1. University of Notre Dame
Department of Risk Management and Safety
Radiation Safety
Training

2. Lesson 1 Forms of Radiation

3. Forms of Ionizing Radiation
Ionizing radiation includes emissions with energies greater than 20 electron volts that cause ionizations when interacting with matter.
Sources of ionizing radiation at Notre Dame include:
Photon Radiation
Gamma
X-Ray
Particulate Radiation
Alpha
Beta

4. Particulate Radiation
ALPHA RADIATION
Consists of two protons and two neutrons (helium nucleus)
Massive size, moving at 80% the speed of light
Internal Hazard
BETA RADIATION
Consists of an electron
Very small size moving at up to 99% the speed of light
Hazard depends on decay energy of isotope

5. Bremsstrahlung Radiation
Literally: breaking radiation
Electromagnetic radiation produced when an electrically charged particle is slowed down by the electric field of an atomic nucleus
Example: The beta particle emitted by a P-32 atom will interact with lead to give off an x-ray
Bremsstrahlung production must be considered when planning the shielding of high energy beta emitters e-
X-ray

6. Lesson 2 Units of Radiation

7. Units of Radiation
RAD
The RAD is the unit commonly used in the United States for Absorbed Dose (D)
It is determined by the Energy that is actually deposited in matter
1 Rad = 100 ergs of deposited energy per gram of absorber
Gray
International Unit for Absorbed Dose
1 Gray = 100 Rads

8. Units of Radiation
REM
The REM is the unit commonly used in the United States for the Dose Equivalent
Determined by Multiplying the absorbed dose (D) times a quality factor (Q)
Q equals 1 for beta, gamma and x-rays,
5-20 for neutrons, and 20 for alpha
Sievert
International Unit for absorbed dose
1 Sievert = 100 REM

9. Units of Radiation
Most labs at Notre Dame will use only beta, gamma and/or x-ray emitters
The Quality factor for these forms of radiation is equal to 1
Therefore the Rad is equal to the Rem
If your lab is one of the few using alpha, remember that the QF is 20. Therefore, one Rad of alpha is equal to 20 Rem.
Exposure reports are documented in mREM
1 REM = 1,000 mREM

10. Lesson 3 Biological Effects & Risk

11. Biological Effects
Data is largely based on high exposures to individuals within the first half of the 20th century
Biological effects occur when exposure to radiation exceeds 50 rads over a short period of time
All occupational exposures are limited by city, state, or federal regulations

12. Radiation Damage Mechanical: Direct hit to the DNA by the radiation
- Damages cells by breaking the DNA bonds
Chemical: Generates peroxides which can attack the DNA
Damage can be repaired for small amounts of exposure

13. Radiosensitivity Muscle Radioresistant Stomach Radiosensitive
Bone Marrow Radiosensitive
Human Gonads Very Radiosensitive

14. Radiation Effects
Acute Effects: Nausea, Vomiting, Reddening of Skin, Hair Loss, Blood Changes
Latent Effects: Cataracts, Genetic effects, Cancer

15. Lesson 4 Occupational Exposure

16. What are the Occupational Exposure Limits ?
Whole Body
Extremities
Skin of Whole Body
Lens of Eye
Thyroid
5,000 mRem/year
50,000 mRem/year
15,000 mRem/year

17. Other Occupational Limits
ALARA - As Low As Reasonably Achievable. This is our policy AND the NRC’s: Don’t expose yourself to radiation any more than absolutely necessary.

18. Exposure to the General Public
Annual limit of 100 mRem to individuals
This includes anybody in the laboratory who does not work for Notre Dame
Examples: salesmen, vendors, family members, etc.

19. Prenatal Radiation Exposure
In the embryo stage, cells are dividing very rapidly and are undifferentiated in their structure and are more sensitive to radiation exposure
Especially sensitive during the first 2 to 3 months after conception
This sensitivity increases the risk of cancer and retardation

20. Declaring Pregnancy
Additional dose restrictions are available for the pregnant worker
Receive a monthly dosimeter
Limited to 500 mRem during the term of the pregnancy
Also, limited to 50 mRem per month
DECLARATION IS STRICTLY OPTIONAL

21. Exposure to Minors Individuals under the age of 18
Must not receive an exposure greater than 10% of occupational exposure for adults
Wholebody Exposure Limit: 500 mRem
Minors will wear dosimeters in laboratories licensed for radioactive material use
Minors should not work with radioactive material

22. Lesson 5 Minimizing Exposure

23. How Do I Protect Myself?
Reducing the dose from any source radiation exposure involves the use of three protective measures:
TIME
DISTANCE
SHIELDING

24. Time
The amount of exposure an individual accumulates is directly proportional to the time of exposure
Keep handling time to a minimum

25. Distance
The relationship between distance and exposure follows the inverse square law. The intensity of the radiation exposure decreases in proportion to the inverse of the distance squared
Dose2 = Dose1 x (d1/d2)2

26. Shielding
To shield against beta emissions, use plexiglass to decrease the production of bremsstrahlung radiation.
If necessary, supplement with lead after the plexiglass
To shield against gamma and x-rays, use lead, leaded glass or leaded plastic

27. Internal Exposure
Only a few commonly used radionuclides at Notre Dame present an external exposure potential
All radionuclides present a potential for internal exposure if taken into the body. Entry into the body can occur by inhalation, ingestion, or absorption through the skin

28. Minimizing Internal Exposure
Wear personal protective equipment
If required, use a fume hood
No eating, drinking or applying cosmetics
Clean up spills promptly
Routinely monitor work area
Secure radioactive material

29. Minimum Protective Equipment
Laboratory coat
Gloves
Safety Glasses
Dosimeters (for certain nuclides and/or machines)

30. Lesson 6 Radiation Detection

31. Detecting Radiation and Contamination
Personal dosimeters are used to detect the occupational exposure to employees from external sources of radiation
A survey meter may be used to detect large quantities of high energy beta and gamma emitters on a surface
For smaller quantities of contamination on surfaces and low energy beta emitters, use the wipe test method

32. Film Badge
Required when there is a possibility of receiving greater than 10% of exposure limit
Monitors for gamma, x-ray and high energy beta
Worn for 2 months
These are individual specific - Do not loan out
Return promptly after receiving a new one

33. Ring Dosimeter Monitors exposure to the hands
Used for high energy beta, gamma and x-ray radiation
Worn when handling sources like those listed above or x-ray machines
Worn underneath the protective glove

34. Survey Instruments Geiger Mueller (G-M)
- Detects alpha, beta, and gamma radiation
- Best option for detecting beta contamination
Sodium Iodide Detector
- Gamma and x-ray only

35. Survey Instruments Operational Check Check calibration date
Confirm calibration date within past year
Check batteries
Check response to radioactive source to confirm that the meter is operational

36. Survey Instruments Geiger-Mueller Detector Sodium-Iodine Detector
Used for beta, gamma and x-ray emitters
Best for P-32, S-35 and C-14
Will detect I-125 and Cr-51
Sodium-Iodine Detector
Detects gamma and x-ray emitters
I-125 and Cr-51
Do not use to detect beta emitters

37. Wipe Test Method
The Wipe Test Method is a means of monitoring for small amounts of contamination
It is the only method in the lab for detecting H-3
Wipe test surveys should include both areas where contamination is expected to be found and areas where it is not expected

38. Wipe Test Choose equipment and surfaces to wipe
Use a filter paper or Q-tip to wipe approximately 100 cm2.
Place filter paper or Q-tip in scintillation vial and add scintillation fluid (use enough fluid to fill at least ½ of vial)
Place sample in scintillation counter
Set scintillation counter to detect radioisotopes used in laboratory
Include a standard or sample containing a known amount of radioactive material
Include a background or control sample

39. Determining Activity of Wipes
If the scintillation counter only provides results in counts per minute (cpm) it will be necessary to convert those results to disintegrations per minute (dpm). This can be done by including a control sample with your wipes that contains the isotope of interest.
dpm = cpm / counting efficiency
Standard (cpm) / Standard (dpm) = Efficiency
1 uCi = 2.22 X 106 dpm
Decay of the standard’s activity must be considered.

40. Lesson 7 Contamination Control

41. Contamination
Definition: Radioactive material in an undesired location
Undesired
locations: Surfaces, skin, internal, airborne
Types: Removable – Decontamination is possible
Fixed – Unable to decontaminate

42. Contamination Limits <20 dpm/100cm2 a in restricted areas
<1,000 dpm/100cm2 b/g in restricted areas (radioisotope laboratories)
>1,000 dpm/100cm2 b/g immediately clean up to below 1,000 dpm/100cm2

43. Contamination Control
Work in areas designated for radioactive material
Use absorbent pads
Wear appropriate protective clothing
Change gloves frequently
Perform a dry run of the procedure without radioactive materials
It is recommend that you set up well-defined, clearly labeled radioactive material work stations and restrict radioactive materials use to those areas

44. Spill Response Notify people working in the laboratory
Control access to the affected area
Wear gloves, lab coat, and safety glasses
Clean spill from the outer perimeter inward
Avoid spattering and generating aerosols
After initial clean up, monitor for contamination
Repeat process if contamination remains
Call the RSO (1-5037) if you need help or if the spill is greater than 100 µCi

45. Decontamination of Skin
If the radioactive material is a high energy beta, gamma, or x-ray emitter, monitor with a survey meter and record reading
Gently wash the affected area for 15 minutes with lukewarm water and a mild soap
If you continue to find contamination, repeat washing and monitoring for up to 3 times
Record final survey meter readings
Contact Radiation Safety at

46. Lesson 8 Radioactive Waste

47. Radioactive Waste Disposal
Minimize generation of waste
Identify and segregate dry solid waste
- long lived (H-3 and C-14)
- - short lived (P-32 and S-35)
Complete a waste form for pickup
Keep disposal records

48. Do Not Mix Waste Types
Do not place scintillation vials into dry solid waste containers
Do not place dry solid waste into liquid scintillation vial waste
Do not place liquid waste container into dry solid waste containers
DO NOT MIX LONG AND SHORT HALF-LIVED WASTE (Break point = 89 days)

49. Holding Radioactive Waste for Decay
Provide appropriate shielding for the waste
Seal the container to prevent individuals from adding to the waste
Label the waste container with the isotope, amount of radioactive material, and date the container was sealed
Hold for 10 half-lives. This will be done by RM&S.

50. Radioactive Waste Containers
DO NOT dispose of radioactive waste in:
- medical waste
containers
- general waste
Use only approved radioactive waste containers supplied by Radiation Safety which contains a warning label “Caution Radioactive Material”

51. Scintillation Vials
Place in a separate container from the dry solid radioactive waste
Separate scintillation vials containing long lived isotopes
(H-3 and C-14) from those containing shorter lived isotopes (P-32, I-125)
Ensure the lids are secured tightly on the bottles
Do not overfill the container
Complete a Radioactive Waste Form

52. Contaminated Sharps Syringes Pasteur Pipettes Scalpel Needles
Radioactive sharps must be segregated from other radioactive waste and placed in a radioactive materials labeled sharps container.

53. Collecting Liquid Use a durable carboy from RM&S
Attach a radiation warning label to the bottle
Document the isotope, activity and date on the container
Secure the lid on the container at all times
NEVER POWER IT DOWN THE LAB SINK

54. Lesson 9 Clearing Equipment

55. Clearing Equipment For repair by Engineering or Vendor:
Ensure equipment is empty of all samples, containers, and radioactive material
Conduct wipe test and present results to RSO
Monitor with survey meter
Decontaminate equipment if required

56. Telephone Numbers Radiation Safety: 1-5037 Fax: 1-8794
Risk Management & Safety website:
After hours, weekends, holidays: Call ND Security