Implementation and Maintenance of SACs

DOE-STD-1186-2004

will need to be performed to substantiate the available time interval necessary to accomplish

the task. Consequences of incorrect implementation of the control should be evaluated and

measures to prevent control failure should be factored into the control formulation.

If SACs require operator action and perform a function similar to a SC SSC, a human

reliability assessment (HRA) should be performed as part of the Specific AC formulation.

The HRA validates the dependability of an SAC and can identify weaknesses in the

proposed procedures to implement an SAC and suggest additional measures to improve the

overall dependability.

Verification: SACs implemented by TSRs must be initially (prior to operation) and

periodically verified to perform their intended safety function. In the context of SACs, this

may involve "dry runs," procedure walk-downs, tabletop exercises, or actual hazard/casualty

exercises. Additionally, the verification process should be performed by knowledgeable

individuals who were not part of the formulation of the control to assure an unbiased

assessment of the effectiveness of the control. In addition, the control should be formulated

so that it is easily and readily verifiable through appropriate and ongoing testing,

examination or surveillance activities. Periodic re-verification that SACs are performing, or

capable of performing, their intended safety function should be addressed through Limiting

Conditions for Operation (LCO) Surveillance Requirements (SR) for SACs written as LCOs,

or through facility operations and maintenance procedures if the Specific AC is incorporated

into the AC section of the TSRs.

2.3

Implementation and Maintenance of SACs

SACs are generally procedures. These procedures should include specifications for

implementation such as qualifications of involved personnel, steps involved, verification of

identified limits, frequency of verification, requirements for any independent verifications,

interfaces with measuring equipment, and the required accuracy of the equipment, etc. TSRs

are the formal requirements that implement those procedures and recovery actions in the case

of breakdown of the control. SACs are addressed through the TSRs generally by two forms as

identified below.

a. LCO/Surveillance Requirement