PSI - Issue 52

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ScienceDirect Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2023) 000–000 Procedia Structural Integrity 52 (2024) 762–784

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© 2023 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 Professor Ferri Aliabadi Abstract The stress-based assessment described in BS7910:2019 for the demonstration of avoidance of fracture initiation has been applied to a radioactive material transport package. The transport package was designed and manufactured in the early 1990s, predating modern regulatory requirements that are more prescriptive to satisfy the avoidance of brittle fracture. The package design can be usefully re-purposed for the transport of low / intermediate level waste - such as that produced in prototype fission reactors. Current regulations may require demonstration of the avoidance of brittle fracture for this type of package at -40 ◦ C in a fault condition - which, for this package, is considered as an impact from a 1.2m drop height. This paper presents an overview of the demonstration of the package, explaining the process of identifying transient stresses throughout the package and then focusses on treatment of high stresses in the base of the package. Stress classification into primary and secondary stresses is discussed. It is demonstrated that such stresses are permissible by extrapolating from solutions in BS7910:2019 Annex N using cracked body models and taking advantage of low constraint conditions at the crack tip. Keywords: Dynamic fracture, brittle fracture, BS7910:2019, Radioactive material, Transport Package Abstract The stress-based assessment described in BS7910:2019 for the demonstration of avoidance of fracture initiation has been applied to a radioactive material transport package. The transport package was designed and manufactured in the early 1990s, predating modern regulatory requirements that are more prescriptive to satisfy the avoidance of brittle fracture. The package design can be usefully re-purposed for the transport of low / intermediate level waste - such as that produced in prototype fission reactors. Current regulations may require demonstration of the avoidance of brittle fracture for this type of package at -40 ◦ C in a fault condition - which, for this package, is considered as an impact from a 1.2m drop height. This paper presents an overview of the demonstration of the package, explaining the process of identifying transient stresses throughout the package and then focusses on treatment of high stresses in the base of the package. Stress classification into primary and secondary stresses is discussed. It is demonstrated that such stresses are permissible by extrapolating from solutions in BS7910:2019 Annex N using cracked body models and taking advantage of low constraint conditions at the crack tip. Keywords: Dynamic fracture, brittle fracture, BS7910:2019, Radioactive material, Transport Package Nuclear Transport Solutions (NTS) provides international transport services by road, rail and sea for radioactive material during all stages of the fuel cycle. Fission reactors are used globally to produce electricity and play an important future role in baseload energy for the UK and other countries. These reactors generate quantities of spent fuel which, depending on the country of origin, is either stored in fuel ponds or reprocessed. Many countries have yet to develop long term storage solutions for spent fuel and waste. In the UK and France reprocessing has provided a partial solution, improving the sustainability of electricity generation by fission reactors. However, the reprocessing techniques do not recycle 100% of the spent fuel leaving a residual quantity of low, intermediate and high level waste. Structural Integrity Procedia 00 (2023) 000–000 Fracture, Damage and Structural Health Monitoring Demonstration of the avoidance of brittle fracture of a radioactive material transport package during an impact event A.D. Cummings a , C.A. Berry a a Nuclear Transport Solutions (International Nuclear Services Ltd), Hinton House, Birchwood Park Avenue, Warrington, WA3 6GR, United Kingdom www.elsevier.com / locate / procedia Fracture, Damage and Structural Health Monitoring Demonstration of the avoidance of brittle fracture of a radioactive material transport package during an impact event A.D. Cummings a , C.A. Berry a a Nuclear Transport Solutions (International Nuclear Services Ltd), Hinton House, Birchwood Park Avenue, Warrington, WA3 6GR, United Kingdom 1. Introduction Nuclear Transport Solutions (NTS) provides international transport services by road, rail and sea for radioactive material during all stages of the fuel cycle. Fission reactors are used globally to produce electricity and play an important future role in baseload energy for the UK and other countries. These reactors generate quantities of spent fuel which, depending on the country of origin, is either stored in fuel ponds or reprocessed. Many countries have yet to develop long term storage solutions for spent fuel and waste. In the UK and France reprocessing has provided a partial solution, improving the sustainability of electricity generation by fission reactors. However, the reprocessing techniques do not recycle 100% of the spent fuel leaving a residual quantity of low, intermediate and high level waste. ∗ Corresponding author. Tel.: + 44(0)1925 986 338 E-mail address: andrew.cummings@ntsglobal.uk 1. Introduction

∗ Corresponding author. Tel.: + 44(0)1925 986 338 E-mail address: andrew.cummings@ntsglobal.uk

2452-3216 © 2023 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 Professor Ferri Aliabadi 10.1016/j.prostr.2023.12.076