Mv Ramana

M.V. Ramana is with the Nuclear Futures Laboratory and the Program on Science and Global Security at Princeton University. He is the author of The Power of Promise: Examining Nuclear Energy in India (Penguin Books, 2012). He is a member of the International Panel on Fissile Materials and the Science and Security Board of the Bulletin of the Atomic Scientists. This article is based on numerous technical papers with collaborators and his book.

He can be contacted at mvramana@gmail.com

[Article courtesy: WISE Nuclear Monitor, No. 759 ]

“I don’t see much sense in that,” said Rabbit.
“No,” said Pooh humbly, “there isn’t. But there was going to be when I began it. It’s just that something happened to it along the way.”
− A. A. Milne in Winnie the Pooh

Along with China, India has currently the most ambitious nuclear power program in the world. In September 2009, while speaking at the inauguration of the International Conference on the Peaceful Uses of Atomic Energy in New Delhi, Prime Minister Manmohan Singh stated that India could have 470 gigawatts (GW) of nuclear power capacity by 2050. To put this in perspective, the current nuclear capacity in the country − more than 60 years after the atomic energy program was established − is just 4.78 GW, a mere 2.25% of the total electricity generation capacity.

In addition to the ambition, another noteworthy feature of India’s plans for expanding nuclear power is the centrality of fast breeder reactors. Fast breeder reactors are thus termed because they are based on energetic (or “fast”) neutrons and because they produce (or “breed”) more fissile material than they use. In the projections put out by the Department of Atomic Energy (DAE), breeder reactors comprise over 90% of the nuclear capacity by mid century. But breeders have been shown to be unreliable in many countries and reliance on such a technology makes it likely that nuclear power will never become a major source of electricity in India.

Three Phase Program

The DAE’s interest in breeder reactors dates back to 1954 at least. By that time, some leading domestic scientists had started criticizing India’s establishment for not having constructed any reactors despite relatively large budgets. In response, the DAE resorted to what has become a standard response: painting a glorious future with impressive projections of massive quantities of nuclear electricity. This is in line with nuclear programs elsewhere, although the degree to which the future is stressed in comparison to the present is more extreme in India.

The DAE’s plan from 1954 involved what it called the three-phase or three-stage nuclear program. The first phase calls for the use of uranium to fuel heavy water reactors, followed by the reprocessing of the irradiated spent fuel to extract plutonium.

In the second stage, the accumulated plutonium is used in the nuclear cores of fast breeder reactors. If these nuclear cores were to be surrounded by a blanket of uranium, the reactors would produce more plutonium; if the blankets were to use thorium, they would produce uranium-233, another fissile isotope of uranium.

The third stage involves breeder reactors using uranium-233 in their cores and thorium in their blankets. The primary goal was to base the growth of nuclear power on thorium − of which India had plenty − rather than uranium, which is relatively scarce. In turn, the rationale for that goal was to put forth a strategy for building a large nuclear capacity based on indigenous resources − that is, the pursuit of what is often termed energy security these days.

On the basis of this three-phase strategy, the DAE announced that there would be 8 GW of nuclear power in India by 1980. By the early1970s, the prediction was that by 2000, there would be 43 GW of nuclear capacity, with the bulk of it being constituted by fast breeder reactors. Reality, however, was quite different. Actually installed capacity was about 0.6 GW in 1980 and 2.72 GW in 2000, with no contribution from breeders. The latest incarnation of these projections is the 470 GW mentioned earlier.

Construction and Operating Experience

Despite this sixty-year history, there is only one operating breeder reactor in India − the Fast Breeder Test Reactor (FBTR). A Prototype Fast Breeder Reactor (PFBR) is being constructed.

According to the DAE, the “FBTR has provided valuable experience… and the confidence to embark upon construction of” the PFBR. The confidence is misplaced. The budget for the FBTR was approved in 1971 and it was anticipated that it would be commissioned by 1976. But the reactor finally attained criticality only in October 1985, and the steam generator began operating only in 1993. Not only was the reactor much delayed, but the FBTR’s operations have been tarnished by several accidents of varying intensity. Overall, the reactor’s performance has been mediocre: it took 15 years before the FBTR even managed 50-plus days of continuous operation at full power and during the first 20 years of its life, the reactor had an availability factor of about 20%.

None of this is exceptional, and breeder reactors around the world have been very unreliable, in part because of their use of liquid (molten) sodium to cool the reactor cores.

The experience with the FBTR confirms the words of Admiral Hyman Rickover, the founder of the U.S. naval nuclear submarine program, who observed that breeder reactors were “expensive to build, complex to operate, susceptible to prolong shutdown as a result of even minor malfunctions, and difficult and time-consuming to repair.”

Even before the FBTR came on line, the DAE started making plans for the larger PFBR and the first expenditures on the reactor started in 1987-88. Again, the DAE’s plans were delayed for technical reasons and construction of the reactor finally began in 2004. The reactor has, like other Indian reactors, experienced severe time and cost overruns. The currently projected start date, as of February 2013, for commercial supply of power is September 2015 (with experimental operations starting a year earlier), five years later than initially anticipated. As of now, the estimated construction cost has increased from Rs. 34.9 billion to Rs. 56 billion.

Safety Concerns

There is a fundamental safety problem that is generic to nuclear reactors that use fast neutrons. In thermal reactors, which use slow neutrons, the core is typically in its most reactive configuration when it is operating normally at full power. Any change to this configuration in an accident would therefore decrease the power being produced. For example if the fuel is dispersed, neutrons escape from the core without inducing further fissions, thus reducing the power output. Instead if the fuel collapses into a smaller volume, the resulting decrease in moderation of neutrons makes their energies less suitable for fission and consequently reduces the power.

In fast reactors by contrast, collapsing the fuel into a reduced volume increases the rate at which the chain reaction occurs. If this were to happen quickly enough, the pressure in the fuel would rise fast enough to lead to an explosion (i.e., a rapid release of energy). The mechanism behind such a release of energy is essentially the same as in a nuclear weapon explosion, though the energy releases are very much lower. Such a “core disassembly accident” has therefore been an important concern in the fast reactor design community ever since the first such reactors were constructed.

This concern has been exacerbated by various design choices made by the DAE, in particular its choice of a positive value for what is called the coolant void coefficient. The Chernobyl reactor also had a positive coolant void coefficient and that was one of the underlying reasons for the devastating 1986 accident. As a result, nuclear engineers around the world have preferred reactor designs that have negative void coefficients. Going against that trend, the DAE came up with a design for the PFBR that has a relatively large and positive void coefficient, roughly one and a half to two times that of similar fast breeder reactors.

What’s worse, the PFBR’s containment design does not protect adequately against severe accidents that could conceivably occur. Equally troubling is the inadequacy of the safety analyses performed by DAE, which utilize very optimistic assumptions. Calculations by a former colleague and I show that if one were to use less optimistic assumptions applicable to severe accidents that are easily conceivable, the resulting pressure on the containment structure would be much higher than what it is designed for, and the containment’s integrity would be compromised leading to the escape of radioactivity into the surroundings.

High Electricity Costs

Economics, not safety, has likely played an important role in the choice of PFBR design. The DAE has argued that imposing the economic cost of a higher plutonium inventory associated with lowering the void coefficient is not justified. Likewise the choice of containment design also appears to be directly linked to cost reduction efforts. In general “minimizing capital cost” was one of the design objectives for the PFBR and the DAE has asserted that “the capital cost of FBRs will remain the most important hurdle” to rapid deployment of breeder reactors.

The irony is that this unsafe breeder reactor is still too costly, and a former colleague and I calculated that electricity will be about 80% more expensive than corresponding costs from the DAE’s heavy water reactors. And this is with the original cost estimates, before applying the roughly 60% cost increases that have been reported.

The main reason for higher electricity cost at the PFBR is its requirement for plutonium. The PFBR design requires an initial inventory of about two tons of plutonium in its core and about a ton of plutonium every year for refueling at 75% capacity factor. Because plutonium is about 30,000 times more radioactive than uranium-235, the fissile component of uranium fuel, safety precautions are required during fabrication of fuel. Globally, just fabricating mixed oxide (MOX) fuel containing both plutonium and uranium has proven to be several times as expensive as the total cost of uranium fuel. Therefore, reactors fueled by plutonium are not cost competitive at current uranium prices and breeders do not make economic sense until the price of uranium increases dramatically.

How much of an increase is needed? For the optimistic base case, the PFBR becomes competitive with other nuclear reactors when uranium prices go up by a factor of about seven when compared to today’s prices. Significantly larger quantities of (poorer quality) uranium ore will be available at these prices. Regardless of whether an expansion of nuclear power based on high-cost uranium makes sense, our calculations demonstrated that the DAE has not undertaken the most elementary economic analysis necessary to justify the breeder program.

Projection Errors

In addition to the risks of catastrophic accidents associated with breeder reactors, and the high cost of electricity that they might generate, these will not constitute a major source of electricity in India anytime in the short or medium term future because the DAE’s projections have simply not accounted properly for the future availability of plutonium.

The problem is that the DAE has not taken into account the lag period between the time a certain amount of plutonium is committed to a breeder reactor and when it reappears along with additional plutonium for refueling the same reactor, thus contributing to the start-up fuel for a new breeder reactor. It is simply impossible to construct breeders at the rate the DAE envisions because reactors cannot operate when they don’t have plutonium to fuel them. In addition, the DAE has resorted to various unrealistic assumptions about dealing with radioactive spent fuel and recovering plutonium.

If one were to use a consistent methodology with more realistic assumptions, the projected nuclear capacity would decrease to about 20% of the DAE’s projections. Even this estimate assumes that there will be no delays because of infrastructure and manufacturing problems, economic disincentives due to the high cost of electricity, or accidents.

The Weapons Connection

There may be another reason for the DAE’s attraction to breeder reactors − their potential contribution to the nuclear weapons program. This came out quite clearly during the course of negotiations over what was dubbed the US-India nuclear deal, where in an ostensibly civilian agreement, much of the DAE’s efforts were aimed at optimizing its ability to make fissile material for the nuclear arsenal within various constraints, especially the shortage of uranium. Most prominently, the DAE’s focused a lot of attention on keeping the fast breeder program outside of safeguards. In a prominent interview to a national newspaper, the head of the DAE said: “Both, from the point of view of maintaining long-term energy security and for maintaining the minimum credible deterrent, the fast breeder programme just cannot be put on the civilian list. This would amount to getting shackled and India certainly cannot compromise one [security] for the other.”

In parallel, the DAE did not classify its reprocessing plants or its stockpile of reactor-grade plutonium as civilian. This allows for the possibility that breeder reactors like the PFBR are used as a way to “launder” unsafeguarded reactor-grade plutonium, both the historical stockpile as well as future production at unsafeguarded reprocessing plants, into weapon-grade plutonium. While reactor-grade plutonium is consumed in the core of the PFBR, in the radial and axial blankets weapon-grade plutonium is produced. Based on neutronics calculations for a detailed three-dimensional model of the reactor, a colleague and I estimated that 92.4 kg and 52 kg of weapon-grade plutonium will be generated in the radial and axial blankets (93.7% and 96.5% Pu-239) respectively in the PFBR each year at 75% capacity factor. If the blanket fuel elements are reprocessed separately rather than jointly with the core fuel elements, then the plutonium contained in them can be used for weapons. Such a strategy would increase the DAE’s fissile material production capacity several-fold.

Conclusion

The history of breeder reactors in India offers important lessons for other countries. Today, more than five decades after ambitious plans involving breeders were announced, and decades of well-funded and politically-backed research and development, nuclear power constitutes only a trivial fraction of overall electricity generation in India. Some part of the blame for this state of affairs should go to the DAE’s obsession with breeders and reprocessing. In the future, there is no reason to expect breeders to operate reliably, produce cheap electricity, or constitute a major fraction of electricity generation. Even for those favoring nuclear power, breeder reactors make little economic sense.

There are two main reasons why India’s nuclear establishment continues to be interested in breeder reactors. The first is that once you ignore the sorry history of these reactors around the world, breeders offer the DAE the ability to promise to produce large amounts of electricity based on limited domestic resources of uranium. As I argue in my book The Power of Promise, this ability has been one of the two pillars of the DAE’s institutional and political power. The attractiveness of this characteristic is that it serves the interests of India’s elite who are looking to unbridled consumption requiring ever-increasing amounts of energy. This is why the DAE has continued to attract high levels of funding for decades despite its many failures.

The second pillar of the nuclear establishment’s political and institutional power is its ability to produce the means to manufacture nuclear weapons, wherein, again, breeder reactors can potentially contribute significantly. This ability to produce nuclear weapons allows the DAE to offer something that no other energy technology offers, and the resultant political power has been used by the DAE to bypass democracy. On many occasions, the DAE has resorted to the argument that, due to national security considerations, it cannot be held accountable by various organs of the government. This has been true not just in India but in many other countries, and constitutes another unattractive feature of nuclear power.