Evaluation of the Radiation Effects of Residents Living Around the NSRI Under the External Hazards

The NSRR (Nuclear Safety Research Reactor) is a research reactor of TRIGA-ACPR (Annular Core Pulse Reactor) type, located in the Nuclear Science Research Institute (NSRI). The NSRR facility has been utilized for fuel irradiation experiments to study the behaviors of nuclear fuels under reactivity initiated accident (RIA) conditions. Under the new regulation standards after the Fukushima Daiichi accident, the research reactors are being regulated according to the risk of the facility. Graded approach is introduced in the regulation. In order to apply the graded approach, the radiation effects of residents living around the NSRI under the external hazards were evaluated and the level of the risk of the NSRR facility was investigating. This report is summarized for the result of the evaluation in case the safety functions were lost by the tornado, earthquake and following tsunami. As the result, the risk is confirmed to be low, since the effective dose of the residents has been below 5 mSv per event due to the loss of the safety functions by the tornado, earthquake and following tsunami.

Study of the linearity of CABRI experimental ionization chambers during RIA transients

CABRI is an experimental pulse reactor operated by CEA at the Cadarache research center and funded by the French Nuclear Safety and Radioprotection Institute (IRSN). For the purpose of the CABRI International Program (CIP), operated and managed by IRSN under an OECD/NEA framework it has been refurbished since 2003 to be able to provide experiments in prototypical PWR conditions (155 bar, 300 °C) in order to study the fuel behavior under Reactivity Initiated Accident (RIA) conditions. This paper first reminds the objectives of the power commissioning tests performed on the CABRI facility. The design and location of the neutron detectors monitoring the core power are also presented. Then it focuses on the different methodologies used to calibrate the detectors and check the consistency and co-linearity of the measurements. Finally, it presents the methods used to check the linearity of the neutron detectors up to the high power levels (~20 GW) reached during power transients. Some results obtained during the power tests campaign are also presented.

Stability Analysis of the IBR-2M Pulsed Reactor in Automatic Regulated Regime at Various Levels of Average Power

The IBR-2M pulse reactor is characterized by a high level of reactivity fluctuations and consequently by a high level of fluctuations in the regulated parameter as well as in the amplitude of the power pulses. Fluctuations of the regulated parameter relative to the average level in the standard stabilization regime usually fall within the range of 20% with certain peaks up to 40%, which is close to the limits of the emergency protection operation (50%). Under these conditions the automatic regulator may receive contradictory requirements. In this paper, the results of stability analysis of the IBR-2M reactor in the automatic regulating regime at various levels of average power are presented. It is shown that stability margins of the amplitude and the phase are enough, especially for the IBR-2M reactor operation with automatic regulator.

Preparation of Au Supported ZSM-5 Catalysts and its Special Performance in the Catalytic Cracking of Butane Reaction

Au/ZSM-5 was prepared by improved desorption-precipitation (DP) method using urea as precipitant. Au-samples were characterized by TEM, UV-Vis, XRD, pyridine-FTIR, FTIR and the other techniques. The catalytic performance of Au/ZSM-5 catalysts was carried out on the catalytic cracking of butane by mini-scale pulse reactor. Results showed that: 2.0wt% loading Au/ZSM-5 catalyst obtained the best activity that the n-butane conversion rate comes to 58% by weight,60% olefin selectivity and 10% aromatics selectivity; the i-butane conversion rate comes to 53%, 35% olefin selectivity and 15% aromatics selectivity.