An estimate of the order of magnitude of the explosion during a core meltdown-compaction accident for heavy liquid metal fast reactors: A disquieting result updating the Bethe–Tait model

Abstract

Criticality and recriticality considerations in heavy liquid metal fast reactors (HLMFRs) after a hypothetical core meltdown accident are discussed. Although many aspects of system behaviour in such scenarios can be deduced directly from the classical theory of sodium-cooled fast reactors (SFRs), certain ideas that have been accepted as true for SFRs cannot be extrapolated to HLM-FRs without sufficiently careful thought. In this paper, we are concerned, as in SFRs, with fuel compaction, but with one important difference: there would be no boiling of the surrounding heavy liquid metal pool. Utilizing a Bethe-Tait model, it is shown that, due to the power flattening effect of the heavy liquid metal, explosive excursions at least an order of magnitude higher than for SFRs in similar situations are conceivable. aaaaaaaaaaa aKeywords. hypothetical core disruptive accidents, heavy liquid metal reactor, recriticality. disassembly phase, Bethe-Tait model

Aluminum Oxide Ceramic Coatings on 316l Austenitic Steel Obtained by Plasma Electrolysis Oxidation Using a Pulsed Unipolar Power Supply

“…AISI 316L steel becomes a good choice of structural material for the fusion reactor in the future, owing to its excellent processability and high temperature stability, but the structural pipe fittings achieved by 316L stainless steel are easily corroded by a large amount of highly permeable and corrosive tritium in the operating environment of fusion reactor [22]. The world-wide acknowledged solution is to prepare alumina ceramic coatings on the inner surface of stainless-steel pipes, which cannot only guarantee the structure property of pipe systems, but also protect the pipes from the permeation and corrosion of tritium [12].Austenitic 316L steel has already been extensively used as a nuclear structural material and is among the materials selected for nuclear systems with Heavy Liquid Metals (HLM) [5,23] as lead or Lead Bismuth Eutectic (LBE) [24]. The use of HLM raises problems with the compatibility of materials in terms of corrosion and mechanical strength [25,26].…”

“…Austenitic 316L steel has already been extensively used as a nuclear structural material and is among the materials selected for nuclear systems with Heavy Liquid Metals (HLM) [5,23] as lead or Lead Bismuth Eutectic (LBE) [24]. The use of HLM raises problems with the compatibility of materials in terms of corrosion and mechanical strength [25,26].…”