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Kubo, Yoshikazu*; Hayashi, Katsunori*
JNC TJ8430 2005-001, 61 Pages, 2005/03
JNC-TJ8430-2005-001.pdf:1.77MB
In the low-level radioactive waste treatment technology development facility(LWTF),the cement solidification process is being studied on its applicability as a method for preparing waste packages from sodium-nitrate-containing low-level liquid waste generated at reprocessing plants.Solidified products prepared by the use of this process contain nitrate(sodium nitrate)and nitrite(sodium nitrite), and such products might come under the category of the Class1 Hazardous Material(oxidative solid)under the Fire Services Act.Thus it has been determined that cement-solidified products prepared from simulated liquid waste will be tested to judge whether they should be treated as
Kubo, Yoshikazu*; Sasaki, Tadashi*
JNC TJ8430 2005-003, 91 Pages, 2005/02
JNC-TJ8430-2005-003.pdf:0.64MB
In the low level radioactive waste treatment facility (LWTF), the cement solidification process is being studied on its applicability as a method for preparing waste packages from sodium-nitrate-containing low-level liquid waste generated at reprocessing plants. Solidification of nitrate solution waste: Solidification in a high temperature caused a rapid hydration reaction of cement, resulting in rapid hardening during the mixing process and a drop in fluidity. However, it has been confirmed that liquid waste can be solidified at 80
C or so by adding a dispersing agent to improve fluidity and changing the amount of hardening solution to be added for cement hardening. This has verified that the cement solidification process under contemplation is applicable to nitrate-containing liquid waste. Solidification of slurry waste: In solidifying slurry waste, a fall in fluidity and a fall in compressive strength were observed. It is considered that this is attributed to the effects of phosphate contained in the liquid waste. In the case of slurry waste whose phosphate concentration is adjusted to 0g/L, it has been verified that solidified products whose salt mixing ratio is 50wt% can be prepared when the liquid waste temperature is 80C and the degree of concentration is 65wt%. It has been revealed that increases in the NaNO
, NaHCO
, and NaSO
contents cause a delay in cement hardening, a fall in compressive strength, and a fall in fluidity, respectively. It has also been revealed that when liquid waste containing phosphate alone is solidified, solidified products whose salt mixing ratio is 50wt% in terms of hydrate salt (NaPO 8HO) (26.6wt% in terms of anhydrate salt) can be prepared.
Oyamada, Kiyoshi*; Ikeda, Takao*
JNC TJ8400 2004-007, 100 Pages, 2004/02
JNC-TJ8400-2004-007.pdf:3.89MB
This report presents results on trial study of methodology to identify Geosphere-Biosphere Interface (GBI), and examination in consideration of overseas trend of long-term biosphere assessment.
Oyamada, Kiyoshi*; Ikeda, Takao*
JNC TJ8400 2004-006, 199 Pages, 2004/02
JNC-TJ8400-2004-006.pdf:8.87MB
This report presents results on trial study of methodology to identify Geosphere-biosphere Interface (GBI), and examination in consideration of overseas trend of long-term biosphere assessment.
Oyamada, Kiyoshi*; Ikeda, Takao*
JNC TJ8400 2003-096, 53 Pages, 2004/02
JNC-TJ8400-2003-096.pdf:0.72MB
This study developed minute estimation by adopting comprehensive sensitivity analytical program for reliability of TRU waste repository concepts in a crystalline rock condition. We examined each components and groundwater scenario of geological repository and prepared systematic bases to examine the reliability from the point of comprehensiveness. Models and date are sophisticated to examine the reliability. Based on an existing TRU waste repository concepts, effects of parameters to nuclide migration were quantitatively classified. Those parameters, that will be decided quantitatively, are such as site character of natural barrier and design specification of engineered barriers. Considering the feasibility of those figures of specifications, reliability is re-examined on combinations of those parameters within a practical range. Future issues are ; (1)Comprehensive representation of hybrid geosphere model including the fractured medium and permeable matrix medium. (2)Sophistication of tools to develop the reliable combinations of parameters. It is significant to continue this study because the disposal concepts and specification of TRU nuclides containing waste on various sites shall be determined rationally and safely through these studies.
Oyamada, Kiyoshi*; Ikeda, Takao*
JNC TJ8400 2003-095, 243 Pages, 2004/02
JNC-TJ8400-2003-095.pdf:4.06MB
This study developed minute estimation by adopting comprehensive sensitivity analytical program for reliability of TRU waste repository concepts in a crystalline rock condition. We examined each components and groundwater scenario of geological repository and prepared systematic bases to examine the reliability from the point of comprehensiveness. Models and date are sophisticated to examine the reliability. Based on an existing TRU waste repository concepts, effects of parameters to nuclide migration were quantitatively classified. Those parameters, that will be decided quantitatively, are such as site character of natural barrier and design specification of engineered barriers. Considering the feasibility of those figures of specifications, reliability is re-examined on combinations of those parameters within a practical range. Future issues are ; (1)Comprehensive representation of hybrid geosphere model including the fractured medium and permeable matrix medium. (2)Sophistication of tools to develop the reliable combinations of parameters. It is significant to continue this study because the disposal concepts and specification of TRU nuclides containing waste on various sites shall be determined rationally and safely through these studies.
*; *; *; *
JNC TJ8430 2002-002, 61 Pages, 2003/02
JNC-TJ8430-2002-002.pdf:1.41MB
no abstracts in English
Miki, Takahito*; Oyamada, Kiyoshi*; Ikeda, Takao*
JNC TJ8400 2003-054, 45 Pages, 2003/02
JNC-TJ8400-2003-054.pdf:0.44MB
This study developed analytical programs and procedures based on a method of stochastic radionuclide migration to estimate the feasibility of disposal concepts and to define design specifications, considering the variety of scenarios and disposal concepts divided by depth of repository for TRU nuclides containing waste.
Miki, Takahito*; Oyamada, Kiyoshi*; Ikeda, Takao*
JNC TJ8400 2003-053, 386 Pages, 2003/02
JNC-TJ8400-2003-053.pdf:10.69MB
This study developed analytical programs and procedures based on a method of stochastic radionuclide migration to estimate the feasibility of disposal concepts and to define design specifications, considering the variety of scenarios and disposal concepts divided by depth of repository for TRU nuclides containing waste.
Kobayashi, Wataru*; Nakagawa, Tatsuo*; Mukunoki, Atsushi*; Goto, Kikuji*
JNC TJ8400 2003-044, 85 Pages, 2003/02
JNC-TJ8400-2003-044.pdf:1.47MB
Radioisotopes, nuclear fuel materials, and so on have been used in the various fields such as the research activities of universities and research institutes or the treatment and diagnosis of the medical institutes. It is necessary to treat and dispose of radioactive wastes safely and economically. A fundamental examination was carried out in the Conceptual Design Phase I of Disposal Facility below the generally used Depth for RI Laboratory Wastes and so on in last year. Based on the latest wastes data, the reevaluation of the facility design and the safety evaluation were enforced toward the examination result in last year. And it was examined about the operation procedure that includes wastes reception and disposal place closing. Furthermore, economic evaluation about the disposal was enforced.
Kobayashi, Wataru*; Nakagawa, Tatsuo*; Mukunoki, Atsushi*; Goto, Kikuji*
JNC TJ8400 2003-043, 168 Pages, 2003/02
JNC-TJ8400-2003-043.pdf:4.08MB
Radioisotopes, nuclear fuel materials, and so on have been used in the various fields such as the research activities of universities and research institutes or the treatment and diagnosis of the medical institutes. It is necessary to treat and dispose of radioactive wastes safely and economically. A fundamental examination was carried out in the Conceptual Design Phase I of Disposal Facility below the generally used Depth for RI Laboratory Wastes and so on in last year. Based on the latest wastes data, the reevaluation of the facility design and the safety evaluation were enforced toward the examination result in last year. And it was examined about the operation procedure that includes wastes reception and disposal place closing. Furthermore, economic evaluation about the disposal was enforced.
Miki, Takahito*; Ikeda, Takao*
JNC TJ8400 2003-018, 64 Pages, 2003/02
JNC-TJ8400-2003-018.pdf:1.01MB
This report contains results on study of method of identification of Geosphere-Biosphere Interface (GBI), toxicological impact of non-radioactive contaminants contained in radioactive waste disposal facility and consideration of climate change in long-ter
Miki, Takahito*; Ikeda, Takao*
JNC TJ8400 2003-017, 342 Pages, 2003/02
JNC-TJ8400-2003-017.pdf:5.64MB
This report contains results on study of method of identification of Geosphere-Biosphere Interface (GBI), toxicological impact of non-radioactive contaminants contained in radioactive waste disposal facility and consideration of climate change in long-ter
Miki, Takahito*
JNC TJ8400 2002-057, 54 Pages, 2002/02
JNC-TJ8400-2002-057.pdf:0.73MB
In this report, feasibility studies for mid-depth disposal of wastes solidified by asphalt, plastic and ROBE which are generated from JNC's Tokai reprocessing plant were carried out. In this study, at first, the characteristics of those wastes were summarized. And FEPs (Features, Events and Processes) regarding safety assessment for mid-depth disposal system were reviewed. Next, stochastic simulations were conducted to clarify the enough conditions in system specification for achieving a target which is well below the dose criteria for groundwater scenarios. Furthermore, important issues which affect disposal barrier systems were extracted using results of stochastic analysis and FEPs considerations. With regard to the environmental impacts of nitrate and boron which are included in the above wastes, literature survey and preliminary numerical analysis regarding flux and concentrations of them around disposal facility were carried out in order to discuss the feasibility. Finally, research programs for the improvement feasibility of mid-depth disposal of those wastes were developed.
Miki, Takahito*
JNC TJ8400 2002-056, 416 Pages, 2002/02
JNC-TJ8400-2002-056.pdf:16.57MB
In this report, feasibility studies for mid-depth disposal of wastes solidified by asphalt, plastic and ROBE which are generated from JNC's Tokai reprocessing plant were carried out. In this study, at first, the characteristics of those wastes were summarized. And FEPs (Features, Events and Processes) regarding safety assessment for mid-depth disposal system were reviewed. Next, stochastic simulations were conducted to clarify the enough conditions in system specification for achieving a target which is well below the dose criteria for groundwater scenarios. Furthermore, important issues which affect disposal barrier systems were extracted using results of stochastic analysis and FEPs considerations. With regard to the environmental impacts of nitrate and boron which are included in the above wastes, literature survey and preliminary numerical analysis regarding flux and concentrations of them around disposal facility were carried out in order to discuss the feasibility. Finally, research programs for the improvement feasibility of mid-depth disposal of those wastes were developed.
Miki, Takahito*; Oyamada, Kiyoshi*; Ikeda, Takao*
JNC TJ8400 2002-051, 40 Pages, 2002/02
JNC-TJ8400-2002-051.pdf:0.28MB
In this study, for the mid-depth disposal system for TRU wastes, asset of stochastic simulations covering uncertainties corresponding to variety of scenarios, models and parameter values were conducted to; (1)indicate measures to reduce potential exposure based on the knowledge of sensitivity structure (2)introduce new methodology for clarify the requirement of repository system (3)show guidelines of disposal system development by clarifying conditions in system specification for achieving a target which is well below the dose constraint for base scenarios (4)identify scenarios and conditions that could lead to a radiological impact greater than the dose constraint for alternative scenarios In the course of geological disposal for TRU waste, improvement of assessment methodology for the alternative scenarios was carried out.
Miki, Takahito*; Oyamada, Kiyoshi*; Ikeda, Takao*
JNC TJ8400 2002-050, 217 Pages, 2002/02
JNC-TJ8400-2002-050.pdf:2.66MB
In this study, for the mid-depth disposal system for TRU wastes, asset of stochastic simulations covering uncertainties corresponding to variety of scenarios, models and parameter values were conducted to; (1)indicate measures to reduce potential exposure based on the knowledge of sensitivity structure (2)introduce new methodology for clarify the requirement of repository system (3)show guidelines of disposal system development by clarifying conditions in system specification for achieving a target which is well below the dose constraint for base scenarios (4)identify scenarios and conditions that could lead to a radiological impact greater than the dose constraint for alternative scenarios In the course of geological disposal for TRU waste, improvement of assessment methodology for the alternative scenarios was carried out.
Miki, Takahito*; Yoshida, Hideji*; Ikeda, Takao*
JNC TJ8400 2002-010, 66 Pages, 2002/02
JNC-TJ8400-2002-010.pdf:1.45MB
This report contains results on study of Geosphere-Biosphere Interface (GBI), development of biosphere assessment model for gaseous and volatile radionuclides, review of biosphere assessment and research on safety indicators. Regarding study of Geosphere-Biosphere Interface (GBI), FEP database for the Geosphere-Biosphere Transitions Zone (GBTZ) were compiled. Furthermore, release scenarios were identified from the FEP database, and review of conservativeness and robustness of the conceptual and mathematical models developed previously by JNC were undertaken. Regarding development of biosphere assessment model for gaseous and volatile radionuclides, the conceptual and mathematical models were developed, and it was confirmed that the impact of the exposure pathway regarding gas release to flux-to-dose conversion factor is small. Regarding review of biosphere assessment data, the parameters which were used on JNC second progress report were reviewed and classified using the biosphere data protocol categories. Furthermore, the data for key parameter(important but poorly characterized parameters) were revised. Regarding research on safety indicator, some kinds of safety indicators, especially for the non-radioactive contaminant and for the non-human biota, are reviewed.
Miki, Takahito*; Yoshida, Hideji*; Ikeda, Takao*
JNC TJ8400 2002-009, 338 Pages, 2002/02
JNC-TJ8400-2002-009.pdf:8.57MB
This report contains results on study of Geosphere-Biosphere Interface (GBI), development of biosphere assessment model for gaseous and volatile radionuclides, review of biosphere assessment and research on safety indicators. Regarding study of Geosphere-Biosphere Interface (GBI), FEP database for the Geosphere-Biosphere Transitions Zone (GBTZ) were compiled. Furthermore, release scenarios were identified from the FEP database, and review of conservativeness and robustness of the conceptual and mathematical models developed previously by JNC were undertaken. Regarding development of biosphere assessment model for gaseous and volatile radionuclides, the conceptual and mathematical models were developed, and it was confirmed that the impact of the exposure pathway regarding gas release to flux-to-dose conversion factor is small. Regarding review of biosphere assessment data, the parameters which were used on JNC second progress report were reviewed and classified using the biosphere data protocol categories. Furthermore, the data for key parameter(important but poorly characterized parameters) were revised. Regarding research on safety indicator, some kinds of safety indicators, especially for the non-radioactive contaminant and for the non-human biota, are reviewed.
*; *; *; *
JNC TJ8400 2002-006, 178 Pages, 2001/02
JNC-TJ8400-2002-006.pdf:10.07MB
Radioisotopes, nuclear fuel materials, and so on have been used in the various fields such as the research activities of universities and research institutes or the treatment and diagnosis of the medical institutes. It is necessary to treat and dispose of radioactive wastes safely and economically. However, as for radioactive wastes disposal below the generally used depth, a concrete disposal concept isn't examined, and the safety of disposal isn't evaluated, either. This report contains building of the database for the radioactive wastes applicable for disposal below the generally used depth, and preliminary safety evaluation was enforced on the setup of condition presumed in the present. Finally subjects for the conceptual design of the disposal facility below the generally used depth were extracted.