Assessment of ASSERT-PV for prediction of critical heat flux in CANDU bundles

Assessment of ASSERT-PV for prediction of post-dryout heat transfer in CANDU bundles

“…They are calculated for a subset of the tests in each exercise, but the overall code bias, STD and RMS of the differences between the predicted and measured PDO sheath temperatures are also reported, and based on as many individual tests and measurements as possible (Rao et al, 2014b (Rao et al, 2014a). It is also revised by using the proper mixture density relaxation, wall temperature and heat transfer coefficient relaxation, and Jacobians related to the wall-to-fluid (Groeneveld, 2003) with enhanced data quality, and wider thermodynamic-quality range (Rao et al, 2014a) Subchannel size (diameter) correction exponent coefficient …”

“…The ASSERT code assessment for PDO calculations follows the guidelines specified in Rao et al 2014b. The following is a brief description:…”

“…• Select the qualified experimental data that are close to the ASSERT-intended application range. The ASSERT-intended application range for light water is identified in Rao et al 2014b. • Make the most use of the knowledge and experience accumulated in recent ASSERT code development and apply one model set to cover all CANDU bundle geometries and operating conditions.…”

“…Fig. 3 shows the two crept PT profiles of maximum diametric creep of 3.3% and 5.1% (Rao et al, 2014b).…”

“…Significant improvement has been confirmed for all key output parameters and over all three CANDU bundles. Nava-Dominguez et al 2014 andRao et al 2014b present the assessment results for the flow distribution and CHF predictions, whereas this paper focuses on the assessment of the PDO predictions. Since this paper is Part 4 of the four-paper series on ASSERT-PV 3.2, readers that are interested in the details of the code models and CHF predictions are advised to read also Rao et al, 2014a(Part 1), 2014b.…”