Nuclear accidents in the past and their reflections in the present

U radu je dana kratka usporedba nuklearnih nesreća u Černobilu i Fukushimi s ciljem planiranja zaštite stanovništva od posljedica moguće nuklearne nesreće u NE PAKS i NE Krško koje se nalaze u blizini Republike Hrvatske. Proučavanje posljedica nesreća u Černobilu i Fukushimi rezultiralo je prikupljanjem znanja i iskustva koja nam mogu pomoći u uklanjanju ili ublažavanju barem dijela neželjenih posljedica ako bi kojim slučajem do toga došlo. Sažimajući iskustva iz ovih nesreća Međunarodna komisija za zaštitu od zračenja ICRP izdala je 2020. godine smjernice za očuvanje zdravlja ljudi i okoliša u sličnim slučajevima. Komisija razlikuje ranu i srednju fazu, koja se smatra hitnim situacijama izloženosti, i dugotrajnu fazu, koja se smatra postojećom situacijom izloženosti. Nadalje preporučuje skup referentnih razina za optimizaciju zaštite stanovništva za sve faze nesreće, a provedba zaštitnih radnji uz radiološke čimbenike mora uzeti u obzir sociopsihološke, ekološke i ekonomske aspekte kako bi se zaštitilo zdravlje i osigurali održivi životni uvjeti. Uzimajući u obzir ove smjernice te nacionalni zakonodavni okvir, Vlada Republike Hrvatske donijela je Plan pripravnosti i odgovora države na izvanredan nuklearni događaj U tom planu detaljno su razrađeni načini postupanja u slučaju najtežih havarija u obje spomenute nuklearne elektrane. Plan detaljno navodi angažman niza tijela državne uprave, lokalne samouprave te ostalih organizacija koje sudjeluju u različitim fazama intervencije i sanacije. Međutim, iskustva iz prethodnih nesreća u Fukushimi i Černobilu ostavljaju otvorenim pitanje efikasnosti provedbe plana u realnoj situaciji.The paper provides a brief comparison of the nuclear accidents in Chernobyl and Fukushima with the aim of planning the protection of the population in case of possible nuclear accident in NE PAKS and NE Krško, which are located near the Republic of Croatia. Studying the consequences of these accidents resulted in the collection of knowledge and experience that can help us eliminate or mitigate some of the unwanted consequences. Summarizing the experiences from these accidents, the International Commission on Radiation Protection ICRP issued guidelines for the preservation of human health and the environment in similar cases. The Commission distinguishes between the early and intermediate phases, which are considered emergency exposure situations, and the long-term phase, which is considered an existing exposure situation. It recommends a set of reference levels to optimize the protection of the population for all phases of an accident. The implementation of protective actions must take into account radiological, socio-psychological, ecological and economic aspects in order to protect health and ensure sustainable living conditions. Taking into account these guidelines and the national legislative framework, the Government of the Republic of Croatia adopted the State Preparedness and Response Plan for an nuclear event. The plan details the engagement of a number of state administration bodies, local governments and other organizations that participate in the various phases of intervention. However, experiences from previous accidents in Fukushima and Chernobyl leave open the question of the effectiveness of the plan’s implementation in a real situation

Isolation of Yttrium and Strontium from Soil Samples and Rapid Determination of 90Sr

A procedure of yttrium and strontium separation from calcium and other cations has been developed for rapid determination of 90Sr in soil samples. The procedure involves yttrium, strontium and other cations bound on cation exchanger AMBERLITE IR-120, separtion of yttrium and strontium from other cations, e.g. potassium, calcium, sodium, barium, on anion exchangers AMBERLITE CG-400 or DOWEX AG 1 × 8 with 0.25 mol l-1 HNO3 in alcohol mixture as eluent, separation of yttrium from strontium on cation exchanger DOWEX 50 × 8 with 3 mol l-1 HNO3, and determination of 90Sr on the low-level gas-flow β-counter and by Cherenkow counting on the liquid-scintillation counter. It has been shown that this procedure might be successfully applied in rapid determination of 90Sr, in a timesaving manner and without application of strong, concentrated acids. The method is appropriate for determination of the water soluble fraction of 90Sr in different kinds of environmental samples (milk, water, wine, vegetables, etc.) with some modification of the sample preparation procedure

New materials for separation of radioactive strontium from the sea water

Otpuštanje 90Sr umora i okeane kao posledica testiranja nuklearnog naouružanja i akcidenata u nuklearnim objektima podstaklo je razvoj novih, jednostavnijih i bržih metoda i materijala za njegovu separaciju. Monitoring morske vode u slučaju akcidentnesituacije, kao i dekontaminacija tečnog otpada koji sadrži morsku vodu, predstavljaju izuzetno zahtevne zadatke usled složenog hemijskog sastava i visokog saliniteta matriksa. U ovom radu dat je pregled najnovijih rezultata u oblasti razvoja materijala sapotencijalom selektivnog vezivanja Sr-jona iz morske vode. Diskutovani su mehanizmi vezivanja i performanse različitih materijala sa aspekta primene u praksi i perspektivnih pravaca budućih istraživanja.The release of 90Sr into the sea and oceans as a result of testing nuclear weapons and accidents in nuclear facilities has prompted the development of new, simpler and faster methods and materials for its separation. The monitoring of seawater in the event of an accident, as well as decontamination of liquid waste containing sea water, represent extremely demanding tasks due to the complex chemical composition and high salinity of the matrix. This paper presents an overview of the latest results in the field of material development with the potential for selective binding of Sr-ions from seawater. Mechanisms of binding and performance of different materials are discussed from the aspect of an application in practice and directions of future research.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Efficient separation of strontium radionuclides from high-salinity wastewater by zeolite 4A synthesized from Bayer process liquids

The efficient, selective, and economical sorbents for the removal of Sr radionuclides are largely needed for the decontamination of effluents with high salinity. In this study, the removal of Sr was investigated using the zeolite produced from the Bayer process liquids. Based on the XRD, SEM/EDS analysis, the product was pure and highly crystalline zeolite 4A (Z4A). Removal of Sr was fast (5 min for 100% removal at 8.80 mg/L), with high maximum sorption capacity (252.5 mg/L), and independent on the initial pH in the range 3.5– 9.0. Specific sorption of Sr by protonated groups on the Z4A surface was operating in addition to ion-exchange with Na ions. The selectivity of Z4A decreased in the order Sr > Ca > K > Mg > Na. 84% of Sr was separated from seawater within 5 min, at the Z4A dose of 5 g/L, while efficiency increased to 99% using the dose of 20 g/L. Desorption of radioisotope 89Sr from seawater/Z4A solid residue was very low in deionized water (0.1–0.2%) and groundwater (0.7%) during 60 days of leaching. Z4A is a cost-effective, selective, and high-capacity medium for Sr removal, which provides high stability of retained radionuclides

Prijenos Cs-137, Sr-90, Ra-226, Pb-210 i K-40 iz tla u biljku u različitim poljoprivrednim kulturama u Hrvatskoj

In this study, we investigated the soil-to-plant transfer of Cs-137, Sr-90, Ra-226, Pb-210 and K-40 in different types of vegetables and fruits collected on family farms in Croatia. The difference in radionuclide distribution between different plant compartments was also investigated. Our results suggest that, in general, the transfer of selected radionuclides within studied soil/plant agricultural ecosystems is on the lower part of ranges reported by IAEA for the temperate environments. Nevertheless, for all studied radionuclides, the transfer to the fruits and vegetables peels was higher than to the pulp. Overall, observed differences in the transfer of radionuclides indicate other additional exposure pathways and mechanisms that affect radionuclide content in plants besides soil activity concentrations.U ovom smo radu istražili prijenos Cs-137, Sr-90, Ra-226, Pb-210 te K-40 iz tla u različite vrste povrća i voća sakupljenih na obiteljskim poljoprivrednim imanjima u Hrvatskoj. Istovremeno su istražene i razlike u prijenosu radionuklida u različite dijelove plodova. Rezultati ovog istraživanja ukazuju da je generalno prijenos radionuklida obuhvaćenih ovom studijom unutar raspona transfer faktora sugeriranih od strane IAEA za umjerena područja, ali na njihovom nižem dijelu. Unatoč nižem transferu, uočen je povišeni prijenos svih istraživanih radionuklida u kore plodova u odnosu na pulpu. Sveukupno, primjećene razlike u prijenosu radionuklida sugeriraju, osim sadržaja radionuklida u tlu, i druge mehanizme i puteve izlaganja radionuklidima, a koje utječu na njihove količine u biljkama.XXXII Simpozijum Društva za zaštitu od zračenja Srbije i Crne Gore, 4-6. oktobar 2023; Budva, Crna GoraProceedings: [https://vinar.vin.bg.ac.rs/handle/123456789/11602

Comparison of some of the analytical techniques and their applications to environmental radiostrontium determination

he knowledge about behavior of 90Sr in environment is of importance to prevent and control contamination. A large number of analytical methods have been developed for the determination of 90Sr in environmental samples. The conducted study was focused on interpretation and evaluation of the results obtained using three radiochemical procedures for the separation of 90Sr and/or 90Y including the classical procedures based on a series of semi-selective precipitations, the ion-exchange procedure and the use of fuming nitric acid. The acquired results showed a good agreement between the compared methods within the terms of accuracy and precision