Protactinium nuclear properties

Table 9.9 lists the isotopes of protactinium important in nuclear technology and some of the important nuclear properties. 

As mentioned, protactinium is one of the rarest elements in existence. Although protactinium was isolated, studied, and identified in 1934, little is known about its chemical and physical properties since only a small amount of the metal was produced. Its major source is the fission by-product of uranium found in the ore pitchblende, and only about 350 milligrams can be extracted from each ton of high-grade uranium ore. Protactinium can also be produced by the submission of samples of throrium-230 (g Th) to radiation in nuclear reactors or particle accelerators, where one proton and one or more neutrons are added to each thorium atom, thus changing element 90 to element 91. 

Third, Pa (protactinium), which occurs in the transmutation chain for the conversion of thorium to acts as a power history dependent neutron poison in a thorium-fueled nuclear reactor. There is no isotope with comparable properties present in a fuel stem. 

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