Response Checks of Portable Radiation Detection Instruments

Enabling Objectives Name Instrument Control Procedure State Calibration Organization State Frequency of Response Checks Identify Response Check Equipment Identify Shepherd Components

Enabling Objectives State Isotopes & Activity for Shepherd Sources Identify Response Window Criteria Identify Instruments Response Checked with Plutonium State Purpose of Scintrex Model 309A

Instrumentation Controls “Radiological Instrument/ Equipment Controls”

Instrument Calibration Portable Radiation Detection Instruments Calibrated by: Environmental Radiological Monitoring & Instrumentation (ERM&I) Western Area Radiological Laboratory, (WARL) Muscle Shoals, AL

Response Check Frequency Teletector & RSO-7 Daily Beta-Gamma Instruments Weekly Alpha & Beta Friskers Weekly Neutron Dose Instruments Weekly On-Site REP Instruments Weekly Electronic Dosimeters Quarterly

Response Checks of Beta-Gamma Dose Instruments Shepherd Model 89 Irradiator - Source Rod Assembly - Shielded Calibration Range Assembly - Attenuator Assembly - Table Assembly

Shepherd Source Rod Assembly Cs-137 130 mCi 400 Ci

Shepherd Shielded Calibration Range Assembly

Shepherd Attenuator Assembly

Shepherd Table Assembly

Shepherd Precautions Plugs in Unused Access Ports Hands & Fingers Clear of Door Never Lubricate Source Rod Don’t Twist Attenuator Handles Move Table Slowly Utilize Survey Meter

Shepherd Performance Checks Test the Interlock System - Attempt to Raise Source or Open Door with Power Off - Attempt to Raise Source with Door Open - Attempt to Open Door with Source Raised

Establishing Response Windows Expose at Least Four Instruments Exposure Values Near Midscale Set Window for Each Scale

Response Window Criteria Arithmetic Mean of all Instruments Calculate Highest Percent Difference Calculate Lowest Percent Difference Discard Highest or Lowest Percent Difference if Exceed 10 Percent Response Window = Mean ± 20 % Expressed as Range

Instrument Pre-Operational Checks Inspect for Damage Inspect Switches, Alarms, Controls Inspect Cables & Power Cords Check Battery Strength Instrument in Calibration

Performing Response Checks with Shepherd Irradiator Position Instrument on Guide - Beta Gamma Survey Meter - Teletector - Electronic Dosimeter

Beta-Gamma Survey Meter

Teletector

Electronic Dosimeter

Performing Response Checks with Shepherd Irradiator Position Attenuators and Platform Close Door Raise Source to make Exposure Lower Source to “Off” Repeat for Each Scale Document Results

Observation Window

Response Check of Alpha Survey Instruments Alpha Sources, ie Pu-239 Inspect Mylar Windows Perform Light Test Expose Detector Compare Results with Response Log Check Each Scale or Decade Document Results

Alpha Survey Instrument

Neutron Survey Instrument

Response Check of Neutron Instruments Set up the Instrument Scale Instrument Over Neutron Source Check Other Scales/Decades with Pulse Generator Compare Results with Response Log Document Results

Frisker

Response Check of Friskers Sources Identified in Response Log Set Frisker to Appropriate Range/Scale Position Probe over Source Repeat for Other Scales Compare Results with Response Log Document Results

Tritium in Air Monitor

Response Check of Scintrex Model 309A Inspect Filter Paper Ensure Battery >3.0 volts Set Function Switch to ‘Display On’ Press ‘Test’ Button Observe Display < 50

Response Check of Scintrex Model 309A Position Gamma Source on Right Side Wait 1-2 Minutes Observe Reading Between 8 & 24 Depress ‘Test’ Button Document Results

Summary Instrument Calibration Critical Response Checks Confirm Operation Shepherd Model 89 Irradiator Other Response Checks: - Alpha Survey Instruments - Neutron Instruments - Friskers - Tritium-in-Air

Prevent Errors - Reduce Contamination