Considerations In Developing a Material at Risk (MAR) TSR Control:

DOE-STD-1186-2004

Specific AC is well defined, clear corrective actions are available, and conditions supporting the

Specific AC can be easily surveilled. An example of this type of format is shown in Example 1.

Guidance for developing and writing LCOs is provided in DOE G 423.1-1. Although this

guidance is directed at LCOs used to support Safety SSCs, an SAC has a safety function with

importance similar to, or the same as, the safety function of safety class or safety significant

SSCs. As such, the guidance given in this section can be directly applicable to SACs written as

LCOs. SACs written as LCOs should generally comply with the guidance given in

DOE G 423.1-1 for LCOs including, but not limited to, Specification for Limiting Conditions for

Operation, Action Statements, Operability, Surveillance Requirements, Violation of Technical

Safety Requirements, and TSR Bases.

The second method available to incorporate SACs in a TSR document is to identify the specific

requirement/action in a special section in the Administrative Control section of the TSR. This

format may be appropriate when it is essential that the Specific AC be performed when called

upon every time and without any delay (e.g., hoisting limits for nuclear explosives, MAR limits,

or expected responses during criticality safety infractions not covered by an LCO) or when

definitive program requirements for specific activities can be stated. An example of this type of

format is shown in Example 2 of this section.

4.3

Considerations In Developing a Material at Risk (MAR) TSR Control:

MAR is the major analytic assumption that must be made before a hazard analysis can support

any consequence binning beyond the purely subjective and before any non-qualitative accident

analysis can be initiated. Further, MAR assumption violations place the facility in a formally

unanalyzed space for which consequences would be unknown and potentially unbounded. It is

essential that MAR assumptions be protected in a highly reliable and enforceable manner.

However, it is not normally possible to control MAR with an active or passive SSC. Under

normal circumstances, MAR cannot be controlled through a Design Feature or SSC based LCO.

This leaves only administrative-type controls in the form of a TSR Section 3 / 4 (Operating

Limits and Surveillance Requirements) LCO (in itself a type of Administrative Control) for MAR

or a TSR Section 5 AC (Programmatic AC or Specific AC).

Use of an LCO is warranted when a defensible estimate can be made of how much of a MAR

limit can be exceeded. Provided this estimate can be made, it may be possible to make an