scholarly journals Recommendations for the design and construction of base isolated structures

1979 ◽  
Vol 12 (2) ◽  
pp. 136-157
Author(s):  
R. W. G. Blakeiey ◽  
A. W. Charleson ◽  
H. C. Hitchcock ◽  
L. M. Megget ◽  
M. J. N. Priestley ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Base Isolation ◽  
Mechanical Energy ◽  
Future Research ◽  
Design Rules ◽  
Isolated Structures ◽  
Code Provisions ◽  
Design And Construction

The philosophy of base isolation of structures, generally using flexible mountings and mechanical energy dissipating devices, is reviewed. Applications of the approach to buildings, bridges, nuclear power plants, equipment and structures rocking on their foundations are described. Where possible, recommended code provisions and design rules are given. The characteristics of the mechanical energy dissipating devices developed to date are discussed and material specification provisions presented.
 The requirements for construction of base isolated structures and for maintenance of the devices are given. Finally, recommendations are made on matters for future research.

A 12 MM/S RMS Screening Vibration Velocity for Pipes Using ANSI-OM3 Standard and Regulatory Design Rules

2005 ◽  
Author(s):  
Se´bastien Caillaud ◽  
Yannick Pons ◽  
Pierre Moussou ◽  
Michae¨l Gaudin
Keyword(s):  
Correction Factor ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Vibration Monitoring ◽  
Vibration Velocity ◽  
Concentrated Mass ◽  
Design Rules ◽  
Velocity Relationship ◽  
Regulatory Design

ASME ANSI-OM3 standard is dedicated to the assessment of piping vibrations for nuclear power plants. It provides an allowable zero-to-peak velocity, which is derived from a stress/velocity relationship, where corrections factors (C1, C2K2, C3, C4 and C5) and an allowable stress σal are introduced. In the ANSI-OM3 standard, the C4 correction factor depends on the pipe layout and on its boundary conditions, and is calculated for a few cases. In a former work, it was proposed to extend this factor to a larger number of pipe setups. Besides, the correction factor C1, which stands for the effect of concentrated mass, is established on a given set-up: a clamped-clamped straight pipe span on its first vibrating mode. C1 is then supposed to be conservative on any piping layout. Finally, allowable velocities derived from the ANSI-OM3 stress/velocity relationship may be very conservative. One way to reduce this conservatism is to introduce regulatory design rules. For a larger set of pipe geometries, a new set of C1 and C4 correction factors are computed using weight and pressure designs. Using these numerical results, allowable velocities can be calculated. Then, we propose here to check if a screening vibration velocity of 12 mm/s rms is fulfilled. For the 181 geometries on 3708, which do not meet the criterion, a seismic design checking is applied. Finally, by this way, 99.7% of the tested geometries, which are supposed to be acceptable with respect to static and seismic designs, display allowable velocities above 12 mm/s rms and the minimum allowable vibration velocity is 11.2 mm/s. This screening vibration velocity of 12 mm/s commonly used for vibration monitoring of piping systems in EDF nuclear power plants is then supported.

A Critical Comparison of Seismic Qualification Requirements for Safety Equipment in Various Codes and Standards

2003 ◽  
Author(s):  
F. G. Abatt ◽  
Quazi Hossain ◽  
Milon Meyer
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Lower Class ◽  
Department Of Energy ◽  
Building Structures ◽  
Performance Category ◽  
Code Provisions

Evaluation of life safety risks to facility occupants, public, and the environment that may result from earthquake events involves both building structures and equipment supported from these structures. But, it is the seismic design of building structures that typically receive the bulk of the attention from the code committees of the national professional organizations and the regulatory authorities. For safety related equipment in nuclear facilities (e.g., Seismic Category I equipment in nuclear power plants and Seismic Performance Category 3 and 4 equipment in the Department of Energy facilities), the seismic design and analysis guidelines and acceptance criteria are well established. But, for Nonseismic Category equipment in nuclear power plants and Seismic Performance Category 1 and 2 equipment in Department of Energy facilities, these have not yet been developed to the same level of completeness and rigor. The code provisions and guidelines available today for these lower class/categories of equipment are briefly, but critically discussed here, along with a comparison of the results of the application of these code provisions.

Innovative seismic resistant structure of shield building with base isolation and tuned-mass-damping for AP1000 nuclear power plants

2019 ◽  
Vol 36 (4) ◽  
pp. 1238-1257 ◽  
Author(s):  
Gangling Hou ◽  
Meng Li ◽  
Sun Hai ◽  
Tianshu Song ◽  
Lingshu Wu ◽  
...  
Keyword(s):  
Nuclear Power ◽  
High Performance ◽  
Seismic Isolation ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Base Isolation ◽  
Risk Mitigation ◽  
Design Parameters ◽  
Seismic Safety ◽  
Content Type

Purpose Seismic isolation, as an effective risk mitigation strategy of building/bridge structures, is incorporated into AP1000 nuclear power plants (NPPs) to alleviate the seismic damage that may occur to traditional structures of NPPs during their service. This is to promote the passive safety concept in the structural design of AP1000 NPPs against earthquakes. Design/methodology/approach In conjunction with seismic isolation, tuned-mass-damping (TMD) is integrated into the seismic resistance system of AP1000 NPPs to satisfy the multi-functional purposes. The proposed base-isolation-tuned-mass-damper (BIS-TMD) is studied by comparing the seismic performance of NPPs with four different design configurations (i.e. without BIS, BIS, BIS-TMD and TMD) with the design parameters of the TMD subsystem optimized. Findings Such a new seismic protection system (BIS-TMD) is proved to be promising because the advantages of BIS and TMD can be fully used. The benefits of the new structure include effective energy dissipation (i.e. wide vibration absorption band and a stable damping effect), which results in the high performance of NPPs subject to earthquakes with various intensity levels and spectra features. Originality/value Parametric studies are performed to demonstrate the seismic robustness (e.g. consistent performance against the changing mass of the water in the gravity liquid tank and mechanical properties) which further ensures that seismic safety requirements of NPPs can be satisfied through the use of BIS-TMD.

Tellurium radionuclides produced by major accidental events in nuclear power plants

2019 ◽  
Vol 16 (4) ◽  
pp. 296 ◽  
Author(s):  
Teba Gil-Díaz
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Future Research ◽  
Critical Element ◽  
Nuclear Facilities ◽  
Environmental Persistence ◽  
Risk Assessment And Management ◽  
Environmental Compartments

Environmental contextHistorical accidents in nuclear power plants have released radionuclides of several elements, including tellurium, to the environment. Although tellurium radionuclides are significant radioactive emission products, and show medium-term persistence in the environment, the mechanisms behind their widespread dispersion are unknown. Future research into the biogeochemical behaviour of stable tellurium is proposed as an appropriate approach to develop tellurium dispersion scenarios fundamental for post-accident management. AbstractTellurium (Te) is a technology critical element (TCE) and a non-negligible fission product in nuclear facilities. This work compiles the environmental releases of Te radionuclides registered after two nuclear power plant (NPP) major accidental events in human history (Chernobyl and Fukushima Daiichi). Despite the registered non-negligible activities and environmental persistence, Te radionuclides are scarcely monitored, which limits the current understanding of their biogeochemical behaviour, dispersion and fate in all environmental compartments. This lack of knowledge implies an underestimation of the role of Te radionuclides during and after accidents and its consideration in dispersion scenarios, which are fundamental for post-accidental risk assessment and management.

Modularity in nuclear power plants: a review

2016 ◽  
Vol 14 (3) ◽  
pp. 526-542 ◽  
Author(s):  
Ashok Kumar Upadhyay ◽  
Karuna Jain
Keyword(s):  
Literature Review ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Medium Size ◽  
Construction Time ◽  
Content Type ◽  
Emerging Trends ◽  
Comprehensive Classification ◽  
Design And Construction

Purpose Modularity in design and construction of nuclear power plants (NPPs) is widely used for reduction in project construction time and cost. This paper aims to improve understanding of existence, rationale, relevance, types and definitions of modularity in NPPs. Design/methodology/approach The paper approaches study of modularity in NPPs through review of existing literature. The objective of this paper is to answer the questions such as “what is the meaning of module in the context of NPPs?”, “what is the meaning of modularity in the context of NPPs?”, “why modularity is considered in the design and construction of NPPs?”, “what are the types of modules and modularity?” and “what are the emerging trends?” Findings Findings of the paper indicate towards widespread use of modularity to reduce construction time and cost, improve safety performance and enable smarter applications of NPPs. Large NPPs tend to use modularity to shorten the project gestation period, and thereby reduce capital cost. Small and medium size NPPs plan to use modularity for simpler and safer reactors that can be factory manufactured, transported, installed and scaled up as permitted by the economic environment. Research limitations/implications This being a review, it has the usual limitations associated with the literature review papers. Practical implications Findings of the paper may influence policy regarding option, type, size, design, engineering, procurement and construction of NPPs. Social implications Findings of the paper may influence the safety, cost, time and quality performance of future NPPs and facilitate cheaper and more reliable supply of electricity to consumers. Originality/value The systematic literature review presents issues and emerging trends in modularity of NPPs, enabling the future work to progress as modularity continues to develop and evolve. The paper also proposes a comprehensive classification and definitions of modules and modularity in NPPs that may facilitate understanding of these terms precisely and uniformly by researchers and practitioners alike.

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