Detection of gross beta radioactivity in natural waters by a new evaporation method

Razrađen je veoma jednostavan, precizan, osjetljiv i relativno kratak postupak za određivanje ukupne beta radioaktivnosti u prirodnim vodama. Pokusi su rađeni s uzorcima kišnice. riječnih i cisternskih voda umjet· no kontaminiranim sa smjesom Sr-90, Cs-137 i Ce-144 i na normalnim uzorcima prirodnih voda konlaminiranim radioaktivnim padavinama. Postupak se sastoji u tome da se u uzorak vode od 1 litre doda izvjesna količina otopine kalcijeva acetata i vodena otopina 1 N citronske kiseline, odnosno 1 % otopine kompleksona III, u pari do malog volumena na plinskom kuhalu i kvantitativno prenese u planšete promjera 55 mm. Sadržaj planšeta ispari se do suha i mjeri pomoću protočnog GM brojača niskog osnovnog brojenja, Preciznost metode je vrlo dobra. tako da se standardna relativna greška od mjerenja 10 paralelnih uzoraka kreće unutar greške brojenja. Brojenjem uzoraka kišnice i rijeka od 100 min. i osnovnog brojenja mjernog sistema oko 1.5 imp/min. greška iznosi oko 10%, a kod cisternske vode i manje.A very simple, reproducible and relatively short evaporation procedure for detecting gross beta radioactivity of natural waters has been worked out. The experiments were performed on the samples of rain, river and cystern waters artificially contaminated with 4-year-old fission products and on the samples of natural waters contaminated with the fall-out

A possibility of detecting fresh fission products in the atmosphere by the autoradiographic method

Opisana je mogućnost detekcije svježih fisionih produkata veoma malog intenziteta u atmosferi autoradiografijom sakupljenog aerosola na filtar-papiru. Dati su rezultati autoradiografije i mjerenja opće beta-radioaktivnosti uzoraka zraka iz Zadra te samo opće-beta-radioaktivnosti uzoraka iz Zagreba, Skopja, Gevgelije, Sarajeva, Ljubljane, Ajdovščine i Jezerskog u periodu od 25. VI do 25. VII 1967, tj. u vremenu očekivanog dolaska radioaktivnog oblaka nastalog kao posljedica nuklearne ekspozije u NR Kini 17. VI 1967. godine.Following the June 1967 detonation of a nuclear device over China the autoradiographic technique was used to study the radioactive particulates in surface air samples collected in mass. In the samples collected in the city of Zadar the gross beta-activity per unit volume of air and the number of radioactive parbicles were determined. In the samples collected in the towns of Gevgelija, Sarajevo, Skopje, Ljubljana, Aidovščina, Jezersko and Zagreb only gross beta activity measurements were performed. The sampling was done in the period from June 25 to July 25, 1967

Comparison of three methods for determination of gross beta activity in natural waters

Među sobom su uspoređene tri metode određivanja ukupne beta-radioaktivnosti u prirodnim vodama kontaminiranim radioaktivnim padavinama. Dat je kratak opis i razmatrane su prednosti i mane pojedinih metoda. S obzirom na jednostavnost izvedbe. tačnost, preciznost i mogućnost mjerenja radioaktivnosti, najboljom se pokazala metoda koncentriranja radionuklida na sloju anionske ionsko-izmjenjivačke smole.Two evaporation and an ion-exchange method for determination of gross beta activity in natural waters are compared. The analytical procedure of the three methods is described and the time of analysis as well as the handling of analyzed samples are discussed. Results of analysis of gross beta activity obtained by these methods in naturally contaminated rain, cystern and river waters are given. Simplicity, accuracy and reproducibility of each method are discussed and the method of concentrating radionuclides on a thin ion-exchange resin bed is commended as optimum

Determination of strontium-90 in milk by means of yttrium-90 extraction with tributylphosphate

Opisana je vrlo jednostavna i relativno kratka metoda određivanja stroncija-90 u mlijeku metodom ekstrakcije itrija-90 tributilfosfatom iz slabo dušično kisele otopine pepela mlijeka u koji se doda CaO gotovo do zasićenja. Prikazani su efekti zajedničke ekstrakcije i sutaloženja kalcija i željeza na talogu itrijeva hidroksida. Proučavan je i utjecaj koncentracije fosfata na ekstrakciju itrija tributilfosfatom. Određeni su dekontaminacioni faktori za 144Ce, 106Ru, 95Zr + 95Nb, 137Cs, 85Sr te moguće smetnje 91Y i njegovog uklanjanja pri mjerenju radioaktivnosti 90Y. Dati su rezultati analize umjetno i prirodno kontaminiranih uzoraka mlijeka sa 90Sr.A simple and relatively quick method for the determination of strontium-90 in milk is described. The method is based on the proferential extraction of yttrium-90 with tributylphosphate from a weak nitric acid solution of milk ash to which is added CaO. The effects of calcium, iron and phosphates on the determination of yttrium carrier yield and on the distribution coefficients of yttrium-90 are discussed. The radioactive interferences of Ce144, Ru106, Zr95, Cs137 and Sr65 in the determination of Y90 activity are dealt with. Results of strontium determination in Sr90 spiked milk and in naturally contaminated milk are presented

Applicability and sensitivity of GM - counters for liquids in determination of radionuclides and their mixtures

Opisana je mogućnost upotrebe vrlo brze i jednostavne metode za određivanje ukupne beta-aktivnosti u vodi pomoću GM-brojača za tekućine. Izmjerena je efikasnost brojača za 10 radionuklida s raznim energijama beta-zračenja od 0.44 MeV (Ce-141) do 2.98 MeV (Pr-144), te smjese radiološki najopasnijih fisionih produkata. Zbog svoje jednostavnosti i brzine, metoda je prikladna za mjerenje ukupne beta-aktivnosti u vodi za piće, kao i u drugim vodama u izvanrednim uvjetima većih nuklearnih nesreća ili eksplozije nuklearnog oružja.A very simple and rapid method for determination of gross beta activity in waiter with GM counter for liquids is described. Efficiency of the liquid counter for 10 radionuclides with beta energies ranging from 0.44 MeV (Ce-141) to 2.98 MeV (Pr-144) and for a mixture of the most dangerous fission products has been assessed. Owing to its rapidity and simplicity the method is very suitable for measuring gross beta activity in drinking and other waters in emergency situations

A possibility of detecting fresh fission products in the atmosphere by the autoradiographic method

Opisana je mogućnost detekcije svježih fisionih produkata veoma malog intenziteta u atmosferi autoradiografijom sakupljenog aerosola na filtar-papiru. Dati su rezultati autoradiografije i mjerenja opće beta-radioaktivnosti uzoraka zraka iz Zadra te samo opće-beta-radioaktivnosti uzoraka iz Zagreba, Skopja, Gevgelije, Sarajeva, Ljubljane, Ajdovščine i Jezerskog u periodu od 25. VI do 25. VII 1967, tj. u vremenu očekivanog dolaska radioaktivnog oblaka nastalog kao posljedica nuklearne ekspozije u NR Kini 17. VI 1967. godine.Following the June 1967 detonation of a nuclear device over China the autoradiographic technique was used to study the radioactive particulates in surface air samples collected in mass. In the samples collected in the city of Zadar the gross beta-activity per unit volume of air and the number of radioactive parbicles were determined. In the samples collected in the towns of Gevgelija, Sarajevo, Skopje, Ljubljana, Aidovščina, Jezersko and Zagreb only gross beta activity measurements were performed. The sampling was done in the period from June 25 to July 25, 1967