GKN Aerospace — Hazard Zone Simulator

GKN AEROSPACE — HAZARD ZONE SIMULATOR

⚠ What happens if it fails?<br>📡 Live social<br>12122 WESTERN AVE, GARDEN GROVE CA | MMA TANK EMERGENCY | MAY 23 2026

DATA

&larr; Back to the simulator<br>What happens if the tank fails

&times;

The explosion radius, up close

What to expect at each distance from the tank. These rings track the current scenario in the simulator, so they grow and shrink as you change the leak rate, cascade tanks, and yield.

Fireball · —Total destruction. Nothing inside survives.

Severe (~10 psi) · —Reinforced buildings collapse; near-total fatalities.

Moderate (~3 psi) · —Homes heavily damaged or partly collapse; widespread serious injuries.

Glass break (~1 psi) · —Windows shatter for blocks. Flying glass is the main injury, even far from the tank.

The mechanism most coverage misses

MMA (methyl methacrylate) is a monomer : a liquid that wants to link up into plastic. It is kept stable by a small amount of inhibitor. If the tank loses that inhibitor or heats up, the MMA begins to polymerize , turning into solid acrylic, the same material as Plexiglas. That reaction gives off heat, and the heat makes it run faster, so it can accelerate on its own. A tank that stays in crisis for days is a slow polymerization runaway that crews are working to keep cool.

It is a race between two endings

Controlled: the heat escapes fast enough and the contents harden into a block of solid plastic. The tank is destroyed, but there is no explosion. Keeping it cool is what produces this outcome.

Runaway: heat builds faster than it can escape. The remaining liquid boils (MMA boils near 100&deg;C / 212&deg;F) and flashes to vapor, pressure climbs, and the tank ruptures. At very high temperature the new plastic can break back down into vapor, adding still more pressure.

So it solidifies and pressurizes at the same time. Which one finishes first decides whether you get a ruined tank or an explosion.

Three ways a failure can go

BLEVE (boiling-liquid expanding-vapor explosion): the tank bursts while its contents are superheated. Fireball, pressure blast, and tank fragments thrown far.

Vapor-cloud explosion: vapor that has pooled along the ground drifts out, finds an ignition source, and ignites all at once. This is what the simulator's blast rings estimate.

Pool fire: the spilled liquid simply burns, feeding the toxic plume.

Why the zones look the way they do

The blast rings run from the fireball out to a glass-break radius. That outer ring matters most for injuries: windows shatter blocks away and flying glass hurts people who felt safe. The toxic plume is separate. MMA vapor is heavier than air, so it hugs the ground and drifts downwind, irritating eyes and lungs. The evacuation area is sized for the glass-break radius plus the downwind plume, which is why the wind direction changes the picture so much.

Incident

ChemicalMMA C₅H₈O₂

Volume7,000 gal

TNT equiv.—

Flash pt.2°C / 36°F

Vapor density>1 (sinks)

IDLH1,000 ppm

Wind (Live-driven)

FromWest 270°

Speed8 mph

Gustsup to 20 mph

Fallout toNE

Observed Weather (Live)

Conditionsloading…

Temp—

Humidity—

Wind—

Gusts—

Updated—

Source—

Air Quality (Live)

US AQI (site)—

Categoryloading…

PM2.5—

Updated—

Tracks smoke & particulates (PM2.5), not MMA vapor directly. Source: Open-Meteo (keyless).

Layers

Base map

Blast zones

Toxic plume

Evac order

Shelters

Reference evacuation-site locations — call to confirm space & pets, and follow official orders.

Air quality sensors

Live PurpleAir sensors, colored by AQI. Smoke/particulates, not MMA vapor.

Scenario

VCE efficiency 10%

Wind speed (mph) 8

Volume (gal) 7,000

Leak rate (kg/s) 40

Per-tank evaporation/venting rate that feeds the plume. Realistic MMA pool ≈ 2–8 kg/s.<br>The dominant lever on plume reach. Each cascade tank below adds another source this size.

Plume dispersion model

Dense-gas (B-M)<br>DEGADIS<br>(two-phase)

Britter-McQuaid — screening dense-gas model. Heavier-than-air vapour slumps and hugs the ground, reaching farther than a neutral plume. The default for MMA. ±factor 2-3.

Cascade Failure

Officials say the tank sits beside 2 other storage tanks . A blast can trigger<br>sympathetic detonation. Toggle the neighbours (worst case: 34,000 gal each, full).<br>Cascade grows the blast (combined fuel) and the plume — each failing<br>tank adds another leak of the rate set above.

Tank 2 (+34,000 gal)

Tank 3 (+34,000 gal)

Total volume7,000 gal

ScenarioSingle tank

Blast scale—

Plume source4 kg/s

TNT-equivalent = blast energy only (not radiation/fallout).

Blast legend

Fireball / total destruction

Severe structural damage

Moderate damage / injury

Glass break / eardrum

Plume legend (Britter-McQuaid dense-gas)

IDLH >1,000 ppm — lethal

ERPG-2 75 ppm — serious

ERPG-1 10 ppm — irritation

Distances

Fireball—

Severe—

Moderate—

Glass break—

IDLH plume—

ERPG-2—

ERPG-1—

Model Comparison

Four models, each deriving the hazard from first...