The National Aeronautics and Space Administration (NASA) has awarded BWXT Nuclear Energy a $18.8 million contract to initiate conceptual designs for a nuclear thermal propulsion reactor in support of a possible future manned mission to Mars. BWXT Nuclear Energy is a subsidiary of nuclear components, fuel and services provider BWX Technologies, which is based in Lynchburg, Virginia.

The reactor, based on low-enriched uranium (LEU) fuel, would be part of a nuclear thermal propulsion (NTP) rocket engine designed to propel a spacecraft from Earth orbit to Mars and back. According to NASA, an NTP system can cut the voyage time to Mars from six months to four and "safely deliver human explorers" by reducing their exposure to radiation. That also could reduce the vehicle mass, enabling deep space missions "to haul more payload".

Rex Geveden, BWX Technologies' president and CEO, said yesterday: "We are uniquely qualified to design, develop and manufacture the reactor and fuel for a nuclear-powered spacecraft. This is an opportune time to pivot our capabilities into the space market where we see long-term growth opportunities in nuclear propulsion and nuclear surface power."

A nuclear thermal propulsion reactor
(Image: BWXT)

The contract includes initial reactor conceptual design, initial fuel and core fabrication development, licensing support for initial ground testing, and engine test program development. Work under the contract is expected to continue through 2019, subject to annual Congressional appropriations and options exercised at customer discretion, the company said.

Nuclear thermal power for spaceflight has a number of advantages over chemical-based designs, it said, primarily providing higher efficiency and greater power density resulting in lower propulsion system weight. This would contribute to shorter travel times and lower exposure to cosmic radiation for astronauts.

According to a NASA statement on 2 August, researchers at its Marshall Space Flight Center in Huntsville, Alabama, say NTP technologies are "more promising than ever", and have contracted with BWXT Nuclear Energy "to further advance and refine those concepts".

Part of NASA's Game Changing Development (GCD) Program, the NTP project "could indeed significantly change space travel", NASA said, largely due to its ability to accelerate a large amount of propellant out of the back of a rocket at very high speeds, resulting in a highly efficient, high-thrust engine. In comparison, a nuclear thermal rocket has double the propulsion efficiency of the Space Shuttle main engine, "one of the hardest-working standard chemical engines of the past 40 years". That capability makes NTP "ideal for delivering large, automated payloads to distant worlds", it said.

Itself part of NASA's Space Technology Mission Directorate, the GCD Program advances space technologies that may "lead to entirely new approaches" for its future space missions and "provide solutions to significant national needs".

Sonny Mitchell, NTP project manager at Marshall, said in the 2 August statement: "As we push out into the solar system, nuclear propulsion may offer the only truly viable technology option to extend human reach to the surface of Mars and to worlds beyond."

Given its experience in developing and delivering nuclear fuels for the US Navy, BWXT will aid in the design and testing of a "promising" LEU-based nuclear thermal engine concept and 'Cermet' - ceramic metallic - fuel element technology, NASA said.

During this three-year, $18.8-million contract, the company will manufacture and test prototype fuel elements and also help NASA properly address and resolve nuclear licensing and regulatory requirements. BWXT will aid NASA in refining the feasibility and affordability of developing an NTP engine, delivering the technical and programmatic data needed to determine how to implement this promising technology in years to come, it added.

The company's new contract is expected to run through to 30 September 2019 and BWXT said its work on the contract would start immediately.

NASA noted that nuclear-powered rocket concepts are not new.

"The USA conducted studies and significant ground tests from 1955 to 1972 to determine the viability of such systems, but ceased testing when plans for a crewed Mars mission were deferred. Since then, nuclear thermal propulsion has been revisited several times in conceptual mission studies and technology feasibility projects. Thanks to renewed interest in exploring the Red Planet in recent decades, NASA has begun new studies of nuclear thermal propulsion, recognising its potential value for exploration of Mars and beyond," it said.

In late September, the NTP project will determine the feasibility of using LEU fuel. The project then will spend a year testing and refining its ability to manufacture the necessary Cermet fuel elements. Testing of full-length fuel rods will be conducted using a "unique" Marshall test facility, it said.

Researched and written
by World Nuclear News

Date: Friday, 04 August 2017
Original article: BWXT-c