scholarly journals Analysis of fuel subassembly innerduct configurational effects on the core characteristics and power distribution of a sodium-cooled fast breeder reactor

2015 ◽  
Vol 53 (8) ◽  
pp. 1155-1163 ◽  
Author(s):  
Kazuya Ohgama ◽  
Yoshihiro Nakano ◽  
Shigeo Ohki
Keyword(s):  
Power Distribution ◽  
Fast Breeder Reactor ◽  
The Core ◽  
Core Characteristics

scholarly journals Improvement of Core Performance by Introduction of Moderators in a Blanket Region of Fast Reactors

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Toshio Wakabayashi
Keyword(s):  
Power Distribution ◽  
Outer Core ◽  
Monte Carlo Code ◽  
The Core ◽  
Fuel Burn ◽  
Fuel Assemblies ◽  
Core Characteristics ◽  
Power Flattening ◽  
Reactivity Insertion ◽  
Operational Time

An application of deuteride moderator for fast reactor cores is proposed for power flattening that can mitigate thermal spikes and alleviate the decrease in breeding ratio, which sometimes occurs when hydrogen moderator is applied as a moderator. Zirconium deuteride is employed in a form of pin arrays at the inner most rows of radial blanket fuel assemblies, which works as a reflector in order to flatten the radial power distribution in the outer core region of MONJU. The power flattening can be utilized to increase core average burn-up by increasing operational time. The core characteristics have been evaluated with a continuous-energy model Monte Carlo code MVP and the JENDL-3.3 cross-section library. The result indicates that the discharged fuel burn-up can be increased by about 7% relative to that of no moderator in the blanket region due to the power flattening when the number of deuteride moderator pins is 61. The core characteristics and core safety such as void reactivity, Doppler coefficient, and reactivity insertion that occurred at dissolution of deuteron were evaluated. It was clear that the serious drawback did not appear from the viewpoints of the core characteristics and core safety.

Alternative Absorber Materials for Control Rods in ALFRED

2021 ◽  
Author(s):  
Hui Guo ◽  
Xin Jin ◽  
Kuaiyuan Feng ◽  
Hanyang Gu
Keyword(s):  
Fast Reactor ◽  
Power Distribution ◽  
Operating Life ◽  
Insertion Depth ◽  
Control Rod ◽  
The Core ◽  
Sodium Fast Reactor ◽  
Reference Design ◽  
Core Characteristics ◽  
Control Rods

Abstract The next-generation reactors require improved safety performance and longer cycle length, which initiate the research on alternative absorber materials. In this context, potential absorber materials including borides (B4C, HfB2, and ZrB2), rare earth oxides (Eu2O3, Gd2O3, Sm2O3, and Dy2TiO5), metals/alloys (Hf and AIC), and metal hydride (HfHx) were compared in a large sodium fast reactor. The design of control rods for Generation-IV fast reactors strongly depends on the core characteristics. In this paper, some alternative absorbers are assessed in a lead fast reactor ALFRED using depletion capability in the Monte-Carlo particle transport code OpenMC. Results show that the ALFRED reference control rod design with B4C largely satisfies the shutdown and operation requirements. 60% 10B enriched HfB2 and HfH1.18 can replace the operation part of the reference design. In the future, the safe operating life of B4C and HfB2 should be assessed taking into account the irradiation-induced swelling, temperature margin, and gas release. HfH1.18 has a limited and local influence on the core power distribution. Eu2O3 has little loss on the absorption ability after 5 cycle irradiation. This oxide absorber satisfies the shutdown function even with only half control rod insertion, while its critical insertion depth at beginning of the cycle should be increased to realize reactivity compensation function.

scholarly journals The core characteristics and nursing care activities in psychiatric intensive care units in Sweden

2008 ◽  
Vol 17 (2) ◽  
pp. 98-107 ◽  
Author(s):  
Martin Salzmann-Erikson ◽  
Kim Lützén ◽  
Ann-Britt Ivarsson ◽  
Henrik Eriksson
Keyword(s):  
Intensive Care ◽  
Intensive Care Units ◽  
Nursing Care ◽  
The Core ◽  
Core Characteristics

Nuclear Instrumentation Systems in Prototype Fast Breeder Reactor

2004 ◽  
Author(s):  
P. M. Vijayakumaran ◽  
C. P. Nagaraj ◽  
C. Paramasivan Pillai ◽  
R. Ramakrishnan ◽  
M. Sivaramakrishna
Keyword(s):  
Neutron Flux ◽  
Early Warning System ◽  
Warning System ◽  
Radiation Monitoring ◽  
Fast Breeder Reactor ◽  
Delayed Neutrons ◽  
The Core ◽  
Flux Monitoring ◽  
Nuclear Instrumentation ◽  
Fission Chambers

The nuclear instrumentation systems of the Prototype Fast Breeder Reactor (PFBR) primarily comprise of global Neutron Flux Monitoring, Failed Fuel Detection & Location, Radiation Monitoring and Post-Accident Monitoring. High temperature fission chambers are provided at in-vessel locations for monitoring neutron flux. Failed fuel detection and location is by monitoring the cover gas for fission gases and primary sodium for delayed neutrons. Signals of the core monitoring detectors are used to initiate SCRAM to protect the reactor from various postulated initiating events. Radiation levels in all potentially radioactive areas are monitored to act as an early warning system to keep the release of radioactivity to the environment and exposure to personnel well below the permissible limits. Fission Chambers and Gamma Ionisation Chambers are located in the reactor vault concrete for monitoring the neutron flux and gamma radiation levels during and after an accident.

CFD Investigation of Thermal-Hydraulic Behaviors in Full Reactor Core for Sodium-Cooled Fast Reactor

2018 ◽  
Author(s):  
Jing Chen ◽  
Dalin Zhang ◽  
Suizheng Qiu ◽  
Kui Zhang ◽  
Mingjun Wang ◽  
...  
Keyword(s):  
Fast Reactor ◽  
Power Distribution ◽  
Three Dimensional ◽  
Reactor Core ◽  
Heat Removal ◽  
The Core ◽  
Computational Fluid Dynamics Cfd ◽  
Heat Removal System ◽  
China Experimental Fast Reactor ◽  
Full Core

As the first developmental step of the sodium-cooled fast reactor (SFR) in China, the pool-type China Experimental Fast Reactor (CEFR) is equipped with the openings and inter-wrapper space in the core, which act as an important part of the decay heat removal system. The accurate prediction of coolant flow in the reactor core calls for complete three-dimensional calculations. In the present study, an investigation of thermal-hydraulic behaviors in a 180° full core model similar to that of CEFR was carried out using commercial Computational Fluid Dynamics (CFD) software. The actual geometries of the peripheral core baffle, fluid channels and narrow inter-wrapper gap were built up, and numerous subassemblies (SAs) were modeled as the porous medium with appropriate resistance and radial power distribution. First, the three-dimensional flow and temperature distributions in the full core under normal operating condition are obtained and quantitatively analyzed. And then the effect of inter-wrapper flow (IWF) on heat transfer performance is evaluated. In addition, the detailed flow path and direction in local inter-wrapper space including the internal and outlet regions are captured. This work can provide some valuable understanding of the core thermal-hydraulic phenomena for the research and design of SFRs.

scholarly journals Characterization of dissimilar aluminum-copper material joining by controlled dual laser beam

2021 ◽  
Author(s):  
Joon Ho Cha ◽  
Hae Woon Choi
Keyword(s):  
Laser Beam ◽  
Power Distribution ◽  
Near Infrared ◽  
Weld Zone ◽  
Tensile Tests ◽  
Bead Width ◽  
Single Beam ◽  
The Core ◽  
Beam Laser ◽  
Dual Laser

Abstract Laser technology has many advantages in welding for the manufacture of EV battery packs. Aluminum (Al) and copper (Cu) are welded using a dual laser beam, suggesting the optimum power distribution for the core and ring beams. Due to the very high reflectance of Cu and Al exposed to near-infrared lasers, the material absorbs a very small amount of energy. Compared to single beam laser welding, dual beam welding has significantly improved surface quality by controlling surface solidification. The study focused on the quality of weld surface beads, weld properties and tensile strength by varying the output ratio of the core beam to the ring beam. Optimal conditions of Al6061 were a 700 W core beam, a 500 W ring beam and 200 mm/s of weld speed. For the C1020P, the optimum conditions were a center beam of 2500 W, a ring beam of 3000 W and a welding speed of 200 mm/s. In laser lap welding of Al-Al and Al-Cu, the bead width and the interfacial bead width of the joint increased as the output increased. The penetration depth did not change significantly, but small pores were formed at the interface of the junction. Tensile tests were performed to demonstrate the reliability of the weld zone, and computer simulations provided analysis of the heat distribution for optimal heat input conditions.

scholarly journals Research on key influence factors of creativity development of applied undergraduates based on PCA

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiangmin Ren ◽  
Jingwei Yu
Keyword(s):  
Principal Component Analysis ◽  
Influence Factors ◽  
Principal Component ◽  
Heilongjiang Province ◽  
Key Factors ◽  
Factors Affecting ◽  
The Core ◽  
Creativity Development ◽  
Teachers And Students ◽  
Core Characteristics

Abstract Creativity is one of the core characteristics of talent; for this reason, the creativity development of applied undergraduates should be one of the basic components of their education. This article gives an overview of the meaning of the creativity of applied undergraduates and makes a literature knowledge-mining and expert investigation on the factors affecting the creativity development. We obtained more than 100 influencing factors, filtered out the duplicative factors, and formed the remaining factors into a questionnaire. A survey was conducted among 1460 teachers and students of some applied undergraduates in Heilongjiang Province. By using principal component analysis (PCA) to analyse the questionnaire, the key factors that affect the creativity development of applied undergraduates are obtained, and the key factors are systematically analysed. According to the results of the analysis, the specific ways and methods of the creativity development of applied undergraduates are put forward.

scholarly journals Validation of Doppler Temperature Coefficients and Component Power Distribution for the Advanced Neutronics Component Program KYLIN V2.0

2021 ◽  
Vol 9 ◽  
Author(s):  
Lei Jichong ◽  
Xie Jinsen ◽  
Chen Zhenping ◽  
Yu Tao ◽  
Yang Chao ◽  
...  
Keyword(s):  
Engineering Design ◽  
Power Distribution ◽  
Nuclear Power ◽  
Nuclear Engineering ◽  
Temperature Coefficients ◽  
The Core ◽  
Fuel Assemblies ◽  
Design Requirements ◽  
Design Software ◽  
Good Agreement

This work is interested in verifying and analyzing the advanced neutronics assembly program KYLIN V2.0. Assembly calculations are an integral part of the two-step calculation for core design, and their accuracy directly affects the results of the core physics calculations. In this paper, we use the Doppler coefficient numerical benchmark problem and CPR1000 AFA-3G fuel assemblies to verify and analyze the advanced neutronics assembly program KYLIN V2.0 developed by the Nuclear Power Institute of China. The analysis results show that the Doppler coefficients calculated by KYLIN V2.0 are in good agreement with the results of other well-known nuclear engineering design software in the world; the power distributions of AFA-3G fuel assemblies are in good agreement with the results of the RMC calculations, it’s error distribution is in accordance with the normal distribution. It shows that KYLIN V2.0 has high calculation accuracy and meets the engineering design requirements.

Sign in / Sign up

Export Citation Format

Share Document