Design and replacement of the Ohio State University research reactor's safety system

The Ohio State University research reactor's (OSURR's) safety system was based on an electronic design of an electronic design of the 1950s. Due to difficulty in obtaining parts and excess downtime, it was decided to upgrade this system. Two avenues were pursued, each with a common goal of enhanced reliability and avoiding changes that would constitute unreviewed safety questions (pursuant to 10CFR50.59). First, available systems from reputable manufacturers were evaluated for integration into our system with emphasis on cost and expansibility. Second, designs were created, specific to the needs of OSURR's safety system, prototyped, and tested. After reviewing the performance and costs associated with the above systems, a compromise was reached between off-the-shell equipment and equipment designed in-house. The new system and experiences with the new safety system are discussed in the paper