8: Safe Working Procedures Flashcards
As per CNSC regulations, what is an exposure device used for?
Carrying out gamma radiography
As per CNSC regulations, what does an exposure device include?
Sealed source assembly, drive cable or drive tube and a source guide tube
Industrial radiography works with what range of radiation intensity (GBq)?
740 GBq - 3700 GBq
As per regulations, what does “operate” entail?
Coupling/uncoupling drive mechanism, locking/unlocking exposure device and ALL activities while source is not locked inside device in fully shielded position.
Work must be stopped immediately if EDO becomes aware of a reading reaching what amount?
2 mSv/h (200 mR/h)
What two types of exposure devices are there?
- Cable operated (cable drive)
2. Pneumatically operated (air drive)
What does a cable operated exposure device contain?
Source attached to pigtail which includes locking ball, Teleflax cable and a connector
How does the source get to the end of the guide tube in a cable operated exposure device?
With a drive cable and crank
How does the source get to the end of the guide tube in a pneumatically operated exposure device?
A pneumatic pump and drive tube
What does the GO NOGO gauge inspect?
Pigtail (female connector)
Which exposure device uses a double acting pump?
Pneumatically operated
What should you inspect the guide tube and drive tube for?
Kinks, cuts or breaks
What should you inspect the connectors for?
Damage, dirt and wear
What should you inspect the nozzle for?
Firmly in place on the guide tube
What does a pipeline exposure device contain?
Boomer plate with chains and spring loaded boomer handle to secure device in multiple positions
Who certifies ALL exposure devices used by CEDO’s in Radiography?
CNSC (Canadian Nuclear Safety Commission)
The final radiograph must contain 3 things…
- identification of item inspected
- location identifiers
- image quality indicators
What is clock tape?
Lead numbers sealed in transparent plastic tape that’s made in house
IQI (Image Quality Indicators) indicate which 2 things…
Quality and sensitivity
IQI’s must be made of what?
Same material as component inspected
What are the two types of IQI’s?
- Plaque/hole type
2 Wire type
How do you know which type of IQI to use?
Specified by codes and standards
A plaque type penetrameter is percentage of the component’s thickness?
2% (thousands of an inch)
You have a 1 inch thick section which is calculated by - 1 x 2% = 0.020”
What number penetrameter would you use?
20
You have material that is 8 inches thick, calculated by - 8 x 2% = 1.6”
What number penetrameter would you use?
16
How do you measure the sensitivity of an inspection?
The smallest visible hole
When using a plaque type penetrameter, where should it be placed in relation to area of concern?
BESIDES area of concern (instead of over it)
Describe a Wire Type IQI…
6-8 wires arranged in order of increasing diameter, between 2 sheets of clear, vinyl plastic
The smallest wire (#1) of the Wire Type IQI is equivalent to what ASTM hole type penetrameter?
7 ASTM hole type penetrameter
The largest wire (#6) of the Wire Type IQ is equivalent to what ASTM hole type penetrameter?
25 ASTM hole type penetrameter
Shooting a circumferential weld can be divided into 2 techniques, what are they?
Single/double wall exposure and single/double wall viewing
Describe single/double wall exposure:
Radiation travels through one or two wall thicknesses
Describe single/double wall viewing:
One or both walls of the tubular section are visible on radiograph
Contact exposure (DWE w/ SWV)
Source against specimen, shielded with collimator, only bottom part of weld visible on radiograph and mainly used on small pipes