Discussion cont'd - s1036cn10018

DOE-STD-1036-93

If a verifier watches an operator read from a procedure, check the component label,

operate the component, and then mark the item off in the procedure, it would be

natural for the verifier to assume that the operation was performed correctly.

However, the operator could have misread the procedure, misread the label,

incorrectly identified the equipment, or performed the wrong operation. If the

verifier is not present during the operation (separated by distance) and performs the

verification at a later time, then the verification will not be affected by the operator's

actions. If the verifier walks through the procedure, personally checking the label

information and verifying the position of the components, any mistake made by the

operator is likely to be detected.

For some operating activities, separating the operation and the verification by time and

distance may not be possible. For example, verifying the position of a throttle valve or other

control may require observation of the positioning activity. Verification for the installation or

removal of jumpers may require checking the intended action before it is performed, because

incorrect performance could cause a shutdown of critical equipment or actuation of a safety

system. For these types of operating activities, the operator and verifier should

independently identify the component and then concur on the action to be performed. The

verifier should observe that the operation is performed correctly. This method is termed

"concurrent dual verification."

Independent verification will be most effective if it is incorporated into existing operating

activities. Each facility's operating guidelines should identify the specific systems, structures,

and components that require independent verification. Within those systems, structures, and

components, the guidelines should identify the occasions when independent verification

should be performed. Facility procedures should provide instructions for the independent

verification techniques appropriate to specific systems and components. These instructions

are necessary to ensure that verification is performed consistently, and that verification

activities do not change the component status or upset the process. Independent verification

requirements should be addressed in pre-job briefings, to identify the personnel involved and

to clarify the methods that will be used. Facility training programs should include subjects