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Radiation MeasurementRadiation Measurement
Terminology:
– Exposure rate = amount radiation possible to receive per unit time.
– Dose = total amount of radiation received.
2. Berdasarkan dosis radiasia..E fek Stokastik Efek terjadi sebagai akibat paparan radiasi dengan dosis
yang menyebabkan terjadinya perubahan pada sel. Tidak mengenal dosis ambang Timbul setelah melalui masa tenang yang lama &
Keparahannya tidak bergantung pada dosis radiasi Tidak ada penyembuhan spontan Efek ini meliputi : kanker, leukemia (efek somatik), dan
penyakit keturunan (efek genetik).
b. Efek Deterministik (non-stokastik) adalah efek yang kualitas keparahannya bervariasi menurut dosis dan hanya timbul bila dosis ambang dilampaui.
Mempunyai dosis ambang .timbul beberapa saat setelah radiasi
Adanya penyembuhan spontan (tergantung keparahan) & Tingkat keparahan tergantung terhadap dosis radiasi
Efek ini meliputi : luka bakar, sterilitas / kemandulan, katarak (efek somatik)
Radiation and Radioactivity: Radiation and Radioactivity: Units and QuantitiesUnits and Quantities
Department of HealthBureau of Radiation Control
Introduction Introduction
Quantities (mass, volume, time, etc.) vs. Units (grams, gallons, hours)
Units of exposure, radioactivity, and energy associated with ionizing radioactivity
As hours and minutes are to time ...
ObjectivesObjectives
Define – ROENTGEN, RAD, REM, CURIE, GRAY,
SIEVERT, BECQUEREL.– SI units vs. Standard English units
Discuss the use and conversion of unit prefixes
Transform units using “unit analysis”
Background Background
Early risk associated with use of ionizing radiation
skin erythema dose - 25yrs1928 - ROENTGEN introduced by ICRP
RoentgenRoentgen
RoentgenRoentgen
Pronounced rent’gen with a hard “g”Limitations
– only applies to photons– only applies in air– only applies to energies less than 3 MeV
Named after Wilhelm C. Roentgen (thus the abbr... is capital “R”)
radrad
radrad1 rad = 1 Roentgen
remrem
remrem
The unit of dose equivalent for any type of ionizing radiation absorbed by body tissue in terms of estimated biological effect - Unit of dose equivalent
Dose in health record is in units of rem1 rem = 1 Roentgen
Roentgen Equivalent Man
Quality Factor (Q)Quality Factor (Q)
The specific value that accounts for the ability of different types of ionizing radiation to cause varying degrees of biological damage– X-rays, gamma rays, & beta particles 1– Neutrons & High energy protons 10– Alpha Particles 20
Curie (Ci)Curie (Ci)
Radiation hazard does not solely depend on the activity. It also depends on the type of decay (alpha, beta, photon, etc.)
Named in honor of Pierre Curie
SI Radiation Protection UnitsSI Radiation Protection Units
Becquerel (Bq) for Curie– 1 Ci = 3.7 x 1010 Bq
Gray (Gy) for rad– 1 Gy = 100 rad
Sievert (Sv) for rem– 1 Sv = 100 rem
Unit AnalysisUnit Analysis
BASE UNIT CONVERSION TABLE
Unit Unit Conversion1 Bq 2.7 x 10-11 Ci1 Ci 3.7 x 1010 Bq
1 Bq 1 dis/sec1 dis/sec 2.7 x 10-11 Ci1 Ci 3.7 x 1010 dis/sec
Unit Analysis (Con’t.)Unit Analysis (Con’t.)BASE UNIT CONVERSION TABLE
Unit Unit Conversion
1 rem 0.01 Sv1 Sv 100 rem1 rad 0.01 Gy1 Gy 100 rad1 R 2.58 x 10-4 C/kg1 meter 3.28 ft (39.37in)
SummarySummary
Radiation Protection unit definitions (including SI units)
Unit PrefixesUnit conversions
New Terms New Terms sort ofsort of
International Units have replaced the RAD and REM
GRAY (Gy) = 100 RADSIEVERT (Sv) = 100 REM
Same Quality Factors apply to the Sv
Units of RadioactivityUnits of Radioactivity
Curie (Ci) = 2.22 E12 dpm or 3.7E10 dpsBecquerel (Bq) = 1 dpsMaximum Dose/year = 5 REM or 50 mSvMaximum Dose/year for Declared Pregnant
Woman & Minors= 0.5 REM or 5 mSv
Annual Dose LimitsAnnual Dose LimitsExternal/Internal Exposure Limits for Occupationally Exposed Individuals
Adult ($18 yrs) Minor (< 18 yrs)
Whole body* 5000 mrem/yr 500 mrem/yr
Lens of eye 15000 mrem/yr
1500 mrem/yr
Extremities 50000 mrem/yr
5000 mrem/yr
Skin 50000 mrem/yr
5000 mrem/yr
Organ 50000 mrem/yr
5000 mrem/yr
*Effective dose equivalent
Dose Response RelationshipsDose Response Relationships
0-150 rem—No or minimal symptoms150-400 rem—Moderate to severe illness400-800 rem—Severe illness deaths start
above 500 remAbove 800 rem—Fatal
***Acute whole body doses
Your Annual ExposureYour Annual ExposureActivity Typical DoseSmoking 280 millirem/year
Radioactive materials use in a UM lab <10 millirem/year
Dental x-ray 10 millirem per x-ray
Chest x-ray 8 millirem per x-ray
Drinking water 5 millirem/yearCross country round trip by air 5 millirem per trip
Coal Burning power plant 0.165 millirem/year
Estimated Exposure To The Estimated Exposure To The National PopulationNational Population
Between 320 – 360 mr/yr
Another Look at SourcesAnother Look at Sources
Some Exposure LimitsSome Exposure Limits 2 mr/hr Dose rate to public / Federal 500 mr Emergency responder limit / State/BRC 5 r/yr Occupational /Federal 5 r/hr Turn back value / State/BRC 10 r Property / Federal 25 r Life saving / Federal >25r Volunteers only / Federal
Ref - 10CFR PART 20, EPA 400, FL-SOP
Security Security
All Radioactive Materials must be secured or under direct supervision at all times
There MUST be someone in the room at all times OR the door must be locked.
Spill ResponseSpill Response
On Skin—flush completelyOn Clothing—removeIf Injury—administer first aidRadioactive Gas Release—vacate area,
shut off fans, post warningMonitor all persons and define the area of
contamination
ALARAALARA
As Low As Reasonably Achievable—means making every reasonable effort to maintain exposures to radiation as far below the dose limits as is practicable consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to the state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations, and in relation to utilization of nuclear energy and licensed materials in the public interest.