Computers take control of China's 5MW test heating reactor

In 1984 work started on developing and building a 5MW test heating reactor (THR) at the Institute of Nuclear Energy Technology of Tsinghua University, China. The I and C system for the THR was developed at the same time. Although a fully computerized instrumentation and control (I and C) system was feasible and should perform substantially better than a conventional hard-wired system, its advantages were not yet fully appreciated by those heading the project or the authorities who were concerned about reliability. Lack of experience in using such systems was a real concern. The compromise design included a mixture in which the computers replaced conventional instruments wherever possible but not in performing or actuating protection functions for which a conventional protection system was provided. As the THR is a new type of reactor, it seemed appropriate to the designers initially to have the computer provide only monitoring functions. Its role will be extended to include control functions after sufficient operating experience is gained. (author)