Safety Basis Analysis - doe-std-1128-98

DOE-STD-1128-98

C.2.3

Safety Basis Analysis

A contractor who is responsible for the design, construction, or operation of DOE

nuclear facilities, as designated in writing by the Program Secretarial Officer, is

required to perform a safety analysis. The safety analysis shall evaluate the

adequacy of the safety basis for each facility. Safety basis is defined as the

combination of information relating to the control of hazards at a nuclear facility

(including design, engineering analyses, and administrative controls) upon which

DOE depends for its conclusion that activities at the facility can be conducted

safely. The level of safety analysis to be performed must be commensurate with the

magnitude of the hazards being addressed, the complexity of the facility and/or

systems being relied upon to maintain an acceptable level of risk, and the stage of

the facility life cycle. The safety analysis report (SAR) defines the safety basis,

document the logic of its derivation, demonstrate adherence to the safety basis, and

justify its adequacy. Included in this process is evaluation of the design features

and their contribution and/or mitigation to the safety basis. The SAR and the

analyses performed describes the design basis accidents considered, the risk-

dominated accident scenarios that have been analyzed, and the measures taken to

eliminate, control, or mitigate the consequences. The design elements discussed in

DOE Order 420.1a, Facility Safety (DOE, 2002a), shall also be considered.

Structural design including loading combinations and construction of critical items

should, as a minimum, be in accordance with current editions of pertinent

nationally recognized codes and standards. All other facility design features shall

conform to applicable criteria and to other site- or process-specific criteria

developed for the facility.

C.3 STRUCTURAL CRITERIA

The structure and its associated critical equipment and the ventilation, electrical, fire

protection, and utility systems shall be designed to limit the release of radioactive materials

during design-basis accidents postulated for the facility.

The structural design, the load combinations, and the construction of critical safety and fire

protection features should be in accordance with the latest edition of applicable nationally

recognized codes. When local codes or regulations are more stringent than the nationally

recognized codes, the local codes should be followed.

C.3.1

Tornado Resistance

Critical operating areas of the facility should be designed to withstand the design-

basis tornado. Specific information on site-specific tornado hazard curves,

rotational speeds, elastic or plastic design methods, and other design criteria are

provided in UCRL-53526 (Coats, 1984).

If site-specific hazard model studies are not available, a hazard model should be

developed that is consistent with the approach used in UCRL-53526 (Coats, 1984).

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