Since the reform and opening up, the construction in all aspects of our country has achieved a rapid development, and especially the development of the industrial construction is also more prominent, so that each big ...Since the reform and opening up, the construction in all aspects of our country has achieved a rapid development, and especially the development of the industrial construction is also more prominent, so that each big city rapidly moves forward. But in the development at the same time, some of the issues are inevitable. The rapid development of the cities has attracted a large population, and there are more and more large factories, so that there is more and more pollution in the life and production, which brings greater security risks to the human life and health, and let the cities more difficult to manage. So how to solve these problems and make the cities develop better is a problem worth pondering.展开更多
Wastewater treatment plants （WWTPs） can represent risks source for human health and environment, due to the use of chemicals and substances produced by the treatment process. In particular, considering a conventiona...Wastewater treatment plants （WWTPs） can represent risks source for human health and environment, due to the use of chemicals and substances produced by the treatment process. In particular, considering a conventional urban wastewater treatment plant, two case studies have been considered in this paper： the phase of disinfection with Peracetic Acid （PAA）, used as reactant and the sludge anaerobic digestion, generating biogas. The aim of the experience is to find out some management suggestions that could make safer these sections of a WWTP.展开更多
The NPP （nuclear power plant） being vital objects of an energy infrastructure must be protected against malicious actions affecting their safety, and cyber security plays a key part in attaining this goal. The paper...The NPP （nuclear power plant） being vital objects of an energy infrastructure must be protected against malicious actions affecting their safety, and cyber security plays a key part in attaining this goal. The paper considers, implemented by the authors within the project of advanced digital control system for NPP with the reactor VVER-1000, a system of unauthorized access protection, partially built up on the technology of AA （active audit） and expert system. The AA technology is based on response of the system on deviation of current signature of the automated process control system from stable state rather than on a certain signature of attack and relies on the estimation of the behavioral models of the particular digital control system. The advent of active audit reflects the current situation in the digital control systems where complex distributed platforms are used to construct automated process control system. The active audit allows one to make the digital control system functionally closed, provided that it is determinate. The methodology of the active audit does not give u external （barrier） and traditional （password, antivirus） methods of unauthorized access protection. These methods can be used when it is appropriate to achieve a required protection level.展开更多
This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analys...This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analysis,especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large,aging fleet of NPPs. This paper addresses the overlap and relationship of structure aging to severe loading performance,with particular emphasis on containment structures.展开更多
The original internal flooding probabilistic safety analysis （PSA） study of Krsko Nuclear Power Plant （two-loop Pressurized Water Reactor （PWR） plant of Westinghouse design） was performed in mid nineties and lim...The original internal flooding probabilistic safety analysis （PSA） study of Krsko Nuclear Power Plant （two-loop Pressurized Water Reactor （PWR） plant of Westinghouse design） was performed in mid nineties and limited to reactor core damage risk （Level 1 PSA）. In 2003, it was, together with other safety and hazard analyses, subject to the Periodic Safety Review （PSR）. In the PSR, it was stated that methodological PSA approaches and guidelines have evoluted during the past decade and several observations were provided, concerning the area screening process, residual risk and treatment of plant damage states and risk from radioactivity releases （i.e., Level 2 PSA）. In order to address the PSR observations, upgrade ofKrsko NPP internal flooding PSA was undertaken. The area screening process was revisited in order to cover the areas without automatic reactor trip equipment. The model was extended to Level 2. Residual risk was estimated at both Level 1 and Level 2, in terms of core damage frequency （CDF） and large early release frequency （LERF）, respectively.展开更多
The permeability and sorptivity properties of the two prestressed concrete containment buildings （PCCBs） of a nuclear power plant in South China, which had been under operation for 5 years, were measured by using th...The permeability and sorptivity properties of the two prestressed concrete containment buildings （PCCBs） of a nuclear power plant in South China, which had been under operation for 5 years, were measured by using the autoclam permeability system. The air permeability, sorptivity and water permeability indexes of No.1 PCCB are smaller than or equal to 0.11 ln（102 Pa）/min, 0.98×10 ^7 m3/minl/2 and 1.93×10 ^7 m3/min1/2, respectively, and the air permeability, sorptivity and water permeability indexes of No.2 PCCB are smaller than or equal to 0.17 In（102 Pa）/min, 1.6×10 ^7 m3/min1/2 and 4.43 ×10 ^7 m3/min1/2, respectively. Based on the criteria for evaluating the protective quality of concrete structures in terms of their permeability and sorptivity properties, proposed by the research organization of the autoclam permeability system, the protective quality of No. 1 PCCB is still in very good grade and that of No.2 PCCB is not in very good grade but in good grade, and the in-service inspection of the protective quality of No.2 PCCB should be strengthened in the future.展开更多
This paper investigates the minimum inventory （MI） of human system interfaces （HSIs） （i.e. alarms, controls, and displays） for plant＇s safe operation and represents the analytic procedure on the MI of HSIs deve...This paper investigates the minimum inventory （MI） of human system interfaces （HSIs） （i.e. alarms, controls, and displays） for plant＇s safe operation and represents the analytic procedure on the MI of HSIs developed for the digital instrumentation and control （I＆C） equipments in the main control room （MCR）. The MI of HSIs in the MCR indicates the HSIs that the operator always needs available to： （1） monitor the status; （2） perform and confirm a reactor trip; （3） perform and confirm a controlled shutdown of the reactor; （4） actuate safety related systems; （5） analyze failure conditions of the normal HSIs; （6） implement the plant＇s emergency operating procedures （EOPs）; （7） bring the plant to a safe condition; （8） carry out those operator actions shown to be risk important by the probabilistic risk assessment （PRA）. The proposed analytic procedure on the MI of HSIs in this study can be used to （1） identify the MI of HSIs and their design requirements; and （2） address design requirements and implementation for the MI of HSIs. The contribution of this study is to describe the MI of HSIs needed to implement the plant＇s EOPs, to bring the plant to a safe condition, and to carry out those operator actions shown to be risk important by the PKA.展开更多
文摘Since the reform and opening up, the construction in all aspects of our country has achieved a rapid development, and especially the development of the industrial construction is also more prominent, so that each big city rapidly moves forward. But in the development at the same time, some of the issues are inevitable. The rapid development of the cities has attracted a large population, and there are more and more large factories, so that there is more and more pollution in the life and production, which brings greater security risks to the human life and health, and let the cities more difficult to manage. So how to solve these problems and make the cities develop better is a problem worth pondering.
文摘Wastewater treatment plants （WWTPs） can represent risks source for human health and environment, due to the use of chemicals and substances produced by the treatment process. In particular, considering a conventional urban wastewater treatment plant, two case studies have been considered in this paper： the phase of disinfection with Peracetic Acid （PAA）, used as reactant and the sludge anaerobic digestion, generating biogas. The aim of the experience is to find out some management suggestions that could make safer these sections of a WWTP.
文摘The NPP （nuclear power plant） being vital objects of an energy infrastructure must be protected against malicious actions affecting their safety, and cyber security plays a key part in attaining this goal. The paper considers, implemented by the authors within the project of advanced digital control system for NPP with the reactor VVER-1000, a system of unauthorized access protection, partially built up on the technology of AA （active audit） and expert system. The AA technology is based on response of the system on deviation of current signature of the automated process control system from stable state rather than on a certain signature of attack and relies on the estimation of the behavioral models of the particular digital control system. The advent of active audit reflects the current situation in the digital control systems where complex distributed platforms are used to construct automated process control system. The active audit allows one to make the digital control system functionally closed, provided that it is determinate. The methodology of the active audit does not give u external （barrier） and traditional （password, antivirus） methods of unauthorized access protection. These methods can be used when it is appropriate to achieve a required protection level.
文摘This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analysis,especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large,aging fleet of NPPs. This paper addresses the overlap and relationship of structure aging to severe loading performance,with particular emphasis on containment structures.
文摘The original internal flooding probabilistic safety analysis （PSA） study of Krsko Nuclear Power Plant （two-loop Pressurized Water Reactor （PWR） plant of Westinghouse design） was performed in mid nineties and limited to reactor core damage risk （Level 1 PSA）. In 2003, it was, together with other safety and hazard analyses, subject to the Periodic Safety Review （PSR）. In the PSR, it was stated that methodological PSA approaches and guidelines have evoluted during the past decade and several observations were provided, concerning the area screening process, residual risk and treatment of plant damage states and risk from radioactivity releases （i.e., Level 2 PSA）. In order to address the PSR observations, upgrade ofKrsko NPP internal flooding PSA was undertaken. The area screening process was revisited in order to cover the areas without automatic reactor trip equipment. The model was extended to Level 2. Residual risk was estimated at both Level 1 and Level 2, in terms of core damage frequency （CDF） and large early release frequency （LERF）, respectively.
基金Project(20050487017) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject (2009567) supported by China National Nuclear Corporation
文摘The permeability and sorptivity properties of the two prestressed concrete containment buildings （PCCBs） of a nuclear power plant in South China, which had been under operation for 5 years, were measured by using the autoclam permeability system. The air permeability, sorptivity and water permeability indexes of No.1 PCCB are smaller than or equal to 0.11 ln（102 Pa）/min, 0.98×10 ^7 m3/minl/2 and 1.93×10 ^7 m3/min1/2, respectively, and the air permeability, sorptivity and water permeability indexes of No.2 PCCB are smaller than or equal to 0.17 In（102 Pa）/min, 1.6×10 ^7 m3/min1/2 and 4.43 ×10 ^7 m3/min1/2, respectively. Based on the criteria for evaluating the protective quality of concrete structures in terms of their permeability and sorptivity properties, proposed by the research organization of the autoclam permeability system, the protective quality of No. 1 PCCB is still in very good grade and that of No.2 PCCB is not in very good grade but in good grade, and the in-service inspection of the protective quality of No.2 PCCB should be strengthened in the future.
文摘This paper investigates the minimum inventory （MI） of human system interfaces （HSIs） （i.e. alarms, controls, and displays） for plant＇s safe operation and represents the analytic procedure on the MI of HSIs developed for the digital instrumentation and control （I＆C） equipments in the main control room （MCR）. The MI of HSIs in the MCR indicates the HSIs that the operator always needs available to： （1） monitor the status; （2） perform and confirm a reactor trip; （3） perform and confirm a controlled shutdown of the reactor; （4） actuate safety related systems; （5） analyze failure conditions of the normal HSIs; （6） implement the plant＇s emergency operating procedures （EOPs）; （7） bring the plant to a safe condition; （8） carry out those operator actions shown to be risk important by the probabilistic risk assessment （PRA）. The proposed analytic procedure on the MI of HSIs in this study can be used to （1） identify the MI of HSIs and their design requirements; and （2） address design requirements and implementation for the MI of HSIs. The contribution of this study is to describe the MI of HSIs needed to implement the plant＇s EOPs, to bring the plant to a safe condition, and to carry out those operator actions shown to be risk important by the PKA.
