scholarly journals Neutron flux distribution calculation for various spatial mesh of finite slab geometry using one-dimensional diffusion equation

2019 ◽  
Author(s):  
Mohammad Ali Shafii ◽  
Winka Wino Yunanda ◽  
Dian Fitriyani ◽  
Syeilendra Pramuditya
Keyword(s):  
Diffusion Equation ◽  
Neutron Flux ◽  
Flux Distribution ◽  
Slab Geometry ◽  
One Dimensional ◽  
Dimensional Diffusion ◽  
Neutron Flux Distribution ◽  
Distribution Calculation ◽  
Finite Slab

Improvement of Radioactivity Inventory Evaluation Procedure in Preparatory Tasks for Decommissioning

2010 ◽  
Author(s):  
Ken-ichi Tanaka ◽  
Hideaki Ichige ◽  
Hidenori Tanabe
Keyword(s):  
Power Plant ◽  
Neutron Flux ◽  
Nuclear Power ◽  
Flux Distribution ◽  
Neutron Transport ◽  
Reliable Information ◽  
Evaluation Procedure ◽  
Neutron Flux Distribution ◽  
Distribution Calculation ◽  
Radioactivity Distribution

Preparatory tasks for decommissioning of nuclear power plant start with radiological characterization. Residual radioactivity inventory evaluation is a main part of the characterization. Reliable information on the inventory is important for specification for decommissioning plan. Japan Atomic Power Company (JAPC) has already started these tasks for Tsuruga Nuclear Power Plant Unit 1 (TS-1). We can optimize decommissioning plan using the information. To obtain the reliable information, we improved an evaluation procedure. The procedure is divided into two main steps. First step is neutron flux distribution calculation and second one is radioactivity distribution calculation. Radioactivity distribution is calculated using neutron flux distribution. In this work, we improved the evaluation procedure to obtain the reliable information on the inventory. Because of the limitation of computer resource, two-dimension (2D) approximation model was applied to radioactivity distribution around Reactor Pressure Vessel (RPV). We can calculate reliable 2D neutron flux distribution by having better understanding of neutron transport phenomena. Neutron flux was measured at 30 locations in TS-1 Primary Containment Vessel (PCV) using activation foils. And in order to understand the neutron transport phenomenon inside the PCV, we also calculated neutron flux distribution with the three-dimensional (3D) discrete ordinates method calculation (Sn) code. By consideration about the result of the measurement and 3D calculation, we could understand the characteristics of the neutron flux distribution inside the PCV. To simulate the neutron flux distribution well with 2D Sn code, neutron flux behaviors inside the PCV had been investigated with referencing the measurement values and with observing calculated 3D neutron flux distribution. 2D calculation model had been modified repeatedly until reliable calculation result was provided. After several model modifications, the reliable 2D calculation was accomplished and important neutron transport phenomena that are necessary to simulate the neutron flux distribution well was understood. Network-parallel-computing technique was applied to radioactivity distribution calculation. Using this technique, we could calculate radioactivity at all space mesh points that were used with 2D Sn code and we obtained the radioactivity distribution. By using this distribution, we can estimate a quantity of radioactivity around RPV more accurately and optimize dismantling designs.

Rechner-Regelung der Neutronenflußverteilung in einem Leistungsreaktor / Computer control of the neutron flux distribution in a power reactor

1974 ◽  
Vol 22 (12) ◽  
Author(s):  
R. Grumbach
Keyword(s):  
Neutron Flux ◽  
Flux Distribution ◽  
Power Reactor ◽  
Computer Control ◽  
Neutron Flux Distribution

Die Neutronenflußverteilung in einem großen Kernreaktor unterliegt Störeinflüssen, deren Auswirkungen durch Regelung beherrscht werden müssen. Zu diesem Zweck wurde ein mit Hilfe eines Prozeßrechners anwendbares Verfahren entwickelt, das ein Regelungsgesetz aus einem Modell des vorhandenen Prozeßzustands errechnet; um zeitraubende physikalische Rechnungen zu vermeiden, werden die benötigten Modellparameter fortlaufend durch empirische Prozeßerkennung ermittelt. In Experimenten mit einem Leistungsreaktor wurde die Anwendbarkeit des Regelungsverfahrens bewiesen.

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