AP300 by Westinghouse: status and timeline

Milestones

Next · NRC design certification application submitted

AP300 design unveiled2023Complete.
Amentum partnership signed5 Aug 2026Complete.
NRC design certification application submittedTarget Q1 2027Not yet reached.
NRC design certification approvalTarget Q1 2029Not yet reached.
First construction permits issuedTarget Q1 2030Not yet reached.

Upcoming

Q1 2027NRC design certification application submitted (next)
Q4 2028First utility selects AP300
Q1 2029NRC design certification approval
Q1 2030First construction permits issued

Current obstacles

NRC design certificationMulti-year review validates every aspect against regulatory standards.
Cost competitivenessMust prove viable against large reactors and renewable energy sources.
Supply chain scalingComponent suppliers need to scale production for distributed reactor sites.

Physics limits

Thermal efficiency limitLight water reactors limited to ~33% thermal efficiency; cannot improve without changing coolant.

How it works

3 parts

Design

Single-loop simplified

Eliminates one steam generator and pump versus AP1000; reduces complexity.

Safety

Passive cooling

Gravity and natural circulation for emergency cooling with multiple safety systems.

Construction

Modular assembly

Factory-built components reduce on-site construction time and weather exposure.

Spec sheet

Spec	AP300
Electrical output	300 MW^R (reported)
Thermal output	~1000 MW^E (estimated)
Target capital cost (single-unit plant)	$1 billion^R (reported)
Fuel assemblies	121 (17x17 configuration)^R (reported)
Refueling cycle	4 years^R (reported)
Design lifetime	80+ years^R (reported)

^R reported by the company · ^E our estimate

Peer comparison

Fission peers

Spec	AP300	China National Nuclear Corporation Linglong One (ACP100)
Electrical output	300 MW^R (reported)	125 MW^R (reported)
Thermal output	~1000 MW^E (estimated)	385 MW^R (reported)
Design lifetime	80+ years^R (reported)	60 years^R (reported)

^R reported by the company · ^E our estimate

About Westinghouse

The team behind AP300

Westinghouse

AP1000, AP300, nuclear reactors, APX platform, small modular reactor

Westinghouse develops the AP1000 (1200 MW) and AP300 (300 MW) reactors. US deployment backed by $17.5B DOE loans and Amentum partnerships.

Westinghouse is headquartered in Cranberry Township, Pennsylvania and is led by President and CEO Dan Sumner (appointed April 2026).
Six AP1000s operating globally; 11 under construction; selected for Poland, Ukraine and Bulgaria.
DOE committed $17.5B (June 2026) for long-lead items on up to 10 AP1000s across five utilities.

westinghousenuclear.com (opens westinghousenuclear.com)Company profile →

Founded: 1886140 yrs
Headquarters: United States
Status: Private
Valuation: private
Works in: EnergyFission
Coverage: 2 programs · 2 updateslatest 5 Aug 2026checked 10 Oct
Customers: Tennessee Valley Authority (opens tva.gov)
Partners: U.S. Department of Energy (opens energy.gov)Amentum (opens amentum.com)
People: Dan Sumner (opens info.westinghousenuclear.com)President and CEO

Spec

AP300

Electrical output

300 MW^R (reported)

Thermal output

~1000 MW^E (estimated)

Target capital cost (single-unit plant)

$1 billion^R (reported)

Fuel assemblies

121 (17x17 configuration)^R (reported)

Refueling cycle

4 years^R (reported)

Design lifetime

80+ years^R (reported)

Spec

AP300

China National Nuclear Corporation Linglong One (ACP100)

Electrical output

300 MW^R (reported)

125 MW^R (reported)

Thermal output

~1000 MW^E (estimated)

385 MW^R (reported)

Design lifetime

80+ years^R (reported)

60 years^R (reported)