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.

Improvement of the NSRR simulator

Murao, Hiroyuki; Yachi, Shigeyasu; Ota, Kazunori; Muramatsu, Yasuyuki; Nakamura, Takehiko; Terakado, Yoshibumi

JAERI-Tech 2003-094, 41 Pages, 2004/01

JAERI-Tech-2003-094.pdf:2.26MB

Prior to actual runs in the shaped pulse and in the combined pulse operations, the online simulation and the offline simulation must be performed to examine safety and appropriation. Actual reactor power of the NSRR can be simulated practically, but a slight difference canbe observed between the present simulation results and the actual operation during the NSRR start-up phase and power controled operation. Regulating rod worth and fuel temperature feedback reactivity were re-evaluated and installed into the simulators. As a result, the accuracy of the simulator was remarkably improved. So that the application and safety of the shaped pulse and combined pulse operation were improved.

High power transient characteristics and capability of NSRR

Nakamura, Takehiko; Katanishi, Shoji; Kashima, Yoichi; Yachi, Shigeyasu; Yoshinaga, Makio; Terakado, Yoshibumi

Journal of Nuclear Science and Technology, 39(3), p.264 - 272, 2002/03

https://doi.org/10.3327/jnst.39.264

In order to study fuel behavior under abnormal transients and accidents, the control system of the Nuclear Safety Research Reactor (NSRR) of the Japan Atomic Energy Research Institute (JAERI) was modified to achieve high power transients. With this new operational mode, called Shaped Pulse (SP), transients at the maximum power of 10 MW can be conducted for a few seconds. This new operational mode supplements the previous Natural Pulse (NP) operation at the maximum power of 23 GW for milliseconds. For high power transient operation, a simulator using a point kinetic model was developed, and characteristics of the NSRR in the new operational mode were examined through tests and calculations. With the new operational mode, new types of fuel irradiation tests simulating power oscillations of boiling water reactors (BWRs) can to be conducted in the NSRR. Reactor characteristics and capability, such as control rod worth, feedback reactivity, and operational limits of the NSRR for SP operations are discussed.