Hydroxylamine Nitrate as a Plutonium Reductant in the Purex Solvent Extraction Process.

Abstract

In laboratory tests, followed by a plant demonstration, hydroxylamine nitrate was shown to be superior to hydroxylamine sulfate for plutonium reduction in the second plutonium cycle of the Purex solvent extraction process. Hydroxylamine nitrate chemical reactions, stability, and rates of plutonium reduction were determined.-2 - CONTENTS

Bistability in the nitric acid‐hydroxylamine CSTR system

“…(5) and eq. (11) that (14) k2 2 5 X lo5 (mol dmP3)-l s-' which conforms to the diffusion controlled limit an the steady state treatment applied. The original version [4,5] of the mechanism of the hydroxylamine-nitric acid reaction postulated NHzOH as the reactive species in (2) rather than NH30H'.…”

Pulse radiolysis study on the reactivity of NO3˙ radical toward uranous(iv), hydrazinium nitrate and hydroxyl ammonium nitrate at room temperature and at 45 °C

“…Due to its Pu(IV) to Pu(III) reducing capacity and scavenging properties of nitrous acid and prevention of backoxidation of Pu(III), hydroxyl ammonium nitrate (HAN) was proposed as a reducing agent in the PUREX process. [24][25][26][27] HAN exists in HNO 3 under its protonated form NH 3 OH + (pKa 1 = 5.96 28 ). However, the destruction of HNO 2 occurs much slower than in the presence of HN, according to reaction (3).…”

γ-ray damage of N,N-diethyl-hydroxylamine in water and its radiolytic products at lower dose

“…(8)], so H 2 volume fraction increases with initial DEHA concentration. On the other hand, the higher the dose, the higher the concentration of HÁ[Eq.…”

“…U (IV)-N 2 H 4 reduces Pu(IV) to Pu(III) very fast, U (IV) is converted to U (VI), which is extracted by the organic stream, the application of U (IV)-N 2 H 4 introduces no nonvolatile or corrosive constituents into the process, but its application has the risk of potential production of explosive HN 3 caused by the reaction of N 2 H 4 with nitrous acid. Mckibben [8] reports that hydroxylamine nitrate (NH 2 OH-HNO 3 ) can quickly and completely reduce Pu(IV) to Pu(III), and in process waste streams, NH 2 OH-HNO 3 can entirely decompose into water and gases at higher temperature, leaving no salt, so it is salt-free reductant.…”