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NORM Final Disposal Options

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Title: NORM Final Disposal Options


1
NORM Final Disposal Options (risk cost
considerations) Gert Jonkers Engineering
Analytical - GSEA/4 Problem Solving (Shell EP
Ionising Radiation/NORM HSE Expert
CHP) location Shell Research Technology
Centre, Amsterdam P.O. 38000 NL-1030 BN
Amsterdam the Netherlands
2
NORM after abandonment - Internal External
Radiation Hazard
TARGET Reducing both External and Internal Dose
by Naturally Occurring Radionuclides in Deposits
(NORM ) from former Gas/Oil Production Activities
to a Negligible Level for Future Inhabitants
Ingestion Determine amount of radioactivity in
the food chain. Inhalation Potential (topsoil)
dust activity levels extremely low. External (Sub
)soil activity levels sufficient low.
a
b
g
3
NORM (PRE)TREATMENT OPTIONS (pre-disposal)
Target Method NORs left in Vol.
Reduct. Produced Water Filtration plant (Matrix
reinjection) TDS/TSS gt 99 Filtering/Gravity
separation TDS/TSS gt 99 Sludge Thermal
(physical) Solids gt 99 De-oil/de-scale
(mechan-/chem-ical) Solids/TDS gt
95 Bio/chemical/physical ? Solids gt
95 Vitrification glased solids gt 95
? Incineration ? slag/fly-ash gt
95 Contamination Scale-water/grit/CO2-pellets
Jetting Liquid/Solid gt 95 De-scaling
(chelating agents) TDS gt 99 Scrap
melting slag/fly-ash gt 90 Soil Wash
(mechanical/chemical) TDS/TSS gt
95 Waste Immobilisation (bitumen/polymers) drums
0
4
NORM FINAL DISPOSAL OPTIONS
Dilution into the Environment
Controlled Surface Storage
Injection in Sealed Reservoir
Immobilisation Sealed Subsurface Storage
5
Conditional Release Limits (CRL)
to be issued and endorsed by the competent
authority for radiation workers, workforce/public
at large source constraint for dose control
radiation workers 20,000 mSv/a workers (2,000
h/a) 1,000 mSv/a public 1,000 mSv/a NORM-
source constraint 300 mSv/a
set of enveloping exposure scenarios
encompassing all industrial uncontrolled work
with NORM leading to workforce/public exposure
gas/oil industry-specific exposure scenarios
encompassing dedicated radiation protection
controlled work with NORM potential future
public use NOR-contaminated items
set of NOR-specific Conditional Release Limits
(CRLs only to be applied within the constraints
of the gas/oil industry specific exposure
scenarios)
set of NOR-specific Unconditional Release Limits
(URLs may be applied under all circumstances)
Generic EP or Group operating unit specific
scenarios competent authority enveloping
scenario's Generic CRLs for EP NORM disposal
URLs
CRL (Bq/g) 226Ra 210Pb 228Ra 228Th Condition
Spreading Sludge farming Shallow disposal
Deep hole disposal
226Ra 210Pb 228Ra 228Th EU BSS 0.5 5 1 0.5 IC
RP 2005 1 1 1 1
6
Dose Assessment Study ? Conditional Release Limit
(referenced against the NORM Source Constraint
defined the Competent Authority)
  • Collection/compilation of site specific data
    characterising the (geo)hydrological setting,
    climate conditions, background radiation levels
    and radioactivity concentration in various
    environmental media including soil, subsoil,
    surface water, ground water, airborne dusts,
    fauna and flora.
  • Identification and quantification of the source
    terms (input of NORM for intended final disposal
    option), the chemical and physical form of the
    radionuclides the points of release, and the time
    distribution of release.
  • Identification of the potential environmental
    pathways.
  • Identification of the critical population,
    defining (conditional) scenarios
  • Assessment of the individual dose using a
    computer modelling.

7
Assume Worst Case Scenario, but dont loose
reality
8
NORM FINAL DISPOSAL.
  • Environmental exposure acceptability
  • Public acceptability
  • Economic acceptability
  • Universal acceptability
  • Time to make the option viable
  • Time for industry use once the option is viable

9
DOSE ASSESSMENT REQUIRES MODELLING
  • Versatile RESidual RADioactivity code (all
    pathways) applicable to
  • Soil Contamination (Landspreading, Cleanup)
  • Shallow Burial (Landfill, special fills)
  • Deep Burial
  • Specific In-house (Shell)
  • flat source (external radiation, microshield),
  • sludge farming (external dust)

Have developed dose assessment, incl. site/target
specific parameters
Deep downhole disposal (matrix or fracture
injection) other in-house disciplines
  • In-house (Shell)
  • Mores,
  • FORDAM

10
Dilution into the Environment
Sludge farming (Landspreading) with dilution
includes mixing of the applied wastes thoroughly
within the topsoil. The area covered may be
arbitrarily large. Analyses of landspreading with
dilution also are based on incremental increase
of NOR concentrations above background levels,
and thus are also restricted to one-time disposal
in a given area (record-keeping!). 0.2 ltgt 5
Bq226Raeq/g Grinding (de-oiled) scales to a
prescribed particle size distribution and
subsequent overboard disposal dilutes these
materials into the marine environment. Disposal
is based on incremental increase of NOR-
concentrations above natural marine background
levels. Record-keeping and possible radiation
surveys to characterise pre- and post-spreading
radiation levels around platforms are measures to
control the impact on the marine environment. lt
5 Bq226Raeq/gsolid Cleanup criteria for soil
contamination. Scraping of contaminated soil,
leaving remnant (residual) radioactivity
levels. lt 5 Bq226Raeq/gsoil
11
Controlled Disposal
Land based burial with unrestricted site re-use
may occupy any available land area with minimal
or no groundwater(flow). There may be some
requirements like de-watering/oiling,
solidification, consolidation, packaging (crates,
boxes, drums) or compaction, before the waste is
actually buried in (lined) trenches, more than
2.5 m deep (intrusion limit). After burial the
trenches generally are capped with clay or other
low-permeability cover material, gravel drainage
layers and a topsoil layer. Capping the waste
with concrete prevents erosion or water leaching.
In arid climates, measures may be taken (e.g.
dumping of large rock material on top) to
discourage temporarily dwelling construction
(e.g. Bedouins), while in other climates sites
are contoured and replanted with vegetation for
drainage and erosion control. This disposal
method may also be applied to NOR-contaminated
items. Strongly related option is burial of
NORM sludge and scale in (deep) surface mines.
Possibly with some pre-treatment requirements
NORM is placed at the bottom of mine
excavations and is subsequently buried by
accumulated earthen overburden. Typical burial
depths are 15 m or greater, and areas are
sufficient to accommodate relatively large
volumes of wastes. Because of the significant
burial depths, the potential for erosion or
intrusion into the wastes is remote. Other
designated (municipality, oilfield waste,
hazardous material, low level) waste sites may
take NORM waste. 5 ltgt 200 Bq226Raeq/g
12
Deep Geological Disposal
Engineered deep underground geological disposal
facilities for high or intermediate level waste
final disposal may be available. These facilities
are used c.q. have been proposed due to their
inherent isolation of the wastes from groundwater
and from the surrounding environment. Salt
provides impermeable containment of wastes at
depths of 1,000 m or more. The salt formation
tends to self-anneal any containment defects that
may occur, further assuring containment of the
wastes. NOR-contaminated sludge, scale and/or
gas/oil field items can also be placed in salt
domes. Salt caverns have been used to store
various hydrocarbon products and to dispose
normal oilfield waste. Matrix injection consists
of injecting produced water into a deep permeable
formation below underground sources of drinking
water with no fresh water or mineral value. The
formation is confined by impermeable layers that
are likely to remain intact. Fracturing injection
consists of adding sludges and pulverised scales
to a carrier fluid (typically brine) and pumping
the mixture into a well of sufficiently high
pressure to create a fracture in a permeable
formation below underground sources of drinking
water with no fresh water or mineral value. The
fracture formed by this process is normally
vertical, confined above and below by impermeable
shale formations. After the sludge-scale water
mixture is displaced into the fracture, pressure
is reduced and the fracture closes and NORM
becomes trapped. Fill a well to be abandoned
with NORM encapsulated in connected tubulars
(encapsulation), after well is plugged and
abandonded. 1,000 Bq226Raeq/gsolid
13
NORM FINAL DISPOSAL OPTIONS (approximate CRLs
and costs/drum 1997/9 US data)
  • B q226Ra/g
  • Spreading (with dilution) 40 2
  • Sludge farming 10 2
  • Burial with Unrestricted Site Reuse 5
  • Non-Retrieval of Surface Pipe 50
  • NORM Disposal Facility 20 200
  • Commercial Oil Industrial Waste Facility 45 200
  • Commercial Low Level Waste Disposal Site
    400 200
  • Burial in Surface Mine 500
  • Well Injection 120 gt 1000
  • Plugged and Abandoned Well 200 gt 1000
  • Hydraulic Fracturing gt 1000
  • Salt Dome Disposal 10 gt 1000

14
Sustainable Environment
15
Backup Slides
16
Risk Assessment Matrix
The level of control should depend on the level
or risk !
17
very high 100,000 mSv/a
Additional Dose Restrictions Individual Dose
Limit (1,000 mSv/a) Source Constraint (300 100
mSv/a) Exemption (10 mSv/a)
Typical 10,000 mSv/a
background 2,400 mSv/a
source
18
ESTABLISHMENT OF GENERAL EXEMPT LIMITS
RISK
Likelihood of Fatal Cancer
Source Dose Constraint to be endorsed by the
Competent Authority
DOSE
Forward Calculation - Applied for Deriving
Unconditional Release (Exempt) Limits or for
Determining Compliance with Dose or Risk
Standards
Effective Dose in Sievert
EXPOSURE
Derived Limits to be endorsed by the Competent
Authority for any circumstance (Unconditional)
External Internal
CONCENTRATION (air, water, soil)
Becquerel per m3, L or g
19
HIERARCHY OF DOSE QUANTITIES
Absorbed Dose (Gy)
energy imparted by radiation to unit of mass of
tissue (J/kg)
Equivalent Dose (Sv)
absorbed dose weighted for harmfulness of
different radiations (wR)
Effective (Whole Body) Dose (Sv)
equivalent dose weighted for susceptibility to
harm of different tissues (wT)
Collective Effective Dose (manSv)
effective dose to all people exposed to a source
of radiation
20
EXPOSURE OF NATURAL BACKGROUND RADIATION
Everyone is Exposed to Natural Background
Radiation Worldwide Population Averaged Natural
Radiation Dose 2,400 µSv/y
Internal Terrestrial (excl radon/thoron) 12
Internal Cosmogenic 1
Internal Radon 47
Internal Thoron 3
Terrestrial 21
Cosmic 17
21
IONISING RADIATION CANCER DEVELOPMENT
Radiation hits a molecule of a living cell. Was
that molecule a DNA molecule?
Radiation may or may not cause damage to the
molecule. Was the DNA molecule damaged?
Damage to a DNA molecule normally corrects
itself. Was the damage corrected?
An error remained in the molecule. Was that error
of any significance to the cell?
The changed characteristics of the new cells may
be harmless or harmful. Are they harmful?
Cellular reproduction rate may be too slow for
cancer to develop during the lifetime of the
individual. Is that so?
Cancer cells may be destroyed by the normal
immune system of the body. Are these cancer cells
destroyed?
Yes
A malignant disease will develop.
22
RADIATION RISKS CONSUMER GOODS (comparison of
risks expressed in dose units mSv/a) Record
static eliminator 0.01 Radioactive lightning
rod 0.5 Gas camping lantern mantle
(NORM) 2.5 Cooking on Natural Gas
(Radon) 5 Tritium wrist watch 5 Ionisation smoke
detector 10 Exempt level (PRACTICE IAEA/EU)
10 Radium wrist watch 30 Flight
Amsterdam-Houston ( 10 h) v.v. 70 Building
masonry (NORM) 70 X-Ray Photograph
(Chest) 100 Exempt level (WORK ACTIVITY EU,
ICRP-2005) 300 Living in a Dutch Dwelling
(Radon) 950 Public Limit (ICRP-2005) 1000 (World
average) Natural Background Dose
2400 (radioisotopes) Nuclear Medicine (kidney)
2500 X-Ray Photograph (Barium meal) 3500 X-Ray
Computed Tomography (CT body) 8500 Worker Limit
(ICRP-2005) 20000
23
COMPARISON OF RISKS OF (WORKING) LIFE
(fatalities per million per year) Exempt level -
PRACTICE (10 mSv IAEA/EU) 0.5 Clothing
Footwear 3.5 Timber Furniture 10 Exempt level -
WORK ACTIVITY (300 mSv EU/ICRP)
15 Textiles 35 Accidents at Work (UK) 50 Public
dose limit (1,000 ?Sv/a ICRP) 50 Metal
Manufacture 60 Accidents at Home (UK) 100 Natural
Background (world average 2,400
?Sv/a) 120 Construction 200 Road Accidents
(UK) 200 Coal Mining 250 Radiation worker Dose
limit (20,000 ?Sv/a - ICRP) 1000 Deep Sea
Fishing 2000 Smoker (10 cigarettes/day) 5000
24
Risk to People What Is Reasonable?
Smoking all accidental (non disease) all
accidental (non-disease, non transport) EP
contractors
RSSG upper bound for voluntary risk
Intolerable Too high Compareoptions Maint
ainprecautions(due care) Negligible
car driving accidents at home EP company
staff accidents at work (average all industries
US 86) playing football/rock climbing Fire Worker
s in safest industry Light manufacturing
HSE upper bound for involuntary risk

public acceptance of voluntary risk
air transport Living near nuclear installations
RSSG/HSE insignificant public acceptance of
Natural disasters
insect bites/flooding in the Netherlands lightning
strikes explosion of pressure vessel
public tolerance of man-made disasters
Proposed by Health Safety Executive, UK
25
Unconditional Release Limits (URL)
to be issued and endorsed by the competent
authority for radiation workers, workforce/public
at large source constraint for dose control
radiation workers 20,000 mSv/a workers (2,000
h/a) 1,000 mSv/a public 1,000 mSv/a NORM-
source constraint 300 mSv/a
set of enveloping exposure scenarios
encompassing all industrial uncontrolled work
with NORM leading to workforce/public exposure
set of NOR-specific Unconditional Release Limits
(URLs may be applied under all circumstances)
competent authority enveloping scenario's
URLs
226Ra 210Pb 228Ra 228Th EU BSS 0.5 5 1 0.5 IC
RP 2005 1 1 1 1
26
Dose Assessment Study ? Conditional Release Limit
(referenced against the NORM Source Constraint
set by the Competent Authority)
  • Collection/compilation of site specific data
    characterising the geohydrological setting,
    background radiation levels and radioactivity
    concentration in various environmental media
    including soil, subsoil, surface water, ground
    water, airborne dusts, fauna and flora.
  • Identification and quantification of the source
    terms (input of NORM for intended final disposal
    option), the chemical and physical form of the
    radionuclides the points of release, and the time
    distribution of release.
  • Identification of the potential environmental
    pathways.
  • Identification of the critical population.
  • Assessment of the individual dose using a
    computer modelling.

27
The End
The End
Risk of Radiation Doses Compare with Natural
Background Dose
28
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