ML060170638
| ML060170638 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 01/17/2006 |
| From: | PJM Interconnection |
| To: | Office of Nuclear Reactor Regulation |
| Matthew McConnell NRR/DE/EEIB | |
| References | |
| Download: ML060170638 (12) | |
Text
ENCLOSURE 8
©2003 PJM Voltage Control for Nuclear Power Plants in PJM NRC Public Meeting January 9-10, 2006 ADAMS/ACCESSION NO.: ML060170638
©2003 PJM PJM Confidential Overview of PJM 2002 Data Population - 51 million Generating sources - 1,271, with diverse fuel types Generating capacity - 164,597 megawatts Peak demand - 135,000 megawatts Annual energy delivery - 700 million megawatt-hours Transmission lines - 56,070 miles Members/customers - more than 390 Cumulative billing - $28 billion since 1997 NPPs are a key energy source in the PJM market area PJM Interconnection serves as the regional transmission organization (RTO) for a 164,260-square-mile area that cover all or parts of Delaware, Indiana, Illinois, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia.
©2003 PJM PJM Confidential Overview of PJMNuclear Plants
- Salem 1&2/Hope Creek
- Salem 1&2/Hope Creek
- Quad Cities1&2
- Byron 1&2
- Braidwood 1&2
- DC Cook 1&2
- LaSalle1&2
- Susquehanna 1&2
- North Anna 1&2
- Surry 1&2
- Beaver Valley 1&2
- TMI
- Calvert Cliffs 1&2
- Peach Bottom 2&3
- Oyster Creek
- Limerick 1&2 31 Nuclear Units
- Dresden 2&3
©2003 PJM PJM Confidential PJM Nuclear Owners/Operators Users Group Created by the owners as a feature of PJM governance (PJM staff facilitates and provides administrative support)
Broad participation from the nuclear owners: AEP, AmerGen, Constellation, Dominion, Exelon, First Energy, PPL, and PSEG Process Nuclear owners work with PJM staff and the PJM Operating Committee (transmission owners and non-nuclear generators) to establish and document requirements that address NPP concerns Operating requirements and procedures are documented in the PJM Manuals and become mandatory via the authority that flows from the PJM Operating Agreement, which all PJM members execute
©2003 PJM PJM Confidential PJM Operational Responsibility Relative to NPPs Operate transmission system within limits (thermal, voltage, stability), while honoring specific, more restrictive limits that the NPPs may be required to maintain
- Tools used:
- Real Time Contingency Analysis (RTCA) application, which runs every minute, which analyzes ~4,000 contingencies
- Transfer Limit Calculator (TLC) application, which runs every 5 minutes, which establishes transfer limits to prevent voltage collapse scenarios
©2003 PJM PJM Confidential PJM Voltage Standards and Operational Philosophy
©2003 PJM PJM Confidential Mitigation Protocols for NPP Voltage Limits
- Communication
- NPP, Transmission Owner, PJM
- Information Exchange
- Recognize the special needs of NPPs to have actual voltage information
- Take Action
- Run generation out of economic merit order, as necessary, to prevent violation of the limit
[For details, see PJM Manual M-3, Transmission Operations, at:
http://www.pjm.com/contributions/pjm-manuals/pdf/m03v18.pdf, pgs. 38-41]
©2003 PJM PJM Confidential Exelon Example Issue: Required post-contingency voltage (upon loss of the plant) at ComEd-area NPPs is more restrictive than the PJM Base Line limit.
PJM builds an additional contingency in RTCA to monitor post-contingency voltage If PJM calculates a simulated violation, the Exelon Nuclear Duty Officer (NDO) is notified.
NDO decides whether (1) to authorize PJM to run generation to mitigate, or (2) to take action at the NPP to mitigate If NDO authorizes generation, PJM dispatches generators on, as necessary, to control the post-contingency voltage within limits If the limit is violated, Exelon declares an LCO until the post-contingency voltage is brought within limits.
©2003 PJM PJM Confidential Maintenance Risk Assessments PJM Outage Coordination Process
>30 Days From Start
- Owner requests the outage
- PJM accepts/rejects request, based on availability of required reserves, and transmission reliability 1-7 Days From Start
- Repeated transmission analysis takes place to ensure that all reliability limits are respected, given the system topology anticipated during the outage Outage Start Day
- Owner requests to take the facility out of service
- PJM analyzes the system as it currently exists to verify that the outage can proceed without violating reliability limits
- PJM permits the facility to be switched out of service, if the analytical results are satisfactory
©2003 PJM PJM Confidential Draft Generic Letter Open Questions from Grid Perspective What are degraded grid reliability conditions that would warrantthe rescheduling of grid-risk-sensitive maintenance activities ? (from draft Generic Letter)
Could degraded grid reliability conditions be:
Circuit breaker maintenance in the substation?
Outages of adjacent transmission lines?
Routine maintenance of protection systems?
High load conditions?
And who decides?
Licenseemay not be a good judge of grid risks TSOwill not be a good judge of NPP risks
©2003 PJM PJM Confidential Draft Generic Letter Open Questions from Grid Perspective If the grid reliability evaluation indicates that degraded grid reliability conditions may exist during maintenance activities, the licensee should consider rescheduling any grid-risk-sensitive maintenance activities (i.e., activities that tend to increase the likelihood of a plant trip, increase LOOP frequency, or reduce the capability to cope with a LOOP or SBO). (from draft Generic Letter)
When is maintenance performed?
Not in maintenance seasons (Spring or Fall)
Not in high load scenarios (Winter or Summer)
©2003 PJM PJM Confidential Draft Generic Letter Open Questions from Grid Perspective Describe your formal agreements with your transmission system operator (TSO) to promptly notify you when conditions of the surrounding grid are such that degraded voltage (i.e., below TS requirements) or LOOP could occur following a trip of the reactor unit(s). (from draft Generic Letter)
What is the NRC vision of agreements?
Individual bi-lateral agreements between PJM and each NPP? Tri-lateral with PJM and transmission owner?
PJM perspective:
All PJM members (transmission owners, nuclear owners, non-nuclear owners, marketers) sign PJM Operating Agreement which binds all members to conform to requirements in the PJM Manuals PJM Manuals contain all operational requirements and procedures and are maintained by PJM in conjunction with the PJM committees
©2003 PJM PJM Confidential Draft Generic Letter Open Questions from Grid Perspective Describe the procedures to periodically check with the TSO to determine the grid condition and ascertain any conditions that would require a notification. If you do not have procedures, describe how you assess grid condition that would require notifications. (from draft Generic Letter)
PJM perspective: 31 nuclear units, 8 owners, 16 transmission owners There have to be protocols in place to require the necessary notifications and a level of trust that the notifications will occur when required. Any regime other than exception reporting will quickly become a significant burden to the shift personnel at the NPPs, TSOs, and the transmission owners.
©2003 PJM PJM Confidential Draft Generic Letter Open Questions from Grid Perspective Consistent with the recommendations in Section 2 of RG 1.155, you are expected to have established an agreement with your plants TSO that identifies local power sources that could be made available to resupply your plant following a LOOP event. (from draft Generic Letter)
PJM Perspective:
PJM restoration procedures provides deference to the special needs of NPPs. The possible system configurations that might exist in the wake of a LOOP are almost impossible to predict and assess. In the PJM area, the transmission and generation sources are so densely situated that delineating particular generation and/or transmission sources for a particular NPP restoration scenario is very problematic.