Load-Follow Demonstrations Employing Constant Axial Offset Power-Distribution Control Procedures

Knowledge base expert system control of spatial xenon oscillations in pressurized water reactors

“…The usual way of monitoring for xenon oscillations is based on the Axial Offset (AO), where AO is defined as [10],…”

“…Based on the AO, operators follow certain instructions to keep the AO within permissible limits around a target AO. The target AO value is defined as the AO at steady state full power operation, typically -10 to 0 %, and the target band is usually defined as ±5 % of the target value [10].…”

“…Sipush [10] et al proposed the Constant Axial Offset Control (CAOC) strategy for load-follow operations utilizing continuous control to keep the AO within a target band. This heuristic procedure requires constant observation of AO monitors, and response with PLCRs when the AO tends to shift out of the target band.…”

“…This heuristic procedure requires constant observation of AO monitors, and response with PLCRs when the AO tends to shift out of the target band. The continuous attention of the operator required for this process may easily be distracted as it happened in a specific AO experiment [10]. Although the target band is not a safety limit, a drifting AO may create unnecessary power peaks.…”

“…After the spatial xenon oscillations were identified, the nuclear industry experi mentally studied the stability of reactors and the effectiveness of the proposed control strategies [10,17,18,19,20,21,22]. At the same time, there were several occurrences reported to the Nuclear Regulatory Commission [23], regarding controlled xenon os cillations in PWRs.…”