Tritium Facility Safety Analysis and Regulatory Quantity Limits

DOE-HDBK-1129-99

3.3 Tritium Facility Safety Analysis and Regulatory Quantity Limits

A safety analysis is required by DOE Order 5480.23, "Nuclear Safety Analysis Reports," for all

nuclear facilities. Irrespective of these requirements, the good practices associated with the

implementation of integrated safety management principles necessitate that hazards be identified

and controlled, which is a major step in the safety analysis process.

3.3.1 Safety Analysis

3.3.1.a Facility Requirements

There are a few fundamental assumptions normally made when performing safety analyses on

tritium facilities, which if not satisfied will require more detailed analysis or corrective actions.

These include:

The integrity of the primary container should be ensured for all normal operations, anticipated

operational occurrences, and for the design basis accidents (DBA) it is required to withstand.

If the facility structure is not part of the secondary barrier , its failure as a result of severe

natural phenomena or other postulated DBAs should not prevent the primary container or the

secondary containment/confinement systems from performing their necessary safety

functions.

When secondary containers (secondaries) are used, a tritium effluent removal system to

handle tritium leakage from primary containers is recommended by this Handbook but not

required by regulations.

3.3.1.b Radiological Materials Inventory

Attachment 1 of DOE-STD-1027-92, "Hazard Categorization and Accident Analysis Techniques for

Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports," Change Notice 1 states,

"Additionally, material contained in Department of Transportation (DOT) Type B shipping

containers (with or without overpack) may be excluded from summation of a facility's radioactive

inventory if the Certificates of Compliance are kept current and the materials stored are authorized

by the Certificate. However, Type B containers (see Section 6.1) without an overpack should have

heat protection provided by the facility's fire suppression system."

Further guidance from this handbook expands this clarification to mean that if Type B containers

are currently certified to withstand the credible facility accidents in which they are located, then

their inventories could be excluded for SAR purposes. If the containers are not currently qualified

(qualifications expire on a fixed schedule), then their contents must be included in the summation

of facility inventory and be included in accident analyses, irrespective of accident conditions. If,

however, the container is currently certified, then a comparison of the conditions resulting from

transportation and facility accidents is performed. For example, consider a currently certified Type

B container that has been qualified to withstand fire and crush loads (i.e., Type B Hypothetical

Accident Crush Test loads) associated with a transportation accident. If these transportation

accident conditions are more severe than the associated credible facility accident conditions (e.g.,

fire and seismic crush loads), then the inventory in these containers can be excluded (irrespective

of fire suppression system coverage) in the safety analysis. If the facility fire conditions exceed the

transportation fire conditions, the inventory is included. Note that credit for safety-grade or safety-