Summary of Research Project Results under JSPS FY2002
"Research for the Future Program"

1.Research Institution The University of Tokyo
2.Research Area Physical and Engineering Sciences
3.Research Field Innovation in Energy Generation, Conversion, Materials and Systems for the Future
4.Term of Project FY 1998 - FY 2002
5.Project Number 98P00901
6.Title of Project Basic Research on the Development of New Materials Used under Strong Radiation Fields

7.Project Leader
Name Institution,Department Title of Position
Yosuke, Katsumura The University of Tokyo, Graduate School of Engineering Professor

8.Core Members

Name Institution,Department Title of Position
Haruki, Madarame The University of Tokyo, Graduate School of Engineering Professor
Naoto, Sekimura The University of Tokyo, Graduate School of Engineering Professor
Hiroyuki Takahashi The University of Tokyo, Research into Artifacts, Center for Engineering Associate Professor

9.Summary of Research Results

  In the present research project, basic technology for the realization of the supercritical water-cooled reactors has been developed.
  In order to establish the systematic approach to radiation damage in structural material, an in-situ measurement method combined with an ion accelerator and an AFM spectrometer has been developed. Based on microscopic mechanism, evaluation method of the lifetime and radiation resistance for the material under radiation field has been investigated and, as a result, a multi-scale modeling has been proposed.
  A visualization method for the heat transport close to the critical point in supercritical CO2 was established and it was found that a certain structure appears under higher heat flux. In addition, by using a frame struggling method, two dimensional velocity distribution of the fluid was derived. In parallel, two-dimensional simulation code was adapted to obtain a correlation equation for the heat transport under different heat flux in supercritical water.
  By pulse radiolysis method, many kinds of transient radicals in supercritical water has been observed and the existence of hydrated electron in supercritical water was confirmed for the first time. It was found that the absorption bands shift to red or blue with increasing temperature, which was depend on the kind of the radical. G-values of the water decomposition products were determined as a function of temperature up to 400°C and the values are strongly dependent of pressure, namely density in supercritical water.
  In order to develop a new detector having an extremely high energy resolution, a transition-edge micro-calorimeter operated at cryogenic temperature was employed and less than 10 eV energy resolution was obtained. This is one of the best detectors developed in the world so far. Dynamic change of the super-conducting state of the detector has been investigated by experiment and simulation, which helps to understand the mechanism of the detector. In parallel, an AFM was applied to observe the radiation damage induced by ion beam irradiation and it was revealed that this technique is useful and powerful.

10.Key Words
(1)supercritical water-cooled reactor   (2)multi-scale modeling   (3)in-situ observation
(4)visualization   (5)radiolysis   (6)pulse radiolysis
(7)transition-edge micro-calorimeter