Scenario of events cont'd - DOE-HDBK-1141-2001

Radiological Assessor Training

DOE-HDBK-1141-2001

Instructor's Guide

This same employee was also known to be

contaminated at the C-337 building exit on two

separate monitors (twice on one, once on the other)

when leaving after the shift change approximately

0700 on August 23, 1991. The employee stated that

the first monitor alarmed, but that the second

monitor did not indicate the contamination.

No monitoring data was found for the second

employee, since he did not utilize equipment

capable of storing this information.

Personal egress monitoring data from the facility

was also reviewed, and individuals from prior shifts

were contacted and monitored. An operator who

was in the C-337-A area extensively from 0700 to

1830 hours on August 22, 1991, had a new pair of

company-issued shoes, which were found to be free

of contamination. This operator had left the C-337-A

facility at 1830 hours on August 22, 1991.

Additionally, routine surveys on August 19, 1991, did

not indicate a similar contamination problem. Since

no significant contamination problems were

identified prior to 1900 hours on August 22, 1991,

the investigation focused on the activities from 1900

hours on August 22, 1991, to 0700 hours on August

23, 1991.

Urinalysis, as well as in vivo internal dosimetry

assessments, was performed on these employees

and did not indicate any evidence of internal

contamination. Personnel whole-body external

radiation dosimeters worn by both employees,

although externally contaminated, did not indicate

that abnormal doses to ionizing radiation were

received.

Skin dose calculations showed less than 0.10 rem

for Employee No. 2 and 1.50 rem for Employee

No. 1, compared to an annual limit of 50 rem.

Module 16 9