10. Local Power Protection (ЛАЗ)

LAZ serves the same purpose as PK-AZ but operates locally, responding to conditions in each individual zone rather than the core as a whole. It is enabled by the key switch on panel 3A, where its setpoint is also set.

Each LAZ zone shares two probes with LAR. Near LAR rod — probe 1 (lower left) and probe 3 (upper right). The deviation between the LAZ setpoint and the current probe readings is visible on the imbalance indicators on wall panel 3.

LAZ inserts its rods under two conditions:

• in PK-Mode when its zone deviates from the LAR setpoint by more than 2%,
• or when both of its probes reach the emergency threshold.

Adjusting LAZ

Balancing LAZ is the most demanding task in routine reactor operation. Each zone has two rods that must be adjusted together to bring both probe readings into balance around the setpoint. Watch the imbalance indicators on wall panel 3 closely — the goal is to have both probes sitting evenly on either side of the setpoint rather than pulling in opposite directions. Small, deliberate rod movements are essential, as the two probes respond differently depending on which rod is moved.