The extended operation and life extension project of Embalse Nuclear Power Plant—an account from a regulator’s perspective

2022 ◽  
pp. 399-427
Author(s):  
Gerónimo Poletto ◽  
Reinaldo Valle Cepero
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Life Extension ◽  
Extended Operation

Study on the Interaction Between Safety-Related and Non Safety-Related Items in the Component Cooling Water System Room of the Qinshan Nuclear Power Plant in the Earthquake Condition

2020 ◽  
Author(s):  
Liang Zhang ◽  
Gang Xu ◽  
Yue Wang ◽  
Li Chen ◽  
Shao Chong Zhou
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Water System ◽  
Cooling Water ◽  
Life Extension ◽  
Main Body ◽  
Cooling Water System ◽  
The Impact

Abstract Safety-related items in nuclear power plants are now generally placed separately from the non-safety-related items, but it was not strictly required before. Therefore, it is very important to study whether the non-safety-related items will affect the safety-related items when they are dropped down in an earthquake situation, which determines the safety of a nuclear power plant and its future life extension applications. This research was based on the cooling water system room with the safety and non-safety related items installed together, as an example to study whether the non-safety-related items such as vent pipes and DN50 fire fighting pipes arranged above will damage the DN300 pipes and valves arranged below when earthquakes occur. For the experiments, the relative positions of objects in the room was reproduced by 1: 1. The pressure-holding performance of the pipe was used as a criterion for the damage. The research results of the experiments show that when the 10-meter-long DN50 pipe was dropped from the position of 8 meters height and the 8-meter-long vent dropped from position of 3.6 meters height, they do not affect the integrity of the DN300 valve and pipe below. After the experiment, pressure drop in two hours for the pipe is less than 0.1%. The main body of the valve does not fail neither. The numerical simulation study also shows that there is no failure phenomenon in the simulation as well. Compared with the test results, the impact acceleration and the vent deformation both have the same trend.

Using CFD to Improve the Thermal Characteristic Analysis Methodology of Dry Storage System for Chinshan Nuclear Power Plant

2010 ◽  
Author(s):  
Yung-Shin Tseng ◽  
Jong-Rong Wang ◽  
Chi-Hung Lin ◽  
Chunkuan Shin ◽  
F. Peter Tsai
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Fuel ◽  
Nuclear Power ◽  
Spent Nuclear Fuel ◽  
Storage System ◽  
Thermal Characteristic ◽  
Life Extension ◽  
Fuel Management ◽  
Dry Storage

Chinshan Nuclear Power Plant (CSNPP) is a two-unit BWR4 plant with 1804MWt power per unit. Taipower Co., the owner of the plant is preparing the life extension procedure to extend the CSNPP operation time. In order to meet the life extension requirement, many issues need to be solved before life extension licensing, such as the spent nuclear fuel management, structure aging etc. For the spent nuclear fuel management, ROC Atomic Energy Council (ROCAEC) certified method is employed to analyze the thermal behaviors of Dry Storage System (DSS). This method uses ANSYS coupled with RELAP5-3D to solve the thermal characteristic and successfully accomplish the licensing procedure of the Chinshan Nuclear Dry Storage Project. However, further validation results demonstrate that the coupled method still exists uncertainty and deficiency. In this study, a new Computational Fluid Dynamics (CFD) numerical model for spend nuclear fuel (NSF) dry storage system (DSS) has been developed to improve the accuracy of DSS thermal analysis results. Its accuracy has been validated by comparing the temperature predictions with the experimental results of VSC-17 DSS. It has been found that the thermal behaviors and physical phenomena in the DSS could be predicted with good agreement for the measurements. Moreover, the uncertainty and reasonableness of results in previous method can be improved by the new thermal analyses methodology.

Buried Steel Pipeline Beneath a Surface Impact Close to a Pipe-Structure Interface

2017 ◽  
Author(s):  
Shen Wang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Boundary Effect ◽  
Underground Structure ◽  
Closed Form Solution ◽  
Form Solution ◽  
Life Extension ◽  
Buried Pipeline ◽  
Soil System

For nuclear power plant life extension projects, safety related buried steel pipelines need to be assessed for the effects of postulated accidental impact loads. Examples of such pipelines include emergency firewater lines and control room vent ducts. Published solutions concerning the buried pipeline beneath a surface impact, often aim at a generic problem dealing with a pipe within a half space. The interface between the buried pipes and the underground structure is often ignored. In the case that a buried steel pipe penetrates into nearby underground structure in short distance from a surface impact, shear and bending may originate from reactions at pipe-structure interface, in addition to ovaling and buckling of the pipe section. Neglecting such boundary effect may lead to underestimating potential damage of buried pipeline, and jeopardizing the safety of the nuclear power plant. Comprehensive analysis of such structure-pipe-soil system is often subjected to availability of state-of-art finite element tools, as well as costly and time consuming. This study presents a simplified approach using basic concepts, in order to evaluate the buried pipeline beneath a heavy surface impact considering nearby pipe-structure interface. Applied impulse loadings for postulated surface impact are first established, followed by the evaluation of consequential vertical pressure directly on the top of the pipeline. The pipe cross-section is checked for ovaling and buckling. The closed form solution is then proposed to evaluate effect of pipe-structure interface.

Life Extension of Bolted Flanged Connections From a Design Peculiarities Point of View

2004 ◽  
Author(s):  
Anatoly I. Efremov
Keyword(s):  
Experimental Data ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Point Of View ◽  
Life Extension ◽  
Design Improvement ◽  
Power Plant Equipment ◽  
Bolt Preload ◽  
Plant Equipment

Life extension of Bolted Flanged Connections (BFC) depends directly on early leakage that is a major cause of bolt degradation and failure. Experiments with standard BFC typically used in Nuclear Power Plant equipment and subjected to bolt preload and subsequent internal pressure revealed an influence of the BFC design peculiarities on early leakage. The experimental data became a basis for BFC design improvement.

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