Year
The period of time beginning in January used to determine compliance with the provisions of this part. The licensee may change the starting date of the year used to determine compliance by the licensee provided that the change is made at the beginning of the year and that no day is omitted or duplicated in consecutive years.
(10CFR20.1003)
Year
The period of time beginning on or near January 1 and ending on or near December 31 of that same year used to determine compliance with the provisions of this part. The starting and ending date of the year used to determine compliance may be changed provided that the change is made at the beginning of the year and that no day is omitted or duplicated in consecutive years.
(10CFR835.2-1998)
Year
For the purpose of this standard, a Mean Tropical Year of 365.24219 days.
(ANSI N15.22-1987)
Years at risk
The difference between the time that has elapsed between radiation exposure and the endpoint of the period of observation and the minimum induction period. The maximum number of years at risk includes the period of observation plus the anticipated average remaining lifespan of the population in question minus the minimum induction period.
(NCRP 80)
Years of life lost
The expected years of life for a nonexposed person minus the expected lifetime of an exposed person.
(BEIR IV)
Yeast
A unicellular fungus.
(AM-1993)
Yellowcake
A product of uranium mills, concentrated in uranium content and suitable for shipment for further processing into fuel for reactors. The product is often in the form of a uranium oxide (U3O8).
(NCRP 118)
Yellowcake drumming
The process of putting dried yellowcake into containers (drums) for storage and shipment.
(NCRP 118)
Yield
The total energy released in a nuclear explosion. It s usually expressed in equivalent tons of TNT (the quantity of TNT required to produce a corresponding mount of energy). Low yield is generally considered be less than 20 kilotons; low intermediate yield from 20 to 200 kilotons; intermediate yield from 200 kilotons to 1 megaton. There is no standardized term to cover yields from 1 megaton upward. (See TNT equivalent.)
(USAEC-1974)
Yield (Y)
The total radiation emitted per unit time from an accelerator target as measured over the entire solid angle of 4p, divided by the beam current incident on the target.
(NCRP 51)
Note: References shown in ()