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Pile load testing
Published in Harry G. Poulos, Tall Building Foundation Design, 2017
The radioactive source is generally Caesium 137 that emits gamma radiation. The detector is a Geiger–Mueller probe, and the source and detector are placed into different PVC pipes (50 mm diameter) that are cast into the pile in the same way as is done for cross-hole sonic tests. The PVC pipes must be free of any water, and so are sealed to prevent water ingress. The pipes should be inspected to make sure that they are free from water and other obstructions before testing.
Nuclear and Hydropower
Published in Roy L. Nersesian, Energy Economics, 2016
Avogadro’s number 6.02 × 1023 is the number of atoms in a mole of an element where a mole is the atomic weight of an element in grams. For cesium 137 isotope, the atomic weight is 132.9 grams (Website www.webqc.org/molecular-weight-of-Cs137.html). How many atoms is in one gram of cesium 137? Cesium 137 has a half-life of 30.2 years. What would the weight of cesium 137 be after 30.2 years? What would the radiation be in becquerel (one becquerel is defined as one atomic decay per second) over this period? This is average radiation; actual radiation would be higher at the start of the half-life than at the end when there are fewer atoms to decay. Starting with x being the initial radiation and x/2 being end radiation with the derived radiation as the average, what was radiation in becquerel at the start and end of the half-life? From this exercise, one can also see that the shorter the half-life, the higher the radiation. Damage in Sieverts is dependent on both radiation strength in becquerel and the type of radiation.
Advanced Fission Technologies and Systems
Published in William J. Nuttall, Nuclear Renaissance, 2022
Caesium isotopes are a topic of key concern for radioactive waste management. As distinct from the case of technetium, caesium is generated in nuclear fuel use in several isotope forms [153]. The most abundant isotope is caesium-137, which is highly radioactive with a half-life of 30 years [168]. Caesium-137 is a key isotope of concern in severe nuclear accidents. Caesium-135 is more problematic in radioactive waste disposal owing to its longer half-life (2.3 million years). Caesium’s problematic status amongst the LLFP arises partly as a consequence of its susceptibility to biological take-up. This is particularly important given the risks associated with the fact that caesium is readily soluble in groundwater. Groundwater intrusion is a significant consideration in northern European repository locations with granite geology. Other groundwater soluble isotopes include the LLFP iodine-129 and the activation product carbon-14. The conventional European idea for the management of such water-soluble LLFPs is the ‘multi-barrier concept’ of deep geological disposal (see Figure II.5.1). This relies on robust waste containers and repository backfill designed to ensure that the wastes are isolated and dry until long after the soluble LLFPs have safely decayed away to negligible levels. In the UK reprocessing-based fuel cycle, most of the LLFPs form part of the high-level wastes that are vitrified with boron. The sealed stainless-steel flasks containing the vitrified high-level waste are currently surface stored under active management while the radiological hazard is allowed to decay and the self-heating property of the waste diminishes.
Eco-friendly polyvinyl alcohol/beeswax blend prepared using gamma irradiation for adsorption of cesium ions from an aqueous solution
Published in Chemistry and Ecology, 2022
M. I. Aly, M. A. Elhady, E. M. Abu Elgoud, I. M. Mousaa
The common cesium isotope cesium-135 with a half-life time of 2 million years makes it the most effective cesium isotope due to its distribution in the environment. The half-life time of cesium-137 is 30.28 years exists in the (LLRLW) low-level radioactive waste and consider a common fission product (FP) and is known as a beta generator. For the environmental protection from the radiological risk of these radionuclides; the removal of these radionuclides with the well-known separation technique consider of important and highly recommended task [3]. Many chemical separation techniques have been involved in the separation of cesium-137 isotope including flotation, solvent extraction, ion exchange, precipitation, membrane, and ultrafiltration technique [3–9]. The hazardous cesium radionuclides were distributed in the ecosystem coming from nuclear power plants or radioactive labourites sometimes from nuclear accidents [10–15].
Modeling radionuclide transport in urban overland flow: a case study
Published in Urban Water Journal, 2022
Jonathan Shireman, Katherine Ratliff, Anne M. Mikelonis
Radionuclides have been widely dispersed in the environment following nuclear weapons testing and reactor accidents, and Cesium-137 (137Cs) is a particularly persistent contaminant, with a half-life of approximately 30 years. 137Cs poses a risk to human health as a high-energy gamma emitter, and it can quickly spread throughout surface and subsurface environments (Cornell 1993; Evrard et al. 2015). Of recent concern has also been the potential detonation of radiological dispersal devices, or ‘dirty bombs’, and improvised nuclear devices (U.S. Department of Health and Human Services), which could contaminate a wide urban area with 137Cs. Because environmental cleanup efforts can take months to years, precipitation would likely mobilize 137Cs and transport it beyond its initial fallout deposition. Accordingly, modeling tools are useful for predicting the spread of contamination in the environment following a widespread contamination incident, whether it be accidental or manmade.
Reevaluating the Current U.S. Nuclear Regulatory Commission’s Safety Goals
Published in Nuclear Technology, 2021
Vinod Mubayi, Robert Youngblood
The characterization of nuclear power plant societal risk in terms of a large release can be simplified considerably by focusing on the ground contamination caused by the release of the radioactive isotope of cesium, 137Cs, which has a relatively long half-life of about 30 years. The other fission product that could be used to characterize societal risk is iodine, but while it may contribute to radiation exposure of individuals in the short term, the short half-life of its main isotope 131I is around 8 days, so it is not likely to be important in land contamination requiring long-term relocation of the affected population. Hence the proposal to formulate the quantitative objective in terms of the large release frequency metric along the lines proposed in SECY 90-405 consists of specifying a limiting value of Cs release as a fraction of the core inventory that could cause extended (more than 1 year, say) relocation of a substantial number of the offsite public.