[en] Even as the OSU TRIGA was being constructed, the plan to upgrade the reactor to 1 MW was adopted. A few months after the reactor went critical at 250 kW (March 1967), the necessary material to upgrade was purchased: a fourth fuelled follower control rod and drive, a fission chamber drive, and the modifications for the console. Additional fuel elements had been included in the original fuel purchase. The cooling system was designed for 250 kW operation and it was planned to be replaced with a 1 MW cooling system. The day-by-day schedule of upgrading is listed, showing the main items of work accomplished. If the trouble with the safety rod bearings and the central thimble bowing had not occurred, the entire upgrading could have been accomplished in about 15 working days. Subsequent operation has shown that, with a 250 kW cooling system: (a) 1 MW operation can be maintained for about 1 hr before the bulk water temperature reaches 48 deg. C, and about 1 more hour is required to cool the water back to 28 deg. C, (b) 500 kW operation can be maintained all day (8 hr), the bulk water temperature reaching an equilibrium of about 41 deg. C. It would obviously be more desirable to have a 1 MW cooling system, but until that time comes, many hours of useful operation can be obtained at power levels exceeding 250 kW using only a 250 kW cooling system. In addition the five different audible alarms were consolidated into a single annunciator system, and a Model 74126 Panastat by Panalarm was chosen