Session: CS-13-01: High Temperature Codes and Standards

Paper Number: 82286

82286 - Extrapolation of High Temperature Material Properties of Inconel 617 for Molten Chloride Reactor Experiment Applications 

The material Inconel 617 was developed in the early 1970’s for high-temperature applications. It is a nickel-chromium-cobalt-molybdenum alloy with a good combination of strength and oxidation resistance properties. Inconel 617 is one of the contenders for the Reactor Enclosure System (RXE) material of the Molten Chloride Reactor Experiment (MCRE) which is at the design stage at TerraPower. The combination of high strength and oxidation resistance properties at high temperatures makes Inconel 617 an attractive material for MCRE applications. However, the properties of Inconel 617 are not available in the high temperature pressure vessel code ASME Section III, Division 5 [1] but are given in Code Case N-898 [2]. With these available properties, a set of design curves were constructed for the RXE of MCRE considering the primary and secondary stresses [3]. For Inconel 617, the maximum temperature is limited because, the high temperature properties (stress to rupture and isochronous stress-strain curves) are available only up to 100,000 hours unlike SS304 and 316 for which properties are available for a time up to 300,000 hours. It can be shown that the creep damage will be 0.1 even for a small value of stress as the maximum creep life would be only 100,000 hours. With a reactor design life of 10,000 hours, the resulting creep damage would be 0.1 (=10,000/100,000). This limits the maximum operating temperature when the design curves were plotted. The purpose of this work is twofold:

 

To identify a methodology to extrapolate the high temperature properties of Inconel 617 up to 300,000 hours. The two properties that need extrapolation are a) time to rupture and b) isochronous stress-strain behavior.

To plot the design curves (for Inconel 617) with the extrapolated properties.

 

The work shows that extrapolation of properties with last two data points looks appropriate compared to Larson-Miller Parameter method [4]. The design curves with the extrapolated properties show that, the maximum temperature can be increased by about 10% compared to design curves without extrapolated data.

 

Reference

 

1.    ASME Boiler and Pressure Vessel Code, Section III, Div. 5 (2017).

2.    ASME Boiler and Pressure Vessel Code, Code Case N-898 (2019).

3.    Design Curves for the Reactor Enclosure System of the Molten Chloride Reactor Experiment, G. Markham, R. Rajasekaran, and R. Christensen, Structural Mechanics in Reactor Technology – SMiRT 26 (2022). Abstract submitted.

4.    Time-Temperature Relationship for Rupture and Creep Stresses, F. R. Larson, and J. Miller. Transactions of ASME (1952).

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Presenting Author: Ramesh Rajasekaran Terrapower, LLC

Presenting Author Biography: Mechanical Integrity Analyst with extensive experience in Design by Analysis using Finite Element Methods and Analytical Procedures. Specialization in Dynamics, Fatigue, Creep and Methods Development of Aeroengine, Gasturbine and Nuclear Reactor components. Developed Corporate Strategies to close the technology gap and written Design Philosophies to layout the analysis processes. Have a Master's degree in Engineering Mechanics and a Doctorate in Engineering Science. Fellow of the Institute of Mechanical Engineers and a Charted Engineer.

Authors:

Ramesh Rajasekaran Terrapower, LLC
Hsu-Kuang Ching Terrapower, LLC
Francesco Deleo Terrapower, LLC