Defense in Depth - doe-hdbk-1188-20060024

DOE-HDBK-1188-2006

proposals, procurement specifications, design specifications, testing requirements, contracts, or

the like. It also includes those items, materials, or services found, during acceptance testing,

preoperational testing, operations, inspections, or audit, not to meet the quality or reliability

requirements appropriate to the use or specificity of the item or service procured. It also

includes misrepresentation of the specifications or trademarks associated with the parts/service

which fail or are otherwise found to be inadequate because of random failures or errors within

the accepted reliability level. [DOE M 232.1-1A]

130.

DEFENSE IN DEPTH. An approach to facility safety that builds-in layers of defense against

release of hazardous materials so that no one layer by itself, no matter how good, is completely

relied upon. To compensate for potential human and mechanical failures, defense in depth is

based on several layers of protection with successive barriers to prevent the release of

hazardous material to the environment. This approach includes protection of the barriers to

avert damage to the plant and to the barriers themselves. It includes further measures to protect

the public, workers, and the environment from harm in case these barriers are not fully effective.

[DOE G 450.4-1B]

131.

DEFERRED MAINTENANCE. Maintenance that was not performed when it should have

been or was scheduled to be and which, therefore, is put off or delayed for a future period and

reported annually. [DOE G 433.1-1]

132.

DEFICIENCY. Any condition that deviates from the designed-in capacity of structures,

systems, and components and results in a degraded ability to accomplish its intended function.

[DOE G 433.1-1]

133.

DEFICIENCY TAG/STICKER. A small tag or adhesive-backed sticker that is used to

identify a facility material deficiency. The form may be marked with a serialized number for

administrative control, work order identification, and deficiency location by maintenance

personnel. [DOE G 433.1-1]

134.

DEFLAGRATION. A rapid chemical reaction in which the output of heat is sufficient to enable

the reaction to proceed and be accelerated without input of heat from another source.

Deflagration is a surface phenomenon, with the reaction products flowing away from the

unreacted material along the surface at subsonic velocity. The effect of a true deflagration under

confinement is an explosion. Confinement of the reaction increases pressure, rate of reaction

and temperature, and may cause transition into a detonation. [DOE M 440.1-1]

135.

DEPARTMENT means the United States Department of Energy or any predecessor agency.

[10 CFR 820.2]