Nuclear propulsion is the fastest way to send a manned mission to Mars, as the United States proposes to do in the late 2030s. But nuclear power can also be useful for other activities in space that require more electricity than solar panels can currently provide, such as harvesting ice from the Moon to provide drinking water and generate rocket propellant for future lunar explorers.

NASA and the National Academies of Sciences, Engineering, and Medicine have outlined the benefits of nuclear propulsion for space exploration and made important proposals to develop the technologies needed to send humans to Mars. As useful as this work is, space nuclear power isn’t just about propulsion. The dynamic commercial space and national security sectors can also benefit from nuclear capabilities and have an important role to play in developing dual-use technologies that have both military and civilian applications, though with some caveats to ensure human safety.

While a National Academies report published in February advocates for the use of nuclear power in propulsion, nuclear power for non-propulsion applications is becoming increasingly attractive as the commercial space sector seeks to expand its activities. It would be prudent to discuss and establish policy on the use of space nuclear power now, so that policy and safety concerns can be fully addressed during the development proposed by NASA and the National Academies. The United States and the world have important decisions to make about whether, when, and how to use nuclear power in space.

Space nuclear propulsion represents a significant advance over current propulsion technologies such as chemical propulsion and solar electric propulsion. Chemical propulsion produces high forces but requires a large percentage of the spacecraft’s mass to be devoted solely to carrying fuel. Electric propulsion requires relatively less fuel, but generating electrical power in space with solar panels produces low thrust and means that spacecraft need months or years to complete their journeys.

By generating electrical power with a nuclear reactor, or by directly using the heat of nuclear fission to produce thrust, future spacecraft could have a propulsion system that eliminates the downsides of current technologies. With both a high-power output and high mass efficiency, space nuclear propulsion would enable entirely novel types of space missions, such as capturing small asteroids or, as NASA plans, sending humans to Mars.

In addition to providing advanced propulsion capabilities, nuclear power would enable other space activities and allow the commercial space industry to reduce its reliance on solar panels. For example, space-based radar systems can image the ground day or night, regardless of cloud cover, but require large amounts of electrical power. Communication systems relay data across the world but are constrained by the size of their solar panels. With nuclear power, they could send more data down to Earth, or serve more customers by operating from higher orbits.

Rather than be blindsided by onrushing events and technology developments in space — not to mention the actions of ambitious foreign space competitors, both military and commercial, that may well give scant regard to safety considerations — the United States would do well to assess the space nuclear power landscape and the desirability and implications of potential space nuclear power applications. We should lead the way in identifying the types of applications that should be encouraged, those where caution may be indicated, and perhaps some applications that should be discouraged because the risks outweigh potential benefits.

Multiple federal agencies and outside stakeholders would have an interest in such an assessment. This calls for a White House-led interagency study, with input from the commercial and nonprofit sectors. At this early stage, the new Cabinet-level President’s Office of Science and Technology Policy should chair the review, with input from the National Security Council and the National Space Council. This review would clarify national policy on space nuclear power, anticipate technical and policy problems, and address them before they could seriously complicate program execution.

Interagency review should also identify measures to protect human safety. For example, the National Academies report has recommended that nuclear applications in space minimize the amount of radioactive material required, undergo sufficient testing to ensure reliable operations prior to any orbital flight, restrict reactor use until a spacecraft has achieved a safe orbit, and design all space-going reactors to automatically go into a “safe state,” in which the reactor is highly unlikely to achieve criticality and sustain a fission chain reaction, if a launch failure occurs. Nuclear power applications in low Earth orbits should be required to include back-up safety mechanisms such as redundant communications or a secondary propulsion system, as objects in these orbits are most at risk of uncontrolled reentry events like the Soviet Kosmos 954 reactor accident. In that 1978 accident, the Kosmos 954 satellite broke apart over Canada, spreading radioactive debris over the Northwest Territories and requiring a multimillion-dollar cleanup operation.

The U.S. interagency review should be tasked to address both the opportunities of space nuclear power and the potential risks and downsides, so that a coherent roadmap can be formulated to guide U.S. and allied development efforts and influence foreign developments. Inaction on these issues could allow decisions to be made by purely parochial interests both here and abroad, without consideration of larger interests. Armed with a roadmap, the United States would be better able to pursue its space interests and advocate for an effective international consensus on a safe, sensible, and productive path forward to reap the benefits that the space domain offers to all.

– edited from Bulletin of the Atomic Scientists, July 19, 2021
PeaceMeal, July/August 2021

(In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes.)

Nuclear reactions are smoldering again in uranium fuel masses deep inside an unreachable basement room of the Chernobyl Nuclear Power Plant in Ukraine, LiveScience reported. Researchers at the catastrophic 1986 explosion site have recently detected a steady spike in neutron numbers in an underground room called 305/2. A rising number of neutrons can signal new fission reactions.

The radioactive waste is smoldering “like the embers in a barbecue pit,” Neil Hyatt, a professor of nuclear materials science and engineering at the University of Sheffield, told Science magazine. And it’s possible, according to scientists, that the embers could fully ignite and result in another explosion.

“There are many uncertainties,” Maxim Saveliev, a senior researcher with the Institute for Safety Problems of Nuclear Power Plants (ISPNPP) in Kyiv, Ukraine, told Science. “But we can’t rule out the possibility of [an] accident.”

– edited from Business Insider, May 16, 2021
PeaceMeal, May/June 2021

(In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes.)

Frank N. von Hippel

One of Bill Gates’ causes is to replace power plants fueled by coal and natural gas with climate-friendly alternatives. That has led the billionaire philanthropist and Microsoft co-founder to embrace nuclear power, and building nuclear power plants to combat climate change is a prospect worth discussing. But Gates has been persuaded to back a costly reactor design fueled by nuclear- weapon-usable plutonium and shown, through decades of exper-ience, to be expensive, quick to break down, and difficult to repair.

In fact, Gates and his company, Terrapower, are promoting a reactor type that the United States and most other countries abandoned four decades ago because of concerns about both nuclear weapons proliferation and cost.

The approximately 400 power reactors that provide about 10 percent of the world’s electric power today are almost all water-cooled and fueled by low-enriched uranium, which is not weapon usable. Half a century ago, however, nuclear engineers were convinced — wrongly, it turned out — that the global resource of low-cost uranium would not be sufficient to support such reactors beyond the year 2000.

Work therefore began on liquid-sodium-cooled “breeder” reactors that would be fueled by plutonium, which, when it undergoes a fission chain reaction, produces neutrons that can transmute the abundant but non-chain-reacting isotope of natural uranium, U-238, into more plutonium than the reactor consumes.

But mining companies and governments found a lot more low-cost uranium than originally projected. The Nuclear Energy Agency recently concluded that the world has uranium reserves more than adequate to support water-cooled reactors for another century. And while technologically elegant, sodium-cooled reactors proved unable to compete economically with water- cooled reactors on several levels.

Admiral Hyman Rickover, who developed the U.S. Navy’s water-cooled propulsion reactors from which today’s power reactors descend, tried sodium-cooled reactors in the 1950s. His conclusion was that they are “expensive to build, complex to operate, susceptible to prolonged shutdown as a result of even minor malfunctions, and difficult and time-consuming to repair.” That captures the experience of all efforts to commercialize breeder reactors. The United States, Germany, the United King-dom, France and Japan all abandoned their breeder-reactor efforts after spending the equivalent of $10 billion or more each.

Today, despite about $100 billion spent on efforts to commercialize them, only two sodium-cooled breeder reactor prototypes are operating — both in Russia. India is building one, and China is building two with Russian help. But it is not clear India and China are looking only to generate electricity with their breeders; they may also be motivated in part by the fact that breeder reactors produce copious amounts of the weapon-grade plutonium desired by their militaries to expand their nuclear- weapon stockpiles.

The proliferation risks of breeder-reactor programs were dramatically demonstrated in 1974, when India carried out its first explosive test of a nuclear-weapon design with plutonium that had been produced with U.S. Atoms for Peace Program assistance for India’s ostensibly peaceful breeder reactor program. The United States, thus alerted, was able to stop four more countries, governed at the time by military juntas (Brazil, Pakistan, South Korea and Taiwan), from going down the same track — although Pakistan found another route to the bomb via uranium enrichment.

It was India’s 1974 nuclear test that got me involved with this issue as an advisor to the Carter administration. I have been involved ever since, contributing to the plutonium policy debates in the United States, Japan, South Korea and other countries.

In 1977, after a policy review, the Carter administration concluded that plutonium breeder reactors would not be economic for the foreseeable future and called for termination of the U.S. development program. After the estimated cost of the Energy Department’s proposed demonstration breeder reactor increased five-fold, Congress finally agreed in 1983.

But the dream of plutonium breeder reactors lived on in the Energy Department’s Idaho National Laboratory, and, during the Trump administration, the department agreed to back the construction at INL of a plutonium-fueled, sodium-cooled reactor, deceptively called the “Versatile Test Reactor.” The VTR is a bigger version of INL’s Experimental Breeder Reactor II, which I helped shut down in 1994 because the reactor no longer had a mission, when I worked in the Clinton administration’s White House.

The consortium that is to build the Versatile Test Reactor, at an estimated cost of up to $5.6 billion, includes Bill Gates’ Terrapower. Gates is obviously not in it for the money. But his reputation for seriousness may have helped recruit Democratic Senators Cory Booker, Dick Durbin and Sheldon Whitehouse to join the two Republican senators from Idaho in a bipartisan coalition to co-sponsor the Nuclear Energy Innovations Capabilities Act of 2017, which called for the VTR.

I wonder if any of those five senators knows that the VTR is to be fueled annually by enough plutonium for more than 50 Nagasaki bombs. Or that it is a failed technology. Or that the Idaho National Laboratory is collaborating on plutonium separation technology with the Korea Atomic Energy Research Institute at a time when about half of South Korea’s population wants nuclear weapons to deter North Korea.

Fortunately, it is not too late for the Biden administration and Congress to avoid repeating the mistakes of the past and to zero out the Versatile Test Reactor in the Department of Energy’s next budget appropriations cycle. The money could be spent more effectively on upgrading the safety of our existing reactor fleet and on other climate-friendly energy technologies.

Frank N. von Hippel is a co-founder of the Program on Science and Global Security at Princeton University’s School of Public and International Affairs and a founding co-chair of the International Panel on Fissile Materials. A former assistant director for national security in the White House Office of Science and Technology, von Hippel’s areas of policy research include nuclear arms control and nonproliferation,. His article was published in Bulletin of the Atomic Scientists, March 22, 2021, and reprinted in PeaceMeal, March/April 2021.

(In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes.)

Saudi Arabia is pushing ahead to complete its first nuclear reactor, according to satellite images that have raised concern among arms-control experts because the kingdom has yet to implement international monitoring rules. Satellite photos show the kingdom has built a roof over the facility before putting in place International Atomic Energy Agency (IAEA) regulations that allow inspectors early verification of the reactor’s design.

Saudi Arabia has repeatedly pledged that its nuclear program is strictly for peaceful purposes, but Crown Prince Mohammed Bin Salman also said the kingdom would develop a bomb if its regional rival Iran did so. Those statements made in 2018 raised a red flag within the nuclear monitoring community.

While Saudi Arabia has been open about its ambitions to generate nuclear power, less is known about the kinds of monitoring the kingdom intends to put in place.

IAEA inspectors verify the designs of facilities to ensure that nuclear material is contained within and can’t be smuggled out via trap doors or hidden tunnels. At issue is the weak and outdated set of IAEA safeguard rules called the “Small Quantities Protocol” that Saudi Arabia continues to follow.

The problem is that design-information verification has to be carried out while the reactor is being constructed, and satellite images show that a thick lattice of roof beams is now covering the 10-meter (33 feet) high steel reactor vessel.

While Saudi Arabia adheres to the Nuclear Non-Proliferation Treaty, the bedrock agreement that regulates the spread of material needed to produce nuclear fission, it still has to implement monitoring rules in line with its nuclear program development.

 – edited from Bloomberg, May 21, 2020
PeaceMeal, July/August 2020

(In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes.)