Accident Analysis - DOE-STD-1120-1-20050034

DOE-STD-1120-2005/Vol. 1

Exhumation (digging) operations could introduce dispersible energy for buried wastes or soil

Combustible fluids from operating equipment in proximity to exposed wastes, as well as fire

hazards from equipment itself, could introduce fire hazards.

Packaging, repackaging, overpacking and waste staging/stacking could create potential for

spills, accumulation/concentration of reactive materials or hazardous substances, waste or

constituents, or re-distribution of fissile materials.

Movement/loading of waste materials introduces potential for vehicle accidents.

Inventories or high energy sources added by the restoration activity (e.g., any process

chemicals, packing or fill material, or quantities of combustibles).

4.2.3

Accident Analysis

The vast majority of environmental restoration projects are not expected to require detailed

analysis and quantification of accidents given the expected magnitude of radionuclide inventory

and associated consequences (i.e., well below the EG). However, for HC2 facilities that have

potential scenarios with consequences that could challenge or exceed the EG, the accident

analysis needs to present explicit calculations for both the source term and consequences

sections (i.e., in accordance with sections 3.4.2.X.2 and 3.4.2.X.3, using DOE-STD-3009 safe

harbor format). Unmitigated source terms and consequences should also be considered for

points in time in which anticipated step-out conditions will apply. These step-out conditions

could be decreased hazardous materials inventories and/or changes in material forms that are

likely to be present during the restoration activity. This can then serve as the bases for the

change in safety control designation or elimination of controls.

4.3

Hazard Controls

As described in 10 CFR 830.205(c), TSRs are not required for environmental restoration

projects2, which are subject to the provisions of HAZWOPER. This is consistent with the

philosophy that environmental restoration activities are typically not expected to involve hazards

that will necessitate active safety SSCs and associated TSRs. Although TSRs are not required,

general requirements described in 10 CFR 830.204(b)(4) must still be met. This requires that

hazard controls be derived, that adequacy of controls be demonstrated and that a process be

defined for maintaining hazard controls current. Therefore, the focus of the "hazards control"

section of the DSA should be on the essential SSCs and administrative controls that prevent or

mitigate a release of radionuclides or hazardous chemicals. Safety management programs that

are generally relied on for worker protection should also be presented.

TSRs and associated derivation within the DSA should be considered for the unlikely case where environmental

restoration projects require active SSCs to provide for significant worker safety or protection of the public.

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