The SNAP-10A reactor power system

[Marlin]

The SNAP-10A reactor power system

https://www.ans.org/news/article-5878/the-snap10a-reactor-power-system/

[Mounder]

SSFL developed SNAP-10 and SNAP-10A in Building 4024. They leveled the top of the building about 4 years ago. It had been largely decontaminated by Boeing over a decade before. DOE's contractor filled the subsurface part of the facility with soil and put a cover over it. It's slated to be dug up and D&Dd soon if the schedule hasn't changed.  Some of the empty in-ground fuel vaults are visible outside the facility.
It's a nice site to tour on weekends with Boeing's environmental folks. Lots of unique creatures and flora. Nice views of Malibu.
Not a single Area 4 building is left. Area 4 being DOE's responsibility. The tour also goes by the legacy Salt Reactor Area that famously had an overblown partial-meltdown.
https://www.nps.gov/articles/000/santa-susana-tour.htm
https://www.boeing.com/innovation/sustainability/santa-susana-field-laboratory/santa-susana-tours