[gh02t]

Oak Ridge in particular is in DoE Office of Science. They do some national security work, but their primary focus is basic science. Some of the national labs do primarily do nuclear weapons related research, but not Oak Ridge. Frontier is only doing unclassified work, primarily basic science and engineering.

[dekhn]

Right; the labs most associated with nuclear work are LLNL and LANL. Both have had, IIRC, clusters configured for dual work- they could be partitioned between confidential and public work. The lab I wortked at, LBL, only did non-conf work but I know that LLNL took our codes and used them for nuclear simulations... errr, stockpile stewardship using multiphysics combustion codes.

[gh02t]

Oak Ridge does not do dual-use on the big leadership facilities, it's not really feasible with how they operate. I think Frontier can technically handle "moderate" data (e.g. export controlled), but not classified. It's meant for open science.

[omniglottal]

Didn't LANL get renamed to LANS?

[gh02t]

No, LANS was the name of the LLC that used to run LANL (which lost the contract a few years ago hence past tense), but the name of the lab itself is [still] LANL. The way the labs are run only a few people in the top leadership roles change if the management company running it changes; grossly oversimplifying they're basically interchangeable and come and go while the technical side of the labs themselves remain stable.