Review of Inaccuracies in the Analysis of the Flow Stability Specific of the LW-SMR Modular Design
Issue:
Volume 8, Issue 1, March 2023
Pages:
1-5
Received:
25 September 2022
Accepted:
9 November 2022
Published:
28 February 2023
Abstract: The presented analysis has been issued to express doubts about the correctness of the engineering and operational safety assessment, which arises from the modeling of transient modes and methodologically should help light water small modular nuclear reactor designers/developers to correct the model they are usually creating for studying the stability of the thermal-hydraulic circuit of the light water small modular nuclear reactor with the natural circulation of primary coolant. After the NuScale report publication and the following presentation review, additional questions arise regarding the analysis methodology, which was carried out and presented as part of the licensing package presented to NRC. After having carefully and critically read the available part of the presented report on the study of instabilities and the presentation issued by NuScale, the answer to the NRC safety committee request could be concluded that the instability analysis has not been performed correctly not only technically, but theoretically. Some clarification of the problem of analysis of instabilities is required additional explanations for further integral light water small modular nuclear reactor design developments and correct analysis implementations.
Abstract: The presented analysis has been issued to express doubts about the correctness of the engineering and operational safety assessment, which arises from the modeling of transient modes and methodologically should help light water small modular nuclear reactor designers/developers to correct the model they are usually creating for studying the stabili...
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Design and Mechanical Characteristics Analysis of Deep Sea Manifold System
Chuxiang Lin,
Weili Wang,
Yongmei Zhu,
Jian Zhang,
Suzhou Zhang,
Longhui Wang
Issue:
Volume 8, Issue 1, March 2023
Pages:
6-13
Received:
6 April 2023
Accepted:
24 April 2023
Published:
10 May 2023
Abstract: Subsea manifolds are important equipment for offshore oil and gas extraction. The layout of the manifold is related to both the difficulty of fabrication and the installation and maintenance of the manifold. Based on 1500 m deep sea conditions and 68.9 MPa pipeline fluid pressure, the overall design of a double well groove and double collector subsea manifold is investigated, the selection of specific parameters is discussed in detail. The arrangement of different valves and pipelines and the efficiency of space volume usage are discussed. Stress analysis of the designed manifold as a whole was carried out using AutoPIPE software and its strength was assessed according to the applicable American Society of Mechanical Engineers (ASME) standards. It was found that the maximum stress ratio was 0.9 for radial stresses and relatively small for axial stresses, but both met the design requirements for deep sea manifold piping. Finally, linear and nonlinear buckling analyses of circular arc pipes were carried out, the fifth-order linear eigenvalue buckling modes, linear critical buckling load and nonlinear critical buckling load were obtained. It is found that the nonlinear critical buckling load was 20.5% lower than the linear critical buckling load. The failure mode of post-buckling is local dimple, which is located at the initial defect, indicating that early geometric defects have a greater influence on the load carrying limit of the pipe. This paper can provide a reference for the study of common technologies for the design of deepwater subsea pipeline manifolds and subsea production facilities.
Abstract: Subsea manifolds are important equipment for offshore oil and gas extraction. The layout of the manifold is related to both the difficulty of fabrication and the installation and maintenance of the manifold. Based on 1500 m deep sea conditions and 68.9 MPa pipeline fluid pressure, the overall design of a double well groove and double collector subs...
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