Rebalancing the nuclear debate through education

Better physics teaching with a particular emphasis on radioactivity and radiation science could improve public awareness through education of the environmental benefits and relative safety of nuclear power generation, according to leading Brazilian scientist Heldio Villar. He suggests that it might then be possible to have a less emotional debate about the future of the industry that will ultimately reduce our reliance on fossil fuels.

To environmental activists, nuclear power and environmental preservation are two antagonistic concepts. Nevertheless, nuclear power can generate huge amounts of electrical and heat energy with minimal impact on the planet, particularly in terms of much lower carbon emissions and pollution than is seen with power generation based on burning fossil fuels. Because of this cultural clash, activists have prognosticated doom for a world if we pursue the nuclear energy option, leading to public distrust of the nuclear industry and its relatives, nuclear research installations and particle accelerators.

“The introduction of the theoretical bases of radioactivity, radiation physics and nuclear power plants in the environmental education curricula will certainly result in a greater awareness of the public towards the reality surrounding radiation and radioactivity,” says Villar of the University of Pernambuco, who not surprising also works for Brazil’s Nuclear Energy Commission. “This initiative, coupled with a more realistic approach towards nuclear risks on the part of nuclear regulators and licensers, has the potential to make nuclear applications – not only in electric energy production but in other areas – more palatable to a public squeamish of another Three Mile Island or Chernobyl and the specter of nuclear weapons, rendering it more prepared to reap the benefits thereof.”

Ironically, in the 1950s and 1960s, nuclear power was once hailed as the best option for an energy-starved world. Nuclear reactors were seen as modern, reliable and, above all, capable of producing electricity ‘too cheap to meter’. Into the 1970s, the oil crisis sparked the first major interest in going nuclear on a much wider scale. However, even before Three Mile Island, activist groups such as Greenpeace were sounding unwarranted alarm bells and popular movies such as the China Syndrome, which does not have a disastrous ending, were fuelling the anti-nuclear movement.

Villar points out that it is widely accepted that Brazil and several other nations, are entirely capable of launching successful nuclear power programs, given their expertise, the availability of nuclear fuel and the pressures such as a lack of coal and the rising price of oil. “Electrical energy is scarce and obviously expensive,” says Villar, “a situation seen in several other countries.” Supposed “green” solutions, such as hydroelectric power, which has already been fully exploited in Brazil, as well as gas turbines, solar and wind power, tidal power and biomass, do not represent a cheaper alternative to nuclear he asserts.

Villar, H. (2011). The ‘threat’ of radioactivity: how environmental education can help overcome it International Journal of Nuclear Knowledge Management, 5 (3) DOI: 10.1504/IJNKM.2011.042006

Periodic table trends

The Periodic Table of the Chemical Elements is an ultimate and fundamental of nature or merely a tool for creating useful patterns in chemistry. Discuss.

It could be a critical essay title from an undergraduate course in the philosophy of chemistry but it isn’t, it’s a real life periodic debate that rages on year after year among chemists who hope to find an ultimate form for the Periodic Table and those who suggest that any form will do as long as it is useful iin education and research. I recently published a summary of the state of the art regarding such forms and the stance of those who see them as nothing more than aesthetic variations on the theme and those who regard them as taking us a step closer to such an ultimate form for the Table. You can read the periodic debate over how the Table is complete, but not finished in my June Research Highlight column on Chemistry Views. A more in-depth version of the article in which UCLA’s Eric Scerri offers up a radically different PT and in which Martyn Poliakoff of Periodic Table of Videos fame rebuts the notion that such efforts are taking us closer to the ideal Periodic Table.

The aesthetics and ethics of elemental periodicity

It seems that the Periodic Table is in trouble. Well, not trouble exactly but aside from revisions to the atomic weights announced recently and the official adding to the Table of two “new” elements, 114 and 116, the poetically named and fleeting ununquadium and ununhexium, there is a debate bubbling like a reflux condenser about what precisely the Periodic Table is and what form it should take.

For decades chemistry educators and laboratory technicians have sat back and watched the corners of their good-old Periodic Table wall charts curl, each element in its box, trapped forever, with no alchemical chance to move. But that might soon change. Of course, there have been lots of attempts to rebuild the periodic table over the past 150 years. For instance, there are those, such as museum exhibit designer Roy Alexander, who suggests that in the twenty-first century, the 2D is not to be, and that it is high time that chemists made the switch to a 3D format for the Periodic Table. After all, if it’s good enough for Hollywood and Wimbledon, it should be good enough for chemists.

Spiralling into control

There are those who have attempted to create intriguing spiral Periodic Tables, circular efforts and even fractal charts. One Table dating back to the 1930s considers the sub-atomic particle, the neutron, as itself a element and lists the noble gases twice. In the 1920s Charles Janet built a stepped Periodic Table, which was much wider than the standard PT and would inevitably have been less than convenient for textbook publishers and wall chart printers alike.

Others suggest that subtle rearrangements of various elements would make the Periodic Table more intuitive and circumvent various discrepancies that have arisen as nuclear understanding evolved. Chemical philosopher Eric Scerri of the University of California Los Angeles is among that number. He is devising an alternative approach to elemental organization, which he suggests takes us closer to an ultimate version of the PT. Scerri’s argument for change is based on the fact that Periodic Table arose from the discovery of triads of atomic weights, but he thinks chemists would be better served if they were to recognize the fundamental importance of triads of atomic number instead. His new Periodic Table takes this phenomenon into account.

Scerri stuff indeed

The revision of the Periodic Table to this Scerri form is perhaps especially pertinent given that atomic mass varies according to isotope ratio (neutron count, in other words), whereas atomic number (proton count) is fixed for each element. In it, listings of electron shells follow an ordered pattern, so that the halogens form the first column on the left, topped by hydrogen, the noble gases are the second column, topped by helium. The alkali metals and the alkaline earth metals follow, then the block of transition metals. The semi-metals and the non-metals then form the final four columns. As if this restructuring of the groups were not controversial enough, it is the logical placements of hydrogen and helium that stirs chemical emotions. In relocating H and He, Scerri recreates the atomic number triads of He-Ne-Ar and H-F-Cl; these are not visible in the conventional PT.

However, not everyone is convinced by helium’s placement. Among them is American chemist Henry Bent, known for “Bent’s Rule” of molecular orbitals used by organic chemists and variously written as: “atomic ‘s’ character tends to concentrate in orbitals that are directed toward electropositive groups and atomic p character tends to concentrate in orbitals that are directed toward electronegative groups.” Bent would prefer to see helium atop beryllium in the otherwise “normal” PT layout. He argues that although helium seems to fit perfectly at the top of the noble gases its presence there breaks several of the rules. For instance, a Periodic Group’s first member is never the member of a primary (vertical) triad. This rule holds for 30 of the 32 Groups when He is above Ne. The two exceptions are He-Ne-Ar and Be-Mg-Ca. Move He above Be and the rule now holds for all 32 Groups.

Getting the He-Be-gee-bees

The He-Be debate is something of an aside to the philosophical debate that Scerri has unleashed by being quite so adamant that all the various Periodic Table arrangements are moving towards an ultimate version. He doesn’t wish to imply that his version is the essential, final version of which he speaks, but it is perhaps a step closer than the conventional PT we all know and love. “My belief is that there is one true and objective periodic classification even if we have not yet arrived at it,” he says.

Others, such as Philip Stewart, a longstanding fan of the spiral Periodic Table painted by artist Edgar Longman for the Science Exhibition of the 1951 Festival of Britain, based on chemist John Drury Clark’s 1933 original, is not convinced. Stewart argues that to search for “The Ideal Periodic Representation” is to take leave of the messy world of everyday bodies and drift off into Platonic mysticism. Software developer Melinda Green who developed a fractal Periodic Table for educational use agrees and says that an ultimate PT does not exist. Our perspective inevitably distorts reality, she says, any arrangement is purely subjective. “Neither the periodicity nor any classification is intrinsic to nature,” explains Green. “Periods of what? Where do these classes come from? They come from us to suit our particular purposes,” she says.

Atomic number is perhaps the only intrinsic property of the elements, as suggested by Scerri too, but, adds Green, this is only fundamental by our subjective definition of the term “element” rather than it representing something ultimate about the universe as Scerri’s reasoning would suggest. “I don’t believe that there are any ways to describe anything about the universe without a relative position from which to describe,” adds Green. “Every description requires a describer. Subjectivity is not just an annoyance, it is the source of all meaning.”

Chemistry’s rich pageant

Stewart suggests that we should think of the rich variety of images that have been proposed in the last 150 years as “something more like an art exhibition than a competition to achieve perfection. So, is the elemental menagerie, nothing more than an art gallery? Martyn Poliakoff thinks so. Poliakoff is a professor of chemistry at the University of Nottingham, England, who works on supercritical fluids but has gained fame recently for his involvement in a science engagement project known as the Periodic Table of Videos that has gone “viral” on the internet. Poliakoff takes an entirely pragmatic approach to the PT. “I regard the PT as a tool like a hammer and, just like other tools, you have different forms for different purposes (e.g. a claw-hammer and a mallet). There just isn’t a “right” and “wrong” form. The different forms highlight different aspects,” he says. He suggests that the different forms can be useful, however. “I think that these weird forms of the PT often serve a purpose by highlighting some aspect of the elements that one might not otherwise have noticed,” he says.

However, Scerri is convinced that there is something more fundamental to the ultimate PT. “It concerns me that scientists can express ‘relativistic’ [aesthetic] views on something as important as the Periodic Table,” he says. “It is, after all, the most basic, profound and deep classification that has ever been discovered.” The way we perceive the elements and their relationships with each other is fundamental to understanding matter, Scerri believes. The elements are natural entities, they are not building blocks we have constructed for our convenience. The patterns they obey follow objective rules, laws if you will, that are not decided by us and so do not succumb to the whim of the designers of novel Periodic Tables, stepped, 2D, 3D, spiral, fractal or otherwise.

Practical conclusion

Ever the pragmatist, Poliakoff points out a fact of periodic life that may be inescapable in efforts to raise the Periodic Table to some higher position in science. “In the end, I think that one should remember that Mendeleev devised the Periodict Table for a textbook to help rationalize the mass of facts in inorganic chemistry and to make them easier to teach,” he says. “For me, the PT remains just that, a tool to help reduce the complexity, not a metaphysical truth that has a correct form, as yet to be discovered.”

  • Scerri stuff indeed (sciencebase.com)
  • Two new elements officially added to periodic table (theglobeandmail.com)

How low can you go?

We’re repeatedly advised to switch off electrical devices, like TVs and DVD players at the mains outlet rather than leaving them in standby mode, to turn to compact fluorescent bulbs and to turn them off when illumination is no longer necessary, to do our laundry at lower temperatures, to run the dishwasher only when it’s full, and to avoid using energy-hungry power showers. All those kilowatts add up to a lot of power wasted if we don’t.

According to a new study into energy use in the UK, by following this advice we might be reducing our carbon footprint a lot more than we thought. Conversely, those who don’t follow the advice might be wasting far more energy than the government thinks and so contributing more to carbon dioxide emissions and so anthropogenic global warming and climate change. Writing in the journal Energy Policy this month, Adam Hawkes, of the Grantham Institute for Climate Change at Imperial College London, has calculated that the figures used by government advisors to estimate the possible carbon dioxide reduction possible might be 60% too low.

Hawkes points out that power stations that supply electricity vary in their carbon dioxide emission rates, depending on the fuel they use: those that burn fossil fuels (coal, gas and oil) have higher emissions than those driven by nuclear power and wind. In general only the fossil fuel power stations are able to respond instantly to changes in electricity demand. He says that the government should keep track of changing carbon emission rates from power stations to ensure that policy decisions for reducing emissions are based on robust scientific evidence.

Hawkes used 60 million data points for electricity production each half-hour period by each power station in Great Britain from 2002 to 2009 and calculated the emissions for each different type of generator by examining government data showing their average annual fuel use. He then calculated emissions rates attributed to a small change in electricity demand from these two data sets.

SPT86-montalto-power-station (Credit: David Bradley)
Montalto power station (Credit: David Bradley)

His new study suggests that excluding power stations with low carbon emission rates, such as wind and nuclear power stations, and focusing on those that deal with fluctuating demand would give a more accurate emission figure. Hawkes’ calculations show that, 0.43 kilograms of carbon dioxide per kilowatt hour of electricity consumed is 60 percent lower than the actual rates observed between 2002 and 2009 (0.69 kilograms of carbon dioxide per kilowatt hour), meaning that policy studies are underestimating the impact of people reducing their electricity use.

“One way governments are trying to mitigate the effects of climate change is to encourage people to reduce their energy consumption and change the types of technologies they use in their homes,” Hawkes says. “However, the UK government currently informs its policy decisions based on an estimate that, according to my research, is lower than it should be.”

Links

Energy Policy, 2010, online