Study of boron dilution phenomenon in the core and fuel assemblies of Bushehr VVER-1000 reactor in normal operating conditions

• Autorzy: Rahmani Y. , Zarifi E. , Pazirandeh A.
• Języki publikacji: EN

Abstrakty

EN

The spatial temperature distributions in fuel and coolant, results in appearing local changes in those elements densities in the reactor core, and also due to the complete solubility of boric acid in the coolant, there will be a direct correlation between the changes in the boron concentration and the coolant density. Because of the gradual reduction of boron concentration, first a local positive reactivity will be inserted into the core which will cause slight thermo-neutronic fluctuations in the reactor core. Of course, the trend of this process in the case of excessive reduction of the density of the coolant and evaporation of water (accident scenarios) will be reversed and subsequently the negative reactivity will be given to the system. With regard to the importance of this phenomenon, the spatial changes of boron concentration in the core and fuel assemblies of Bushehr VVER-1000 reactor have been examined. In line with this, by designing a complete thermo-neutronic cycle and by using CITATION, WIMS D-5 and COBRAN-EN codes, coolant temperature distribution and boron concentration will be calculated through this procedure, which first by using the output results of WIMS and CITATION codes, the thermal power of each fuel assembly will be calculated and finally, by linking these data to COBRA-EN code and using core and sub-channel analysis methods, the three-dimensional (3D) calculations of boron dilution will be obtained in the core as well as the fuel assemblies of the reactor.

Słowa kluczowe

EN

VVER-1000; boron dilution; WIMS D5; CITATION; COBRA-EN; core and sub-channel analysis

• Wydawca: Institute of Nuclear Chemistry and Technology
• Czasopismo: Nukleonika
• Rocznik: 2010
• Tom: Vol. 55, No. 3
• Strony: 323--330
• Opis fizyczny: BIbliogr. 6 poz., rys.

Twórcy

autor

Rahmani Y.

autor

Zarifi E.

autor

Pazirandeh A.

• Faculty of Engineering, Department of Physics, Sari Branch, Islamic Azad University, Sari, Iran, Tel.: [phone], Fax: [phone],

Bibliografia

• 1. Basile D, Beghi M, Chierici R, Salina E, Brega E (1999) COBRA-EN, an updated version of the COBRA-3C/MIT code for thermal-hydraulic transient analysis of light water reactor fuel assemblies and cores. Report no. 1010/1, Italy
• 2. BUSHEHR VVER-1000 reactor (2003) Final Safety Analysis Report (FSAR), Chapter 4. Ministry of Russian Federation of Atomic Energy (Atomenergoproekt),Moscow
• 3. ORNL (1969) CITATION Code Manual. ORNL-TM-2496. Oak Ridge National Laboratory, Oak Ridge, Tennessee
• 4. Rahgoshay M, Rahmani Y (2007) Study of temperature distribution of fuel, clad and coolant in the VVER-1000 reactor core during group-10 control rod scram by using diffusion and point kinetic methods. Nukleonika 52;4:159–165
• 5. Vincenti E, Clusaz A (1971) COSTANZA-R,Z Code. Joint Nuclear Research Center, Ispra Establishment, Italy
• 6. WIMS D-5 manual, Winfrith Improved Multigroup Scheme Code System, NEA-1507 (1997) Atomic Energy Establishment, Winfrith, Dorchester