Richárd Kardos, 1 Borbála Máté, 1 Mária Horváth, 2 Anita Csordás, 1 Tibor Kovács

Transcription

1 1 Richárd Kardos, 1 Borbála Máté, 1 Mária Horváth, 2 Anita Csordás, 1 Tibor Kovács 1 III. Terrestrial Radionuclides in Environment International Conference on Environmental Protection Veszprém, May 16-18,

2 Structure of the presentation Introduction Sampling sites Sampling Determination of uranium isotopes Results Conclusion

3 Introduction Three type of area has been selected Spring water (Budapest) Industrial area (radioactive waste storage, Bátaapáti) Contaminated, disaster-affected surface water (Torna stream)

4 Térkép

5 Sampling sites I. Budapest Samples from the Buda Hills area Samples were taken from street wells (drinking waters) On this area the 226 Ra concentration of the rock is high

6 Sampling sites II. Bátaapáti Low and intermediate level radioactive waste storage 2 tunnel were created 37 km from Paks (Nuclear Power Plant) Hard granite stone Groundwaters and surface waters were measured

7 Sampling sites III. Torna stream Hilly stream Torna Marcal Rába river Moson-Danube Danube 5 th October 2010 red mud disaster of the alumina The dam damaged The wildlife of the stream extinct

8

9

10

11 Sampling I. Bátaapáti 10 th February 2010 Samples were collected from 6 places (5 L) Operating area, 2 samples from Mária pit (Ba-1) From near the storage, 2 samples, beginning of the stream (Ba-2) From the stream, 4 points (Ba-3 - Ba-6)

12 Sampling II. Budapest 9 th September th March L 25-29, Frankel Leó street (Bp-1) 11, Állatkerti boulevard (Bp-2) 9, Döbrentei street (Bp-3) 3, Pusztakúti street (Bp-4) Margaret Island (Bp-5) Street wells (drinking waters)

13 Sampling III. Torna stream The effluent red mud contaminated the stream directly 6 sampling were done from the first day of the disaster (5 L, 1 day/1 sample) The second round of samples was taken in different points of the stream, Somlójenő, Városlőd, next to the storage (21 th March 2011)

14 Determination of 234 U, 238 U The sources were made from 0.5 L samples Used tracer: 232 U Sample preparation Filtration ph setting Fe(OH) 3 precipitation Filtration, resolution of precipitation Separation of U (UTEVA resin) Source preparation by electrodeposition Measurment with high-resolution alpha spectrometry (PIPS detector)

15 Results

16 Budapest Sample 234 U [mbq/l] 238 U [mbq/l] 234 U/ 238 U ratio Bp-1 < MDA < MDA - Bp-2 < MDA < MDA - Bp ± ± 1.0 2,67 Bp ± ± 0.7 1,06 Bp-5 < MDA < MDA - The U concentration was very low In most cases we get results below the detection limit The ratio was shifted in one case (Bp-3) Minimum detectable activity : 1 mbq/l

17 U concentration [mbq/l] Bátaapáti I The highest U concentration was in the operating area U-234 U-238 The granite rocks during the mining activities were fragmented The U isotopes can get out, and get to the water 0 Ba-1 a Ba-1 b Ba-2 a Ba-2 b Ba-3 Ba-4 Ba-5 Ba-6 Sample

18 Bátaapáti II. Sample 234 U/ 238 U ratio Ba-1 a 4.12 Ba-1 b 5.54 Ba-2 a 4.07 Ba-2 b 3.51 Ba Ba Ba Ba The isotopic ratio was shifted Mining activities rock movement U isotope easier to get into the groundwater surface water Fragmentation helps the matrix destructive effect ( 238 U decay) more intense release

19 Torna stream I th October th Marc 2011 Before the disaster the natural radionuclide concentration was higher U concentration [mbq/l] U-234 U-238 The red mud adsorbed the radionuclides After it reduced the U, Ra, Po concentration 0 Tp1-a Tp1-b Tp1-c Tp1-d Tp1-e Sample Tp1-f Tp1-a netural Next to the storage Somlójenő Városlőd 6 months later the concentration was similar, as before the disaster

20 Torna stream II. Sample 234 U/ 238 U ratio Tp-1 a 0.86 Tp-1 b 0.9 Tp-1 c 0.87 Tp-1 d 1.04 Tp-1 e 1.03 Tp-1 f 1.21 Tp-1 a neutral Next to the storage Somlójenő 0.78 Városlőd 0.88 The isotope ratio was close to the equilibrium In a few points shifted

21 Conclusion Budapest The U concentration was low in the case of samples from Budapest 3 samples of 5 were under MDA Bátaapáti Highest U concentration in the operating area Isotopic ratio was shifted The granite rocks were fregmented during the mining activities The U isotopes can get out, and get to the water The U can get far with the water, so increases the radiation exposure of the population Torna stream Before the disaster the natural radionuclide concentration was higher After the accident the U, Ra, Po concentrations were reduced Red mud adsorbed the radionuclides 234 U/ 238 U isotope ratio was close to the equilibrium state 6 months after the disaster the natural radionuclide concentration was similar, as before the disaster

22 Comparison U concentration [mbq/l] ,23 43,9 The measurements system was controlled with IRRM sample Are our results representative? IRRM REM 2008 interlaboratory comparison material Acceptable 21,88 21,7 IRMM Our laboratory U-234 U-238

23 Köszönöm a figyelmet Thank You for your kind attention!