Plutonium - doe-hdbk-1188-20060139

DOE-HDBK-1188-2006

138. PLUTONIUM. A heavy, radioactive, metallic element with the atomic number 94. It is produced

artificially by neutron bombardment of uranium. Plutonium has 15 isotopes with atomic masses ranging

from 232 to 246 and half-lives from 20 minutes to 76 million years. Its most important isotope is fissile

plutonium-239. [Derived from NRC Glossary, AHD]

139. POLLUTION PREVENTION. The use of materials, processes, and practices that reduce or

eliminate the generation and release of pollutants, contaminants, hazardous substances, and waste into

land, water, and air. For the Department of Energy, this includes recycling activities. (See waste

minimization.) [DOE P4]

140. POLYCHLORINATED BIPHENYLS (PCBS). Any compound or a mixture of compounds of a

family of chlorinated organic chemicals that were formerly manufactured for use as coolants and

lubricants in transformers, capacitors, and other electrical equipment. The manufacture of PCBs

stopped in the United States in 1977 because of evidence that they build up in the environment and

cause harmful effects. PCBs in water, for example, build up in fish and marine mammals and can reach

levels thousands of times higher than the levels in water. It is not known whether PCBs cause cancer

in people, but the Department of Health and Human Services has determined that PCBs may

reasonably be anticipated to be carcinogens. The Environmental Protection Agency has classified all

PCBs as Group B2, possible human carcinogens.[Derived from ATSDR, EPA IRIS]

141. PREVENTION OF SIGNIFICANT DETERIORATION (OF AIR QUALITY) (PSD).

Regulations established to prevent significant deterioration of air quality in areas that already meet

National Ambient Air Quality Standards (NAAQS). Specific details of PSD are found in 40 CFR

51.166. Among other provisions, cumulative increases in sulfur dioxide, nitrogen dioxide, and PM-10

levels after specified baseline dates must not exceed specified maximum allowable amounts. These

allowable increases, also known as increments, are especially stringent in areas designated as Class I

areas (e.g., national parks, wilderness areas) where the preservation of clean air is particularly

important. All areas not designated as Class I are currently designated as Class II. Maximum

increments in pollutant levels are also given in 40 CFR 51.166 for Class III areas, if any such areas

should be so designated by EPA. Class III increments are less stringent than those for Class I or

Class II areas. [See National Ambient Air Quality Standards (NAAQS).] [Derived from 40 CFR

51.166]

142. QUALITY FACTOR. A multiplying factor applied to absorbed dose to express the biological

effectiveness of the radiation producing it. The numerical values of quality factor are given as a

function of the linear energy transfer in water for the radiation producing the absorbed dose. [NCRP

94]

143. RAD. A unit of radiation absorbed dose (e.g., in body tissue). One rad is equal to an absorbed dose

of 0.01 joule / kilogram (1 rad = 0.01 gray). (The joule is the SI unit of energy, abbreviated as J.)

[Derived from 10 CFR 20.1004]

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