Study On The Effectiveness Analysis Of Physical Protection System In Virtual Environment Of Nuclear Power Plants

A Physical Protection System(PPS)integrates people,procedures and protection devices for the protection and prevention of nuclear facilities and nuclear materials against theft,robbery or illegal transfer of nuclear materials,sabotage of nuclear facilities,and other malevolent human attacks,which applies in the construction,operation and decommissioning phases of Nuclear Power Plants(NPPs).With the deteriorating international anti-terrorism situation,more attention needs to be paid to the security of nuclear materials and nuclear facilities.It is importance to establish an effective system and method for evaluating the effectiveness of physical protection systems to improve the security capacity and ensure nuclear safety.This dissertation studies the PPS design,assessment and training,the research includes:(1)Three-dimensional modeling of PPS: Uing Unity 3D as a platform,the virtual reality technology is used to build a three-dimensional model of NPP physical protection system to realize the visual effect of physical protection device design.(2)Analysis of the effectiveness of PPS: Combining EASI with 3D model and generating Adversary Sequence Diagram(ASD)according to entity protection device,and then establishing the mathematical model of the effectiveness of PPS,The effectiveness of the PPS is evaluated for each intrusion path in the ASD to determine whether the physical protection system designed in the virtual environment meets the design requirements and to further analyze the sensitive parameters to identify the key factors to improve the PPS design.(3)Analysis of intrusion path of PPS: In view of the difficulty of enumerating every intrusion path in ASD graph in practical engineering practice,heuristic algorithm is used to realize the intelligent search of vulnerable path.The heuristic method is applied to the threedimensional model,and the intrusion path and the response path are analyzed through the threedimensional platform.At the same time,the heuristic approach helps nuclear power plant staff perform 3D simulation exercises.(4)Software reliability analysis of PPS: According to the logical structure of software code,a hierarchical model and mathematical model of software reliability are established,and then the software reliability model is transformed into a Bayesian network model,and the quantitative evaluation of software reliability according to the test result.The software reliability hierarchical modeling platform has been designed and developed to realize the functions of graphical modeling,automatic conversion of Bayesian network model,software reliability allocation,quantitative evaluation of software reliability,analysis of sensitive code block and sensitive path.(5)Insider threat assessment of PPS: A novel mothod is presented to correlate the insider threats and the failure mode of the PPS protection elements.Using the classical FMEA method to assess the failure mode of the protection elements and discuss the common cause failure of the protection elements.In the hypothetical condition,this dissertation qualitatively evaluates the insider threats on the basis of EASI method.(6)Virtual training of PPS: Propose Unified Modeling Language(UML)for the modeling of PPS training and the use of Defense-in Depth(DiD)risk monitor software as a security training platform.The designed regulations are translated into platform-supported the states and events by platform operation.The simulation training platform contributes to support the awareness of NPPs staffs and response forces on the PPS,as well as the simulation of the regulations after each update.This dissertation in the following areas made innovative achievements:(1)Present an integrated platform technology that uses Unity3 D engine for the comprehensively design,evaluation,and drill of the PPS under the virtual environment.(2)Propose heuristic algorithm to solve intrusion path and response path of PPS,and analyzed the effectiveness of physical protection system.As a 3D simulation platform of PPS in virtual environment,Unity 3D combines heuristic search algorithm to realize intelligent analysis of path of PPS.(3)Present the structural hierarchical modeling to analyze the software reliability of PPS and realize the software reliability allocation and analysis.Hierarchical modeling method can automatically identify the structure of software code and build code model.Through the software reliability distribution and analysis in each stage of the software life cycle,it can ensure software fault-free operation and improve the effectiveness of PPS.(4)Present a qualitative assessment method of insider threats and reduce the possibility of intrusion by insider.Analysis of internal staff access to key areas of authorization and detection staff and found that the weaknesses of staff management.By the research on the modeling layer,the analysis layer and the training layer of the PPS,this dissertation establishes an intergrated method for the design,analysis,and training of the PPS in the virtual environment.Virtual PPS can improve the overall awareness of NPPs staffs,help strengthen security capability in NPPs to prevent and resolve the threats.