Derived Concentration Guide (DCG)

DOE-HDBK-XXXX-2005

06/30/2005

air breathed by an average worker for a working year of 2000 hours (assuming a

breathing volume of 2400 m3 ). For the radionuclides listed in appendix C of 10 CFR

835, the air immersion DACs were calculated for a continuous, non-shielded exposure

via immersion in a semi-infinite atmospheric cloud. The value is based upon the derived

airborne concentration found in Table 1 of the U.S. Environmental Protection Agency's

Federal Guidance Report No. 11, Limiting Values of Radionuclide Intake and Air

Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion,

published September 1988. This document is available from the National Technical

Information Service, Springfield, VA. [10 CFR 835.2]

136.

DERIVED CONCENTRATION GUIDE (DCG). The concentration of a radionuclide in

air or water that, under conditions of continuous exposure for one year by one exposure

mode (i.e., ingestion of water, submersion in air, or inhalation) would result in an

effective dose equivalent of 100 mrem or 0.1 rem (1 mSv). DCGs do not consider decay

products when the parent radionuclide is the cause of the exposure (DCG values are

presented in Chapter III of DOE O 5400.5 Chg 2). (1 rem = 0.01 sievert) [DOE O 5400.5

Chg 2]

DESIGN BASIS. The design inputs, the design constraints, and the design analysis and

137.

calculations. It includes topical areas such as seismic qualification, fire protection, and

safe shutdown. It encompasses consideration of such factors as plant availability, plant

efficiency, costs, and maintainability, and that subset that relates to safety and the

authorization basis. [EH62dd1]

138.

DESIGN BASIS. The set of requirements that bound the design of systems, structures,

and components within the facility. These design requirements include consideration of

safety, plant availability, efficiency, reliability, and maintainability. Some aspects of the

design basis are important of safety, although others are not. [DOE O 5480.23]

DESIGN BASIS ACCIDENTS. Those postulated accidents that establish design and

139.

performance requirements for systems, structures, and components important to safety.

[EH62dd1]

140.

DESIGN BASIS ACCIDENTS (DBAs). Accidents that are postulated for the purpose of

establishing functional requirements for safety significant structures, systems,

components, and equipment. [DOE O 5480.23]

141.

DESIGN BASIS EARTHQUAKE (DBE) (equivalent to safe shutdown earthquake). An

earthquake that is the most severe design basis accident of this type and that produces the

vibratory ground motion for which safety class items are designed to remain functional.

[DOE O 6430.1A]

DRAFT