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Published in Rick Houghton, William Bennett, Emergency Characterization of Unknown Materials, 2020
Rick Houghton, William Bennett
If the unknown substance contains, as its only radioactive source, a pure low-energy beta emitter, the radiation hazard may not be detected by a GM tube. Examples of low-energy beta emitters are hydrogen-3 (tritium), carbon-14, and sulfur-35. These specific sources are difficult if not impossible to detect in a field screen using only a GM tube. These low-energy beta emitters are detectable only by more specialized and sensitive detectors, such as liquid scintillation counting instruments or open window gas proportional detectors. If a radioactive hazard is suspected due to incident circumstance, these low-energy beta hazards should not be neglected. Such equipment may be available from another agency on a case by case basis if only a low-energy beta emitter is suspected. Curie quantities of tritium (a relatively large amount) do not present an external exposure hazard because the low-energy beta emissions cannot penetrate the outer layer of skin. There remains an inhalation and ingestion hazard because tritium is distributed throughout the body as water.
Chemical Monitoring of California's Public Drinking Water Sources: Public Exposures and Health Impacts
Published in Rhoda G.M. Wang, Water Contamination and Health, 2020
Minute traces of radionuclides, isotopic forms of elements that exhibit radioactivity, exist in all drinking water. A large number of natural and artificial radionuclides have been found in water supplies. For groundwater, the nature of the contaminants and their concentration vary regionally depending on the composition of soils and mineral deposits through which the water has moved. Most radioactivity found in drinking water, however, has been the result of a small number of radionuclides. The low linear energy transfer (LET) radionuclides seen in drinking water have included potassium 40 (40K), tritium, (3H), carbon 14 (14C), and rubidium 87 (87R) (13). Tritium, a [}-emitting isotope of hydrogen, is the only low-LET radionuclide of sufficient concern to result in the establishment of an MCL. Natural tritium is produced in the atmosphere as a result of the interactions of cosmic rays with oxygen and nitrogen. When it is oxidized, it forms tritiated water, which after precipitation can contaminate ground and surface water. As a consequence, background tritium concentrations in drinking water range from 10 to 25 pCi/L (13). Tritium, produced and utilized by humans, is of the greatest concern. Tritium is used for research, in self-luminous phosphors, and in nuclear power plants. Because of its short halflife of 12.5 days, the greatest potential threat in the event of an accidental release or improper disposal is to surface water rather than groundwater.
Reactor Coolants, Coolant Pumps, and Power Turbines
Published in Robert E. Masterson, Nuclear Reactor Thermal Hydraulics, 2019
Sometimes the hydrogen atoms in the heavy water molecule are called deuterium atoms. The deuterium atoms in the water molecule are given the chemical symbol D2. In addition to deuterium, ordinary water may also contain some tritium atoms, which contain two neutrons bound to each hydrogen atom instead of just one. (Tritium is an important nuclear fuel in fusion reactors). The chemical symbol for tritium is D3. Sometimes tritium is also given the symbol T3. The chemical symbol for heavy water is D2O.
Tritium Opportunities and Challenges for Fusion Developments Worldwide—CNL and UKAEA View
Published in Fusion Science and Technology, 2023
Stephen Strikwerda, Paul A. Staniec, Monica Jong, Ben Wakeling, Stephen Reynolds, Ian Castillo, Sam Suppiah, Hugh Boniface, Donald Ryland, Todd Whitehorne, Kathrin Abraham, Steve Wheeler, Damian Brennan, Rachel Lawless
Like hydrogen, tritium in elemental form will leak through small cracks and permeate through warm metals. Tritium leaks and permeation, especially into the coolant loops,[23] could result in unacceptable levels of tritium contamination and emissions. Similar issues have been experienced in heavy water reactors and their TRFs,[24,25] but are exacerbated in the fusion DT fuel cycle by higher temperatures and large flows of high-concentration elemental tritium. Using previous studies on tritium emissions and abatement from CANDU reactors and TRFs will be useful to minimize leakage throughout the fuel cycle lifetime. Tritium compatibility guidelines have been developed by various groups, which have measures to reduce tritium leakage. In order to reduce tritium permeation, materials, coatings, and manufacturing techniques are being developed, and permeation through them are being tested with tritium at CNL and UKAEA. These barrier materials will be especially useful for hot, thin-walled applications, such as heat exchangers.
Radiological Characterization Studies for the CNGS Dismantling
Published in Nuclear Science and Engineering, 2023
Claudia Ahdida, Elzbieta Nowak, Christelle Saury, Heinz Vincke, Helmut Vincke
What concerns the marble blocks is the maximum residual dose rate of up to 0.4 mSv/h, which is expected for the collimator located directly downstream from the target and the horn. This material, due to its simple, low-Z chemical composition and resulting low activation, is often used at CERN in high radiation target areas. Marble is composed of calcium, carbon, and oxygen (with atomic fractions 1:1:3). Moreover, only sulfur (0.112%) and manganese (0.024%) impurities were found by in situ XRF measurements on the CNGS marble blocks. The top contributor to the total activity of Bq for the most activated marble collimator is tritium. Its contribution constitutes 98% to the total activity. It should be highlighted that tritium is dangerous only when inhaled or ingested, as it is a pure, low-energy beta emitter with a biological half-life of 10 days.
Application of Pt-Loaded Honeycomb Catalysts in Air Detritiation
Published in Fusion Science and Technology, 2021
Quanwen Wu, Zhenhua Zheng, Jinchun Bao, Wenhua Luo, Daqiao Meng, Zhiyong Huang
Tritium is an important radionuclide in many fields, such as geology, biology, cancer therapy, nuclear fusion fuel, etc. However, its strong migration will cause huge risks to the environment and human body. Therefore, tritium-related operations must strictly implement radiation protection and environmental emission requirements. In accordance with current safety ideas, a triple-confinement system, physical shielding, and detritiation systems (DSs) are necessary to ensure the effectiveness of tritium confinement for tritium facilities.1,2 Currently, large tritium facilities are all equipped with air detritiation systems (ADSs), such as the solid deuterium-tritium (D-T) target chamber of the laser ignition facility at Lawrence Livermore National Laboratory,3 the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory,4 and the Joint European Torus5 (JET). In the International Thermonuclear Experimental Reactor (ITER) under construction, the design of a tritium plant comprises a tokamak fuel cycle processing system as well as tritium confinement and DSs to meet ITER safety guidelines.6