6. SOP-1: Vehicle Stop / Traffic Incident

6.1 Scenario

A patrol officer is on a routine traffic stop, a checkpoint, or has rolled up on a single-vehicle accident. Their belt-worn PRD alarms. The officer is now standing close to a possibly radioactive source, may not know what cargo the vehicle is carrying, may not have ID on the driver, and may have civilians on the shoulder.

6.2 Objectives

1. Keep the alerting officer safe.
2. Keep public traffic moving safely around the scene.
3. Confirm or refute the alarm with a survey meter.
4. Identify the source with a SAM family handheld RIID.
5. Determine whether this is a routine event (NORM, medical, licensed cargo) or a true threat.
6. Hand the event off to the right downstream resource (state RCP, federal partner, transport authority) with a clean reachback packet.

6.3 Triggers for SOP-1

• Patrol PRD alarm
• Vehicle accident with placarded radioactive cargo
• Officer-in-distress call referencing radiation
• Citizen report of a vehicle "with a radiation symbol on it"
• Border or weigh-station portal alarm

6.4 Actions (Ordered)

Phase 1, Immediate (first 5 minutes, alerting officer):

1. Step back to the patrol vehicle. Doors closed.
2. Note PRD reading (count rate, dose rate if shown), time, location.
3. Radio dispatch: "Possible radiological alarm, request HazMat with RIID, holding position."
4. Do not allow the driver to leave the vehicle if they can be safely instructed to stay. Do not place yourself between the vehicle and traffic.
5. If a citizen is at higher risk (e.g., bystander between the vehicle and the cordon), instruct them to step back behind the patrol vehicle.

Phase 2, HazMat arrival (5–15 minutes):

6. Approach the scene from upwind, behind the patrol vehicle.
7. Confirm with the patrol officer: time of alarm, peak reading, vehicle description, driver status, any visible labels or placards.
8. Sweep with a survey meter from the patrol vehicle outward. Note the dose rate at multiple distances. Verify the inverse-square pattern (a real point source falls off; a spread-out NORM cargo falls off more gently).
9. Establish a working perimeter where dose rate equals 2× background or below.

Phase 3, Identification (15–30 minutes):

10. Power on the SAM family handheld. Self-test, calibration check, GPS lock.
11. Acquire background at the working perimeter. Save it.
12. Approach the vehicle along the safest line, typically the driver's side, behind the patrol vehicle's protection if possible.

BNC in Practice: The Driver's-Side Approach

Cargo sources sit in the trailer or rear box, not the cab. Approaching from the driver's side keeps the patrol vehicle between you and the cargo line, and lets you see the driver's hands during the scan. Place the SAM unit against the door at sill height, low enough to read the cargo, high enough to avoid wheel-arch shielding. Hold the geometry; do not wave the unit.

13. Place the SAM unit at a position where count rate is above background but personal dose rate is acceptable. Common positions: against the driver's-side door, on the hood, against the side panel near the cargo.
14. Allow the scan to run. Watch confidence build.
15. Save the spectrum. Photograph the vehicle, license plate, any placards, any visible cargo.

Phase 4, Send and Decide (30–60 minutes):

16. Transmit reachback packet (see §6.6).
17. Brief the IC with a plain-language summary: "Cs-137, high confidence, source appears to be in trailer, dose rate at perimeter is 0.05 mR/hr."
18. Hold the cordon. Do not let the vehicle leave until command authorizes.
19. Coordinate with state radiation control program (RCP) and, if the source is licensed industrial, with the licensee. Many "alarms" turn out to be lawfully transported industrial gauges.
20. If the source is unlicensed, unexpected, or inconsistent with the vehicle's manifest, escalate per agency protocol.

6.5 Decision Points

Reading	Identification	Likely Action
Slightly elevated, < 2× background	NORM consistent with cargo (granite, tile, fertilizer)	Document, release with note
Moderate, identified medical	Patient discharge with Tc-99m, F-18, I-131	Verify driver/patient, document, release
Moderate, identified industrial (Cs-137, Co-60, Ir-192, Am-241)	With manifest match	Hold pending licensee/RCP confirmation
Moderate, identified industrial	Without manifest match	Hold; treat as potentially diverted; reachback
High, identified or unidentified	Any	Cordon, escalate, request federal/state assistance
Any reading + neutron alarm	Possible SNM	Cordon, escalate immediately

6.6 Reachback Packet for SOP-1

Send to your reachback channel (BNC reachback or your agency RCP channel, whichever your SOP designates):

• Spectrum file from SAM unit
• Background spectrum (if separate)
• Photograph(s) of vehicle, plates, placards, manifest if available
• GPS coordinates and time
• Officer narrative (driver demeanor, cargo type if known, anything anomalous)
• Dose rate readings at three distances
• Operator name, agency, callback number

6.7 Common Pitfalls

• Letting the driver step out and stand at the rear of the vehicle. Now they're standing next to (or downwind of) the source.
• Approaching from the wrong side. The source is rarely in the driver's seat; it's almost always in the cargo area. Stand off the cargo line.
• Believing the placard. Placards lie or get rotated. Verify with the instrument.
• Using the patrol vehicle as a shield against high-energy gammas. It helps for low energies; it's nearly transparent to Co-60 or Cs-137 (HVL exceeds vehicle door thickness). Use distance, not steel.
• Calling the press too early. Most vehicle stops are NORM or licensed cargo. A wrong public statement is harder to clean up than a true positive.

6.8 SOP-1 Checklist (Tear-Out)

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