Experiences from the cutting of metallic blocks from simulant Fukushima Daiichi fuel debris

Journeau, C.*; Molina, D.*; Brackx, E.*; Berlemont, R.*; Tsubota, Yoichi

Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR2022) (Internet), 5 Pages, 2022/10

CEA has manufactured a series of Fukushima Daiichi fuel debris simulants, either with depleted uranium oxide or with hafnium oxide as a surrogate of UO. In ex-vessel compositions resulting from an interaction between corium and concrete, the oxidic phase density becomes lighter than that of the metallic phase, which segregates at the bottom. Three of these metallic phases have been mechanically cut at CEA Cadarache with handsaw and with core boring tool in FUJISAN facility. It appeared that two of these metallic blocks were extremely hard to cut (one from a fabrication with uranium oxide, the other from a simulant block) while the last one was more easily cut. The similarities and differences in metallographic analyses (SEM-EDS and XRD) of these three metal blocks will be presented and discussed. This experience provides useful learnings in view of the cutting and retrieval of fuel debris from Fukushima Daiichi.

Comparative study on neutronics characteristics of a 1500 MWe metal fuel sodium-cooled fast reactor

Ohgama, Kazuya; Aliberti, G.*; Stauff, N. E.*; Oki, Shigeo; Kim, T. K.*

Mechanical Engineering Journal (Internet), 4(3), p.16-00592_1 - 16-00592_9, 2017/06

http://doi.org/10.1299/mej.16-00592

Tradeoff analysis of metal-fueled fast reactor design concepts

Stauff, N. E.*; Ohgama, Kazuya; Aliberti, G.*; Oki, Shigeo; Kim, T. K.*

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 10 Pages, 2017/04

Comparative study on neutronics characteristics of a 1500 MWe metal fuel sodium-cooled fast reactor

Ohgama, Kazuya; Aliberti, G.*; Stauff, N. E.*; Oki, Shigeo; Kim, T. K.*

Proceedings of 24th International Conference on Nuclear Engineering (ICONE-24) (DVD-ROM), 6 Pages, 2016/06

https://doi.org/10.1115/ICONE24-60455

Under the cooperative effort of the Civil Nuclear Energy R&D Working Group within the framework of the U.S.-Japan bilateral, Argonne National Laboratory (ANL) and Japan Atomic Energy Agency (JAEA) have been performing benchmark study using Japan Sodium-cooled Fast Reactor (JSFR) design with metal fuel. In this benchmark study, core characteristic parameters at the beginning of cycle were evaluated by the best estimate deterministic and stochastic methodologies of ANL and JAEA. The results obtained by both institutions are agreed well with less than 200 pcm of discrepancy on the neutron multiplication factor, and less than 3% of discrepancy on the sodium void reactivity, Doppler reactivity, and control rod worth. The results by the stochastic and deterministic were compared in each party to investigate impacts of the deterministic approximation and to understand potential variations in the results due to different calculation methodologies employed. Impacts of the nuclear data libraries were also investigated using a sensitivity analysis methodology.

Neutronic study on seed-blanket type reduced-moderation water reactor fuel assembly

Shelley, A.; Kugo, Teruhiko; Shimada, Shoichiro*; Okubo, Tsutomu; Iwamura, Takamichi

JAERI-Research 2004-002, 47 Pages, 2004/03

JAERI-Research-2004-002.pdf:3.08MB

Neutronic study has been done for a PWR-type reduced-moderation water reactor with seed-blanket fuel assemblies to achieve a high conversion ratio, a negative void coefficient and a high burnup by using a MOX fuel. The results of the precise assembly burnup calculations show that the recommended numbers of seed and blanket layers are 15(S15) and 5(B5), respectively. By the optimization of axial configuration, the S15B5 assembly with the seed of 10002 mm high, internal blanket of 150 mm high and axial blanket of 4002 mm high is recommended. In this configuration, the conversion ratio is 1.0 and the core average burnup is 38 GWd/t. The S15B5 assembly can attain the core average burnup of 45 GWd/t by decreasing the height of seed to 5002 mm, however, the conversion ratio becomes 0.97. The void and fuel temperature coefficients are negative for both of the configurations. Effect of metal or T-MOX (PuO+ThO) fuel has been also investigated. Metal improves the conversion ratio but makes the void coefficient worse. T-MOX improves the void coefficient, but decreases the conversion ratio.

Modeling of fuel performance and fission product release behaviour during HTTR normal operation; A Comparative study on the FZJ and JAERI Modeling approach

Verfondern, K.*; Sumita, Junya; Ueta, Shohei; Sawa, Kazuhiro

JAERI-Research 2000-067, 127 Pages, 2001/03

JAERI-Research-2000-067.pdf:6.64MB

no abstracts in English

Measurement test on creep strain rate of uranium-zirconium solid solutions

*; Akabori, Mitsuo; Ogawa, Toru

JAERI-Tech 96-052, 18 Pages, 1996/11

JAERI-Tech-96-052.pdf:0.92MB

no abstracts in English

Verification of fission product release model from High Temperature Engineering Test Reactor fuel

Sawa, Kazuhiro; Shiozawa, Shusaku; Fukuda, Kosaku;

Journal of Nuclear Science and Technology, 29(9), p.842 - 850, 1992/09

https://doi.org/10.3327/jnst.29.842

no abstracts in English

Core design study for hybrid type trans-uranium nuclides incineration plant, Part 1; Concept

Takada, Hiroshi; Kanno, Ikuo; Takizuka, Takakazu; Akabori, Mitsuo; ; Kaneko, Yoshihiko

JAERI-M 90-131, 18 Pages, 1990/08

JAERI-M-90-131.pdf:0.59MB

no abstracts in English

Fuel elements and fuel cycle concepts of actinide burner reactors; Conceptual study of actinide burner reacotors, IV

Ogawa, Toru; Mukaiyama, Takehiko; Takano, Hideki; Takizuka, Takakazu; ; *

JAERI-M 89-123, 38 Pages, 1989/09

JAERI-M-89-123.pdf:1.25MB

no abstracts in English