PEBBLE BEDS 

To the Editor: As a South African born and bred who has taken U.S. citizenship and can now call myself a bona fide African-American, I read your article about the South African pebble bed reactor (February) with great interest and not a little pride. Through the international Gen IV program, I have been involved in a small way in the development of design methods for the next generation of nuclear plant, and—small world—I discovered my niece to be working with PBMR on the South African end of the same program.

It should be sobering to the more advanced countries of the world that, while the debate over nuclear power goes on-and on—one small country has gone ahead and done it. Maybe the pressure of 20 million impoverished inhabitants who need a quick leg up has something to do with it.

This is not the first, or even the second time South Africa has led the way in implementing technology which everyone acknowledges to have been around for years but simply has not been implemented because of too much "planning." The second is the practical implementation of oil from coal. The South African company SASOL has now been producing oil from coal for nearly 50 years.

The third advance is in the development of mine-resistant military vehicles. MRMVs, called variously Buffels or Caspirs, were developed and used very successfully in South Africa since the Angola war of the 1980s. These vehicles are being sold worldwide—even to U.S. military contractors in Iraq and elsewhere, but not, interestingly, to the U.S. forces themselves.

South Africa appears to be the accidental beneficiary of the "bumblebee effect." According to the experts, this is an insect incapable of flight-but nobody told the bumblebee, so it flies anyway.

Douglas L. Marriott
South Lebanon, Ohio

Editor's note: The Generation IV program is an international program to develop and circulate knowledge relevant to the design of the next generation of nuclear power plants. The author said his work in connection with Gen IV was in the area of design methods for very high temperature operation, as in the very high temperature helium-cooled pebble-bed reactor in South Africa.

To the Editor: The thermal efficiency of the proposed 165 MW nuclear power plant ("Pebbles Making Waves," February) is 41 percent, somewhat better than the usual 32 percent.

I am not impressed. When the entropy of refining the pebbles and disposing of the spent fuel is considered, the efficiency of the program drops precipitously.

Entropy can be defined as the inverse of sustainability.

Imagine 165 MW generated by 100 wind turbines, rated at 2 MW each, scattered wherever they can be connected to the power grid, far enough apart that most of them are always turning. This sustainable source of energy generates no entropy or carbon dioxide. It probably costs less to build and never needs refueling.

John L. Hill
Albuquerque, N.M.

NO POLITICS

To the Editor: As I was reading the article "Wedge Factor" by Jeffrey Winters (October 2007), I realized that the author is not an engineer. Taking a broader look at the article, I realized that he was assuming that global warming was occurring and that our primary mission was to reduce our production of carbon dioxide.

I could argue against this, but this has already been done recently in letters to the editor.

The pattern is that non-engineers are writing scientific articles. I expect this level of performance from newspapers and television, but not from a magazine whose audience is highly technically sophisticated. I suggest that they write articles in which they glean information from experts, rather than portraying themselves as the experts. They also come too close to politics. As an example of avoiding politics, Automotive Engineering (Society of Automotive Engineers) has several articles on how to meet regulatory requirements. They never discuss the merits of the regulations.

Martin Marcus
Silver Spring, Md.

NATURAL CAUSES

To the Editor: I have read with interest over the last year or so many articles and letters discussing global warming and its causes.

Recently, there have been broadcasts on The Learning Channel (TLC) and Discovery (DSC) regarding this issue. One of the most recent and compelling was aired on DSC. The show presented several scientifically gathered facts. The scientists gathered samples using proven techniques from areas all over the world. Briefly, they found evidence of drastic global warming 250 million years ago, 55 million years ago, and 11,500 years ago. In each of these cases, there was a 20°F rise on the Earth within a 100-year period.

We should note two important facts. First, during each of these events, it is obvious that human-produced carbon emissions were not a factor (unless aliens were involved!). Second, within the last 100 years our records indicate there has only been a 1°F rise in global temperatures.

We may very well be headed for global warming. There is significant data showing how much humans contribute. Data should be acquired showing how much CO2 is released from natural causes, such as:

1. Naturally occurring fires, such as the one that burned for six months in northern Florida;

2. The fire that burned in Greece;

3. Any of the fires that consistently burn out West;

4. Release of gases from volcanoes that are erupting.

Instead of our society and politicians spending time and resources on preventing something that may be beyond our control, why not use our knowledge and technology to prepare for the effects that warming will produce?

Steve Greenbaum, P.E.
Cudjoe Key, Fla.

WASTE NOT

To the Editor: Dave Erskine (Letters, February) was absolutely correct about how silly it would be to license more nuclear plants without a good way to manage the wastes. Well, in 1996 some top people at the Argonne National Laboratory announced that they had the solution to this problem—one which had been proven in a 20 MW experimental reactor in Idaho that was able to convert spent fuel from conventional reactors into electricity. In fact, it could generate 95 times more electricity than was extracted from the fuel the first time.

Has anybody heard about this and/ or wondered what happened to it? Maybe with all the concern about atmospheric pollution and global warming, it may prove worthwhile for someone to check it out.

Bob Balhiser
Helena, Mont.

TAKING ISSUE

To the Editor: In "Managing the Unpredictable" (March), the author gets a handle on the issue.

In my experience, part of the problem is that sometimes the people who know the most about a problem are the last people to be listened to, often because they are young and/or low in the hierarchy. In a crisis, management sometimes has too much data from too many conduits, and they may choose to ignore the wrong ones. Maybe they just won't listen to bad news. Or maybe the new guys really are wrong.

As for getting an M.B.A. vs. an M.S.E. ("To a Higher Degree"), the author does not mention opportunity costs or the availability of either program in many markets. Even schools that have these programs may be lukewarm or even hostile to non-full-time day students. Distance learning has yet to be accepted in all applications.

Finally, the idea of interviewing departing engineers to retain what they learn that isn't written down any-where would seem charming on a good day. But I haven't seen many engineers hang on long enough to retire as engineers. Mostly, they get laid off, and their attitude is, "Whatever I know I'll take with me, and I'll take it to my death before I tell any of it to you."

I will be interested to see how much flak the second letter to the editor, "No Preference," generates.

Overall, the issue was very good, and the articles complemented each other well.

Ronald Corradin
St. Paul, Minn.