PBRs can halve global warming CO2

In February, 2007, the Intergovernmental Panel on Climate Change published the report Climate Change 2007 which gave further evidence that (a) the climate is warming, and (b) human activities are part of the cause. Most of the press coverage focuses on the warming, the shrinking glaciers, starving polar bears, and rising oceans. The evidence that man-made greenhouse gasses actually cause the global warming is harder to communicate. The report quantitatively models the contributions of various human-caused components, such as CO2, N2O, and CH4, of which CO2 is the largest.

To my mind, the clearest evidence is the above chart, published by NASA. Over the last 170,000 years atmospheric CO2 levels and global average temperatures have changed in tandem. The two graphs are too similar to be attributed to chance. The frightening aspect, at the top right, is the sudden increase in CO2 levels of the last decades. This portends a similar increase in temperatures. Pebble bed reactors can decrease future CO2 emissions. Here's how.


Quads of fossil fuels burned annually in the US


One quad is one quadrillion [10^15] BTU per year. The first post in this blog has a DOE energy flow chart indicating consumption of 55 quads of US fossil fuel plus 29 quads of imported petroleum. These 84 quads are burned, producing CO2. US coal, primarily for electric power, accounts for 23 quads of this. We can begin to cut CO2 emissions by replacing coal electric power with nuclear electric power.

The previous post showed how pebble bed reactors can be built in factories, much as Boeing builds airliners. Boeing builds at least one airliner per day. Let's suppose we build just one PBR module each week to replace coal-burning electric power. The thermal efficiency of a coal power plant is about 33%, so it takes 3 times as much energy in as it sends out. Here's how many quads of fossil fuel one 100 megawatt PBR module can save.

100 x 10^6 watt [1 megawatt = 106 watts]
x 3.4 BTU / watt hour
x 24 hours / day
x 365 days / year
x 3 [to account for 33% efficiency]
x 1 quad / 10^15 BTU / year
= 0.0089 quad

So building one PBR module per week displaces 0.0089 x 52 = 0.46 quads of fossil fuel energy every year thereafter. The bar chart above illustrates the concept. The displaced quads can be from coal, crude oil, or natural gas.

Deploying pebble bed reactors can reduce the US-produced CO2 that contributes to global warming, by half, in this century.

Technology has improved since 1970s nukes

Three dimensional computer aided design technologies help designers lay out and test designs for products ranging from tiny heart stents to huge airliners. Above is another presentation of the conceptual PBR layout done by MIT researchers using such tools. Some of the Seabrook cost overruns were due to design errors, which caused piping runs to collide during construction. With today's 3D-CAD such expensive errors can be prevented.

Design technologies have improved phenomenally during the three decades since today's operating US nuclear plants were designed. Just consider information technology. The designers of today's nukes didn't have personal computers, nor Microsoft software, nor data base management. Nor was there email, optical fiber, the internet, nor search engines.

We all know that computer speeds have been doubling ever 2.5 years or so. Computers are many thousands of times more capable than those of 30 years ago. The impact on engineering and simulation is phenomenal. Scientific computing now lets us better understand the origins of the universe, and the structure of matter. Finite element analysis, together with 3D-CAD, breaks solid models down into thousands of sugar-cube-like elements and simulates all inter-element flows of heat, electricity, fluids, stresses, etc. to predict the behavior of the whole. Software products like Fluent add dynamics and multi-phase characteristics. MATLAB does mathematics for engineers and economists. AutoCAD, Pro/E, and Catia compete to offer designers better and better 3D design, modeling, simulation, mockup, production, and testing tools.

Manufacturing management has also progressed since the 1970s with Statistical Process Control, GE's 6-Sigma process management, Total Quality Management, Good Manufacturing Process, and ISO 9000. Materials Resource Planning evolved to become company wide, to manage purchasing, production, scheduling, shipping, quality management, accounting, and management reporting, in a single, integrated, real-time management system. Enterprise-wide information systems like SAP and Oracle provide leading companies with integrated, real-time, operational control and management. Manufacturing management systems help keep Boeing from delaying airliner delivery for lack of a single one of it's 500,000 different parts, for example.

A decade ago Boeing Aircraft received the Smithsonian-Computerworld award for the Boeing 777. It was the first example of such product design and development with computer assisted design and engineering tools continuing through computer-managed manufacturing. When the airliner assemblies were brought together they fit! The 777 was the first airliner to fly without half a ton of shims.

Production lines benefit cost and quality



A standardized design and construction process will enable the production of PBR units rapidly and economically, with high quality standards. Earlier US nuclear power plants were individually designed, licensed, and constructed. In France, where nuclear plants supply most of the country's electric power, standardized designs are the rule. Standardizing the design and production process for PBRs will lead to many benefits.

• One type-certification for many plants
• Reduced costs
• Faster delivery times
• Strong quality controls
• Continuing product improvement

The PBR production process can emulate Boeing's.

• Production line
• One unit per day
• Standardized units
• Computer-aided design, engineering, manufacturing
• $ 100-200 million per unit
• Life safety paramount

In summary, since US nuclear power plants were built in the 1970s, information technology and manufacturing management have improved dramatically, promising even safer nuclear power in the future.