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Koarashi, Jun; Mikami, Satoshi; Miyauchi, Toru; Kozawa, Tomoyasu*; Yokota, Tomokazu*; Nakada, Akira; Akiyama, Kiyomitsu; Momose, Takumaro
JAEA-Technology 2010-039, 34 Pages, 2010/12
The current methodology for monitoring airborne radioiodine at the Tokai reprocessing plant (TRP) was reviewed, and some investigations were made to re-evaluate collection and measurement techniques in the methodology. The investigations focused particularly on: (1) in situ collection efficiency of an iodine sampler for I and its dependence on sampling flow rate; (2) evaluation of
I and
I activities collected in an activated charcoal cartridge; (3)
I collection capacity of an activated charcoal cartridge under reprocessing off-gas conditions; and (4) real-time monitoring system for
I in airborne effluent. The results obtained gave not only the validity of the TRP's monitoring method, but also technical aspects required for establishing a more reliable and effective monitoring method for radioiodine isotopes.
Nakada, Akira; Miyauchi, Toru; Akiyama, Kiyomitsu; Momose, Takumaro; Kozawa, Tomoyasu*; Yokota, Tomokazu*; Otomo, Hiroyuki*
JAEA-Data/Code 2008-018, 134 Pages, 2008/10
This report provides the data set of atmospheric discharges from Tokai reprocessing plant in Tokai-mura, Japan over the period from 1998 to 2007. Daily and weekly data are shown for Kr that is continuously monitored and for the other nuclide (Alpha emitters, Beta emitters,
H,
C,
I,
I) whose activities are evaluated based on weekly batch-samplings, respectively. The data contained in this report are expected to apply for studying the behavior of the radioactive airborne effluent in the environment.
Koarashi, Jun; Isaka, Keisuke*; Yokota, Tomokazu*; Kozawa, Tomoyasu*; Mikami, Satoshi; Akiyama, Kiyomitsu; Kobayashi, Hirohide
JNC TN8410 2005-005, 55 Pages, 2005/05
Some investigations were made for re-evaluating collection and measurement techniques in an airborne C discharge monitoring at the Tokai reprocessing plant (TRP), which include (1)collection efficiency of CO
in a carbon sampler using monoethanolamine as CO
absorbent;(2)affect of incorporating tritiated water into the carbon sampler on quantitative estimation of
C activity in airborne effluent; (3)affect of leakage in air sampling on evaluating airborne
C discharge; and (4)determination of chemical forms of
C in airborne release from the TRP. The results presented not only the validity of the TRP's monitoring method, but also the technical aspects required for establishing a more reliable and effective monitoring method.
Koarashi, Jun; Yokota, Tomokazu*; Kozawa, Tomoyasu*; Isaka, Keisuke*; Mikami, Satoshi; Akiyama, Kiyomitsu; Kobayashi, Hirohide
JNC TN8410 2005-004, 73 Pages, 2005/05
Some investigations were made for re-evaluating collection and measurement techniques in an airborn H discharge monitoring at the Tokai reprocessing plant (TRP), which include (1)collection efficiency of water in a tritium sampler; (2)quench correction in
H activity measurement by liquid scintillation counting; (3)affect of leakage in air sampling on evaluating airborne
H discharge; and (4)determination of chemical forms of
H in airborne release from the TRP. The results presented not only the validity of the TRP's monitoring method, but also the technical aspects required for establishing a more reliable and effective monitoring method.
Koarashi, Jun; Akiyama, Kiyomitsu; Asano, Tomohiro; Yokota, Tomokazu*
Journal of Radioanalytical and Nuclear Chemistry, 262(3), p.771 - 774, 2005/01
Effect of incorporating tritiated water into a C sampling system on sample preparation and
C activity measurement by liquid scintillation counting were investigated. Experiments derived the limit of water content in prepared sample, and also demonstrated that
C activity can be determined without any interference from
H contamination for clear-solution sample. The results enabled us to estimate permissible reelative humidity of air required for accomplishing sample preparation and
C activity measurement. These showed that for sampling of air with less than the permissible relative humidity, total
C activity in airborne effluent can be evaluated accurately with no dehumidification of air.
Koarashi, Jun; Kozawa, Tomoyasu*; Yokota, Tomokazu*; Isaka, Keisuke*; Akiyama, Kiyomitsu; Asano, Tomohiro
JNC TN8410 2004-003, 49 Pages, 2004/07
Radioactive airborne effluent discharged from Tokai reprocessing plant (TRP) contains tritium, carbon-14 and radioiodine. These radionuclides are collected with appropriate methods, respectively, in stacks to monitor their concentrations and discharged amounts. This report describes (1) the methods for collecting these radionuclides in TRP; (2) evaluations of the concentrations and discharged amounts; and (3) investigations on estimating performances of the collecting methods. The investigations showed that the collecting methods used in TRP have collecting efficiencies of more than 90% for tritium and radioiodine, and almost 100% for carbon-14. Considerations concerning collection of radionuclides in airborne effluent, made in this study, provided some technical aspects required for establishing more reliable monitoring systems.
Koarashi, Jun; Yokota, Tomokazu*
JNC TN8450 2004-003, 8 Pages, 2004/05
This report summarizes the amount of Kr-85 discharge in the air from Tokai Reprocessing Plant (2002-2003).
Ishida, Junichiro; ; ; ; Akiyama, Kiyomitsu; ; Tanaka, Hiroshi; ; Kurimata, Tomoyuki*; Ozawa, Tomoyasu*; et al.
JNC TN8410 98-002, 112 Pages, 1998/09
None
Miyauchi, Toru; Koarashi, Jun; Mikami, Satoshi; Kozawa, Tomoyasu*; Yokota, Tomokazu*; Isaka, Keisuke*; Akiyama, Kiyomitsu
no journal, ,
no abstracts in English
Mikami, Satoshi; Miyauchi, Toru; Koarashi, Jun; Kozawa, Tomoyasu*; Yokota, Tomokazu*; Isaka, Keisuke*; Akiyama, Kiyomitsu
no journal, ,
no abstracts in English
Ito, Yasuhisa; Mikami, Satoshi; Miyauchi, Toru; Akiyama, Kiyomitsu; Kobayashi, Hirohide; Kozawa, Tomoyasu*; Yokota, Tomokazu*
no journal, ,
no abstracts in English