Instrumentation Development and Validation for an Experimental Study of Steam Generator Tube Loading During Blowdown

A numerical analysis has been performed to simulate the transient thermal-hydraulic response to a main steam line break (MSLB) for the secondary side of a steam generator (SG) model equipped with a venturi-type SG outlet flow restrictor at a pressurized water reactor (PWR) plant. To investigate the effects of the flow restrictor on the thermal-hydraulic response of SG to the MSLB, numerical calculation results for the SG model equipped with the flow restrictor are compared to those obtained for an SG model without the restrictor. Both analysis models contain internal structures. The present computational fluid dynamics (CFD) model has been examined by comparing to a simple analytical model. It is confirmed from the comparison that the CFD model simulates the transient response of the SG secondary to the MSLB physically plausibly and minutely. Based on the CFD analysis results for both cases with or without the restrictor, it is seen that the intensities of the steam velocity and dynamic pressure are considerably attenuated in the SG model equipped with the restrictor comparing to the case in the SG model without the restrictor.

Effects of a Venturi-Type Flow Restrictor on the Thermal-Hydraulic Response of the Secondary Side of a Pressurized Water Reactor Steam Generator to a Main Steam Line Break

Moody

2016

Instrumentation Development and Validation for an Experimental Two-Phase Blowdown Facility

Hamouda

Weaver

Riznic

2016

An experimental facility was designed and built to study the loading on steam generator tubes during a blowdown. The facility used refrigerant R-134a and measurements were taken for static and dynamic pressures as well as tube loading and temperatures. Commissioning experiments indicated that the off-the-shelf dynamic pressure transducers and load cells could not take the mechanical and thermal shock loading caused by the blowdown and produced spurious results of no value. This paper presents the instrumentation problems found, explains why they occurred, describes the remedial procedures employed, and outlines the instrumentation validation methodologies developed. The success of the instrumentation development is demonstrated in a series of experiments designed to assess the rapid transient measurement system.

Evaluation of a Numerical Analysis Model for the Transient Response of Nuclear Steam Generator Secondary Side to a Sudden Steam Line Break

Min

Jeong

2016

This paper presents an evaluation of the applicability of a numerical analysis model to the transient thermal-hydraulic response of steam generator (SG) secondary side to blowdown following a steam line break (SLB) at a pressurized water reactor (PWR). To do this, the numerical analysis model was applied to simulate the same blowdown situation as in an available experiment which was conducted for a simplified SG blowdown model, and the numerical results were compared with the measurements. As a result, both are in reasonably good agreement with each other. Consequently, the present numerical analysis model is evaluated to have the applicability for numerical simulations of the transient phase change heat transfer and flow situations in PWR SGs during blowdown following a SLB.