Valar Atomics is in negotiations to raise $1 billion in a new funding round.
The investment would value the small nuclear reactor startup at approximately $5 billion pre-money.
Sequoia Capital is reportedly in discussions to lead the financing.
The three-year-old company achieved a self-sustaining nuclear reaction at its Utah test site on July 14.
Valar Atomics recently partnered with Nvidia to demonstrate its reactor powering AI chips.
The startup aims to provide dedicated power sources for data centers.