FUEL CYCLE PROGRAM, A BOILING WATER REACTOR RESEARCH DEVELOPMENT PROGRAM. First Summary Report for March 1959-July 1960

Thorium has a possibility as alternative nuclear reactor fuel. Thorium has several good neutronic properties so that could provide higher capacity factor, more stable and insoluble, very resistant to weapon-material proliferation, and more cost effective. On the other hand, regarding the previous study [, neutronic performance of Thorium utilization as nuclear fuelwithout burnable poison materials additionyielded high excess reactivity. In order to handle this safety consideration without increase control mechanically, there was possible to add burnable poison (BP) materials. BP materials could absorb faster from fuel burn up because they have high cross section capture. Besides, they could left poison residue as few as they can in the end of fuel cycle. Protactinium, Pa, was a nuclide which has the same characteristic such standard BP materials. This paper describes the effect of addition of Pa-231 towards excess reactivity and operation time. The optimized design resulted in boiling water reactor with active volume 5,193.034 liter, power 182 MWt, operation time 28 years and maximum excess reactivity 0,56% dk/k. These specifications were obtained using fuel percentage composition of U-232 as much as 10 13% and Pa-231 as much as 9.36 16.01%.

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Modular Boiling Water Reactor Concept

Volume 3: Nuclear Fuel and Material, Reactor Physics, and Transport Theory ◽

10.1115/icone26-81196 ◽

2018 ◽

Author(s):

Liao Yi ◽

Wang Cong ◽

Chen Lei

Keyword(s):

Fuel Cycle ◽

Natural Circulation ◽

Boiling Water ◽

Boiling Water Reactor ◽

Safety Feature ◽

Water Reactor ◽

Fuel Cycles ◽

Fuel Assemblies ◽

Safety Features ◽

Thermal Hydraulic Analysis

Modular boiling water reactor (MBWR) can be considered as a small sized economic simplified boiling water reactor (ESBWR). It has the advantage of easier fabrication, transportation and construction. In this paper, a 65MWe MBWR core was designed with natural circulation, passive safety features, high power density and an 18 months fuel cycle. The MBWR core consists of 104 fuel assemblies with 4.6 w/o U-235, the assemblies were divided into 3 batches based on the depletion level, the batches shuffled at the end of each cycle. The core converged to equilibrium after 8 fuel cycles. A steady-state equilibrium fuel cycle depletion analysis was performed over a 540 day cycle using the HELIOS and PARCS software. The control blades insertion patterns were chosen to minimize axial and radial power peaking and provide uniform burnup throughout the cycle. At the end of the equilibrium cycle, 16% of total control blade worth remained inserted and the average assembly burnup is 21.318 GWd/MTHM. Thermal hydraulic analysis was also performed to insure the core’s safety feature.

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