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Radiation Safety Training ALARA Washington State University Radiation Safety Office

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Polonium-210 is an alpha emitter. As we have seen in another module, alpha radiation is the highest internal hazard. If Mr. Litvinenko had not ingested the polonium ... – PowerPoint PPT presentation

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Title: Radiation Safety Training ALARA Washington State University Radiation Safety Office


1
Radiation Safety TrainingALARAWashington
State UniversityRadiation Safety Office
2
The Guiding Principle and Philosophy of Radiation
Safety is
  • ALARA
  • (As Low As Reasonably Achievable)
  • It is also a regulatory requirement!

3
So what does ALARA mean ?
  • ALARA is an acronym for As Low As Reasonably
    Achievable. This is a radiation safety principle
    for minimizing radiation doses and releases of
    radioactive materials by employing all reasonable
    methods.
  • ALARA is not only a sound safety principle,
    but it is also a regulatory requirement for all
    radiation safety programs.

4
What is the basis for ALARA ?
  • Current radiation safety philosophy is based
    on
  • the conservative assumption that radiation dose
  • and its biological effects on living tissues are
  • modeled by a relationship known as the Linear
  • Hypothesis.
  • The assertion is that every radiation dose of
    any
  • magnitude can produce some level of detrimental
  • effects which may be manifested as an increased
  • risk of Genetic mutations and cancer.

5
RADIATION DOSE/RESPONSE MODELS
  • Two models (1) Linear 2) Threshold
  • Preferred (Regulatory) model is Linear
    No-Threshold Dose Model
  • Conservative Hypothesis - For any dose, no matter
    how small, there is some effect, and as the dose
    is increased, the effect also is increased in
    proportion.

Biological Response
Biological Response
Dose
Dose
Threshold
6
How is ALARA Implemented ?
  • An effective ALARA program is only possible when
    a
  • commitment to safety is made by all those
    involved. This
  • includes the Radiation Safety Office staff, the
  • Radiation Safety Committee, research faculty and
    all
  • radiation workers. The WSU Radiation Protection
  • Program Manual provides the guidelines for the
  • Responsibilities and good practices which are
    consistent
  • with both the ALARA concept and the regulatory
  • requirements of the Washington State
    Administrative
  • Code (Title 246 Chapter 220-254).

7
WSU radiation safety program.
  • The WSU radiation safety program attempts to
    lower doses received by radiation workers by
    utilizing practical, cost effective measures.

8
How do we do this?
9
With the 4 basic Radiation Protection
Principles.
  • Time
  • Distance
  • Shielding
  • Contamination Control

10
TIME EXPOSURE
Decreasing the amount of time near the source
decreases your exposure.
11
How do you decrease your time exposure?
  • Plan and Set Up Your Experiment Before Using
    Radioactive Materials.
  • Perform Dry Runs - (Use NO Radioactive Material).
  • Practice Handling Techniques (pipetting/aliquottin
    g).
  • Work Quickly but Safely.

12
DISTANCEEXPOSURE
Increasing the distance from the source decreases
your exposure.
13
Increasing the distance from a source from 3
feet to 10 feet reduces the radiation intensity
by 91.Increasing the distance from a source
from 3 feet to 32 feet reduces the radiation
intensity by 99.9912. Increasing the distance
from a source from 3 feet to 60 feet reduces the
radiation intensity by 99.9975.
Attenuation of Radiation Intensity with Distance
14
Inverse Square Law 1/(distance)2
If you double the distance from a point source of
radiation, the exposure is reduced to ¼ the
intensity at the closer distance.
  • ---------------------- I1 (100 mR/hr)
  • D1 (1 meters)
  • --------------------------------------------------
    ------------------ I2(?)
  • D2 (8 meters)
  • Given I1 100 mR/hr
  • D1 1 meters
  • D2 8 meters
  • I2 (d1)2 X I1
  • (d2)2
  • 1.6 mR/hr

15
SHIELDINGEXPOSURE
Increasing the amount of shielding decreases
your exposure.
16
Proper thickness and appropriate materials are
critical to shield you from a radiation hazard.
Shielding Examples
17
SHIELDING
  • Appropriate Shielding
  • High "Z" Materials (Pb) for photons
  • Low "Z" Materials (Acrylic or Plexiglas) for beta
    radiation
  • Using Storage Containers (pigs)
  • Shipping Containers from RAM
  • Suppliers
  • Using Local Shielding (Plexiglas
    L-Blocks Pb - Bricks)
  • Using Vial Syringe Shields
  • Balance between shielding and time. (If it
    takes a long time to
  • insert RAM into a shield it may not
    be ALARA!)

18
CONTROLLING EXTERNAL HAZARD
  • TIME Radiation dose is proportional to the
  • duration of the exposure.
  • DISTANCE Radiation dose is proportional
    to 1/(Distance)2.
  • SHIELDING Radiation dose is determined by
  • the type and thickness of shielding materials
    used.
  • Correct selection of Shielding Materials
  • are a function of type and energy of radiation.

19
So how do we control the internal hazard?
20
By Contamination Control
  • The major hazard for most radioactive materials
    on the WSU campus comes from internalizing the
    radioactive material.
  • Once the radioactive materials are inside your
    body, you lose all the protections from TIME,
    DISTANCE AND SHIELDING.
  • Contamination Control is the key to preventing
    internalization of radioactive materials.

21
Radionuclides can enter thebody in four ways.
Inhalation, ingestion, absorption through the
skin and wounds.
22
Contamination Control
  • Protect Yourself
  • Always use protective clothing.
  • Lab Coat
  • Gloves
  • Eyewear
  • Required by WAC 246-235-130

Wear gloves properly.
Lab Coats can be very fashionable. But always
wear long pants and full shoes. The hat is
optional.
Dont dress like this guy!
23
CONTAMINATION CONTROL
  • Always WEAR your lab coat and gloves, including
    appropriate leg and foot covering.
  • Required by WAC 246-235-130
  • Wear safety
    glasses/goggles or a face shield
  • when working with
    unsealed RAM. These
  • precautions are
    especially important when
  • there is a splash
    potential.

24
CONTAMINATION CONTROL (continued)
  • CHANGE gloves frequently and REMOVE
  • them when leaving the lab and dispose of
  • them as radioactive waste. To control cross
  • contamination of yourself, others and
  • other research items.

25
Protect Others
  • If you contaminate your lab partners. They will
    not be happy with you.
  • Label your radioactive work area.

Required by WAC 246-235-130
26
Protect Others (cont.)
  • Label containers and tools used in radioactive
    work.

Required by WAC 246-235-130
27
Contamination Control (cont.)
  • Protect Facilities and Equipment
  • Cover all radioactive work areas
  • with absorbent paper, including
  • any transfer trays or secondary
  • containers.
  • Required by WAC 246-235-130

Tape off the work area.
Check for Contamination (do surveys)
28
CONTAMINATION CONTROL (continued)
  • Store and transport liquid radioactive materials
    in SECONDARY CONTAINERS, with the capacity to
    contain potential spills.
  • USE DOUBLE CONTAINMENT

29
FOOD and DRINK
  • NO eating, drinking, smoking, or chewing in the
    radioactive work space. (Internal
    contamination)
  • Do not store food, drink or personal effects in
    any area, container, or refrigerator designated
    for radioactive materials use or storage.
    Required by WAC 246-235-130
  • The presence of
    empty food and drink
  • containers in
    the lab will constitute
  • a violation
    of regulations, since it will
  • be inferred
    that consumption occurred
  • on the
    premises.

30
CONTAMINATION CONTROL (continued)
  • NO mouth pipetting.
    (Internal contamination)
  • Required by WAC 246-235-130
  • MONITOR hands, clothes and work
    area
  • frequently during and after each use.
  • Always WASH hands
  • at the completion of
  • radioactive work.

31
ADDITIONAL RADIATION SAFETY PRECAUTIONS
  • Work with volatile compounds in a CERTIFIED
    OPERATIONAL fume hood. The hood must also be
    labeled for radioactive materials use.
  • - Operational parameters of
    the fume hood
  • must be verified before
    you begin your
  • radioactive work.

32
CONTROLLING INTERNAL HAZARD
  • To minimize the uptake of radionuclides into the
    body
  • control the Routes of Entry
  • Inhalation Use of fume hood, gloved boxes.
  • Gases and vapors in experiments.
  • Radioactive spill of volatile compounds.
  • Opening of sealed vials.
  • Ingestion No eating, drinking, chewing, smoking
    or
  • application of cosmetics in radioactive
    laboratories.
  • Use of gloves (preferably double gloves).
  • No food in radioactive refrigerators.
  • Washing hands, do monitoring.
  • Prohibit mouth pipetting.
  • Absorption Wear protective clothing (lab coat,
    full shoes be aware of loose sleeves of lab
    coat).

33
On November 1, 2006, Alexander Litvinenko
suddenly fell ill and was hospitalized.
34
He died three weeks later of polonium-210 induced
acute radiation syndrome. The median lethal dose
for polonium-210 is around 238 µCi or
50 nanograms in the case of ingestion. The
polonium-210 was in his tea.
35
Keep radioactive materials out of your body.
  • Polonium-210 is an alpha emitter. As we have
    seen in another module, alpha radiation is the
    highest internal hazard. If Mr. Litvinenko had
    not ingested the polonium it would not have been
    a radioactive hazard to him. The alpha radiation
    emitted by the polonium would not have penetrated
    the layer of dead skin on his body.
  • So keep your lab clean. Do your
    surveys.
  • NO eating, drinking, smoking, or chewing
  • in the radioactive work space.
  • Do not store food, drink or personal
  • effects in any area, container, or
  • refrigerator designated for radioactive
  • materials use or storage.

36
Test Time!
  • Follow this link to the test. https//myresearch.w
    su.edu
  • Use your WSU user name and password to sign in.
  • Click on the training tab.
  • Then click on the available training tab
  • Find the radiation safety training alara course,
    in the OR section, click on it and take the test.
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