scholarly journals Optimization of Systems Repair Plans and Assessment of the Useful Life of Nuclear Power Plant Equipment

2020 ◽  
Vol 23 (4) ◽  
pp. 72-78
Author(s):  
Leonid I. Zevin ◽  
◽  
Hennadii H. Krol ◽  
Keyword(s):  
Power Unit ◽  
Nuclear Power ◽  
Structural Reliability ◽  
Optimization Method ◽  
Economic Feasibility ◽  
Planning System ◽  
Repair Costs ◽  
Reliability Indicator ◽  
Nuclear Power Unit ◽  
Useful Life

This paper presents a computer-aided method of planning the volumes of repairs of systems of nuclear power units and a method for calculating their gamma-percentile life. This planning is carried out on the basis of predicting the reliability indicator, the probability of no-failure operation for a certain time period, with the gamma-percentile life of the equipment being determined by solving the corresponding equations. The tasks considered are related to an important energy problem of extending the operation of nuclear power units. Its importance is determined mainly by economic feasibility: it is cheaper to assess the useful life of a nuclear power unit and, on this research basis, extend its operation, than create a new unit. It is also shown that the calculation of the probability of a radiation accident at a nuclear power unit is associated with the results of planning the repairs of its systems, with assessment of its useful life. An optimization problem is formulated: it is required to find such a plan for the volumes of repair of a system that, with limited repair costs, its reliability indicator for a given duration deviates least from the maximum permissible value. The solution to the problem is based on calculating the structural reliability of the system. A graphological image of the system is built in the form of a composition of graphological images of typical structures. After the reliability indicator of typical structures has been calculated, the structures are replaced with individual structural elements, which makes it possible to simplify the initial graphological image of the system in a computational scenario and calculate its reliability indicator. The determination of the repair volume is carried out by applying a version of the coordinate-wise optimization method. To assess the gamma-percentile life, a model is adopted, in which the recoverable equipment components have an unlimited life, although, of course, they "age", and the non-recoverable components spend their life up to the level when their replacement becomes conditioned by the violation of the requirement for the maximum permissible value of the system reliability indicator. Estimates of the gamma-percentile life of the equipment are calculated by planning system repairs on a sequence of intervals of annual energy production by a nuclear power unit.

scholarly journals Operating characteristics and peak regulation capability of AP1000 nuclear power unit

2021 ◽  
Vol 714 (4) ◽  
pp. 042033
Author(s):  
Yongqiang Che ◽  
Yisen Chen ◽  
Fengcai Zheng ◽  
Junshan Guo ◽  
Panfeng Shang
Keyword(s):  
Power Unit ◽  
Nuclear Power ◽  
Operating Characteristics ◽  
Nuclear Power Unit

Research on Negative Pressure Control Technology in NPP Reactor Building and its Application

2013 ◽  
Author(s):  
Jianghong Xie
Keyword(s):  
Power Unit ◽  
Negative Pressure ◽  
Nuclear Power ◽  
Pressure Control ◽  
Control Technology ◽  
Annular Space ◽  
Pressure System ◽  
Nuclear Power Unit ◽  
Reactor Building ◽  
Double Wall

The paper mainly elaborates the negative pressure control technology and commissioning approaches for double-wall containment of Russian WWER-1000 nuclear power units. It also carries out an analysis and research on the layered negative pressure technology in the containment. It mainly includes the following three parts: A Russian WWER-1000 nuclear power unit adopts the structure of double-wall containment for its Reactor building, with independent negative pressure systems for the containment and the annular space between the two walls. The paper mainly elaborates the control methods and limits requirements for the negative pressure in the containment and the annular space under the normal operation condition and in case of design basis accidents, with analysis and argumentation on the design function and operation requirements of the negative pressure system for the containment and the annular space. In the paper, the design philosophy of layered negative pressure and its feasibility study are analyzed from the aspects of radiated partition, air distribution of the negative pressure system and containment separator for layered negative pressure. The commissioning methods and technical requirements of negative pressure system in the Reactor building are described in the paper. Problems encountered during commissioning are also addressed and analyzed. Operations practices prove that the negative pressure control technology for double-wall containment of WWER-1000 nuclear power unit is advanced and reliable, which meets the requirements on nuclear air decontamination emission and radiation protection, and is worthy of study, research and reference.

Radiography Inspection Technology of CPR1000 Nuclear Power Unit Pressurizer

2014 ◽  
pp. 539-544
Author(s):  
Jingyun Hao ◽  
Dong Deng ◽  
Jing Wang ◽  
Shuangyin Wang ◽  
Xiongfei Hua
Keyword(s):  
Power Unit ◽  
Nuclear Power ◽  
Nuclear Power Unit

scholarly journals Modeling of flexible nuclear power unit operational modes in the mathematical model of the Ukraine’s power system daily electric load profile dispatching

2021 ◽  
Vol 2021 (1) ◽  
pp. 29-37
Author(s):  
T.P. Nechaieva ◽  
Keyword(s):  
Mathematical Model ◽  
Power System ◽  
Power Unit ◽  
Nuclear Power ◽  
Storage Systems ◽  
Electric Load ◽  
Load Profile ◽  
Load Rate ◽  
Nuclear Power Unit ◽  
The Mathematical Model

The use of large amounts of existing baseload NPPs capacities with a significant increase in renewable generation in the mathematical model of optimal dispatching of generating capacities of Ukraine’s power system leads to a significant surplus of electricity during peak power generation at solar PV’s, which necessitates additional sources of flexibility of the power system, such as battery electricity storage systems. The projects of new advanced nuclear power units provide for their use in flexible load modes with a maximum unloading of up to 50% of the rated capacity. Advanced NPP power units with small modular reactors are designed for even greater more maneuverable operation with possible unloading of up to 20% of rated capacity. The article presents approaches to modeling the use of NPP power units in variable load modes in the mathematical model of the optimal daily load schedule dispatching of Integrated Power System of Ukraine. The first approach is to model the operation of NPP power units similar to modeling the participation of cycling TPP units in covering the daily electrical load profile of the power system, in particular, changes in generation power in the range from minimum to nominal load levels, load rate. The second approach is to determination for each nuclear power unit of variants of modes of their hourly loading, the choice of one of which is made as a result of optimization. The modeling results showed that the choice of optimal flexible loading modes of new nuclear power units allows to provide the load balance of the power system almost completely with available capacities, including cycling TPP units, and the use of pump-storage generating units to transfer excess PV generation at peak hours of electricity consumption, which avoids the use of battery storage systems. Keywords: mathematical model of dispatching, operational mode, nuclear power unit, daily electric load profile, power system

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