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.
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
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.