Hand contamination of radiation workers

Three operators were contaminated during the transfer of a Mo-99 inner container from the packaging hot cell to the helium leak test station inside the facility. The inner container was loaded with Mo-99 product in a bottle.

The outer surface of the inner container was cross contaminated with Mo-99 by the manipulator jaws which were used to replace the lid on the inner container after the manipulator jaws accidently touched the Molybdenum Product Bottle (MPB) inside the packaging hot cell.

During the required wipe tests of the inner container outside the hot cell, the hands of three operators were contaminated.

Shortly after the incident the doses to the operators were preliminarily determined by establishing the exposure model using the CCTV records, Health Physicist Surveyor (HPS) measurements and the waste recovered as evidence material. The further investigation best estimated equivalent doses to skin of the hands were as follows.

Operator 1: 377 mSv
Operator 2:732 mSv
Operator 3: 1444 mSv

The annual dose limit for extremities and skin is 500 mSv according to the relevant legislation.

Location: Sydney, ANM Facility, ANSTO Lucas Heights
Event date: Fri, 21-06-2019
Nuclear event report
Legenda & explanation