ABSTRACT. We document chemical laboratory procedures and results on international comparison samples at the Hertelendi Laboratory of Environmental Studies, Debrecen, Hungary. We also show results using the new MICADAS system and compare these results to internationally recognized standards and blank materials. The newly developed sample preparation system in HEKAL can handle samples as 1) organic material, 2) cellulose fraction of plant, 3) bones, 4) carbonate and shell, and 5) dissolved inorganic carbon of groundwater. The results of radiocarbon measurements on intercomparison samples confirm the reliability of the sample preparation system at HEKAL Lab and also the good performance of the MICADAS 14 C system. The blank levels for each type of sample of 1 mg C carbon content are well reproducible, ~0.3-0.5 pMC.

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ABSTRACT. We document chemical laboratory procedures and results on international comparison samples at the Hertelendi Laboratory of Environmental Studies, Debrecen, Hungary. We also show results using the new MICADAS system and compare these results to internationally recognized standards and blank materials. The newly developed sample preparation system in HEKAL can handle samples as 1) organic material, 2) cellulose fraction of plant, 3) bones, 4) carbonate and shell, and 5) dissolved inorganic carbon of groundwater. The results of radiocarbon measurements on intercomparison samples confirm the reliability of the sample preparation system at HEKAL Lab and also the good performance of the MICADAS 14 C system. The blank levels for each type of sample of 1 mg C carbon content are well reproducible, ~0.3-0.5 pMC.

The chief objective of this paper is to improve our understanding of the Neolithic in Eastern Hungary using absolute chronological data. To accomplish this we calibrated new measurements as well as previously published dates. The up-to-date, standardized evaluation of 261 calibrated measurements showed temporal overlaps between archaeological cultures defined on the basis of ceramic styles. The increasing number of dates suggest that the Neolithic period began at the turn of the 6th and 7th millennia bc and lasted for ca. 1500 yr in the present area of the Great Hungarian Plain (Alföld). Further research should be aimed at complementing the current data set with dates from western Hungary and establishing additional correlations among stratigraphic, typological and radiocarbon dates.

A more developed and modern technology replaced the old radiocarbon measuring methods in Hungary, based on isotope separation by accelerator mass spectrometry (AMS) and not on activity measurements. In summer 2011, the EnvironMICADAS was successfully installed in the Laboratory of HEKAL, Debrecen, Hungary. In this project, a multipurpose gas-handling system was developed for the gas ion source of EnvironMICADAS at ETH Zürich, designed for the measurement of small environmental origin samples (<50 μg carbon) with moderate precision requirements. The ultimate aim is an automated device for high sample throughput. Since its final installation and first year of operation, over 2000 graphite targets were analyzed. Long-term stability of the instrument is confirmed through measurements of the Ox-II standard and processed blank targets during the first half of 2012.

ABSTRACT. We measured airborne releases of 14C from the Paks Pressurized Water Reactor (PWR) Nuclear Power Plant (NPP).Ttvo continuous stack samplers collect 14C in 14C02 and 14CnHm chemical forms. 14C activities were measured using two techniques; environmental air samples of lower activities were analyzed by proportional counting, stack samples were measured by liquid scintillation counting. 14C concentration of air in the stack varies between 80 and 200 Bqm-3. The average normalized yearly discharge rates for 1988-1993 were 0.74 TBqGW1y1 1y-1 for hydrocarbons and 0.06 TBqGW1y1 1y-1 for CO2.The discharge rate from Paks Nuclear Power Plant is about four times higher than the mean discharge value of a typical Western European PWR NPP. The higher 14C production may be apportioned to the higher level of nitrogen impurities in the primary coolant. Monitoring the long-term average excess from the NPP gave D14C = 3.5%o for CO2 and D14C = 20%o for hydrocarbons. We determined 14C activity concentration in the primary coolant to be ca. 4 kBq liter-1. The 14C activity concentrations of spent mixed bed ion exchange resins vary between 1.2 and 5.3 MBgkg-1 dry weight.

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