Enhanced operational safety of BWRs by advanced computer technology and human engineering

In BWR nuclear power plants, where unit capacity is increasing and the demand for assured safety is growing, it has become important for the information interface between man and machine to work smoothly. Efforts to improve man-machine communication have been going on for the past ten years in Japan. Computer facilities and colour CRT display systems are amongst the most useful new methods. Advanced computer technology has been applied to operating plants and found to be very helpful for safe operation. A display monitoring system (DMS) is in operation in a 1100 MW(e) BWR plant. A total combination test was successfully completed on the 'plant operation by displayed information and automation' system (PODIA) in February 1983 before shipment to the site. The objective of this test was to verify the improved qualification of the newly developed advanced PODIA man-machine system by this enlarged fabrication test concept. In addition, the development of special graphics displays for the main control room and technical support centre to assist operators in assessing plant safety and diagnosing problems is required to meet post-TMI regulations. For this purpose, a prototype safety parameter display system (called Toshiba SPDS) with two colour CRT displays and a computer (TOSBAC-7/70) was developed in 1981 as an independent safety monitoring system. The PODIA and SPDS are now independent systems, but their combination has been found to be more useful and valuable for nuclear power plant safety. The paper discusses supervisory and operational concepts in the advanced main control room including SPDS, and describes the PODIA and SPDS verification tests including the valuable experience obtained after improvements in the qualification of these systems had been made to satisfactory operational safety levels. (author)