The PRR-1 initially operated as a critical reactor from 1963 to 1988 and the facility became dormant for 34 years.

[1] It was successfully operated from 1964 to 1984 and was utilized for training and research in nuclear science as well as for isotope production.

In 1984, the Philippine Atomic Energy Commission (PAEC; then name of the Philippine Nuclear Research Institute (PNRI)) decided to convert and upgrade the reactor into a 3 MW TRIGA Mark III reactor.

After its conversion, technical and administrative problems rendered the facility inoperable, which resulted in its extended shutdown.

[6] After 34 years of the PRR-1 being left unused, the commissioning process of the SATER began when it was loaded with 44 nuclear rods on June 20, 2022.