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Hungarian Uranium Legacy Sites
Monitoring after closure
László JuhászNational Research Institute for Radiobiology and Radiohygiene
2
Brief history In the south part of Hungary, near Pécs city the
uranium was produced from a low grade underground sandstone ore (about 0.1 % U).
Besides mining activities, both the acid leaching process and the alkaline heap leaching technology were applied in the mill operation.
After 40 years operation the uranium mining and milling facilities were finally shut down in 1997.
Planning, surveying and making appropriate strategy for restoration tasks were launched in 1990’s.
There was no foundation, government has given budget for the remediation started in 1998.
The remediation was terminated in 2008
3
Uranium mining and milling area
4
Employees and uranium production
Employees And Uranium Output Between 1956-1997.
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
19
56
.
19
58
.
19
60
.
19
62
.
19
64
.
19
66
.
19
68
.
19
70
.
19
72
.
19
74
.
19
76
.
19
78
.
19
80
.
19
82
.
19
84
.
19
86
.
19
88
.
19
90
.
19
92
.
19
94
.
19
97
.
Year
Em
plo
yees
0
100
200
300
400
500
600
700
800
Meta
ll i
n T
on
ne
Employees
Uranium in tons
5
The most important radiation sources of uranium
mining and milling activity
Transportation roads and pipelines
Milling facility area
400 000 m2
Waste rock piles
900 000 m2 25 million tons
Leaching heaps
470 000 m2 7.2 million tons
Tailings ponds
1 630 000 m2 20.4 million tons
Total affected area 62 ha
6
Main authorities
- competent Inspectorate for Mining is responsible for aspectsrelating to mining activities, mining technology, mining safetyand geology, as well as remediation.
- competent Inspectorate for Environment, Nature and Waterenforces aspects relating to environment protection, natureconservation, protection of water quality, water utilisation andprotection of water bases
- competent Health Authorithy (Radiological Center) isresponsible for the radiation protection of workers and thepublic
7
Licensing of uranium mining and
milling
•Lack of national legislation in 1990’s: negotiations between
authorities and operator on licensing conditions
•First licence in 1998 (amended in 2002, 2004, 2007, 2009, 2011
and 2012) granted by the competent regional environmental
authority including radiation protection prescriptions
• No foundation: Governmental Resolution Budget
• Modified governmental budget and deadlines:
2193/2004: 18,5 → 19,1 billion HUF new deadline: 31. 12. 2006
2122/2006: 19,1 → 20,7 billion HUF new deadline: 31. 12. 2008
8
The most important radiation sources of uranium
mining and milling activity
Transportation roads and pipelines
Milling facility area
400 000 m2
Waste rock piles
900 000 m2 25 million tons
Leaching heaps
470 000 m2 7.2 million tons
Tailings ponds
1 630 000 m2 20.4 million tons
Total affected area 62 ha
Radionuclide inventory at Pécs
uranium mining and milling site
Radionuclide
Activity in Bq
Waste
rock
Tailings
pond
Heap
leaching
U-238 1,26 E13 1,69 E13 4,61 E12
U-235 5,9 E11 7,94 E11 2,26 E11
Ra-226 1,26 E13 2,34 E14 1,14 E13
Pb-210 1,26 E13 2,32 E14 1,15 E13
Total activity 1,8 E14 2,4 E15 1,4 E14
10
Ranges of main radiological parameters
Parameter W-Mecsek
areas
Waste
rock
piles
Heap
leaching
areas
Tailing
ponds
Unit
Ambient
gamma dose
rate
150-250 200-1000 1100-1500 200-3000 nGy/h
Rn-222
act. conc.
8-12 10-50 10-50 40-1100 Bq/m3
Rn-222
exhalation
rate
0.02-0.06 0.1-0.5 0.5-1 2-10 Bq/m2s
Ueq
concentration
of rock
3-5 50-100 50-200 50-150 g/t
Usage of restored area Release of a given area without any restriction is only possible
if the radiation levels have been decreased to the original
background conditions.
Release of an area for restricted use is possible if the
radioactive levels were decreased until that the radiation dose
of public/workers falls below 1 mSv/year effective dose limit.
Restricted use means the exclusion of food production and
building human residences, schools, hospitals, etc. Industrial
and marketing activity can be performed, using the still
existing/reconstructed infrastructure.
The restoration was planned to reach to this situation.
12
Landscape before and after remediation
Shaft
13
Landscape before and after remediation
Milling site
Dose rate before and after remediation
14
2 540 000 compact m3 + 44 300 m3
1 070 000 compact m3 + 34 732 m3
Relocation and remediation
of heap leaching sites
15
1994. NOV.12 melléklet
1995. SZEPT.12 melléklet
(nGy/ h)
After remediation of
waste rock pile 3
Dose rate before and after remediation
of waste rock pile 3
16
After remediation
of tailings pond 1
After remediation of
tailings pond 2
17
Reference background levels
Radioactive
parameter
In all areas
222Rn
concentration
outdoors
12 Bq/m3
222Rn
concentration
indoors
128 Bq/m3
Ambient gamma
dose rate
250 nGy/h
Activity
concentration of
soil*
180 Bq/kg
Remarks: *Expressed in 226Ra equivalent
Radiation protection criteria after closure 1a
Requirements for restored places:
Parameters Values
Rn flux < 0.74 Bq/m2/s
Gamma dose rate* ≤ 250 nGy/h
Remarks: * average value, it should not exceed above 450 nGy/h
Radiation protection criteria after closure 1b
soil disturbance is prohibited
grass, pasture field are permitted
production of foodstuff for people prohibited
human residences; recreation, sport, social
facilities; schools, hospitals not permitted
Radiation protection criteria after closure 2a
Reuse of facilities (buildings), operational area, roads,
neighbour area (not belong to mining area):
Parameter Value
Gamma dose rate* ≤ 250 nGy/h
Remarks: * average value, it should not exceed above 450 nGy/h
Radiation protection criteria after closure 2b
Before any usage of operational area
radiological expert opinion is needed
During soil disturbance radiological control
and monitoring should be performed
After any disturbance activity background
levels should be set back
Radiation protection criteria after closure 3
Limit for contamination of groundwater:
Radionuclides Limit
Nat U 0.4 mg/m3
Ra-226 0.63 mg/m3
Radionuclide Liquid discharge Airborne discharge
Ra-226 7.4 E9 -
U-234 1.1 E11 9.1 E8
U-235 1.1 E11 9.6 E8
U-238 1.1 E11 2.4 E6
Annual discharge limits from restored area (Bq)
Radiation protection criteria after closure 4
Dose constraint for the restored area: 300 µSv/a
Radiation protection criteria after closure 5
Metalic waste*
general use without restriction < 0.05 Bq/cm² (3 alpha particles/cm²/m)
metallurgical or mining re-use 0.05-0.5 Bq/cm²
emplacemet in waste rock pile 3 >0.5 Bq/cm² (30 alpha particles/cm²/m)
Other waste materials (debris, sludge, wood, rubber,…):
handling as normal waste ≤ 200 Bq/kg
emplacemet in waste rock pile 3 > 200 Bq/kg
Release of materials:
Remark: * only for fix contamination
Chromium 50
Cobalt 20
Nickel 20
Copper 200
Zinc 200
Arsenic 10
Molybdenium 20
Selenium 10
Cadmium 5
Tin 10
Barium 700
Mercury 1
Lead 10
Boron 500
Silver 10
Limit for metal and semimetal contamination in groundwater (µg/l)
Fluoride mg/l 1500
Sulfate mg/l 250
Phosphate (PO43-) mg/l 500
Nitrate mg/l 50
Ammonium mg/l 500
Limits for inorganic compound contamination in
groundwater (µg/l or mg/l)
Chromium 75
Cobalt 30
Nickel 40
Copper 75
Zinc 200
Arsenic 15
Selenium 1
Molybdenium 7
Cadmium 1
Tin 30
Barium 250
Mercury 0,5
Lead 100
Silver 2
Limits for metal and semimetal contamination in soil (mg/kg)
Long-term tasks
removal of uranium from surface and groundwater (the
capacity of the water treatment station is 1.5 million m3
annually);
groundwater desalination (treatment of an average water
volume of 2000 m3/day);
maintenance of water treatment stations, decontamination
and water discharging systems;
operation of the unified water discharge system;
maintenance and after-care of areas of limited utilisation;
operation of environmental monitoring system
Monitoring after closure
Environmental monitoring system consits of:
• Hydrogeological
• Radiological
• Rock, soil movement survey
Each monitoring is to be performed on the
basis of annual plan.
Environmental monitoring program after
closure was prescribed in environmental
licence decision
Radiological monitoring
In situ measurements
Sampling on site
Measurements in laboratory
Continuous monitoring stations
In situ measurements
Gamma dose rate: in mesh points of 20mx20m, 50mx50m
above 1m of surface, detection 10 nSv/h-
Air 222Rn concentration: detection 1 Bq/m³ -
Air short lived radioactivity: determination of radon
progenies, detection 1 Bq/m³ - from 1 m³ air
Integral air 222Rn concentration: SSNTD, exposure time 3
months, detection ~Bq/m³ -
Fallout: collection of precipitation during 3 months
Aerosol, flying dust: detection <0.1 mg/ m³- from ~10 m³ air
Soil radioactivity in depth by 20 cm: gamma probe,
detection ~50Bq/kg
Soil surface 222Rn exhalation: radon accummulated in semi
cylinder, detection ~mBq/m² s -
Sampling
Soil sampling: taking representative soil
sample (~ 1kg) from 1m² in depth of 10 cm
Plant sampling: taking ~1kg plant sample
Water sampling: taking water sample from
flooded mines, streams, groundwaters
(monitoring wells) and surface waters
Measurements in laboratory 1
Air long lived alpha radioactivity: determination from
aerosol filter sample, detection ~ mBq/m³
Soil Ra-226 equivalent activity concentration: high
sensitivity scintillation detector, detection from 40 keV
Soil gamma spectrometry: semi conductor detector
(HPGe), measure time 10000-50000 s, detection 1 Bq/kg
Plant ash beta activity concentration: high sensitivity
alpha/beta detector, measure time 1000-3600 s
Plant ash gamma spectrometry: semi conductor detector
(HPGe), measure time 50000-100000 s, detection 1 Bq/kg
Measurements in laboratory 2
Water natural U content: determinated with ICP-MS ,
detection 0.05 µg/l
Water Ra-226 activity concentration: determined with liquid
scintillation, detection 0.1 Bq/l
Evaporated water beta activity concentration: low
background and high sensitivity alpha/beta detector,
detection 0.1 Bq
Water alpha spectrometry: determination of U-234, U-235,
U-238, Po-210 activity concentration: detection 1 mBq/l
Continuous monitoring stations 1
Complex radiation montoring station comprises: Ambient gamma dose rate: measurements by 1 hour, from 50
nSv/h
Istantaneous air Rn-222 activity-concentration: measurements
by 10 minutes, from 2 Bq/m³
Istantaneous air short lived radioactivity: determination of
radon progenies by 10 minutes, from 1 Bq/m³
Cotinuous air sampling by 1 m³/h
Temperature, pressure, relative humudity mesurements
Aerosol, flying dust concentration: filter measurements by 1
week, from 0.01 mg/ m³
Continuous monitoring stations 2
Air Rn-222 activity-concentration monitoring: Determination with PIPS detector by hour (together with climate
parameters)
Range: 0,1 kBq/m3 – 5 MBq/m3
Air release monitoring Cotinuous air sampling
Aerosol, flying dust concentration: filter measurements by 1
week, from 0.01 mg/ m³
Natural U content determination: filter measurements by 1 week,
low background and high sensitivity alpha/beta detector
Long term plan of restored tailings ponds and
waste rock piles
surveying gamma dose rate in mesh points in each 3 year
Cotrolling radon barriers: complex radon examination (act.
conc., exhalation, radon progenies) yearly, later 3-5 years
Radioniclide migration: vertical, horizontal by 3-5 years
38
Special requirements for radiation monitoring 1
Restored and operational area:
• at main outlet points continuous measurement of
radon must be performed
• integral radon measurements should be agreed with
radiological authority
• measurements of gamma dose rate in mesh points
should be carried out in each 5 year
Special requirements for radiation monitoring 2
Other area:
• all radiological parameter should be on background level,
monitoring is not needed
• activity concentration and uranium content of mud of
streams by 200 m should be determined
• measurements of gamma dose rate at banks of streams
by 10m must be performed in each 2 year
• gamma dose rate measurements of roads and curbs must
be surveyed, and at later works on roads radiological
control is needed
Surveyed remediatied
area
Rn
sesonal
Year Gamma
dose rate
Complex
radon
Soil
Plant Profile
No. of
sample
Waste rock pile 1.1/4 y
4 x 3 pcs
2014
(2017)
20x20 m
300 pcs
100x100 m
12 pcs
3 migr.vert.
2 migr.horiz.
(2015)
15 pcs
6 pcs9 pcs
Waste rock pile 2. 1/4 y
4x3 pcs
2014
(2017)
20x20 m
430 pcs
100x100 m
17 pcs
3 migr.vert.
2 migr.horiz.
(2015)
15 pcs
6 pcs9 pcs
Waste rock pile 3. 1/4 y
4x5 pcs
2014
(2017)
50x50 m
200 pcs
200x200 m
12 pcs
5 migr.vert.
2 migr.horiz.
(2016)
25 pcs
6 pcs11 pcs
Tailings pond 1.
1/4 y
4x5 pcs
2013
(2016)
50x50 m
420 pcs
200x200 m
26 pcs
5 migr.vert.
2 migr.horiz.
2013
35 pcs
6 pcs
11 pcs
Tailings pond 2.1/4 y
4x 5 pcs
2013
(2016)
50x50 m
240 pcs
200x200 m
15 pcs
5 migr. vert.
2 migr.horiz.
2014
35 pcs
6 pcs11 pcs
Waste rock pile 3A. 1/4 y
4x3 pcs
2013
(2016)
20x20 m
220 pcs
100x100 m
9 pcs
3 migr. vert.
1 migr.horiz,
2013
25 pcs
6 pcs11 pcs
Waste rock pile Frici
shaft
1/4y
4x 3 pcss
2013
(2016)
20x20 m
50 pcs
100x100 m
5 pcs
2 migr.vert.
l migr.horiz.
2013
15 pcs
6 pcs11 pcs
Surveyed operational area Year Soil Plant Air Complex
radon Gamma dose rate
Mine operational yard 2. 2013 (2016) 2 2 2 50x50 m 10x10 m 180 pcs
Mine operational yard 3. 2013 (2016) 2 2 2 50x50 m 10x10 m 240 pcs
Mine operational yard 1. 2013 (2016) 4 4 4 50x50 m 10x10 m 270 pcs
Surveyed outlet of mine
shaftRn monitoring
Complex air
measurements
SSNTD SSNTD
indoor outdoor
Mine transport shaft 1. continuous 6 pcs/y 6x4 pcs/y 6x4 pcs/y
Mine North shaftcontinuous
6 pcs/y 6x4 pcs/y 6x4 pcs/y
Surveyed water flow Frequency Activity concentration
of bed sediment
Gamma
dose ratePlant
Year No. of sample Mesh points Sample
Stream Zsid 2013
(2015) 5 pcs by 200 m
2x10m
170 pcs2 pcs
Stream Kajdács 2013
(2015) 18 pcs by 200 m
2x10m
700 pcs2 pcs
Canal Milling Facility 2013
(2015) 12 pcs by 200 m
2x10 m
440 pcs2 pcs
Canal Zóki 2013
(2015) 32 pcs by 200 m
2x10 m
1240 pcs2 pcs
Surveyed
dwellingsYear
Complex
air
Complex
radon Soil Plant
SSNTD SSNTD
indoor outdoor
Kővágószőlős 2013 (2015) 1 pc 1 pc 1 pc 1 pc .. 1x4 pcs/y 1x4 pcs/y
Pellérd 2013 (2015) 1 pc 1 pc 1 pc 1 pc 1x4 pcs/y 1x4 pcs/y
Surveyed area
Continuous
/Automatic
monitorlng
Fall-out
SSNTD SSNTD
indoor outdoor
Tailings ponds 1.
and 2.
1 pc radiation
monitoring3x4 pcs/y -- 6x4 pcs/y
Mine water treatment
facility
1 pc radiation
monitoring 1x4 pcs/y 8x4 pc/sy 4x4 pcs/y
Chemical water
treatment facility1 pc Rn monitoring
--2x4 pcs/y 2x4 pcs/y
Disposal of inert
waste -- 1x4 pcs/y -- 1x4 pcs/y
Loess mine -- 1x4 pcs/y -- --
Release point Release way Monitoring method Frequency
Mine water treatment
facility
2 pcs stack
air
Unat
continuous
sampling,
weekly
gross alpha activity
dust and aerosol
Discharge from Frici
shaft to sidestream of
stream Bicsérd
water Complex water
examinationhalf year
Discharge to stream
Pécsi-VÍz (one point)water
Complex water
examination quaterly
Surveyed groundwater area Object
(pcs)
Measure-
ment of
water
level
Water
samplnig
Radio-
logical
meas-
urement
Full scale
water
exami-
nation
Partial
scale
water
exami-
nation
Trace
element
exami-
nation
North mine facilities 91 91 91 91 91 0 0
Waste rock pile 1. and 3.
(drills) 27 108 65 65 34 17 5
Heap leaching field 2, waste rock
pile 2. 57 164 164 89 75 5
Waste rock pile 3., inert waste
disposal31 101 101 49 52 10
Migration barrier at waste rock
pile 3.33 78 78 25 31 34
Tailings ponds (1., 2.) 159 545 62 154 394 19
Wells of water supplying area at
Pellérd and Tortyogó44 79 79 57 20 58
Digged wells at Cserkút 3 4 4 1 2 4 1
Digged wells at Kővágószőlős 7 7 7 7 3 7 3
Surveyed spring (outlet) and surface
water
Object
(pcs)
Water
samplnig
Radio-
logical
meas-
urement
Full
scale
water
exami-
nation
Partial
scale
water
exami-
nation
Trace
element
exami-
nation
WRP 2., Frici shaft, stream Bicsérdi 29 92 92 24 40 7
Waste rock pile of air-shaft 4, 1 4 4 2 2 1
Waste rock pile 4. of shaft 4. 1 1 1 1 1
Air-shaft Tótvár 1 1 1 1 1
Waste rock pile of air-shaft 5. 1 1 1 1 1
Waste rock pile of shaft 5. 1 1 1 1 1
Heap leaching field 2, WRP 1. (ditch) 5 9 9 4 4 2
Tailings pond 1. 4 16 16 4 12 4
Tailings pond 2. 4 16 16 4 12 4
Seepage water of tailings ponds 8 32 32 8 24 8
Mine water release (monitoring point) 6 32 32 14 18 7
Stream Rékás 3 6 6 6
Stream Kaidács 2 4 4 4
Stream Zsid 2 4 4 4
Stream Névtelen 2 4 4 4
Periphery site 2 2 2 2
Canal Zóki 3 6 6 6
Stream Pécsi-víz 6 20 20 8 12
Stream Sás 3 6 6 3 3
Stream and spring Nyáras 2 6 6 3 3 1
Stream Körtvélyes 2 4 4 2 2
577000 577500 578000 578500 579000 579500 580000 580500 581000 581500 582000
74500
75000
75500
76000
76500
77000
77500
78000
Zagytér kelet
Zagytér vízkezelő
Pellérd lakossági
Pellérd
I.
II.
A zagytározók és környékük radiológiai monitoring állomásai
Á: Monitoring állomás Hullópor gyûjtõ állomás
Löszbánya
Geotechnika konténer
Location of monitoring stations at tailings ponds
Á: automatic minitoring station Fall-out collection station
Gamma dose rate
Soil Water Air Biosphere
Radiology(U, Ra, Th, g-
dose)
Chemical
Pollution,(CH, acid,
trace elements)
Erosion
Movement
Environmental Monitoring System
Radiology(U, Ra)
Chemical
Pollution,(anorganic, CH,
trace elements)
Water level
Water quantity
Radiologyaerosol
fallout
radon
Vegetation(radiologic
elements)
Humandosimetry
(labour
hygiene)
Location of monitoring
sampling points
IAEA per review 1
IAEA peer review in December 2010, main findings:
• Risk of pollution of surface waters has been decreased,
• Facilities for water treatment are in a good function,
• For protection of aquifers, water treatment shall be
performed for few decades,
• Monitoring program is in line with the expectations of
IAEA.
IAEA per review 2
Main recommendations:
- Long-term (30 years) strategic plan should be elaborated,
It’s accomplished
- Review of modeling should be performed for rank of layers of
tailings ponds,
It’s close to accomplished
- Erosion damages should be repaired,
The repairs are being continually performed
- Infiltration parameters for waste rock piles should be reviewed,
- On tailings ponds 2 new lysimeter were installed, but on rock
piles not yet
- Gas migration from mine cavities should be thoroughly examined,
- The examination of gas migration is being continually
performed under monitoring programme
IAEA per review 3
- Groundwater and polluted water transport model should be set
up,
It’s completed
- Passive methods for water treatment should be preferred,
Passive methods are preferred at present and in the future
- New equipment for monitoring and new damage averting plan
are needed,
It’s continually set up
- Uniformity of emission limits based on risk analysis should be
set off,
Authorities have accepted limitation on risk analysis in
many cases
Conclusions
Exact and updated radiation data: essential
basis after closure
Radiation protection criteria system should be
based on comprehensive background database
Modelling, studies and other R&D works are
needed for selection of suitable monitoring
program after closure
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