Evaluation of Existing Facilities

DOE-STD-1020-2002

is slightly more severe than that corresponding to the design criteria for essential facilities (e.g.,

hospitals, fire and police stations, centers for emergency operations) in accordance with model

building codes (e.g., Ref. B-7).

Performance Category 3 and higher SSCs pose a potential hazard to workers, public

safety and the environment because radioactive or hazardous materials are present. Design

considerations for these categories are to limit SSC damage so that hazardous materials can be

controlled and confined, occupants are protected, and functioning of the SSC is not interrupted.

The performance goal for Performance Category 3 and higher SSCs is to limit damage such that

DOE safety policy is achieved. For these categories, damage must typically be limited in

confinement barriers (e.g., buildings, glove boxes, storage cannisters, vaults), ventilation systems

and filtering, and monitoring and control equipment in the event of an occurrence of severe

earthquakes, winds, or floods. In addition, SSCs can be placed in Performance Categories 3 or 4

if improved performance is needed due to high hazard material confinement, danger of criticality

(Reference DOE G 420.1-2) and cost or mission requirements. For Performance Category 3

SSCs, an appropriate performance goal has been set at an annual probability of exceedance of

about 10-4 of damage beyond which hazardous material confinement and safety-related functions

are impaired.

For Performance Category 4 SSCs, a reasonable performance goal is an annual probability of

exceedance of about 10-5 of damage beyond which hazardous material confinement and

safety-related functions are impaired. These performance goals approaches and approximates,

respectively, at least for earthquake considerations, the performance goal for seismic-induced

core damage associated with design of commercial nuclear power plants (Refs. B-14, B-15,

B-16, and B-17). Annual frequencies of seismic core damage from published probabilistic risk

assessments (PRA) of recent commercial nuclear plants have been summarized in Reference

B-18. This report indicates that mean seismic core damage frequencies ranged from 4x10-6/year

to 1x10-4/year based on consideration of 12 plants. For 10 of the 12 plants, the annual seismic

core damage frequency was greater than 1x10-5. Hence, the Performance Category 4

performance goals given in the NPH Guide for DOE O 420.1 are consistent with Reference

B-18 information.

B-3

Evaluation of Existing Facilities

New SSCs can be designed by these criteria, but existing SSCs may not meet these NPH

provisions. For example, most facilities built a number of years ago in the eastern United States

were designed without consideration of potential earthquake hazard. It is, therefore, likely that

some older DOE facilities do not meet the earthquake criteria presented in this document.

For existing SSCs, an assessment must be made for the as-is condition. This assessment

includes reviewing drawings and conducting site visits to determine deviations from the

drawings and any in-service deterioration. In-place strength of the materials can be used when

available. Corrosive action and other aging processes should be considered. Evaluation of

B-7