaro; Shinohara, Kunihiko
PNC TN8410 97-002, 40 Pages, 1996/12
None
Tsujimura, Norio; Momose, Takumaro; Shinohara, Kunihiko
PNC TN8410 96-402, 90 Pages, 1996/12
None
Sumino, Kozo; Aoyama, Takafumi; Nagai, Akinori
PNC TN9410 96-216, 85 Pages, 1996/07
The cover gas radioactivity in the reactor vessel increases when a fuel pin failure occurs or RTCB (Run to Cladding Breach) testing is performed. The activity must be reduced to minimize the personnel exposure and to maintain the reserve capacity of the waste gas system in which the residual fission gas is stored. The CGCS (Cover Gas Cleanup System) was installed in the JOYO primary cover gas system to collect and remove the fission gas. The cryogenic charcoal bed cooled by the liquid nitrogen selectively adsorbs the krypton and xenon due to the adsorption ratio difference. The collection ratio for xenon and krypton was measured using fission gas in the fuel failure simulation test and a standard helium diluted non-radioactive gas. As a result, the collection ratio was confirmed to be more than 90% for xenon and more than 80% for krypton by six hours operation of CGCS. It was confirmed that the CGCS has a capability to remove the fission gas effectively.
Tsujimura, Norio; Momose, Takumaro; Shinohara, Kunihiko
PNC TN8410 96-211, 37 Pages, 1996/07
None
Amano, Hikaru
JAERI-Research 96-029, 190 Pages, 1996/06
JAERI-Research-96-029.pdf:5.55MB
no abstracts in English
