Inspection of personal radiation protective equipment · Inspection of personal radiation protective equipment 22-9-2017 ... laptop or form for ... Inspection of Lead aprons: ...

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