Confinement System Design Aspects by Facility Type

DOE-HDBK-1132-99

the closure of such dampers should not compromise confinement system

functions where the loss of confinement might pose a greater threat than the

spread of fire. In such cases, alternative fire protection means (e.g., duct

wrapping) should be substituted for fire barrier closure. In no case should a

sprinkler system be considered a fire barrier substitute. (All penetrations of a

fire barrier should be sealed, including conduit, cable trays, piping, and

ductwork. In the selection of seals, requirements for pressure and water-

tightness should be considered.)

1.2

CONFINEMENT SYSTEM DESIGN ASPECTS BY FACILITY TYPE

The preceding discussions of primary, secondary, and tertiary confinement generally

apply to all nuclear facilities. The degree of applicability should be determined on a

case-by-case basis. The following discussions provide some guidance on how to make

these determinations as a function of facility type.

A description of the facility types is included in Section 2. " ontainment"is addressed

in Section 2.10.8.

1.2.1

Plutonium Processing and Handling Facilities and Plutonium Storage

Facilities (PSFs). The degree of confinement required is generally based on

the most restrictive hazards anticipated. Therefore, the type, quantity, and form

(physical and chemical) of the materials to be stored should be considered. For

materials in a form not readily dispersible, a single confinement barrier may be

sufficient. However, for more readily dispersible materials, such as liquids and

powders, and for materials with inherent dispersal mechanisms, such as

pressurized cases and pyrophoric forms, multiple confinement barriers should

be considered. U.S. Nuclear Regulatory Commission (NRC) Regulatory Guide

(R.G.) 3.12, " eneral Design Guide for Ventilation Systems of Plutonium

Processing and Fuel Fabrication Plants,"provides useful guidance that should

be considered.

Generally, for the most restrictive cases anticipated, three types of confinement

systems should be considered:

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