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Toxic Responses of the Lung
Published in Stephen K. Hall, Joana Chakraborty, Randall J. Ruch, Chemical Exposure and Toxic Responses, 2020
Inhalation of any beryllium compound is potentially hazardous. It can produce either acute or chronic beryllium disease. Acute beryllium disease, the acute response to inhaling toxic beryllium compounds, is defined as disease which lasts less than one year, occurs during exposure to beryllium, and includes any of the following: nasopharyngitis, tracheitis, bronchitis, pneumonitis, dermatitis, and conjunctivitis. Ulceration may also be present, and nasal septum perforation can occur. For acute disease, the more soluble beryllium compounds, including beryllium fluoride, beryllium sulfate, and ammonium beryllium fluoride, have been implicated as the cause of both upper and lower respiratory abnormalities. In addition, acute pneumonitis has been associated with beryllium oxide, carbide, oxyfluoride, hydroxide, and zinc beryllium silicate. Chronic beryllium disease is caused by inhalation of the fumes of the metal or an alloy containing beryllium, lasts longer than one year, and usually causes both systemic and pulmonary abnormalities. Skin lesions may develop and the lesions are reddish, papulovesicular, and pruritic. Radiological pattern is non-specific, showing an image that resembles sarcoidosis, tuberculosis, mycosis, or other lung disease. Reactions to beryllium are believed to involve the immune system through formation of an antigen by a beryllium ion combining with a protein or other natural body substance. The term berylliosis should not be used as it implies two false conclusions: (1) beryl ore itself causes disease, and (2) beryllium disease is similar to pneumoconiosis.
Moderator and Reflector Materials
Published in C. K. Gupta, Materials in Nuclear Energy Applications, 1989
For metal extraction there are two major processes that are currently in use. Both use purified BeO as the raw material and convert it into a halide intermediate from which the metal is won. The first of the metal extraction processes involves magnesium reduction of the beryllium fluoride. The starting material, beryllium hydroxide, is converted to ammonium beryllium fluoride by treatment with ammonium bifluoride and/or hydrofluoric acid. Impurities remaining in the beryllium hydroxide, which may include manganese, copper, lead, arsenic, and aluminum, are removed by a series of chemical precipitations, and the purified ammonium beryllium fluoride is subsequently recovered by crystallization. This salt is subsequently heated to about 950°C to give pure anhydrous beryllium fluoride, the ammonium fluoride being returned to the process. The beryllium fluoride is then reduced with magnesium. The reduction is carried out in a graphite-lined furnace, to which magnesium metal and beryllium fluoride are gradually added at a temperature of 900°C. An excess of beryllium fluoride is added for lowering the melting point of the slag and for giving improved metal separation. The beryllium is formed as a fine powder dispersed in a slag of magnesium fluoride-beryllium fluoride. The temperature is raised to coalesce these particles, and the charge is subsequently poured into molds. The beryllium is recovered as small pebbles from the slag matrix. The metal contains an appreciable amount of magnesium and is normally relatively high in metallic impurities.
Toxicology
Published in Martin B., S.Z., of Industrial Hygiene, 2018
Inhalation of any beryllium compound is potentially hazardous. It can produce either acute or chronic beryllium disease. Acute beryllium disease, the acute response to inhaling toxic beryllium compounds, is defined as disease which lasts less than 1 year, occurs during exposure to beryllium, and includes any of the following: nasopharyngitis, tracheitis, bronchitis, pneumonitis, dermatitis, and conjunctivitis. Ulceration may also be present, and nasal septum perforation can occur. For acute disease, the more soluble beryllium compounds, including beryllium fluoride, beryllium sulfate, and ammonium beryllium fluoride, have been implicated as the cause of both upper and lower respiratory abnormalities. In addition, acute pneumonitis has been associated with beryllium oxide, carbide, oxyfluoride, hydroxide, and zinc beryllium silicate. Chronic beryllium disease is caused by inhalation of the fumes of the metal or an alloy containing beryllium, lasts longer than 1 year, and usually causes both systemic and pulmonary abnormalities. Skin lesions may develop and the lesions are reddish, papulovesicular, and pruritic. Radiological pattern is nonspecific, showing an image that resembles sarcoidosis, tuberculosis, mycosis, or other lung disease. Reactions to beryllium are believed to involve the immune system through formation of an antigen by a beryllium ion combining with a protein or other natural body substance. The term berylliosis should not be used as it implies two false conclusions: (1) beryl ore itself causes disease, and (2) beryllium disease is similar to pneumoconiosis.
A Novel Core Design with Movable Moderator for a Fluoride Salt–Cooled High-Temperature Reactor
Published in Nuclear Science and Engineering, 2023
Zuolong Zhu, Dean Wang, Valmor de Almeida, Charles Forsberg, Eugene Shwageraus
ORNL developed a preconceptual design of a 125-MW(thermal) fluoride salt–cooled Small Modular Advanced High-Temperature Reactor4 (Sm-AHTR) and a full-size 3400-MW(thermal) AHTR (Refs. 5 and 6). Both AHTR core designs employ plank-type fuel and FLiBe [lithium-beryllium fluoride (2 7LiF-BeF2)] coolant with 99.95% 7Li. Sm-AHTR was designed to operate for at least 3 years, whereas the AHTR baseline core was sized for a 2-year, single-batch refueling scheme. Investigations for increasing the fuel burnup, multiple fuel batches, and lower fuel enrichments were also performed. A negative reactivity coefficient for the overall average temperature can always persist for these designs, but the moderator temperature coefficient (MTC) still has the potential to become positive.
Heat-Pipe Heat Exchangers for Salt-Cooled Fission and Fusion Reactors to Avoid Salt Freezing and Control Tritium: A Review
Published in Nuclear Technology, 2020
Bahman Zohuri, Stephen Lam, Charles Forsberg
Heat pipes can be designed to be large or small. The maximum heat pipe size will likely be determined by the allowable leakage of sodium into the primary system if there is a leak in the heat pipe. That, in turn, determines the total number of heat pipes required for each application. Sodium is a strong chemical reducing agent that will reduce beryllium fluoride and many other fluorides that may be salt components46 of the coolant salt to metals. Most of these metals have some solubility in the coolant salt. Small additions of sodium to the primary coolant will not have major impacts; but large additions would cause major changes in salt chemistry with different impacts depending upon the type of salt-cooled system. These parameters will place upper limits on individual heat pipe sodium inventories to limit the consequences of leaks. In this context the use of a wick is important because it minimizes the sodium inventory in any individual heat pipe.
Fluoride-Salt-Cooled High-Temperature Reactor (FHR) Using British Advanced Gas-Cooled Reactor (AGR) Refueling Technology and Decay Heat Removal Systems That Prevent Salt Freezing
Published in Nuclear Technology, 2019
Charles Forsberg, Dean Wang, Eugene Shwageraus, Brian Mays, Geoff Parks, Carolyn Coyle, Maolong Liu
Heat pipes can be designed to be large or small. In an FHR the maximum heat pipe size will likely be determined by the allowable leakage of sodium into the primary system if there is a leak in the heat pipe. That, in turn, determines the total number of heat pipes required for the reactor. Sodium is a strong chemical-reducing agent that will reduce beryllium fluoride and many other fluorides that may be salt components31 of the coolant salt to metals. Most of these metals have some solubility in the coolant salt. Small additions of sodium to the primary coolant will not have major impacts, but large additions would cause major changes in salt chemistry and potentially degrade fuel. These parameters will place upper limits on individual heat pipe sodium inventories to limit consequences of leaks. In this context the use of a wick is important, for it minimizes the sodium inventory in any individual heat pipe.