Special Occupancies - hdbk10920077

DOE-HDBK-1092-98

5.0 SPECIAL OCCUPANCIES

This section covers the specific requirements and information for installing electrical equipment and

wiring in explosive and hazardous locations and underground facilities. Classifications of areas or

locations with respect to hazardous conditions are discussed. Information is provided on the correct

methods and techniques needed for system grounding, lightning protection, and controlling of static

5.1 EXPLOSIVES

This section references DOE M440.1-1, "DOE Explosives Safety Manual," NFPA 70 (NEC), NFPA

77, NFPA 780, and DOD 6055.9-STD, "DOD Ammunition and Explosives Safety Standards."

These standards and manuals should be referenced to ensure safe and reliable installations of

electrical equipment and wiring methods in explosive and hazardous locations.

5.1.1 EVACUATION

Whenever an electrical storm approaches, personnel shall exit any location where a hazard exists

from explosives being detonated by lightning. Evacuation may be necessary from locations listed

below:

1. All outdoor locations, locations in buildings that do not have lightning protection, and

locations within inhabited building distance of the hazard. (When an electrical storm is

imminent, work with explosives operations shall not be undertaken.)

2. Locations (with or without lightning protection) where operations use electrostatic-sensitive

bulk explosives or electroexplosive devices (EEDs).

5.1.2 SHUTDOWN OF OPERATIONS

The following guidelines shall be used for shutdown of an operation during an electrical storm:

1. Process equipment containing explosives shall be shut down as soon as safety permits.

2. When buildings or bays containing explosives are evacuated, functions that cannot be shut

down immediately shall be operated by the minimum number of personnel required for safe

shutdown. When the operation has been brought to a safe condition, those remaining shall

evacuate.

3. Automatic emergency power equipment shall be provided if electrical power is critical to an

explosives operation during a power shutdown or interruption.

5.1.3 LIGHTNING PROTECTION

It is DOE policy (See DOE M440.1-1, "DOE Explosives Safety Manual") to install lightning

protection on all facilities used for storage, processing, and handling of explosive materials where

5-1