Goodbye in a Mushroom Cloud

Please ignore spelling errors below.

It's the end of World War 3 and maybe the end of humanity. The war that's been going on for 20 years and is ending in mushroom clouds. Two RadioKids; Finley and Phillip aswell as a man called General Toms were sent in to save people in some of the biggest cities. It goes downhill when Finley finds something out... something that screws their whole plan over.

This was for a writing competition at school. It had a 700 word limit. I decide to make a sort of prologue to a dystopian / Sci-fI novel idea I had. These are the inspirations:

The Hunger Games

The Bobiverse Trilogy by Dennis E Taylor (book)

The Girl With All the Gifts by M.R. Carey (book)

Limetown by Two-Up (Podcast)

The Box by .... The Box Podcast(...?) (Podcast)

Book idea summery (don't read unless you've read the short story):

After a World War that ended with all sides nuking and Bombing each other, the world has become an uninhabitable wasteland and the safest place to go is Chernobyl. But problems arise when the sarcophagus, that has been up for almost 30 years now starts to heavily decay. An enclave of survivors (possibly the only ones) are concerned that if the structure collapses it could release a high amount of radiation or worse, cause another explosion. It's up to Finley, a radio kid with the ability to read minds, Sanda Johnson, a British engineer, and ION, Sanda's Artificial Intelligence to figure out a way to fix it.
Together, they must save the enclave.
They must save Chernobyl.
They must save the world.