SALEM
SALEM STUDY SYSTEM
Systems > 500KV

500KV

⚠️ DRAFT

500KV

Function

Provides offsite AC power to all station auxiliaries. Two physically independent 500kV transmission circuits supply station power transformers that step down voltage for plant distribution buses. The station can be safely shut down from full power in the event of loss of all offsite power sources. Total loss of all onsite and offsite AC power is not a design basis event. (UFSAR 8.1, 8.2)

Offsite Power (500kV)

  • Two physically independent 500kV transmission circuits
  • Station power transformers (13-4 kV) step down to 4160V for plant buses
  • Auxiliary power transformer (25-4-4 kV) provides alternate from generator bus
  • On unit trip, 4160V group buses automatically transfer from auxiliary transformer to station power transformer (UFSAR 8.2)

Tech Spec LCOs

  • TS 3/4.8 — Electrical — TS 3.8.1.1 requires 2 offsite circuits OPERABLE in Modes 1–4
  • 1 offsite circuit inoperable: 72 hours
  • 2 offsite circuits inoperable: 24 hours
Exam — 2020 Q81
AB.GRID-0001 Attachment 3: 500 KV Switchyard Voltage < 493 KV on any line → declare that off-site power source inoperable, initiate Station Load Curtailment. Individual lines: Orchard (5021), New Freedom (5024), Salem-Hope Creek Tie (5037). Each line's voltage is evaluated independently against the threshold.
Exam — 2019 Q62
Confirms the 493 KV threshold tested again: with Orchard at 492 KV, New Freedom at 494 KV, Salem-Hope Creek Tie at 497 KV, only Orchard is inoperable (492 < 493). Each line is evaluated independently. 494 KV is operable (not < 493), so New Freedom is NOT declared inoperable.
Exam — 2019 Q58
500KV line configuration: Orchard (5021), New Freedom (5024), and Salem-Hope Creek Tie-Line (5037) are the three 500KV lines. Loss of Orchard AND New Freedom with the Tie-Line still available = one independent AC circuit inoperable per TS 3.8.1.1. Action a.1 requires demonstrating OPERABILITY of the remaining circuit (SR 4.8.1.1.1.a) within 1 hour.

Connections