Regeneration of Missing Critical Design Information

DOESTD107393

and expertise. Operability and reportability reviews should be performed according to standard

procedures.

Underlying all DR program activities is the presumption of system and component operability unless,

and until, there is confirmed information to the contrary. The presumption of operability is reasonable

where broad engineering experience and judgment indicate that an affected system or component is

functional, even if sufficient information is not available to make and fully document the final decision on

a particular discrepancy. Under the presumption of operability, the information necessary to make a

clear determination should be obtained or developed expeditiously and should be acted on thereafter.

This approach satisfies the need to operate facilities conservatively by limiting the potential for

unnecessary challenges to facility safety systems and personnel. The presumption of operability is not

intended as a means of deferring actions necessary to address discrepancies; if a discrepancy clearly

affects the safety of facility operation, action to place the facility In a safe condition has to be taken.

Each open item is evaluated and disposed of within the DR program in a manner that supports the

program deliverables and schedule. The order of resolution should be based on importance and

potential impact. The discrepancy resolution program should track each open item and discrepancy

through to completion and closeout. Resolution of open items and discrepancies includes

documenting the final disposition. Items directed to existing issue management programs should be

tracked to ensure that resolution is complete.

3.5 REGENERATION OF MISSING CRITICAL DESIGN INFORMATION

The technical management review determines what design information is missing and which items of

missing information will be regenerated. Missing information that is critical to design or operation

should be regenerated. The order of regeneration activities should be based on their importance.

Regeneration of the design requirements should begin before regeneration of the design basis to

provide a complete and accurate set of design requirements as promptly as possible. Regeneration of

design requirements is a high priority because the physical configuration is established by, and should

be consistent with, the requirements. The processes for design requirements and design basis

regeneration should be similar.

Regeneration of design requirements may begin after the evaluation of design requirements and

proceed in parallel with the completion of the comprehensive search. Regeneration of design basis

information should be initiated after the comprehensive search and the evaluation of design basis

information to identify missing information. Design basis regeneration is not needed for initial DIS

issuance, but it may occur in parallel with the preparation of the initial DISs.

3.5.1 REGENERATION OF DESIGN REQUIREMENTS

The missing design requirements may include requirements of each type (e.g., safety, environmental,

mission) for SSCs of each grade (e.g., safety, environmental, mission). If missing design requirements

were fully regenerated, each type of requirement for each grade of SSC would be regenerated. Full

regeneration of design requirements may be appropriate for the most important grades of SSCs (such

as safety and environmental), but not for every SSC.

Facilities should consider the missing design requirements for a given system or topic, determine which

requirements are critical, and prioritize the associated regeneration activities. Regeneration of design

requirements for SSCs that support the accident analyses or TSRs should receive highest priority.

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