DISs would typically include these general sections:
Introduction. Provide overall document format and content. Describe intended purpose,
uses, and users of document. Briefly describe DR process. Describe maintenance and
control of document. Reference DIS User's Guide.
Open Items. DISs might be issued without full resolution of open items and discrepancies
identified during the information retrieval, evaluation, and validation. Provide a list of open
items from the DR process, such as document conflicts, missing or inadequate
documentation, unresolved issues of a specific or generic nature, and discrepancies found
during field validation. State the process and schedule to complete resolution of any open
items. Include a categorization or prioritization of items, if established. Periodically update
open item lists until resolution is complete. This list is typically provided in an appendix or
toward the back of the document.
References. A list of the documents containing design basis information. These include
calculations, analyses, engineering evaluations, correspondence, topical reports, vendor
reports and evaluations, engineering safety evaluations, and other data.
Tables/Figures/Appendices. Tables and figures may be utilized to list data. Tables and
figures should be referenced to the appropriate section. Appendices or attachments may
include detailed information that is not in the main body of the DIS.
Miscellaneous. DISs typically include Cover Sheet, List of Effective Pages, Table of Contents,
List of Figures, List of Tables, and other administrative pages or sections.
The primary benefits are derived from the actual reconstitution of the design requirements and design
basis, rather than from formatting this information into DISs. Once the design information is
reconstituted, it is made available through the CM equipment database. However, for facilities with
limited databases, DISs serve as the primary source of equipment information.
The greatest benefit of an effective design reconstitution program may be the avoidance of facility
downtime (i.e., major shutdown for design basis reconstitution). The ability to identify and use existing
design margins when problems arise is also important. DISs provide valuable design input information
readily accessible for evaluation of future changes and facility modifications.
The importance of design basis lies in the evaluation of changes -- either previous changes or proposed
changes -- including the evaluation of system/equipment degradation. If a change is not being
evaluated or if the design requirements are valid and known, the need to understand the design basis
would be minimal. In these instances the design basis could be developed in conjunction with proposed
changes or the evaluation of changes that impact the design requirements. However, if a prospective
design change would also involve the redevelopment of extensive design information for the facility
system involved, the cost of making that particular change might become prohibitive and, accordingly,
the consequence could be the inability to make needed facility improvements.