release of natural radionuclides from norm-residues caused by sewage j. dilling 1, k. flesch 2, r....
DESCRIPTION
— inhalation of Radon and its decay products — inhalation of contaminated dust — direct ingestion of contaminated soil — exposure to external gamma radiation — ingestion of locally produced food (incl. drinking water) Dose assessment Pathways of concern grown on contaminated sites irrigation with contaminated waterTRANSCRIPT
Release of natural radionuclides from NORM-residues
caused by sewage
J. Dilling1, K. Flesch2, R. Gellermann3, J. Gerler1, H. Hummrich2, V. Neumann4, R. Knappik5, H. Schulz2
1Federal Office for Radiation Protection, Berlin2IAF - Radioökologie GmbH, Dresden 3FUGRO-HGN GmbH, Magdeburg4BGD, Dresden5VKTA, Rossendorf
2nd Workshop of the European ALARA Network for NORM, Dresden 2009
Legal Framework
Introduction of surveillance limits depending on the recycling or disposal option
If exceeding SLs
site specific dose assessments (realistic scenarios, parameters,
models)
formal release of surveillance necessaryPrecondition: D < 1mSv/a (members of the public)
Radiation Protection Ordinance Positive List
joint disposal depending on specific activity and landfill
parameters
— inhalation of Radon and its decay products
— inhalation of contaminated dust
— direct ingestion of contaminated soil
— exposure to external gamma radiation
— ingestion of locally produced food (incl. drinking water)
Dose assessment
Pathways of concern
grown on contaminated sites
irrigation with contaminated water
Dose assessment
Pathway: Ingestion of locally produced food
focussing on water
disposed or recycled NORMseepage water
ground water
well surface water
source term: which radionuclide concentrations will be released?
Approach
Crosslink conventional hazards
Standard methods for assessing waste and contaminated soil regarding potential groundwater contaminations
Present study Feasibility study regarding methodical approaches
— soil saturation extract— pH-Stat — elution with water (1:10, 1:2 respectively)
— column experiments
Approach
Soil saturation extract (technical realisation)
original sample + deion. water to moisten completely , keeping 24 h at 5°C
adding water until flow limit is reached, keeping another 24 h at 5°C
centrifugation and filtration with membrane filters (pore size 0,45 µm)
original sample + deion. water to moisten completely , keeping 24 h at 5°C
adding water until flow limit is reached, keeping another 24 h at 5°C
centrifugation and filtration with membrane filters (pore size 0,45 µm)
Methodical advantages and disadvantages — close to reality material/water ratio (+)
— no fixed water / solid ratio (-)
— small sample volume (5-30ml /100g) (-)
— not convenient for very fine and very coarse textured material (-)
Approach
Soil saturation extract
Approach
pH-Stat (technical realisation)
field moist sample + deion. Water (1:10),
24 h stirring, adding HNO3 by means of an automatic titrator until pH 4
filtration with membrane filters (pore size 0,45 µm)
Approach
pH-Stat
field moist sample + deion. Water (1:10),
24 h stirring, adding HNO3, by means of an automatic titrator until pH 4
filtration with membrane filters (pore size 0,45 µm)
Methodical advantages and disadvantages
— determination of the leachable contaminants according to a worst-case scenario (+)
— information of buffering capacity (+)
— no pH-Stat experiment at low pH value (<4) (-)
Approach
Elution with water 1:10 and 1:2 (technical realisation)
field moist sample + deion. Water (1:10, 1:2 respectively)
24 h overhead-rotating shaker at room temperature
filtration with membrane filters (pore size 0,45 µm)
Approach
Elution with water 1:10 and 1:2
field moist sample + deion. Water (1:10, 1:2 respectively)
24 h overhead-rotating shaker at room temperature
filtration with membrane filters (pore size 0,45 µm)
Methodical advantages and disadvantages
— leachate volume large enough for the following analysis (+)
— abrasion of particles during the extraction procedure (-)
— 1:10 material/water ratio: excess water1:2 material/water ratio closer to reality (see soil sat. Extract)
Approach
Column experiment – experimental setup
insert sample in column, wetting from downside up within 24 h
keeping 24 h at 10°C
exchange of one pore volume within 24 h
intermittently driven
6-20x
0,0
0,4
0,8
1,2
0 5 10 15 20PV
Pi/P
i 1
EC pH Redox I
Approach
„steady-state“
Column experiment – end of experiment„quasi steady state“ situation
no alteration in physico-chemical properties like pH, redox-potential
Approach
„steady-state“
0,0
0,4
0,8
1,2
0 5 10 15 20PV
Pi/P
i 1
EC pH Redox I Redox II
Column experiment – end of experiment„quasi steady state“ situation
no alteration in physico-chemical properties like pH, redox-potential
Approach
Determining the source term
column experiment
C
t
soil saturation extract
elution with water 1:10elution with water 1:2
t
different concentrationlevels expected !!
Approach
28 different NORM residues investigated— slags from primary metallurgic processes in the raw iron and non-ferrous
metallurgy
— sludges and dust from the smoke gas filtering with the primary metallurgic processes in the raw iron and non-ferrous metallurgy
— sludges and sediments from the recovery of oil and natural gas (Scales)
— red mud from the extraction of bauxite
— tailings from the extraction of uranium
— residues of water treatment facilities
Approach
— U-238 series: U-238, Th-230, Ra-226, Pb-210, (Po-210) — U-235 series: Ac-227 — Th-232 series: Ra-228, Th-228, (Th-232) — K-40
• Residue
— U-238, Ra-226, Pb-210, Ra-228 (Th-228, Ac-227, Po-210)— Major ions: Cl-, HCO3-, SO4
2-, Na+, K+, Ca2+, Mg2+ — pH, electrical conductivity
• Leachate
• Analysing methods— Gamma spectrometry— Alpha spectrometry— Liquid Scintillation Counting (LSC)— ICP-MS
Analysed parameters
ResultsData mining
activity-concentration scaled on pore volume ai
PV of undisturbed soil:
nWFa
a di
i leachate
PV
ai
leachate: activity-concentration in leachate [Bq/l]
WF: Water/material ratio [l/kg]d: oven-dry density [g/cm³]n: porosity
i
ileachate
i AWFa
R
leachable fraction Ri:
Ai: specific activity [Bq/kg]
Different water / solid ratios results not comparble normalisation required
ResultsU-238 activity concentration scaled on pore volume
Due to the acidification during the pH-Stat experiment trends to result in highest concentration
1E+0
1E+1
1E+2
1E+3
1E+4
1E+5
1E+6
1E+7
Ni-s
lag
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gsw
w fi
lter
grav
elw
w fi
lter
grav
elw
w fi
lter
grav
el
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
mB
q/l
U-238 (1+10)U-238 (pH-Stat)U-238 (SSE)U-238 (1+2)
furn
ace
gas
slud
ge1E+0
1E+1
1E+2
1E+3
1E+4
1E+5
1E+6
1E+7
Ni-s
lag
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gsw
w fi
lter
grav
elw
w fi
lter
grav
elw
w fi
lter
grav
el
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
mB
q/l
U-238 (1+10)U-238 (pH-Stat)U-238 (SSE)U-238 (1+2)
furn
ace
gas
slud
gefu
rnac
e ga
s sl
udge
ResultsU-238 leachable fraction
Tailings: close to 100% release feasible
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1E+0N
i-sla
g
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gs
ww
filte
rgr
avel
ww
filte
rgr
avel
ww
filte
rgr
avel
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
U-238 (1+10)U-238 (pH-Stat)U-238 (SSE)U-238 (1+2)
furn
ace
gas
slud
ge
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1E+0N
i-sla
g
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gs
ww
filte
rgr
avel
ww
filte
rgr
avel
ww
filte
rgr
avel
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
U-238 (1+10)U-238 (pH-Stat)U-238 (SSE)U-238 (1+2)
furn
ace
gas
slud
gefu
rnac
e ga
s sl
udge
ResultsRa-226 activity concentration scaled on pore volume
Due to the acidification during the pH-Stat experiment trends to result in highest concentration
1E+0
1E+1
1E+2
1E+3
1E+4
1E+5
1E+6
Ni-s
lag
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gsw
w fi
lter
grav
elw
w fi
lter
grav
elw
w fi
lter
grav
el
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
mB
q/l
Ra-226 (1+10)Ra-226 (pH-Stat)Ra-226 (SSE)Ra-226 (1+2)
furn
ace
gas
slud
ge1E+0
1E+1
1E+2
1E+3
1E+4
1E+5
1E+6
Ni-s
lag
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gsw
w fi
lter
grav
elw
w fi
lter
grav
elw
w fi
lter
grav
el
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
mB
q/l
Ra-226 (1+10)Ra-226 (pH-Stat)Ra-226 (SSE)Ra-226 (1+2)
furn
ace
gas
slud
gefu
rnac
e ga
s sl
udge
ResultsRa-226 leachable fraction
Low leachable fraction for demercurised residues and scales
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1E+0N
i-sla
g
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gs
ww
filte
rgr
avel
ww
filte
rgr
avel
ww
filte
rgr
avel
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
Ra-226 (1+10)Ra-226 (pH-Stat)Ra-226 (SSE)Ra-226 (1+2)
furn
ace
gas
slud
ge
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1E+0N
i-sla
g
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gs
ww
filte
rgr
avel
ww
filte
rgr
avel
ww
filte
rgr
avel
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
Ra-226 (1+10)Ra-226 (pH-Stat)Ra-226 (SSE)Ra-226 (1+2)
furn
ace
gas
slud
gefu
rnac
e ga
s sl
udge
ResultsPb-210 activity concentration scaled on pore volume
Highest concentration due to the acidification during the pH-Stat experiment are evident
1E+01E+11E+21E+31E+41E+51E+61E+71E+81E+9
Ni-s
lag
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gsw
w fi
lter
grav
elw
w fi
lter
grav
elw
w fi
lter
grav
el
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
mB
q/l
Pb-210 (1+10)Pb-210 (pH-Stat)Pb-210 (SSE)Pb-210 (1+2)
furn
ace
gas
slud
ge1E+01E+11E+21E+31E+41E+51E+61E+71E+81E+9
Ni-s
lag
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gsw
w fi
lter
grav
elw
w fi
lter
grav
elw
w fi
lter
grav
el
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
mB
q/l
Pb-210 (1+10)Pb-210 (pH-Stat)Pb-210 (SSE)Pb-210 (1+2)
furn
ace
gas
slud
gefu
rnac
e ga
s sl
udge
ResultsPb-210 leachable fraction
Elevated leachable fraction for sinter dust and water work residues
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1E+0N
i-sla
g
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gs
ww
filte
rgr
avel
ww
filte
rgr
avel
ww
filte
rgr
avel
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
Pb-210 (1+10)Pb-210 (pH-Stat)Pb-210 (SSE)Pb-210 (1+2)
furn
ace
gas
slud
ge
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1E+0N
i-sla
g
Cu-
slag
phos
phat
esl
agTh
eise
nsl
udge
furn
ace
gas
sint
er d
ust
dem
.re
sidu
esde
m.
resi
dues
scal
es
red
mud
tailin
gs
tailin
gs
tailin
gs
ww
filte
rgr
avel
ww
filte
rgr
avel
ww
filte
rgr
avel
1.1 1.2 1.10 2.5 2.9 2.15 3.2 3.4 3.13 4.1 5.1 5.2 5.4 6.1 6.6 6.7
Pb-210 (1+10)Pb-210 (pH-Stat)Pb-210 (SSE)Pb-210 (1+2)
furn
ace
gas
slud
gefu
rnac
e ga
s sl
udge
Results
Data mining column experiments
i
iabs,ni
rel AmA
F
relative leached load Firel
m: mass of material in column [kg]Ai: specific activity [Bq/kg]
n
n,leachatei
n,leachateiabs,n VaA
1
ai
leachate,n: activity conc. in n-th leachate [Bq/l]
Vleachate,n
: volume n-th leachate [l]
total leached load Ain,abs
Results
Theisen sludge – intermittently driven column experiment
activity concentrationen
1E+0
1E+1
1E+2
1E+3
1E+4
0 2 4 6 8 10 12pore volume
mB
q/l
Ra-226 U-238Pb-210
leached activity (accumulated)
0,025
0,14
3,7
1E-3
1E-2
1E-1
1E+0
1E+1
0 2 4 6 8 10 12pore volume
Bq
Ra-226 U-238Pb-210
Results
Theisen sludge – comparison between different leaching methods
1E-7
1E-6
1E-5
1E-4
1E-3
1E-2
SSE CE1.leachate
CE10.leachate
pH-stat 1+10 1+2
rel.
leac
hed
load
U-238Ra-226Pb-210
Results
Tailings – intermittently driven column experiment
activity concentration
1E+0
1E+1
1E+2
1E+3
1E+4
1E+5
0 2 4 6 8 10
pore volume
mB
q/l
Ra-226U-238
leached activity (accumulated)
1,7
92
1E-1
1E+0
1E+1
1E+2
0 2 4 6 8 10pore volume
Bq
Ra-226U-238
Results
Tailings – comparison between different leaching methods
1E-7
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1E+0
SSE CE1.leachate
CE10.leachate
pH-stat 1+10 1+2
rel.
leac
hed
load
U-238Ra-226
Conclusions
— This present study is the first complex investigation about the release of radionuclides by sewage from NORM .
— The soil saturation extract offers only a marginal sample volume, meaning the determination of radionuclides is in many cases impossible.
— The elution with water is easy to handle and gives qualitative informations about the radionuclides released.
— Caused by the lowered pH of 4 the results of pH-Stat experiments show, as expected, higher activity concentrations compared to other methods.
Conclusions
— The realisation of intermittently driven column experiments is more sophisticated compared to batch experiments, but the results offer informations about time depending leaching of radionuclides.
— No alteration in the physico-chemical properties (e.g. pH and redox-potential) assumed the electric conductivity is a suitable parameter to determine „quasi steady-state“ conditions.
— The transferability of the well-established methods (elution with water, the pH-Stat, intermittently driven column experiments) from waste legislation on radiological purposes could be shown.
Thank you for your attention
Legal Framework
— sludges and sediments from oil and natural gas extraction
— unconditioned phosphor gypsum, dust, sludges and slags occurring during processing of raw phosphate
— waste rock, sludges, sands, slags and dusts from the extraction and preparation of bauxite, columbite, copper shale, tin…
— dust and sludge from smoke gas filtering within primary metallurgic processes in the raw iron and non-ferrous metallurgy
Exception: • C < 0,2 Bq/g• Introduced in technological processes specified in the positive list
as raw material
List of residues requiring surveillance (Radiation Protection Ordinance – RPO): “Positive List”
Legal Framework
— Based on Directive 96/29 EURATOM (European Basic Safety Standards) — Systematic research for identifying relevant processes and materials
— Radiological criterion: 1 mSv/a to members of the public (added to the natural background level)
— Results:
• fate of particular industrial residues of concern• U-238 and Th-232 series relevant
List of residues needing surveillance – Radiation Protection Ordinance (RPO 2001)
NORM residues
Slags from primary metallurgic processes in the raw iron and non-ferrous metallurgy
P1.1 Ni-Slags
P1.2 Cu-Slags
P1.3 Sandy residues from tin ore prosessing
P1.8 Casting cinder
P1.10 Phosphate slags
5 cm
P1.10
NORM residues
Sludges and dust from the smoke gas filtering with the primary metallurgic processes in the raw iron and non-ferrous metallurgy
P2.5 Theissen sludge
P2.9 Furnace gas sludges
P2.13 Sinter dust
P2.14 Furnace gas sludges
P2.15 Sinter dust
NORM residues
Sludges and sediments from the recovery of oil and natural gas (Scales)
5 cm5 cm
5 cm 5 cm
2 cm 2 cm
P3.2 P3.3
P3.4 P3.5
P3.13P3.6
P3.2 to P3.5 demercurised residues
P3.6 & P3.13 dry Scales
Not considered: oily sludges
NORM residues
Red Mud from the extraction of bauxite
P4.1 Red mud Lauta P4.2 Red mud AOS Stade
NORM residues
Tailings from the extraction of Uranium
P5.1, P5.3 & P5.4 silt-dominated Tailings
P5.2 sand-dominated Tailings
5 cm
5 cm
5 cm
5 cm
P5.1
P5.3 P5.4
P5.2
NORM residues
Residues of water treatment facilities
P6.1, P6.3, P6.6 & P6.7 different filter gravel
P6.9 Filtrolite
P6.11 powdered immobilisate (mine water clean up from former uranium mining)
ResultsActivityconcentration normalised to porevolume
1E-06
1E-05
1E-04
1E-03
1E-02
1E-01
1E+00N
i-sla
g
Cu-
slag
sand
y tin
ore
resi
due
cast
ing
cind
er
phos
phat
e sl
ag
Thei
sens
ludg
e
furn
ace
gas
slud
ge 1
sint
er d
ust 1
furn
ace
gas
slud
ge 2
sint
er d
ust 2
dem
. res
idue
1
dem
. res
idue
2
dem
. res
idue
3
dem
. res
idue
4
scal
e 1
scal
e 2
red
mud
1
red
mud
2
tailin
g 1
tailin
g 2
tailin
g 3
tailin
g 4
ww
-filte
r gra
vel 1
ww
-filte
r gra
vel 2
ww
-filte
r gra
vel 3
ww
-filte
r gra
vel 4
filtro
lite
Imm
obilis
at 2
ai PV (m
Bq/
l)
U-238 (1+10)U-238 (ph-stat)U-238 (SSE)U-238 (1+2)
Results
1E-06
1E-05
1E-04
1E-03
1E-02
1E-01
1E+00N
i-sla
g
Cu-
slag
sand
y tin
ore
resi
due
cast
ing
cind
erph
osph
ate
slag
Thei
sens
ludg
efu
rnac
e ga
ssl
udge
1si
nter
dus
t 1fu
rnac
e ga
ssl
udge
2si
nter
dus
t 2de
m. r
esid
ue1
dem
. res
idue
2de
m. r
esid
ue3
dem
. res
idue
4 scal
e 1
scal
e 2
red
mud
1
red
mud
2
tailin
g 1
tailin
g 2
tailin
g 3
tailin
g 4
ww
-filte
rgr
avel
1w
w-fi
lter
grav
el 2
ww
-filte
rgr
avel
3w
w-fi
lter
grav
el 4
filtro
lite
Imm
obilis
at 2
ai PV (m
Bq/
l)
Ra-226 (1+10)Ra-226 (ph-stat)Ra-226 (SSE)Ra-226 (1+2)
Activityconcentration normalised to porevolume
ResultsActivityconcentration normalised to porevolume
1E-06
1E-05
1E-04
1E-03
1E-02
1E-01
1E+00N
i-sla
g
Cu-
slag
phos
phat
e sl
ag
Thei
sen
slud
ge
furn
ace
gas
slud
ge
sint
er d
ust
dem
. res
idue
1
dem
. res
idue
2
scal
e
red
mud
1
tailin
g 1
tailin
g 2
tailin
g 3
wat
er w
ork
filter
gra
vel 1
wat
er w
ork
filter
gra
vel 2
wat
er w
ork
filter
gra
vel 3
ai PV (m
Bq/
l)
Pb-210 (1+10)Pb-210 (ph-stat)Pb-210 (SSE)Pb-210 (1+2)