Electronic Dosimeter Canberra Mini-Radiac Electronic Personal Dosimeters (EDs) are commonly used in the industry and now by first responders as real-time, easy-to-read dosimeters. They are generally composed of either semiconductors or Geiger tubes and most have alarming features.

ED Advantages Advantages Alarms alert user Can be read by user at scene Can be set to alarm on dose or dose rate Can measure both dose and dose rate Gamma and x-ray doses (some available for beta and neutron) Able to measure a wide range of doses

ED Disadvantages Disadvantages Not as accurate as TLDs Most have to be programmed More expensive than TLDs or DRDs Require batteries Some are not rugged (but some are) ED = Electronic Dosimeter DRD = Direct Read Dosimeter TLD = Thermo Luminescent Dosimeter

High Dose Rates For emergency life rescue operations, without a high rate survey meter, you can use an electronic dosimeter as a substitute if the dosimeter can read high rates (200 R/hr or higher) Do not hold your dosimeter up to sources because that can make your dose reading higher than what your body actually received

Canberra Mini-Radiac Dosimeter Max Rate: 500 R/hr Max Dose: 999 R Rugged & Water Resistant Large Display & Large Buttons Designed to be operated while wearing gloves and PPE Two Levels each for Dose & Rate Alarms Low: Caution, Near Radioactive Material High: Danger, Snatch & Grab Rescue

Canberra Mini-Radiac Units Dose Button Rate Button On/Off Button The ED that CTOS uses for training is the Canberra Mini-Radiac. We will go over all the features of the ED slowly so that you can follow along with the slide. Instructions: Press ‘Enter’ – the on/off button is highlighted. Tell them that they have to hold the button until 000 is displayed. Press ‘Enter’ – the rate button is highlighted. Tell them that they enter the system in the rate mode (uR/hr). Press ‘Enter’ and tell the students to press the dose button – the dose button is highlighted. Tell them that they can switch back and forth between dose and dose rate simply by pushing either button (the word ‘RATE’ or ‘DOSE’ will be displayed at the top). However, the default position is dose rate, so the unit will return to the rate setting after 10 seconds. Tell the students that they can clear the total dose by pressing the ‘DOSE’ and ‘CLR/TEST’ buttons simultaneously and holding them for 3-4 seconds. Press ‘Enter’ – the units are highlighted. Tell the students that whichever mode (dose or dose rate) they are in, the correct units will be shown.

Mini-Radiac: AAA Batteries

4 Types of Mini-Radiac Alarms Low Dose Rate = 1 mR/hr Near something radioactive CAUTION High Dose Rate = 100 R/hr DANGER Turn Back Snatch & Grab Rescue GREEN The four alarms are pre-set values. They are (dose rate): L=100 uR/hr (training hot line) H=1000 uR/hr (1 mR/hr) (training turn-around for non-life-saving) And (dose): L=100 mR???? H=10 R???? RED

4 Types of Mini-Radiac Alarms (continued) Low Dose = 1 R Approaching EPA 5-Rem Limit for Emergency Activities High Dose = 20 R Approaching EPA 25-Rem Limit for Life-Saving GREEN The four alarms are pre-set values. They are (dose rate): L=100 uR/hr (training hot line) H=1000 uR/hr (1 mR/hr) (training turn-around for non-life-saving) And (dose): L=100 mR???? H=10 R???? RED

Low Dose Rate Alarm Alarm Indicators Visible Dose Rate Alarm (Green) Because we have pre-set the alarms, we are not going to show you how to change the alarm values. What you do need to know is how to acknowledge an alarm. Instructions: Press ‘Enter’ – the alarm indicators are highlighted. Tell them that they will be able to see which alarms are enabled. Tell them that the vibrate alarm is the default setting so that they cannot completely disable any alarm. Press ‘Enter’ – the visible dose rate alarm button is highlighted. Press ‘Enter’ – a low dose rate alarm will be demonstrated. Tell them that if they have enabled the visual alarm, a green light will flash slowly and the words ‘ALARM’ and ‘RATE’ will flash in the display.

High Dose Rate Alarm Visible Dose Rate Alarm (Red) Instructions: (The visible dose rate alarm button is highlighted as before, but the color red indicates a high alarm). Press ‘Enter’ – a high dose rate alarm will be demonstrated. Tell them that if they have enabled the visual alarm, a red light will flash quickly and the majority of the screen will flash.

Low Dose Alarm Visible Dose Alarm (Green) Instructions: (The visible dose alarm button is highlighted, and here the color green indicates a low alarm). Press ‘Enter’ – a low dose alarm will be demonstrated. Tell them that if they have enabled the visual alarm, a green light will flash slowly and the word ‘ALARM’ on the screen will flash.

High Dose Alarm Visible Dose Alarm (Red) DOSE Instructions: (The visible dose alarm button is highlighted as before, but the color red indicates a high alarm). Press ‘Enter’ – a high dose alarm will be demonstrated. Tell them that if they have enabled the visual alarm, a red light will flash quickly and the words ‘ALARM’ and ‘DOSE’ on the screen will flash.

Signals Display (LCD) Vibrate Audio Signal Now that you know about the alarms, we will quickly go over the three signals that make up the alarms. Instructions: Press ‘Enter’ – the LCD is highlighted. Press ‘Enter’ – the audio signal is highlighted. Press ‘Enter’ – the entire ED is highlighted and it vibrates. Press ‘Enter’ – the CLR/TEST button is highlighted. Press ‘Enter’ – this signifies a low alarm condition. Tell them that if they press the CLEAR/TEST button during a low alarm, the Display remains and the Vibrate and Audio signals are de-activated. Press ‘Enter’ – this signifies a high alarm condition. Tell them that if they press the CLEAR/TEST button during any high alarm, the Display and Audio signal remain while the Vibrate signal is de-activated. Press ‘Enter’ and tell the students to press the dose button – the dose button is highlighted. Tell them that they can switch back and forth between dose and dose rate simply by pushing either button (the word ‘RATE’ or ‘DOSE’ will be displayed at the top). However, the default position is dose rate, so the unit will return to the rate setting after 10 seconds. Tell the students that they can clear the total dose by pressing the ‘DOSE’ and ‘CLR/TEST’ buttons simultaneously and holding them for 3-4 seconds Audio Signal

Clearing Low Alarms Display (LCD) Press Clear/Test Button Clear Doesn’t Stop: Display Stops: X Audio X Vibrate Display (LCD) Now that you know about the alarms, we will quickly go over the three signals that make up the alarms. Instructions: Press ‘Enter’ – the LCD is highlighted. Press ‘Enter’ – the audio signal is highlighted. Press ‘Enter’ – the entire ED is highlighted and it vibrates. Press ‘Enter’ – the CLR/TEST button is highlighted. Press ‘Enter’ – this signifies a low alarm condition. Tell them that if they press the CLEAR/TEST button during a low alarm, the Display remains and the Vibrate and Audio signals are de-activated. Press ‘Enter’ – this signifies a high alarm condition. Tell them that if they press the CLEAR/TEST button during any high alarm, the Display and Audio signal remain while the Vibrate signal is de-activated. Press ‘Enter’ and tell the students to press the dose button – the dose button is highlighted. Tell them that they can switch back and forth between dose and dose rate simply by pushing either button (the word ‘RATE’ or ‘DOSE’ will be displayed at the top). However, the default position is dose rate, so the unit will return to the rate setting after 10 seconds. Tell the students that they can clear the total dose by pressing the ‘DOSE’ and ‘CLR/TEST’ buttons simultaneously and holding them for 3-4 seconds Press Clear/Test Button

Clearing High Alarms Display (LCD) Audio Signal Press Clear/Test Doesn’t Stop: Display Audio Stops: X Vibrate Display (LCD) Now that you know about the alarms, we will quickly go over the three signals that make up the alarms. Instructions: Press ‘Enter’ – the LCD is highlighted. Press ‘Enter’ – the audio signal is highlighted. Press ‘Enter’ – the entire ED is highlighted and it vibrates. Press ‘Enter’ – the CLR/TEST button is highlighted. Press ‘Enter’ – this signifies a low alarm condition. Tell them that if they press the CLEAR/TEST button during a low alarm, the Display remains and the Vibrate and Audio signals are de-activated. Press ‘Enter’ – this signifies a high alarm condition. Tell them that if they press the CLEAR/TEST button during any high alarm, the Display and Audio signal remain while the Vibrate signal is de-activated. Press ‘Enter’ and tell the students to press the dose button – the dose button is highlighted. Tell them that they can switch back and forth between dose and dose rate simply by pushing either button (the word ‘RATE’ or ‘DOSE’ will be displayed at the top). However, the default position is dose rate, so the unit will return to the rate setting after 10 seconds. Tell the students that they can clear the total dose by pressing the ‘DOSE’ and ‘CLR/TEST’ buttons simultaneously and holding them for 3-4 seconds Audio Signal Press Clear/Test Button

Light Button Light Button Finally, the display can be lit in dark conditions simply by pushing the ‘LIGHT’ button. If a blinking ‘b’ is displayed on the LCD, the batteries are dead and must be changed before the dosimeter can be used. if a blinking ‘BAT’ is displayed, the dosimeter has less than 10 hours of life left and the batteries must be replaced as soon as possible.

Normal Background on Dosimeter 5 – 30 µR/hr for Dose Rate 5 – 30 µR of Dose for every hour since dosimeter was cleared About 0.25 – 0.5 mR (250 – 500 µR) of Dose per day if dosimeter is left on Finally, the display can be lit in dark conditions simply by pushing the ‘LIGHT’ button. If a blinking ‘b’ is displayed on the LCD, the batteries are dead and must be changed before the dosimeter can be used. if a blinking ‘BAT’ is displayed, the dosimeter has less than 10 hours of life left and the batteries must be replaced as soon as possible.

Training Value Correlation Real World Values Actions Low Dose Alarm 1 R Serious radiological event Administrative controls Rotate teams to stay under 5 R High Dose Alarm 20 R Limit for life saving activities Leave immediately Another team takes over OR volunteer/aware risks/ w/permission Low Dose Rate Alarm 1 mR/hr Three times background Proceed with caution Continue to measure dose rate High Dose Rate Alarm 100 R/hr Time to get out Rapid Egress

Wearing Dosimeters If available, every responder at radiological/nuclear incident should be issued a dosimeter Wear dosimeter between the neck and waist As I said earlier, dosimeters measure the total dose your body has received.

TLD and Another Dosimeter Direct Reading Dosimeter Note this person is using two dosimeters, a TLD and an DRD. The TLD provides an accurate dose reading. The DRD allows the individual to check his current dose while he is in the radiation area, or when he leaves the radiation area. The TLD Dosimeter is more accurate, but must be sent to a lab for processing to get a dose reading. The responder in the field cannot “read” a TLD to see what the dose is. If you only have one type of dosimeter, use what you have. Medical professionals can also determine from blood tests the dose a responder received, if the dose is greater than about 50 rem. TLD Dosimeter