Nuclear Impact Analysis · Brazil

Is Rio de Janeiro safe from a nuclear strike?

We modelled the most plausible strategic targets around Rio de Janeiro and simulated blast, thermal, radiation and fallout effects against its 13,600,000 metro residents.

100/100
MINIMAL RISK

Rio de Janeiro city centre sits 363.2 km from São Paulo (Paulista), the most plausible strategic target in the area (low targeting confidence). Modelled strike: 300 kt airburst.

Estimated survival chance at city centre: 99% · Estimated metro fatalities: 855.9K, injuries: 1M

Run the interactive simulation for Rio de Janeiro →

What a strike on São Paulo (Paulista) would mean

A 300 kt detonation produces a fireball 646 m across in radius. Reinforced concrete fails out to 2.3 km (20 psi). Most residential buildings collapse within 4.6 km (5 psi), and windows shatter dangerously out to 10.4 km (1 psi). Anyone in line of sight within 6.9 km suffers third-degree burns from the thermal pulse.

An airburst maximises blast damage but produces minimal local fallout, so for Rio de Janeiro the dominant risks are blast and thermal effects rather than radiation.

Most plausible targets near Rio de Janeiro

TargetTypeDistanceAssumed yieldConfidence
São Paulo (Paulista)city363 km300 ktlow
Buenos Airescity1968 km150 ktlow
Lagoscity6025 km100 ktlow
Johannesburgcity7120 km100 ktlow
Kings Bay Naval Base (SSBN)military7240 km800 kthigh

Key blast radii (300 kt airburst)

EffectRadiusWhat happens
Fireball646 mComplete vaporisation
20 psi blast2.3 kmHardened structures destroyed, ~100% fatalities
5 psi blast4.6 kmMost buildings collapse, widespread fatalities
3rd-degree burns6.9 kmFull-thickness burns to exposed skin
500 rem radiation2.4 kmLethal dose without medical care
1 psi blast10.4 kmWindow breakage, light damage, glass injuries

How Rio de Janeiro can prepare

With a population density of 5,300 people/km², Rio de Janeiro's outcome would hinge on the first hour. The guidance is identical everywhere: get inside, stay inside, stay tuned. A basement or the core of a large concrete building cuts fallout exposure by a factor of 10 or more, and radiation decays fast — dose rates fall ~90% within the first 7 hours and ~99% within two days.

Check your exact address in Rio de Janeiro →
Model disclaimer: These are research-grade estimates from open scaling laws (Glasstone & Dolan, 1977), not predictions. Actual outcomes depend on burst height, weapon choice, weather, terrain and sheltering. In any real emergency follow official civil-defence guidance.

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