A decision support system prototype including human factors based on the TOGA meta-theory approach

Mauro Cappelli, Fabrizio Memmi, Adam Maria Gadomski, Massimo Sepielli

Research output: Contribution to conferencePaper


The human contribution to the risk of operation of complex technological systems is often not negligible and sometimes tends to become significant, as shown by many reports on incidents and accidents occurred in the past inside Nuclear Power Plants (NPPs). An error of a human operator of a NPP can derive by both omission and commission. For instance, complex commission errors can also lead to significant catastrophic technological accidents, as for the case of the Three Mile Island accident. Typically, the problem is analyzed by focusing on the single event chain that has provoked the incident or accident. What is needed is a general framework able to include as many parameters as possible, i.e. both technological and human factors. Such a general model could allow to envisage an omission or commission error before it can happen or, alternatively, suggest preferred actions to do in order to take countermeasures to neutralize the effect of the error before it becomes critical. In this paper, a preliminary Decision Support System (DSS) based on the so-called (-) TOGA meta-theory approach is presented. The application of such a theory to the management of nuclear power plants has been presented in the previous ICAPP 2011. Here, a human factor simulator prototype is proposed in order to include the effect of human errors in the decision path. The DSS has been developed using a TRIGA research reactor as reference plant, and implemented using the LabVIEW programming environment and the Finite State Machine (FSM) model The proposed DSS shows how to apply the Universal Reasoning Paradigm (URP) and the Universal Management Paradigm (UMP) to a real plant context. The DSS receives inputs from instrumentation data and gives as output a suggested decision. It is obtained as the result of an internal elaborating process based on a performance function. The latter, describes the degree of satisfaction and efficiency, which are dependent on the level of responsibility related to each professional role. As an application, we present the simulation of the discussed error, e.g. the unchecked extraction of the control rods during a power variation maneuver and we show how the effect of human errors can affect the performance function, giving rise to different countermeasures which could call different operator figures into play, potentially not envisaged in the standard procedure.
Original languageEnglish
Publication statusPublished - 2012
Externally publishedYes
EventInternational Congress on Advances in Nuclear Power Plants 2012, ICAPP 2012 - , United States
Duration: 1 Jan 2012 → …


ConferenceInternational Congress on Advances in Nuclear Power Plants 2012, ICAPP 2012
CountryUnited States
Period1/1/12 → …


All Science Journal Classification (ASJC) codes

  • Energy Engineering and Power Technology
  • Nuclear Energy and Engineering

Cite this

Cappelli, M., Memmi, F., Gadomski, A. M., & Sepielli, M. (2012). A decision support system prototype including human factors based on the TOGA meta-theory approach. Paper presented at International Congress on Advances in Nuclear Power Plants 2012, ICAPP 2012, United States.