Title: Design, analysis and experimental qualification of gripper bellows for FBTR control rod drive mechanism

Authors: S.C.S.P. Kumar Krovvidi; E. Ramesh; R. Iyappan; A. Kolanjiappan; S. Chandramouli; B.K. Sreedhar; K.V. Suresh Kumar; S. Raghupathy; A.K. Bhaduri

Addresses: Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India ' Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India ' Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India ' Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India ' Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India ' Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India ' Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India ' Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India ' Homi Bhabha Chair Person, Department of Atomic Energy, Kalpakkam 603102, India

Abstract: The design of welded-disc bellows is not addressed in any design codes or standards. This paper discusses the design, analysis and experimental validation of the gripper bellows used in the control rod drive mechanisms of fast breeder test reactor. The material of construction of the bellows is 0.125 mm thick AM350-SCT1000. The design fatigue curve of the material at 803 K is not available in open literature. The fatigue curve of the material (Coffin-Manson's relation) was generated from the tensile testing data using four-point correlation method and universal slopes method. Elasto-plastic finite element analysis of the bellows was carried out and fatigue life of the bellows was estimated numerically. A factor of safety of 20 on number of cycles was used as suggested in codes such as ASME section-III and RCC-MR. Experimental qualification of the bellows as per ASME section-III, appendix-II was carried by testing of the bellows in sodium at 803 K.

Keywords: welded disc bellows; AM350; in-sodium testing; Coffin-Manson plot; four-point correlation; finite element analysis.

DOI: 10.1504/IJNEST.2022.126062

International Journal of Nuclear Energy Science and Technology, 2022 Vol.15 No.3/4, pp.251 - 270

Received: 30 Oct 2021
Accepted: 09 Mar 2022
Published online: 10 Oct 2022 *

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