7. SOP-2: Public Event & Wide-Area Search

7.1 Scenario

A public event, a parade, a stadium game, a political rally, a marathon, a national holiday celebration, needs a pre-event sweep and active monitoring during the event. Or, separately, a known orphan source has gone missing and a wide-area search is required to find it.

7.2 Objectives

1. Confirm the venue is clear before the event begins.
2. Maintain detection coverage during the event without creating bottlenecks.
3. Locate any anomalous reading quickly and identify its source.
4. Distinguish background heterogeneity (granite buildings, tile, fertilized turf) from genuine sources.
5. Hand off identifications cleanly to incident command and reachback.

7.3 Triggers for SOP-2

• Pre-event sweep tasking
• Active venue monitoring
• Wide-area search for a lost or stolen source
• Federal protective detail support
• Post-incident search after a credible threat

7.4 Actions (Ordered)

Phase 1, Mission planning:

1. Define search area and divide into sectors. A grid pattern works for open ground; venue floor plans work for buildings.
2. Assign a backpack operator + handheld operator to each sector. The backpack searches; the handheld confirms.
3. Pre-stage RD-150 vehicle units along high-traffic routes (entry corridors, parking access, perimeter loops).
4. Confirm reachback channel is up. Confirm radio comms across the team.

Phase 2, Pre-event sweep:

5. Each backpack operator walks their sector at a steady pace.
6. The tablet shows live count rate, alarm status, and GPS track.
7. When an alarm fires, the operator stops, marks the location, and signals the handheld operator.
8. The handheld operator follows §5 (Operations Core) to identify.
9. Identifications are categorized: NORM (release), medical (note and release), industrial (verify against site survey), threat candidate (escalate).

Phase 3, Active event monitoring:

10. Backpack and vehicle units continue routes through the event period.
11. Fixed-station portal monitors (if deployed) feed the same operations center.
12. Any new alarm triggers the same handheld follow-up.
13. Operations center maintains a real-time map of all alarms and resolutions.

Phase 4, Wide-area search (if applicable):

14. Establish a search grid centered on last-known location, with grid spacing matched to the source's estimated activity.
15. Backpack operators walk the grid at steady pace; vehicle units cover roads and parking.
16. Aerial and rotorcraft assets, if available, run higher above ground at reduced sensitivity but huge coverage.
17. Concentrate on high-probability areas: places where a person could leave or hide a small object, dumpsters, parking structures, secluded corners.
18. When a hotspot is found, follow §5 with the handheld.

7.5 Decision Points

Situation	Likely Action
Building made of granite/concrete shows elevated background	Treat as NORM venue; raise alarm threshold
Patient with recent Tc-99m enters venue	ID, log, allow entry per SOP, alert next sector
Anomalous alarm in a low-NORM area	Investigate fully with handheld
Confirmed Cs-137/Co-60/Ir-192 in a public area	Cordon, evacuate as appropriate, federal/state escalation
Neutron alarm	Treat as SNM until proven otherwise; escalate
Wide-area search yields a backpack hotspot	Mark GPS, photograph, follow up with handheld; do not move the source

7.6 Reachback Packet for SOP-2

Same content as §6.6, plus: - Sector map with operator track from the RD-120 backpack - Time-tagged sequence of alarms and resolutions - Operations center summary (handed off to reachback shift physicist)

7.7 Common Pitfalls

• Walking too fast. The backpack is calibrated for normal walking pace. A jog kills sensitivity.
• Ignoring repeated low-level alarms in NORM environments. Set the threshold appropriately for the venue's NORM signature.
• Single-operator sectors. If the backpack operator finds something, they need to keep searching while a second operator confirms with the handheld. One person cannot do both efficiently.
• Unclear alarm escalation rules. Every alarm needs a defined path: who decides, what they decide between, by when.
• Battery management. A backpack run all morning needs a battery swap before the afternoon. Plan rotation explicitly.

7.8 SOP-2 Checklist (Tear-Out)

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