Redundant Channel Separation:

DOE-HDBK-6004-99

Physical separation and independence should be provided for the four fusion device protection system

channels, identified as Channels 1, 2, 3, and 4, and for two load groups of safety related equipment,

identified as Trains A and B.

Redundant Channel Separation:

Raceways for the four redundant protection channels, engineered safety feature (ESF) actuation

signals, and the two safety related trains should be physically separated from each other. However,

Channel 1 and an ESF actuation signal channel may be run in the same raceway stack without

separation as Train A; also Channel 2 and an ESF actuation signal channel may be run in the same

raceway stack as Train B without separation. Channels 3 and 4 should conform to the separation

requirements as required. Separation should be maintained or a barrier should be used to the

terminating devices.

Non-redundant Separation:

Circuits for non-redundant balance of plant (BOP) functions originating at safety-class equipment

should be provided with isolation devices or may be run in raceways used by associated safety-class

circuits; however, the routing of such non-redundant circuits will be controlled the same as the safety-

class circuits.

Cable Tray Separation:

In general, physical separation of cable trays for redundant safety-class circuits should be maintained

by a minimum of three feet horizontal separation. Vertical stacking of redundant cable trays should

be avoided, if at all possible, but where such arrangement is employed, minimum vertical spacing

should be five feet between the two groups. Where this is not practicable, barriers will be provided

or rigid steel conduit and thermal barriers should be used. Divided cable trays should not be used to

separate redundant systems.

The cable tray system should be designed and installed according to the requirements of IEEE-384.

(see also Regulatory Guide 1.75).

Cable Color Coding

Cables for redundant systems should be color coded. Cable trays and conduits carrying these cables

should be identified by the same color marking or colored labels at intervals, when passing through

a barrier, or wherever confusion may exist. Acceptable color coding of the cables is as follows:

Safety Class:

Train A Red

Train B Green

Channel 1 Red