A protocol for the radiological assessment for agricultural use of land in Ukraine abandoned after the Chornobyl accident.

There is a need in Ukraine for re-evaluation of the status of lands outside the Chornobyl Exclusion Zone which were abandoned in the years after the accident. Since the 1991 criteria for zoning were put in place, there has been no re-classification of abandoned lands even though radionuclide contamination density and, for radiocaesium isotopes, mobility have both declined. This study describes the development of a protocol for assessment of abandoned lands in Ukraine based on a 100 ha experimental plot.

Natural attenuation processes control groundwater contamination in the Chernobyl exclusion zone: evidence from 35 years of radiological monitoring.

The Chernobyl Exclusion Zone (CEZ) contains the vast majority of radionuclides released by the accident in nuclear fuel particle form. We present and analyze groundwater measurements collected from the monitoring network in CEZ covering key aquifers over 35 years since the accident. These new data, together with a comprehensive analysis of historical data shows that Sr remains mobile in the subsurface environment, while groundwater concentrations of Cs, Pu isotopes and Am are relatively low, and are not of radiological concern.

Simulating dissolved Sr concentrations within a small catchment in the Chernobyl Exclusion Zone using a parametric hydrochemical model.

Strontium-90 (Sr) is the major long-lived radionuclide derived from the Chernobyl accident, and is still being detected in the heavily contaminated catchments of the Chernobyl Exclusion Zone. This study examines the long-term decrease in the dissolved-phase Sr concentration and the concentration-discharge (Sr-Q) relationship in stream water since the accident. We show that the slow decline in Sr follows a double-exponential function, and that there is a clear relationship between Sr and Q.

Solid-liquid distribution coefficients (Kd-s) of geological deposits at the Chernobyl Nuclear Power Plant site with respect to Sr, Cs and Pu radionuclides: A short review.

A review is presented of data on solid-liquid distribution coefficients (Kd-s) of the main radiologically important radionuclides of the Chernobyl release within geological deposits at the Chernobyl Nuclear Power Plant (ChNPP) Site. The Kd values for Sr, Cs and Pu for Quaternary sandy deposits that form sedimentary cover at Chernobyl fall within the range of parameters reported in international sorption databases. In agreement with general knowledge on radionuclide geochemical behavior and affinity to soils, Kd-s increase in the sequence: Sr < Cs < Pu.

High (36)Cl/Cl ratios in Chernobyl groundwater.

After the explosion of the Chernobyl Nuclear Power Plant in April 1986, contaminated material was buried in shallow trenches within the exclusion zone. A (90)Sr plume was evidenced downgradient of one of these trenches, trench T22. Due to its conservative properties, (36)Cl is investigated here as a potential tracer to determine the maximal extent of the contamination plume from the trench in groundwater.