16.422 Human Supervisory Control Nuclear and Process Control Plants Massachusetts Institute of Technology
16.422 Human Supervisory Control Nuclear and Process Control Plants
Process Control plants 16.422 Continuous or batch processing Examples: Electricity generation(nuclear power plants), refineries, steel production, paper mills, pasteurization of milk Characterized by Large scale, both physically and conceptually Complex High risk High automation Remote vS direct manipulation of plant equipment
Process Control Plants 16.422 • Continuous or batch processing • Examples: Electricity generation (nuclear power plants), refineries, steel production, paper mills, pasteurization of milk • Characterized by: – Large scale, both physically and conceptually – Complex – High risk – High automation • Remote vs. direct manipulation of plant equipment
Three mile island 16.422 · March28th,1979 Main feedwater pump failure, caused reactor to shut down Relief valve opened to reduce pressure but became stuck in the open position No indication to controllers Valve failure led to a loss of reactant coolant water No instrument showed the coolant level in the reactor Operators thought relief valve closed water level too high High stress Overrode emergency relief pump
16.422 Three Mile Island • March 28th, 1979 • Main feedwater pump failure, caused reactor to shut down • Relief valve opened to reduce pressure but became stuck in the open position – No indication to controllers – Valve failure led to a loss of reactant coolant water • No instrument showed the coolant level in the reactor • Operators thought relief valve closed & water level too high – High stress – Overrode emergency relief pump
Three Mile island 16.422 Automation worked correctly Confirmation bias: people seek out information to confirm a prior belief and discount information that does not support this belief At TMl, operators selectively filtered out data from other gauges to support their hypothesis that coolant level was too high
Three Mile Island 16.422 • Automation worked correctly • Confirmation bias: people seek out information to confirm a prior belief and discount information that does not support this belief – At TMI, operators selectively filtered out data from other gauges to support their hypothesis that coolant level was too high
Process control human factors Challenges 16.422 Control room design Increasing automation requires cognitive support as opposed to manual control support Human-machine interface design · Team decision making Standardized procedures vs innovation Trust confidence
Process Control Human Factors Challenges 16.422 • Control room design • Increasing automation requires cognitive support as opposed to manual control support • Human-machine interface design • Team decision making • Standardized procedures vs. innovation • Trust & confidence