Planned Design and Operational Safety Improvements

DOE-STD -3009-94

3.3.2.3.1

Planned Design and Operational Safety Improvements

If the DSA preparer wants to make commitments to planned improve ments not

yet implemented (as a result of the hazard evaluation), this section will identify

those major design and operational improvements. Summarize the basis for

committing to the improvement and, if needed, any interim controls proposed

until the improvement is implemented. Provide a general outline of the

improvement intended to the degree it has been conceptually finalized. Due to

capital costs, need for further study (e.g., technical issues, cost benefit),

procurement lead times, or other complications, it may not be feasible to

implement such design or operational improvements prior to DSA submittal.

DOE does not desire to unduly delay DSA completion for such items, and

numerous safety precedents acknowledge accepting work in progress.

Accordingly, the facility operator may choose to commit to implementation of

an improvement that is not reflected in current design or facility operations.

3.3.2.3.2

Defense in Depth

This section summarizes significant aspects of defense in depth, and identifies

associated safety-significant SSCs, SACs and other items needing TSR

coverage. Include both the facility design and administrative features of

defense in depth.

Facility design germane to defense in depth typically includes SSCs that

function as:

Barriers to contain uncontrolled hazardous material or energy release

(e.g., metal dissolver vessel).

Preventive systems to protect those barriers (e.g., hydrogen detection,

air purge, and shutdown systems for metal dissolver).

Systems to mitigate uncontrolled hazardous material or energy

release upon barrier failure (e.g., ventilation zone confinement).

Administrative features are typically linked to the overall safety management

programs that directly control operations. Administrative features include the

following aspects of operator interfaces:

Procedural restrictions or limits imposed.

Manual monitoring of critical parameters.

Equipment support functions.

Responses or actions counted on to limit abnormal conditions,

accident progression, or potential personnel exposure.

Page 38