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A validation study of existing neutronics tools against ZPPR-21 and ZPPR-15 critical experiments.

Description: A study was performed to validate the existing tools for fast reactor neutronics analysis against previous critical experiments. The six benchmark problems for the ZPPR-21 critical experiments phases A through F specified in the Handbook of Evaluated Criticality Safety Benchmark Experiments were analyzed. Analysis was also performed for three loading configurations of the ZPPR-15 Phase A experiments. As-built core models were developed in XYZ geometries using the reactor loading records and drawer master information. Detailed Monte Carlo and deterministic transport calculations were performed, along with various modeling sensitivity analyses. The Monte Carlo simulations were carried out with the VIM code with continuous energy cross sections based on the ENDF/B-V.2 data. For deterministic calculations, region-dependent 230-group cross sections were generated using the ETOE-2/MC-2/SDX code system, again based on the ENDF/B-V.2 data. Plate heterogeneity effects were taken into account by SDX unit cell calculations. Core calculations were performed with the TWODANT discrete ordinate code for the ZPPR-21 benchmarks, and with the DIF3D nodal transport option for the ZPPR-15 experiments. For all six ZPPR-21 configurations where the Pu-239 concentration varies from 0 to 49 w/o and the U-235 concentration accordingly varies from 62 to 0 w/o, the core multiplication factor determined with a 230-group TWODANT calculation agreed with the VIM Monte Carlo solution within 0.20 %{Delta}k, and there was no indication of any systematic bias. The quality of principal cross sections generated with the MC-2 code was comparable to that of VIM cross sections. The overall reactivity effect due to the errors in the 230-group principal cross sections was estimated to be less than 0.05 %{Delta}k. The statistics of the differences between calculated values and specified benchmark experimental values showed similar bias (from -0.28 %{Delta}k to 0.33 %{Delta}k) for MC{sup 2}-2/TWODANT and VIM. This result suggests that the criticality prediction accuracy of MC{sup ...
Date: September 30, 2007
Creator: Yang, W.S. & Kim, S.J. (Nuclear Engineering Division)
Partner: UNT Libraries Government Documents Department

Economic assessment of proposed electric-discharge non-thermal plasma field-pilot demonstration units for NO{sub x} removal in jet-engine exhaust: White paper for SERDP Project CP-1038

Description: This project is currently evaluating non-thermal plasma (NTP) technologies for treating jet-engine exhaust arising from DoD test facilities. In the past, some economic analyses for NTP de-NO{sub x} have shown that it is not economical, compared to other techniques. The main reasons for this conclusion was that the previous analyses examined stand-alone, or less mature electrical-discharge reactors, or electron-beam based systems that incorporated both chemical additives and quite expensive electron accelerators. Also, in contrast to more recent developments, both the discharge and electron-beam techniques of the past did not extensively incorporate methods to increase the yields of active NO{sub x}-decomposing species. In an earlier White paper and a Project Report, the authors have analyzed the costs of more mature NTP systems incorporating chemical additives and new-concept NTP technologies for jet-engine emissions control and have shown lower exhaust-gas treatment costs for NTP systems compared to baseline standard de-NO{sub x} technologies like Selective Catalytic Reduction (SCR) combined with a wet scrubber or SCR combined with an electrostatic precipitator (ESP). In this paper, the authors will examine their most-promising candidate NTP reactor systems for a field-pilot demonstration on jet-engine exhaust and discuss the economic analyses for these hybrid units, which show that the economics of the proposed candidate systems are more favorable than earlier NTP reactor economic-assessment conclusions for NO{sub x} removal.
Date: January 5, 1999
Creator: Rosocha, L. A.; Chang, J. S.; Urashima, Kuniko; Kim, S. J. & Miziolek, A. W.
Partner: UNT Libraries Government Documents Department

Boiling Visualization and Critical Heat Flux Phenomena In Narrow Rectangular Gap

Description: An experimental study was performed to investifate the pool boling critical hear flux (CHF) on one-dimensional inclined rectangular channels with narrow gaps by changing the orientation of a copper test heater assembly. In a pool of saturated water at atmospheric pressure, the test parameters include the gap sizes of 1,2,5, and 10 mm, andthe surface orientation angles from the downward facing position (180 degrees) to the vertical position (90 degress) respectively.
Date: December 1, 2004
Creator: Kim, J. J.; Kim, Y. H.; Kim, S. J.; Noh, S. W.; Suh, K. Y.; Rempe, J. et al.
Partner: UNT Libraries Government Documents Department

Status report on the Small Secure Transportable Autonomous Reactor (SSTAR) /Lead-cooled Fast Reactor (LFR) and supporting research and development.

Description: This report provides an update on development of a pre-conceptual design for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) plant concept and supporting research and development activities. SSTAR is a small, 20 MWe (45 MWt), natural circulation, fast reactor plant for international deployment concept incorporating proliferation resistance for deployment in non-fuel cycle states and developing nations, fissile self-sufficiency for efficient utilization of uranium resources, autonomous load following making it suitable for small or immature grid applications, and a high degree of passive safety further supporting deployment in developing nations. In FY 2006, improvements have been made at ANL to the pre-conceptual design of both the reactor system and the energy converter which incorporates a supercritical carbon dioxide Brayton cycle providing higher plant efficiency (44 %) and improved economic competitiveness. The supercritical CO2 Brayton cycle technology is also applicable to Sodium-Cooled Fast Reactors providing the same benefits. One key accomplishment has been the development of a control strategy for automatic control of the supercritical CO2 Brayton cycle in principle enabling autonomous load following over the full power range between nominal and essentially zero power. Under autonomous load following operation, the reactor core power adjusts itself to equal the heat removal from the reactor system to the power converter through the large reactivity feedback of the fast spectrum core without the need for motion of control rods, while the automatic control of the power converter matches the heat removal from the reactor to the grid load. The report includes early calculations for an international benchmarking problem for a LBE-cooled, nitride-fueled fast reactor core organized by the IAEA as part of a Coordinated Research Project on Small Reactors without Onsite Refueling; the calculations use the same neutronics computer codes and methodologies applied to SSTAR. Another section of the report ...
Date: June 23, 2008
Creator: Sienicki, J. J.; Moisseytsev, A.; Yang, W. S.; Wade, D. C.; Nikiforova, A.; Hanania, P. et al.
Partner: UNT Libraries Government Documents Department