The Cost of Poor Reliability for Future Particle Accelerator Driven Systems in the UK Energy Market

Transcription

1 The Cost of Poor Reliability for Future Particle Accelerator Driven Systems in the UK Energy Market Steven J Steer, William J Nuttall, Geoff T Parks & Leonardo V N Gonçalves

2 Accelerator Driven Nuclear Power A design Concept Feasibility Study UK Engineering and Physical Sciences Research Council (EPSRC) funded project Investigating the potential of accelerator assisted nuclear reactor designs both as radioactive waste transmuters and as commercial power generators The study is dedicated to examining the entire picture: Can the engineering challenges faced by accelerators be overcome? Is there a market for the technology and can an economically viable design be realised. Quantifying the economics of reliability Reliability is a critical issue regarding using accelerators in the energy market As a part of the feasibility study, the value lost due to poor reliability has been predicted

3 Uranium Supply Nuclear Fuel (OECD NEA & IAEA report Uranium 2007: Resources, Production and Demand) At 2006 rates of consumption, Identified Resources are sufficient for about 100 years Five options for increasing the available energy I. Increase spent fuel reprocessing II. Switch to fusion III. Extract uranium from seawater IV. Fast fission (increased fuel burn efficiency) V. Replace uranium with thorium Accelerator Drive Subcritical Reactor (ADSR) This design concept addresses: thorium and fuel efficiency and (optional) fuel recycling

4 Accelerator Driven Subcritical Reactors Without the accelerator the nuclear core cannot sustain fission Accelerator system provides an additional kick to perpetuate fission Switching off the accelerator system shuts down the reactor this adds a safety failsafe Unplanned accelerator outages ( beam trips ) therefore also cause reactor shutdowns The implications of trips Potentially damage the core Cost of fulfilling sales contracts The economic cost of beam trips has been predicted for ADSRs of any chosen reliability

5 System Buy Price (2006 /MWh) Real Market Conditions UK market Using 2006 historical data Selling 600MWe to market Expected sales position Large capital costs, therefore: base load electricity Price takes at the long-term Market Index Price (MIP) During (instantaneous) unplanned shutdown: Pay the Nat. Grid the System Buy Price (SBP) for honouring contracts* Arrange short-term contracts at MIP to avoid paying the SBP 600 *The model modifies the historical SBP by + 100/MWh to simulate the impact of the failure on the grid assumption under review Data for the 2006 SBP in 30 minute periods minute period of 2006

6 Example: Cost of a Single 24 hour trip Select a random 24 hour (48 periods) from 2006 Generate success rate of arranging short-term contracts Repeat for 10,000 iterations Example of 3 iterations of the simulation 1 period = 30 minutes

7 Frequency Example: Cost of a Single 24 hour trip (cont.d) 10,000 iterations of the cost of a 24 hour shutdown. 16% Red: Loss Made Blue: Opportunity Cost 12% 8% 4% Mean Opportunity Cost: 1.37 million Standard Deviation: 0.31 million 0% Cost (2006 )

8 Cost of failures 30 minutes 24 hours in duration Opportunity Cost Repeat the process for all periods up to a maximum failure duration of 48 periods (24 hours) 0 30 minute period Plotted are the mean and standard deviation cost of failure for failure durations up to 48 periods

9 Cost (2006 Million) Trip Frequency Trip Frequency data of Existing Accelerators Observed Relative frequency of trips of different durations 2/3 power law Relationship: Frequency vs. durations greater than or equal to time t 50% uniform volatility about the mean (J. Galambos et al.) 1000,0 100,0 Trip frequency relative to a single 48 unit in duration failure 10, ,0 0, Duration of Failure (30 minute periods) Cost of failure per 48 unit in duration failure Failure duration in 30 minute periods

10 An ADSR of the user s specifications It is not certain what accelerator system reliability and load factor will be achieved An accelerator system like that required by an ADSR has never been built Research facilities are the closest existing match their research interests and (publically funded) budgets change priorities The model has been constructed so that the user can identify the cost of failure of their ADSR An ADSR with a lifetime of 40 years This is the standard life expectancy of a nuclear power station (Calculations have been repeated for a 60 year lifetime) A nominal failure rate is scaled to the user s rate The nominal rate is chosen to be 1% of the ADSR s life (For computational ease 0.77% has been used thus far, the presented numbers are for this 0.77% rate...this is going to be corrected when the analysis is completed)

11 Accounting for Inflation and Discounted Cash Flow Frequency Annually inflate electricity prices and discounted cash flow rate This requires that the cost of failure per year is identified Using the nominal shutdown rate, generate the trips experienced in a year Generate the cost of failure of each trip Repeat for 10,000 iterations 8% 6% 4% Cost of failure per year (prior to accounting for inflation and DCF) 2% 0% Cost per year for (2006 )

12 Opportunity Cost (2006 Millions) The Nominal Lifetime Cost of Failure % 6% 8% 10% 12% 14% Discounted Cash Flow Inflation rate 0.0% 1.5% 3.0% 4.5% 6.0% Nominal Lifetime Cost of Failure for a range of inflation and DCF rates Scaling from the nominal to the actual failure rate 1) Choose an inflation and DCF rate, then determine the corresponding nominal cost of failure 2) Choose a load factor and reliability coefficient and scale:

13 Opportunity Cost (2006 Millions) The Expected Cost of Failure of a Contemporary Accelerator System Existing Accelerator systems realise a Load Factor of 65% and a Reliability coefficient of 90% % 6% 8% 10% 12% 14% Discounted Cash Flow 0.0% 1.5% 3.0% 4.5% 6.0% For an Inflation rate of 3% and a (nominal) DCF rate of 10%: The lifetime cost of failure is: 600 million (PV 2006 )

14 PDS-XADS Research & Development Efforts Preliminary Design Studies experimental Accelerator Driven System Can be considered the best case engineering will achieve It expects 5 trips per year Assuming each trip is 24 hours in duration... Inflation: 3%, DCF rate: 10%: The lifetime Cost of Failure will be = 100 million CORDIS Contract Number: FIKW-CT Engineering Expenditure that takes existing technology to the best case technology should not exceed 500 million (Inflation 3%; DCF 10%; PV 2006 )

15 Overview A fleet of ADSRs will all benefit from the research Building multiple ADSRs will significantly increase the budget for improving the design Summary A monte carlo technique has been applied to asses the value of reliability engineering of ADSRs in the nuclear power industry The model identifies the cost of failure using data from existing systems and markets It defines quantitative goals for the budget engineers need to work within in order to maximise the value of future technology The model has been designed to be flexible, making it applicable to any chosen specifications (i.e. Load factor, reliability, inflation rate, DCF rate)