R 004 1yrctax

20 0

20 0

Figure 7.38 Summary of relative sensitivities of key metrics to (linear) carbon taxation, with the ratio of present-value of total carbon taxes to the present-value of gross world product, fTAX, being used to express the impact of a range of (linear) carbon-tax rates, CTAX($/tonneC/15yr), and with metrics measure in the year 2095 and referenced to the BAU/BO fUTC = 1.0, CTAX=0.0 $/tonneC/yr) basis scenario in the year 2095; Table 7.8 gives values used to perform the normalization, as well as key definitions (Krakowski, 1999).

Figure 7.38 Summary of relative sensitivities of key metrics to (linear) carbon taxation, with the ratio of present-value of total carbon taxes to the present-value of gross world product, fTAX, being used to express the impact of a range of (linear) carbon-tax rates, CTAX($/tonneC/15yr), and with metrics measure in the year 2095 and referenced to the BAU/BO fUTC = 1.0, CTAX=0.0 $/tonneC/yr) basis scenario in the year 2095; Table 7.8 gives values used to perform the normalization, as well as key definitions (Krakowski, 1999).

This optimistic statement is contingent first upon continued operation of LWRs, with an open uranium fuel chain with ever-improving operating costs and decreased annualized capital-cost payments (Phases I and II of Sec. 7.4.2.1, Fig. 7.20). However, it is likely that one or more of the alternative reactors and fuel cycles discussed in Phase III (Fig. 7.20) will prove more economical of both electricity production, environmental impact, and, ultimately, of resource use, while further emphasizing the advantage of nuclear energy as a sustainable energy source.

It seems likely that a prerequisite for this optimism is a resolution of the public concerns discussed in Section 7.3.2. In particular, "re-engineering" of nuclear systems by itself will be ineffective in recovering public acceptance of this technology. The reality of, and the rate of approaching, any viable nuclear-energy future will depend on limits to growth as established by:

• The rate at which barriers to public acceptance of this technology are lowered;

• Energy demand shifts and growths at the global level; and

• Economic (financing) limitations.

Fuel resource limitations are often mentioned in this context, but Sections 7.1.4 and 7.2.6. show that real resource limitations do not exist for nuclear fission; for the kinds of growth scenarios depicted on Fig. 7.19, once-through use of low-enriched uranium should be adequate for the 21st century; any strong role for nuclear energy in significantly mitigating CO2 emissions will require breeder reactors or economical seawater uranium coupled with FSBs (to control plutonium inventories), or the introduction of the Th-U fuel cycle (see Fig. 7.23).

The authors believe that a future for at least one hundred years is possible with present and evolutionary LWR technology (Phases I and II, Fig. 7.20), (Wilson, 2000). This future would involve a nuclear deployment rate of ~90 GWe/yr after the year 2030, leading to a final capacity of 5000 GWe by the year 2100. Nonetheless, the following approaches to a long-term nuclear energy future should be explored in Phase III, as nuclear energy strives for true sus-tainability:

• The long-term need for and economics of fissile-fuel breeders versus uranium-from-seawater/IACS (plutonium burning dedicated/LWR-supporting IFRs or ADSs);

• Use of the thorium resource in an LWR versus (plutonium) breeder reactors; and

• If a bridge to a viable nuclear energy cannot be constructed, the technological (nuclear-materials inventory), and overall infrastructural implications of a nuclear phase out (Beck, 1994; OECD, 1998b; Krakowski et al., 1998b; Krakowski, 1999; IAEA, 1999) should be explored on both regional and global levels. This scenario presents a particularly significant challenge for those who wish to abandon nuclear energy.

If nuclear energy is to help in stabilizing CO2 emissions to present rates (or below, if atmospheric concentrations are actually stabilized), the following will be required:

• Nuclear plant capacities of 5000 GWe by the year 2100, corresponding to deployment rates of 90 GWe/yr after ~2030;

• Depending on uranium resource assumptions, breeder reactors, based on either conventional plutonium breeders or a high-burn-up thorium cycle (most likely based on LWRs for electricity generation or HTGRs for process heat applications), will have to be deployed sometime after 2050 at a rate largely determined by the availability of startup plutonium; and

• Applications of nuclear energy for the production of transportable liquid fuels [clean(er) coal gasification first, leading ultimately to hydrogen generation, perhaps using coal/CaO thermal-chemical cycles, along with CO2 sequestration (Lackner and Ziock, 2001)] to satisfy a growing demand for non-electric energy represent future options and challenges.

Even in view of these projections, substantial increases in renewable energy sources, particularly solar and to a lesser extent biomass, will still be needed, depending largely on land-use competition.

An important issue is how to get there from here. One possible route might be to allow the nuclear industry effectively to die, and then to restart completely with new organizational infrastructure and new perspectives. This approach is similar to the "stagnate and revive" scenario suggested by the NEA/OECD study (Fig. 7.19 - NEA-III, OECD, 1998b). The build rates under "revive" conditions can be technically challenging (OECD, 1998b). Another approach might be to recognize that if the presently operating nuclear power plants can be kept running, the operating cost average of 1.9 cents per kWeh is much less than the "market entry" cost of 2.5 cents per kWeh of combined cycle natural gas. Brewer and Hanzlik (1999) have emphasized this possibility, and discussed who might pay for the return on capital already expended. A more likely scenario might be that nuclear power dies in some regions of the world, and flourishes in others, with past nuclear inventor-vendors becoming future customers of an irresistibly attractive new nuclear technology.

Finally we note that we can get close to meeting the Kyoto agreements if we wish to use nuclear energy and be in a position to make further reductions in CO2 emissions thereafter. It need not be expensive. But we must be active and not merely talk about it. For nuclear energy to make significant contributions in a future diverse energy mix to mitigating global warming, strong progress in Phase III (Fig. 7.20) will be an absolute requirement (resolution of the frontend resource and back-end waste issues). Most importantly, ideas that recover and retain the competitiveness of safest and non-proliferating nuclear energy must be developed and connected to a global, long-term E3 context; resolution of waste, economics, proliferation, and safety issues must be folded into an effective, self-consistent, and transparent package that the public can accept and trust.

ACC ACRS ACT ADS

Solar Power

Solar Power

Start Saving On Your Electricity Bills Using The Power of the Sun And Other Natural Resources!

Get My Free Ebook


Post a comment