1. Industrial Radiography Basic Safety Requirements
Day 5 – Lecture 6

2. Contents Compound Radiography - Design of enclosure
- Effective engineering controls
Equipment Maintenance
Site Radiography Procedures

3. ALARA Radiation exposures to be kept As Low As Reasonably Achievable.
Where practicable, to be achieved by
means of engineered controls

4. Compounds (fixed facilities)
Enclosure design
Control of exposure

5. Typical design warning lights goods access door emergency cut-out door
maze
entrance
General design:
1. Shielding
- from direct beam and scatter
- Air scatter (sky-shine) in compounds with minimal/no roofing
- penetration of shielding required (eg, ventilation and cable ducts )
2. personnel access door interlocks
3. fixed radiation monitors (gamma work)
4. warning signs and notices
5. emergency stops
6. maze entrances
door
control panel

6. Control of exposure Safety systems to prevent access during exposure :
door interlocks
fixed radiation monitors (gamma work)
emergency stops
Discuss types of features and devices - text on a reveal
Describe maintenance and testing regimes

7. Door Interlocks
Door interlock

8. Door Interlocks Fail to safety Not easily defeated
Easy to operate if frequent access required
Guarded interlocks to prevent tampering

9. Emergency stop

10. Emergency stops button/wire
located so it can be reached without passing primary beam
adequately labelled
Discuss types of features and devices - text on a reveal
Describe maintenance and testing regimes

11. Warning notice
A warning light, which illuminates during exposure and is clearly visible from
outside the radiation source room, must be provided at access points to the
radiation source room.
If the radiation source room is a fully enclosed site, it must be provided with
visible and audible warning devices inside the radiation source room which
activate during exposure.
If the radiation source room is a partially enclosed site, it must be provided with
visible and audible warning devices which activate during exposure and which
can be seen and heard from both inside and outside the radiation source room

12. Warning devices Pre-exposure signal (whistle, klaxon)
Source exposure warning light (flashing)
Notices explaining the meaning of the signals and actions to be taken
- local language
- inside and outside the compound
The entrance to the radiation source room must have:
(a) a radiation warning sign which illuminates when the apparatus is in the
preparatory state. This must contain words that indicate imminent
radiation exposure (e.g. ‘ready’); and
(b) a radiation warning sign which illuminates when the apparatus is in the
loaded state. This must contain words that indicate radiation exposure
(e.g. ‘beam-on’).
Within the radiation source room, radiation warning devices, both visible and
audible, must be activated when the apparatus is in the preparatory state and the
loaded state.
Note: For this test:
(a) The warnings during each of the states must be clearly
distinguishable from each other.
(b) The visible devices must contain words to indicate the state of the
apparatus.
(c) The audible alarm must be a mechanism which allows the person
to detect a change of circumstances audibly.
(d) The radiation warning devices must either:
(i) be fail safe (i.e. beam turns off if a device fails), or
(ii) adequate warning that a device has failed must be indicated,
at the control panel, in a clear and unambiguous manner.

13. Warning lights
At each entrance through which entry to the radiation source room is possible,
an illuminated radiation warning sign must be provided.
This illuminated radiation warning sign must be connected into the X-ray
generator circuit in such a way that:
(a) it illuminates when the X-ray tube is energised and which indicates that the
radiation apparatus is operating; and
(b) it does not illuminate at any other time.
A radiation warning sign combined with a light is also acceptable.
The illuminated warning sign or light must be fail safe (ie. turns the beam off if
the sign or light fails), or adequate warning that a sign or light has failed must
be indicated in a clear and unambiguous manner.
Note: This requirement does not apply to rooms that can only be accessed
from the radiation source room.

14. Worker protection Trapped persons should be able to :
leave enclosure, or
take refuge in shielded area, or
communicate with people outside (alarm)

15. Site Radiography

16. Site Radiography

17. Site Radiography Procedures
1. Prior to work
Prepare the area, consider :
- beam collimation/beam direction
- local shielding/ beam stop
- Calculate distance of barrier
Advise site management

18. Site Radiography Procedures
2. During work
Designated controlled area
- demarcated boundary
- warning notices
- boundary patrolled and monitored
Effective communication between
radiographers in a crew is essential

19. SAFE WORK PRACTICES
The three simple rules to minimize personal radiation doses are:
Time: optimize number of exposures and the exposure time
Distance: keep as far away as practicable from the radiation sources during an exposure (ensuring adequate access control)
Shielding: use collimators or lead sheets (if provided)

20. General safe work practices
Radiation monitoring of the gamma radiography source container - to ensure that the radiation source is in its fully shielded position
Check that delivery tubes, extension tubes and all fittings are in good condition and are not kinked, cracked or broken.
All maintenance work on the equipment, that is not intended by the manufacturer to be undertaken by the user.
Personal alarm dosemeter & personal monitoring device are used at all times during industrial radiography operations

21. Safe work practices
The radioactive substance must be immediately returned to its fully shielded position on the completion of the exposure.
Prior to using the equipment, operators must ensure that:
all interlocks, shielding, collimators, signs, barriers and other safety devices are properly positioned;
all persons not involved in the operation are at safe locations;
suitable radiation monitoring equipment (ie a radiation survey meter) is available and in use.

22. Safe work practices
Equipment which is known to be or suspected of malfunctioning, or is damaged, must not be used.
Industrial radiography must be ceased by returning the radioactive source to its fully shielded position or by de-energising the X-ray tube, as applicable:
 if a malfunction or suspected malfunction of the equipment occurs during operation;
if any person other than the industrial radiographer or assistant industrial radiographer enters a controlled area (where the dose rate exceeds or might exceeds a predetermined dose e.g. 25Sv/h); or
if a radiation survey meter or a personal alarm dosimeter fails to function

23. Safe work practices Enclosed sites/ partially enclosed site
Before commencing an exposure, the industrial radiographer must visually inspect the site to ensure that it is unoccupied.
All entrances to the fully enclosed site must be locked, or interlocked to an audible and visible alarm, during radiographic exposure.
The radiation dose rate must be periodically measured by the industrial radiographer to ensure that it does not exceed the predetermined dose rates in any accessible area outside the partially enclosed or fully enclosed site.

24. Safe work practices Open sites
Erect a well defined and clearly visible boundary (using, for example flagged rope) around the site, including above and below the site as necessary.
The boundary must be located such that the maximum dose rate at the boundary is not exceeded. The boundary must be marked with radiation warning signs.
Radiography equipment and the item to be radiographed must be set up so that each of the components, particularly the X-ray tube or the radioactive substance holder (eg. collimator), are immobilized and therefore will not move during exposure.

25. Safe work practices
Prior to using the equipment, industrial radiographers must ensure that:
all interlocks, shielding, collimators, signs, barriers and other safety devices are properly positioned;
all persons not involved in the operation are at safe locations; and
suitable radiation monitoring equipment (i.e. a radiation survey meter) is available and in use.
Just prior to commencing an exposure, a warning signal must be given to warn persons within a reasonable distance that an exposure is about to take place.

26. Safe work practices During exposures After exposure
The area within the boundary must be kept under surveillance at all times during exposure to ensure that no person enters it or remains within it.
After exposure
Before a site is vacated, the industrial radiographer must ensure, by monitoring, that all radiation sources are locked in the fully shielded condition or switched off, as appropriate, and returned to the store or to the transport vehicle and that all boundary-defining equipment has been removed.

27. Equipment Maintenance
Condition of containers :
clean (no grit/moisture)
shielding intact
warning notices/source details

28. Equipment Maintenance
Condition/operation of wind-out gear:
cable crank
locking key/mechanism
guide tube
connectors

29. Equipment Maintenance
Sources to be leak tested :
indirect wipe of surfaces (guide tube)
direct wipe of source (using specialised equipment)
Carried out at intervals :
required by regulatory body, or
recommended by source manufacturer, or
following an incident

30. Transport of Gamma Radiography Equipment
The source control or shutter mechanism of the source container must be locked in the fully shielded position, and all port plugs must be securely fitted prior to transport.
Before and after transport, radiation monitoring must be carried out to demonstrate that:
the useful beam is properly attenuated with the shutter or source control mechanism in the fully shielded position;
the attenuated radiation exposure pattern is as expected (compare with the measurement in the radiation source movement record book); and
radiation dose rates do not exceed 2000Sv/h at 5cm from the external surface, or 100Sv/h at 1m from its surface.

31. Transport Of Gamma Radiography Equipment
If the gamma-radiography source container is packed in an outer shipping container, the source container must be firmly secured within the outer container.
The gamma-radiography source container is to be located in the vehicle so that the radiation dose received by any person traveling in the vehicle is as low as practicable. The maximum dose rate at the position of any person in the vehicle must not exceed 5Sv/h.

32. Summary Compound Radiography - Design of enclosure
- Effective engineering controls
Site Radiography Procedures
Equipment Maintenance