A study on the characteristics of landscape management by area management organization in the core area of large cities

Nowadays, Underground space exploitation is one of the directions of the main focus in the construction of Hangzhou. This paper comprehensively introduces the schematic design of the underground space exploitation of Hangzhou east station, combined with the underground space development project of the core area in Hangzhou eastern new city zone. Firstly, the background of the surrounding area is discussed to illuminate the important status of the core area of eastern new city zone in Hangzhou’s future construction. Then, the holistic design concept and construction goal of the underground space exploitation of the core area are presented, and its functions and layout are clarified focusing on the railway construction and circumjacent exploitation project of Hangzhou east station. Lastly, the executive plan about the underground space exploitation of the core area of Hangzhou eastern new city zone is expatiated comprehensively.

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Reactor Pressure Vessel Integrity Assessment: French Simplified Analysis Method Applied to Underclad Postulated Defect in Nozzle

Volume 7: Operations, Applications and Components ◽

10.1115/pvp2016-63564 ◽

2016 ◽

Author(s):

Adolfo Arrieta-Ruiz ◽

Eric Meister ◽

Stéphane Vidard

Keyword(s):

Fracture Mechanics ◽

Fracture Risk ◽

Pressure Vessel ◽

Reactor Pressure Vessel ◽

Core Area ◽

Integrity Assessment ◽

Elastic Plastic ◽

The Core ◽

Simplified Method ◽

Reactor Pressure

Structural integrity of the Reactor Pressure Vessel (RPV) is one of the main concerns regarding safety and lifetime of Nuclear Power Plants (NPP) since this component is considered as not reasonably replaceable. Fast fracture risk is the main potential damage considered in the integrity assessment of RPV. In France, deterministic integrity assessment for RPV vis-à-vis the brittle fracture risk is based on the crack initiation stage. As regards the core area in particular, the stability of an under-clad postulated flaw is currently evaluated under a Pressurized Thermal Shock (PTS) through a dedicated fracture mechanics simplified method called “beta method”. However, flaw stability analyses are also carried-out in several other areas of the RPV. Thence-forward performing uniform simplified inservice analyses of flaw stability is a major concern for EDF. In this context, 3D finite element elastic-plastic calculations with flaw modelling in the nozzle have been carried out recently and the corresponding results have been compared to those provided by the beta method, codified in the French RSE-M code for under-clad defects in the core area, in the most severe events. The purpose of this work is to validate the employment of the core area fracture mechanics simplified method as a conservative approach for the under-clad postulated flaw stability assessment in the complex geometry of the nozzle. This paper presents both simplified and 3D modelling flaw stability evaluation methods and the corresponding results obtained by running a PTS event. It shows that the employment of the “beta method” provides conservative results in comparison to those produced by elastic-plastic calculations for the cases here studied.

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