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.

Reversible elastocaloric effect at ultra-low temperatures in nanocrystalline shape memory alloys

Ahadi, A.*; Kawasaki, Takuro; Harjo, S.; Ko, W.-S.*; Sun, Q. P.*; Tsuchiya, Koichi*

Acta Materialia, 165, p.109 - 117, 2019/02

https://doi.org/10.1016/j.actamat.2018.11.035

Structure of a highly acidic -lactamase from the moderate halophile sp.560 and the discovery of a Cs-selective binding site

Arai, Shigeki; Yonezawa, Yasushi*; Okazaki, Nobuo*; Matsumoto, Fumiko*; Shibazaki, Chie; Shimizu, Rumi; Yamada, Mitsugu*; Adachi, Motoyasu; Tamada, Taro; Kawamoto, Masahide*; et al.

Acta Crystallographica Section D, 71(3), p.541 - 554, 2015/03

https://doi.org/10.1107/S1399004714027734

The crystal structure of halophilic -lactamase from sp.560 (HaBLA) was determined using X-ray crystallography. Moreover, the locations of bound Sr and Cs ions were identified by anomalous X-ray diffraction. The location of one Cs specific binding site was identified on HaBLA even in the presence of 9-fold molar excess of Na (90 mM Na /10 mM Cs). This Cs binding site is formed by two main-chain O atoms and an aromatic ring of a side chain of Trp. An aromatic ring of Trp interacts with Cs by the cation- interaction. The observation of a selective and high-affinity Cs binding site provides important information that is useful for designing artificial Cs binding sites useful in bioremediation of radioactive isotopes.

Investigation of a model to evaluate the pyrolysis properties of zinc stearate

Abe, Hitoshi; Tashiro, Shinsuke; Miyoshi, Yoshinori

Nihon Genshiryoku Gakkai Wabun Rombunshi, 6(1), p.10 - 21, 2007/03

https://doi.org/10.3327/taesj.J05.028

In MOX fuel fabrication facility, zinc stearate will be added into the MOX powder as addition material. If the material is added in large excess by miss operation, criticality characteristics of the MOX fuel would be influenced because it has neutron moderation effect. If criticality condition should be induced by the excess addition, physical variations, such as melting and pyrolysis of the material, must be caused by the fission energy and dynamic characteristics of the MOX fuel must be affected. To contribute quantitative evaluation of the dynamic characteristics, thermal properties data such as exo/endothermic calorific values, reaction rates, etc. with the respective physical variations and release behavior of pyrolysis gas were measured. It was found the exo/endothermic behavior with rinsing temperature of the material could be divided into six regions and rapid pressure rise caused by the pyrolysis reaction over about 400 C. Furthermore, on the basis of the results, evaluation model for the thermal properties under the criticality condition was also investigated.

Heat capacities of technetium metal and technetium-ruthenium alloy

Shirasu, Yoshiro; Minato, Kazuo

Journal of Alloys and Compounds, 337(1-2), p.243 - 247, 2002/05

https://doi.org/10.1016/S0925-8388(01)01933-8

no abstracts in English

Enthalpy and heat capacity of (CaPu)TiO(x=0 and 0.20)

Sato, Tsuyoshi*; Yamazaki, Satoshi*; Yamashita, Toshiyuki; Matsui, Tsuneo*; Nagasaki, Takanori*

Journal of Nuclear Materials, 294(1-2), p.135 - 140, 2001/04

https://doi.org/10.1016/S0022-3115(01)00470-6

no abstracts in English

Improvement of tritium accountancy technology for the ITER fuel cycle safety enchancement

Ohira, Shigeru; Hayashi, Takumi; Nakamura, Hirofumi; Kobayashi, Kazuhiro; Tadokoro, Takahiro*; Nakamura, H.*; Ito, Takeshi*; Yamanishi, Toshihiko; Kawamura, Yoshinori; Iwai, Yasunori; et al.

Nuclear Fusion, 40(3Y), p.519 - 525, 2000/03

https://doi.org/10.1088/0029-5515/40/3Y/312

no abstracts in English

Numerical investigation on thermal striping conditions for a tee junction of LMFBR coolant pipes (IV); Investigation on second-order moments in coolant mixing region

JNC TN9400 2000-008, 323 Pages, 2000/02

JNC-TN9400-2000-008.pdf:25.2MB

This rport presents numerical results on theemal striping characteristics at a tee junction of LMFBR coolant pipe, carried out using a direct numerical simulation code DINUS-3. In the numerical investigations, it was considered a tee junction system consisted of a main pipe (1.33 cm) with a 90 elbow and a branch pipe, and four parameters, j.e., (1)diameter ratio between both the pipes, (2)flow velocity ratio between both the pipes, (3)angle between both the pipes, and (4)Reynolds number Re. From the numerical investigations, the following characteristics were obtained: (1)According to the decreasing of the diameter ratio, significant area of second-order moments was expanded in the fixed condition of =1.0. (2)Significant second-order moments area was expanded for the increasing of the flow velocity ratio specified by varying of the main pipe velocity in the case of a = 1.0 constant condition. 0n the other hand, the area was expanded for the decreasing of the velocity ratio defined by varying of the branch pipe velocity in the case of a = 3.0 constant condition. (3)Maximum second-order moments values were generated in the case of = 180 due to the influence of interactions between main pipe flows and jet flows from the branch pipe. (4)According to the increase of Reynolds number, significant area of second-order moments was expanded due to the activation of turbulence mixing in the main pipe.

Improvement of tritium accountancy technology for the ITER fuel cycle safety enhancement

Ohira, Shigeru; Hayashi, Takumi; Nakamura, Hirofumi; Kobayashi, Kazuhiro; Tadokoro, Takahiro*; Nakamura, H.*; Ito, Takeshi*; Yamanishi, Toshihiko; Kawamura, Yoshinori; Iwai, Yasunori; et al.

Fusion Energy 1998, 3, p.1069 - 1072, 1998/10

no abstracts in English

Thermal Fluid-Structure Interaction Analysis of ShieldPlug(II); Verification of FLUSH by Two-Dimensional Model

*;

PNC TN9410 96-102, 40 Pages, 1996/04

PNC-TN9410-96-102.pdf:0.91MB

In designing the shield plug of LMFBR, it is important to evaluate the thermal response between the cover gas thermal-hydraulics and the temperature fields of the shield plug at the same time. Based on the experiments which were performed by OEC, the natural convection and the thermal radiation in the cover gas layer were calculated with the structure simulating the shield plug in a detail two-dimensional model. The calculations were carried out for 8 kinds of experimental RUNs using a FLUSH code. The main results were as follows: (1)For these 8 kinds of experimental RUNs, the velocity and the temperature distributions in the cover gas layer were presented. The radial and axial temperature distributions in the rotating plug were also presented, which were difficult to measure by the experiments. (2)The boundary surface temperature between the cover gas layer and the rotating plug had the same tendencies and the calculated average temperatures on the boundary surface had good agreements with the experimental data. The average relative deviations from experimental values were less than 1.3%. (3)The natural convection of the cover gas enhanced the temperature distributions in the structure. The effects of thermal radiation on the heat transfer was relatively small and it can be neglected when the temperature of the heated aluminum disk is less than 400C.