Units of radiation

Becquerel: the derived SI unit of radioactivity equal to one disintegration per second. Symbol: Bq [named after A. H. BECQUEREL]

Curie: a unit of radioactivity equal to 3.7 X 10¹⁰ disintegrations per second. Symbol: Ci [ named after Pierre CURIE ]

Quantity of radiation exposure, which has a definite adverse effect, as destroying or ionizing cells, is called radiation dose.

There’re two principally different doses: exposure dose and absorbed dose.

Exposure dose unit is Roentgen: a unit of dose of electromagnetic radiation equal to the dose that will produce in air a charge of 0.258 X 10-3 coulomb on all ions of one sign, when all the electrons of both signs liberated in a volume of air of mass one kilogram are stopped completely. Symbol: R.

Gray: the derived SI unit of absorbed ionizing radiation dose or kerma equivalent to an absorption per unit mass of one joule per kilogram of irradiated material. Symbol: Gy 1 gray is equivalent to 100 rad.

Dose equivalent: a quantity that expresses the probability that exposure to ionizing radiation will cause biological effects. It is usually obtained by multiplying the dose by the quality factor of the radiation, but other factors may be considered. It is measured in sievert (SI unit) or rem.

Chapter 3: RISK MANAGEMENT

SAFETY TERMS

HAZARD in relation to a person is defined as "anything that may result in injury to a person or harm to the health of a person".

ACCIDENT: unplanned event or happening with the undesirable outcome.

(Fatigue; Illness; Injury)

RISK: The possibility of an unwanted event occurring.

Statistically risk is defined as ratio: R=accidents*1000(people)/people (workers) for some period; year.

Problem: find risk if known 10 shocks per 10000 workers within a year.

Axiom: all activities are potentially risky.

Safety provides conditions free from risk only with some probability.