The Fifth Conference “ Nuclear Science and Its Application”, 14-17 October 2008
CONCENTRATIONS OF NATURAL RADIONUCLIDES IN
COMBUSTIBLE SLATES
A.N .A ZIM O V 1.1.T. M UM INO V2, A .K .M U H A M ED O V 1, A .A .SA FA R O V ', A .N .SA FA R O V 1. 1 Sam arkand State University.
2 Research Institute o f A pplied Physics, N ational U niversity o f Uzbekistan.
In current w ork decom position technique [1] o f scintillation y-spectra o f com bustible slates sam ples is dem onstrated. The m easurem ents w ere done on y-spectrom eter w ith N al(T l) crystal, 0 6 3 x 6 3 m m , AE^/1332 keV = l 0%. Sam ples were herm etically packed into one liter M arinelli beakers (sam ple density p=925g/l). Efficiency calibration o f spectrom eter and decom position o f spectra to its com ponents w ere done using standard sources 226R a(A = 8147(570) Bq), 232T h(A =7349(514) Bq) and 40K (A =13790(965) Bq) from O M A CH set.
Spectra o f sam ples are caused by radiations o f natural radionuclides 40K, 235U , daughter R N s o f 226R a sub row (214Pb, 214Bi) and row 232Th (228Ac, 212Pb and20STl). Spectrum o f sam ple can be presented as following:
S = S t a + S T*+ S K+ S U+ F ’
w here S.-components o f corresponding RNs, F- background. The “reduced” inert spectrum w as taken as background com ponent o f sam ple w ith density p [1],
A ctivities o f 226Ra, 232Th and w ere determ ined using norm alized spectra ERa, E Th, EK o f standard sources, for 235U - by intensity - I (area) o f total absorption peak 185,7 keV 235U, registration efficiency -e^,quantum yield-a^ and m easurem ent tim e-t: A ^ A a t .
Spectra decom position procedure is illustrated in F ig.l
The Fifth Conference “ Nuclear Science and Its Application”, 14-17 October 2008
Fig. 1. Spectrum o f sam ple - S and its com ponents F, Elu (687(70) Bq/kg), ETh (24(3) B k/kg), EK (268(30) Bq/kg), Sy (39(4) Bq/kg). S -S -F , S r S0-ERa, S = S 1-ETh, SU= S 2-EK.
Reference
1. A.N Azimov, Sh. Kh. H ushm uradov, I. T. M uminov, T. M . M um inov, B. S. Osmanov, A. N. Safarov, A. A. Safarov, Gam m a spectrom etric determ ination o f natural radio nuclides and 137Cs concentration in environm ental samples. The im proved Scintillation technique, R adiation m easurem ents, 43 (2008), p 66-71.
Section II. Basic Problem s O f N uclear Physics 31
