TerraPower gets OK to start construction of its first nuclear plant

Source: Ars Technica

Construction Approval

On Wednesday, the US Nuclear Regulatory Commission announced that it had issued its first construction approval in nearly a decade. The approval will allow work to begin on a site in Kemmerer, Wyoming, by TerraPower, a company financially backed by Bill Gates. This does not guarantee operational approval, but it is a critical step for the company.

TerraPower’s Natrium Reactor

Design Collaboration

The Natrium design has been developed jointly with GE Hitachi.

Key Features

• Sodium‑cooled fast‑neutron reactor – uses liquid sodium for cooling and heat transfer, avoiding the high‑pressure steam used in water‑cooled reactors. Sodium is highly reactive when exposed to air or water, which introduces safety considerations.
• Fast‑neutron spectrum – can potentially consume isotopes that would otherwise become long‑lived radioactive waste in traditional reactor designs.

Size and Capacity

• Electrical output: 245 MW (compared with roughly 1 GW for most current nuclear plants).
• Temporary peak output: up to 500 MW.

Integrated Energy Storage

Instead of using the heat extracted by the sodium to boil water directly, the plant transfers that heat to a salt‑based storage material. This stored thermal energy can be:

• Converted to electricity on demand, or
• Stored for later use, allowing the plant to operate alongside variable renewable generation and mitigate price competition.

The storage system also enables the temporary 500 MW output capability.