RT Radiation Safety

Question 1

What are the hierarchy of control measures?

Answer 1

Eliminate -> substitute -> Engineering controls -> Systems of work -> PPE

Question 2

What engineering controls are there in RT?

Answer 2

Wall shielding (primary and secondary).

Entrance (maze or door).

Interlocks, light curtain, emergency off, last man out, MU chambers (dose/flat and sym).

Question 3

How is designation used to protect staff?

Answer 3

Controlled area used when WB dose likely to exceed 6 mSv, require local rules.

Supervised area when WB dose likely to exceed 1 mSv. Area should be kept under review and LR are optional.

Question 4

Name warning devices in RT areas?

Answer 4

Lights, signage, audible and radiation monitors.

Question 5

In terms of radiation protection, what is different between a linac bunker and a HDR room?

Answer 5

Linac has primary and secondary shielding, whereas HDR is all primary.

Linac has thicker shielding due to higher E beam.

Instantaneous dose rate monitors for HDR rooms due to nature of source, not required in linac bunker.

Linac has more access controls due to higher dose rate nature.

Question 6

What are the roles of PPE in a HDR room versus a linac bunker?

Answer 6

For HDR we have lead aprons and an instantaneous dose rate meter. For linac there are TLDs for WB monitoring and environmental monitoring.