Hazard Evaluation - doe-std-3009-94_cn3

DOE-STD -3009-94

3.3.2.3

Hazard Evaluation

Hazard evaluation characterizes the identified hazards in the context of the

actual facility and process. For example, simple hazard identification would be

that 2000 grams of plutonium oxide are in a steel container under a hood

waiting for entry into a glove box. One accident, which places this hazard in

the actual context of facility parameters, involves spilling the container on the

room floor. The hazard evaluation would qualitatively consider the action of

moving the container into the glove box to evaluate the likelihood of spilling

the contents. It would also consider mitigative features that would affect

potential consequences. References such as Guidelines for Hazard Evaluation

Procedures (1992) provide acceptable guidelines for selecting hazard

evaluation techniques and generic lists of initiators that need to be incorporated

in systematic evaluation with a given technique.

Public and worker safety issues are the traditional focus of hazard evaluations.

The DSA hazard evaluation also examines the potential for large -scale

environmental contamination. The information on environmental

contamination may be used in a separate cost-benefit analysis, not related to

the DSA effort, to determine if additional preventive or mitigative features are

needed in the facility.

Tables 3-1 and 3-2 provide two examples of hazard analysis output. Table 3-1

is an example of a portion of the evaluation of a hydrogen fluoride unloading

operation. It identifies accident initiators, associated preventive and mitigative

functions, and operational safety enhancements determined to be necessary.

The parenthetical numbers in the table under the headings of "Cause,"

"Consequence," and "Frequency" distinguish a numbering system that serves

to identify specific accident scenarios (i.e., cause #1 is an event that has been

judged to have consequence #1 and frequency #1, resulting in the overall

ranking aligned with frequency #1). The ranking (i.e., low, medium, a nd high)

of estimated consequences and frequencies are based on judgment of analysts,

and the overall binning rank is in accordance with the numbers assigned to the

example in Figure 3-2. Table 3-1 demonstrates how a number of basic

accidents can be ident ified and evaluated in a concise manner. The last

column of Table 3-1 presents safety enhancements in the form of two

procedural verifications and two action items for procedural alteration that

were identified in the course of the evaluation.

Table 3-1 a lso provides an example of how worker safety issues are integrated

into this presentation. However, significant worker safety evaluations

unrelated to the hazard scope defined for a DSA (i.e., standard industrial

hazards) will be occurring outside the DSA. This reinforces the importance of

the emphasis in Section 3.3.1.1, "Hazard Identification," of identifying the

dividing line between process/activity hazards covered in the DSA and those

covered by direct OSHA regulatory compliance. Specifying the location of

this dividing line is essential to developing an integrated safety posture where

the functions of DSA hazard analysis vis--vis health and safety plans, job task

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