DEVELOPMENT OF TEMPERATURE PROTECTIVE CIRCUITS FOR THE HNPF FUEL CHANNEL EXIT (Revised)

摘要

The HNPF plant protective system includes circuits with the function of precluding unsafe high temperature and sustained fast changes in fuel-channel coolant-exit temperatures, either in the increasing or decreasing direction. The development of the fuel-channel exit high temperature and rate change of temperature circuits resulted in a transistorized system of plug-in components of high reliability. The circuits have been designed, where possible, for fail-safe operation in case of component malfunction;and for ease of maintenance and calibration. In addition to providing shutdown or scram signals, these circuits also provide setback and alarm signals. The set points for scram, setback, and alarm are each independently adjustable. These circuits monitor an iron-constantan thermocouple located at the outlet of a fuel cluster in the reactor. In the actual protective system, three identical circuits are used in a 2-out-of-3 coincidence arrangement to enhance the overall reliability.