Initial Argonne Sodium Draining Tests: Analysis of Test Results and Comparison with Water Draining Behavior

Technical Report · Mon May 21 04:00:00 EDT 2018

DOI:https://doi.org/10.2172/1490819· OSTI ID:1490819

Sienicki, James J. ^[1]; Chojnowski, David B. ^[1]; Boron, Ed ^[1]; Momozaki, Yoichi ^[1]

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1. Argonne National Lab. (ANL), Argonne, IL (United States)

Three initial sodium draining experiments have been carried out in which sodium was drained from a 0.46 m high 4.6 mm inner diameter vertical stainless steel tube wetted by the sodium representative of a sodium channel in a compact diffusion-bonded sodium-to-CO₂ heat exchanger. Prior to the startup of sodium testing, shakedown tests were conducted with water. In all three sodium experiments, the sodium drained efficiently from the channel. Sodium and water both drain efficiently from a 4.6 mm inner diameter vertical stainless steel tube. This is an important and good result for the design of compact diffusion-bonded heat exchanger sodium channels. Sodium drains more efficiently than water. This is also an important and good result for the design of compact diffusion-bonded heat exchanger sodium channels. The draining phenomena observed with sodium and water are significantly different. The draining of water involves an initial rapid slug draining phase followed by a linear rate draining phase followed by a slow draining phase involving draining of rivulets and drops. This behavior has previously been reported in the literature for viscous fluids. The draining of sodium involves an initial rapid slug draining phase but no discernable linear rate draining phase. There is a subsequent slow draining phase. However, unlike the slow draining phase with water that involves a number of rivulets and drops, the slow draining phase with sodium in two out of three sodium tests mainly involves a single discrete event in which a mass of sodium drains from the tube. This single discrete draining event encompasses most of the sodium mass remaining inside of the tube following the rapid slug draining phase. The existence of a single discrete draining event during the slow draining phase with sodium versus several rivulet and drop draining events with water is thought to simply reflect the fact that significantly lower mass fractions of liquid are left behind inside of the tube following the rapid slug draining phase with sodium relative to water. For the sodium tests, the progress of wetting of the stainless steel by sodium was monitored by means of the voltage drop across the tube outer diameter measured by pairs of opposing electrodes welded to the tube outer surface at three different elevations. The electrode data remarkably reveals phenomena during the sodium draining. The downward passage of the sodium slug trailing edge past each electrode was observed from which a mean slug trailing edge velocity could be determined. The subsequent slower increase in voltage drop suggests draining and thinning of a sodium film left behind upon the tube inner surface; wiggles in the voltage drop data are suggestive of the descent of waves on the film. It is thought that the draining sodium film collects as a mass likely near the lower end of the tube and detaches corresponding to the single discrete draining event observed in the load cell data. The minimum circular channel inner diameter for the draining of water and sodium without the formation of lenses that bridge the channel and may remain inside of the tube without draining is predicted with a correlation to be 2.2 mm. The highest priority for future sodium draining testing is to investigate other channel geometries such as a rectilinear channel or a semicircular channel.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1490819
• Report Number(s): ANL-ART--129; 144344
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
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