1 / 22

Margin Management

Margin Management. Plant Shutdowns. Late 1990’s – numerous “surprise” long-term plant shutdowns Shutdowns resulted when a history of events (equipment failures / complicated transients) lowered confidence in plant and raised scrutiny by external organizations

prentice
Télécharger la présentation

Margin Management

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Margin Management

  2. Plant Shutdowns • Late 1990’s – numerous “surprise” long-term plant shutdowns • Shutdowns resulted when a history of events (equipment failures / complicated transients) lowered confidence in plant and raised scrutiny by external organizations • General lack of “rigor” in evaluating and correcting problems

  3. Plant Shutdowns • Design issues evident shortly before or after shutdown • Resolution and extent of condition extended shutdown considerably • Key issues included • Accident analysis – translation into operation • Operating margin • Physical condition of plant not in conformance

  4. Plant Shutdowns Similar issues and causes and contributors are evident in plants today • Palo Verde • Kewaunee • Point Beach • Others?

  5. Basic Approach • INPO does: • Encourage more systematic consideration • Look for margin contributors to performance • Promote identification and resolution of “latent problems: • Promote site-wide approach to MM • INPO does not: • Dictate how much margin was acceptable • Prescribe how to manage • Push plants to build another complicated infrastructure • Push utilities to quantify unknown margins unless there was a risk / need.

  6. Status Today • Higher awareness and consideration of margins • Margin preservation and improvement is more explicitly considered during • Prioritization of equipment improvements • Design change options • Reconstitution of design basis, calculations, etc.

  7. Gaps Today • No industry consensus on: • Attributes/principles of margin management • Which margins are of most concern (i.e. critical equipment functions) • Some stations elected not to establish a “program” but normal processes don't have explicit standards and expectations • Most “programs” focus on identification & prioritization – little guidance that describes the desired site-wide management and organizational behaviors • At some stations – MM still viewed as an engineering activity – not embraced by the full management team • May not be rigorous if BOP

  8. CM & EN Evaluation Results Data Through 3/31/2008

  9. Guidance Document Development • Industry working group meeting at INPO April 2008 • 25 attendees • Current schedule to publish the document is end of 2008. • NX-1068 Exelon Margin Management

  10. Key Elements • Understanding margin • Identifying margin concerns • Evaluating margin concerns • Prioritizing margin issues • Resolving margin issues • Roles and responsibilities • Process considerations • Periodic assessment and communications

  11. Understanding margin • Objective • The concept of design and operating margin are defined, communicated, and understood by station personnel • Attributes • The definition of various margins is provided to plant personnel • Concepts understood by appropriate personnel • Location of limits and their bases are communicated to plant personnel • Training tools developed at plants

  12. Identifying margin concerns • Objective • Margin concerns are identified and documented by station personnel • Attributes • Scope of SSCs covered by program defined • Cross disciplinary input used • Existing processes identify margin concerns • Corrective Action Program • Self Assessments • Latent Issues Review • System Health Reports • Margins are identified when new plant configurations are implemented

  13. Evaluating Margin Concerns • Objective • Margin concerns are sufficiently understood to allow for proper prioritization • Attributes • Operating and design requirements are known • SSC capability is known • The resulting margin is assessed • The aggregate impact of margin issues is evaluated, as required • The associated risk to plant safety and reliability is established

  14. Prioritizing margin issues • Objective • Conditions that result in unacceptable design and operating margins are prioritized commensurate with the associated risk to plant safety and reliability • Attributes • Prioritization based on safety and reliability • Cross-disciplinary reviews determine priority • The prioritization scheme correlates to site prioritization • Management reviews, validates priority, and provides sponsorship

  15. Resolving Margin Issues • Objective • Plans are comprehensive and address interim compensatory measures and contingencies • Attributes • Plans developed • Associated actions are captured and tracked in the appropriate station work process • Interim actions and contingencies developed as req’d

  16. Roles and Responsibilities • Objective • Roles and responsibilities for monitoring, protecting, and resolving operating and design margins are defined and understood by plant personnel • Attributes • Site management sponsors the disposition of margin concerns and provides effective oversight of margin management implementation • Engineering is the champion of margin management and owns design margins • Operations owns operating margin • Maintenance ensures equipment maintained and tested to ensure performance requirement are met

  17. Process Considerations • Objective • Sufficient station processes exist to allow margin concerns to be identified, prioritized and dispositioned • Attributes • Station personnel are aware and consistently apply the process(es) designated to identify, prioritize and disposition margin issue • Processes revised to drive consideration (institutionalized)

  18. Periodic assessment and communications • Objective • The effectiveness of margin management decisions is periodically evaluated and communications reinforce the importance of effective margin management • Attributes • Periodic oversight reviews by station leadership • Periodic communications reinforce the importance of effective margin management

  19. Examples of Margin Areas for Improvement • Weaknesses in identifying and resolving low operating and design margin issues are affecting equipment that is important to safety. • Compensatory measures for low operating and design margins are affecting plant operations. • Power uprates reducing BWR power-to-flow map operating region and operation outside the design basis • Excessive cooler flows erode coils and cause unplanned LCOs • EDG loading margin and voltage response

  20. Examples of Margin Assistance Recommendations • Improve awareness of margin shortfalls during high-risk and emergent events. • Improve communications and understanding of margin issues. • Improve pathways of highlighting margin issues in existing plant processes. • Develop clear margin issues and follow a systematic process to resolve shortfalls.

More Related