Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Nukleonika

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

On release of radionuclides from a near-surface radioactive waste repository to the environment

Gudelis A., Gorina I.

Nukleonika

2015

Vol. 60, No. 3, part 2

551--555

A closed near-surface radioactive waste repository is the source of various radionuclides causing the human exposure. Recent investigations confi rm an effectiveness of the engineering barriers installed in 2006 to prevent the penetration of radionuclides to the environment. The tritium activity concentration in groundwater decreased from tens of kBq/l to below hundreds of Bq/l. The monitoring and groundwater level data suggest the leaching of tritium from previously contaminated layers of unsaturated zone by rising groundwater while 210Pb may disperse as a decay product of 226Ra daughters.

Assessment of radionuclide migration and radiological human exposure at the closed near-surface radioactive waste repository

Gudelis A., Nedveckaite T., Prokopčiuk N., Filistovič V., Remeikis V., Motiejunas S.

Nukleonika

2010

Vol. 55, No. 2

251-259

The near-surface “RADON” type radioactive waste repository, installed in 1963 and designed to store radioactive waste formed in industry, medicine and scientific investigations, was closed in 1989 because it did not meet the requirements imposed on the radioactive waste disposal. A comparatively small amount of radioactive waste is stored in this repository, but the inventory comprises various kinds of waste: short-lived low-level radioactive waste, short-lived low and intermediate radioactive waste, long-lived intermediate and high-level radioactive waste. The possible site-specific radionuclide migration through the groundwater pathway as well as the human exposure are considered by the computer program RESRAD-OFFSITE in this paper. The analysis of the obtained data shows that out of all stored radionuclides only H-3, C-14 and Cl-36 exceeding the dose constraint of 0.2 mSv can be considered as dangerous. The monitoring carried out in the repository environment has shown the contamination of groundwater with radioactive tritium and a significant reduction of contamination after construction of additional protective engineering barriers. For the assessment of the contribution of separate site-specific parameters of the model taking into account uncertainties of the model and parameters to the annual effective dose, the computer code RESRAD-OFFSITE provides the possibility of applying the regression analysis. It has been determined that the aquifer lateral dispersion as well as the hydraulic gradient, the radionuclide activity concentration in the repository together with the rate of penetration into the environment and the precipitation amount have the largest influence on the assessment accuracy of annual effective doses.