Evaluation of decay heat value from high-level liquid waste; Data for safety assessment of partitioning process

Morita, Yasuji; Tsubata, Yasuhiro

JAEA-Data/Code 2019-015, 45 Pages, 2020/01

JAEA-Data-Code-2019-015.pdf:2.09MB

Decay heat from radioactive elements in high-level liquid waste (HLLW) and separated solutions in partitioning process was evaluated as a basic data for safety assessment of partitioning process. In the evaluation of HLLW from spent UO fuel burned-up to 45 GWd/t in light water reactor, decay heat value from fission products decreased as the cooling period become longer but heat from actinides, Am and Cm, was almost constant until 50-year cooling. Decay heat density in solutions of Am, Cm and rare earth elements and of Am and Cm without concentration for volume reduction does not exceed the heat density of HLLW, but the concentration should be required to minimize the scale of the partitioning process. Separated solution of Am and Cm must be concentrated to convert the two elements to a solid state to make fuel for transmutation, and the decay heat density of the concentrated solution of Am and Cm is 10 times higher compared with the Pu solution of same element concentration. Higher burn-up UO fuel and MOX fuel in light water reactor and minor-actinide-recycled MOX fuel in fast reactor were also considered and the evaluated decay heat was compared among the spent fuels.

Optimization of disposal method and scenario to reduce high level waste volume and repository footprint for HTGR

Fukaya, Yuji; Goto, Minoru; Ohashi, Hirofumi; Nishihara, Tetsuo; Tsubata, Yasuhiro; Matsumura, Tatsuro

Annals of Nuclear Energy, 116, p.224 - 234, 2018/06

AA2017-0381.pdf:0.87MB

https://doi.org/10.1016/j.anucene.2018.02.031

Optimization of disposal method and scenario to reduce volume of High Level Waste (HLW) and the footprint in a geological repository for High Temperature Gas-cooled Reactor (HTGR) has been performed. It was found that HTGR has great advantages to reducing HLW volume and its footprint, which are high burn-up, high thermal efficiency and pin-in-block type fuel, compared with those of LWR and has potential to reduce those more in the previous study. In this study, the scenario is optimized, and the geological repository layout is designed with the horizontal emplacement based on the KBS-3H concept instead of the vertical emplacement based on KBS-3V concept employed in the previous study. As a result, for direct disposal, the repository footprint can be reduced by 20 % by employing the horizontal without change of the scenario. By extending 40 years for cooling time before disposal, the footprint can be reduced by 50 %. For disposal with reprocessing, the number of canister generation can be reduced by 20 % by extending cooling time of 1.5 years between the discharge and reprocessing. The footprint per electricity generation can be reduced by 80 % by extending 40 years before disposal. Moreover, by employing four-group partitioning technology without transmutation, the footprint can be reduced by 90 % with cooling time of 150 years.

Status and future plan of research and development on partitioning and transmutation technology for long-lived nuclides in JAERI

Oigawa, Hiroyuki; Nishihara, Kenji; Minato, Kazuo; Kimura, Takaumi; Arai, Yasuo; Morita, Yasuji; Nakayama, Shinichi; Katakura, Junichi

JAERI-Review 2005-043, 193 Pages, 2005/09

JAERI-Review-2005-043.pdf:16.13MB

JAERI has been conducting research and development on partitioning and transmutation (P&T) technology for long-lived nuclides to develop the double-strata fuel cycle concept, in accordance with the Atomic Energy Commission's "Research and Development of Technologies for Partitioning and Transmutation of Long-lived Nuclides - Status and Evaluation Report" issued in 2000. The double-strata fuel cycle concept consists of four major processes: partitioning, fuel fabrication, transmutation, and fuel processing. The five-year achievement and future perspectives for the technology on these processes are presented in this report. It also provides an analytical study on impacts of introducing P&T technology on waste management, and on deployment of P&T for the future nuclear energy system.

R&D on nuclear transmutation, A; Partitioning of high-level radioactive waste

Morita, Yasuji

Genshikaku Kenkyu, 47(6), p.21 - 30, 2003/06

This paper describes the present state and future prospect of research and development on the separation of long-lived radionuclides from high-level waste (partitioning), which is indispensable for the transmutation of those nuclides. The main items described are composition of high-level waste, selection of elements to be separated, the purpose of partitioining, and development of partitioning process in JAERI.

Radioactive wastes generated from JAERI partitioning-transmutation cycle system

Nakayama, Shinichi; Morita, Yasuji; Nishihara, Kenji

Proceedings of International Conference on Back-End of the Fuel Cycle: From Research to Solutions (GLOBAL 2001) (CD-ROM), 6 Pages, 2001/09

Production of lower-level radioactive wastes, as well as the reduction in radioactivity of HLW, is an important performance indicator in assessing the viability of a partitioning-transmutation system. We have begun to identify the chemical compositions and to quantify the amounts of radioactive wastes that may be generated by JAERI's processes. Long-lived radionuclides such as C and Ni and spallation products of Pb-Bi coolants such as Po (10 Bq/yr) are added to the existing inventory of these nuclides that are generated in the current fuel cycle. Spent salts of KCl-LiCl, which is not generated from the current fuel cycle, will be introduced as a waste.

Radioactive wastes generated from double-strata nuclear fuel cycle for partitioning and transmutation

Nakayama, Shinichi; Morita, Yasuji; Nishihara, Kenji

KURRI-KR-57, p.55 - 62, 2000/11

no abstracts in English

Proceedings of the 4th NUCEF Seminar; 18 Feb. 2000, JAERI Tokai, Japan

4th NUCEF Seminar Working Group

JAERI-Conf 2000-012, 52 Pages, 2000/07

JAERI-Conf-2000-012.pdf:5.47MB

no abstracts in English

R&D on transmutation of long-lived nuclides

Mukaiyama, Takehiko

Mirai, (6), p.40 - 43, 1999/07

no abstracts in English

The First test of 4-group partitioning process with real high-level liquid waste

Morita, Yasuji; Yamaguchi, Isoo; ; *; Kubota, Masumitsu

Proc. of the Int. Conf. on Future Nuclear Systems (GLOBAL'99)(CD-ROM), 8 Pages, 1999/00

no abstracts in English

Development of partitioning method; Confirmation of behavior of technetium in 4-group partitioning process by small scale experiment

Morita, Yasuji; Mizoguchi, Kenichi*; Yamaguchi, Isoo; ; Kubota, Masumitsu

JAERI-Research 98-046, 18 Pages, 1998/08

JAERI-Research-98-046.pdf:1.01MB

no abstracts in English