Tension Metastable Fluid Detection Systems for Special Nuclear Material Detection and Monitoring

Abstract

Tension metastable fluid states offer unique potential for radical transformation in radiation detection capabilities. States of tension metastability may be obtained in tailored resonant acoustic systems such as the acoustic tension metastable fluid detector (ATMFD) system or via centrifugal force based systems such as the centrifugal tension metastable fluid detector (CTMFD) system; both under development at Purdue University. Tension metastable fluid detector (TMFD) systems take advantage of the weakened intermolecular bonds of liquids in sub-vacuum states. Nuclear particles incident onto sufficiently tensioned fluids can nucleate critical size vapor bubbles which grow from nanoscales and are then possible to see, hear and record with unprecedented efficiency and capability [1]. Previous work by our group has shown the ability of TMFD systems to detect neutrons with energies spanning eight orders of magnitude with 95%+ intrinsic efficiency [2] while remaining insensitive to gamma photons and also giving directional information [3] on the source of the radiation. In this paper we describe research results with CTMFD systems for use in the detection of key actinide isotopes constituting special nuclear materials (SNMs) in spent fuel. Tests in a CTMFD system demonstrate the ability to detect alpha activity (at ∼100% efficiency) of U-isotopes at concentrations of ∼100 ppb (which is unprecedented and about x100–1000 more sensitive than from conventional liquid scintillation spectroscopy). An inherent capability of TMFD systems concerns on demand tailoring of fluid tension levels allowing for energy discrimination and spectroscopy. This appears especially useful to detect the key isotopes of U and other transuranic isotopes of Pu, Np, Am, and Cm that are at different stages of nuclear fuel reprocessing (i.e. UREX+).