Environmental Attributes of Mining and Processing

of Uranium Ore in Singhbhum, Jharkhand, India

V.N. JHA HEALTH PHYSICS UNIT, JADUGUDA

HEALTH PHYSICS Division Bhabha Atomic Research Centre

Trombay, Mumbai – 400 085 Email : jhavn1971@gmail.com

Tel. : +91-22-2559 5415 +91-657-2731231 Fax : +91-657-2730 322

12/11/2015

Mines 1. Jaduguda

2. Narwapahar

3. Bhatin

4. Turamdih

5. Banduhurang (O/C)

6. Bagjata

7. Mohuldih (development)

Ore Processing Plants 1. Jaduguda Mill

2. Turamdih Mill

Tailings Ponds 1. Three Numbers of Tailings Pond at Jaduguda

2. OneTailings pond at Turamdih

Ore Mining

Crushing and Grinding

Leaching and Filtration

Ion Exchange

Hydro cyclone

Precipitation and Drying

Yellow cake (MDU)

Transported to NFC (Hyderabad, A.P)

Coarse Fine

Mine back

filling

TP

ETP

Local

Discharge

Hydrometallurgical process

BarrenLiquor

BarrenCake

FLOW SHEET FOR URANIUM ORE PROCESSING

Radiological Concern of Environment Around Uranium Mines

Release of gaseous 222Rn and progeny

Long-lived alpha active dust

Mine water containing dissolved radionuclides

Overburden and waste rock

Radiological Concern of Environment Around Uranium Mill

Tailings disposal

Effluent discharges

Gaseous releases

Radioactive Features of Mill Tailings

The milling of uranium ore removes ~ 90% uranium Tailings contain all the decay products of U-238 and U-235 series The radioactivity of uranium tailings controlled by three principal radionuclides - Th-234 (half-life (t½ - 24.1 days) Th-230 (t½ - 80,000 years) Ra-226 (t1/2 - 1600 years) and Residual uranium (U-238, t½ - 4.51 billion years; U-235 t½ - 710 million years)

ENVIRONMENTAL CONCERN OF URANIUM MILL

TAILINGS

1. They retain much of the radioactivity of the concerned ore

2. Their radioactivity is long lived 3. Their granular to slime consistency makes them

susceptible to leaching, erosion or collapse under various conditions

4. A large surface area to the natural elements and thus increases the risk of release of radiation flux, radioactive and geochemically toxic dusts

5. Interaction with surface water/ ground water systems

POTENTIAL HAZARDS FROM URANIUM MILL TAILINGS

At JADUGUDA - three valley-dam type of tailings ponds One operational Two Saturated to Filled capacity

At Turamdih – One tailings ponds operating

In all the four tailings pond neutral solid is retained and liquid effluent is allowed to drained for further treatment prior to disposal

Sampling map of Jaduguda

2

4

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1

11

Monitoring - Why?

• Monitoring provides the basis to demonstrate compliance with the regulatory requirements.

• Monitoring and surveillance are vital tools in confirming that

operations and facilities are performing as expected.

Facilities and releases

Pathways & transfer in environment

Regulatory requirements

Detection Basics

Monitoring strategy

Inputs of monitoring

Monitoring objectives

To gather data related to sources of human

exposure in the area

Evaluation of radiological status of the environment

Assessment of radiation exposure to members of the

public

Ensure adequacy of control measures / Evaluation

of regulatory compliance

Develop suitable protocols & techniques to carry out

the Environmental Surveillance Programme

Occupational

Monitoring

Environmental

Environmental Routine Monitoring Matrix Parameters

Effluent U, 226Ra, Conventional

Surface water -do-

Ground water -do-

Monitoring wells (TP) -do-

Soil U, 226Ra, 230Th, 210PO

Sediment -do-

Vegetables -do-

Seepage & overflow -do-

External gamma radiation survey

Measurement of 222Rn & its progeny concentration in

atmosphere

DOSE RATES ON THE TAILINGS SURFACE

•The gamma radiation dose rates 1m directly

above the tailings pile range from about 0.75–3.3 uGy h-1, averaging around 1 uGy h-1

• This reduces to about 0.2 - 0.5 uGy h-1 on the

embankment Note: Normal background level 0.10-0.20 µGy.h-1

(10-15 µR.h-1)

Sample collection & preparation:

Effluent, Surface water and ground water

i. Grab samples are collected from inlet and outlet of

ETP, Surface water from upstream and

downstream with respect to discharge (Juria/Gara

and Suvernrekha river)

ii. Ground water samples are collected from wells

and tube wells from areas near tailings pond and

away.

iii. Samples are filtered immediately after collection

and preserved in conc.HNO3 (1 ml/l)

Analytical procedure U (nat)- Solvent extraction in alamine benzene solvent, fusion of organic layer with Na2CO3

: NaF (85:15), Fluorimetry, comparison with standard. Uranium evaluated from sample reading, blank reading and sampling parameters

226Ra- Concentrated water, effluent or digested aliquot loaded in

emanometric set up. In built radon removed, left for fresh build up of radon. Radon collected in evacuated Scintillation cell, left for 200 min to ensure equilibrium, alpha counted. 226Ra determined from build up, delay, efficiency and sampling parameters

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Average Natural Background in Different States of India

Atmospheric radon levels are periodically

measured adjoining the mining, ore processing

and tailings management facilities of Singhbhum.

Distance away from the facilities is also

periodically monitored for atmospheric radon. The

average radon concentrations around Bagjata

mining region was 28 ± 11 Bq m-3, around

Jaduguda 35 ± 7, Narwapahar are 25 ± 9 and

Turamdih around 25 ± 5 Bqm-3, respectively.

•The effectiveness of the effluent treatment plant in

controlling the release of radioactive materials to the

aquatic environment is evaluated by measurement of

U(nat.) and 226Ra in the inlet and outlet effluents.

Effluent and Surface water

Concentration of U(nat) in treated effluent at Jaduguda

was ranging from 1.2 to 7.7 mg l-1 with median

concentration of 2.7 mg l-1 and 226Ra concentration was

ranging from 3.5 to 176 mBq l-1 with median concentration

of 4 mBq l-1.

The U(nat.) and 226Ra concentrations observed in the

surface waters of nearby river of Jaduguda was found to

vary from 2.2 – 55 mg l-1 and 3.6–45 mBq l-1 with median

concentration of 7.8 mg l-1 and 10. 5 mBq l-1 respectively.

The U(nat.) and 226Ra concentrations observed in the

surface waters of nearby stream of Turamdih was found

to vary from 2.2 – 16 mg l-1 and 4 –20 mBq l-1 with median

concentration of 9.1 mg l-1 and 7 mBq l-1 respectively.

Natural Radioactivity Levels in Soil

Distance from the

facility (km)

N

U(nat)

mg kg-1

226Ra

Bq kg-1

Jaduguda

0.5 5 2.8 25

0.5-1.6 4 2.6 35

1.6-5 4 2.1 44

5-10.0 4 3.3 53

>10 3 1.9 42

Turamdih

< 1.6 20 1.5 23

1.6 – 5 24 1.7 31

5 -10 16 1.8 36

Narwaphar

< 0.5 4 1.1 23.4

0.5-1.6 4 1.3 35.5

1.6-5 8 1.4 39

5-10 10 1.6 41

Bagjata

0.5 5 2 52

0.5 – 1.6 4 3.6 89

1.6-5 4 3.1 47

5-10 4 2.9 60

> 10 3 2.2 57

Median concentration of radionuclide in monitoring well around tailings pond

Monitoring Well No.

(Jaduguda)

U(nat)

mg l-1

226Ra

mBq l-1

1 1.6 60

2 1.9 33

3 2.7 29

4 1.9 21

5 2.2 10

6 3.2 10

7 1.7 19.5

DWC Limit 60 300

Monitoring Well

No. (Turamdih)

U(nat)

mg l-1

226Ra

mBq l-1

1 1.1 9

2 0.9 11

3 3.2 10

4 1.4 18

5 0.8 11

6 2.1 26

7 4.3 17

8 1.1 25 DWC Limit

60 300

Median concentration of radionuclide in monitoring well around tailings pond

Distance from TP

(kms)

N

25th 50th 75th

0-0.5 101 0.5 0.91 2.1

0.5 – 1.6 167 0.5 1.4 3.6

1.6 – 5 97 0.5 0.8 2.7

5 -10 129 0.5 0.6 2.0

Percentile distribution of uranium (mg l-1) in ground water at

different distances from tailings pond

Distance from TP

(kms)

N

25th 50th 75th

0-0.5 101 3.5 8.9 77 0.5 – 1.6 167 3.5 6.5 15.3 1.6 – 5 97 3.5 8.2 21.8 5 -10 129 3.5 6.8 18.6

Percentile distribution of 226Ra (mBq l-1) in ground water at different

distances from tailings pond

Distance from the

facility

N

U(nat)

mg kg-1

226Ra

Bq kg-1

Jaduguda

0.5 5 2.8 25

0.5-1.6 4 2.6 35

1.6-5 4 2.1 44

5-10.0 4 3.3 53

>10 3 1.9 42

Turamdih

< 1.6 20 1.5 23

1.6 - 5 24 1.7 31

5 -10 16 1.8 36

Narwaphar

< 0.5 4 1.1 23.4

0.5-1.6 4 1.3 35.5

Activity Concentration of Radionuclide in soil around uranium

mining and ore processing facility (2013-14)

Narwapahar

1.6-5 8 1.4 39

5-10 10 1.6 41

Bagjata

0.5 5 2 52

0.5 – 1.6 4 3.6 89

1.6-5 4 3.1 47

5-10 4 2.9 60

> 10 3 2.2 57

Activity Concentration of Radionuclide in soil around uranium

mining and ore processing facility (2013-14)

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Inh

ala

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ose (

mS

v/y

) Annual dose due to radon (outdoor) to the public (mSv/y) around uranium Tailings Pond (TP), Jaduguda

0 km

20 km 5 km

50 m 500 m

1 km 1.5 km

2 km 3 km 10 km

Particulate dust (LLα)

Low grade ore and tailings have negligible contribution

Long-lived radioactivity from ore and tailings dust is

significant only for ores grades above 1 % U3O8

Control measures of water spray and dust extraction at

the mine and mill sites and proper soil and vegetation

cover over the waste rocks and tailings surfaces will

reduce the generation and dispersal of dust

RADIATION EXPOSURE PATHWAYS RADIATION

SOURCE

AIR WATER

SOIL SAND &

SEDIMENTS

ANIMALS PLANTS

MILK MEAT

AQUATIC

ANIMALS

AQUATIC

PLANTS

FISHING

GEAR

HUMAN

Public Dose Evaluation

Integrated gamma (Environmental TLD),

Gamma survey, occupancy factor

Inhalation dose 222Rn progeny concentration

(Indoor and Outdoor) occupancy and

integrated passive radon cup type dosimeter

Internal exposure

Radionuclides in dietary components

Consumption data (National average or

dietary survey)

Total dose = External gamma + Inhalation +

Ingestion

Uranium mining activities in the Singhbhum region of Jharkhand state, India have been carried out for the last five decades.

Study reveal that the radioactivity and radiation dose to members of the public residing around the uranium mining complex is comparable to other regions of the world.

Baseline studies and comparison: Baseline studies

incorporating radiological, non-radiological, health, demographic,

hydrogeological, biodiversity concerns. A closer look of the

radiological component of baseline studies at Bagjata and

Turamdih reveal the fact that almost after a decade operation has

not altered the exposure pattern of the population residing around

these areas.

Non-radiological attributes of the environment: Heavy

metal content in diverse matrices, suspended and

respirable particulate matter in the air, SOx, NOx in air,

anions in drinking water, basic water quality parameters in

treated effluent, surface water and ground water.

RULES APPLICABLE TO URANIUM MINING AND MILLING

ATOMIC ENERGY ACT, 1962.

• RADIATION PROTECTION RULES, 1971.

• NOTIFICATION DATED 15.03.1995 RELATING TO

PRESCRIBED SUBSTANCES

3. ATOMIC ENERGY (WORKING OF THE MINES, MINERALS

AND HAHDLING OF THE PRESCRIBED SUBSTANCES),

RULES 1984.

4. ATOMIC ENERGY (SAFE DISPOSAL OF RADIOACTIVE

WASTES) RULES, 1987.

5. Public and Community participation

THESE ARE IN ADDITION TO RELEVANT RULES AND

REGULATIONS FRAMED UNDER MINES AS WELL AS

ENVIRONMENTAL POLLUTION CONTROL ACTS.

Conclusion The state of art technology adopted by uranium mining and

processing industry of India and regular surveillance/

monitoring ensure environmental supportive operations of

the facilities. Regular discharges of tailings nearly for five

decades around Jaduguda and a decade around Turamdih

did not alter the pre existing status of the radiological

environment. The surveillance & monitoring capabilities of

the expert and community participation in achieving the

environmental protection targets is anticipated to ensure

sustainability of the industry for decades.