Frequently Asked Questions

X-energy is a leading developer of advanced nuclear reactors and fuel technology designed to establish a new standard in clean, safe, reliable energy. X-energy’s intrinsically safe Xe-100 high-temperature gas reactor and TRISO-X particle fuel expand applications for nuclear technology into grid, industrial, and AI applications. Together, X-energy’s technology drives enhanced safety, broader industrial applications, and scalable deployment when compared with other SMRs and conventional nuclear.

X-energy is advancing its initial proposed four-unit Xe-100 plant at Dow’s UCC Seadrift Operations manufacturing site on the Texas Gulf Coast under the U.S. Department of Energy’s Advanced Reactor Demonstration Program. X-energy’s second project, the Cascade Advanced Energy Facility, is advancing with Energy Northwest in collaboration with Amazon, part of a larger strategy with Amazon to bring more than five gigawatts of new nuclear online by 2039. Centrica is pursuing deployment in the United Kingdom through a Joint Development Agreement, with Hartlepool identified as the preferred first site.

X-energy’s Xe-100 is a high-temperature gas reactor that is designed to produce 565°C steam—enabling industrial applications like chemical manufacturing, refining, and hydrogen production that require temperatures beyond what light-water reactors (~300°C) can deliver. X-energy’s TRISO-X fuel is engineered to withstand extreme temperatures, enabling passive safety at high operating temperatures.

The U.S. Department of Energy selected X-energy in 2020 as one of two awardees for the Advanced Reactor Demonstration Program (ARDP) from many applicants, providing $1.2 billion in cost-shared funding for X-energy’s first deployment of the Xe-100, and a first TRISO-X fuel fabrication facility. The program is designed to de-risk first-of-a-kind deployment, stimulate commercial interest, and reaffirm U.S. leadership in advanced nuclear technology.

A high-temperature gas-cooled reactor uses helium gas as a coolant instead of water, enabling operating temperatures of 700-950°C compared to ~300°C for conventional reactors. The Xe-100 uses graphite as a moderator and TRISO fuel particles embedded in graphite pebbles. This design enables both electricity generation and high-grade industrial process heat production. HTGRs have operated safely for over 50 years globally, with demonstrated operational experience in the United States, United Kingdom, Germany, Japan, and China.

Tri-Structural Isotropic (TRISO) coated particle fuel consists of a uranium kernel surrounded by four microscopic ceramic layers — each engineered to trap and retain fission products. A TRISO particle acts as its own containment vessel, and is designed not to melt even at temperatures exceeding 1,600°C. This resilience is why TRISO fuel has been described by the U.S. Department of Energy as “the most robust nuclear fuel on Earth.”

X-energy’s HTGR and TRISO fuel technology leverages physics-based passive safety designed to ensure safe, reliable operations. If cooling is lost, the reactor naturally shuts down through negative temperature coefficient — as the temperature rises, fission automatically slows without operator action. The reactor’s low power density and use of graphite as a moderator allows passive heat dissipation, eliminating reliance on pumps, external power, or operator intervention. This intrinsic safety approach helps enable a 400-meter emergency planning zone compared to 10 miles for traditional reactors, enabling siting at industrial facilities, or in closer proximity to areas of large load growth.

HTGRs like X-energy Xe-100 are designed to provide clean baseload power for electric applications, targeting 95%+ availability over a 40-60-year operational life. The Xe-100 is designed to ramp output from 40-100% capacity in minutes, enabling grid flexibility to complement intermittent renewable energy sources. The compact 400-meter emergency planning zone enables more flexible siting closer to areas of large load growth. Continuous online refueling eliminates extended outages, and the modular 80 MWe design allows incremental capacity additions matched to actual demand growth.

The Xe-100 is designed to deliver industrial-grade heat and steam at temperatures exceeding 565°C, a critical temperature threshold for chemical manufacturing, petroleum refining, cement production, steel manufacturing, and other heavy industrial processes. The reactor’s intrinsic safety case and 400-meter emergency planning zone enables co-location directly at operating industrial complexes, providing on-site energy generation that eliminates transmission losses and insulates operations from external grid disruptions.

The Xe-100 is deployed as a four to twelve-unit plant, with each reactor capable of coming online independently upon completion. This allows end users to phase in capacity one unit at a time, aligning new generation with demand growth and matching power supply to real-world load expansion. The Xe-100’s advanced design also enables the efficient use of air-cooling systems, significantly reducing overall water usage, and offering greater siting flexibility as compared to conventional reactors.

X-energy starts recruiting for the summer internship program in early fall. We have campus visits scheduled across the U.S., and open internship positions are posted to the Careers Page by November 30th.

All internship opportunities are fully on-site at one of our offices (Rockville, MD or Oak Ridge, TN). We believe this gives Interns the maximum benefits of a professional experience.

Most internship opportunities are part of the summer program. Any available off-cycle internships can be found on our company website or by contacting our Recruiting department ([email protected]).

It varies from year to year. Our internship classes for the last four years have ranged from 4 to 17 interns. We typically hire Summer Interns for X-energy headquarters in Rockville, Maryland, as well as our TRISO-X office in Oak Ridge, Tennessee.

We occasionally have entry-level positions for new graduates. Any full-time career opportunities are posted on our company career page.

All Interns must submit a letter of recommendation from a professor or academic advisor. This document can be added to your application or sent directly to our Recruiting department ([email protected]).

Our internships are open to any student with U.S. work authorization. However, applicants must be in compliance with the Export Controls regulations of the United States of America. You can review a list of Generally Authorized Destinations at eCFR :: Appendix A to Part 810, Title 10.