PSI - Issue 71

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 71 (2025) 263–270

5 th International Structural Integrity Conference & Exhibition (SICE 2024)

Tapan K. Sawarn *,a,b , G. M. Nigudage a , Priti Kotak Shah a , Saee Jagtap a Suparna Banerjee a , K. K. Swain c , P. P. Nanekar a,b a Post Irradiation Examination Division, Nuclear Fuels Group, Bhabha Atomic Research Centre, Trombay, Mumbai-400085, India b Homi Bhabha National Institute, Anushaktinagar, Mumbai-400094, India c Analytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085, India Abstract After Fukushima daiichi nuclear accident in March 2011, the post-loss-of-coolant accident (LOCA) fracture resistance of fuel cladding against various loads arising during long term core cooling, fuel handling and storage became a concern in the safety evaluation of reactor core. In this study, the residual bending moment and offset displacement were measured using four point bend tests of fuel cladding which experienced simulated LOCA tests to determine the resistance to fracturing of ballooned burst-oxidised and quenched cladding. The obtained results suggested that the decrease in the maximum bending moment and offset displacement of the cladding were mainly influenced by its microstructure evolved during the testing i.e ductile prior β Zr layer thickness, oxygen and hydrogen in it. It was observed that with increasing ratio of prior β -Zr to oxygen the maximum bending moment and offset displacement increased. Hydrogen played an indirect role on the cladding embrittlement. Due to increasing hydrogen concentration, the oxygen solubility in the prior β -Zr increased causing enhanced embrittlement of the clad at ambient temperature. Mechanical Behavior of PHWR Fuel Cladding Tested Under Simulated LOCA Condition © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers

Keywords: LOCA; PHWR fuel cladding; Bending moment; Oxidation

* Corresponding author. Tel.: +91-22-25595009; fax: +91-22-25505151. E-mail address: sawarn @barc.gov.in

1. Introduction

Nomenclature 4PBT

Four Point Bend Test Alpha plus beta Beta-Zirconium Degree Centigrade

α+β β -Zr

℃

ECCS

Emergency Core Cooling System Distance between loading pins Distance between supporting pins Loss Of Coolant Accident

l 1 l 2

LOCA LWR

Light Water Reactor

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers 10.1016/j.prostr.2025.08.036