Meteorological Data Requirements and Regulatory Conformance Issues

Transcription

1 ESP / COL Applications Meteorological Data Requirements and Regulatory Conformance Issues Ping Wan Bechtel Power Corporation The Eleventh Nuclear Utility Meteorological Data Users Group Meeting October 2006

2 U.S. Nuclear Energy Quick facts nuclear plants - 20% of the nation s electricity % capacity factor - No new contracts since No new plants since >23,000 MWe of new capacity since

3 U.S. Energy Demand Commercial Use Residential Use Industrial Use Source: U.S. Department of Energy 3

4 U.S./DOE - Nuclear Power 2010 Call for building new nuclear power plants by Support engineering of advanced designs. Validate regulatory process. Develop concepts to mitigate financing risks. Cost share industry/government. 4

5 Proven Technology Approved - ABWR - AP AP System 80+ Certification Process - ESBWR - ACR EPR 5

6 Part 52 Licensing Process Siting Equivalent Environmental Information OR Early Site Permit Application Staff Review ACRS Review Mandatory Hearing Early Site Permit Decision COL Application for Combined License (COL) Staff Review ACRS Review Mandatory Hearing Decision on COL Construction and ITAAC Completion Finding on ITAAC Application for Design Certification Staff Review ACRS Review Certification Rulemaking/ Hearing Decision on Design Certification OR Design Equivalent Design Information 6

7 Demonstrating the Process Energy Bill NP-2010 % &'!"# $ "$ %( 7

8 Preparing ESP and/or COL Applications Meteorological Data Requirements

9 Used Of Meteorological Data Use of Data Application Development Regulatory Review Plant Operation Atmospheric dispersion estimates for both postulated accidental and routine airborne releases of effluents X X X Comparison with offsite sources to determine the appropriateness of climatological data use for design considerations X X Evaluation of environmental risks from radiological consequences of a spectrum of accidents X X Evaluation of non-radiological environmental impacts X X Development of emergency response plans X X X 9

10 Regulatory Requirements and Guidance NRC Regulations NRC Regulatory Guidance NRC Review Guidance Industry Standards / Guidelines 10

11 Regulatory Requirements and Guidance (conti-) Sample List R.G (Proposed Rev. 1) RS-002 (2003) NUREG-0800,Draft Rev. 3 (1996) NUREG-1555 (1999) Draft DG 1145 (2006) NUREG-0654, 0696, 0737 ANS / ANSI 3.11 (2005) NEI (ESP) & (COL) 11

12 Meteorological Tower and Instrument Siting The objective of the onsite meteorological program is to provide measurements which represent the general site area as well as the overall site meteorology without structure influence. Essential siting Criteria (R.G. 1.23, Proposed Rev. 1) Base of the tower at approximately the same elevation as the finished plant grade of the new units Location of tower upwind of the existing and new plant cooling system Upper measurement level of the tower within the TIBL for coastal or lakeshore sites Sensor location at least 10 obstruction heights away from such obstructions Wind sensors located on mast away from tower structure influence Ambient temperature and humidity sensors located away from existing and proposed moisture sources 12

13 Meteorological Parameters Measured On the primary tower Wind speed and wind direction at 2 levels (at 10 meters and 60 meters, which generally coincides with the routine release level for LWRs), and at the stack release height (if applicable) Delta-T between 10 meters and 60 meters, and 10 meters and the stack release height Ambient temperature at 10 meters Atmospheric moisture at 10 meters, and at the top of the cooling tower (if applicable) Precipitation at or near the tower At the backup tower Wind speed, wind direction, and horizontal wind direction fluctuation at 10 meters 13

14 Length & Currentness of Records For an ESP Application At least one annual cycle of onsite meteorological data Meteorological data in the form of joint frequency distribution of wind speed, wind direction by atmospheric stability class as described in R.G An electronic listing of all hourly averaged data For a COL Application At least 2 consecutive annual cycles (preferably 3 or more whole years), including the most recent 1-year period Meteorological data format and electronic listing same as for the ESP Application 14

15 Other Regulatory Requirements Data Acquisition and Data Reduction System Accuracy Instrument Surveillance, and Quality Assurance and Documentation Regulatory Requirements on these areas can be found in various Regulatory Guides (e.g., R.G. 1.23, Proposed Rev. 1 & Draft DG 1145) and Review Guidance Documents (e.g., RS-002, NUREG-0800, Draft Rev. 3 and NUREG-1555) 15

16 Preparing ESP and/or COL Applications Regulatory Conformance Issues

17 Use of Existing Meteorological Data Conformance Issues Confirm Representativeness of the Data Met tower and instrument siting Meteorological parameters measured Determine Data Quality Data acquisition (data recording/transmission) Data reduction (data processing/substitution) Instrument surveillance (calibration, maintenance, QA/QC) Assess Completeness of the Data Set Annual data recovery rates Length of records 17

18 Confirm Representativeness of Data Met tower and sensor siting Influence/Interference factors (including existing & proposed units) to be considered: Surrounding terrain (e.g., hills, rivers & valley) Nearby natural- & man-made obstructions (e.g., trees & plant structures Plant heat dissipation system (e.g., lakes & cooling towers) Related construction activities (e.g., earthmoving, heavy equipment hauling & concrete batch plant operation) Met tower & the new units have similar meteorological exposure. Sensor elevations & measurements (wind speed, wind direction, delta-t, dew point & precipitation) on the met tower meet regulatory requirements for the new units 18

19 Upper Level Wind and Temperature Measurement Heights R.G Requirements at least 2 levels (e.g., approximately 10 and 60 meters) of wind measurements Implicitly indicated that the 60 meters, upper measurement level as the level of the routine releases Conformance Issues Some of the new reactor designs (e.g., AP1000, EPR & ABWR) could have radiological release point higher or lower than 60 meters Ensure that separation between the Delta-T levels (i.e., 10 meters and the upper level) is no less than 30 meters. Ensure that the proposed data collection system (existing or new) is capable of capturing representative data. 19

20 Dew Point Measurement Height R.G Requirements Monitor atmospheric moisture at approx. 10 meters and at a height where the measurements represent the resultant atmospheric moisture content, if cooling towers are used Conformance Issues Majority of U.S. nuclear plants measured Dew Point at 10 meters only (i.e., once-through cooling system) Additional Dew Point measurements at higher level may be required for new plants, if cooling tower are used. Ensure that the Dew Point data are adequate and reliable, when use existing data. (Dew Point sensors are know to be difficult to maintain.) 20

21 Thermal Internal Boundary Layer Effects R.G 1.23 Requirements For sites near a large body of water, the upper measurement level should be within the TIBL during sea or lake breeze conditions. Conformance Issues Depending on the relative location of the met tower to the TIBL, and to the proposed units, X/Q estimates for the new units could be under-predicted, unaffected or overpredicted. The impacts from under-predictions need to be accurately quantified and factored in making the site-specific X/Q estimate. The Potential implications on facility design due to overpredictions need to be evaluated. 21

22 Typical TIBL Event 22

23 Data Substitution Regulatory Requirements There are many methods of acquiring data from meteorological measurement systems which are acceptable to the NRC Staff. Conformance Issues Valid measurements from a redundant sensor at the same level or at a different level (with adjustment) can be used. Replacement of a large amount of missing primary tower Delta-T data with back-up tower sigma-theta data from a nearby should be avoided. 23

24 Use of Nearby Existing or Regional Data Regulatory Requirements No clear regulatory guidance on the subject available Draft DG-1145 indirectly suggested: Wind rose comparisons (both seasonal and yearly) X/Q estimates based on XOQDOQ, PAVAN and/or ARCON96 Conformance Issues Using reactor specific DCD limit values in lieu of making direct X/Q calculations can be considered. However, one could lose the design margin that is potentially afforded by using onsite met data. 24

25 Climatic Representative Regulatory Requirements Evidence should be provided to show how well the existing met data represent long-term conditions at the proposed site. Conformance Issues The climatic representativeness of the onsite met data can be checked by comparison with nearby stations with similar geographical locations and topographical settings that have reliable long-term met data. Alternatively, a demonstration of representativeness can be made using data collected by the same system, if a long-term valid and reliable data base is readily available. 25

26 Issuance of R.G. 1.23, Third Proposed Rev. 1 Status NRC plans to issue a Draft Revision 1 of R.G by October 2006 Conformance Issue Issuance of Draft R.G. 1.23, Rev. 1 may be late coming for those applicants with submittals planned for 2007 or NRC indicated no major changes expected in the Draft Rev. 1. However, the applicants must be prepared to address any changes in the revision. 26

27 Dispersion Modeling Guidance & Tools Sample List Types of X/Q Estimates NRC Guidance Tools Routine & Accidental Radiological Releases Control Room Habitability Evaluation (for both chemical and radiological releases) Emergency Planning (Near Real-time Predictions) (* Modifications required adding plume tracking capability) Environmental Impacts of Cooling Tower Plume R.G R.G R.G NUREG/CR-6210 R.G NUREG-0570 NUREG/CR-1152 R.G NUREG-0654 NUREG-0696, 0737 No specific guidance XOQDOQ PAVAN ARCON96 HABIT No NRCsponsored codes MESODIF-II* CALPUFF* EPRI Model - SACTI 27

28 Hypothetical Deployment Schedule and Financial Commitment for New Nuclear Generation ESP Year 28 SER Issued EIS Issued LWA-1 ESP Issued Submit Application Start Application COL Issued SER Issued LWA-2 Issued Submit Application Hearings ESP Prepare ESP Review Start Application Hearings COL Preparation COL Review COL First Safety-Related Concrete ~ ~ ~ ~ Site Engineering FOAK Engineering Procurement Planning Site Specific Engineering Engineering ITAAC Fuel Load In Service Construction Site Preparation Plant Deployment 100% Plant Deployment Cumulative Expenditures Engineering COL 0% ESP /04-1

29 Conclusions Criteria for a successful ESP or COL Application To have a valid, accurate, adequate and representative meteorological data base is vitally important; Planning or selecting a data collection system, and conducting a thorough examination of the data by a professional meteorologist are highly recommended; and Close coordination and cooperation between the regulatory agency and permit applicants is highly desirable for the following reasons: Relevant guidance from both the NRC and industry is not comprehensive and precise; Issuance of R.G. 1.23, Rev. 1, DG-1145 and NUREG-0800, Rev. 3 is expected to be in the near future; and Applicants should be prepared to address the new and/or the revised regulatory guides. 29