Distinguishing Types of Design Requirements

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unnecessary requests for engineering evaluations from the operations and maintenance organizations

(e.g., if the pump loses its ability to pass a surveillance test for 250 gpm). If, on the other hand, the

designer had decided to specify an oversized pump, the design requirement would be 250 gpm and the

design basis would reflect the rationale for the requirement. Appendix II-B provides further examples of

design requirements and design basis.

Distinguishing Types of Design Requirements. Distinguishing among the various types of design

requirements is beneficial, not only for establishing, documenting, and maintaining the design

requirements and associated design basis, but also for evaluating changes. Changes to safety design

requirements generally involve unreviewed safety questions (USQ) evaluations and more significant

reviews and approvals. Other design requirement changes may be readily accepted from a safety

viewpoint. Further, certain CM functions and activities may be implemented on a graded approach.

Distinguishing among the design requirement types is necessary to apply graded approach options.

SSC grading is also necessary and useful for other facility programs, including the maintenance

program, the QA program, the SAR upgrade program, etc.

Some design requirements do not relate directly to safety, environment, or mission. For example, the

designer might specify a design requirement for ease of operations, maintenance, or testing, or based

on equipment availability. Specifically, a centrifugal pump might be available and specified, while a

positive displacement pump could also have been acceptable. These design requirements cease to be

optional after the design process is complete. They were optional to the design engineer, but once

established, they are design requirements that need to be translated into the physical configuration and

facility documentation. The ability to control overall configuration depends on identifying and including

the full set of design requirements, particularly for important systems.

As an example of the importance of categorizing design requirements, suppose the pump installation

specification from design engineering states that a minimum of 4 feet of free space needs to be

provided around the pump. This requirement might have emerged from a maintenance consideration,

in which case it is not directly related to safety, environment or mission. The documented basis for this

design requirement might have been a simple notation in the design package. Alternatively, the pump

might need free space to dissipate worst-case heat loads to achieve its safety function. In this case, the

design requirement would be a safety design requirement and a heat-load calculation would be

expected as part of the design basis information for the pump. Knowledge of the design requirement

type and its basis is needed to evaluate proposed design or operational changes.

I-B.3 DOCUMENT CONTROL ELEMENT

A CM program does not encompass the entire scope and functions of an overall facility or site

document control program. The scope of an overall document control program might be larger than

the CM program's document control element; it might include administrative records and information on

equipment outside the CM program scope. A CM program deals with that subset of information

necessary for adequate configuration management. A CM program provides input to the overall

program by defining those special document control activities needed to support an effective CM

program. However, it should not absorb the functions of an overall document control program.

Individual facilities will have to decide the best method to integrate CM document control criteria into

their existing program for document control. In contrast to traditional document control programs for

satisfying QA requirements, the CM program document control element emphasizes the technical

content of the documents and the needs of the document users. It includes provisions for document

ownership by technical organizations, tools to support document identification and retrieval, timely

distribution of document changes, tracking of pending document changes, and timely retrieval of

requested documents.

I-B-7