Happy New Year 2024 (and sorry for the forum being offline some hours) /DM
Two major protactinium isotopes, 231Pa and 233Pa, are produced from thorium in nuclear reactors; both are undesirable and are usually removed, thereby adding complexity to the reactor design and operation. In particular, 232Th via (n,2n) reactions produces 231Th which quickly (half-life 25.5 hours) decays to 231Pa. The last isotope, while not a transuranic waste, has a long half-life of 32,760 years and is a major contributor to the long term radiotoxicity of spent nuclear fuel.