Atomic Insights

Atomic energy technology, politics, and perceptions from a nuclear energy insider who served as a US nuclear submarine engineer officer

In the news: September 1995

By

Modern Hiroshima Described

(August 7, 1995) (Knight-Ridder Newspapers) “This was supposed to have become a dead city, a toxic landscape so contaminated by radiation that nothing green would grow for generations. A nuclear desert – that’s what even some scientists saw in Hiroshima’s future. Instead, today’s Hiroshima is a thriving, flower-planted, ultramodern metropolis of 1-million people, three times the size of the city devastated by an atomic bomb 50 years ago.”

Three Nuclear Utilities Top Analyst’s Recommendations

(July 24, 1995 Wall St. Journal) Thomas E. Hamlin at Wheat First Butcher Singer mentioned Duke Power, Southern Co. and FPL Group as electric companies that should outperform their contemporaries in a competitive market. All three companies own at least four nuclear power plants that are recognized as low cost electricity producers.

Oldest Indian Nuclear Plant Will Reopen

(July 28, 1995) Shut down in April after leaking 1.5 liters of water, India’s 320-megawatt reactor at Tarapur will reopen shortly, the head of the country’s nuclear research agency said. “We have completed the review of safety procedures in the plant,” A.N. Prasad, director of the Bhabha Atomic Research Centre (BARC) told journalists on Friday. “We are in the process of securing permission to reopen the plant.”

Though leak was extremely small, its announcement sparked fears the village’ water supply was contaminated. Some villagers linked the deaths of some of their cattle to the leak.

Ukraine Demands Payments For Chernobyl

(August 8, 1995) Ukraine President Leonid Kuchma signalled growing impatience with the West’s failure to pay for the closure of Chernobyl nuclear power plant. The country claims the right to keep the plant in operation if the requested $4 billion is not paid.
Visarion Kim, a top nuclear industry official, said his authority had drawn up the plan to keep Chernobyl operating for another 16 years, including restarting a unit that is currently shut down, before Kuchma pledged last April to close the entire station by the year 2000.

Officials say the $4 billion is required to pay for a replacement thermal plant and to make provisions for the 6,000 workers currently employed at Chernobyl.

Russia Proceeding With Cuban Nuclear Reactor

(August 8, 1995) Gigorii Kaurov, a spokesman for the Russian Ministry of Nuclear Energy, announced plans to proceed with the construction of a nuclear power plant in Cuba. In June, the U.S. House of Representatives voted to reduce aid to Russia by $15 billion if the nuclear project moves forward. Kaurov rebuffed American criticism of the project, since “. . . the U.S. always expresses dissatisfaction whenever Russia begins such a project in any country whatsoever.” The Russian spokesman went on to say that Russia would welcome U.S. participation in the project

Russia Announces Mars Probe

(August 10,1995) Russian space officials announced plans for an unmanned mission to Mars that would probe beneath the planet’s surface for signs of life. The Mars-96 probe will be carried into space by a four-stage Proton rocket blasting off from the Baikonur cosmodrome in Kazakhstan. The mission is scheduled to achieve Mars orbit in November of 1996. Four small modules will be released to land on the planet’s surface.

Rocket Technology Applications: Machines With Limitless Capabilities

By

Under any circumstances, there is a very limited market for nuclear rockets. Even if space exploration is raised in the national priority list, the first mission to Mars would probably occur in about 2010. For at least a decade or more after that, trips would probably be infrequent at best.

There would be some utility to such a program; at least it would inspire a whole new generation of science and engineering students to reach for the stars. Realistically, however, it would be very difficult to attract the investments needed to develop an infrastructure to manufacture nuclear rockets if long distance space travel was the only potential market.

Governments would be the only investors and the only potential customers, and their track record of consistent support for long term projects is rather spotty.

However, the nuclear reactor heat source that is needed for a high performance rocket engine is a rather incredible device that is worth developing because of its ability to adapt to other applications. Many human needs and desires can be served if a little creative thinking is employed.

Stepping In Edison’s Shoes

First, we must understand the technical capabilities the nuclear rocket program demonstrates. Then we must think about new ways to apply those capabilities to solve existing problems, meet existing needs or fulfill difficult to achieve dreams.

This is the process that allowed the Wright Brothers to apply the new capabilities represented by lightweight internal combustion engines to the problem of powered flight. It is also the process that allowed Thomas Edison to take advantage of the invention of an efficient vacuum pump and apply it to his desire to design a long-lived electric light bulb.

Even with the materials that were available in the late 1960s, NERVA reactors were able to perform the following feats.

  • Increase power from 1 MW to 800 MW in 50 seconds
  • Start-up from source level to full power in about 80 seconds
  • Produce a thermal power of 1500 MW in a package weighing less than 6800 kg.
  • Produce coolant temperatures of 2500 ° C.

These kinds of capabilities shoot all kinds of holes in the general perception of nuclear power. Reactors are not limited to producing steady power in huge generating facilities. They are not limited to providing relatively low quality steam and poor thermodynamic efficiencies.

The numbers show that reactors can:

  • Respond at least as rapidly as any combustion heat source
  • Be made smaller than a desk
  • Be used in high efficiency machines
  • Be used as energy sources for weight constrained vehicles

Of course, rockets are normally designed to operate for very brief periods of time in comparison with a normal earth bound application. Their burn times are on the order of hours instead of months or years. It will take some modifications to make the nuclear rocket reactors into useful energy sources for economic engines.

One simple modification that could improve engine longevity considerably is to reduce coolant temperatures to about 2000 ° C. The change would make a huge difference in the rate of corrosion and erosion of the core surfaces. The best combustion engines on the market today operate at about the same temperature, so this change would not require a sacrifice in performance or efficiency compared to existing engines.

Instead of using hydrogen gas for the coolant, an inert gas like helium or maybe nitrogen could be used to reduce corrosion damage. Hydrogen is an explosive hazard and probably not very useful for a power producing engine.

Similar reactors could be used in place of the combustors in a gas turbine engine. If concerns about fission product release persisted, the exhaust gas could be recycled into the intake of the compressor.

Limitless Applications

Nuclear heated gas turbines could be used to provide power in just about every machine that is currently served by a diesel or combustion gas turbine. Imagine how exciting it could be to own a boat that allowed virtually unlimited travel at speeds only limited by hull design! Imagine having a generator at the local hospital that could run continuously without worrying about how to find fuel in the aftermath of a hurricane.

The number of potential applications are only limited by our imagination. The holy grail of the energy world is a long-lasting, responsive, low cost, emissions free energy source. Perhaps the grail has already been found, but its importance has been overlooked.

Of course, having a program to develop high performance nuclear engines with all these potential uses might just result in a lower cost trip to the Moon or Mars. Would you care to join us in the line for the first tickets?

An Inside View: How Do Nuclear Rockets Work?

By

Before learning about nuclear rockets, we should take a quick detour to review how conventional rockets work. There is a perception that rockets are fiendishly complex devices that need to be serviced and designed by people whose intelligence is far removed from that of mere mortals. Often, people even use the term “rocket scientist” to […]

U.S. Nuclear Rocket Programs

By

The Nuclear Engines for Rocket Vehicle Applications (NERVA) program officially began in 1961, when NASA issued a request for proposals and established the Space Nuclear Propulsion Office (SNPO). Various government laboratories had been studying the concept for several years, several contractors were already working on conceptual design, and space was a big topic of interest. […]