NORM and NARM

Report
NORM and NARM
Content Partially Based on Lecture Materials from Dr. John Poston.
Radioactive Waste Management and
Disposal
NUCP 1311
Objectives
• Define NORM and NARM wastes
• Discuss sources of these wastes, generation
rates, and total activities of each
• Look at one process as an example of man’s
activities
Comment
• It is sometimes very difficult to define the
dividing line between materials that
contribute to the “technologically-enhanced
natural radiation environment” (TENRE) and
the wastes classified as NORM and NARM
TENRE
• “…. exposures to truly natural sources of
radioactivity which would not occur without
(or are increased by) some technological
activity not expressly designed to produce
radiation.”
UNSCEAR
http://www.unscear.org/unscear/index.html
NORM
• Naturally Occurring Radioactive Material –
materials not covered in the Atomic Energy
Act whose radioactivity has been enhanced
(i.e., materials whose radionuclide
concentrations are either increased or
redistributed compared to typical background
levels either naturally or as the result of
human intervention or processes).
NARM
• Naturally occurring or Accelerator produced
Radioactive Material – any radioactive
material that can be considered naturally
occurring and is not source, special nuclear, or
by product material, or it is a radioactive
material produced in a charged particle
accelerator.
Naturally Occurring Radioactive
Material (NORM)
• Results from the concentration of naturally
occurring radionuclides found in the earth’s
crust
• Classified as:
– Discrete wastes
– Diffuse wastes
NORM
• Discrete wastes have relatively small volumes
but large radioactivity
– Industrial gauges
– Radium watches and clocks
– Radium needles (medical applications)
– Resins to remove radium and other NORM from
ground water
NORM
• Diffuse wastes have relatively large volumes
but small radioactivity
– Coal ash and slag
– Solid wastes from geothermal activities
– Wastes from mining and processing for other
metals (e.g., copper)
– Sludge from drinking water treatment
– Scale, etc. from oil and gas production
– Wastes from mining phosphate ores
U-235 Chain
Th-232 Chain
Consumer Products
•
•
•
•
•
•
Radioluminous products
Electronic and electrical devices
Antistatic devices
Smoke and fire detectors
Ceramics and U-Th alloys
Other products, i.e., scientific instruments
Discrete Wastes
• Radium dial watches:
0.1 – 3 Ci
• Instrument dials:
~ 20 Ci
• In 1977, ~ 8.4 million radium-bearing
timepieces were in use in the U.S.
• According to UNSCEAR, radium dials have not
been manufactured since 1966
Diffuse NORM Wastes
• Major radionuclides include:
–
–
–
–
–
U-234, 235, 238
Th-228, 230, 232
Ra-224, 226, 228
Pa-231, Ac-227, Rn-222
Po-210, Pb-210, K-40
• Annual generation rate – 1.1 x 109 tons/y
• Total mass - 60 x 109 tons*
• Total activity - ~ 5 x 106 Ci*
* Represents the total inventory
Combustion of Coal
• Contains U, Th, Ra, and their daughter products
as well as 14C
• Products of combustion are called “bottom ash,”
“boiler slag,” and “fly ash”
• Consists mostly of Al, Fe, Ca, and Si
• Concentrations in coal vary with mining location
and region
– Coal in western states (Wyoming, Idaho and Montana)
contains much higher concentrations of uranium
– Concentrations several hundred ppm compared to 10
ppm in eastern coal
Diffuse NORM Wastes
• Radionuclides found in coal combustion
wastes:
– U-234, 235, 238, Pa-231, Ac-227, Po-210
– Th-228, 230, 232, Ra-226, 228, Pb-210
– Concentration in fly ash ~ 27 pCi/g
– Concentration in slag ~7 pCi/g
Coal Combustion Wastes
• Annual generation rate
– Bottom ash & slag
– Fly ash
17 x 106 tons/y
44 x 106 tons/y
• Total mass
– Bottom ash & slag
– Fly ash
340 x 106 tons
960 x 106 tons
• Total activity
– Bottom ash & slag
– Fly ash
2,300 Ci
26,000 Ci
NORM and NARM – II
or is it NARM and NORM?
Content Partially Based on Lecture Materials from Dr. John Poston.
Official Definitions (EPA Website)
• By-product Material
– There are basically two types of by-product
materials.
• The first are produced by a nuclear reactor
• The second are produced by the uranium and thorium
mining process.
– A more precise definition reads:
"(1) Any radioactive material (except special
nuclear material) yielded in, or made radioactive
by, exposure incident to the process of producing
or utilizing special nuclear material, and (2) The
tailings or wastes produced by the extraction or
concentration of uranium or thorium from ore
processed
primarily for its source material
http://www.epa.gov/radiation/mixed-waste/mw_pg5.htm
content, including discrete surface wastes
Official Definitions (EPA Website)
• Source Material
– Source Material is the Uranium or Thorium ores
mined from the Earth.
– Source material is defined in 10 CFR 20.1003 as
"(1) Uranium, or thorium or any combination of
uranium and thorium in any physical or chemical
form; or (2) Ores that contain, by weight, onetwentieth of 1 percent (0.05 percent), or more, of
uranium, thorium, or any combination or uranium
and thorium. Source material does not include
special
nuclear material."
http://www.epa.gov/radiation/mixed-waste/mw_pg5.htm
Official Definitions (EPA Website)
• Special Nuclear Material (SNM)
– SNM is defined in 10 CFR 20.1003 as
"(1) Plutonium, uranium-233, uranium enriched in
the isotope 233 or in isotope 235, and any other
material that the NRC, pursuant to the provisions
of section 51 of the AEA, determines to be SNM,
but does not include source material; (2) or any
material artificially enriched by any of the
foregoing but does not include source material.“
– SNM
is important in the fabrication of weapons
http://www.epa.gov/radiation/mixed-waste/mw_pg5.htm
Official Definitions (EPA Website)
• Naturally Occuring or Accelerator Produced Radioactive
Materials (NARM)
– Radioactive materials not covered under the AEA
that are naturally occurring or produced by an
accelerator.
– Accerlerators are used in sub-atomic particle
physics research. These materials have been
traditionally regulated by States.
– A subset of NARM is NORM. NARM waste with
more than 2 nCi/g of 226Ra or equivalent is
commonly referred to as discrete NARM waste;
below
this threshold, the waste is referred to as
http://www.epa.gov/radiation/mixed-waste/mw_pg5.htm
diffuse NARM waste.
NARM Radionuclides
• About 50 radionuclides found in NARM.
• Range from 11C to 204Bi.
• Many radionuclides decay through - or +
emission or EC, and IT.
• Most have short half-lives (seconds, minutes,
days, hours), except for 81Kr (2.1 x 105 y).
NARM
• Wastes are generally not regulated by the
federal government.
• Responsibility rests with the states – part of
their authority to ensure protection of the
public health and safety.
• But, some states do not have regulatory
programs.
Official Definitions (EPA Website)
• Naturally Occurring Radioactive Materials (NORM)
– NORM is a subset of NARM and refers to materials
not covered under the AEA whose radioactivity
has been enhanced.
– Enhancement means that the radionuclide
concentrations are either increased or
redistributed where they are more likely to cause
exposure to man usually by mineral extraction or
processing activities.
– Examples are exploration and production wastes
from the oil and natural gas industry and
phosphate slag piles from the phosphate mining
industry.
– This
term is not used to describe or discuss the
http://www.epa.gov/radiation/mixed-waste/mw_pg5.htm
natural radioactivity of rocks and soils, or
NORM
• Naturally Occurring Radioactive Material –
materials not covered in the Atomic Energy
Act whose radioactivity has been enhanced
(i.e., materials whose radionuclide
concentrations are either increased or
redistributed compared to typical background
levels either naturally or as the result of
human intervention or processes).
Metal Mining & Processing
• Wastes include ore tailings and smelter slag (uranium
and phosphate wastes excluded).
• Typically contains U, Th, Ra and decay products.
• Some extraction processes yield waste with higher
radionuclide concentrations.
• Concentration varies with geologic formation and region.
NORM Wastes from Mining and
Processing
• Rare earth metals
– Lanthanide metals – 16 elements
• Special application metals
– Have unique commercial and industrial uses - Hf,
Sn, Ti, Zr
• Metals produced in bulk quantities
– Bulk industrial applications – Al, Cu, Fe, Pb, Zn, Au,
Ag
Wastes from Metal Mining and
Processing
• Generally, the same radionuclides are found in
the wastes from metal mining and processing
– Rare earth metals
– Special application metals
– Large-volume industry metals
11,000 pCi/g
305 pCi/g
74 pCi/g
• Large bulk metal industries (e.g., copper,
aluminum, iron, steel)
• Annual generation rate – 1 x 109 tons/y
• Total mass - 50 x 109 tons
6
Wastes from Metal Mining and Processing
•
•
•
•
Rare earths metals (Lanthanides)
Annual generation rate – 0.2 x 106 tons/y
Total mass - 1 x 106 tons
Total activity – 11,000 Ci
Municipal Water Treatment
• Some water supply systems treat water
containing elevated levels of NORM
• Radionuclides are leached into ground and
surface water
• Wastes include sludges and solids
– Filter sludges
– Ion-exchange resins
– Activated charcoal
– Radium-selective resins - discrete wastes
Diffuse NORM Wastes
• The same radionuclides are found in the
wastes from municipal water treatment
– Sludges
– Radium selective resins
~ 72 pCi/g
~ 35,000 pCi/g
Geothermal Energy Generation
• Using the natural
heat, pressure and
liquid from within the
earth
• Hot rock technology
also a potential source
of NORM
• Geysers, CA – Unit No.
18
Wastes from Geothermal Energy Production
• Minerals that precipitate out of solution forming scale or
sludge on the inside surfaces of equipment
• Contain barium, calcium, and strontium salts
(carbonates, sulfates, silicates) as well as silica
• Contain significant concentrations of radium and radium
decay products
Diffuse NORM Wastes
• Radionuclides associated with geothermal
energy production
– Th-228
– Ra-228
– Ra-226
– Po-210
– Pb-210
– TOTAL
25 pCi/g
93 pCi/g
132 pCi/g
96 pCi/g
96 pCi/g
442 pCi/g
Wastes from Geothermal Energy
Production
• Annual generation rate – 0.054 x 106 tons/y
• Total mass - 0.74 x 106 tons
• Total activity – 330 Ci
Oil and Natural Gas Production
• Are similar to geothermal wastes.
• Scale consists of barium, calcium and strontium sulfates,
silicates, and carbonates and radium compounds.
• Sludge deposits consist of barium and silica compounds –
oily and loose.
• Activities vary widely.
• Annual generation rate – 0.056 x 106 tons/y
• Total mass - 4 x 106 tons
• Total activity – 1,210 Ci
Diffuse NORM Wastes
• Radionuclides associated with wastes from oil and
natural gas production
Scale
Sludge
Th-228
Ra-228
Ra-226
Po-210
Pb-210
TOTAL
120 pCi/g
120 pCi/g
360 pCi/g
360 pCi/g
360 pCi/g
1,320 pCi/g
19 pCi/g
19 pCi/g
56 pCi/g
56 pCi/g
56 pCi/g
206 pCi/g
Phosphate Mining and Fertilizer Production
• Wastes generated from the mining and processing of
phosphate rock.
• Used to produce phosphate fertilizers, detergents, animal
feed, food products, pesticides, and other phosphorous
chemicals.
• Wastes include ferrophosphorous, phosphogypsum,
piping scale, and slag.
Phosphate Mining and Fertilizer Production
• In the U.S., about 150 million tons of rock mined
annually.
• Florida produces about 91% of the rock
• Other states – Tennessee, Idaho, Missouri, Montana,
Utah, Wyoming, Georgia, and North and South Carolina.
• Contains high concentrations of K, Ra, Th, and U.
Phosphate Mining and Fertilizer Production
• Both wet (southeastern states) and dry mining (western
states) processes are used.
• About 12-15 million tons of phosphate fertilizer are
produced annually.
• Distribution of 120 Ci of Ra-226 annually on agricultural
lands.
Phosphate Mining and Fertilizer Production
• The same radionuclides found in coal are found in
phosphate rock
• Some concentrations are very uncertain
–
–
–
–
Ferrophosphorous
Phosphogypsum
Scale
Slag
1.2 pCi/g*
113 pCi/g
1000 pCi/g*
192 pCi/g
*A very rough estimate of Ra-226 activity concentration only
Activities in Phosphate Rock in the U.S.
226Ra
238U
232Th
(pCi/g)
(pCi/g)
(pCi/g)
Tennessee
4
4
0.5
North Carolina
18
26
1
Montana
41
38
0.7
Florida
54
52
1.6
South Carolina
130
130
2.1
State
Florida Phosphate Areas
Phosphoric Acid and Fertilizer Production
Phosphorus Production
Summary
• NORM Wastes – wide spread
– Discrete wastes
– Diffuse wastes
– Naturally-occurring materials
• NARM Wastes – often man-made
– Accelerator produced
– Accelerator materials
– Naturally-occurring materials
Questions

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