Long-Term Corrosion Behavior of Copper-Base Materials in a Gamma-Irradiated Environment

1986 ◽  
Vol 84 ◽  
Author(s):  
Wlyne H. Yunker ◽  
Robert S. Glass

AbstractThe U. S. Department of Energy is currently evaluating the feasibility of using copper-base materials for the manufacture of nuclear waste con- tainers. One site under consideration for geologic disposal of nuclear waste is at Yucca Mountain, Nevada. One feature of this waste repository will be the initial presence of ionizing gamma radiation at high dose rates, which may alter the corrosive medium. To evaluate such effects, three copper-base materials (pure copper, 7% aluminum-copper and 30% nickel-copper) have been exposed (presgntly up to 14 months) to a gamma radiation field of approxi- mately 1 × 104 roentgens/hr. The exposure environments have been: 1) both groundwater (regional to the repository site, although taken from a lower elevation) at 95°C; 2) the water-vapor saturated air phase above it; and 3) air/water vapor at 150°C. In addition to uniform corrosion, both pitting and crevice corrosion have been observed. Characterization of the corrosion layers by X-ray diffraction has shown the presence of mixed copper(I) and copper(II) oxides. Studies by Auger Electron Spectroscopy (AES) have also been conducted in order to further characterize the compositions and structures of these corrosion products.

1984 ◽  
Vol 44 ◽  
Author(s):  
H Yokoyama ◽  
H-P Hermansson ◽  
H Christensen ◽  
I-K Björner ◽  
L Werme

AbstractTwo types of simulated nuclear waste glasses were leached and simultaneously gamma-irradiated. The leachate pH was reduced through irradiation, which enhanced glass leaching at room temperature. In contrast, the pH was maintained almost neutral in the experiment at 90°C and the leach rates were about five times lower than those for the glass leached at 90°C but out of the radiation field. Most of the leach rates correlated with the final pH of the leachate. Ground water, granite and bentonite moderates the effect of gammairradiation, probably because of a buffering effect. Simultaneous weathering and irradiation could greatly change the surface morphology of the glass.


1987 ◽  
Vol 2 (5) ◽  
pp. 568-579 ◽  
Author(s):  
O. K. Harling ◽  
N. J. Grant ◽  
G. Kohse ◽  
M. Ames ◽  
T-S Lee ◽  
...  

A scoping irradiation test was carried out to help define the performance of copper-base materials in potential fusion applications. Twenty-five different copper materials including oxide dispersion-stabilized and precipitation-hardened powder metallurgy alloys, as well as pure copper and solid solution-strengthened ingot alloys, were neutron irradiated to 13.5 dpa at 400°C in the Experimental Breeder Reactor II (EBR-II) fast reactor. Volumetric swelling and electrical conductivity data were measured for all irradiated materials, and four selected materials were characterized for mechanical property changes using a miniaturized disk bend test. A number of these copper alloys, especially those prepared by powder metallurgy techniques, showed low swelling (less than 0.3%), small changes in conductivity (less than ± 5%), and relatively small changes in yield strength with good post-irradiation ductility. Preliminary electron microscopy results show microstructural changes that are consistent with the results of the macroscopic studies. The pure copper materials showed significant changes in conductivity and high levels of swelling as a result of the neutron exposure. It is apparent that a variety of copper alloys can survive fast neutron exposures to at least 13.5 dpa at 400°C without unacceptable changes in density, conductivity, or yield strength. Further irradiation testing to much higher doses and experimental investigation of the effect of transmutation product gases are needed to fully define the response of available copper alloys to fusion reactor environments.


2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Amal Kamil Abdul Sada ◽  
Amany Mohamed Al-Kaysi

This is an experimental trial to prepare a vaccine from gamma-irradiated Giardia lamblia which is evaluated in experimental animals. The study was conducted from December 2015 to April 2016. The field survey of the parasite was conducted from those patients attending the laboratories of the Alawi Children's Hospital in Rusafa and the Al-Yarmouk Teaching Hospital in Karkh, through which 1250 stool samples of different age groups were examined. Five groups of mice were used in the study; the first was injected with normal saline and considered as a negative control group, the second was injected with cystic form of non-irradiated Giardia lamblia and considered as a positive control group, whereas the other three groups were injected with gamma irradiated Giardia lamblia at three different doses 10, 15 and 25 rad respectively. Giardia lamblia was primarily cultivated in liver infusion agar for ten days to obtain the active phase. On the sixth day, the cystic phase was purified and standardized to be used in the infection of mice with or without the exposure of gamma rays. Mice showed high sensitivity to parasitic infestation, in the gamma non-irradiated and the irradiated with gamma 10 rad, and 15 rad irradiated groups which was 100%. The results expressed an excystation process of the depleted phases and the release of the feeder phases. The results of the three irradiated groups consisted of histopathological changes of the small, and the rectum by dissection after two weeks of infection, with intestine amputation lesions, as well as ulceration and inflammation of the inflammatory cells represented in small numbers of neutrophil, lymphocytes, and eosinophils. The presence of ulceration and fall of epithelial cells in the intestinal cavity has been shown, and different forms of the parasite have been observed. Mice which was injected with irradiated G lamblia at high dose (25 rad), not show and sensitivity to the challenge infection and no excystation of thy parasite had been done. After 2 wreaks, a comparison was achieved between all study groups in which no histopathological changes were noticed in the mice irradiated with dose of25 rad. After another two weeks, a challenge dose was given (un-attenuated G lamblia) and mice were dissected after another two weeks, no changes on the level of histopathology of intestinal tissue were noticed the results suggested that mice acquire an immunity against the parasite infection.


Cureus ◽  
2017 ◽  
Author(s):  
Beza A Dagne ◽  
Melis K Sunay ◽  
Noëlie S Cayla ◽  
Yi-Bing Ouyang ◽  
Susan J Knox ◽  
...  
Keyword(s):  

1983 ◽  
Vol 26 ◽  
Author(s):  
L. D. Tyler ◽  
R. R. Peters ◽  
N. K. Hayden ◽  
J. K. Johnstone ◽  
S. Sinnock

ABSTRACTThe Nevada Nuclear Waste Storage Investigations (NNWSI) project includes a Performance Assessment task to evaluate the containment and isolation potential for a nuclear waste repository at Yucca Mountain in southern Nevada. This task includes calculations of the rates and concentrations at which radionuclides might be released and transported from the repository and will predict their consequences if they enter the human environment. Among the major tasks required for these calculations will be the development of models for water flow and nuclide transport under unsaturated conditions and in fractured hard rock. The program must also quantify the uncertainties associated with the results of the calculations. The performance assessment will provide evaluations needed for making major decisions as the U. S. Department of Energy seeks a site for a repository. An evaluation will be part of the environmental assessments prepared to accompany the potential nomination of the site. If the Yucca mountain site is selected for characterization and development as a repository, the assessments will be required for an environmental impact statement, a safety analysis report, and other documents.This program has been divided into five tasks. Collectively they will provide the performance assessments needed for the NNWSI Project.


2020 ◽  
pp. 200-240
Author(s):  
Rosemary A. Joyce

The concluding chapter explores the visions of the future that experts involved in advising the US Department of Energy developed, as formal parts of their planning documents. These narratives are almost the only place in the planning process where the specific local populations are mentioned. Turning to the question of the people who live in these areas, this chapter explores Native American responses to nuclear waste disposal planning. It contrasts the vision of the US West as an empty space appropriate for waste with indigenous ontologies in which space is full of animate force. The chapter explores the way fiction, narrative, and performances have been cited as possibly better ways to ward off intrusion in dangerous waste sites than any passive system of markers.


2005 ◽  
Vol 68 (12) ◽  
pp. 2571-2579 ◽  
Author(s):  
STÉPHANE CAILLET ◽  
FRANÇOIS SHARECK ◽  
MONIQUE LACROIX

This study was carried out to evaluate the effects of gamma radiation alone or in combination with oregano essential oil on the murein composition of Escherichia coli O157:H7 and on the intracellular and extracellular concentrations of ATP. The bacterial strain was treated with three radiation doses: 0.4 kGy to induce cell damage, 1.1 kGy to obtain a viable but nonculturable state, and 1.3 kGy to cause cell death. Oregano essential oil was used at 0.006 and 0.025% (wt/vol), which is the MIC. All treatments had a significant effect (P ≤ 0.05) on the murein composition, although some muropeptides did not seem to be affected by the treatment. Each treatment had a different effect on the relative percentage and number of muropeptides. There was a significant correlation (P ≤ 0.05) between the decrease in intracellular ATP and the increase in extracellular ATP following treatment of the cells with oregano oil. The reduction of intracellular ATP was even more important when oregano oil was combined with irradiation, but irradiation alone at a high dose (≤1.1 kGy) significantly decreased (P ≤ 0.05) the internal ATP without affecting the external ATP. Transmission electron microscopic examination revealed that oregano oil and irradiation have an effect on cell wall structure.


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