Gods in this universe inhabit a higher plane of existence. Their spirits inhabit large, humanoid forms upwards of 30ft, and watch over humanity by protecting it from outside threats. On occasion, a god must enter the mortal plane for various reasons. However, there are certain conditions that must be met. A god cannot simply possess a human, for their divine essence would destroy it not long after. Therefore, special human bodies must be constructed from scratch to contain the godly essence within and allow gods to walk among mortals. These bodies are made using Godtech, highly advanced technology that only gods have access to.
These bodies are 8ft tall and look human on the outside, but inward they are heavily modified, possessing advanced organs that humans do not. Inside these bodies is an organ called the core, which contains the soul of a god. These cores operate similar to a miniature nuclear reactor that powers the body and contains the divine essence inside it, preventing it from leaking out into the environment. These bodies are powerful and highly durable, and provide for almost instant regeneration. However, gods can still be killed if they have taken enough damage, which leads to a problem.
When a god dies, the core containing its spirit ceases to function and becomes unstable, causing a rupture. The explosion alone would destroy a significant part of the surrounding environment. The true danger, however, is the divine radiation which would spread to a larger area due to factors such as wind currents. This radiation would spread further and further, causing damage to lesser creatures unable to withstand the power, killing hundreds or even thousands of people. Lesser still would be the rampant mutations of those touched by divine power, which can lead to disastrous consequences for them.
I need a way to limit the effects of a failed nuclear reactor from blowing up a huge area so that only the body is destroyed, while prevent the spread of divine radiation from turning the surrounding environment from becoming holy Chernobyl. How can I make this happen?