Excerpt from World Nuclear Association Website on Small and Medium Reactors:
The following reactor projects are utilizing LWR technology:
Light water reactors
US experience of small light water reactors (LWRs) has been of very small military power plants, such as the 11 MWt, 1.5 MWe (net) PM-3A reactor which operated at McMurdo Sound in Antarctica 1962-72, generating a total of 78 million kWh. There was also an Army program for small reactor development, and some successful small reactors from the main national program commenced in the 1950s. One was the Big Rock Point BWR of 67 MWe which operated for 35 years to 1997.
...[SMALL LWRs] mostly have the steam supply system inside the reactor pressure vessel ('integral' PWR design). All have enhanced safety features relative to current LWRs.
- Holtec (HI-SMUR)