Interference from Radon - doe-hdbk-1113-98_reaffirm_2005

DOE-HDBK-1113-98

Radiological Safety Training for Uranium Facilities

Module 104 Internal Dose Control

The general method for personnel scanning for alpha contamination is

to scan at approximately 2 inches/ sec at a distance of approximately

inch. For personnel scanning for beta contamination, it is

recommended to scan at 2 inches/ sec at a distance of inch.

However, the surface being surveyed (i.e., soil, building surfaces,

equipment, personnel), the scanning speed, and the instrument

response time will determine the level of contamination that can be

detected.

Failing to survey properly can have the same results as not surveying

at all. Contamination may go undetected and may be tracked out of the

radiological area. Once outside the radiological area, the

contamination may be transferred from surface to surface. This

transfer of contamination could result in uranium ending up inside

your body, the body of a co-worker, or even the bodies of your family

members and friends. The potential for spreading undetected

contamination should always be kept in mind when performing self-

monitoring.

iv. Interference from Radon

One of the problems encountered when monitoring for contamination

is interference from radon and its decay products.

Radon is a radioactive gas that occurs naturally in the environment. It

decays by alpha emission in the first of a series of very short half-life

radionuclides that decay by alpha or beta-gamma emission.

There is a simple, inexpensive alternative to determine if the

contamination is due to radon. The effective half-life for radon