The Analysis for Ex-Vessel debris coolability of BWR

Matsumoto, Toshinori; Iwasawa, Yuzuru; Ajima, Kohei*; Sugiyama, Tomoyuki

Proceedings of Asian Symposium on Risk Assessment and Management 2020 (ASRAM 2020) (Internet), 10 Pages, 2020/11

The probability of ex-vessel debris coolability under the wet cavity strategy is analyzed. The first step is the uncertainty analyses by severe accident analysis code MELCOR to obtain the melt condition. Five uncertain parameters which are relating with the core degradation and transfer process were chosen. Input parameter sets were generated by LHS. The analyses were conducted and the conditions of the melt were obtained. The second step is the analyses for the behavior of melt under the water by JASMINE code. The probabilistic distribution of parameters are determined from the results of MELCOR analyses. Fifty-nine parameter sets were generated by LHS. The depth of water pool is set to be 0.5, 1.0 and 2.0 m. Debris height were compared with the criterion to judge the debris coolability. As the result, the success probability of debris cooling was obtained through the sequence of calculations. The technical difficulties of this evaluation method are also discussed.

Manufacturing technology and material properties of high nitrogen austenitic stainless steel forgings for ITER TF coil cases

Oshikawa, Takumi*; Funakoshi, Yoshihiko*; Imaoka, Hiroshi*; Yoshikawa, Kohei*; Maari, Yasutaka*; Iguchi, Masahide; Sakurai, Takeru; Nakahira, Masataka; Koizumi, Norikiyo; Nakajima, Hideo

Proceedings of 19th International Forgemasters Meeting (IFM 2014), p.254 - 259, 2014/09

ITER is a large-scale experiment that aims to demonstrate that it is possible to produce commercial energy from fusion. ITER Toroidal Field Coil Case (hereinafter referred to as "ITER TFCC") is one of the important components of ITER. The ITER TFCC materials are made of high nitrogen austenitic stainless steel and having various configurations. The ITER TFCC material which manufactured by JCFC has a complex configuration with heaver thickness than other materials. It is difficult to form near net shape to delivery configuration by ordinary open die forging method such as upset and stretching, because the ITER TFCC materials manufactured by JCFC have a complex configuration. Therefore ingot weight and lead time of machining increase when ITER TFCC materials are forged by ordinary open die forging method. Moreover, in order to get good attenuation at Ultrasonic examination, it is necessarily to make fine and uniform grain of the material. However, it is impossible to control grain size of austenitic stainless steel by heat treatment. The grain becomes fine and uniform by only forging process with suitable condition. Therefore, JCFC has studied suitable forging method to become near net shape to delivery configuration and also to get fine grain of center of the material. Based on these result, ITER TFCC materials were manufactured. This innovative forging process led to reduce the weight of ingot compared with general forging. And it had good Ultrasonic attenuation. It was confirmed that the results of material test and nondestructive examination satisfied the requirements of Japan domestic agency (hereinafter referred to as "JADA"). Moreover, the test coupons were taken from center of thick part of product and used for various tests. As the result of tests, it was confirmed that results of material test satisfied the requirements of JADA. It is clear that this innovative forging method is very suitable process for manufacturing of ITER TFCC materials.

Full-scale 3D vibration simulator for an entire nuclear power plant on the simple orchestration application framework

Kim, G.; Nakajima, Kohei*; Teshima, Naoya*; Tatekawa, Takayuki; Suzuki, Yoshio; Takemiya, Hiroshi

Progress in Nuclear Science and Technology (Internet), 2, p.634 - 638, 2011/10

https://doi.org/10.15669/pnst.2.634

We developed grid-enabled application of full-scale 3D vibration simulator for an entire nuclear power plant on simple orchestration application framework (SOAF). The simulator is an analysis system to study seismic response of a whole digitalized nuclear power plant. In the simulator, components of a power plant are treated in hierarchical manner so that large components are grouped at primary level and small components such as pipes at secondary level. Boundary condition data are transferred from the primary level to the secondary level. SOAF provides functionality to enable users to simply define the data transfer in pipelined scenario which is technically difficult to realize using the existing grid technology. In this paper, we discuss technical issues of the realization of pipelined scenario on grid and demonstrate effectiveness of SOAF by analysis of High Temperature Engineering Test Reactor of JAEA using grid-enabled application implementing SOAF.

Development of simple orchestration application framework and its application to burning plasma simulation

Tatekawa, Takayuki; Nakajima, Kohei*; Kim, G.; Teshima, Naoya; Suzuki, Yoshio; Takemiya, Hiroshi

High Performance Computing on Vector Systems 2010, p.107 - 120, 2010/09

In the atomic field, by integrating various simulation codes which were installed on distributed computers, large-scale and detailed simulations which aim explication of complicated phenomena. However integration of each simulation codes and cooperative operation of the integrated codes make heavy burden for researchers. We have developed the Simple Orchestration Application Framework (SOAF) to cooperatively control simulation codes on remote computers from a client PC. SOAF enables researchers to cooperatively execute various codes on grid infrastructure by only describing a configuration file including the information of execution codes and file flows among them. SOAF does not need substantial modification of the simulation codes. By using SOAF, we successfully execute four plasma simulation codes included in the "Burning Plasma Integrated Code" according to the scenario described in the configuration file.

Simple orchestration application framework to control integrated simulations on grid

Tatekawa, Takayuki; Nakajima, Kohei*; Kim, G.; Kino, Chiaki; Teshima, Naoya; Suzuki, Yoshio; Takemiya, Hiroshi

FUJITSU Famirikai Rombunshu (Internet), 19 Pages, 2010/03

We have introduced about the framework to make the integration of large and complicated simulation such as a proof strength simulation of nuclear power plants and a control simulation of nuclear fusion plasma which codes are installed to distributed computers. We able to carry out detailed simulations by integrating various simulation methods with development of simulation technique. However it becomes a burden to control the integration of each simulation code for researchers. We have noticed that the execution scenarios of each code in cooperated simulation are roughly categorized to workflow type, pipeline type, and conditional branch type. Then we have developed the framework in which just write those patterns in a configuration file and achieve the cooperative execution of element codes without substantial modification of simulation codes.

Grid use not to consider grid; Proposal of seamless API and adaptation to applications

Nakajima, Kohei; Suzuki, Yoshio; Teshima, Naoya; Sugimoto, Shinichiro*; Yoshimura, Shinobu*; Nakajima, Norihiro

Zen NEC C&C Shisutemu Yuza Kai Heisei-20-Nendo Rombunshu (CD-ROM), 13 Pages, 2009/02

Grid computing environment is equipped with a lot of tools to manage jobs and computers. Thereby, user can use the computers without directly access. However, user has to acquire usage of these tools even when user does an easy job because all usages of these tools are peculiar to the grid base. A lot of users think that the grid is difficult even though these tools exist. Then, we developed script generator API to make the job script. These settings were made easy by this API in the user application. In this paper, the outline of this API and the adjustment to the application are described.

Development of three-dimensional virtual plant vibration simulator on grid computing environment ITBL-IS/AEGIS

Suzuki, Yoshio; Nishida, Akemi; Araya, Fumimasa; Kushida, Noriyuki; Akutsu, Taku; Teshima, Naoya; Nakajima, Kohei; Kondo, Makoto; Hayashi, Sachiko; Aoyagi, Tetsuo; et al.

Journal of Power and Energy Systems (Internet), 3(1), p.60 - 71, 2009/00

https://doi.org/10.1299/jpes.3.60

Center for computational science and e-systems of Japan Atomic Energy Agency is carrying out R&D in the area of extra large-scale simulation technologies for solving nuclear plant structures in its entirety. Specifically, we focus on establishing a virtual plant vibration simulator on inter-connected supercomputers intended for seismic response analysis of a whole nuclear plant. The simulation of a whole plant is a very difficult task because an extremely large dataset must be processed. To overcome this difficulty, we have proposed and implemented a necessary simulation framework and computing platform. The computing platform enables an extra large-scale whole nuclear plant simulation to be carried out on a grid computing platform ITBL-IS and AEGIS. The simulation framework based on the computing platform has been applied to a linear elastic analysis of the reactor pressure vessel and cooling systems of the nuclear research facility, HTTR.

Development of three-dimensional virtual plant vibration simulator on grid computing environment ITBL-IS/AEGIS

Suzuki, Yoshio; Nakajima, Norihiro; Araya, Fumimasa; Hazama, Osamu; Nishida, Akemi; Kushida, Noriyuki; Akutsu, Taku; Teshima, Naoya; Nakajima, Kohei; Kondo, Makoto; et al.

Proceedings of 16th International Conference on Nuclear Engineering (ICONE-16) (CD-ROM), 9 Pages, 2008/05

Intense femto-second laser-driven X-ray source coupled with multiple directional quantum beams for applications

Daido, Hiroyuki; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Yogo, Akifumi; Mori, Michiaki; Li, Z.*; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.

X-Ray Lasers 2006; Springer Proceedings in Physics, Vol.115, p.595 - 605, 2007/00

At present, using ultra-short high intensity lasers at APRC, JAEA Kansai photon research institute, we are developing laser driven multiple quantum beams such as protons, X-rays, electrons and THz waves. These beams are perfectly synchronized with each other. The pulse duration of each beam is lass than a pico-second. They have sharp directionality with high brightness. If we properly combined these, we have new pump-probe techniques for various applications.

Example of answers to the problems of the 36th examination for the chief engineer of nuclear fuel, 2004

Yachi, Shigeyasu; Nakamura, Jinichi; Amaya, Masaki; Nakajima, Kunihisa; Komuro, Yuichi; Nakajima, Katsuaki*; Kobayashi, Yasuhiko; Sato, Tadashi*; Suga, Shinichi*; Noguchi, Hiroshi; et al.

JAERI-Review 2004-020, 61 Pages, 2004/09

JAERI-Review-2004-020.pdf:1.85MB

This report provides an example of answers to the problems of the 36th Examination for the Chief Engineer of Nuclear Fuel. This examination was done as a national qualification in March 2004. Brief explanations or references are added to some answers.