• Design deficiency applies to equipment or facilities found to perform their operating functions inadequately as a result of poor design.

  • Unexplained human error refers to human actions that were wrong for no reason recorded in the investigation reports or for which there is no apparent explanation. One example is when an operator assembled a piece of equipment incorrectly.

  • Mindset refers to the mental attitude people have about the process of disposal and the state of the system during processing. One example is when a person assumes an agent alarm is false because of a historical pattern of frequent false alarms.

  • Improper technique refers to a manner of performing tasks that causes either a hazard or a malfunction. An example is using equipment for purposes other than those dictated by design.

  • Failures of communication refer to failure to communicate essential information, failure to heed communicated information, and inadequate communications systems.

This committee requested an update on process-related chemical events from all operating sites and the two sites that completed destruction since the end of 2001. In all, 147 events were reported to the committee,3 of which 26 were reviewed by the chemical events committee in 2002. This committee evaluated the remaining 121 incidents for frequency of event type, process activity involved (e.g., maintenance, waste handling, weapons transfer, and agent transfer), consequence, and causal factors. The frequencies of incident types, activities, and causal factors mirror those that were noted in the 2002 Chemical Events Report. A summary of the causal factors for these 121 events is presented in Table 3-2.

“SOP deficiencies” was the most frequent causal factor, followed by “equipment malfunction” and “human error.” Significantly, almost all of the events were noted to have had multiple causal factors, as is evidenced by the fact that 215 causal factors were identified for 147 events (also see notes to tables).

The activities that had the most incidents and events were maintenance and waste handling. Thirty-one events happened during waste handling, including hydrolysate transfers and spills. Twenty-two events

TABLE 3-1 Frequency of Causal Factors in the 81 Chemical Events Reviewed by the Chemical Events Committee in 2002

Causal Factor

Number of Times a Causal Factor Was Identified

Percentage of Instances of Causal Factors

SOP deficiencies

30

29.4

Equipment malfunction

12

11.8

Human error

7

6.8

Design deficiency

16

15.7

Mindset

15

14.7

Improper technique

12

11.8

Failure of communication

10

9.8

 

102

100.0

NOTE: There is not a 1:1 correspondence between chemical events and instances of causal factors. Most events involved more than one causal factor, and for some events, it was not possible to determine causal factors.

TABLE 3-2 Frequency of Causal Factors in the 121 Events at Chemical Agent Disposal Facilities Since 2001

Causal Factor

Number of Time a Causal Factor Was Identified

Percentage of Instances of Causal Factors

SOP deficiencies

31

27.4

Equipment malfunction

29

25.7

Human error

29

25.7

Design deficiency

6

5.3

Mindset

6

5.3

Improper technique

7

6.2

Failure of communication

5

4.4

 

113

100.0

NOTE: There is not a 1:1 correspondence between chemical events and instances of causal factors. Most events involved more than one causal factor, and for some events, it was not possible to determine causal factors.

happened during maintenance activities. Only two incidents happened during munitions transfer and two during agent transfer; however, not all agent transfer incidents were tabulated. Twenty-five incidents occurred in the rocket shear machine, but the causes of 21 of these were not, or could not be, assigned.

In summary, it appears that the frequency, types, and causal factors of process safety events in chemical agent disposal facilities could not be correlated with the type of facility (neutralization or incineration), type of chemical weapon (blister agent or nerve agent), or how

3

Personal communication between Carl Anderson, ACWA, and James Myska, BAST Senior Research Associate, on July 20, 2010.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement