PET Course KFSH&RC Radiation Safety Practices in a Radionuclide Produciton facility v2

1. Radiation Safety Practices in a
Radionuclide Production
Facility
Abdalla N. Al-Haj, PhD, FIPEM, CRadP, CSci, MSRP
Chief Health Physicist
King Faisal Specialist Hospital
& Research Centre

2. INTRODUCTION

3. Do we need radiation
protection?

4. What can radiation do?
Deterministic effects
death, skin burns, cataract,
infertility
Stochastic effects
cancer, genetic effects

5. Ionizing radiation causes both
Deterministic Effects
 effects are manifested after
a threshold dose is exceeded
 severity increases with dose
Stochastic Effects
 probability of effect is proportional
to increments of dose
 no threshold

6. Deterministic effects
Tissue Effect Threshold dose
(Gy)
Ovaries sterility 2.5-6.0
Testicles temporary sterility 0.15
permanent ” 3.5-6.0
Lens cataract 8 Gy for total fractionated
0.5 Gy for lens of eye
Skin erythema 3.0-5.0
necrosis 50

7. Amount of exposure Biological effect
Rate of exposure Biological Effect
Bigger area of exposure More biological effects
Type of radiation :
Quality factor Biological effect
Factors Affecting Biological Effects

8. Short Term Biological Effects
Vary greatly on factors such as:
 amount of exposure
 rate of exposure
 area of body irradiated
 type of radiation
 individual biological variability

9. There are two categories of radiation effects:
Somatic Effects
Effects that are seen on
the irradiated
individual.
Either deterministic or
stochastic.
Genetic Effects
Effects that are seen on
the descendants of the
irradiated individual
as the result of the
lesions on the genes.
They are stochastic .

10. • Deterministic effects
–RP aims to
ELIMINATE them.
• Stochastic effects
–RP aims to REDUCE
them.
AIMS OF RADIATION PROTECTION

11. SYSTEM OF
RADIOLOGICAL PROTECTION

12. How should people be
protected?
• Justify the exposure
• Optimize protection
• Dose /risk limitations
This is the system of radiological protection
as defined by the International Commission
on Radiological Protection (ICRP)

13. Justification
• Justification means that
any dose exposure MUST
have a benefit to exposed
individuals or to society.
• Thus, if the exposure has
no benefit it is not
justified.
Benefits > Risk

14. • Optimization means that
minimum risk and maximum
benefits should be achieved,
economic and social factors
being taken into account.
• Optimization includes the
ALARA criterion: doses
should be “as low as
reasonably achievable”,
economic and social
factors being taken into
account”
2. Optimization

15. ALARA
(as low as reasonably achievable)
Applied to :
• Occupational exposure
• Medical exposure
• Public exposure

16. 3. DOSE/RISK LIMITATION
Protection of individuals by
imposing dose limits or
controlling the risks from
potential exposure

17. Recommended Dose Limits
(Summary)
Applications Occupational Public
Effective dose 20 mSv/year averaged 1 mSv/yr
over defined 5-yr period
Annual
Equivalent Dose:
lens of eye 20 mSv 15 mSv
skin 500 mSv 50 mSv
hands & feet 500 mSv -

18. Radiation safety in
radionuclide production: Why
is there a need?

22. What can go wrong during operation of the
cyclotron?
Potential exposure due to accident or incident during
operation such as:
• Inadvertent strike of particle beam to the internal wall
of the beam tube causing production of high level of
neutrons and γ radiation
• Production of activated materials that will cause high
exposure during grinding, burning and machining.
• Production of Ar-41 in neutron in the vault that can be
inhaled.
• Escape of neutrons and gamma
radiation through shields such
as in vault roof.

23. Pathways associated with Cyclotron incidents
Cyclotron
Target bombardment Inadvertent beam loss
Prompt gamma
Roof
penetration
Prompt neutrons
Shield
penetration
Vault air
activation
Component
activation
Environment
contamination
Radioactive
contamination
Internal
exposure
External
exposure

24. Important for staff protection
Provision of controls:
Engineered controls
Administrative controls
Personal protective equipment (PPE)

25. Important for staff protection
Examples of engineering and administrative controls
Engineering
Shielding of sources
Interlocks on operation of
radiation producing devices
Using sealed enclosures to
reduce exposure or
contamination
Administrative
Remove the worker from the
job if dose is near the limit
Minimize exposure times by
work planning
Use radionuclides in
designated areas using safe
handling techniques
Limit access

26. CLASSIFIED AREAS
Should be defined by the RSO and RSC
Controlled areas:
Supervised areas:
The rest of department
Room for preparation of radiopharmaceuticals
Room for dispensing radiopharmaceuticals
Radionuclide storage room
Storage room for radioactive waste
Room for administration of radiopharmaceuticals
Imaging rooms

27.  Delineate controlled areas by physical means or,
where this is not reasonably practicable, by some
other suitable means
 Display a warning symbol, such as that
recommended by the International Organization for
Standardization (ISO), and appropriate instructions
at access points and other appropriate locations
within controlled areas
CONTROLLED AREA
What to do?

28. Any area in which specific protective measures or
safety provisions are or could be required for:
(a) controlling normal exposures or preventing the
spread of contamination during normal working
conditions
(b) preventing or limiting the extent of potential
exposures.
Controlled areas

29.  Establish occupational protection and safety
measures, including local rules and procedures
that are appropriate for controlled areas
 Permit to perform maintenance and repair
 Evaluation of work and hazards associated with
work.
 Restrict access to controlled areas by means of
administrative procedures, such as the use of work
permits, and by physical barriers, which could
include locks or interlocks; the degree of restriction
being commensurate with the magnitude and
likelihood of the expected exposures.

30.  Provide, as appropriate, at entrances to controlled
areas:
• protective clothing and equipment;
• monitoring equipment
• suitable storage for personal clothing
 Provide, as appropriate, at exits from controlled
areas:
• equipment for monitoring for contamination
of skin and clothing;
• equipment for monitoring for contamination
of any object or substance being removed
from the area
• washing or showering facilities
• suitable storage for contamination and
protective clothing and equipment

31.  Periodically review conditions to determine the
possible need to revise the protection measures or
safety provisions, or the boundaries of controlled
areas.

32. Any area not already designated as a controlled area but
where occupational exposure conditions need to be kept
under review even though specific protection measures
and safety provisions are not normally needed.
Registrants and licensees shall, taking into account the
nature and extent of radiation hazards in the supervised
areas:
(a) delineate the supervised areas by appropriate
means
(b) display approved signs at appropriate access
points to supervised areas
(c) periodically review the conditions to determine any
need for protective measures and safety provisions
or changes to the boundaries of supervised areas.
SUPERVISED AREA

33. Protection of
Radiation Workers

34. Sources of Exposure of the Worker
• Packing radioactive material
• Activity measurements
• Storage of sources
• Internal transport of sources
• Preparation of radiopharmaceuticals
• Cyclotron maintenance
• Research
• Handling of radioactive waste
• Accidents
External Exposure

35. Internal Exposure
• Inhalation
• Ingestion
• Through skin (wounds,etc)
This happens when working with
volatile radioisotopes.
Sources of Exposure of the Worker

36. Radiation Safety Culture: observe
the radation protection principles
Time - longer time higher exposure
Reduce time in contact with
radiation sources
Training on a particular task using
non-radioactive dummy sources
Distance- follows the inverse square law
Steeping back can reduce the
exposure by a factor of 2
Use long tweezers for handling
radioisotopes.

37. Radiation Safety Culture: observe
the radiation protection principles
Shielding - use lead shields
Containment of contamination use
absorbent pads

38. UNSHIELDED SYRINGES
 Should be handled by the end remote from
the needle.
 Use of syringes with capacity greater than the
volume to be transferred (e.g. 5 ml for an
injection volume of less than 2 ml).
 Syringes should not normally be filled to
more than 50% of their capacity.

39. Radiation Safety Culture:
Use personal protective equipment
Sources of contamination
• Preparation and packing of
radiopharmaceuticals
• spills
• Handling of emergencies
protective clothing
protective aprons
gloves

40. • It is important to prevent hand contamination
not only from radiation safety standpoint but
also to minimize transferring the
contamination to equipment and to test tube
sample.
• It provides some reduction in beta dose (20-
30% reduction given by surgical gloves).
• Laboratory coat protects the clothing from
accidental splashing.
Use protective clothing (disposable
plastic and laboratory coat)

42. Radiation safety Culture: Use
designated counter tops
Workbench tops should be constructed of stainless
steel with flanged edges to confine accidental spills
and permit easy decontamination.
Work surface should be covered with a plastic-
backed absorbent material to protect the surface
from contamination.
Use trays and absorbent plastic-backed paper at work
areas. If contamination occurs, the tray or paper can
readily be replaced.

43. Radation safety culture: Use
designated sinks
Sinks are necessary for washing contaminated
glassware and for disposal of small quantities of
radioactive solution. [Do not exceed the disposal
limit set by the regulation.]
Should be deep-well type to minimize splashing
for surrounding areas.
Radioactive sign shall be posted for “Hot sink”

44. Radiation safety culture: Use Hoods
The type of hood will depend on the nature of the
work to be performed.
Chemical exhaust hood (fumehood)
• It is used if the work does not require a sterile
air environment.
• It is necessary for work involving radioiodine
and other volatile radioisotopes.

45. Laminar airflow hood
• It is the most suitable for applications
that may require sterile air environment
such as certain labeling procedures (
blood cell and protein labeling).
• The room air is filtered (Hepa filter with
99.9% efficiency) before it enters the
work space of the hood.

46. Radiation safety culture: Manage Radioactive
Wastes
 Use designated containers for
radioactive wastes
 Segregate waste (solid, liquid, gas)
 Tag the plastic bag with waste
Identify the radioisotopes
Indicate the date of collection
Indicate the exposure rate
readings
 Deliver to storage area
 Do not leave radioactive wastes
unattended in hallways
Proper management of radioactive waste
protects both the radiation workers and the
members of public.

47. Radation safety culture:
Individual dose monitoring
• for all those who are occupationally
exposed unless it is clear that their
doses will be consistently low
• to confirm the classification of work
places
• to detect fluctuations in working
conditions
• to give useful reassurance
• to provide data for reviewing
optimization programmes

48. Personal Radation dose Monitoring
Use the personal dose monitor whenever there is a
possibility of radiation exposure.
Do not borrow personal dose monitors.
Report when lost.
Whole body badges
Ring badges

49. WHOLE BODY MONITORING
(contamination)
The gamma camera
without collimator can
be used
Body frisking

50. Thyroid monitoring should be done
for increased uptake of I-131
Monitoring for Internal Exposure

51. Intervention for Personnel Dose
Monitoring
Investigation is conducted when:
 the individual annual effective dose
exceeds the investigation level
 any of the operational parameters subject to
periodic quality control are out of the normal
range established for operational conditions
 any severe accident or error takes place
 any other event or unusual circumstance that
causes, or has potential to cause a dose in
excess of the regulatory limits.

52. Pregnant Workers
Occupational exposed female staff should notify the RPO/licensee of
pregnancy as soon as possible.
A prescribed dose constraint should
be readily achievable provided
licensees maintain appropriate
protection standards and both staff
and management have a sound safety
culture. The contamination risk
should be considered.

53. Radiation safety culture: Workplace
monitoring for radation level and
contamination
• Quantities to be measured
• Where and when the measurements will
be done
• Frequency of measurements
• Reference levels and actions to be taken
if they are exceeded.

54. Surface Contamination
• Loose contamination -when the radioactive
material deposited on surfaces can be easily
removed by simple decontamination
methods
• Fixed contamination -when the radioactive
material can not be removed by simple
methods ( e.g. contamination on skin with
abrasion)

55. Measuring Surface Contamination
• Direct Method - using an end-window GM
survey meter with about 1 inch diameter
detector
• Wipe test over a 100 cm2 area and using a
scintillation counter for reading.

56. Radiation Accidents and Incidents
Contamination and exposure (gamma) in
handling unsealed sources.
Discharge of radioactive substances to the
environment (liquid or gas effluents)
Risks

57. Accidents or Incidents

58. Response to radiation incidents or accidents

59. Develop an emergency plan
consisting of :

60. Develop an emergency plan
consisting of:

62. Verification of Safety
• Safety assessments
 Engineering controls
 Adminstrative controls
 Personnel protective equipment
 Hazard evaluation
• Monitoring and verification of compliance
 Radiaton Safety manual
 Radiation Safety Program
• Records and Documents

63. SAFETY ASSESSMENT BEFORE
COMMENCEMENT OF WORK
Dose mapping before start of work
Expected individual dose and contamination
level
Protective equipment to be used
Dose/time restrictions
Waste management
When to contact the Radiation Safety Officer

64. MANAGEMENT REQUIREMENTS
FOR DOSE REDUCTION
• Safety Culture
• Quality Assurance
• Human Factors
• Qualified Staff