[yeknoda]

PWR pressure is on order 2-3x higher than an HTGR, so that’s a 2-3x thicker vessel. So good savings there

[pfdietz]

Cost of a pressure vessel is roughly proportional to pressure x volume. HTGR doesn't come out on top by that metric.

Thickness of a pressure vessel wall is proportional to pressure x linear dimensions of the pressure vessel, increasing at a given pressure as the vessel is scaled up.