AN/VDR-2 RADIAC SET

AN/VDR-2 RADIAC SETHOW TO PMCS AND OPERATERADIOLOGICAL DETECTORENABLING LEARNING OBJECTIVESTANDARDS: Be able to perform a PMCS and operate AN/VDR-2 Radiac Set. Prepare Radiac Set in accordance with TM and stating the contamination reading obtained from an area survey, personnel monitoring, and equipment monitoring. AN/VDR-2 RADIAC SETDESCRIPTION:1. Use to locate and measure gamma and beta particles.2. Lightweight, battery operated, and self testing.3. Measurement is in Gy (unit of Gray)4. cGy - centigray, Gy Gray, and uGy microgray.5. Negligible risk factor is 1 cGy.WARNING!!!!The high range detector contains one (1) nanocurie of Thorium (th) 232, and is controlled by U.S. Army Reg. 385-11.COMPONENTS OF THE AN/VDR-2RADIACMETERPROBEPOUCHSTRAP

CAPABILITIES1. Detects, measures, and displays level of gamma radiation dose rate from .01 uGy/hr to 100 Gy/hr.2. Detects and displays level of beta particles dose-rate from .01 uGy/hr to 5 Gy/hr.3. Measures, stores, and displays accumulated dose (total dose) from .01 uGy to9.99 Gy.4. Flashing display to indicate reduced accuracy condition when measuring dose rate from 10 Gy/hr.

FEATURES1. Liquid Crystal Display (LCD):3 digits decimal pointUnit of measurementIndicates low batteries or fault2. Can be vehicle mounted3. Audible or visual alarm independently preset for dose rate and accumulated dose.

POWER SOURCES1. Main power- 3 ea (9 volt batteries).2. Vehicle power- 24 VDC.3. Main power battery life- 100 hrs.

Will retain memory for 5 min. after batteries are removed.

3- 9 volt batteriesCONTROLS AND INDICATORS

CONTROLS AND INDICATORS CONTINUED

DIGITAL DISPLAY INDICATIORS1. Low battery indicator (flashing/hr).2. Decimal indicators.3. Digits.4. Dose units.PREVENTIVE MAINTENANCERoutine Checks:A. All cables.B. Loose or broken lights or covers.C. Inspect panel.D. Remove all foreign debris.E. Inspect batteries and compartment.PREPARE AN/VDR-2 FOR USE1. The AN/VDR-2 must be turned off when disconnecting/charging probes or batteries.2. Install batteries.3. Install meter in pouch.4. Conduct pre-operational test.PRE-OPERATIONAL TEST PROCEDURES1. Set power to ON.2. Set ALM to AUD.3. Press and hold CLR/TEST button until alarm sounds for 2 seconds, then release.4. When the segment displays, insure it is exactly as shown.

0.00 uGy55.5 cGy11.1 uGy666 cGy222 uGy77.7 Gy.333 cGy888 Gy4.44 cGy999 GyPRE-OP TEST CONTINUED5. Set ALM to off, then VIS. The dose rate lights will come on.6. Once the segment test is complete the unit will automatically go through the unit/digit test and electrical test.7. If all tests are ok, you will see a flashing 9.8. If there is a fault, you will see a flashing 8.9. Once you see the flashing 9, press the CLR/TEST button.10. Tests are complete.

USING AN/VDR-21. Surveying for beta/gamma contamination.A. Stand in an open area, 10 meters from any shielding objects.B. Hold unit waist high.C. Slowly turn in a full circle.D. Record highest reading received.There are 2 types of monitoring procedures.DirectOutside of any shielding objects.IndirectStand in middle of room or area and do testing.Direct Monitoring ProceduresStep 1 (b)

36010 Meters360Direct MonitoringSimplest and most precise type of monitoring.

Consists of unshielded dose rate readings.

Used when conditions and Operational Exposure Guidance (OEG) permit

Indirect Monitoring ProceduresStep 2 (b)360CenterIndirect MonitoringMeasure dose rates within an area shielded from radiation.

Allows the unit to measure radiation levels and still keep exposure to a minimum.

Preferred method when operating in a contaminated area.USING AN/VDR-2 CONTINUED2. Determining Background Radiation.A. Turn or walk away from the suspected contamination.B. Open beta shield.C. Observe reading for 5-10 sec. Record highest reading.D. Multiply by 2.E. If the reading is twice background or higher, contamination is present.F. Report the results.

USING AN/VDR-2 CONTINUED4. Monitoring personnel.A. Take background.B. Have the person being monitored stand with feet apart, and arms extended with palms upward.C. Hold probe 1 inch from personnel.D.. Pass over entire body, starting with the head.E. Any reading above the background is contaminated.IDENTIFYING TYPES OF RADIATION USING THE AN/VDR-2Contamination: Before something can be considered contaminated, a reading 2 times higher than the background must be obtained.NO CONTAMINATION PRESENTYour background reading is 2 uGy/hr; multiply by 2 which gives you 4uGy/hr. Your open shield reading is 3 uGy/hr and the closed shield reading is 3 uGy/hr . Both readings were not twice the background, therefore. No contamination is present.IDENTIFYING TYPES OF RADIATIONBeta Only-Your background reading is .2 uGy/hr times 2 is .4 uGy/hr. Your open shield reading is 2.5 uGy/hr which is more than twice the background reading. The closed shield reading is .2 uGy/hr. It is not twice the background, therefore, you have beta only.

Both Beta & Gamma Contamination-Your background reading is .2 uGy/hr times 2 is .4 uGy/hr. Your open shield reading is 3.4 uGy/hr which is more than twice the background reading. The closed shield reading is 2.2 uGy/hr. It is also twice the background. Therefore, you have both beta and gamma radiation present.

QUESTIONS??