Integrity Improvement of High-Temperature Pressure Boundary Components in the Creep Range by Applying Alternative Design Rules

2021 ◽  
Vol 45 (12) ◽  
pp. 1117-1126
Author(s):  
Hyeong-Yeon Lee ◽  
Jewhan Lee ◽  
Jaehyuk Eoh
Keyword(s):  
High Temperature ◽  
Design Rules ◽  
Alternative Design

Design Methodologies for High Temperature Reactor Structural Components Cladded With Noncompliant Materials

2019 ◽  
Author(s):  
B. Barua ◽  
V.-T. Phan ◽  
M. C. Messner ◽  
B. Jetter ◽  
T.-L. Sham ◽  
...  
Keyword(s):  
High Temperature ◽  
Base Material ◽  
Design Rules ◽  
Corrosion Resistant ◽  
Class A ◽  
Creep Fatigue ◽  
The Difference ◽  
Near Term ◽  
Term Creep

Abstract The existing Class A metallic materials qualified for ASME Section III, Division 5 rules for high temperature nuclear reactors, are not optimized for corrosion resistance when exposed to corrosive reactor coolants such as molten salts, and molten lead and lead-bismuth eutectic. Introducing new corrosion-resistant materials into the Code would be a lengthy and expensive process for long design lifetimes, requiring long-term creep test data. A near-term alternative solution might be to allow designers to clad the existing Class A materials with thin layer of some corrosion-resistant material. However, the current ASME Section III, Division 5 rules provide no guidance on evaluating cladded components against the Code creep-fatigue or strain limits requirements. This necessitates the development of design rules for cladded components that do not require long-term testing of clad materials. Depending on the difference in mechanical properties, the influence of clad on the long term response of the structural system can be significant or negligible. This work focuses on developing design rules for cladded components with a clad material that does not accumulate significant inelastic deformation compared to the base material. This work proposes to treat such clad materials as linear elastic. Sample calculations including finite element analyses of a representative molten salt reactor heat exchanger tube without and with clad were performed to verify the proposed approach. Finally, a complete set of design rules for components with noncompliant clad material is proposed.

Comparison of Header Flat End Plate Designs for Operation in the Creep Range

2016 ◽  
Author(s):  
Michael Cooch ◽  
Dave Dewees ◽  
George Komora
Keyword(s):  
High Temperature ◽  
Creep Behavior ◽  
Time Dependent ◽  
Elastic Analysis ◽  
Design Rules ◽  
Expected Time ◽  
Inelastic Analysis ◽  
Weld Area ◽  
High Temperature Operation ◽  
Current Code

Section I of the ASME Boiler and Pressure Vessel Code currently has a Code Case that provides rules for the construction of unstayed flat heads with integral flanges (butt welded hubs) from forged material. This Code Case is currently being considered for adoption into the Section I rules; therefore, the existing requirements of the Code Case are under review. In particular, feedback on the Code Case indicated that the required minimum hub length presents manufacturing challenges in certain situations, so the necessity of this hub is being reviewed. As this type of flat head is commonly used in high temperature operation, evaluation of the expected creep behavior is critical, especially in the proposed weld area at the head junction to the attached shell (typically a header). Example geometries were developed using the current Code Case requirements and their suitability for high temperature operation was initially evaluated using elastic analysis. Detailed inelastic analysis was then performed to further quantify the expected time-dependent high temperature behavior. Additionally, a series of failures of end plates designed to the TRD code was reported to have occurred in Europe in the 1990s. In order to assess the potential relevance of these failures to heads designed per the proposed Section I rules, additional examples were developed using the design rules of the TRD code rules. The predicted creep behavior and damage for these examples were then compared to the Code Case designed examples.

Development of Design Method for High Temperature Nuclear Reactor Cladded Components

2020 ◽  
Author(s):  
B. Barua ◽  
M. C. Messner ◽  
R. I. Jetter ◽  
T.-L. Sham
Keyword(s):  
High Temperature ◽  
Nuclear Reactor ◽  
Nuclear Reactors ◽  
Design Method ◽  
Base Material ◽  
Approximate Design ◽  
Design Rules ◽  
Corrosion Resistant ◽  
Class A

Abstract High temperature nuclear reactors plan to use highly corrosive coolant such as molten salts, molten lead, and lead-bismuth eutectic mixtures. The existing Class A metallic materials qualified in the ASME Section III, Division 5 rules for high temperature nuclear reactors are not ideal for resisting corrosion when exposed to these coolants. One option to overcome this limitation would be to Code-qualify new corrosion-resistant materials for Class A service, however this process is long and expensive and requires long-term creep test data. A near-term alternative would be to allow designers to clad the existing Class A base materials with non-qualified corrosion-resistant materials. However, there are currently no ASME design rules for cladded components to guard against creepfatigue failure and ratcheting strain accumulation in elevated temperature nuclear service. This work addresses this deficiency by proposing a design strategy for cladded components that does not require long-term testing of clad materials. The proposed approach relies on approximate design analysis methods for two types of clad materials — soft clad that creeps faster than the base material and hard clad that creeps slower and has higher yield stress than the base material. The proposed approach treats a soft clad material as perfectly compliant and a hard clad material as linear elastic. Sample finite element analyses of representative high temperature reactor components are performed to verify the approach. At the end, a complete set of design rules is provided for each of the two types of cladded components.

RCC-MRx Edition 2012: Bolt Design Rules Criteria

2014 ◽  
Author(s):  
C. Borazzo ◽  
C. Pétesch ◽  
T. Lebarbé ◽  
O. Ancelet
Keyword(s):  
High Temperature ◽  
Historical Background ◽  
Vacuum Vessel ◽  
Bolted Connections ◽  
Nuclear Facilities ◽  
Design Rules ◽  
Wide Range ◽  
Major Application ◽  
Under Construction ◽  
Connection Design

This paper describes and explains the contents of bolt and bolted connection design rules included in the present 2012 edition of the French RCC-MRx code ([1], applicable to nuclear installation components). The aim of this work is to describe the rules and their technical and historical background, owing to the widespread fields of application in a NPP and to the relative complexity of methods; bolted connections have often a major safety-related role. The domain of the RCC-MRx covers high temperature sodium reactors, experimental nuclear facilities (Jules Horowitz Reactor, research reactor under construction in France), and fusion reactor components (ITER Vacuum Vessel). The first major application is at present for ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration). The bolt connection usual domain varies in a wide range, from very complex configurations, like high temperature, pressure retaining under cyclic load, to simpler flanges for low temperature piping. In order to fulfill such different needs in design, several sets of rules are included at present in RCC-MRx code, issued from the historical development of previous RCC-MR and RCC-MX codes, from which the “RCC-MRx” version is derived. In the following, the existing four configurations of bolted connections are identified, the respective rules are summarized, and, finally, a short comparison with other nuclear codes and industrial standards is provided. Available rules to-date concern respectively: 1) Preloaded bolts assuring leaktightness (type “B1”) 2) Preloaded bolts not assuring leaktightness (“B2”) 3) Non-preloaded bolts (“B3”) 4) Flange bolts

Consideration of Creep in Design Rules of AFCEN RCC-MRx 2012 Code

2013 ◽  
Author(s):  
T. Lebarbé ◽  
C. Petesch ◽  
Y. Lejeail ◽  
P. Lamagnère ◽  
S. Dubiez-Le Goff
Keyword(s):  
High Temperature ◽  
Research Reactor ◽  
Creep Damage ◽  
Vacuum Vessel ◽  
Design Rules ◽  
French And English ◽  
Type Of Exercise ◽  
Set Up

The 2012 edition of the RCC-MRx Code has been issued in French and English versions by AFCEN (Association Française pour les règles de Conception et de Construction des Matériels des Chaudières Electro-nucléaires). This Code is the result of the merger of the RCC-MX 2008 developed in the context of the research reactor Jules Horowitz Reactor project, in the RCC-MR 2007 which set up rules applicable to the design of components operating at high temperature and to the Vacuum Vessel of ITER. This new edition is the opportunity to publish also the background of the rules. This paper is one illustration of what may be such a document, on a dedicated example, the creep rules. It contains an overview of the design rules associated to the creep damage and explains the purpose and the origins of these rules. This type of exercise is going to be generalized to all the parts of the code in AFCEN technical publications, the criteria.

Thermal Design Improvements on Avionic Device in Confined Space under Supersonic Conditions

2013 ◽  
Vol 842 ◽  
pp. 536-540
Author(s):  
Yang Li ◽  
Gui Cui Fu ◽  
Nan Li
Keyword(s):  
High Temperature ◽  
Heat Exchange ◽  
Heat Dissipation ◽  
Thermal Design ◽  
Heat Sinks ◽  
Confined Space ◽  
Design Rules ◽  
Numerical Studies ◽  
Simulation Results ◽  
Electronic Cabinet

Thermal design improvements of avionic devices in confined space under supersonic conditions are presented in this paper through a numerical studies and improvements on the heat sinks and cooling vents. The components locations are also rearranged. Thus the avionic device can operate in the confined space, and heat dissipation can be easier. Simulation results show that the cooling vents added on the surfaces of the electronic cabinet can make heat exchange more smoothly, and the high temperature zones are affected by the changing of the locations of heat sinks obviously. The design rules and guidelines are proposed to improve thermal design. The design and simulation results can be used as the reference for the thermal design of other avionic devices in the similar style.

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