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Abnormals > AB.GRID-0001 — Grid Disturbance

AB.GRID-0001 — Grid Disturbance

⚠️ DRAFT

AB.GRID-0001 — Grid Disturbance

Purpose

Provides operator actions for responding to grid disturbances, including voltage and reactive load changes when a generating unit is lost.

Key Actions / Information

Exam — 2023 Q15
Loss of a Salem unit causes 500KV voltage to lower. The remaining unit's MVARs rise as it picks up a greater share of the reactive load on the grid.
Exam — 2023 Q88
Solar Magnetic Disturbance (SMD) > K-5 intensity with excess MVAR condition: per AB.GRID-0001 step 1.3, enter Attachment 2 (Solar Magnetic Disturbance) and initiate load reduction to <= 77.6% (942 MWe) at 15% per min using AB.LOAD-0001. Trap: a reactor trip is NOT required for SMD conditions (trip is directed per Attachment 1 for frequency <= 57.55 Hz, which is a different condition). Also, AB.GRID-0001 alone is not sufficient — AB.LOAD-0001 must also be performed.
Exam — 2020 Q81
Attachment 3 (Salem 500 KV Switchyard Low Voltage): if 500 KV Switchyard Voltage is < 493 KV, declare the associated off-site power source inoperable and initiate Station Load Curtailment IAW OP-AA-108-107-1001. Trap: Attachment 4 (500 KV Grid Instability) directs Generator Load Reduction at 15%/min max as specified by the ESO — this is a different condition from low switchyard voltage. Only lines with voltage below 493 KV are declared inoperable (e.g., 492 KV is inoperable, 495 KV is not).
Exam — 2019 Q62
Per AB.GRID-0001 CAS: 500 KV Switchyard voltage < 493 KV on any line → declare that A.C. Circuit (Off-Site Power Source) inoperable. With Orchard at 492 KV, New Freedom at 494 KV, and Salem-Hope Creek Tie at 497 KV: ONLY the Orchard line is inoperable (492 < 493). The other two lines remain operable (494 and 497 are both ≥ 493).
Exam — 2018 Q62
AB.GRID-0001 Attachment 2 (Solar Magnetic Disturbance) turbine load reduction: with turbine controls in OPERATOR MODE - AUTO, the PO will depress SMD#1 RUNBACK then GO on the TURBINE E-H CONTROL & STATUS touch screen monitor to initiate the generator load reduction to < 942 MW (~77.6% RTP) at 15%/min. SMD#1 RUNBACK alone is NOT sufficient — the GO button must also be depressed because SMD#1 RUNBACK is a preset setter position/ramp rate. Also, SMD#2 RUNBACK is a different preset — not used for this Attachment 2 evolution.

Connections