System Design Descriptions

DOESTD107393

Inaccurate design requirements and design basis can be identified by discovering conflicting

documentation, a conflicting physical configuration, or errors (in calculation, for example) in the design

basis. To assess accuracy, the management review could employ some combination of the following

methods:

Checks of reasonableness by competent design personnel

Checks to determine whether the design requirements apply to current physical configuration

Reperformance of critical calculations and analysis independently or with different methods

The facility design requirements should be documented in a retrievable, user-friendly manner. The

relevant design information should be identified by system and an index of design documents should be

provided. To determine whether the design is fully documented, the management review should

consider whether: the design information is clearly identified; the design requirements are differentiated

from the design basis; safety, environmental, and mission design requirements are differentiated from

other types of design requirements; and the design documentation is indexed, integrated, and usable.

Objectives for the documentation of design information are provided in Chapter 3.

If design reconstitution is warranted, the management review should develop recommendations as to the

extent of design reconstitution needed and the associated priority.

2.2.1.4 System Design Descriptions

The CM program and engineering management may decide to prepare system design descriptions

(SDDs) to collect and summarize existing design requirements for each system and topical area. The

SDDs would help facility personnel understand system functions and requirements. They would include

system drawings and a system description, as well as descriptions of functional process requirements,

system and component design requirements, system interfaces and interlocks, setpoints, and design

requirements related to operations, maintenance, and testing. The SDDs could be predecessors of the

design information summaries (DISs) prepared by the DR adjunct program. They should be prepared in

a format convenient for adoption into the DISs that will be developed later. DOE Standard NE F 1-2T,

Preparation of Plant and System Design Description Documents, provides information on documenting

design requirements.

2.2.1.5 Configuration Management Equipment Database

The CM equipment database should be established to cross-reference the CM program SSCs with their

design requirements, design basis, and associated documents. This database is the primary information

source for design requirements. It should use the Best Available Design Information to fill the database

fields. This Best Available Design Information comes from three basic sources: (1) existing design

information, (2) new or revised design information, and (3) reconstituted design information.

Computer databases can effectively and efficiently support the design requirements element, serve many

users, and advance configuration management. Computer database development should maintain focus

on achieving the associated CM program elements and functions. The program management element

provides general direction, including general contents, for CM databases. Given the extent of the

contents, relational databases will likely be most effective, as they can relate records in one file to records

in many other files. For example, the equipment database should be able to identify the SSCs involved in

the fire protection program.

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