High Resolution Neutron-induced Autoradiography of Bone Containing 239Pu

Abstract

The detailed neutron-induced autoradiographic process for bone containing zasPu produces autoradiographs with both fission fragment tracks and a corresponding bone image. Seven-microns-thick undecalcified bone sections were affixed on 300-pm-thick Lexan (polycarbonate) film coated with 0.5 % calf skin gelatin and exposed to neutrons in the thermal column of the Material Testing Reactor (MTR) at the National Reactor Testing Station in Idaho. The specimens were immersed in 28% KOH at 5OoC for 1-14 hr to etch pinholes at the location of each fission track and to pit the film at the location of the bone. When the films were etched immediately after irradiation, no bone image was produced, but when the bone sections were allowed to remain on the film for several weeks after irradiation, the irradiated bone caused a pitting of the film surface. Betas from 32P seemed to be the main charged particles available to produce the pitting. This detailed neutron-induced autoradiographic process has advantages over the nuclear emulsion autoradiography of bones because it eliminates long exposure times and fading of latent image. It is a rapid, effective procedure.

Quantitative Plutonium Microdistribution in Bone Tissue of Vertebra From a Mayak Worker

“…Rather than waiting for a natural decay of the isotope with the registration of the alpha emission on a photographic film or emulsion, NIAR accelerates this by exposing the sections to thermal neutrons that will cause the 239 Pu to fission. The fission fragments are registered on plastic detectors, rather than a photographic film or emulsion, as previously described in greater detail (Jee et al 1972; Bruenger et al 1991). In addition, use of the NIAR is very practical to study plutonium distribution in bone tissue inasmuch as decalcification is not necessary.…”

“…These include structural bone elements and tissue compartments, (i.e. endosteal surfaces, bone tissue, bone marrow) (Wronski et al 1980; Jee et al 1972). …”

A new method for the accurate localization of 239Pu in bone

“…I n this paper we report a new analytical technique for determining the distribution of 239Pu with respect t o bone surfaces with an accuracy of about -1: 2 pm. Neutron induced autoradiography of bone sections was used to give a high contrast bone image, together with tracks from neutron induced fission of the 239Pu (Jee, Dell and Miller 1972). These neutron induced autoradiographs have been analysed using semi-automatic digitization of the bone edges and track ends together with deconvolution analysis of the resultant track distributions.…”