Scaling analysis of the thermal hydraulic behavior in the secondary side of steam generator

This paper presents a multidimensional numerical analysis of the transient thermal-hydraulic response of a steam generator (SG) secondary side to a double-ended guillotine break of the main steam line attached to the SG at a pressurized water reactor (PWR) plant. A simplified analysis model is designed to include both the SG upper space, which the steam occupies and a part of the main steam line between the SG outlet nozzle and the pipe break location upstream of the main steam isolation valve. The transient steam flow through the analysis model is simulated using the shear stress transport (SST) turbulence model. The steam is treated as a real gas. To model the steam generation by heat transfer from the primary coolant to the secondary side coolant for a short period during the blow down process following the main steam line break (MSLB) accident, a constant amount of steam is assumed to be generated from the bottom of the SG upper space part. Using the numerical approach mentioned above, calculations have been performed for the analysis model having the same physical dimensions of the main steam line pipe and initial operational conditions as those for an actual operating plant. The calculation results have been discussed in detail to investigate their physical meanings and validity. The results demonstrate that the present computational fluid dynamics (CFD) model is applicable for simulating the transient thermal-hydraulic responses in the event of the MSLB accident including the blowdown-induced dynamic pressure disturbance in the SG. In addition, it has been found that the dynamic hydraulic loads acting on the SG tubes can be increased by 2–8 times those loads during the normal reactor operation. This implies the need to re-assess the potential for single or multiple SG tube ruptures due to fluidelastic instability for ensuring the reactor safety.

Download Full-text

Particle deposition modeling in the secondary side of a steam generator bundle model

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2015.09.001 ◽

2016 ◽

Vol 299 ◽

pp. 112-123 ◽

Cited By ~ 3

Author(s):

Roman Mukin ◽

Abdel Dehbi

Keyword(s):

Steam Generator ◽

Particle Deposition ◽

Deposition Modeling ◽

Secondary Side

Download Full-text

Localized Corrosion of Nuclear Grade Alloy 800 Under Steam Generator Layup, Startup and Operating Conditions

AECL Nuclear Review ◽

10.12943/anr.2012.00003 ◽

2012 ◽

Vol 1 (1) ◽

pp. 13-20 ◽

Cited By ~ 5

Author(s):

Y. Lu

Keyword(s):

Corrosion Resistance ◽

Steam Generator ◽

Elevated Temperatures ◽

Chloride Concentration ◽

Operating Conditions ◽

Nuclear Grade ◽

Localized Corrosion ◽

Pitting Potential ◽

Alloy 800 ◽

Secondary Side

The localized corrosion resistance of nuclear-grade Alloy 800, which is one of the preferred steam generator (SG) heat exchange tube materials of CANDU and PWR reactors, was studied under simulated SG secondary side crevice chemistry conditions at ambient temperature as well as at elevated temperatures. Series of cyclic potentiodynamic polarization tests were performed to study the localized corrosion resistance of Alloy 800 as a function of chloride ion concentration in the SG crevice solution at 40°C, 150°C and 300°C. Based on the experimental results, empirical equations were provided for calculating the pitting potential of nuclear grade Alloy 800 in the SG secondary side crevice chemistries with different levels of chloride concentration at SG layup, startup and operating temperatures.

Download Full-text