TY - GEN
T1 - An updated approach to the prediction of dryout and void fraction for RBWR bundles
AU - Zhao, X.
AU - Shirvan, K.
AU - Wu, Y.
AU - Kazimi, M. S.
N1 - Publisher Copyright:
Copyright © (2015) by American Nuclear Society All rights reserved.
PY - 2015
Y1 - 2015
N2 - Unlike a traditional square lattice BWR fuel bundle, the Resource-Renewable Boiling Water Reactor (RBWR) fuel bundle is a tight hexagonal lattice. The different geometry, combined with different operating conditions, demands a re-examination of the standard BWR thermal hydraulic models. For dryout, the previously recommended MIT correlation, which is based on the CISE-4 formulation, had large scatter when compared to experimental data in its validation database. In a new study, narrowing the range of hydraulic diameter and operating conditions and including critical heat flux (CHF) data for tubes and annuli were investigated. A new MIT correlation was derived but yielded very similar low MCPR (minimum critical power ratio) values as previously predicted for the RBWR designs. Another methodology, the 2006 CHF look-up table of Groeneveld was also used to predict dryout in RBWR type geometry. It was found that the effects of boiling length and axial power shape require further detailed investigation via higher fidelity simulations. For void fraction, experimental data and a three field model for annular flow regime revealed that the common drift flux approaches over-estimate the void fraction at smaller hydraulic diameters. The void fraction dependence on diameter below 10 mm requires further experimentation and high fidelity mechanistic simulations.
AB - Unlike a traditional square lattice BWR fuel bundle, the Resource-Renewable Boiling Water Reactor (RBWR) fuel bundle is a tight hexagonal lattice. The different geometry, combined with different operating conditions, demands a re-examination of the standard BWR thermal hydraulic models. For dryout, the previously recommended MIT correlation, which is based on the CISE-4 formulation, had large scatter when compared to experimental data in its validation database. In a new study, narrowing the range of hydraulic diameter and operating conditions and including critical heat flux (CHF) data for tubes and annuli were investigated. A new MIT correlation was derived but yielded very similar low MCPR (minimum critical power ratio) values as previously predicted for the RBWR designs. Another methodology, the 2006 CHF look-up table of Groeneveld was also used to predict dryout in RBWR type geometry. It was found that the effects of boiling length and axial power shape require further detailed investigation via higher fidelity simulations. For void fraction, experimental data and a three field model for annular flow regime revealed that the common drift flux approaches over-estimate the void fraction at smaller hydraulic diameters. The void fraction dependence on diameter below 10 mm requires further experimentation and high fidelity mechanistic simulations.
KW - Dryout
KW - Rbwr
KW - Tight lattice bundle
KW - Void fraction
UR - http://www.scopus.com/inward/record.url?scp=84962737307&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84962737307
T3 - International Topical Meeting on Nuclear Reactor Thermal Hydraulics 2015, NURETH 2015
SP - 365
EP - 378
BT - International Topical Meeting on Nuclear Reactor Thermal Hydraulics 2015, NURETH 2015
PB - American Nuclear Society
T2 - 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2015
Y2 - 30 August 2015 through 4 September 2015
ER -