DEPOSITION OF PLUTONIUM NITRATE COMPLEXES FROM AQUEOUS LIQUID ONTO A STAINLESS-STEEL SURFACE

Qualitative calculations are reported for the theoretical equilibrium deposition level of six nitrate complexes of plutonium (IV) from aqueo us liquid onto a stainless steel surface oxide layer. It was found tha t the major contributors to deposition are the hexanitrato and pentani trato complexes, which exist and adsorb prominently at high fluid acid ity (pH 0-2), and the trinitrato complex at around pH 7. To minimize d eposition it is shown that a fluid pH between 2 and 6 was desirable an d that a pH below 2 should, in particular, be avoided. A higher operat ing temperature was also found to reduce deposition.