CHAPTER 14
NUCLEAR POWER: PROMISE AND PROBLEMS

I. Nuclear Power Current and Future Status

A. Number of power plants today: 442 worldwide with 45 under construction.

B. Nuclear power generates about 17% of the world's electricity.

C. Why is the number of power plants declining in most countries?
1. Economics
a. More costly than estimated
b. Costs have increased so that in 1993 dollars it is as expensive as solar for
generating electricity
2. Opposition
a. Radiation can lead to damaged DNA
b. Costs
Fig. 14.4 In 1997, those countries lacking fossil fuel reserves tended to be the most eager to employ nuclear power. (Data from International Atomic Energy Agency.)
Fig. 14.2 Since the early 1970s, when orders for plants reached a peak, few utilities called for new plants, and many have canceled earlier orders.
II. Nuclear Fuel Cycle

A. Mining
1. Human Health Concerns
a. Miners
b. General public: tailings used as landfill; living near tailing piles
2. Environmental Concerns

B. Enrichment
C. Fuel Element Fabrication

D. Nuclear Power Plants
1. Difference between fission and fusion
2. What is a chain reaction?
3. Radioactive Products/Daughter Products
4. Radioactive Emissions
a. Radioactive particles:
·Alpha particles
·Beta particles
b. Electromagnetic radiation
·Gamma rays
5. Radioactive Decay and Half-Lives
6. How does a Power Plant Operate?
a. Water moderator
b. Neutron-absorbing material
c. Fuel rods - approximately one-third replaced each year
d. Heat transfer system
e. Cooling system
f. Redundant safety systems
Fig. 14.5 Nuclear energy is released by (a) fission, the splitting of certain large atoms into smaller atoms, or (b) fusion, the fusing together of small atoms to form a larger atom. In both cases, some of the mass of the starting atom(s) is converted to energy.
Fig. 14.6B This figure shows a self-amplifying chain reaction leading to a nuclear explosion. Since two or three high-energy neutrons are produced by each fission, each may cause the fission of two or three additional atoms
Fig. 14.7 In the core of a nuclear reactor, a large mass of uranium is created by placing uranium in adjacent tubes, called the fuel elements. The rate of the chain reaction is moderated by inserting or removing rods of neutron-absorbing material (control rods).
Fig. 14.6C In a sustaining chain reaction, the extra neutrons are absorbed in control rods so that amplification does not occur.
Fig. 14.8 The double-loop design isolates the pressurized water from the steam-generating loop that drives the turbogenerator.
E. Waste Products: What Are They?
1. Low level wastes
2. High level wastes

F. Reprocessing of Wastes

G. Waste Disposal
1. High Level
a. All fuel rods are still in cooling ponds at commercial nuclear facilities
b. Yucca Mountain
c. Concerns
·Geological active area
·Intrusion of water
·Distances for wastes travel

2. Low Level
a. Each state/region is to develop a facility
b. Controversy
c. What do we do with medical wastes from nuclear medicine if no site is
acceptable?

H. Plant Decommisioning
1. Options
a. Entombing
b. Mothballing
c. Dismantling
2. Costs
Fig. 14.9 The nuclear power option assumes perfect containment of radioactivity and the availability of some method for waste storage and disposal.
Fig. 14.10 Nuclear fission results in the production of numerous unstable isotopes, the radioactive wastes. They give off potentially damaging radiation until they regain a stable structure.
Fig. 14.11 This figure shows (a) A substance with a half-life of one year, starting with 24 units; (b) the same substance starting with 48 units; (c) a substance with a half-life of two years.  (Note that decay of a radioisotope never equals 100%.)
III. Accidents

A. Chernobyl
B. Three Mile Island
C. Local Facilities
1. Rancho Seco
2. Browns Ferry
3. Diablo Canyon

IV. Comparison of  Coal versus Nuclear for Electricity Generation
Fig. 14.14 Advanced light water reactors have many safety features.