Real-time On-line Decision Support System Research Articles

Emergency Decision Support Techniques for Nuclear Power Plants: Current State, Challenges, and Future Trends

Emergency decision support techniques play an important role in complex and safety-critical systems such as nuclear power plants (NPPs). Emergency decision-making is not a single method but a framework comprising a combination of various technologies. This paper presents a review of various methods for emergency decision support systems in NPPs. We first discuss the theoretical foundations of nuclear power plant emergency decision support technologies. Based on this exposition, the key technologies of emergency decision support systems in NPPs are presented, including training operators in emergency management, risk assessment, fault detection and diagnosis, multi-criteria decision support, and accident consequence assessment. The principles, application, and comparative analysis of these methods are systematically described. Additionally, we present an overview of emergency decision support systems in NPPs across different countries and feature profiles of prominent systems like the Real-Time Online Decision Support System for Nuclear Emergencies (RODOS), the Accident Reporting and Guiding Operational System (ARGOS), and the Decision Support Tool for Severe Accidents (Severa). Then, the existing challenges and issues in this field are summarized, including the need for better integration of risk assessment, methods to enhance education and training, the acceleration of simulation calculations, the application of large language models, and international cooperation. Finally, we propose a new decision support system that integrates Level 1, 2, and 3 probabilistic safety assessment for emergency management in NPPs.

JRODOS customization for Pakistan and assessment of the consequences of a hypothetical nuclear accident

Since the Chernobyl disaster in 1986, decision support systems and modelling tools have been utilized in response to nuclear and radiological emergencies. The java-based real-time online decision support system (JRODOS) is a decision support tool that can be utilised in response to an emergency in managing off-site radiological consequences. This article documents the customization and use of JRODOS for Pakistan. JRODOS was tailored to the local Pakistan conditions, and a case study of a theoretical nuclear power plant accident was used to assess JRODOS’s feasibility as a decision support tool. A worst-case probabilistic accident scenario was used to identify zones and areas where urgent protective actions, early protective actions and food restriction and other response actions could be required. The areas and distances identified for the implementation of protective and response actions for such a hypothetical accident were found to be in agreement with the emergency planning zones and distances suggested by the International Atomic Energy Agency (IAEA). Additionally, the implications of meteorological and source term input parameters on predicting the radiation doses to members of the public were investigated. It was identified that the output of such tools strongly depends on the availability and accuracy of the input parameters, such as radioactive release and meteorological data. Limitations and uncertainties associated with these tools need to be considered in deciding on protective and other response actions in response to a nuclear accident. As established by the IAEA, protective and other response actions need to be applied on a graded approach, taking into account the protection strategy and uncertainties and limitations in the available information and criteria, based on the conditions at the facility and off-site.

ESTIMATION OF RADIOLOGICAL CONSEQUENCES FOR A HYPOTHETICAL RADIOACTIVE RELEASE AT CERNAVODA NPP

An analysis regarding the release and atmospheric transport ofradionuclides in case of a hypothetical nuclear incident at Cernavoda Nuclear Power Plant was performed in the present paper. For that purpose, the computer code JRodos (Real-Time Online Decision Support System for Offsite Emergency Management in Europe) was implied.

An approach for radiological consequence assessment under unified temporal and spatial coordinates considering multi-reactor accidents

The current approaches and computer code systems for radiological consequence assessment of nuclear accidents have still gaps in assessing consequences of nuclear accidents involving multiple reactors, since multi-reactor accidents should be treated in one unique temporal and spatial system. This paper presents an approach to unify and generalize temporal and spatial coordinates for the consequence assessment of multi-reactor accidents. A code system named Advanced Radiological Consequence Assessment Toolkit (ARCAT) was developed accordingly. ARCAT is intended to support in particular emergency preparedness studies at the nuclear power plant level.To verify ARCAT, an analysis was carried out comparing ARCAT with MELCOR Accident Consequence Code System (MACCS), and the Java-based Real-time Online Decision Support System (JRodos). The results indicate that ARCAT is comparable to MACCS. This means that ARCAT is suitable for offsite radiological consequence assessment and able to support emergency preparedness including cliff-edge effects. Further to this, the effects of a unified temporal and spatial coordinate system are discussed to better recognize the impact of such special characteristics of multi-reactor accidents. A preliminary application based on ARCAT is presented, in which the plume emergency planning zone (PEPZ) for a hypothetical site with two reactors is developed. Finally, potential challenges and further research plans are discussed.

Treatment, logistical, and cost burden of prior authorization in community practice.

164 Background: Prior authorization (PA) process is complicated and labor intensive and with limited resources available to community practices, significant opportunity to reduce the costs of therapy exists by transforming this decision support process while being compliant with guidelines Methods: We retrospectively evaluated 123 patients between November 2016 and June 2016 across our three rural oncology practices with no dedicated in-house pharmacy. An established PA workflow involved two physicians, 1 nursing staff and 2 clerical staff involved in the process to manage PA for high cost imaging (PET/CT/MRI) or after a high-risk/cost prescription was initiated by a medical provider to a local pharmacy, specialty or mail-order pharmacy. Two Physicians determined strength of concordance with National Comprehensive Cancer Network (NCCN) guidelines. We examined approval rates, method of communications, time to approval and whether these variables were associated treatment delay and insurance provider Results: Eight decision steps were necessary to obtain a PA. Forty-nine Medicare (39%), 21 managed Medicaid (17%), 29 commercial insurance (23.5%) and 14 commercial insurances (11%) required PA mostly for targeted therapy (29%), oral chemotherapy (28%), PET/CT (24%). Approval rate was 94.3% on first attempt with only 1.6% being denied after an appeal process. 89% concordance with NCCN guidelines was seen. Median time to start treatment was 4 working days (Mean 4.7; Range 0-18 days). PA requests were associated with greatest delay in approval time with managed Medicaid (7 v 1.51 days; p < 0.0001) compared to Medicare, when specialty pharmacy was used (5.2 v 2.3 days p < 0.03) and when fax was used versus online (4.1 v 2.3 days p < 0.02). Conclusions: The impact of the PA process on care delivery and cost reduction are not clear. Current process is particularly burdensome on small practices especially given the high approval rates. Significant opportunity exists to reduce the inefficiency of this system using a computer algorithm-based PA using real-time online decision support system using NCCN guideline concordance

Comparative Analysis of Calculation Possibilities of MACCS and RODOS Computer Codes for Emergency Response and Analysis of Radiation Consequences of Severe Accidents at NPPs

The paper presents a brief description of the Real-time On-line Decision Support System (RODOS) and MELCOR Accident Consequence Code System (MACCS) and evaluates the application of these codes for assessment of radiation impact on the public and environment in case of a severe accident at NPP in real time mode. The experts performed comparative analysis of results obtained from calculations using RODOS, WinMACCS and HotSpot codes. In the framework of the research, the chosen comparative criteria were assessed: total effective dose, thyroid equivalent dose, skin equivalent dose, I-131 and Cs-137 ground concentration at different distances up to 50 kilometers from the source of release.

Probabilistic risk assessment from potential exposures to the public applied for innovative nuclear installations

Potential exposures are those that may occur as a result of unanticipated operational performance or accidents. Potential exposure situations are probabilistic in nature because they depend on uncertain events such as equipment failure, operator errors or external initiators beyond the control of the operator. Consequently, there may exist a range of possible radiological impacts that need to be considered. In this paper a Level 3 Probabilistic Safety Assessment (PSA) for a hypothetical scenario relevant to Innovative Nuclear Energy Systems (INS) was conducted using computer code MACCS (MELCOR Accident Consequence Code Systems). The acceptability of an INS was analyzed taking into account the general requirement that relocation or evacuation measures must not be necessary beyond the site boundary. In addition, deterministic modeling of the accident consequences for the critical meteorological conditions was carried out using the JRODOS decision support system (Real-time On-line Decision Support system for off-site emergency management in Europe). The approach used for dose and risk assessment from potential exposure of accidental releases and their comparison with acceptance criteria are presented. The methodology described can be used as input to the licensing procedure and engineering design considerations to help satisfy relevant health and environmental impact criteria for fission or fusion nuclear installations.

Knowledge database and case-based reasoning

Nuclear emergencies are characterised by severe disruptions in society's functionality and adverse impacts on human, environment and economy. Decision-making in times of such crises is complex and usually accompanied by acute time pressure. Environment can change rapidly and decisions may have to be made based on uncertain information. IT-based decision support can systematically help to identify response and recovery measures, especially when time for decision-making is sparse, when numerous options exist or when events are not completely anticipated. This paper reviews the case- and scenario-based approach implemented in the so-called analytical platform to support the management of nuclear events in different accident phases. Important information needed for decision-making as well as approaches to reusing experience from previous events and the fictitious scenarios calculated by Java version of the Real-time On-line Decision Support System are discussed. Suitable management options based on similar historic events and scenarios might be identified to support disaster management.

A radio frequency identification and sensor-based system for the transportation of food

The damage caused by the degeneration of the quality of perishable products usually results in a great loss to transportation enterprises. To improve the delivery system for perishable products, a real-time monitoring and online decision support system with Radio frequency identification (RFID), a sensor network and a decision rule base has been developed in this study. First of all, the value degeneration process is described, using several mathematical models for handing different ways of perishing. Based on the mathematical models, and data from RFID and the sensor network, the quality of the goods can be predicted by the forecast module. When something abnormal occurs, the warning function will send an alarm signal to the users, then, the rule-based decision module will provide the user with suggestions as how to cope with the abnormality. The results from the simulation have shown that the monitoring and decision support system is an efficient tool for reducing the transportation losses of perishable products for the enterprises in cold chain.

Overview and main achievements of the EURANOS project: European approach to nuclear and radiological emergency management and rehabilitation strategies

In June 2009, the 5-year multi-national project EURANOS, funded by the European Commission in its 6th Framework Programme, reached its end, achieving most of the objectives addressed in the work programme. Partners from 23 European countries integrating 17 national emergency management organisations with 33 research institutes, aimed to enhance the preparedness for Europe’s response to any radiation emergency and long term contamination. Three handbooks to assist national and local authorities in the management of contaminated food production systems, inhabited areas and contaminated drinking water resources in Europe were developed in conjunction with a wide range of European stakeholders. Further guidance was prepared to support the decision making team in the lifting of early phase countermeasures. A governance framework for the sustainable rehabilitation of long term contaminated territories was developed and tested in France and in Norway. Considerable progress was made in developing a consistent set of models for calculating the best estimate of the current radiological situation in both contaminated agricultural and inhabited areas. These models were integrated in both the ARGOS and the RODOS decision support systems. Decision aiding components were improved to support the selection of management options with the help of multi criteria decision analysis procedures. A mass consistent wind field model was implemented together with a particle model for complex terrain. The migration of RODOS (Real-time On-line Decision Support System) to the operating system LINUX was completed. RODOS was completely re-engineered, taking into account the users’ recommendations from the demonstration projects and feedback from its operational use. This new version will build the kernel for the operational RODOS release in 2010 and new research activities related to the future improvement of RODOS.

Objectives and achievements in the first four years of the EURANOS project: European approach to nuclear and radiological emergency management and rehabilitation strategies

The 5-year multi-national project EURANOS, funded by the European Commission, started in April 2004. Integrating 17 national emergency management organisations with 33 research institutes, it brings together best practice, knowledge and technology to enhance the preparedness for Europe's response to any radiation emergency and long term contamination. After four years of operation the following achievements can be stated. Two handbooks to assist national and local authorities in the management of contaminated food production systems and inhabited areas in Europe have been developed in conjunction with a wide range of European stakeholders. A governance framework for the sustainable rehabilitation of long term contaminated territories has been developed and tested in France. Its implementation in Norway has started. A consistent methodology for calculating the best estimate possible of current radiological situation in both contaminated agricultural and contaminated inhabited areas has been developed. The migration of RODOS (Real-time On-line Decision Support System) to the operating system LINUX is completed. A mass consistent wind field model was implemented together with a particle model for complex terrain. A complete re-engineering of the system has started aiming to incorporate all the user's recommendations collected within the demonstration projects and the operational use of the system in emergency management organisations.

Multi-criteria decision support and evaluation of strategies for nuclear remediation management

Environmental emergency situations can differ in many ways, for instance according to their causes and the dimension of their impacts. Yet, they share the characteristic of sudden onset and the necessity for a coherent and effective emergency management. In this paper we consider decision support in the event of a nuclear or radiological accident in Europe. RODOS, an acronym for real-time on-line decision support system, is a decision support system designed to provide support from the early phases through to the medium and long-term phases. This work highlights the role of multi-criteria decision analysis (MCDA) within RODOS in ensuring the transparency of decision processes within emergency and remediation management. Special emphasis is placed on the evaluation of alternative remediation or countermeasure strategies using the multi-criteria decision support tool Web-HIPRE in scenario focused decision making workshops involving different stakeholder and expert groups. Decision support is enhanced by a module that generates natural language explanations to facilitate the understanding of the evaluation process, therefore contributing to the direct involvement of the decision makers, with the aim of increasing their confidence in the results of the analyses carried out, forming an audit trail for the decision making process and improving the acceptability of the system as a whole.

Multi-criteria decision support and stakeholder involvement in emergency management

Decision-making in emergency management involves many parties with different views, responsibilities and interests for which a consensus must be found. Multi-Criteria Decision Analysis (MCDA) can help to ensure transparency in such decision processes. This paper describes the application of MCDA in nuclear emergency and remediation management and the experiences gained from conducting moderated decision-making workshops. The workshops were based on a hypothetical nuclear accident scenario generated by the real-time online decision support system, RODOS, for nuclear emergency management. Focusing on the evaluation of long-term countermeasures, the multi-criteria decision support software, Web-HIPRE was used to guide and support the participating decision-makers, stakeholders and experts during the decision-making process in the moderated discussion. This software has been integrated into the RODOS system. In addition to identifying the factors driving decision-making in the context of nuclear emergency management, issues for further development of methodology and decision support tools were determined.

POSEIDON/RODOS models for radiological assessment of marine environment after accidental releases: application to coastal areas of the Baltic, Black and North Seas

In the framework of the developments of the European system RODOS (Real-time On-line DecisiOn support System) for emergency response to nuclear accident, the computer code POSEIDON, that was developed to assess the radiological consequences of radioactive releases into marine environment, was adapted to cope with emergency conditions, in situations of radioactive discharges into the oceans from direct deposition from the atmosphere, sunken ships and containers, from discharges of rivers and estuaries and from coastal run-off. Based on the box model developed within the ‘Marina’ project, POSEIDON can calculate the dose effects from radionuclide releases in the coastal waters of Europe integrated over long time periods. A dynamic food chain model was implemented to deal with the short-term dynamical uptake of radioactivity by specific marine plants and organisms. POSEIDON has been installed on a UNIX platform to be fully compatible with RODOS input/output databases and on a Windows platform with an interface based on web technology. The 3D hydrodynamic model THREETOX is a part of the POSEIDON/RODOS system. It has been applied to coastal areas of the Baltic Sea, the Black Sea, and the North Sea, to derive the parameters for a flexible system of well-defined model compartments to be adapted to emergency conditions. The activity concentrations in water and in the marine food web were calculated by means of POSEIDON for radioactive fallout resulting from bomb testing, from the Chernobyl accident, and from routine discharges from nuclear facilities. POSEIDON’s model results were compared with measurement data, and with calculation results from THREETOX. The model results agreed with the measurement data sufficiently.

Hydrological dispersion module of the decision support system RODOS

The Hydrological Dispersion Module (HDM) of the RODOS (real-time on-line decision support) system for nuclear emergency management in Europe is under development at IMMSP Ukraine; at NRG, The Netherlands; at FZK, Germany; at SPA TYPHOON, , Russia; at IPEP, Minsk, Belarus, and NCSR Demokritos, Greece. Initial testing and customisation work was performed by NPPRI, Slovakia. The hydrological model chain of RODOS was outlined covering processes, such as runoff of radionuclides from watersheds following deposition from the atmosphere (RETRACE), transport of radionuclides in river systems (1-D model RTvTOX) and the radionuclide behaviour in lakes, reservoirs and estuaries (radioecological box model LAKECO, 2-D model COASTOX, and 3-D model THREETOX). The main aim of HDM is the prediction of the dispersion of radionuclides in aquatic systems following atmospheric fallout. HDM provides also the supplementary possibility to simulate the transport of radionuclide transport in aquatic systems following a direct release of radioactivity into the surface waters. In the RODOS system, the calculation results of HDM are transferred to both the aquatic food chain model (LAKECO) and to the dose module (FDMA) to assess the main exposure pathways. To apply HDM, the set of hydrological models have to be adapted together with the RODOS system taking into account the specific properties of the hydrological systems in the areas of interest

Using WOFOST crop model for data base derivation of tritium and terrestrial food chain modules in RODOS

The European Commission Project RODOS is developing a coherent methodology for a Real-time On-line Decision Support System for Nuclear Emergency across Europe. Within this system there is a special module to model the transfer of triated water from releases to terrestrial foods. In order to model the transfer of tritiated water from air to various plants, the conversion to organically bound tritium, and the partition to edible parts of the plant, both the mean dynamics of leaf area index and a physiological description of canopy photosynthesis are required. The WOFOST crop growth model has been selected as a basis for deriving tritium transfer dynamics to plants. Its ability to reproduce site-specific biomass growth of various plants (not only from Europe) is demonstrated in this paper, as well as its compatibility to other photosynthesis models. We have tested that this model can simulate limited fertilisation situations via the adaptation of two important parameters. After adaptation of model parameters to site- specific plant growth data, multi-annual mean dynamics can be obtained using meteorological data for subsequent years.

Generating feasible strategies in nuclear emergencies—a constraint satisfaction problem

RODOS is a Real-time On-line DecisiOn Support system intended for use throughout a nuclear emergency, extending into the longer term. In this paper we concentrate on the early phases in which decisions on sheltering and evacuation have to be taken quickly and under many pressures. RODOS is designed to assist off-site emergency management by formulating and structuring the evaluation of possible combinations of countermeasures. Because there can be very many such combinations to be evaluated, an expert system has been developed to eliminate those that do not satisfy certain constraints depending on factors such as the wind direction and evacuation practicalities. The system uses the ILOG solver constraint satisfaction package and its high-level programming library to reduce the number of strategies to a manageable fraction. This allows a later careful evaluation of the remaining alternatives.

The Implementation of RODOS in Belarus, Russia and Ukraine, and Future Perspectives

Broad agreement has been achieved between institutes and institutions in the European Union, Belarus, Russia and the Ukraine to cooperate in the development of the Real-time On-line DecisiOn Support System (RODOS), a decision support system for general application in Eastern and Westem European countries. The ultimate goal of this joint venture is the integration of an operational RODOS system into the national emergency management arrangements. To provide a standard platform for the common R&D work, the hardware and software components of RODOS have been implemented at SPA Typhoon, Obninsk, Russia, the Cybernetics Centre, Institute of Mathematical Machines and System (IMMS CC), Kiev, Ukraine, and the Centre for Radiological and Environmental Monitoring (CREM) of the Committee on Hydrometeorology, Minsk, Belarus. The activities of the CIS institutes of generating their RODOS teams, educating and training the personnel involved and organising cooperation with other institutes for securing access to meteorological and radiological monitoring data, national geographical information and specific expertise necessary to adapt models and data of the RODOS system to local, regional and national conditions are presented. Examples are given of RODOS case studies and the application of RODOS to analyses of real emergency situations.

The RODOS System: Decision Support for Off-Site Emergency Management in Europe

The integrated and comprehensive Real-time On-line DecisiOn Support system, RODOS, for off-site emergency management of nuclear accidents is being developed with support of the European Commission and the German Ministry of Environment. Designed as a generic tool, the RODOS system will be applicable from the very early stages of an accident up to many years after the release and from the vicinity of a site to far distant areas. Decision support will be provided at various levels, ranging from the largely descriptive, with information on the present and future radiological situation, to an evaluation of the benefits and disadvantages of different countermeasures' options. A large number of West and East European institutes are involved in its development to operational use. This paper gives an overview of the structure, the content, the main functions and the development status of the RODOS system and discusses its potential role for improving emergency response in Europe.

LAKECO: Modelling the Transfer of Radionuclides in a Lake Ecosystem

The model LAKECO has been developed to be one of the aquatic models within the emergency decision support system RODOS (Real-Time On-line Decision Support System for off-site emergency management in Europe). LAKECO is a dynamic model, able to predict the radionuclide levels in water, in sediments, and in fishery produce in various types of lake ecosystems. Sensitivity and uncertainty analyses demonstrate the dominant parameters. In order to develop a more flexible and applicable model, LAKECO has been modified and extended with process based sub-modules to assess these parameters, which increased the predictive power of the model. Subsequent validation tests with this new release showed a higher reliability of the model predictions. LAKECO will be integrated into RODOS and coupled to dose and countermeasure models to assess both the short and long-term radiological consequences due to the aquatic exposure routes in accident circumstances.