PAUL SCHERRER INSTITUT Practical Approaches using TDCR Measurements and Alpha/Beta Separation Jost Eikenberg, Maya Jäggi, Andreas Brand Division for Radiation Protection and Safety Paul Scherrer Institute, CH-5232 Villigen Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Overview / Topics TDCR standardization measurements with typical isotopes from the nuclear fuel cycle Presentation of a radiochemical method for simultaneous determination of 210 Pb and 226 Ra+ 228 Ra Simultaneous determination of 241 Pu ( β -emitter) and 238 Pu, 239 Pu+ 240 Pu ( α -emitter) in nuclear materials Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT TDCR standardization measurements LSC measurements using pure β -emitting isotopes: 3 H, 63 Ni, 14 C, 36 Cl and 90 Sr/ 90 Y (isotopes in the order of increasing β -energy) Presentation of unquenched vs. quenched data Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT TDCR vs. Efficiency: all isotopes TDCR vs Efficiency: all nuclides, unquenched data 1 0.9 0.8 0.7 rel. TDCR 0.6 0.5 0.4 0.3 0.2 0.1 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900 1.000 rel. efficiency Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Tritium: 3 H (E max : 18.6 keV) TDCR vs Efficiency: H-3 0.5 0.4 rel. TDCR 0.3 0.2 0.1 0 0.000 0.100 0.200 0.300 0.400 0.500 rel. efficiency Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT 63 Ni (E max : 65.9 keV) TDCR vs Efficiency: Ni-63 1 0.9 0.8 0.7 rel. TDCR 0.6 0.5 0.4 0.3 0.2 0.1 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900 1.000 rel. efficiency Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Radiocarbon: 14 C (E max : 156 keV) TDCR vs Efficiency: C-14 1 0.9 0.8 0.7 rel. TDCR 0.6 0.5 0.4 0.3 0.2 0.1 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800 0.900 1.000 rel. efficiency Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT 36 Cl: (E max : 709 keV) TDCR vs Efficiency: Cl-36 1 0.9 rel. TDCR 0.8 0.7 0.6 0.5 0.500 0.600 0.700 0.800 0.900 1.000 rel. efficiency Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT 90 Sr/ 90 Y (E max : 546/2280 keV) TDCR vs Efficiency: Sr-90 1 0.9 rel. TDCR 0.8 0.7 0.6 0.5 0.500 0.600 0.700 0.800 0.900 1.000 rel. efficiency Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Environmental application: determination of 228 Ra, 226 Ra and 210 Pb in aqueous samples using TDCR measurement technique and α/β -separation Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT 238 U-Series 235 U-Series 232 Th-Series 238 U 234 U 235 U U 4.47x10 9 y 2.45x10 5 y 7.04x10 8 y β α α α 231 Pa 234 Pa Pa 4.196 4.776 4.395 MeV MeV MeV 3.28x10 4 y 1.17min β β α 234 Th 230 Th 231 Th 227 Th 232 Th 228 Th Th 5.013 7.54x10 4 y 1.41x10 10 y 24.1d 1.06d MeV 18.7d β 1.91y β α α α α 227 Ac 228 Ac Ac 4.688 6.038 4.010 5.423 MeV MeV MeV MeV 21.8y 6.13h β 226 Ra 223 Ra 228 Ra 224 Ra Ra 1600y 11.4d 5.75y 3.66d α α α Fr 4.784 5.716 5.686 MeV MeV MeV 222 Rn 219 Rn 220 Rn Rn 3.825d 3.96s 55.6s α α α At 5.490 6.819 6.288 MeV MeV MeV 218 Po 214 Po 210 Po 215 Po 216 Po 212 Po Po 66.3% 1.6x10 -4 s 1.8x10 -3 s 3x10 -7 s 3.11min β β 138.4d β 0.15s α α α α α α 214 Bi 210 Bi 211 Bi 212 Bi Bi 6.003 7.687 5.304 7.386 6.779 8.784 MeV 19.9min MeV MeV MeV β MeV β 1.01h MeV 5.01d 2.14min β β α 33.7% 214 Pb 210 Pb 206 Pb 211 Pb 207 Pb 212 Pb 208 Pb α Pb 6.623 6.051 MeV 10.6h 26.8min 22.3y stable 36.1min stable stable MeV β β 207 Tl 208 Tl Tl 4.77min 3.05min Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Th-Ra relationship in the 232 Th and 238 U decay series α ⋅ β ⋅ β 10 0 : . 140 10 a : 5 76 10 . a : 613 . h → → → + 232 228 228 228 Th Ra Ac Th daugthers α ⋅ β α 0 : . 19110 a → : . 3 66 d → : 55 6 . s → + 228 224 220 216 Th Ra Rn Po daugthers α ⋅ α ⋅ α 4 3 : 7 54 10 . a → : . 160 10 a → : . 382 d → + 230 226 222 218 Th Ra Rn Po daughters Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Continental water: relevant isotopes • Alpha-emitter: U-238, U-234 • Beta-emitter: Ra-228 (with fast ingrowing Ac-228) • Alpha-emitter: Ra-226 (with Rn-222 prognies) • Beta-emitter: Pb-210 (with ingrowing Bi-210) • Alpha-emitter: Po-210 Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Schematic view of radioactive transformation 226 Ra (1600 y) Z = 88 0.0 α 2 (4.5 %) 0.186 γ 1 α 1 (95.5 %) 0.0 Z = 86 222 Rn (3.82 d) → + + . 226 222 4 4 78 Ra Rn He MeV 88 86 2 Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT relevant isotopes in continental water and their measurement methods at PSI radionuclide analytical technique 234 U, ( 235 U), 238 U U/TEVA separation, electro- deposition, α -spectrometry 226 Ra, 228 Ra, 210 Pb filtration (RadDisc), OptiPhase Hisafe3 cocktail, LSC 210 Po spontaneous deposition on silver disc, α -spectrometry Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Relationship parent / daughter parent half-life ingrowing half-life isotope parent daughter daughter 210 Pb ( β ) 210 Bi ( β ) 22.3 years 6.02 days 226 Ra ( α ) 222 Rn ( α ) 1602 years 3.82 days 228 Ra ( β ) 228 Ac ( β ) 5.76 years 6.13 hours Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Method implementation: low level determination of 210 Pb, 226 Ra+ 228 Ra in drinking water • Filtration of the sample (2 liter) through 3 Empore RadDisc (Mn-oxide impregnated) membrane filters • Elution of Pb with Diammonium Hydrogen Citrate • Elution of Ra with alkaline Na-EDTA solution • Measuring via LSC with optimized α/β - discrimination Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Classical two photomultiplier LS electronic set-up Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Pulse shape α/β discrimination 1200 1000 alpha-pulse relative intensity 800 600 400 beta-pulse 200 0 20 40 60 80 100 120 140 160 pulse decay time [ns] Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Spill-over α/β determination 14 12 β in α α in β 10 spillover [%] 8 6 4 2 0 100 110 120 130 140 150 discriminator setting [ns] Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT The triple coincidence to double coincidence ratio (TDCR) counting technique PM R SAM PLE PM PM S T Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT Pulse Length Index (PLI) discrimination with HIDEX SL 300 28 24 20 16 12 8 4 0 27 38 52 72 99 135 185 252 343 466 634 861 1169 1588 2156 2927 3973 5393 7319 9934 13481 18296 Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT α -spectrum of 226 Ra with ingrowing daughters 2 h and 8 h after separation using HIDEX 300 SL LSC Alpha 140 120 100 80 60 40 20 0 10 100 1000 10000 Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT α -spectrum of 226 Ra with ingrowing daughters obtained 6 days after separation Alpha 160 140 120 100 80 60 40 20 0 10 100 1000 10000 Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT β -spectrum of 214 Bi/ 214 Pb obtained 6 days after separation ( 226 Ra/ 222 Rn decay series products) Beta 35 30 25 20 15 10 5 0 1 10 100 1000 Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
PAUL SCHERRER INSTITUT β -spectrum of 228 Ra with ingrowing 228 Ac 1 h and 8 h after separation using HIDEX 300 SL LSC Beta 50 45 40 35 30 25 20 15 10 5 0 1 10 100 1000 Paul Scherrer Institut • 5232 Villigen PSI LSC Int. Conference, Copenhagen, 01-05.05.2017
Recommend
More recommend
