Tritium Emissions Research Articles

Technogenic Tritium in Central European Precipitations

An overview of environmental aspects of the tritium method is given. Temporal and local variations of the specific tritium activity of precipitations, particularly the decay of the bomb peak as well as the continential and latitude effects, are used to subdivide the tritium content of precipitations in bomb tritium and technogenic tritium for the example of the measurement series of Freiberg. Technogenic tritium is shown to have prevailed from the beginning of the eighties, whereas the emission of technogenic tritium has strongly decreased in Europe since the middle of the seventies.

Commissioning and First Operating Experience at Darlington Tritium Removal Facility

Ontario Hydro’s Tritium Removal Facility (DTRF) is presently in its early operating phase. The DTRF was built in order to reduce the average dose rate per worker and tritium emissions in all of Ont...

Tritium Emissions Reduction Facility

The Tritium Emissions Reduction Facility (TERF) will be a system for the continuous processing of tritium containing gases collected from various operations at Mound. The basis of the system operation will be the oxidation of elemental hydrogen isotopes and organic molecules at elevated temperatures on precious metal catalyst beds, and the adsorption of the resulting oxide (water) on molecular sieve dryers. The TERF will be expected to handle from 400,000 to 1,000,000 curies of tritium per year in the process gas stream and release no more than 200 curies per year to the atmosphere. Consequently, the TERF will need to convert and capture tritium at low concentrations in gas efficiently and reliably. 5 refs., 2 figs.

A high density of muscarinic receptors in the rostral ventrolateral medulla of the rat is revealed by correction for autoradiographic efficiency

Previous reports of a low density of muscarinic receptors in the vicinity of the rostral ventrolateral reticular nucleus (RVL) conflict with the presence of a muscarinic cholinergic mechanism regulating arterial pressure, and may reflect low autoradiographic efficiency due to quenching of tritium emissions by white matter. Regional autoradiographic efficiency was determined using brains uniformly labeled with O-[ 3 H] methylglucose . Within the RVL, autoradiographic efficiency was only 50 ± 2% relative to gray matter. The uncorrected density of muscarinic receptors (M 2) labeled by [ 3H]quinuclidinyl benzilate in the RVL appeared to be low relative to cranial nerve nuclei, but the corrected muscarinic receptor density approximated that within the nucleus tractus solitarii. We conclude that a high density of M 2 muscarinic acetylcholine receptors is present in the RVL.

Tritium Technology Studies at the Tritium Systems Test Assembly

The Tritium Systems Test Assembly (TSTA) at the Los Alamos National Laboratory has been in operation with tritium since June 1984. Presently there are some 30 g of tritium in the main process loop. This 30 g has been sufficient to do a number of experiments involving the cryogenic distillation isotope separation systems. In January 1986, two major experiments were conducted. During these experiments the fuel cleanup system was interfaced, through the transfer pumping system with the isotope separation system, thus permitting testing on the integrated fuel processing loop. This integration of these systems means that of the TSTA subsystem only the vacuum system remains to be integrated into the TSTA fuel processing loop. In the period of June 1984 through May 1986, the TSTA system had processed approximately 10/sup 8/ Ci of tritium. Total tritium emissions to the environment over this period have been less than 3 Ci as elemental tritium and 2 Ci as tritium oxide. Personnel exposures during this period have totaled less than 100 person-mRem. To date, the development of tritium technology at TSTA has proceeded in progressive and orderly steps. In two years of operation with tritium, no major design flaws have been uncovered.

Regional tritium quenching in quantitative autoradiography of the central nervous system

Direct corrections of regional differential tritium autoabsorption in quantitative autoradiography of the central nervous system are made using chloroform extraction of brain sections from rats receiving tritiated 2-deoxyglucose in vivo. Fifty-two regional quenching coefficients varied from 30% in gray structures to 100% in white structures. These data may be used to correct for regional quenching of tritium emissions in autoradiographic studies of rat brain.

Quantitative receptor autoradiography: tissue defatting eliminates differential self-absorption of tritium radiation in gray and white matter of brain

A four-fold greater absorption (quenching) of tritium emissions by white matter relative to gray matter produces a false ‘contrast’ effect in autoradiographs of 3H-ligand binding to brain sections. The differential absorption is eliminated by tissue defatting prior to autoradiographic exposure.

Tritium experience at RINS-II

Neutrons are produced at the Rotating Target Neutron Source-II (RTNS-II) by deuteron bombardment of a rotating tritium target. Tritium is released from these targets into the accelerator vacuum system. The vacuum system exhaust is first scrubbed and then vented via the facility stack. Tritium emission from the facility in normal operation with vacuum system exhaust flowing through the scrubber is extremely low, <1 mCi/day. Releases from by-passing the tritium scrubber during roughing of the vacuum system and from accelerator maintenance account for nearly all of the annual 10 Ci release from the facility. Routine target changes have been the cause of most tritium uptake by personnel. A target shipping system has been devised for transport of these targets.

Chapter 20 Autoradiographic Analysis of Tritium on Polyacrylamide Gel

Publisher Summary This chapter describes the technique that combines electrophoresis on polyacrylamide gel with autoradiography to analyze small amounts of tritium-labeled RNA. The sensitivity of the technique is increased by working with thin gel slabs dried to a much reduced thickness so as to minimize self absorption of tritium emissions. The use of tritium as a labeling isotope is convenient when dealing with small amounts of material or with low efficiency of incorporation, because of the high specific activity of the 3 H-labeled compounds commercially available. Electrophoresis of RNA is done essentially as described by Loening (1967). Acrylamide and bisacrylamide are used at 2.2 and 0.1% final concentration, respectively. Gel and electrophoresis buffer is 0.02 M sodium acetate, 2 m M sodium EDTA, and 0.04 M tris (pH 7.8); 33 μ l of N, N, N′, N′-tetramethylethylenediamine and 0.33 ml of 10% ammonium persulfate per gram of acrylamide are added. The solution is rapidly mixed and poured into a polymerization chamber, avoiding air bubbles. Polymerization occurs in about 15–20 minutes. The polymerization chamber consists of two microscope glass slides having very regular surfaces. Good separation of RNA fractions is obtained in 30 minutes with a current of 10 m A and a voltage of 100 V, running 10 gels at a time.