inspection of personal radiation protective equipment · inspection of personal radiation...
TRANSCRIPT
Inspection of personal radiation
protective equipment
22-9-2017
Ing. W. Stam
Radiation Protection Expert (lvl 3)
Radiontec
Introduction
• Verification of quality/ reliability
– Responsibility for management and
employee
• Rejection criteria?
– No standard
– Differences between institutions and
organisations
Practical issues - 1
• Single- or double layered
apron, skirt, vest
• Thyroid collars, glasses,
gloves.
• Lead equivalence 0,25/
0,35/ 0,50 mmPb (single
layer)
• Labels, sizes, materials
Labelling / personalisation
Practical issues - 2
• Fluoroscopy, moveable table/ support, remote control panel
• Labelling of items (sticker, marker, s/n, inventory number,
personalised)
• Lead ruler or ‘integrated measuring tool/ruler’
• Storage device for documentation, laptop or form for
registration
• Inspection tags
• MAKE SURE NO TLD is left behind on the PrPE
• Recommended;
– 100% coverage rather then random sampling
– Annual check
– Acceptance
Additional dose
a
S
Reference:
Health physics – operational radiation safety:
Inspection of Lead aprons: Criteria for Rejection - Lambert and McKeon 2001
Relation: area a ~ lenght L
• L ~ a
• Assumption
– Crack leads to area of a circle
– Worst case scenario
• 2L = 2r
– L = r
– r = L /
L
r
References:
Health physics – operational radiation safety:
Inspection of Lead aprons: A practical Rejection Model - Pillay and Stam 2008
Model for rejection
• Considers;– Type of PrPE (single or double
layer, thyroid collar)
– Transmission (0,25/0,35/0,50
mmPb)
– Location (wt) • Whole boby: wt = 1
• Thorax: wt = 0,8
– Geometry of exposure
(AP/PA/LAT)• AP (100%) > Cf = 1
• PA (10%) > Cf = 10
• LAT (30%) > Cf = (10/3)
– H = 100 mSv/year (no T) front
References:
Health physics – operational radiation safety:
Inspection of Lead aprons: Criteria for Rejection - Lambert and McKeon 2001
Inspection of Lead aprons: A practical Rejection Model - Pillay and Stam 2008
Rejection criterium
• Now there is a model to calculate the
additional dose (in the worst case)
– The question still is…
• For which additional dose (mSv/year) a
PrPE will be rejected?
– applicable for each type of PrPE, for each
mmPb, geometry, etc.
– Erejection = 0,22 mSv (empirical)
Plot Eadditional ~ L
Registration
Why inspect?
Thank you for your attention!
Any questions?
5th IRPA congress - 2018
References:
Health physics – operational radiation safety:
Inspection of Lead aprons: A practical Rejection Model - Pillay and Stam 2008