Special controls and considerations at uranium operations cont'd

Radiological Assessor Training

DOE-HDBK-1141-2001

Student's Guide

C. Uranium metal in finely divided form is

pyrophoric; therefore, any grinding or milling

operations must be carefully conducted to avoid

fires.

Uranium hexafluoride is commonly found in many

uranium operations. This material is a solid at

room temperatures but volatilizes readily at

elevated temperatures. As a gas, it is extremely

hazardous, forming hydrofluoric acid when it

comes in contact with water. Operations

involving uranium hexafluoride must be

conducted very carefully to prevent release of the

gas.

D. External radiation hazards from uranium are

primarily associated with decay products;

therefore, operations in which the decay products

can separate and concentrate must be monitored

carefully. For example, crucibles used to melt

depleted uranium and casks used to ship

uranium hexafluoride are sometimes more

radioactive after they are emptied than when they

are full. The reason is that the decay products

are left in the emptying process and are no longer

self-shielded by the uranium.

Module 6 - 10