Inadequate control of chemical hazards cont'd - doe-hdbk-1139-1-2000

DOE-HDBK-1139/1-2000

Change Notice No. 1

Training. These events underscore the importance for chemical worker training to include hazard

information and lessons learned from accidents, previous studies, and similar events involving the same

chemicals and chemical work practices

A chemical tank explosion caused significant localized damage to a facility. Personnel failed to

recognize the phenomenon that was being created inside the tank. Concentration by evaporation of a

dilute solution of hydroxylamine nitrate and nitric acid occurred to the point where an autocatalytic

reaction created a rapid gas evolution that over-pressurized the tank beyond its physical design

limitations. Similar hazards were identified as early as 1970, and reports of various accidents were

available to the facility. However, these hazards were not included in training and qualification

programs to heighten awareness of the chemical hazards. (ORPS Report RL--PHMC-PFP-1997-

0023, Final Report 05-17-99)

An explosion occurred when a chemical operator performing lithium hydride recovery operations

submerged a high-efficiency particulate air (HEPA) filter embedded with lithium hydride residue into

a salvage vat containing demineralized water. Lithium hydride reacts exothermically with water to

form caustic lithium hydroxide and flammable hydrogen gas. The exothermic reaction produced

enough heat to begin burning the filter's wood framing, even though the filter was submerged.

Investigators believe that oxygen from air trapped in the filter combined with the hydrogen generated

from the reaction caused the explosion. Investigators also determined that it had once been a skill-of-

the-craft practice to perforate a filter with holes before cleaning to more efficiently liberate entrapped

air and hydrogen during the reaction. This past practice had been lost over time, owing to the attrition

of experienced operators, and had not been captured in the procedure for cleaning the filters. (ORPS

Report ORO--LMES-Y12NUCLEAR-1999-0031)

A high-pressure carbon dioxide (CO2) fire suppression system unexpectedly actuated, resulting in

one fatality, several life-threatening injuries, and significant risk to the safety of the initial rescuers.

Investigators determined the inadvertent operation of electric control heads released CO2 into the

occupied space without a discharge warning alarm. In addition, the CO2 system was not physically

locked out as was required. The procedure that required this barrier had not been updated or used for

this work. The requirement to train workers in the hazards of emergency response to CO2 discharges

had not been incorporated into training programs. A contributing cause for the accident was the

failure to take corrective actions and apply lessons learned from previous accident investigations,

particularly in work planning and control. (ORPS Report ID--LITC-TRA-1998-0010)

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