Environmental Monitoring Procedure Using the Radiation Alert® Area Monitor
The Radiation Alert® Area Monitor serves a different purpose than handheld survey meters such as the Ranger or GammaView. Rather than performing periodic surveys, an Area Monitor is designed for continuous, unattended radiation surveillance with alarm notification, data logging, network connectivity, and remote monitoring capabilities. It can be configured with either energy-compensated GM detectors or NaI scintillation detectors depending on the environmental monitoring objectives.
Purpose
Environmental monitoring with an Area Monitor is intended to:
- Continuously monitor ambient radiation levels.
- Establish long-term environmental radiation trends.
- Detect abnormal radiation increases.
- Monitor site boundaries.
- Provide early warning of releases or source movement.
- Support NRC, Agreement State, DOE, industrial, or facility-specific monitoring requirements.
Ideal Environmental Applications
Facility Perimeter Monitoring
Install monitors at:
- North boundary
- South boundary
- East boundary
- West boundary
The monitor continuously measures dose rate and provides alarms if preset thresholds are exceeded. Email and text notifications can be configured for immediate response.
Waste Storage Areas
Monitor:
- Radioactive waste accumulation areas
- Source storage vaults
- Decay storage rooms
The system can generate alarms when radiation levels rise unexpectedly.
Environmental Surveillance Stations
Permanent environmental stations can be established near:
- Public access points
- Surface water discharge areas
- Stormwater retention ponds
- Groundwater monitoring wells
- Security fence lines
Continuous measurements provide much more useful trend information than periodic surveys alone.
Detector Selection
NaI Scintillation Area Monitor (AM-1X1)
Recommended for:
- Environmental background monitoring
- Low-level gamma detection
- Perimeter monitoring
- Off-site NaI environmental monitoring
NaI detectors provide excellent sensitivity to small changes in gamma background levels.
Energy-Compensated GM Area Monitor
Recommended for:
- General area dose-rate monitoring
- Higher-radiation environments
- Emergency response monitoring
These models offer wide measurement ranges and are useful where elevated dose rates may occur.
Continuous Data Collection
One of the strongest features of the Area Monitor is continuous logging.
Measurements may include:
- µR/hr
- mR/hr
- µSv/hr
- CPM
- CPS
depending on detector type and configuration.
Trend data can be archived and reviewed as needed.
Environmental Event Monitoring
Rain Events
After heavy rainfall, natural background may temporarily increase due to atmospheric radon daughters washing out of the atmosphere.
Continuous monitoring helps distinguish:
- Normal environmental fluctuations
- Actual contamination events
Severe Weather
Monitoring provides valuable information following:
- Hurricanes
- Floods
- Tornados
- Wildfires
to determine whether radioactive materials have migrated or become exposed.
Investigation of Elevated Readings
When the Area Monitor alarms:
- Verify detector status.
- Check for maintenance-related activities.
- Review recent weather conditions.
- Perform a handheld survey using:
- Ranger
- GammaView
- Other calibrated survey instruments
- Determine whether the increase is localized or widespread.
- Document findings.
Example Environmental Monitoring Network
Potential Radioactive Materials Facility Configuration
| Location | Instrument |
| North Boundary | Area Monitor 2×2 NaI |
| South Boundary | Area Monitor 2×2 NaI |
| East Boundary | Area Monitor 2×2 NaI |
| West Boundary | Area Monitor 2×2 NaI |
| Waste Storage Area | GM Area Monitor |
| Source Storage Room | GM Area Monitor |
| Public Entrance |
All units would report to a central computer using the included monitoring software for real-time review and alarm notification.
Best Practice
For a comprehensive environmental radiological surveillance program:
- Use the Area Monitor for continuous monitoring and alarming.
- Use the GammaView for periodic environmental investigations and high-sensitivity surveys.
- Use the Ranger for contamination surveys and wipe testing.
Together, these three instruments provide continuous surveillance, environmental trending, investigation capability, and contamination assessment, creating a robust environmental monitoring program suitable for most NRC-licensed or Agreement State facilities.