Source Te rm Analysis
This subsection determines the accidental material or energy released through
the pathways of concern. Define all parameters and phenomenological models
used to derive the source term. As a minimum, this definition includes the
material at risk (as derived from the hazard identification), the release fraction
or rate that determines the initial source term, and the overall facility leakpath
factors that determine the final source term released external to the facility.
The degree of conservat ism believed to be present in the calculation needs to
be consistent with the Evaluation Guideline definition. Detailed quantification
of uncertainty is not required.
This subsection determines the receptor doses associated with the relevant
pathways. Derive the doses in accordance with the definition of the Evaluation
The information derived from the hazard and accident analyses related to
protection of the public and potential insights gained for environmental
contamination issues needs to be compared to the facility National
Environmental Policy Act (NEPA) documentation to ensure that no significant
discrepancies exist between the DSA and that documentation.
Comparison to the Evaluation Guideline
This subsection compares the unmitigated receptor dose for the accident
sequence to the Evaluation Guideline. If the Evaluation Guideline is exceeded,
provide a summary assessment of the significance of the exceedance and
administrative and/or engineered controls whose implementation would
prevent or mitigate the accident sequence. Detailed cost-benefit analyses to
evaluate potential changes are beyond the scope of the DSA.
Summary of Safety-Class SSCs, SACs and TSR Controls
This subsection identifies the safety-class SSCs (or equivalent SAC) and
assumptions judged to require TSR coverage. Any TSR assumption not
directly related to exceeding of the Evaluation Guideline should be defined in
section 220.127.116.11.2, "Defense in Depth." For details, refer to Chapter 4, "Safety
Structures, Systems, and Components," and Chapter 5, "Derivation of
Technical Safety Requirements."