http://hdl.handle.net/1721.1/67472 Fri, 24 May 2013 00:55:05 GMT 2013-05-24T00:55:05Z http://hdl.handle.net/1721.1/77615 Feasibility of Breeding in Hard Spectrum Boiling Water Reactors with Oxide and Nitride Fuels Feng, Bo; Kazimi, Mujid S.; Forget, Benoit This study assesses the neutronic, thermal-hydraulic, and fuel performance aspects of using nitride fuel in place of oxides in Pu-based high conversion light water reactor designs. Using the higher density nitride fuel hardens the neutron energy spectrum and results in higher breeding ratios. The state-of-the-art high conversion light water reactor, the Resource-renewable Boiling Water Reactor (RBWR), served as the template core upon which comparative studies between nitride and oxide fuels were performed. A 1/3 core reactor physics model was developed for the RBWR using the stochastic transport code MCNP. The code was coupled with a lumped channel thermal-hydraulics 5-channel model for steady-state analyses. The depletion code MCODE, which links MCNP with ORIGEN, was used for all burnup calculations. Select physics parameters were calculated and with the exception of the void coefficients, agreed with reported data. The void coefficients of the coupled core were calculated to be slightly positive using two different methods (10% power increase and 5% flow reduction). The standard RBWR assembly designs, which use tight lattice hexagonal fuel rod arrays, with oxide fuel were then replaced with various nitride fuel assembly designs to determine the potential increase in breeding ratio, the potential to breed with pressurized water, and the potential to improve the critical power ratio with a wider pin pitch. Without changing the assembly geometry or discharge burnup, using nitride fuel resulted in a breeding ratio of 1.14. Using single-phase liquid water, the nitride fuel RBWR assembly resulted in a conversion ratio of 1.00. Another nitride fuel assembly design with boiling water maintained a 1.04 breeding ratio while increasing the pitch-to-diameter ratio from 1.13 to 1.20. This modification increased the hot assembly critical power ratio from 1.22 to 1.36, as calculated using the Liu- 2007 correlation. A high-porosity nitride fuel is recommended for high burnup conditions, to accommodate the nitride fuel’s higher swelling and less favorable mechanical properties compared to the oxide fuel. The high porosity allows additional volume for pressure-induced densification, alleviating swelling and subsequent cladding strain. To predict the performance of high-porosity nitride fuel, fission gas and fuel behavior mechanistic models were developed for high burnup and low-temperature conditions. These models were validated with reported irradiation data and implemented, along with fuel material properties, into the steady-state fuel behavior code FRAPCON-EP. Under simulated RBWR conditions, a fuel density no more than 85% of theoretical density is recommended to maintain satisfactory fuel performance. Wed, 01 Jun 2011 00:00:00 GMT http://hdl.handle.net/1721.1/77615 2011-06-01T00:00:00Z http://hdl.handle.net/1721.1/77614 PROLIFERATION RESISTANT, LOW COST, THORIA-URANIA FUEL FOR LIGHT WATER REACTORS Kazimi, Mujid S.; Driscoll, Michael J.; Ballinger, Ronald G.; Clarno, K. T.; Czerwinski, Kenneth R.; Hejzlar, Pavel; LaFond, P. J.; Long, Y.; Meyer, J. E.; Reynard, M. P.; Schultz, S. P.; Zhao, X. 1. Summary Project Objectives: Our objective is to develop a fuel consisting of mixed thorium dioxide and uranium dioxide (ThO[subscript 2]-UO[subscript 2]) for existing light water reactors (LWRs) that (a) is less expensive overall than the current uranium-dioxide (UO[subscript 2]) fuel, (b) is very resistant to nuclear weapons-material proliferation, (c) results in a more stable and insoluble waste form, and, (d) generates less spent fuel per unit energy production. This project is being conducted in collaboration with INEEL. This annual report presents the MIT progress in the investigations from October 1998 up to June 1999. Tue, 01 Jun 1999 00:00:00 GMT http://hdl.handle.net/1721.1/77614 1999-06-01T00:00:00Z http://hdl.handle.net/1721.1/75738 High Performance Fuel Design for Next Generation PWRs: 11th Quarterly Report Kazimi, Mujid S.; Hejzlar, Pavel; Feng, Dandong; Kohse, Gordon E.; Morra, Paolo; Ostrovsky, Yakov; Saha, Pradip; Xu, Zhiwen; Yuan, Yi; Carpenter, David M.; Feinroth, Herbert; Lahoda, Edward J.; Sundaram, Ramu K.; Hamilton, Holly I. Technical Narrative: The overall objective of this NERI project is to examine the potential for a high performance advanced fuel for Pressurized Water Reactors (PWRs), which would accommodate a substantial increase of core power density while simultaneously providing larger thermal margins than current PWRs. This advanced fuel will have an annular geometry that allows internal and external coolant flow and heat removal. The project is led by the Massachusetts Institute of Technology (MIT), with collaboration of four industrial partners – Gamma Engineering Corporation, Westinghouse Electric Corporation, Framatome ANP (formerly Duke Engineering & Services), and Atomic Energy of Canada Limited. Quarterly Report for Project DE-FG03-01SF22329 April 2004 – June 2004 Thu, 01 Jul 2004 00:00:00 GMT http://hdl.handle.net/1721.1/75738 2004-07-01T00:00:00Z http://hdl.handle.net/1721.1/75737 Flexible Conversion Ratio Fast Reactor Systems Evaluation Final Report Todreas, Neil E.; Hejzlar, Pavel; Fong, Chris J.; Nikiforova, Anna; Petroski, Robert; Shwageraus, Eugene; Whitman, Joshua Executive Summary: The goal of this project is to develop the conceptual designs of fast flexible conversion ratio reactors using lead and liquid salt coolants and to compare the results with a gascooled fast reactor developed in an MIT NERI project and a sodium-cooled reactor under development at ANL. To maintain the scope of the study manageable within the 2-year time frame and funding constraints, core designs that fit in the same reactor plant were executed for two limiting conversion ratios: (1) near zero, to transmute legacy waste and (2) near unity, to operate in a sustainable closed cycle. To reap the benefits of economy of scale, a large power rating of 2400MWt was set as the target thermal power for both reactor designs. In addition, the achievement of inherent reactor shutdown in unprotected accidents (without scram) was set as a desirable goal. Project DE-FC07-06ID14733 Sun, 01 Jun 2008 00:00:00 GMT http://hdl.handle.net/1721.1/75737 2008-06-01T00:00:00Z