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NERC Case Notes: Reliability Standard IRO-010-1a

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NP20-6-000: Bonneville Power Administration

Reliability Standard: TOP-002-2.1b; TOP-004-2; TOP-007-0; IRO-005-3.1(a); IRO-010-1a

Requirement: TOP-002-2.1b: R1, R4; TOP-004-2: R1; TOP-007-0: R1; IRO-005-3.1(a): R9; IRO-010-1a: R3; IRO-005-3.1a: R9; IRO-0101a: R3

Violation ID: WECC2017017579, WECC2017017591, WECC2017017588, WECC2017017589, WECC2017017584, WECC2017017585

Method of Discovery: Self-Report

Violation Risk Factor: Medium (TOP-002-2.1b, IRO-010-1a); High (TOP-007-0); Lower (IRO-005-3.1a)

Violation Severity Level: High (TOP-002-2.1b R1); Severe (IRO-010-1a, IRO-005-3.1a, TOP-007-0); Moderate (TOP -002-2.1b R4)

Region: WECC

Issue: On May 18, 2017, BPA submitted a Self-Report stating, as a Transmission Operator (TOP), it had a potential noncompliance with TOP-002-2.1b R1. On November 30, 2016, BPA was implementing an outage as a part of the boundary Remedial Action Scheme (RAS), which entailed line loss logic for three separate lines. BPA did not correctly implement the published Study Limit Information Memo (SLIM), as is required by BPA's Operating Plan during the outage. The Dispatcher, implemented a restricted generation limit of 650 MW at the boundary generation station, rather than at the flowgate as specified. BPA did not lower the boundary SOL from 1300 MW to 650 MW. This mistake resulted in BPA operating a boundary SOL that was 650 MW higher than the setting should have been. As a result, the boundary RAS was operated in a degraded state. In addition, BPA had not included the boundary RAS in the list of Special Protection Systems that were incorporated into the Coordinated Outage System and therefore not reported to BPA's RC.

The outage work that resulted in the boundary RAS is usually completed one line at a time. When the SLIM was issued in this case, the Dispatcher also reviewed a Dispatch Standing Order (DSO) but the guidance was not applicable, which resulted in BPA not manually entering the SOL into the control system and causing the alarm monitoring to not alert to three SOL exceedances between 2:15 PM and 2:45 PM on November 30, 2016. Due to the lack of alarms, the Dispatcher did not realize there were SOL exceedances.

Finding: WECC determined these violations in aggregate posed a moderate risk and did not pose a serious and substantial risk to the reliability of the BPS. In this case, BPA was already operating its system with the RAS in a degraded state. If BPA were to have lost another line, the RAS could have caused a loss of load and potentially opened the remaining lines entirely. Further, BPA implemented weak preventative controls but effective monitoring controls as this issue was discovered during a routine monitoring activity nine days after the issue occurred, on December 9, 2016. As compensation, instead of setting the correct SOL, BPA instructed the main generation station for these lines to limit its generation to 650 MW. This action by BPA reduced the risk because instead of changing the SOL to address its mistake, it instructed the main generation station to limit its generation which then lowered the flows on the path without changing the SOL.

Penalty: $0

Duration of Violation: About 7 ½ hours on November 30, 2016

FERC Order: Issued December 30, 2019 (no further review)