# Terrestrial Energy Inc.

**Type:** Company (publicly traded advanced nuclear reactor developer)  
**Ticker:** NASDAQ: IMSR  
**Founded:** Canadian-origin, targeting US commercial deployment  
**Status:** Active development and NRC licensing process  
**Focus:** Integral Molten Salt Reactor (IMSR) design and commercialization

## Overview

Terrestrial Energy is the first publicly traded molten salt nuclear reactor developer, having gone public via SPAC merger in 2025. The company is developing the IMSR, an advanced reactor design that uses fluoride salt as both fuel and coolant.

## Technology

**IMSR Specifications:**
- 822 MWth / 390 MWe (net 44% thermal efficiency)
- Operating temperature: 600-700°C
- Suitable for industrial process heat applications
- Uses lithium fluoride-based salt as combined fuel and coolant
- Distinct from other advanced reactors: does not use CSP-derived nitrate salt as integral design element (unlike Natrium's molten nitrate salt storage or Kairos KP-FHR's nitrate salt intermediate circuit)
- Optional external coupling with nitrate salt thermal storage for grid integration possible but not core to design

## Active Projects

- **Project TETRA:** Pilot reactor for IMSR development (DOE-supported)
- **Project Tefla:** Pilot salt production facility

## Regulatory Progress

- **September 2025:** NRC issued Safety Evaluation approving IMSR Principal Design Criteria
- **April 23, 2026:** Submitted foundational safety analysis topical report to NRC (final stage before Safety Evaluation Report issuance)
- **Target:** First commercial IMSRs licensed and operating in early 2030s

## Business Model

Public market accountability through NASDAQ listing, contrasting with private tech-company-backed models of TerraPower (Natrium) and Kairos. Pursuing fleet-scale deployment efficiency through NRC topical report process, where a single Safety Evaluation Report can be referenced across multiple future licensing applications.

## Timeline

- **2025** — Company went public via SPAC merger (NASDAQ: IMSR)
- **2025-09** — NRC issued Safety Evaluation approving IMSR Principal Design Criteria
- **2026-04-23** — Submitted NRC topical report on safety events IMSR is designed to withstand (final stage before SER issuance)