Carbon-14 (C-14) - doe-hdbk-1106-97

DOE-HDBK-1106-97

Instructor's Notes

CARBON-14 (C-14)

Carbon-14 is a low-energy beta emitter (about 10 times more

energetic than tritium). C-14 is not easily detected with a

handheld survey instrument such as a thin-window G-M (the

efficiency is ~ 10%). Monitoring is normally performed by

taking a swipe of the area and counting the swipe in a liquid

scintillation counter.

1. Maximum energy: 0.156 MeV (the average energy is

0.052 MeV).

2. Maximum range in air: 9 inches (24 cm).

3. IAEA toxicity classification: Medium-low.

4. Physical half-life: 5,730 years.

5. Effective half-life: (Teff): 12 days.

6. Critical organ: Whole body and the body fat.

7. Personnel monitoring: Bioassay - urinalysis and/or breath

measurements (CO2), NOT detected with a dosimeter

(TLD or film).

8. ALI:

2 mCi (7 x 107 Bq) -labeled organic compounds by

inhalation or ingestion.

2 Ci (7 x 1010 Bq) CO by inhalation.

200 mCi (7 x 109 Bq) CO2 by inhalation.