Design of a boiling water reactor equilibrium core using thorium-uranium fuel
In this paper the design of a Boiling Water Reactor (BWR) equilibrium core using thorium is presented; a heterogeneous blanket-seed core arrangement concept was adopted. The design was developed in three steps: in the first step two different assemblies were designed based on the integrated blanket-seed concept, they are the blanket-dummy assembly and the blanket-seed assembly. The integrated blanketseed concept comes from the fact that the blanket and the seed rods are located in the same assembly, and are burned-out in a once-through cycle. In the second step, a core design was developed to achieve an equilibrium cycle of 365 effective full power days in a standard BWR with a reload of 104 fuel assemblies designed with an average 235U enrichment of 7.5 w/o in the seed sub-lattice. The main operating parameters, like power, linear heat generation rate and void distributions were obtained as well as the shutdown margin. It was observed that the analyzed parameters behave like those obtained in a standard BWR. The shutdown margin design criterion was fulfilled by addition of a burnable poison region in the assembly. In the third step an in-house code was developed to evaluate the thorium equilibrium core under transient conditions. A stability analysis was also performed. Regarding the stability analysis, five operational states were analyzed; four of them define the traditional instability region corner of the power-flow map and the fifth one is the operational state for the full power condition. The frequency and the boiling length were calculated for each operational state. The frequency of the analyzed operational states was similar to that reported for BWRs; these are close to the unstable region that occurs due to the density wave oscillation phenomena in some nuclear power plants. Four transient analyses were also performed: manual SCRAM, recirculation pumps trip, main steam isolation valves closure and loss of feed water. The results of these transients are similar to those obtained with the traditional UO2 nuclear fuel.
- Research Organization:
- Universidad Nacional Autonoma de Mexico Facultad de Ingenieria. Paseo Cuauhnahuac 8532, 62550, Jiutepec, Mor. Mexico (MX); Comision Nacional de Seguridad Nuclear y Salvaguardias. Dr. Barragin 779 Col. Narvarte, 03020, Mexico, D. F. Mexico; Universidad Autonoma Metropolitana, Division de Ciencias Basicas e Ingenieria, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico, D.F. Mexico (MX)
- Sponsoring Organization:
- none (US)
- OSTI ID:
- 841148
- Resource Relation:
- Conference: Americas Nuclear Energy Symposium (ANES 2004), Miami, FL (US), 10/03/2004--10/06/2004; Other Information: PBD: 6 Oct 2004
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
29 ENERGY PLANNING
POLICY AND ECONOMY
BOILING
BURNABLE POISONS
DESIGN
FUEL ASSEMBLIES
NUCLEAR ENERGY
NUCLEAR FUELS
NUCLEAR POWER PLANTS
OSCILLATIONS
THORIUM
TRANSIENTS
WATER
BOILING WATER REACTOR
BWR
FUEL CYCLE