Safety monitoring and reactor transient interpreter

For use in a nuclear reactor power plant, including a reactor vessel, said power plant having a number of first subsystems utilized for operating said plant during normal operating conditions, a number of second subsystems utilized for operating said plant during abnormal and accident operating conditions, and a control panel for displaying plant parameters relating to plant operation, a transient interpreter comprising:

• means (22) for logically combining critical ones of said plant parameters to thereby provide data as to normal, abnormal and accident plant conditions;
• first means (14), responsive to said combining means (22), for generating a primary output display comprised of primary output display (POD) data, said POD data containing information in summary form of selected ones of said critical plant parameters, said selected ones of said critical plant parameters comprising a first subset of said plant parameters, said first subset of said plant parameters relating to said first subsystems utilized for operating said plant during normal operating conditions said POD data including measured data corresponding to the net inflow or outflow of water to said reactor vessel as indicated by directly measured process instrumentation level meters;
• displaying means (9, 10, 11) for displaying data inputted thereto;
• second means (26) connected to said first means (14) and to said displaying means (9, 10, 11) for gating said primary output display, selectively under control of a first selection input (17), to said displaying means (9, 10, 11);
• third means (18) responsive to said combining means (22) for generating a plurality of secondary output displays (19),
• said third means including means for calculating reactor vessel water level based upon an analytical model of said reactor vessel and said core, said analytical model being based upon the integration of the inflow and outflow of water to said reactor vessel, reactor power, reactor pressure, and reactor water mass, to thereby provide calculated water level data,
• said secondary output displays (19) comprised of secondary output display (SOD) data, said SOD data comprising a second subset of said plant parameters relating to said second subsystems utilized for operating said plant during abnormal and accident operating conditions, said SOD data containing information in summary form of said second subset of said plant parameters, said SOD data including said calculated water level data which provides an operator with a secondary display during abnormal and accident operating conditions which is an alternative to said measured data available on said primary output display;
• fourth means (34) connected to said third means (18) and to said displaying means (9, 10, 11) for gating one of said secondary output displays (19), selectively under control of a corresponding one of said second selection inputs (28), to said displaying means;
• and,
• fifth means (16) operable by an operator, for selectively energizing and deenergizing said second selection inputs (28) and said first selection input (17) to thereby provide said operator with a display of only selected ones of said second subset of said plant parameters.

For use in a nuclear reactor power plant, including a reactor vessel, said power plant having a number of first subsystems utilized for operating said plant during normal operating conditions, a number of second subsystems utilized for operating said plant during abnormal and accident operating conditions, and a control panel for displaying plant parameters relating to plant operation, said plant including a water-cooled reactor core in a reactor vessel, the method comprising the steps of:

• A. generating primary information as to whether the core is covered and likely to remain covered, including information as to the status of those of said first and second subsystems needed to provide water to cool the core and maintain core integrity;
• said step of generating primary information including the steps of:
• determining the instantaneous water inventory of said reactor vessel by monitoring the parameters of those of said first and second subsystems that add water to said reactor vessel, and those of said first and second subsystems that take water away, to provide first data corresponding to the net inflow or outflow of water to said reactor vessel as indicated by directly measured process instrumentation level meters;
• converting said first data to measured water level data relative to the top of said reactor core;
• and,
• generating for display, a primary display, said primary display comprised of information corresponding to said instantaneous water inventory of said reactor vessel;
• B. generating secondary information which provides a secondary display comprised of information as to reactor vessel water inflow and outflow in ranked order which can be viewed selectively for more detailed information when an abnormal condition occurs;
• said step of generating secondary information including the steps of:
• calculating reactor vessel water level based upon an analytical model of said reactor vessel and said core, said analytical model being based upon the integration of the inflow and outflow of water to said reactor vessel, reactor power, reactor pressure, and reactor water mass, to thereby provide calculated water level data as an alternate to said measured water level data;
• setting said calculated water level data to be equal to said measured water level data periodically only during normal operation of said plant, so that said calculated water level is consistent with said measured water level data as indicated by said directly measured process instrumentation level meters;
• and,
• C. displaying with said primary information, a prompt message indicating that said secondary display should be selected for viewing.