Abstract: A display organized with the various components of a complex process represented by the rows, and selected parameters to be monitored listed in columns. The fields of the display which represent a particular “vital sign” for a particular component present two types of information: (1) alarms which indicate whether the parameter is in or out of limits and how close it is to failure; and (2) trends which indicate changes and types of changes, but do not pose a threat to the system. The alarms, in most part, are represented by solid colors. The trends are shown by the interface line between two contrasting colors or shades of colors defining the trend line and showing the direction of the trend and type of change.

Abstract: An information system for a complex plant which clearly presents to the operator, in parallel as alarms, abnormal process changes which the operator can, at his discretion, manually respond to either to prevent conditions from deteriorating further to the point where automatic protective actuations will be initiated or where automatic protective actuations have not been completed because of a malfunction or were completed but have not been successful. Such alarms are displayed on a dedicated alarm display panel which spatially groups components and subsystems to show appropriate relationships, with the alarm messages shown in the associated area of the display so that possible disturbance propagation can be foreseen. Messages related to uncompleted automatic protective actuations may include a list of faults which prevented completion of those actuations.

Abstract: A safety system grade dropped rod detection system for a pressurized water reactor (PWR) utilizes core exit thermocouples arranged in multiple trains and hot and cold leg RTDs to generate a safety system grade rod stop signal. The system generates from the temperature signals a relative power deviation (RD) and a curvature index (CI), which is the spatial second derivative of RD for each fuel assembly. The CI signatures not only provide rapid, reliable detection of dropped control rods, but also clearly identify failed and failing thermocouples.

Abstract: A method for monitoring operation of a process facility comprising the steps of storing at least one planned sequence of hypothesized plant states using multi-valued logic to define calculation of a congruence factor for each of the hypothesized plant states; wherein said storing step includes storing relationships between the multi-valued logic variables defined by a maximum value function when any of the multi-valued logic variables in a first relationship may be true and defined by an average function when all of the multi-valued logic variables in a second relationship are expected to be true; converting data from the process facility into values of multi-valued logic variables; wherein said converting step assigns to the multi-valued logic variables numerical values corresponding to likelihood of truth; calculating the congruence factor for each of the hypothesized plant states in the at least one planned sequence using the multi-valued logic variables; and identifying a current plant state by comparing

Abstract: A safety system grade dropped rod detection system for a pressurized water reactor (PWR) utilizes core exit thermocouples arranged in multiple trains and hot and cold leg RTDs to generate a safety system grade rod stop signal. The system generates from the temperature signals a relative power deviation (RD) and a curvature index (CI), which is the spatial second derivative of RD for each fuel assembly. The CI signatures not only provide rapid, reliable detection of dropped control rods, but also clearly identify failed and failing thermocouples.

Abstract: A nuclear reactor plant is provided in which the reactor coolant system contains a dissolved solution of enriched boric acid. The boron-10 to boron-11 atomic isotope ratio of the enriched boric acid solution is greater than 19.8:80.2 at the start of the reactor core cycle. The nuclear reactor plant design provides for minimal mixing between the reactor coolant solution containing the enriched boric acid solution and the natural boric acid solution used during refueling operations.

Abstract: A nuclear reactor plant is provided in which the reactor coolant system contains a dissolved solution of enriched boric acid. The boron-10 to boron-11 atomic isotope ratio of the enriched boric acid solution is greater than 30:70 at the start of the reactor core cycle. The nuclear reactor plant design provides for minimal mixing between the reactor coolant solution containing the enriched boric acid solution and the natural boric acid solution used during refueling operations.

Abstract: An apparatus for providing an inventory of an isotopically enriched acidic solution of an element that is capable of forming a water soluble weakly acidic solution at temperatures amenable to ion exchange and having a lower molecular weight isotope fraction and a higher molecular weight isotope fraction is disclosed. This apparatus includes at least two ion exchangers, each being temperature dependent with respect to their storage capacity of said lower and higher molecular weight isotopes, a hot tank containing a hot tank solution and a cold tank containing a cold tank solution both flow coupled to the ion exchangers. A first series of valves is selectively operable to direct the hot tank solution to one of the ion exchanger and to direct the cold tank solution to the other ion exchangers. A second series of valves is selectively operable to direct the flow from the ion exchangers to either the hot tank or the cold tank. An analyzer for sampling the solution is located upstream from the hot tank.

Abstract: A system for a process facility monitors the execution of a procedure in which steps are defined with associated conditions. Each condition is one of an initial condition, sequential condition or constraining condition. While constraining conditions are checked for violations during several steps, sequential conditions are checked only during an associated step. The sequential conditions may be transformed into constraining conditions for subsequent steps by setting a transform flag either prior to execution of the procedure or during execution of the procedure in response to an operator request. Once a transformable sequential condition has been met or the step associated therewith has been completed, an enable flag is set making the sequential condition a transformed condition which is checked at the same time as the predefined constraining conditions.

Abstract: The present invention is a detector assembly for a nuclear reactor which includes platinum detector segments (30-40) axially distributed end to end within a reactor assembly and vanadium detector segments (42-52) spatially congruent in the same assembly. The vanadium detectors calibrate the platinum detector signals to remove the flux contributions of fission products. A full length vanadium detector (62) and a full length platinum detector (90) can be substituted and used to determine the compensation for the platinum detector segments (30-40). The compensated platinum detector signals, wherein compensation consists of isolating that portion of the total platinum detector signal that is directly proportional to the current local heat deposition rate in the reactor fuel, can be used for reactor core protection purposes.

Abstract: The present invention is a system which determines nuclear reactor control rod axial position using a deviation signature database generated from a current or reference signal pattern produced by one or more strings of axially dispersed fixed incore detector sections in the reactor core. The deviation signature database is produced by assuming deviant axial positions for the control rods in the core, calculating expected detector signals for the assumed positions and storing the deviation of expected signals from a calibration reference along with corresponding assumed rod positions. The signature database is periodically updated to take into account changed core conditions. When a change in detector responses is detected the system performs a signature analysis of the deviations in the signature database using the current deviation from the reference to search for the closest match.

Abstract: A process and an apparatus are provided which separate the lower molecular weight isotope fraction from the higher molecular weight isotope fraction of an element which forms a water soluble acid at temperatures amenable to ion exchange. The separation is accomplished by shifting the equilibrium constants for absorption and desorption by temperature variations of the acidic solution. The process and apparatus are preferably employed to enrich a boric acid solution in its boron-10 isotope fraction by employing the use of ion exchange resins which are capable of thermally storing and releasing boron isotopes.

Abstract: The present invention is a system that diagnoses plant state in conditions where plant state cannot be precisely determined from sensor signals. If a state is diagnosed with certainty an appropriate plant procedure step display is provided to the operator. If not, the steps corresponding to the likely states are displayed to the operator ranked according to the likelihood of being in that state. The operator can select a step or a time out will result in the highest likelihood step being selected. An appropriate step display is then provided to the operator. The system can also indicate to the operator the consequences of allowing that plant state to continue as well as provide recommendations concerning the currently diagnosed state.

Abstract: The present invention is a computer based system supporting plant operators in caring out nearly routine operations. The computer based system monitors available plant instrumentation signals and processes the gathered information to detect satisfaction of initial conditions to the state change. Once the state change is started, the system then compares the sequence of observed changes in the plant with a preprogrammed sequence and alerts the operators to any undesirable deviations from the preplanned sequence by providing appropriate attention grabbing displays on a system monitor. The system also continuously monitors constraining conditions and alerts the operator when the system moves toward an undesired state. The system requires no input from the operator when the operation underway is following the prescribed sequence and minimal input from the operator when a deviation is detected. The system internally and automatically tracks the evolution of plant states during the nearly routine operations.

Abstract: The present invention is a system that updates a pressurized water reactor core model, or data file describing the core, periodically using measured values determinable from core instrumentation. The system starts with a calibrated model calibrated from a flux map and a boron concentration measurement both determined monthly. Reactor system measurements are performed and the model is updated from the measurements using a standard depletion calculation. Some of the measured values are also used to determine measured actual values of axial offset and pinch. Standard neutronics equations are used to calculate analytical values of axial offset and pinch from the model, and the measured and calculated values are compared. If a deviation beyond a certain magnitude is detected, buckling coefficients in the model are adjusted to compensate for model drift. The updated model is stored and a time-out period is entered until it is time for another drift compensation cycle to start.

Abstract: The present invention obtains enthalpy rise deviations in core power distribution using core exit thermocouples 18 and an inlet temperature detector 20. The enthalpy rise deviations are used to determine control rod position change relative a rod reference position. Because rod position change is linear with respect to enthalpy deviation, the change can be determined from the slope using the deviation. By adding the change to a reference rod position the actual rod position can be determined.

Abstract: A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

Abstract: A smart reactivity computer is disclosed that processes signals from multiple neutron detectors to generate values of regional core reactivity that are output to a strip chart recorder. The computer compares the regional reactivity values and, when the values are coincident for a period sufficient to satisfy a statistical fit test to a straight line, indicates to the operator that true core reactivity can be determined. The computer determines control rod worth by first fitting a straight line to the coincident portion of the reactivity values. The computer then determines intersections between the straight line and the reactivity value lines produced when the control rods are moved on both ends of the straight line. The difference between intersections for a single control rod movement line determines control rod worth for that movement.

Abstract: The present invention provides a power distribution synthesis system that uses a small number of local axial power distributions determined from less than a full complement of fixed incore neutron detectors and a power sharing map produced from a full complement of core exit thermocouple temperature signals to synthesize the full core power distribution. The localized tilt of the core is determined from the power sharing map and used to remove the tilt from the local distribution. The tilt adjusted local distribution is assigned to symmetric core locations where uninstrumented core power values are determined by interpolation. The interpolated, assigned and tilt corrected local distribution power values are transformed into the three dimensional power distribution using the tilt.

Abstract: The operator of a complex process facility is aided in executing step by step procedures by a computer based system which incorporates monitored plant data and interactive plant operator responses to prompts to progress step by step through selected procedures. At each procedure step the plant status is evaluated and a recommended course of action is identified. The results are displayed on a visual display device to provide operator guidance for executing the procedure in effect. Parallel process monitoring visually alerts the user to conditions not considered by the current step of the active procedure, and where the seriousness of the other condition warrants, provides procedure-based recommendations for priority action. The system can be accessed by multiple users at separate locations for coordinated execution of a single procedure or simultaneous execution of two different procedures.