Graphite modification reduced molten LBE infiltration

What the study found: The modification process significantly improved the structural compactness of commercial nuclear graphite and increased its resistance to infiltration by molten lead-bismuth eutectic (LBE), a liquid metal coolant material.
Why the authors say this matters: The authors conclude that the approach may be a feasible way to obtain graphite coolant channel material suitable for lead-cooled fast reactors (LFRs), which are reactors cooled by liquid lead-based coolant.
What the researchers tested: The researchers modified commercial nuclear graphite using impregnation and pyrolysis with a polycarbosilane solution, then compared pristine and modified graphite using mercury infiltration and static molten LBE infiltration experiments.
What worked and what didn't: The modified graphite took in much less molten LBE than the pristine graphite under all infiltration pressures. The dense silicon carbide (SiC) coating formed from polycarbosilane also showed durable resistance during the molten LBE infiltration tests.
What to keep in mind: The abstract presents preliminary evidence from infiltration experiments on commercial nuclear graphite; broader limitations are not described in the available summary.

Key points

• Impregnation and pyrolysis with polycarbosilane improved the compactness of nuclear graphite.
• Modified graphite showed lower molten LBE infiltration than pristine graphite at all tested pressures.
• A dense SiC coating formed from polycarbosilane remained durable during the infiltration tests.
• The authors describe the method as a feasible route for graphite coolant channel material in LFRs.