Certified Radiation Protection Officer-RPO
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Basic Radiation Safety Training
➢Required for all users of radioactive material.
➢Covers material license conditions, regulations and all safety practices associated with use of radioactive materials.
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Course Outline
•Organizational Structure of the Program
•Radiation Safety Principles
•Biological Effects and Risk
•Postings and Labels
•Contamination Control and Spills
•Proper Survey Techniques
•Survey meter and wipe test
•Radiation Safety Checklist
•Security of stock vials
•Radioactive Waste Disposal
•Contact Information
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Greek philosophers thought all the matter in the world was made of tiny unbreakable kernels they called atoms
Nothing was smaller than an atom
- it couldn’t be broken into parts
5000 B.C.
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Roentgen’s Discovery
•In 1895 German physicist Wilhelm Roentgen accidentally discovered a new form of energy which he named the x-ray
•Roentgen produced first x-ray image - his own hand
•His work sparked feverish research, especially in Germany
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The New Understanding
•In 1913 several scientists published the theory that an atom is made of
–a positively-charged central nucleus
–orbited by negatively-charged particles
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Bohr Model
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World War II
•Nazi persecution caused Jewish physicists to leave Germany
•The physicists understood that splitting the atom would release tremendous energy
•Albert Einstein and others approached President Roosevelt
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Manhattan Project
•US secret project to create atomic weapon 1942-45
•Three sites
–Hanford, Washington (plutonium fuel)
–Oak Ridge, Tennessee (uranium fuel)
–Los Alamos, New Mexico (bomb production)
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Atomic Structure
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Nucleus
•Contains positively-charged protons
•Non-charged neutrons
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Electrons
•Orbit nucleus
•An atom can have as many electrons as it has protons
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How big is an atom?
•An atom is the same size compared to a golf ball
•As a golf ball is compared to the earth
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The Search for Stability
nAn atom is stable based on it’s proton to neutron ratio
nIf there are too many or too few neutrons or protons, the atom will give off excess energy as
urays
uparticles
nThis process is called radioactive decay
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What is Radiation?
Energy in motion
•As either particles or rays
•Two kinds: ionizing and non-ionizing
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Fission
–Fission is the process by which a large, unstable nucleus splits into two nuclei
–It rarely occurs naturally
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Fission
•When the atom splits, “fission fragments” are released
Basic Terms
➢Radiation: energy in transit in the form of high speed particles or electromagnetic waves.
➢Radioactivity: Characteristic of an unstable atom that releases energy in the form of a particle or electromagnetic wave.
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Types of Radiation
➢Ionizing Radiation: Radiation capable of liberating electrons from an atom.
ex. beta particles, x-rays
➢Non-ionizing radiation: Radiation not capable of liberating electrons, but can excite the atom.
ex. microwaves, radio waves, lasers
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Types of Ionizing Radiation
➢Alpha particles: contains 2 neutrons and 2 protons, which is ejected from the nucleus of a radioactive atom.
➢Beta particles: A high-speed electron or positron, usually emitted by an atomic nucleus undergoing radioactive decay. Electrons carry a negative charge.
➢X-rays: Electromagnetic radiation originating in the electron field of an atom.
➢Gamma rays: A gamma ray is an electromagnetic radiation originating in the nucleus of an atom.
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Ionizing Radiation
•The energy given off by the nucleus is called ionizing radiation
•It is strong enough to detach an electron from an atom
–When an atom loses an electron, it has a positive charge and is called an ion
–The ion and its lost electron are called an ion pair
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Non-Ionizing Radiation
•Energy in transit that is too weak to detach an electron from another atom
•Examples
–Light
–Radio and television waves
–Microwaves
Ionizing Radiation –
Why Worry?
Why Worry?
•Ionizing radiation health risks:
➢Acute effects – high levels of radiation produce effects such as blood chemistry changes, nausea, fatigue, various skin effects, cataracts, and death
➢Delayed effects – at some lower level of radiation, can increase risk of some cancers
•What about at typical environmental and occupational dose levels? No risk? Hormesis? What are the implications?
•Radiation is a weak carcinogen compared to other materials (beryllium, asbestos, tobacco smoke…)
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Radioactive Decay
•When an atom’s nucleus gives off excess energy, the process is called radioactive decay
•Radioactive half-life is the time it takes half the radioactive atoms present to decay
Half-Life
•The time it takes half the radioactive atoms present to decay
Before
After one half-life
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Half-Life
nThe time it takes half the radioactive atoms present to decay
Before
After one half-life
Alpha Particle
•Large mass
•Consists of 2 protons and 2 neutrons
•Electrical charge of +2
•Range in air 1 to 2 inches
+1
+1
Alpha shielding
•A sheet of paper
•Outer layer of skin
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Biological Hazard
nAlpha radiation is not an external hazard, because it can be stopped so easily
nIf inhaled or swallowed, the alphas emitted from an alpha emitter, can deposit large amount of energy in a small area of body tissue
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Biological Hazard
nAlpha radiation is not an external hazard, because it can be stopped so easily
nIf inhaled or swallowed, the alphas emitted from an alpha emitter, can deposit large amount of energy in a small area of body tissue
Beta Particle - ß
•Small mass
•Electrical charge of -1
•Emitted from nucleus
•Range in air about 10 feet
Beta Shielding
•Beta has a limited penetrating ability because of its negative charge
•Most beta particles can be shielded by plastic, glass, metal foil, or safety glasses
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Biological Hazard
•If ingested or inhaled, a beta-emitter can be an internal hazard
•Externally, beta particles are potentially hazardous to the eyes and skin
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Beta Sources
•Uranium decay products
•Decay of some radioactive substances (Tritium)
•Products of the fission process
Gamma and X-Rays
nAn electromagnetic wave or photon, which has no electrical charge
nGreat penetrating power
nRange in air easily several hundred feet
Gamma and X-Ray Shielding
nConcrete
nLead
nSteel
Background Radiation
People around the world are continually exposed to radiation from natural sources
•These sources include:
➢Cosmic radiation from outer space
➢Terrestrial radiation (materials in the earth)
•Internal radiation from materials taken into the body through breathing air, drinking water, and eating foods
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Radiation is Energy
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Radiation Units
➢There are two systems of units used in the measurement of radioactivity and radiation dose.
➢The older units (Curie, rad and rem) are commonly used in U.S. regulatory language.
➢The SI units (Becquerel, Gray and Sievert) are commonly used internationally.
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RADIATION MEASUREMENT
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Roentgen (R)
nA unit for measuring exposure
nDefined for effect in air only
nApplies only to gamma and x-rays
nDoes not relate radiation to the effect on the human body
1 R = 1000 milliRoentgen (mR)
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Roentgen Absorbed Dose (rad)
nUnit for measuring the absorbed dose in any material
nApplies to all types of radiation
nDoes not take into account differing effects on the human body
n1 rad = 1000 millirad (mrad)
1 rad= 1000 millirad (mrad)
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Radiation Absorbed Dose (rad)
nUnit for measuring the absorbed dose in any material
nApplies to all types of radiation
nDoes not take into account differing effects on the human body
n1 rad = 1000 millirad (mrad)
1 rad= 1000 millirad (mrad)
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Roentgen Equivalent Man (rem)
nUnit for measuring radiation equivalence
nMost commonly used unit
nTakes into account the energy absorbed (dose) and effect on the body of different types of radiation
1 rem = 1000 millirem (mrem)
Radiation Quantities
Curie: 3.7x1010 disintegrations per second or
2.2x1012 disintegrations per minute.
1 milliCurie (mCi) = 2.2 x 109 dpm
1 microCurie (mCi ) = 2.2 x 106 dpm
100 mCi = 0.1 mCi
Becquerel: one disintegration per second. (SI system)
1 mCi = 3.7x107 dps = 37 MegaBecquerel (MBq)
1 mCi = 3.7x104 dps = 37 kiloBecquerel (kBq)
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Radiation Quality Factors
Two different types of radiation may deliver the same absorbed dose, but produce a different biological effect, and hence, dose equivalent.
1 rad of alpha = 20 rem
1 rad of beta = 1 rem
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Half-Life
➢The time required for any given radioisotope to decrease to one-half of its original activity by radioactive decay.
➢This period of time is called the half-life
32P - 14.3 days 14C - 5730 years
3H - 12.3 years 35S - 89.7 days
125I - 60 days
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External Exposure
➢Common isotopes with external exposure potential
P-32, I-125, Cr-51
➢Not all radioisotopes are external exposure hazards
H-3, C-14, S-35
External exposure occurs when all or part of the body is exposed to penetrating radiation from an external source.
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Pathways of Internal Exposure
➢Ingestion
➢Absorption
➢Inhalation
➢Puncture
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Contamination and Exposure
Radioactive Contamination is
Radioactive material where it shouldn’t be. e.g. floors, bench tops, hands
Fixed vs. Removable Contamination
All radioisotopes have contamination potential even if they do not have external exposure potential.
The goal is to prevent contamination from getting on to your skin and/or inside your body.
How Contamination Differs From Exposure:
A person exposed to radiation is not necessarily contaminated with radioactive material.
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You are NOT radioactive if you receive an external exposure from radioactive material.
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ALARA
➢The goal of radiation protection is to keep radiation doses As Low As Reasonably Achievable
➢BUMC is committed to keeping radiation exposures to all personnel ALARA
NCRP Definition of ALARA
As Low As Reasonably Achievable (ALARA): A principle of radiation protection philosophy that requires that exposures to ionizing radiation be kept as low as reasonably achievable, economic and social factors being taken into account. The protection from radiation exposure is ALARA when the expenditure of further resources would be unwarranted by the reduction in exposure that would be achieved.
Contributions from Man Made and Natural Background Source of Radiation
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From NCRP Report No. 160, “Ionizing Radiation Exposure of the Population of the United States” (2009)
Annual Exposure
620 millrem/yr.
620 millrem/yr.
NCRP SUMMARY
•Average dose to individual is 620 mrem/yr
–Approximately 37% of dose was attributed to radon
–An additional 13% attributed to other natural sources (cosmic, terrestrial, internal)
–Total ~50% attributed to natural sources
–Medical comprised ~48%
–Dose from nuclear power was grouped into a category comprising <0.1%
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Annual Occupational Exposures
Average dose/year
*Annual Allowable Exposure limit for Radiation Worker = 5000 mR/yr
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Latest Biological Effects Studies
If 100,000 persons were exposed to 10 Rem of radiation each, 800 excess cancer deaths would be expected during their remaining lifetimes in addition to the nearly 20,000 cancer deaths that would occur in the absence of radiation.
- BEIR V Report, page 162 - 1989
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Genetic Effects
➢Damage to cells DNA
➢Effects have not been observed in human populations
➢Extrapolated from larger doses and animal studies
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Declared Pregnant Worker
Any radiation worker who is pregnant may voluntarily declare her pregnancy and the estimated date of conception in writing to the DMPRS and thereafter her occupational radiation exposure shall be limited to 500 millirem (50 millirem/month) for the entire period of gestation.
If you are pregnant and want to declare pregnancy, please contact the DMPRS for consultation.
Ref: US NRC Regulatory Guide 8.13 rev. 3 1999
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MINIMIZE EXTERNAL EXPOSURE
Time
(Reduce exposure time)
Distance
(Increase Distance)
Shielding
(Place dense object between you
and source of radiation)
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How To Minimize External Exposure
TIME : 60 mR/hr = 6 mR in 6 minutes
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How To Minimize External Exposure
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Shielding
•Alpha particles can be stopped by a sheet of paper.
•Most Beta particles can be stopped by 1-2 cm of plexiglass.
•Most gamma and x-ray photons can be absorbed by several cm of lead.
•Neutrons may require several feet of concrete.
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Do you work
directly with a
source of radiation?
No
Badge
Required
Is the radiation
source an
isotope or a machine?
No
Yes
Do you work with one of the following
isotopes? * badge type in ( )
➢ Brachytherapy Sources (1 and 4)
➢ >1 mCi. of gamma or
positron emitter (1 and 4)
➢ >1 mCi. high (>500 keV)
max energy Beta emitter (1 and 4)
➢Nuclear Medicine (1 and 4)
Do you work with any one of the
following machines? * badge type in ( )
➢Fluoroscope (2 and 3)
➢LINAC (1)
➢Diagnostic x-ray (1)
➢CT (1)
Isotope
Machine
A badge is
mandatory
A badge is
voluntary
Yes
No
No
Badge Type
(1) – Whole body
(2) – Collar
(3) – Waist
(4) – Ring
Dosimetry Requirement Decision Tree
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Labeling
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Refers to quantities of radioactive material used or stored.
Refers to areas accessible to personnel, in which a major
portion of the body could receive a dose of 5 mrem in any one hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates
Postings
2 Postings:
•“Notice to Employee”
•“Rules Governing the Use of Radioactive Materials”.
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Contamination
➢Definition: Radioactive material where it shouldn’t be.
e.g. floors, bench tops, hands
➢All radioisotopes have contamination potential even if they do not have external exposure potential.
➢The goal is to prevent contamination from getting on to your skin and/or inside your body.
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Skin Contamination
➢Cool water, mild soap
➢2-3 minutes working up a good lather, dry
➢No harsh chemicals or detergents
➢Survey for contamination
➢Notify the RPO 617-638-7052
➢BUMC -Control Center 617-638-4144
off hours (8-6666)
➢CRC-617-353-SAFE
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•Notify the people in area that a spill has occurred
•Report incident to the DMPRS
•Prevent the spread of contamination. Cover the spill with absorbent material and prevent access to the area by unauthorized personnel
•Clean Up using disposable gloves
•Survey area with a low range thin window GM survey instrument
Emergency Office Phone
Medical Campus - RPO 617-638-5795
- Control X 8-4144 (off-hours)
Charles River Campus - 3 -SAFE (24 hours)
Spill Response
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Direct Survey
Survey Meters
Survey Meters
•“Pancake probe” Model 44-9
•Used to monitor: 14 C, 35S, 32P, 33P
•Move slowly at 2 inches/second from a distance no greater than 1 cm above the surface
* Annual Survey Meter calibration is required
•Model 44-3 known as a “Scintillation” or “NaI” Probe
•Used to monitor low energy gammas such as I-125
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Radiation Detection Instruments
Liquid Scintillation counter is required for Tritium Contamination surveys
End Window
(S-35, P-32, P-33, C-14)
*Lower Detection Efficiency than End Window
Pancake
(S-35, P-32, P-33, C-14)
*Better Detection Efficiency than End Window GM
Portable Survey Meter
Gamma Scintillator (NaI) probe
(I-125 and Cr-51)
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Proper Survey Technique
➢Use appropriate survey meter
–Check Calibration Status (Sticker)
–Check battery
–Audible on
–Check background level
–Start at the lowest scale
Audio On/Off Switch
Rotary Switch Off Battery Check Scalar Multiplier
Battery Compartment
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Survey Meter Face Plate
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Scale: 0 - 5 K cpm on X 1 multiplier
*Some meter faces will have the Middle and Bottom scale (As shown on left). In research setting the CPM scale is the only scale we use
Use This Top Scale
Direct Monitoring
•Set meter on lowest scale and observe background.
•Bring probe 1/4 to 1/2 inch from surface without touching.
•Move probe slowly. (2 inches/sec)
•Listen for audible chirp and observe count rate.
•Results expressed in units of counts per minute (CPM).
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Wipe Tests
➢A wipe test only assesses removable contamination.
➢Use absorbent paper to wipe an (100 cm2 )area
➢For H-3, a wipe test is the only means to assess potential removable contamination.
➢For other isotopes (i.e. P-32, S-35, C-14) a Geiger Counter may be used to assess removable contamination. (Note: efficiency is much lower than wipe test counted with LSC)
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Liquid Scintillation Counter
Radioisotope Ordering Process
1.Order placed through DMPRS via BU Works ISR
2.DMPRS places order with vendor
3.Package arrives at DMPRS for inspection
4.DMPRS delivers package to your lab
5.Lab personnel (RAM authorized user) receives and secures package.
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•You must do the following:
➢Keep radioactive material in constant view
➢Lock up radioactive stock solutions
➢Lock the laboratory
➢Always keep the access door to your floor of the building locked.
–(Use Key Card Access or the Combination Lock)
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Radioactive Material Transfer
Contact DMPRS for authorization prior to transfer of radioactive material on and off campus.
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Requirements for Packages
●General Requirements
●Easily and safely handled and transported
●Strong lifting attachments
●Free from protruding features
●Surface will not retain water
●Withstand effects of acceleration and vibration
●Physically and chemically compatible components
●Temperature range from -40o C to + 55oC
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Type A Package
●Meet General Package requirements
●Smallest outside dimension >100 mm
●Capability of installing a tamper proof seal
●Forces on tie-down attachment must not damage package during transport
●Temperature range -40oC to + 70oC
●No loss or dispersal of material or a 20% increase in radiation level after water spray, free drop, stacking, and penetration tests.
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Empty Packages
●Previously contained radioactive material
●Well maintained and securely closed
●No loose contamination
●Any labels which may have been displayed are no longer visible
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Category
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Maximum radiation level at any point on External surface
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Transport Index
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I-WHITE
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Not more than 0.005mSv/hr (0.5 mrem/hr)
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0 (< 0.05)
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II-YELLOW
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More than 0.005 mSv/hr (0.5mrem/hr) but Not more than 0.5 mSv/hr(50 mrem/hr)
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0 to < 1
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III-YELLOW
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More than 0.5 mSv/hr(50 mrem/hr) but Not more than 2 mSv/hr(200 mrem/hr)
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1 to < 10
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III-YELLOW and also Under exclusive use
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More than 2 mSv/hr(200 mrem/hr) but not more than 10 mSv/hr(1,000 mrem/hr)
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More than 10
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Shipping Labels
●Transport Index < 0.05
●Surface < 0.5 mr/hr
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Shipping Labels
●Transport Index <10
●Surface <200 mr/hr
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TRANSPORT INDEX
TRANSPORT INDEX:
●The radiation level in mr/hr at one meter from the package surface (gamma and neutron).
TRANSPORT INDEX
ONE METER
3.3 FEET
39 INCHES
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Overpack
●An enclosure that is used by a single consignor to provide protection or convenience in handling of a package or to consolidate two or more packages.
●Packages of radioactive material may be combined in an overpack for transport.
●Only the shipper is permitted to take a direct measurement of the radiation level to determine the TI.
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Special Form
●Indispersible solid or sealed capsule which meets the following:
●Capsule can only be opened by destroying it
●Have one dimension not less than 5 mm
●Design received unilateral approval
●Demonstration of compliance with the standards can be done by performance, reference to previous tests, or calculations
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Special Form
●Subjected to impact test, percussion test, leaching test, volumetric leakage test, bending test, and heat test
●Would not break or shatter under the impact, percussion or bending tests
●Would not melt or disperse in the heat test
●Would not leak
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Package Markings
●Readily visible and legible
●“Type A” must be stamped or printed as required
●Proper shipping name
●UN Number
●Excepted packages only require UN Number
●Shipper and Consignee with addresses
●Gross mass if exceeding 50 kg
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Marking of Overpacks
●Proper shipping name
●UN number
●All labels except for the “Type A” package label that are required on the inner package must be reproduced on the outside of the overpack
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Package Labeling
●Identification of primary hazard
●Able to withstand open weather exposure
●Two labels which conform to the appropriate category on two opposite sides of the package or on the outside of all four sides of the freight container
●Labels must not be folded
●Labels must not overlap
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Package Labeling
●Cargo Aircraft Only label for goods transported into or out of US
●Category Labels must have
●Contents – symbol of radionuclide – mixtures as space permits
●Activity in Bq can have Ci in parentheses
●Transport Index for category II and III
Iodination Precautions
➢Verified negative pressure hood
➢Double glove
➢Lab coat
➢Double bag radwaste
➢Lead bricks in front of hood causes turbulence
➢Use charcoal to absorb iodine vapors
➢Air sampling and thyroid monitoring required
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Fume Hood
REQUIRES ADDITIONAL TRAINING:
Iodination procedures
Sulfur 35 - Amino Acid Precautions
Because of volatility:
•Open Stock vial in hood
•Place charcoal in incubators, water baths, etc.
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Phosphorous-32 Precautions
➢3/8 inch lucite
➢lab coat, double gloves,
safety goggles
➢absorbent paper or trays
➢Dosimetry (> 1 mCi) whole body badge and ring dosimeter
➢Geiger counter
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Use flat top tube opener to reduce radiation levels to fingers
Use of Radioactive Materials in Animals
➢Radioactive material in animal use must be approved by
–Radioisotope Committee
–IACUC (Animal Care Committee)
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Radioactive Waste Categories
a. Solid waste
b. Aqueous liquid waste
c. Organic liquid
d. Deregulated liquid scintillation vials
e. Regulated liquid scintillation vials
f. Animal carcass/tissue
g. Volatile material
h. Stock vials
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Radioactive Waste Guidelines
Environmental Waste Management approved containers by half-life:
< 30 DAYS, 30-90 DAYS, > 90 DAYS
➢4 ml thick plastic bag
➢Inventory sheet
➢No radioactive waste is allowed in cold trash or biohazard bags
➢All rad labels must be defaced before placing in waste containers
➢waste pickups are scheduled on-line
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Radwaste Guidelines
➢Put radioactive needles etc., in “radioactive” sharp container
➢No liquids
➢No lead pig (Deface and store lead pigs in separate containers next to waste. Environmental management will pick up at time of waste pick up)
➢Assure radwaste container labeled to prevent housekeeper from emptying trash
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Sink Disposal
•You must ensure:
➢Liquids disposed down sinks designated for radioactive liquid disposal only.[No mixed waste].
➢Activity/Isotope disposed are less than the posted sink limit.
➢Liquid is aqueous, soluble, and dispersible.
➢Sink disposal log is complete
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Radiation Safety Records
Are all records filled out and up to date?
➢Inventory
➢Surveys
➢Waste logs
➢Sink logs
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Inventory Records
You record:
➢What material was received
➢When it arrived (day, month and year)
➢Activity received
➢Chemical form
➢When it was used, who used it
➢Running total of activity on hand
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Telephone Numbers
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Radiation Safety Committee (RSC)
Radiation Safety Officer
Division of Medical Physics and Radiation Safety (DMPRS)
Radiation Safety Officer
Division of Medical Physics and Radiation Safety (DMPRS)
•The (RSC) oversees all uses of radioactive material permitted by the materials license and has overall responsibility for development and recommendation of comprehensive polices and guidelines for the safe use of all sources of radiation
•The RSO ensures that radiation safety activities are being performed in accordance with approved procedures and regulatory requirements
•Medical Physics and Radiation Safety is responsible for ensuring that all clinical and research uses of radioactive materials is safe for workers, patients and the general public
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You Want To Be
an RSO
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What is a Radiation Safety Officer?
An individual who…
•meets the regulatory training/experience requirements
•Is identified on a license that authorizes medical use of radioactive material and/or radiation machines
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RSO Training Requirements
•Current regulatory training/experience
requirements don’t need to be met if you
had already been identified as an RSO
on a….
oLicense issued by an Agreement State or NRC
o Permit issued by a broad scope license
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RSO Training Requirements
• For a medical physicist…
Certification by a specialty board whose
certification process has been recognized
• Experience in radiation safety for similar
types of use of radioactive material
• Training in radiation safety, regulatory
issues, emergency procedures for types of
use radioactive material
• Written attestation of the above
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Recognized Specialty Boards
•Board of Health Physics (1/1/2005 to present)
•Board of Science in Nuclear Medicine
(6/1/2006 to present) for
➢ Nuclear medicine physics & instrumentation
➢ Radiation protection specialty
•Board of Radiology (6/2007 to present) for
➢ Radiologic physics-medical nuclear physics
➢ Radiologic physics-diagnostic radiologic physics
“RSO Eligible” appearing above BR seal
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Responsibilities of the RSO Serve as the primary contact with the regulatory agency Establish & oversee operating, safety and emergency procedures Ensure surveys/leak tests are performed and documented Handle monitoring of occupationally-exposed personnel
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•Assume control and initiate corrective actions in emergency or unsafe conditions
•Investigate incidents
•Implement corrective actions
•Perform inventories
•Ensure proper labeling, transport, use, and disposal of radioactive material
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Responsibilities of the RSO
•Identify radiation safety problems
•Have a thorough knowledge of
management policies and administrative procedures
•Ensure personnel are complying with
rules and OSE procedures
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NORMS
Natural
Occurring Radioactive Materials
Outline
•Definitions
•Sources and types of NORM/TENORM
•NORM Regulations
•Oil and Gas Industry NORM Wastes
•NORM/TENORM Radiation Safety
Naturally Occurring Radioactive Material (NORM) – any nuclide that is radioactive in its natural state ( i.e. not man-made), but not including source, by-product, or special nuclear material.
NORM Definition
Uranium
ppm
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Thorium
ppm
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Limestone
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0.03 - 27
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0 - 11
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Sandstone
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0.1 - 62
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0.7 - 227
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Origins of NORM
●NORM in earth crust
●NORM in reservoir rock formations
●NORM in Formation water
●NORM in Natural gas
●NORM in Sea water
NORM nuclides of interest to oil industry
• Radium-226 & Radium-228
•Uranium
•Radon-222
•Lead-210
•Polonium-210
Which NORM !
Relative Penetrating Power
Radiation Emitted by NORM
●Gamma rays
Ra-226 and Pb-210
●Beta particles
Ra-228, Pb-210, Bi-210
●Alpha particles
Ra-226,U-238,Po-210 and Pb-210
Where NORM accumulates
NORM may accumulate in the following media:
●Scale
●Scrapings
●Sludge
●Thin films (radon progeny)
NORM in Scale
●Types of scales
–Sulfate: SrSO4 and BaSO4 (RaSO4)
–Carbonate: CaCO3 (RaCO3)
●Effect of water mixing
●Change in pressure/temperature
●Scale accumulates in: production tubing, well head, valves, and pumps
●Scale inhibitors
NORM in Scale
NORM in Pipelines Scrapings
●Crude pipelines
(Radium & Pb-210)
●Seawater pipelines
(Uranium)
NORM in Gas Processing Facilities
●Radon path
●Radon progeny
●Pb-210 (22 years)
●Po-210 (138 days)
●Bi-210 (5 days)
Form thin films on: compressors, reflux pumps, control valves, product lines/vessels.
Boiling Point
(K, 1 Atm)
| |
Ethane
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185
|
Radon
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211
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Propane
|
231
|
NORM as a Public Health Issue and a Public Perception Issue
•Basic interactions of people and their environment
•Must understand, assess, and control
–Impacts of people on their environment
–Impacts of the environment on people
•Oil and Hydraulic Fracturing waste may contain radioactive materials
➢What are these materials?
➢When is this a concern?
➢When/how is it regulated?
Definitions
NORM: Naturally Occurring Radioactive Material – U, Th, Ra, Rn, etc.
or if you prefer:
Cheers regular; loves beer
➢Some oil and gas drilling waste (shale)
➢Fertilizer (from phosphate ores – uranium)
➢Rare earth mine tailings (uranium, thorium)
➢Ceramic products (uranium in clay)
➢Welding rods (thorium sands in coatings)
Definitions (Cont’d)
•TENORM: Technologically Enhanced NORM – natural material whose radioactive concentrations have been enhanced by human activities including:
➢Oil & gas pipe scale
➢Oil & gas sludges
➢Selected mining wastes
➢Coal ash (concentrated uranium & thorium)
Sources and Types of NORM/TENORM
•Oil field pipe scale (radium)
•Oil field/refinery sludge (radium)
•Geothermal waste (radium)
•Drinking water purification waste (uranium/radium)
•Metals and tailings from certain ores (rare earth elements)
•Coal fly/bottom ash
Oil & Gas Industry
•NORM/TENORM present in all phases
•Concentrations depend on geology
➢Higher concentrations in production phase (scale/sludge)
➢Drill cuttings
➢Produced water/flowback water
➢Radon decay products in gas production equipment
•Gas well drillers often use well logging to determine radiation levels to find gas
NORM Contamination
•Radon gas, external exposure, internal exposure
•Potential:
➢Worker exposure
➢General public exposure (and associated litigation risks)
➢Environmental impact
Who Regulates NORM?
•EPA – sets federal radiation standards for the public
•OSHA – has authority over hazardous materials in the workplace
•States
➢NORM-specific regulations
➢Clean Air Act
➢Clean Water Act
➢Workplace dose rates
➢Waste management
Waste Characterization
•Generators have the responsibility to know about their waste and appropriate management – DOT HAZMAT issues
•Generators should know waste characterization:
➢Can be done through analytical testing, or
➢Through generator knowledge of a waste based on defensible and demonstrated factors
➢If uncertain, generators have the responsibility to perform analytical testing
Oil Field Waste
•NORM radionuclides may be concentrated in the oil recovery process
➢Radium is more soluble in brine solutions than uranium or thorium
➢Carbonates and sulfates of calcium, barium, and strontium may precipitate as pipe scale
➢Radium will also precipitate in pipe scale
➢Sludge in refineries may also contain radium
Oil Field Waste: Example Radionuclide Content
Average Sludge Average Scale
Radionuclide pCi/g pCi/g
210Po 56 360
210Pb 56 360
226Ra 56 360
228Th 19 120
228Ra 19 120
Total: 206 1,320
Note: Typical radium-226 in soil is ~1 pCi/g
* EPA Data
Oilfield NORM/TENORM – Who is Exposed?
•General site workers
•Maintenance personnel – cutting, grinding, welding, scraping, dismantling pipes (scale/sludge)
•Pipe/equipment recyclers
•Personnel involved in remediation and decontamination operations
•Waste handlers/transporters
Oilfield NORM/TENORM – Who Else Could be Exposed?
•Members of the public
–Landowners who have leased mineral rights
–Transportation of wastes containing radioactive materials
–Water treatment plant workers – they are members of the public with respect to radiation regulations
•Legal Implications?
Radiation Safety at a NORM Facility
•Written Radiation Safety Program
•Training
•Survey Activities:
➢Instrument surveys for dose rate, contamination
➢Collect airborne dusts
➢Restrict pipe cutting area
➢PPE – air filter, gloves, other
Radiation Safety at a NORM Facility (continued)
•Instrumentation
•Dose Monitoring
•Record-keeping – if there’s no record, then it wasn’t done
–Can you defend your program if challenged?
–We live in a very litigious society so this can’t be stressed enough
What it all means to the operator
•Be familiar with your regulations
•Develop a worker protection plan
•Manage and dispose of NORM waste properly
•Provide NORM training to workers
•Know your NORM environment:
➢Sampling
➢Field Measurements
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NORM Exposure Scenarios
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●Contamination
Inhalation
Ingestion
Absorption
●Irradiation
External Exposure
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NORM Health Impact
No short-term acute effects
Chronic exposure
(unprotected)
Higher possibility of cancer
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NORM Levels
World wide reported levels of NORM
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NORM in Natural Gas
●Radon gas (Rn-222)
●EPA limit for Radon in air is 4 pCi/ liter
Medium
|
Specific activity
pCi/liter
|
Natural gas
|
0.14 – 5400
|
NGL
|
0.27 – 40500
|
Propane
|
0.27 – 113400
|
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Workers’ Radiation Dose
A worker’s dose depends on:
●Type of work
●Cleaning vessels/tanks
●Maintenance
●NORM activity
●Time
●Protective measures
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Regulatory Requirements
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WHAT IS REGULATION ?
• Regulation refers to “controlling human or societal behavior by rules or restrictions”
• Costs for some and benefits for others
• Efficient where the total benefits to some people exceed the total costs to others
• Regulatory agencies deal in regulation or rulemaking and enforcing rules and regulations for the benefit of the public at large
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SYSTEM OF REGULATORY CONTROL Issued by Central Government
Act (Atomic Energy Act, 1962)
Rules (Atomic Energy Radiation Protection) Rules, 2004)
Notifications (Radiation Surveillance Procedures for Medical Applications of Radiation, 1989)
Published by AERB
Safety Codes Safety
Standards Safety Guides
Safety Manuals
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Radiation Safety
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X-Ray Burns
5,000+ rad
500+ rad
P-32 - 6.5 rad/hr/uCi
S-35 - 2.5 rad/hr/uCi
Cancer
•Radiation can damage cells through two methods;
–Production of free radicals and
–Direct damage to the DNA.
•Risk factor for radiation dose:
–4% increase in risk of dying of cancer for every 100 rem of dose.
–Normal cancer risk is 20%.
Security and Transportation
•All radiation sources must be kept locked up when not in use.
•Experiments left unattended should be labeled “Experiment in Progress.”
•An up-to-date use log of all sources must be kept at the storage location.
•All radiation laboratories will be locked when unattended for extended periods.
•When you are the means for security, you must challenge unknown persons entering the lab.
•Sources can only be used in a registered radiation
laboratory.
•Call RPP for all transfers of sources to other authorizations.
General Radiation Safety
•No food or beverages in the lab
•Keep a survey meter conveniently close by
•ALARA - time, distance, and shielding
•Label radioactive materials and equipment
•Never remove sources from the Jr Physics Lab
Important characteristics of radiation
•Wavelength
•Frequency
•Intensity
•Velocity
•Straight line propagation
•Spectrum
•Inverse square law
Ultraviolet radiation hazards
•Common sources: sun, UV lamps (‘black lights’), welder’s arc
•Some devices may emit only a small amount of visible light while emitting intense UV radiation
•Especially dangerous to the eyes since they do not dilate readily in response to UV -- retinal burns
•Photosensitization to UV can occur from certain dermal chemicals and oral drugs (e.g. antibiotics)
Visible radiation hazards
•Common sources: sun, all visible lamps
•Major damage likely only if intense beam is focused on the retina
•Eye usually registers pain before serious damage occurs
Infrared Hazards
•Major effect is burns
•Eye is not very sensitive so can be damaged if IR is intense
•Skin burns possible but usually avoided due to pain from heat before serious injury occurs
Radio-frequency and Microwave Hazards
•Sources include analytical instruments (e.g. NMR), cathode ray tubes (including oscilloscopes, TVs, and computer monitors), microwave ovens, and communications devices (e.g. cell phones)
•Biological effects to man uncertain
•Suggestion of sterility problems, birth defects and cataracts from microwaves
•Pacemakers are effected by microwaves
LASER HAZARDS
•LASER = Light Amplified by Stimulated Emission of Radiation
•Especially hazardous due to very narrow beam which can be very intense
•Lens of eye may concentrate energy onto retina by another 100,000 times
LASER HAZARDS (cont’d)
•Use minimum power laser possible for job
•Keep laser beam off or blocked when not in use
•Post warning signs when lasers are in use
•Never look directly at a laser beam or align it by sighting over it
•If possible, use laser in lighted room so that pupils will be constricted
•Do not depend on sunglasses for shielding.
•Make sure any goggles used are for the wavelength of the laser used and are of adequate optical density
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Radiation Safety
benefits and risks
benefits and risks
Accidental and avoidable exposure to ionizing radiation is a risk.
Effects of ionizing radiation on life depend on types of radiation, rates of receiving, and dosages (amounts) received.
Natural ionizing radiation include cosmic rays, X-rays and gamma rays from space, and natural radioactivity.
Risk will be discussed in terms of types, rate of receiving, and dosages using well defined units and quantities .
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Early Experiences of Radiation Effects
Early workers exposed to X-rays developed dermatitis.
Uranium miners developed skin lesions.
People working with radioactivity experienced illness.
Researchers exposed to radioactivity suffered radiation sickness at advanced age.
Manhattan project workers in Los Alamos, Oak Ridge, Hanford, and atomic worker in the former USSR suffered anorexia, fatigue, headache, nausea, vomiting, and diarrhea.
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Radiation Effects
Somatic effects
damages to cells passed on to succeeding cell generations.
damages to cells passed on to succeeding cell generations.
Genetic effects
damages to genes that affect future generations.
Genes are units of hereditary information that occupy fixed positions (locus) on a chromosome. Genes achieve their effects by directing the synthesis of proteins.
damages to genes that affect future generations.
Genes are units of hereditary information that occupy fixed positions (locus) on a chromosome. Genes achieve their effects by directing the synthesis of proteins.
Somatic effects and genetic effects show no immediate symptoms
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Somatic Effects
Damages to cell membranes, mitochondria and cell nuclei result in abnormal cell functions, affecting their division, growth and general heath.
Organs such as skin, lining of gastrointestinal tract, embryos, and bone marrow, whose cells proliferate rapidly are easily damaged.
Bone marrow makes blood, and its damage leads to reduction of blood cell counts and anemia.
Damage to germinal tissues reduces cell division, and induces sterility.
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Genetic Effects
Human cells contain 46 chromosomes. Germ or ovum cells contain 23.
A chromosome contains a deoxyribonucleic acid (DNA) molecule.
The double-helix DNA has two strands of phosphoric-acid and sugar linked bases of Adenine, Guanine Cytosine or Thymine.
The A-T and G-C pairs stack on top of each other.
The DNA codon transcripts mRNA, which directs the amino-acid sequences of protein. DNA Damages result in somatic and genetic effects.
When DNA molecules replicate (pass on to next generation), they are sensitive to radiation damage. Joining wrong ends of broken DNA is called Translocation, which cause mutation and deformation at birth.
Genetic effects increase frequency of mutation.
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How are drilling wastes produced?
The briney solution contained in reservoirs of oil and gas is known as "formation water." During drilling, a mixture of oil, gas, and formation water is pumped to the surface. The water is separated from the oil and gas into tanks or pits, where it is referred to as "produced water." As the oil and gas in the formation are removed, much of what is pumped to the surface is formation water. Consequently, declining oil and gas fields generate more produced water.
209
While uranium and thorium are not soluble in water, their radioactive decay products Help decay products The atoms formed and the energy and particles emitted as radioactive material decays to reach a stable form. such as radium may dissolve in the brine. They may remain in solution or settle out to form sludges that accumulate in tanks and pits, or form mineral scales inside pipes and drilling equipment.
210
How much radioactivity is in the wastes?
Radium levels in the soil and rocks vary greatly, as do their concentrations in scales and sludges. Radiation levels may vary from background soil levels to as high as several hundred picocuries per gram (pCi/g). The variation depends on several factors:
•Concentration and identity of the radionuclides.
•Chemistry of the geologic formation.
•Characteristics of the production process.
211
Waste Types and Amounts
For convention drilling, one industry study published in 2000 (with data from the 1990s)1 showed that the petroleum industry generated around 150,000 cubic meters (260,000 metric tons) of waste per year, including produced water, scales, sludges and contaminated equipment. The amount produced at any one oil play varies and depends on several factors:
•Geological location.
•Formation conditions.
•Type of production operation.
•Age of the production well.
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The volume of wastes from unconventional drilling can be much higher, since the length of the wells through the host formation can be over a mile long.
A 19882 publication estimates that 30 percent of domestic oil and gas wells produced some TENORM. In surveys of production wells in 13 states, the percent reporting high concentrations of radionuclides in the wells ranged from 90 percent in Mississippi to none or only a few in Colorado, South Dakota and Wyoming. However, 20 to 100 percent of the facilities in every state reported some TENORM in heater/treaters. EPA is investigating the number of unconventional wells that are impacted by TENORM.
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Produced Waters
Produced waters are waters pumped from wells and separated from the oil and gas produced. The radioactivity levels in produced waters from unconventional drilling can be significant and the volumes are large. The ratio of produced water to oil in conventional well was approximately 10 barrels of produced water per barrel of oil. According to the American Petroleum Institute (API) , more than 18 billion barrels of waste fluids from oil and gas production are generated annually in the United States.
Produced waters contain levels of radium and its decay products that are concentrated, but the concentrations vary from site to site. In general, produced waters are re-injected into deep wells or are treated for reuse.
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Scale
Scales are normally found on the inside of piping and tubing. API found that the highest concentrations of radioactivity are in the scale in wellhead piping and in production piping near the wellhead. Concentrations were as high as tens of thousands of picocuries per gram. However, the largest volumes of scale occur in three areas:
•Water lines associated with separators, (separate gas from the oil and water).
•Heater treaters (divide the oil and water phases).
•Gas dehydrators, where scale deposits as thick as four inches may accumulate.
215
Chemical scale inhibitors may be applied to the piping complexes to prevent scales from slowing the oil extraction process. If the scales contain TENORM, the radiation will remain in solution and eventually be passed on to the produced waters.
Approximately 100 tons of scale per oil well are generated annually in the United States. As the oil in a reservoir dwindles and more water is pumped out with the oil, the amount of scale increases. In some cases brine is introduced into the formation to enhance recovery; this also increases scale formation.
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The average radium concentration in scale has been estimated to be 480 pCi/g (17.76 becquerels per gram (Bq/g)). It can be much higher (as high as 400,000 pCi/g or 14, 800 Bq/g) or lower depending on regional geology. Scale in gas wells and equipment can also contain the radon progeny lead-210 (Pb-210) and polonium-210 (Po-210)
217
Sludge
Sludge is composed of dissolved solids which precipitate from produced water as its temperature and pressure change. Sludge generally consists of oily, loose material often containing silica compounds, but may also contain large amounts of barium. Dried sludge, with a low oil content, looks and feels similar to soil.
Oil production processes used in conventional drilling generate an estimated 230,000 MT or five million ft3 (141 cubic meters) of TENORM sludge each year. API has determined that most sludge settles out of the production stream and remains in the oil stock and water storage tanks.
218
Like contaminated scale, sludge contains more Ra-226 than Ra-228. The average concentration of radium in sludges is estimated to be 75 pCi/g (2.775 Bq/g). This may vary considerably from site to site. Although the concentration of radiation is lower in sludges than in scales, sludges are more soluble and therefore more readily released to the environment. As a result, they pose a higher risk of exposure.
The concentration of lead-210 (Pb-210) is usually relatively low in hard scales but may be more than 27,000 pCi/g (999 Bq/g) in lead deposits and sludge.
219
Contaminated Equipment
TENORM contamination levels in equipment varied widely among types of equipment and geographic region. The geographic areas with the highest equipment readings were northern Texas and the Gulf Coast crescent from southern Louisiana and Mississippi to the Florida panhandle. Very low levels of TENORM were found in California, Utah, Wyoming, Colorado, and northern Kansas. More recently, unconventional drilling in shale deposits have changed the geographic areas impacted and the amount of contaminated equipment.
220
According to an API industry-wide survey from the 1990s, approximately 64 percent of the gas producing equipment and 57 percent of the oil production equipment showed radioactivity at or near background levels for conventional sites. TENORM radioactivity levels tend to be highest in water handling equipment. Average exposure levels for this equipment were between 30 - 40 microroentgens per hour (μR/hr) (0.0077389- 0.01032 microcoulombs per hour (µC/hr)), which is about five times background. Gas processing equipment with the highest levels include the reflux pumps, propane pumps and tanks, other pumps, and product lines. Average radiation levels for this equipment as between 30 - 70 μR/hr (0.007739- 0.01806 µC/hr). Exposures from some oil production and gas processing equipment exceeded 1 milliroentgen per hour (0.258 µC/hr).
221
Gas plant processing equipment is generally contaminated on the surface and in the internals by lead-210 (Pb-210) and polonium-210 (Po-210). Radon gas is highly mobile. It originates in underground formations and dissolves in the organic petroleum areas of the gas plant. It concentrates mainly in the more volatile propane and ethane fractions of the gas.
Gas plant scales differ from oil production scales, typically consisting of radon decay products which accumulate on the interior surfaces of plant equipment. Radon itself decays quickly, (its half-life is 3.8 days). As a result, the only radionuclides that affect disposal are the radon decay products polonium-210 and lead-210. Polonium-210 is an alpha emitter with a half-life of 140 days. Lead-210 is a weak beta and gamma emitter with a half-life of 22 years.
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