Current status of accident tolerant fuel (ATF) development, 1; Overview of ATF development conducted under the technology development project for improving nuclear safety

Yamashita, Shinichiro

Nihon Genshiryoku Gakkai-Shi ATOMO, 65(4), p.233 - 237, 2023/04

https://doi.org/10.3327/jaesjb.65.4_233

In the wake of the accident at the Fukushima Daiichi Nuclear Power Plant (NPP) of TEPCO due to the Great East Japan Earthquake in 2011, interest in the early implementation of accident tolerant fuel (ATF) not only for many existing NPPs but also for future NPPs, which is expected to dramatically improve the safety of light water reactors, has increased globally, and research and development is currently underway in many countries around the world. In this article, an overview of domestic ATF technology development that has been carried out with the support of the Ministry of Economy, Trade and Industry since 2015, will be introduced.

Study on cathodic reaction control efficiency by low alloy steels

Akashi, Masatsune*; Fukaya, Yuichi*; Asano, Hidekazu*

JNC TJ8400 2000-015, 46 Pages, 2000/02

JNC-TJ8400-2000-015.pdf:2.96MB

Difference of hydrogen generation phenomena on the surface of the Steels were not observed between carbon steel, atmospheric corrosion resisting steel and 5%-Ni steel. Rust layer was formed on these three-type of steels by steam oxidation method. And the chemical composition of the rust for the steels were basically two (2) layers structure for the previous two steels as hematite (FeO) based for the outer layer and magnetite (FeO) based for the inner layer. And for the last steel, it had three (3) layer in the rust as hematite (FeO) based for the outer layer, magnetite (FeO) based for the intermediate layer and Ni based layer for the inner layer. These steels showed mostly same Tafel gradient in their cathodic polarization curves compare with that for no rust specimens. However, the exchange current density which reaction is assumed as a hydrogen generation reaction was largely increased. The cathodic reaction for each steels whose surface is covered by magnetite layer might be accelerated, then the corrosion rate was considered as accelerated, too.

Irradiation-induced property changes of thermally oxidized nuclear graphites

; ;

Journal of Nuclear Materials, 152, p.283 - 288, 1988/00

https://doi.org/10.1016/0022-3115(88)90338-8

no abstracts in English

Influence of internal pressure on oxidation behavior of zrycaloy-2 cladding tube

Ioka, Ikuo; Terakado, Hiroshi*; Ebata, Koei*; Ogawa, Hiroaki; Osaka, Masahiko

no journal, , 

When the function of cooling system for a spent fuel pool loses, the spent fuel pins are covered with steam-air mixture environment. The spent fuel with internal pressure pin is oxidized during the process of dry out of the spent fuel pool. It is a possibility that the internal pressure which causes the crack formation of the oxide film accelerates the oxidation of Zircaloy-2 tube. The influence of internal pressure on oxidation behavior of Zircaloy-2 cladding tube was investigated. The oxidation test of the fuel pin with internal pressure was carried out at 600C in the saturated steam. The internal pressure was applied to Zircaloy-2 specimen up to 1.1 MPa. The thickness of ZrO decreased with increasing the internal pressure. One possible cause for the present result may be attributed to the suppression of phase transformation (monoclinic ZrO to tetragonal ZrO) which is considered to cause the degradation of oxide film by the internal pressure.