SUSTAINING OUR CURRENT NUCLEAR ASSETS

Transcription

1 SUSTAINING OUR CURRENT NUCLEAR ASSETS K. Huffman EPRI-Electric Power Research Institute, USA address of main Abstract. Examinination of today s United States big picture electrical generation strategies, both economic and environmental, shows a common assumption the current nuclear fleet will continue to operate successfully for at least 60 years. In accomplishing this current plants will provide significant quanitites of low cost electricity to the public and are a fundamental established contributor to limiting the quantity of CO 2 emitted to the environment in the production of electricity. Our industry should be honored by this confidence but should also recognize several challenges assocaited with fulfilling this trust. From an operating nuclear power plant perspective there are major challenges associated with both the physcial plants as well as the staff who ensure their successful operation. This paper largely addresseses the several issues related to the physcial plants material degradation issues, sustaining equipment reliability and addressing obsolescence/supply chain issues. Of the multiple people aspects important to the future of nuclear power this paper focuses on the impact the changing workforce has on the ability to sustain high levels of equipment relability and thus plant generation, economics. The importance of Total Asset Optimization Strategies to addressing these issues will be described as well as several key operative elements. 1. Introduction The importance of sustaining the operation of the existing United States nuclear fleet may be obvious to the informed. Secenario based studies performed by EPRI however provide further quantitative appreciation of this point. The key elements are: Significant economic controbution from high plant capacity factors and extended plant life Reduction of CO 2 compared to other proven generation capabilities of comparable size Provision of a bridge between the current nuclear fleet and the time when signifiant nuclear new build will come on line 1

2 FIG. 1. As an example of this quantification the increase in value in today s dollars that the electrical generation from the current U.S. fleet represents compared to its intial performance and 40 year life has been estimated to be of the order of 2 trillion dollars. FIG. 2. Sustaining the operation of the existing U.S. nuclear fleet poses several interesting points. Can we meet the challenge? Will we have the righter solutions at the right time? Can we make informed decisions now that will shape the future? 2

3 2. Asset Issus-Examples In the initial operation of the current plants much has been learned about the performance of materials installed in the plants primary system BWR recirculation piping, PWR steam generator tubing, PWR vessel head penetrations, etc. The industry has a proven ability to react and deal with these issues but as the plants enter their fourth through sixth decades of operation new material aging issues may be expected and more rapid response is needed. Proactive management of material degradation, including balance-of-plant systems is needed. FIG. 3. However, there are alternative strategies that my be applied to address material aging. Experience has shown that the degree of success depends on multiple factors, a key one being the extent of knowledge associated with the particular component and degredation or aging mechanism. FIG. 4. Finding solutions for physically and/or functionally obsolete plant equipment has been an ongoing challenge to the supply chain. Fortunately major plant outages have been avoided, however, many feel that major improvements can be made. Successful widespread use of digital electronic technology and expansion of coordinated relationships with suppliers providing quality components are solution examples. 3

4 FIG. 5. Again however, there are alternative solutions. In some situations retaining existing technology as long a practical can be employed. Another however focuses on adjopting the most modern technology and avoiding obsolescence issues, but at potentially a shorter life cycle for individual components. FIG. 6. Current plants operate at high sustained levels of equipment reliability supported significantly by highly experienced and knowledgeable individuals. As the industry embraces a new workforce new paradigms in how we accomplish this work will emerge. FIG. 7. [NEI-2005] Expanded use of an integration of electronic information, similar to other industries will be needed. Technology to integrate information is available; successful, visionary adaptation to our industry is still an evolving. Increased use of online equpiment condition monitoring coupled with advanced diagnostic tools based upon our extensive current experience provides a promising strategy. Alternatively or in conjunction with increased automation, processes of 4

5 capturing knowledge from highly experienced staff and transfering it to new staff becomes important 3. Strategy Evaluation Risks FIG. 8. [NEI-2005] For each asset issue there are potentially multiple strategies that may be applied going forward, as was illustrated in the prior section of this paper. Additionally combinations of strategies may be feasible in some situations. Selection of the appropriate strategy for nearterm decisions can be striaght forward. Selection is largely based upon known, available information quantified typically through cost information to differentiate alternatives, changes in information are often addressed as uncertainties or not addressed. When considering longterm performance these uncertainties or strategy risks can become dominant. Recognizing these as illustrated in the examples below supports more informed decision making. Table 1. Asset Issues Strategies (Examples) Strategy Risks (Examples) Material Aging Monitoring Management Degradation Rate Uncertainty Preventive Repair, Replacement Vendor Capacity Work Force Attrition Mentoring, Knowledge Capture Current Staff Burden Task Automation Cost Equipment Obsolescence Information Management New Technology Adaptation Sustaining Existing Equipment Highly Integrated Distributed Licensing Issues Ongoing Availability Transition Costs, Success Ongoing Technical Support 4. Total Asset Optimiation Strategies Effective Management of nuclear power plant assets benefits from a holistic view of the asset issues and the application of knowledge, typically staff and others expertise, as well as screening and evaluation tools. Use of expert opinion is valuable in recognizing issues and 5

6 developing sensitivities as illustrated below. A wide cross section of expertise particularly that outside of immediate near-term problem resolution is valuable. FIG. 9. The asset issues shown here are examples, others are anticipated. Since all issues may not have equal importance, screening of the issues is worthwhile. Simple screening or prioritization techniques, are usefull cross product of issue likelihood and issue consequence, as an example. Evaluation of risks identified for alternative strategies is often a function of multiple attributes many may be generic to most nuclear power plant issues others may be situational specific. 6

7 FIG. 10. The steps outlined here provide a basis for more informed strategy selection largely through, recognition of risks and evaluation of their potentional consequences. The process however must be dynamic. 5. Strategy Dynamics A dynamic strategy process is not dependent on or a victim of the risks associated with selected strategy elements but uses the recognition of the risks to improve the probability of successful outcomes. A material way to accomplish this is to apply effort to mitigate or eliminate risks. In the context of technology risks this can be accomplished by application of research. This can be realized on a networked basis as illustrated below with a largely United States perspective. 7

8 FIG. 11. This perspective illustrates the relationships that historically and currently exist between U.S. nuclear power plant operators and owners, typically electric utilities, and other stake holders. From a more local perspecitve, that of the Electric Power Research Institute (EPRI), this relationship can be focused on the major EPRI nuclear strategic research areas. These areas are guided by EPRI member advisors and benefit from processes such as that described here. FIG. 12. A second emphasis of a dynamic strategy process is the use of recognized alternatives, risks associated with alternatives and the inclusion of these in the strategy development and deployment. As discussed here the key characteristics related to the nuclear power plant assets are: 8

9 Nuclear specific focus and foundation Recognition of the multiple attributes important to specific strategies Flexilibity associated with retaining, changing and discarding strategy deployment options. 6. Benefits Discussions with chief nuclear officers often reveal their confidence that as an industry and as individual companies we can address the individual technical issues; but also concerns over how to most cost effectively get it all together. Success in accomplishing this positions them to truly be in control of the destiny of their plant assets. FIG. 13. Although this may appear to be an obvious point it also yields collateral benefits. Predictable, stable operating and capital budgets are a key outcome. FIG. 14. A major consideration at a senior management levels is credibility. Credibility with both financial stake holders owners and the investment community as well as organizations entrusted with safety oversight of nuclear facilities. 9

10 FIG. 15. The ultimate benefit is seen with these individuals responsible for the safe, economic operation of nuclear power plants the employees. Their confidence in their individual economic future and the realization that they support the successful operation of an important non-emitting energy source can not be understated. FIG. 16. As other industries have learned Total Asset Optimization Strategies are needed to integrate and balance technical solutions using asset management pricniples and techniques. REFERENCES [1] NEI Work Force Survey, November