Session: CS-12-01 High Temperature Codes and Standards

Paper Number: 123510

123510 - A Case Study for a Molten Salt Reactor Design 

The Molten Chloride Reactor Experiment (MCRE) is a design platform for developing and validating TerraPower's Molten Chloride Fast Reactor (MCFR) technology in a critical fast-spectrum molten salt reactor. Within this context, the Reactor Enclosure System (RXE) of the MCRE stands as the primary containment vessel, housing the molten salt fuel and other integral reactor components. Given that reactor components operate in elevated temperatures and consonance with the stringent goals of safety and experimental objectives, the RXE design conforms to the criteria outlined in ASME Section III, Division 5 for Class-A Metallic Pressure Boundary Components. This mandates a comprehensive evaluation of various failure modes, prominently encompassing creep, fatigue, and their interaction. 

In the preliminary stages of design, the exhaustive assessment of creep-fatigue life for each iterative design configuration is impractical, primarily due to this evaluative process's arduous and computationally intensive nature. In response to this challenge, this study introduces a family of curves engineered to expedite the determination of creep-fatigue lives for the RXE across varying parameters. The first set of curves prescribe permissible thickness values, contingent upon through-wall temperature difference and maximum wall temperatures. This set of curves operates under the assumption of constant primary stress without accounting for fluctuations in reactor service life or load cycle counts. 

A second set of curves supplements this work by calculating the RXE's sensitivity to changes in reactor service life and the number of load cycles factored into fatigue damage assessments. Together, these curves furnish a pragmatic sizing methodology for the designers to calculate the effects of incremental design refinements on creep-fatigue life, obviating the need for repetitive detailed evaluations. This paper highlights the methods employed for generating the design curves and offers insights into the outcomes derived from this body of work.

Keywords: MCRE, MCFR, ASME, Design Curves, Creep, Fatigue.

Presenting Author: Ramesh Rajasekaran TerraPower

Presenting Author Biography: Ramesh Rajasekaran currently is a lead principal engineer at TerraPower LLC. He has been working on the creep-fatigue methodologies and analyses used in the high temperature nuclear power plant applications for more than 20 years. He has more than 40 technical papers in this area.

Authors:

Ramesh Rajasekaran TerraPower
Hsu-Kuang Ching TerraPower
David Bankston TerraPower
Francesco Deleo TerraPower