Radiation chemistry of aqueous iodine systems under nuclear reactor accident conditions

1988 ◽  
Vol 32 (4) ◽  
pp. 593-597 ◽  
Author(s):  
K. Ishigure ◽  
H. Shiraishi ◽  
H. Okuda
Keyword(s):  
Nuclear Reactor ◽  
Radiation Chemistry ◽  
Reactor Accident ◽  
Accident Conditions

The reduction of I2 by H2O2 in aqueous solution

2001 ◽  
Vol 79 (3) ◽  
pp. 304-311 ◽  
Author(s):  
J M Ball ◽  
J B Hnatiw
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Nuclear Reactor ◽  
Ph Dependence ◽  
Radiolysis Product ◽  
Molecular Iodine ◽  
Water Radiolysis ◽  
Reactor Accident ◽  
Rate Law ◽  
Accident Conditions

The reduction of I2 by hydrogen peroxide, a primary water radiolysis product, has been identified as a key reaction that would influence iodine volatility in nuclear reactor accident conditions (1–3). Although there have been a number of studies of the reduction of I2, there exists a great degree of controversy regarding the intermediates involved, the effect of buffers, and the general rate law (1–9). Because the rates and the mechanism of this reaction are important in predicting the pH dependence of iodine behaviour in reactor containment building after a postulated reactor accident, we have undertaken a kinetic study of I2 reduction by H2O2 in aqueous solution over a pH range of 6–9. The experiments were performed using stopped-flow instrumentation and monitoring the decay of I–3 spectrophotometrically. The effects of buffer catalysis have been examined by comparison of kinetic data obtained in sodium barbital (5,5-diethylbarbituric acid), disodium citrate, and disodium hydrogen phosphate buffers. The effect of buffers, combined with the complex acid dependence of the rate law, explains many of the discrepancies reported in earlier literature.Key words: hydrogen peroxide, molecular iodine, kinetics, iodine volatility.

Eds Of Radioactive Particles By Self-Induced Fluorescence

1990 ◽  
Vol 48 (2) ◽  
pp. 238-239
Author(s):  
Gregory L. Finch ◽  
Richard G. Cuddihy
Keyword(s):  
Electron Beam Irradiation ◽  
Nuclear Reactor ◽  
X Rays ◽  
Reactor Accident ◽  
Internal Radiation ◽  
X Ray ◽  
External Sources ◽  
X Irradiation ◽  
Available Information ◽  
Individual Particles

The elemental composition of individual particles is commonly measured by using energydispersive spectroscopic microanalysis (EDS) of samples excited with electron beam irradiation. Similarly, several investigators have characterized particles by using external monochromatic X-irradiation rather than electrons. However, there is little available information describing measurements of particulate characteristic X rays produced not from external sources of radiation, but rather from internal radiation contained within the particle itself. Here, we describe the low-energy (< 20 KeV) characteristic X-ray spectra produced by internal radiation self-excitation of two general types of particulate samples; individual radioactive particles produced during the Chernobyl nuclear reactor accident and radioactive fused aluminosilicate particles (FAP). In addition, we compare these spectra with those generated by conventional EDS.Approximately thirty radioactive particle samples from the Chernobyl accident were on a sample of wood that was near the reactor when the accident occurred. Individual particles still on the wood were microdissected from the bulk matrix after bulk autoradiography.

Nuclear Power Plant Fires and Explosions: Part IV — Water Hammer Explosion Mechanisms

2017 ◽  
Author(s):  
Robert A. Leishear
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Reactor ◽  
Water Hammer ◽  
Compression Process ◽  
Flammable Gas ◽  
Piping Systems ◽  
Fukushima Daiichi ◽  
Accident Conditions

Water hammers, or fluid transients, compress flammable gasses to their autognition temperatures in piping systems to cause fires or explosions. While this statement may be true for many industrial systems, the focus of this research are reactor coolant water systems (RCW) in nuclear power plants, which generate flammable gasses during normal operations and during accident conditions, such as loss of coolant accidents (LOCA’s) or reactor meltdowns. When combustion occurs, the gas will either burn (deflagrate) or explode, depending on the system geometry and the quantity of the flammable gas and oxygen. If there is sufficient oxygen inside the pipe during the compression process, an explosion can ignite immediately. If there is insufficient oxygen to initiate combustion inside the pipe, the flammable gas can only ignite if released to air, an oxygen rich environment. This presentation considers the fundamentals of gas compression and causes of ignition in nuclear reactor systems. In addition to these ignition mechanisms, specific applications are briefly considered. Those applications include a hydrogen fire following the Three Mile Island meltdown, hydrogen explosions following Fukushima Daiichi explosions, and on-going fires and explosions in U.S nuclear power plants. Novel conclusions are presented here as follows. 1. A hydrogen fire was ignited by water hammer at Three Mile Island. 2. Hydrogen explosions were ignited by water hammer at Fukushima Daiichi. 3. Piping damages in U.S. commercial nuclear reactor systems have occurred since reactors were first built. These damages were not caused by water hammer alone, but were caused by water hammer compression of flammable hydrogen and resultant deflagration or detonation inside of the piping.

Knowledge on radiation emergency preparedness among nuclear medicine technologists

2021 ◽  
Author(s):  
N.A. Shubayr ◽  
Y.I. Alashban
Keyword(s):  
Nuclear Medicine ◽  
Emergency Preparedness ◽  
Nuclear Reactor ◽  
Radiation Detection ◽  
Population Monitoring ◽  
Geiger Counter ◽  
Willingness To Participate ◽  
Reactor Accident ◽  
Radiation Emergency ◽  
Emergency Preparedness And Response

This study aimed to assess the knowledge of nuclear medicine technologists (NMTs) in radiation emergency preparedness and response operations and their willingness to participate in such operations. A survey was developed for this purpose and distributed to NMTs in Saudi Arabia. Sixty participants responded with a response rate of 63.31%. Based on the overall radiation protection knowledge related to emergency response, NMTs can perform radiation detection, population monitoring, patient decontamination, and assist with radiological dose assessments during radiation emergencies. There were no significant differences in the knowledge on the use of scintillation gamma camera (P = 0.314), well counter (P = 0.744), Geiger counter (P = 0.935), thyroid probes (P = 0.980), portable monitor (P = 0.830), or portable multichannel analyzer (P = 0.413) and years of experience. Approximately 44% of the respondents reported receiving emergency preparedness training in the last 5 years. Respondents who reported receiving training were significantly more familiar with the emergency preparedness resources (P = 0.031) and more willing to assist with radiation detection or monitoring in the event of nuclear reactor accident (P = 0.016), nuclear weapon detonation (P = 0.002), and dirty bomb detonation (P = 0.003). These findings indicate the importance of training and continuing education in radiological emergency preparedness and response, which increase the willingness to respond to radiological accidents and fill the gaps in NMTs’ knowledge and familiarity with response resources.

Swedish Nuclear Power and Economic Rationalities

2002 ◽  
Vol 13 (2) ◽  
pp. 191-206 ◽  
Author(s):  
Tomas Kåberger
Keyword(s):  
Nuclear Power ◽  
Nuclear Reactor ◽  
Electricity Production ◽  
Carbon Taxes ◽  
Long Term Effects ◽  
Reactor Accident ◽  
Energy Supply System ◽  
High Investment ◽  
Market Evaluation ◽  
The Cost

The economic characteristics of nuclear power, with high investment cost and fuel costs lower than conventional fuels, make it possible to achieve low electricity prices when reactors supply marginal electricity. The support for nuclear power by the Swedish electricity consuming industry may be understood as efforts to create and defend a situation of over-capacity in the electricity production sector rather than as support for nuclear power as such. Politically the external costs of routine emissions of radioactive materials are difficult to internalise because they, like carbon dioxide, have global long-term effects. However, like the air pollutants already regulated, costs of reactor accidents, as well as the motives for taking on management costs of nuclear waste, are regional and within a generation in time. The market evaluation of accident risks has been deliberately destroyed by legislation set to favour nuclear power reactors. Societal economic rationality may be successfully applied in the energy sector. This paper describes how climate change risks were internalised in Sweden using carbon taxes under favourable political conditions. The resulting development of biofuels was surprisingly successful, indicating a potential for further modernisation of the energy supply system. Possible ways to restore the nuclear risk market in order to internalise nuclear reactor accident risks and waste costs by legislation are described. This may be done without the difficult quantification of environmental costs. Appropriate legislation may internalise the cost while creating conditions for market evaluation of these uncertain costs.

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