PWR PACTEL Small Break LOCA Experiment SBL-50 Calculation with TRACE Code (NUREG/IA-0518)

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Publication Information

Manuscript Completed: August 2019
Date Published: January 2020

Prepared by:
J. Vihavainen

Lappeenranta University of Technology
P.O. Box 20
FI-53851 Lappeenranta

K.Tien, NRC Project Manager

Division of Systems Analysis
Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

Prepared as part of:
The Agreement on Research Participation and Technical Exchange
Under the Thermal-Hydraulic Code Applications and Maintenance Program (CAMP)

Published by:
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

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TRACE is one of the main codes used for performing nuclear power plant thermal hydraulic safety analysis at present. Therefore, the importance of assessing the TRACE code capability to predict various thermal hydraulic transients in reactor systems becomes evident. One such transient that can occur small break loss-of-coolant-accident. The natural circulation is of particular interest for code assessment, as it requires the system code accurately predict temperature and density distributions throughout the system. Specific modeling capabilities are required for heat transfer and two-phase flow phenomena.

This research presents the assessment of the PWR PACTEL small break LOCA experiment SBL-50 with the TRACE V5.0 Patch 4. The PWR PACTEL facility is a modified version of the original PACTEL facility utilizing some parts of the original facility but also including completely new parts, i.e. loops and vertical steam generators (SG). The research focus with PWR PACTEL is set on the loop and vertical steam generator behavior in natural circulation conditions during small break LOCA event.

TRACE code was able to reproduce natural circulation phenomenon and small break LOCA conditions rather well. However, some discrepancies between the predicted variables and the experimental data suggests that further investigation of the TRACE modeling is necessary.

Page Last Reviewed/Updated Tuesday, March 09, 2021