PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “RADIOACTIVE WASTE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed2001

Environmental impact of radionuclide migration in groundwater from a low-intermediate level radioactive waste repository.

The radionuclide migration from a certain Chinese repository with low-intermediate level radioactive solid waste is studied. The migration in groundwater is analyzed and computed in detail. Under presumption of normal releasing, or the bottom of the repository has been marinated for one month with precipitation reaching 600 mm once and a 6 m aerated zone exists, a prediction for 7 radionuclides is conducted. It shows that the aerated zone is the primary barrier for migration. The migration for radionuclides 60Co, 137Cs, 90Sr, 63Ni, etc. will be retarded in it within 500 years. The concentration of 239Pu will be decreased by amount of 6 order. Only 3H and 14C can migrate through the aerated zone. The radionuclides that go through the aerated zone and enter the aquifer will exist in spring, stream and sea. Based on this, the intake dose by residents in different age group resulting from drinking contaminated spring water, eating seafood is calculated. The results showed that the impact of the repository to the key resident group is lower than the limit in national repository regulation standard. This complies with the repository management target.

Air↗
PubMed2005

Characterisation of radioactive waste products associated with plant decommissioning.

The inventory of radioactivity that must be considered in the decommissioning of a typical 1000 MWe Spanish pressurised water reactor (PWR) was investigated as part of a generic plant decommissioning study. Analyses based on DORT models (in both R-Z and R-theta geometries) were used with representative plant operating history and core power distribution data in defining the expected neutron environment in regions near the reactor core. The activation analyses were performed by multiplying the DORT scalar fluxes by energy-dependent reaction cross sections (based on ENDF/B-VI data) to generate reaction rates on a per atom basis. The results from the ORIGEN2 computer code were also used for determining the activities associated with certain nuclides where multi-group cross section data were not available. In addition to the bulk material activation of equipment and structures near the reactor, the activated corrosion-product (or 'crud') deposits on system and equipment surfaces were considered. The projected activities associated with these sources were primarily based on plant data and experience from operating PWR plants.

Computer Simulation↗
PubMed2003

Cost-Benefit of Final Radiological Survey Versus Radioactive Waste Disposal.

ABSTRACT A significant portion of the cost for D&D is related to low-level waste disposal, decontamination, and final radiological survey. For that reason, a careful cost-benefit analysis must be performed weighing the cost of decontaminating and radiologically surveying the building media for release against the cost of disposing of the material as radioactive waste. This cost-benefit analysis visibly came into play at the Rocky Flats Environmental Technology Site during the recent D&D of two facilities.

Journal Article↗
PubMed2003

Treatment of radioactive wastes: an X-ray absorption spectroscopy study of the reaction of technetium with green rust.

Technetium is a long-lived product of nuclear fission that readily forms the soluble pertechnetate anion [TcO(4)](-). Green rusts (layered hydrous oxides containing both Fe(II) and Fe(III) and with interlayer sulfate or carbonate anions) concentrate >99.8% of 99Tc, present as [TcO(4)](-), from aqueous solution, even in the presence of high concentrations of NaNO(3), a common constituent of radioactive waste streams. The mechanism of removal from solution is apparently reduction and formation of strong Tc(IV) surface complexes. X-ray absorption spectroscopy shows that [TcO(4)](-) is indeed reduced by reaction with both sulfate- and carbonate-form green rusts and is found in a TcO(2)-like environment. On contact with air, the green rusts oxidize to poorly crystalline goethite but the Tc environment is unchanged. There is no increase in Tc solubility associated with oxidation of the host green rust. This behavior suggests that green rusts may be useful in the treatment of Tc-containing waste streams, in groundwater cleanup, and in restricting Tc migration from repositories.

Journal Article↗
PubMedDate not supplied

[Re-establishment of effective radiation dose to personnel of a radioactive waste utilizing plant].

The radiation dose of incorporated cesium-137 was estimated in the workers of a radioactive waste-utilizing plant. For this, methods were developed to retrospectively estimate the dose of internal radiation from the data available in the archives on the body's cesium levels obtained through mass indicator monitoring. The methods were based on the theoretical considerations and variations of inhaled radionuclide intake. The average rhythm of inhalant intake was restored by 891 measurements made in 490 workers to calculate radiation levels in 1977-1995. The individual effective doses of internal radiation of the staff with cesium-137, which were accumulated by 1995 in the persons who began to work at the plant in 1997, were no greater than 1437 muSv and failed to be as high as 1% of the maximum acceptable dose in all cases.

Adult↗