A method for the determination of short-lived activation products in neutron-irradiated sodium is described. It is based on hydrolysis of sodium with methanol, separation of Na+ with specially prepared antimony pentoxide (HAP) possessing very high selectivity and capacity, and subsequent gamma-spectroscopic measurement of the activation products.
Compton suppression spectrometry was used to analyze foods for elements with short-lived neutron activation products (half-lives
of about 2 minutes to 1.5 days). Analysis conditions were optimized to provide quality assurance analyses for iodine in FDA’s
Total Diet Study. Iodine mass fractions (0.075 to 2.03 mg/kg) were measured in 19 of 42 foods analyzed, with limits of detection
(LODs) ranging from 0.03 to 1.4 mg/kg, mostly depending on NaCl content. LODs were lowered by up to a factor of 2 for 16 elements.
Suppression factors ranged from about 2 to 8 over the energy range 400 to 3200 keV.
The carrier-free radiotracers,52,56Mn,55,56,58Co and56,57Ni were produced simultaneously by accelerated -particle activation of iron. They were subsequently studied through LLX using the liquid cation exchanger, HDEHP, as an extractant. A considerable enrichment of individual carrier free radionuclides of manganese, cobalt and nickel was achieved. Production and verification of purity of the carrier-free radiotracers at different stages of their extraction were carried out by -ray spectroscopic studies.
A radiochemical charged particle activation procedure has been developed for the production and separation of the carrier free radioisotopes,65Zn and66,67,68Ga. The carrier free radioisotopes produced by the irradiation of a pure copper foil with 50 MeV -particle beam through the nuclear reactions, (, pxn), (,pxn) and (,xn), have been quantitatively separated from the activated copper matrix from an aqueous hydrochloric acid and an alkaline solution using the liquid cation exchanger HDEHP, as an extractant. Detection of different radionuclides in the activated copper target and verification of their purity at different stages of their LLX separation have been performed by -ray spectrometric studies.
Neutron activation analysis utilizing the High Flux Isotope Reactor (HFIR) immediately following SCRAM is a workable solution
to obtaining data for ultra-short lived species, principally Al, Ti, Mg, and V. Neutrons are produced in the HFIR core within
the beryllium reflector due to gamma-ray bombardment from the spent fuel element. This neutron flux is not constant, varying
by over two orders of magnitude during the first 24 hours. The problems associated with irradiation in a changing neutron
flux are removed through the use of a specially tailored activation equation. This activation equation is applicable to any
irradiation at HFIR in the first 24 hours after SCRAM since the fuel elements are identical from cycle to cycle, and the gamma-emitting
nuclides responsible for the neutrons reach saturation during the fuel cycle. Reference material tests demonstrate that this
method is successful, and detection limit estimates reveal that it should be applicable to materials of widely ranging mass
Authors:N. Jordan, H. Michel, G. Barci-Funel, and V. Barci
Nickel-63 is a low energy beta-emitter needing a radiochemical separation before β-counting. Several papers described the
separation and the detection of 63Ni in environmental samples. The method used in our work was first developed by Skwarzec and Holm. The main steps of this separation are the selective precipitation of nickel with dimethylglyoxime (DMG) and the use of the
non-sorption of nickel on anion resin in hydrochloric acid solutions. In this paper, a new step is added to eliminate high
quantities of calcium and magnesium phosphate disturbing the iron hydroxide precipitation step. The procedure has been applied
to soft water samples: sediments, plants and fishes. The chemical yields are 60, 70 and 20%, respectively. The detection limit
of 63Ni by liquid scintillation spectrometer is 10 mBq.
Authors:M. Galamboš, P. Suchánek, and O. Rosskopfová
The history of sorption and ion-exchange processes starts with the use of natural materials which properties were discovered
coincidentally and ends with the age of polymer and anorganic—or synthetic sorbents specifically made for a particular project.
Its objectives are focused on sorption of anthropogenic radionuclides originating from nuclear power plant operations (fission,
activation, corrosion products and transuranium elements) on bentonites, zeolites, hydroxyapatites, magnetic sorbent, ferrocyanides,
and silica sorbent. Bentonites from Slovak deposits should be used as part of multi-barrier system in deep geological repository
for spent nuclear fuel and high level radioactive waste. Zeolites are used as molecular sieves, catalysts, ion-exchangers,
sorbents, water softeners, in wastewater treatment, in chemistry industry, buildings. Hydroxyapatite is a suitable sorbent
for heavy metals and radionuclides due to its low water solubility, high stability under reducing and oxidizing conditions,
high specific surface area and good buffering properties. The leaching wastes from the Sereď hydrometallurgical plant represent
a large stock of inexpensive, ready-to-use magnetic sorbent for the decontamination of soil or sediments in their common suspensions,
followed by the magnetic separation and sorbent recycling. Insoluble ferrocyanides of nickel are highly selective sorbents
for heavy alkali metals ions, and therefore can be used to separate cesium from liquid radioactve waste. Silica sorbents modified
with imidazole can be used for the separation of cobalt ions from aqueous solution.
Authors:P. Bachelor, J. Friese, C. Aalseth, J. McIntyre, H. Miley, R. Perkins, and G. Warren
In anticipation of a nuclear detonation, techniques to quickly assess the radiation exposure of evacuees should be developed.
Based on experience relating neutron radiation exposures to activation products, measurement of activation products can be
performed in a few minutes. Personal items exposed to significant levels of radiation allows neutron dose assessment via the
activation products. This approach allows prompt collection of important data on human exposure following a nuclear attack.
Data collected will facilitate triage decisions for emergency medical treatment to ameliorate the radiation effects on exposed
individuals. Activation experiments with everyday items exposed to a neutron source are presented.
A simple and rapid method was developed for the determination of selenium in human serum using a pre-irradiation separation technique of ultrafiltration followed by neutron activation analysis via the short-lived activation product77mSe. The method was validated using certified reference material.
Neutron activation analysis of rare-earth elements in silicate rocks containing several parts per million uranium may be complicated
by interference from235U fission products and activation products of238U. The degree of interference has been measured quatitatively for La, Ce, Nd, Sm and Lu, and a method of correcting the NAA
data for these elements is presented.