Page 39 - Materials Chemistry, Second Edition

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10 Waste Management Practices: Municipal, Hazardous, and Industrial
required by a number of states. Also appealing to industry are substantial cost savings when the
above wastes do not have to be managed as hazardous. The implementation of universal waste pro-
grams varies from state to state; for example, some states have included their own universal wastes
in addition to those listed by federal regulations.

1.2.6 CONSTRUCTION AND DEMOLITION DEBRIS
Construction and demolition (C&D) debris is waste material produced during construction, reno-
vation, or demolition of structures. Structures include residential and nonresidential buildings as
well as roads and bridges. Components of C&D debris include concrete, asphalt, wood, metals,
gypsum wallboard, and roofing. Land-clearing debris such as tree stumps, rocks, and soil are also
included in C&D debris.

1.2.7 RADIOACTIVE WASTE
Radioactive wastes are a specialized category of industrial wastes. The main generators are elec-
tricity-producing nuclear plants, nuclear waste reprocessing facilities, and nuclear weapons facili-
ties. Radioactive wastes are also produced by research and medical (e.g., pharmacological)
procedures. Radioactive wastes are, by definition, unstable; they contain atoms with nuclei that
undergo radioactive decay. Energy is naturally released from the nucleus to convert it into some sta-
ble form. Energy can be emitted as particles or electromagnetic waves. Particles include alpha par-
ticles, which are composed of two protons and two neutrons (the equivalent of a helium atom
stripped off its planetary electrons), and beta particles, essentially identical to electrons. Gamma
radiation is a form of electromagnetic energy similar to light or x-rays.
A major concern with radioactive materials (including wastes) is their capability of causing
effects from a distance; in other words, particles, and particularly gamma radiation, can travel for a
measurable distance. Gamma waves can penetrate matter including living tissue. The alpha, beta,
and gamma forms of radioactive energy are designated “ionizing radiation” because they can ion-
ize other matter, i.e., create a charge on a previously uncharged atom or molecule. This effect is
potentially hazardous to health, as ionized nucleic acids (DNA and RNA) can lead to genetic muta-
tions and cancer.
High-level radioactive wastes are generated in nuclear plants by the fission of uranium nuclei
in a controlled reaction. The Nuclear Regulatory Commission (NRC) defines high-level radioactive
waste as (10 CFR Part 72):
1. the highly radioactive material resulting from the reprocessing of spent nuclear fuel,
including liquid waste produced directly in reprocessing and any solid material derived
from such liquid waste that contains fission products in sufficient concentrations; and
2. other highly radioactive material that the Commission, consistent with existing law,
determines by rule requires permanent isolation.

Spent uranium fuel is an example of a highly radioactive waste and contains many other
radionuclides. Generators of this waste include commercial nuclear plants that produce electricity,
nuclear waste reprocessing facilities, and nuclear weapons facilities. These wastes are highly regu-
lated and rigorously managed; there are strict licensing requirements for the storage of spent nuclear
fuel and high-level radioactive waste (10 CFR Part 72).
Due to the inherent hazards, the disposal of high-level wastes is fraught with controversy. For most
nuclear-technology countries, the primary disposal choice involves some form of sophisticated burial
in deep, stable geologic formations. In the United States, the Yucca Mountain site, located about 90
miles north of Las Vegas, Nevada, is under consideration as the primary choice for a repository. The
site appears to have the approval of engineers due to the presence of volcanic tuff deposits, substan-
tial depth to groundwater, and an arid environment. The Yucca Mountain site had been approved by