Environmental Radioactivity for Earth Scientists Heinz Surbeck

- A short nuclear physics primer - Cosmogenic radionuclides - Anthropogenic radionuclides - Measurement methods - Uranium and Thorium series - A short nuclear physics primer - Cosmogenic radionuclides - Anthropogenic radionuclides - Measurement methods - Uranium and Thorium series 1 Å = 10 -10 m

Electrons, negatively charged Nucleus nucleus / atom ~ 1/10‘000 10 fm = 10 -14 m

Protons, Neutrons, no positively charged electric charge

Number of electrons = number of protons (atomic number)

Chemical properties Physical properties, Neutral atom modified by number of neutrons, name atomic mass = number of protons + number of neutrons

137Cs (sloppy notation : Cs-137)

isotopes : same number of protons (p), but different number of neutrons (n) radionuclide or radioisotope : unstable nucleus

135Cs : 55 p, 80 n, stable

134Cs : 55 p, 79 n, 2 y 137Cs : 55 p, 82 n, 30 y half life, time until half of the nuclides have decayed Energy in eV (electron volt)

Electron Vacuum kinetic energy : 1 keV

- + HV, 1 kV Energy needed to heat up 1 g of water by 1 K : 1 cal = 4.2 Joule 1 eV = 1.6 . 10-19 Joule 10 MeV = 1.6 . 10-12 Joule

E = m . c2 2.6 . 1012 e- @ 10 MeV m = me (electron mass)

E = 511 keV Radioactive decay

historical reason for the names

electromagnetic radiation g wave / particle equivalence : photon

a radioactive source magnetic field Alpha particle

Beta particle (electron or positron)

Gamma ray Nucleus Alpha decay

Alpha particle = 4He 3 to 9 MeV

4.5 . 10 9 y 238U a 4.2 MeV

24.1 d - 234 e 318 keV recoil energy Th

Z = Z - 2 ~ 100 keV M = M - 4 z = atomic number = number of protons Beta decay

beta particle (electron or positron) keV to MeV

gamma ray, keV to MeV neutrino or Z = Z + 1 30.2 y antineutrino M = M - 137Cs e 514 keV

2.6 m 661 keV 661 keV

137Ba beta without gamma : 3H, 14C, 90Sr Interaction with matter

50 mm

Alpha

mm Beta

d1/2 : < mm to tens of cm Gamma / X

d1/2 : mm to tens of cm Neutron

Radionuclide Dose Sievert (Sv) 1 Becquerel (Bq) = 1 decay / s (Swiss mean : 3 mSv/y) - A short nuclear physics primer - Cosmogenic radionuclides - Anthropogenic radionuclides - Measurement methods - Uranium and Thorium series 7 Be, T 1/2 = 53 d spallation or cosmic ray 10 Be, T 1/2 = 1.4 My

3 H, tritium, T 1/2 = 12 y O or N others

neutron 3 H, tritium, T 1/2 = 12 y

14N 12C, stable

neutron proton

14 14 N C, T 1/2 = 5’700 y cosmic ray

Stratosphere 14C 3H ~ 10 km 7Be Troposphere

T = 5’700 y 14C 3 1/2 7Be H T 1/2 = 12 y

T 1/2 = 53 d

groundwater, natural level ~ 1 Bq/liter dead wood 14C / 12C -> age - A short nuclear physics primer - Cosmogenic radionuclides - Anthropogenic radionuclides - Measurement methods - Uranium and Thorium series Slow neutron induced fission

capture probability >> for slow neutrons than for fast neutrons --> moderator needed for chain reaction

M ~ 130 to 140

e.g. 137Cs slow neutron

~ 2 fast neutrons

235U M ~ 90 to 100

e.g. 90Sr

total energy released ~ 200 MeV

fissible U isotope, 238U not fissible by neutron capture C.-C. Su, C.-A. Huh /Marine Geology 183 (2002) 163 -178 Tritium (3H) in Swiss precipitations 300 Bq/liter

Etcheverry David, Vennemann Torsten 2009: Isotope im GrundwasMethoden zur Anwendung in der hydrogeologischen Praxis. UmweWissen Nr. 0930. Bundesamt für Umwelt, Bern. 121 S. 14C in air Der Spiegel, 2009 - A short nuclear physics primer - Cosmogenic radionuclides - Anthropogenic radionuclides - Measurement methods - Uranium and Thorium series How to detect gamma rays

Gamma spectrometry

high purity Ge single crystal (HPGe), LN2 cooled Bias holes electrons + voltage Bias depleted + voltage - region (cm)

Gamma ray

radionuclide R

sample Equivalent circuit How to detect gamma rays sample

Canberra Gamma spectrum from the fallout sample smeared on the vinyl sheet on the ground (red) at 9:30 March 15, 2011, and the background (blue). Sample taken on AIST Tsukuba site , close to Tokio.

source : AIST homepage Liquid Scintillation Counting

„blue“ photon Alpha or Scintillator Energy beta molecule levels particle

radionuclide

Counter or Photomultiplier spectrometer

Organic solvent + scintillator 226Ra Adsorption on thin film

1600 y

224Ra a spectrometry 3.6 d (semiconductor detector)

> 90% @ 100 ml, 6 h MnO2 thin film Detection limit : 5 mBq/l

PA66 substrate Thin film

100 ml sample Alpha spectrometry

electrons holes Bias voltage + + n-type Si Bias voltage - depleted region (100 µm) p-type contact

sample alpha particle

Equivalent circuit 400 Mineral water PEDRAS vintage 1996 226Ra 218Po 300 214 222Rn Po Counts per channel

200

100

220Rn 226 210 224 Ra Po Ra 216Po

0 4000 5000 6000 7000 8000

Energy [keV] 238 234Th U 24 d 4.5 E 9 y Adsorption on thin film

234mPa 1.2 m

234U a spectrometry (semiconductor detector) 2.5 E 5 y

> 80% @ 100 ml, 20 h Ion exchange resin (µm), Diphonix Detection limit : 5 mBq/l

PMMA substrate Mineral water « Ancienne », Aproz 80

238 U 234 U Tracer added

40 232U ~ 200 mBq/l counts/channel

235 20 U

0 3000 4000 5000 6000 Energy [keV] Radon in water measurement by the “bubbler method”, batch measurement

Radon-in-air monitor

Air in Air out

Ostwald coefficient

= C Rn,water /C Rn,air

~ 0.25 @ 20°C Radon in water measurement by the “bubbler method”, batch measurement Continuous Radon-in-water measurement

Air CO2 monitor

Radon-in-air monitor CO2 Rn Rn Water Rn CO2 Membrane-tube Rn i.d. 5.5 mm, wall 1.5 mm Rn 24 ml / m, 200 cm2 / m CO Rn 2 T1/2 approx. 3 min. for Rn, Rn less for CO2 CO2 Lucas cell Radon-in-air monitor

Light Scintillation Plexiglass window air out

Photomultiplier

air in

Alpha ZnS(Ag) layer particle

Counter Semiconductor detector Radon-in-air (RAD 7) monitor Air in

Positively charged ion, collected on detector

Hemisphere Rn Po

Electric field

Air out

- High + voltage Semiconductor detector Spectrometer and counter Printer - A short nuclear physics primer - Cosmogenic radionuclides - Anthropogenic radionuclides - Measurement methods - Uranium and Thorium series

222Rn : 650 Bq/l Toxic uranium in mineral water

Gesundheitstipp Juni 2006 WHO and new Swiss limit : 30 mg/liter, ~ 750 mBq (234U+238U)/liter artificial natural 1 210 Pb 0.5 > 100 Bq/kg in 226 239 Ra seafood Pu 210 Po 0.2 (Portugal)

0.1

0.05 238 U 90 Sr Dose factor [µSv/Bq]

Radiotoxicity 0.02 137 Cs 0.01 234Th 238U

24 d 4.5 E 9 y

234mPa 1.2 m

27 m 3.1 m 214Pb 218Po 222Rn 226Ra 230Th 234U 3.8 d 1600 y 75000 y 2.5 E 5 y 214Bi 20 m

210 Pb 214Po 1 E -4 s 22 y Alpha-decay 5 d 210Bi Beta-decay

206 Pb 210Po 138 d stable Alpha-decay 228Ra 232Th Beta-decay 5.7 y 1.4 E 10 y

6.1 h 228Ac

212Pb 216Po 220Rn 224Ra 228Th

11 h 0.15 s 56 s 3.6 d 1.9 y

208Tl 212Bi 61 m 3 m

212Po 208Pb 3 E -7 s stable 231Th 235U natural activity ratio 235U / 238U = 4.6 % 26 h 7 E 8 y

227Ac 231Pa 22 y 3.3 E 4 y

211Pb 215Po 219Rn 223Ra 227Th 36 m 2 E -3 s 4 s 11 d 19 d

210Tl 211Bi 5 m 2 m

Alpha-decay 207Pb stable Beta-decay Natural series 222 Rn 223 Ra 228 Ra 226 Ra 234 U 235 U 238 U 220 Rn soluble 224 Ra 212 Pb 210 Bi 227 Ac

occasionally soluble 228 Ac 210 Pb 234 Th 210 Po 228 Th 231 Pa 230 Th 231 Th 232 Th insoluble 227 Th 234m Pa 238 U series

232 Th series 10-4 10-310-2 10-1 100 101 102 103 104 105 106 107 108 109 1010

235 U series (activity 5% Half life [y] of 238 U series) Rn Ra

Soluble under 222 226 reducing U6+ --> U4+ conditions Rn Ra Ra 220 224 228

bacteria Rn U U 222 Soluble under 234 238 oxidizing Radium conditions adsorbed on Rn

220 hydroxides

238 U series 10-4 10-310-2 10-1 100 101 102 103 104 105 106 107 108 109 1010 232 Th series Half life [y] Radon as a natural tracer T1/2 = 3.8 days omnipresent, but generally diffuse sources

Rn Rn Rn Rn Rn Rn Rn Rn 10 days Rn Rn Rn Rn 20 days Rn Rn Rn short half life Rn Rn

useful to study fast transport processes exceptions ? Exceptions

well localized source no radon at start Soil Rn Rn produced in alluvial material

river : Rn = 0

Rn Rn Rn Rn Rn Karst Rn Rn Rn

Rn Rn Rn

infiltrating water takes up radon Training site Buix 8

7 Buix 6 5

Captage H [Bq/l]

3 3

2 Madonne Allaine 1

0 B14 0 2 4 6 8 10 12 14 16 222 Rn [Bq/l]

Hugli

S11 Grandgourt S10 Volcan CFF N

1 km 226Ra in soil of the 5000 Swiss Jura Mountains

2000

1000

500

"U" [Bq/kg] 200

100

“average" rocks and soils in Switzerland 50 100 200 500 1000 2000 5000 "Th" [Bq/kg] Distribution after : Labhart T.P. und Rybach L., Granite und Uranvererzungen in den Schweizer Alpen, Beiträge zur Geologie der Schweiz, Kleinere Mitteilungen, Nr. 60, Kümmerly & Frey, Bern, 1974 Rn CO2

Precipitation Sinkhole

Soil Rn CO2

Epikarst

Karst

? ? Spring Milandre cave Heavy storm

Rain Minor storm

450 8 3.5

400 7 3.0 350 CO 6 2 2.5 300 5 250 2.0

222 [vol%]

Rn 2 Rn [Bq/l] 4 CO 200 222 Flow rate [l/s] 222Rn 1.5 3 CO2 150 Flow rate 1.0 2 100 0.5 50 1 Flow rate

0 0 0.0 1.9.02 3.9.02 5.9.02 7.9.02 9.9.02 30.8.02 13.9.02 15.9.02 17.9.02 11.9.02 Date

Milandre, reaction to storm events (Ludovic Savoy) Expected 222Rn equilibrium concentration in pore water, 50 % water saturated

Emanation coefficient e = 50 %

226Ra mainly at 50 grain surface Average 40 e = 20 - 25 %

30 e = 5 - 10 %

226 10 Ra mainly inside grain Rn in pore water, saturated zone [Bq/l] 222 0

0 50 100 150 soil 226Ra [Bq/kg]

Limestone Average Swiss soil 99 98

80 TI, Diss. Payot 1952, n = 57 70 GR, Diss. Deflorin 2004, n = 350 VS, 1995 - 2005, n = 44 50 CH, NAQUA - trend, 2005, n = 51

Cumulative frequency [%] 30 20

5 1 2 5 10 20 50 100 200 500 222 Rn [Bq/l] Hot spots

Eglisau Courtemaîche Magden

Rhäzüns / Rothenbrunnen

Fideris

Mt. Vully Ruen Moiry Disentis Yverdon Bergün Vals Leytron Baltschieder / Brigerbad Andeer Lü Leukerbad Lax Lavey

Salève Derborence Poschiavo Val-d‘Illiez

Martigny / Val de Trient Bovernier Aproz / Combioula Saxon Stabio Nendaz 226Ra > 50 mBq/l „Limestone“ springs or wells with 228Ra > 50 mBq/l thermal anomaly and increased 226Ra and/or 222Rn concentrations 222Rn > 100 Bq/l 238U + 234U > 300 mBq/l 222Rn [arb. units] How high Rn concentrations may be 100 produced 75 ( > 50 Bq/l ) 50

Residence 0 time [d] 0 4 8 12 16 20 24

Reducing conditions Oxidizing conditions Fe-Ox precipitation no Rn high Rn Ra-adsorption on Fe-Ox low Ra high Ra As-adsorption on Fe-Ox low Fe high Fe anoxic Deep (thermal) groundwaters are anoxic

François Gainon, Les isotopes radioactifs de la série de l’uranium-238 (222Rn, 226Ra, 234U et 238U) dans les eaux thermales de Suisse, thesis, Université de Neuchâtel, 2008 Eglisau Courtemaîche Magden

Rhäzüns / Rothenbrunnen

Fideris

Mt. Vully Disentis Ruen Moiry Yverdon Bergün Vals Leytron Baltschieder / Brigerbad Andeer Lü Leukerbad Lax Lavey

Salève Derborence Poschiavo Val-d‘Illiez

Val de 350 Trient, Nendaz, 300 Leytron Visp-Brig 250 Aix-en-Provence *) 200

150 Rn [Bq/l] Leukerbad 222 100 50 micro-g HAsO -/l 50 4

0 40 80 120 160

226Ra [mBq/l]

*) Yanick Lettry, Resource hydrothermale du bassin d‘Aix- en-Provence, MSc thesis, Univ. of Neuchatel, 2002 Eglisau Courtemaîche Magden

Rhäzüns / Rothenbrunnen

Fideris

Mt. Vully Ruen Moiry Disentis Yverdon Bergün Vals LeytronBaltschieder / Brigerbad Andeer Lü Leukerbad Lax Lavey

Salève Derborence Poschiavo Val-d‘Illiez

20 Activity [Ra, U : mBq/l, Rn Bq/l]

0 7.6.05 25.1.05 23.2.05 22.3.05 21.4.04 19.5.04 10.6.04 30.6.04 19.7.04 18.8.04 30.9.04 27.4.05 18.5.05 28.6.05 19.10.04 22.12.04 23.11.04

Sampling date

Radium, radon and uranium time series for the thermal spring „Source de Leytron“. Error bars are 1s counting statistics. The line connecting the radon values is only a „guide to the eye“ with no physical meaning. Travertine with Ra adsorbed on Fe- und Mn- hydoxides

„high flow regime“, high Rn- concentration, Ra adsorption inreases

Spring

„low flow regime“, low Rn-concentration, Ra adsorption decreases Eglisau Courtemaîche Magden

Rhäzüns / Rothenbrunnen

Fideris

Mt. Vully Ruen Moiry Disentis Yverdon Bergün Brigerbad Vals Leytron Andeer Lü Leukerbad Lax Lavey

Salève Derborence Poschiavo Val-d‘Illiez

Martigny / Val de Trient Bovernier Aproz / Combioula Saxon Stabio Nendaz 226Ra > 50 mBq/l „Limestone“ springs or wells with 228Ra > 50 mBq/l thermal anomaly and increased 226Ra and/or 222Rn concentrations 222Rn > 100 Bq/l 238U + 234U > 300 mBq/l Cold water component Brigerbad, Valais, Switzerland

Warm water high Rn low Ra low Fe Oxygen rich cold water Spring

FeOx precipitation, Ra adsorption, Mixing zone Rn production

Anoxic hot water high Ra no Rn Thermal water component high Fe Brigerbad, Olivier Kloos

700 222Rn 600 226Ra 238U + 234U

500 Q6 Egg 3 400 TQB3 300 TQB1 TQB2 200

Activity [Bq/l for Rn, mBq/l Ra and U] 100

0 0 10 20 30 40 50 60 T [°C]

Olivier Kloos,Hydrochimie et hydrogeologie des sources thermales de Brigerbad (Valais), MSc thesis, Univ. of Neuchatel, 2004 François Gainon, Les isotopes radioactifs de la série de l’uranium-238 (222Rn, 226Ra, 234U et 238U) dans les eaux thermales de Suisse, thesis, Université de Neuchâtel, 2008 François Gainon, Les isotopes radioactifs de la série de l’uranium-238 (222Rn, 226Ra, 234U et 238U) dans les eaux thermales de Suisse, thesis, Université de Neuchâtel, 2008 Temperature of the thermal component at the mixing zone

François Gainon, Les isotopes radioactifs de la série de l’uranium-238 (222Rn, 226Ra, 234U et 238U) dans les eaux thermales de Suisse, thesis, Université de Neuchâtel, 2008 Buda Thermal Karst

Radionuclides as natural tracers for the characterization of fluids in regional discharge areas, Buda Thermal Karst, Hungary, Anita Eross , Judit Madl-Szonyi, Heinz Surbeck, Akos Horvath, Nico Goldscheider, Anita E. Csoma, Journal of Hydrology 426–427 (2012) 124–137 Phosphates

« there is a natural and unavoidable connection between phosphate mining and radioactive material. It is because phosphate and uranium were laid down at the same time and in the same place by the same geological processes millions of years ago. They go together. Mine phosphate, you get uranium » 50 to 200 ppm uranium ( 600 to 3’000 Bq/kg) phosphate rock U Ra U Ra sulfuric acid Radon emanation

phosphoric acid + phosphogypsum U Ra ammonia U : 1’000 Bq/kg Ra : 5’000 Bq/kg diammonium phosphate

Typical values for Central Florida U : 4’000 Bq/kg Ra : 1’000 Bq/kg 5000 phosphate rocks, Florida, North Africa

2000

1000

500

"U" [Bq/kg] 200

100

Eglisau Courtemaîche Magden Aeugst a.A.

Rhäzüns / Rothenbrunnen

Fideris

Mt. Vully Ruen Moiry Disentis Yverdon Bergün Vals Leytron Baltschieder / Brigerbad Andeer Lü Leukerbad Lax Lavey

Salève Derborence Poschiavo Val-d‘Illiez

Martigny / Val de Trient Bovernier Combioula Saxon Stabio 226Ra > 50 mBq/l Aproz / Nendaz

228Ra > 50 mBq/l „Limestone“ springs or wells with thermal anomaly and increased 222Rn > 100 Bq/l 226Ra and/or 222Rn concentrations 238U + 234U > 300 mBq/l Mineral water « Ancienne », Aproz 80

238 U 234 U Tracer added

40 232U ~ 200 mBq/l counts/channel

235 20 U

0 3000 4000 5000 6000 Energy [keV] Clays, fossils, coal

Increased indoor gamma dose rates in houses built with bricks from "Ziegelei Düdingen" Les Dailles, Wallenried

OMM

clay

sandstone USM

Placer deposit in former creek, black sand with heavy minerals and gold, some 100 ppm uranium Eglisau Courtemaîche Magden Aeugst a.A.

Rhäzüns / Rothenbrunnen Mt.Vully Fideris

Ruen Moiry Disentis Yverdon Bergün Vals Leytron Baltschieder / Brigerbad Andeer Lü Leukerbad Lax Lavey

Salève Derborence Poschiavo Val-d‘Illiez

Martigny / Val de Trient Bovernier Aproz / Combioula Saxon Stabio Nendaz 226Ra > 50 mBq/l

228Ra > 50 mBq/l „Limestone“ springs or wells with thermal anomaly and increased 222Rn > 100 Bq/l 226Ra and/or 222Rn concentrations 238U + 234U > 300 mBq/l 40 35 30

25 g/l] m 20 15

10 Uranium [ 5 0

Samples taken 25.1.2007, measured by CHYN Mt. Vully Fe-hydroxides Radium adsorption bonebeds with uranium preciptated under anoxic Radon production conditions

Uranium remobilisation Rn under oxic conditions U Ra U U

high Rn high U low Ra

Bernd Schott & Jens Wiegand, Processes of radionuclide enrichment in sediments and ground waters of Mont Vully (Canton Fribourg, Switzerland, Eclogae geol.Helv. 96 (2003) 99-107 Eglisau Courtemaîche Magden

Rhäzüns / Rothenbrunnen

Fideris Mt. Vully Aeugst a.A. Ruen Moiry Disentis Yverdon Bergün Vals Leytron Baltschieder / Brigerbad Andeer Lü Leukerbad Lax Lavey

Salève Derborence Poschiavo Val-d‘Illiez

Martigny / Val de Trient Bovernier Aproz / Combioula Saxon Stabio Nendaz 226Ra > 50 mBq/l

228Ra > 50 mBq/l „Limestone“ springs or wells with thermal anomaly and increased 222Rn > 100 Bq/l 226Ra and/or 222Rn concentrations 238U + 234U > 300 mBq/l 238U 234U

235U

Bergwerk Riedhof, sample R5, September 10, 2007, sampled by Anja Studer Diamond irradiation in natural fluid environments

Alpha particle from decaying adsorbed radon daughter Ferric hydroxide precipitates adsorbing radium ions, bombarding the surface layer followed by release of radon gas

Oxygen rich near-surface water

Implantation of radon progeny, e.g. 210Po

Radon and radon Gamma ray daughter isotopes High radon Anoxic (reducing) and radioactive fluids concentration in carrying dissolved iron and radium ions fluid environment

C 2007, Nucfilm Products, Dr.H.Surbeck 350 210 BM1916.34, 10'000 s 300 Po

250

200

150

100 4 mm Counts/channel + 1

0 2000 3000 4000 5000 6000 7000 8000 Energy [keV]

Alpha spectrum of a green diamond irradiated with a radium salt around 1910 by Sir William Crookes. Measured (in air) 2004 in the Natural History Museum London by George Bosshart. 10000 Diamond FN 1286 Po-210

1000

100

Counts/channel + 1 Ra-226 Rn-222 Po-214 10 Po-218

1 4500 5000 5500 6000 6500 7000 7500 8000 Energy [keV] Alpha spectrum of a diamond (13 ct) irradiated wit radium, probably around 1965 in Russia. Total activity : ~ 500 Bq 210Po. Measured in vacuum. Other gemstones

Zircon samples 238U series 90

80 Pb-214 Pb-212 70 232Th series 60

30 Activity concentration [Bq/g] 20

10 „Average rock“ : 0.05 Bq/g 0 0 5 10 15 20 25 30 Weight [ct] Dating by U/Pb ratio 238 234Th U 24 d 4.5 E 9 y

234mPa 1.2 m

27 m 3.1 m 234 214Pb 218Po 222Rn 226Ra 230Th U 3.8 d 1600 y 75000 y 2.5 E 5 y 214Bi 20 m

210 Pb 214Po 1 E -4 s 22 y Alpha-decay 5 d 210Bi Beta-decay

206 Pb 210Po 138 d stable Rare earths NiMH-battery contains LaNi5

Natural isotope : 138La Abundance : 0.07 % Half-life : 1.1e11 y, Gamma emitter : 788 keV, 1436 keV

About 5 Bq/battery Thorium Monazite Rare Earth Elements

Permanent magnets fresh Gas mantle Thorium, Yttrium, Cerium Natural isotope : 232Th Abundance : 100% Half-life : 1.4e10y Alpha emitter : 4-7 Mev in use approx. 1'000 Bq/gas mantle Permanent magnets Permanent magnets SmCo : Natural isotope : 147Sm Abundance : 15.1% Half-life : 1.06e11y Alpha emitter : 2.23 Mev approx. 150 Bq/g Sm Sludges

St. Placidus Rn : 650 Bq/l Aeration Quartz sand filter 226Ra : 30 mBq/l 226Ra : 20 - 25 mBq/l 228Ra : 180 mBq/l 228Ra : 120 - 150 mBq/l Fe : 3 mg/l Fe : 0.1 mg/l

Sludge Sludge from backwash from tubing Filter material Mineral 10000 Water 9000 8000 Plant 7000 6000 5000 50 mBq/l --> kBq/kg 4000 Ra [Bq/kg dry] 3000 228 2000 1000 0 0 200 400 600 800 1000 1200 1400

226Ra [Bq/kg dry] Aeration Quartz sand filter 226Ra : 30 mBq/l 226Ra : 20 - 25 mBq/l 228Ra : 180 mBq/l 228Ra : 120 - 150 mBq/l Fe : 3 mg/l Fe : 0.1 mg/l

Sludge Sludge from backwash from tubing Filter material Mineral Now : new 10000 filter added Water 9000 8000 MnO2 filter Plant 7000 6000 5000 50 mBq/l --> kBq/kg 4000 Ra [Bq/kg dry] 3000 228 2000 ~ 90 % of the 1000 radium adsorbed, 0 creating serious 0 200 400 600 800 1000 1200 1400 waste problem

226Ra [Bq/kg dry]

Geothermal Power Plant

Fluid batch samples

Sample 226Ra 228Ra 238U 234U [mBq/l] [mBq/l] [mBq/l] [mBq/l]

Well-2 844 ± 26 716 ± 41 5 ± 3 12 ± 4 Well-4 64 ± 8 69 ± 13 10 ± 4 < 5

Residue samples (mainly iron- and manganese- oxihydroxides)

Residue from filter Residue from tubing

Nuclide Activity [kBq/kg fresh] Nuclide Activity [kBq/kg fresh]

238U < 0.1 238U < 0.1 226Ra 16 ± 1 226Ra 8 ± 1 228Ra 7 ± 1 228Ra 4 ± 1 210Pb 137 ± 7 210Pb 178 ± 1 Thank you for your attention

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