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1 Evaluation of Historical Methods for Determination of Total Volumes Collected in RETS/REMP Air Monitoring Applications with Currently Available Technology.

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Presentation on theme: "1 Evaluation of Historical Methods for Determination of Total Volumes Collected in RETS/REMP Air Monitoring Applications with Currently Available Technology."— Presentation transcript:

1 1 Evaluation of Historical Methods for Determination of Total Volumes Collected in RETS/REMP Air Monitoring Applications with Currently Available Technology By Frank M. Gavila F&J SPECIALTY PRODUCTS, INC.

2 2 Basic Components Utilized in Traditional Air Monitoring Systems Vacuum Pump: Oilless carbon vane pump Vacuum Pump: Oilless carbon vane pump Flowmeter: Variable area rotometer Flowmeter: Variable area rotometer Flow Regulator: Constant flow regulator that automatically adjust for filter dust loading Flow Regulator: Constant flow regulator that automatically adjust for filter dust loading Elapsed Time Meter: Electromechanical or electronic timer Elapsed Time Meter: Electromechanical or electronic timer Volume Totalizer: Dry gas test meter Volume Totalizer: Dry gas test meter

3 3 Optional Features Employed in RETS/REMP Environmental Air Monitoring Systems Thermostatically controlled fans Thermostatically controlled fans GFCI protection GFCI protection Multiple receptacle strips Multiple receptacle strips Light fixtures Light fixtures Heat lamps Heat lamps Small heaters Small heaters External gooseneck External gooseneck Removable base plates where all components are mounted to facilitate exchange of components Removable base plates where all components are mounted to facilitate exchange of components

4 4 Traditional Environmental Air Monitoring System

5 5 Components of Current Technology Air Monitoring Systems Vacuum pump Vacuum pump Flow regulator Flow regulator All purpose microprocessor controlled electronic control center All purpose microprocessor controlled electronic control center One or more of the option listed below: One or more of the option listed below: 1. Thermostatically controlled fans 2. GFCI protection 3. Multiple receptacle strips 4. Light fixtures 5. Small heaters 6. External gooseneck 7. Removable base plates where all components are mounted to facilitate exchange of components

6 6 Features Provided by All Purpose Electronic Control Centers Digital display of data values utilizing LCD, LED, or VFD displays Digital display of data values utilizing LCD, LED, or VFD displays Accurate flow sensor Accurate flow sensor Very accurate elapsed time meter Very accurate elapsed time meter Very accurate determination of flowrate corrected to STP Very accurate determination of flowrate corrected to STP Very accurate volume totalization corrected to STP Very accurate volume totalization corrected to STP Measurement of air flow temperature Measurement of air flow temperature Absolute pressure measurement (usually at entry to flow sensor) Absolute pressure measurement (usually at entry to flow sensor) Auto shut-off on time, selectable by operator Auto shut-off on time, selectable by operator Auto shut-off on volume, selectable by operator Auto shut-off on volume, selectable by operator Data export capability through RS232 Data export capability through RS232 Data storage Data storage Programmability by operator of periodic sampling intervals Programmability by operator of periodic sampling intervals Data acquisition, data management and report software Data acquisition, data management and report software Capability for real time interaction with field instrument (some additional hardware required) Capability for real time interaction with field instrument (some additional hardware required)

7 7 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs CriteriaTraditional TechnologyCurrent Technology Flow Rate Maximum 5% at time of 2%-4% for long Accuracy reading. Easy to make term unattended errors reading rotometers. monitoring appli- No record of measured cation.Errors are flowrate.at a minimum in reading a digital display.Flow rate record of time is available.

8 8 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) CriteriaTraditional TechnologyCurrent Technology Volume Totalization Very poor; usually start plusExcellent; volume Accuracy without ending flowrate divided by 2 accumulation com- dry gas test metermultiplied by elapsed time puted as frequently that was recorded by timer or as once per second the time elapsed between of the or other acceptable two readings of the rotometer. frequency. These values are con- The value of flowrates in between tinually summed readings is not known and results giving up-to-date in unknown accuracy.volume accumulation on display and at the end of measurement.

9 9 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) CriteriaTraditional TechnologyCurrent Technology Volume TotalizationMarginal; the volumes measured Volumes collected accuracy with dry gas are actual volumes at the temper-can be compared to test meterature and pressure at which thevolumes collected gas flows through the meter at at any other NPP any point in time. Can’t compare location, regardless volumes at different plant sites of elevation differ- or at different times at the same ences, seasonal plant site. differences or short term climatic changes between sites.

10 10 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) Criteria Traditional TechnologyCurrent Technology Capability to correct None; if dry gas meter is used Excellent; systems volumes to a reference for volume totalizations; it does can be set to correct temperature and not correct for pressure changesincremental volumes pressure and unless it is a temperature to any reference compensated meter, it does not temperature and compensated meter, it does not temperature and correct for temperature changes. pressure or even to correct for temperature changes. pressure or even to Volumes reported are actual report actual volume, Volumes reported are actual report actual volume, volumes, which vary from day to if desired volumes, which vary from day to if desired night and season to season due night and season to season due to variations in pressure and to variations in pressure and temperature during the sampling temperature during the sampling period period

11 11 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) CriteriaTraditional TechnologyCurrent Technology Size requirementsDry gas test meter Typical footprint ~1540 cubic inchesrange is approxi- Elapsed time metermately cubic ~negligibleinches. Additional features implemented by software can be selected without increasing the footprint size.

12 12 Comparison of DGTM Volume Totalizer Dimensions With The Dimensions of Current Technology Systems

13 13 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) CriteriaTraditional TechnologyCurrent Technology CostLess expensive than top of theFully programmable, line electronic units. Comparable units are 70 to 100% in price to electronic units that greater in cost than offer basic features of flowrate traditional techno- and volume totalization, digital logy units. Middle of display and RS232 communicationthe line units are portcomparable in price when you consider the costs of air sampler + timer + dry gas test meter and fittings

14 14 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) CriteriaTraditional TechnologyCurrent Technology Calibration Calibration of individualEntire unit can be components is required. calibrated at one Calibration of components time as a single at different dates in not component. desirable.

15 15 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) CriteriaTraditional TechnologyCurrent Technology Maintenance Maintenance expertise for Single vendor various components required; involved provides different vendors involved.maintenance service or maintenance instructions.

16 16 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) CriteriaTraditional TechnologyCurrent Technology Legal/Data accuracy is less than Data record Regulatory desirable. No certainties of available to operating conditions determine the during unattended periods. operating conditions at any unattended period of time. Greater accuracy of values improves credibility with regulatory agencies and for use as evidence in legal proceedings.

17 17 Comparison of Traditional RETS/REMP Sampling System Designs with Current Technology Designs (cont.) CriteriaTraditional TechnologyCurrent Technology Calibration of dry gasCalibrations performed at pressureCalibrations per- Test meter conditions that do not bracket the formed for pressure operating pressure range exper- ranges applicable ience of most RETS/REMP to RETS/REMP applications.system operating conditions. Current technology systems can be calibrated easily over the ranges of absolute pressures that the monitoring system will be exposed to.

18 18 Comparison of Pressure Drop Differences for Different Filter Combinations at Two Different Flowrates FilterPressure DropPressure Drop LPM “H 2 O“ Hg“H 2 O“ Hg TE2C +FP TE3C+FP47M TE1C+FP47M AGZC58+FP u membrane* * Maximum flowrate achieved was 80 LPM

19 19 Physical Parameters that Influence the Absolute Pressure Value at DGTM Pressure drop is a function of the filter combination in use. More restrictive filter combinations create greater pressure drops. Pressure drop is a function of the filter combination in use. More restrictive filter combinations create greater pressure drops. Flowrate of sampling operation Flowrate of sampling operation Pressure drop is proportional to flowrate. Pressure drop is proportional to flowrate. Larger flowrates create larger pressure drops. Larger flowrates create larger pressure drops. Line losses throughout sampling systems upstream of DGTM. Line losses throughout sampling systems upstream of DGTM. Smaller sample line ID and longer flow paths upstream of DGTM increase pressure drop. Smaller sample line ID and longer flow paths upstream of DGTM increase pressure drop.

20 20 Physical Test Set-up for Comparing Volumes Determined by DGTM and Current Technology System

21 21 Dry Gas Test Meter Accumulated Volumes at Various Vacuum Conditions Corrected PressureFlowDGTMDGTMDGTMDGTM V DL-1 % B.P DropRateFinalInitialActual STP V Deviation (“ Hg) (“ Hg) (LPM) Filters ReadingReading(m 3 ) (m 3 ) (m 3 STP TE2C FP A080A047A TE2C CI CI47(2) AGZC58 Temperature Correction: None made because temperature compensated meter was utilized Pressure Correction:V STP – V A (B.P – Pressure Drop) V A = Actual volume 29.92” Hg V STP = STP 1 atm and 70 o F % STPV DGTM (STP )- V DL-1 (STP)X 100 V DGTM (STP)

22 22 Observations of Test Data and Issues related to DGTM Calibration Methodology Impact of difference in absolute pressure at DGTM and atmospheric pressure is greater than impact of difference in actual temperature and reference temperature at 70 o F. Utilization of temperature compensated DGTM eliminates differences due to temperature. Impact of difference in absolute pressure at DGTM and atmospheric pressure is greater than impact of difference in actual temperature and reference temperature at 70 o F. Utilization of temperature compensated DGTM eliminates differences due to temperature. Actual volumes collected at actual P below atmospheric pressure are always greater than volumes at a reference pressure of 1 atm. This is due to the fact that gases expand at the lower absolute pressure values such as those existing at the DGTM. Actual volumes collected at actual P below atmospheric pressure are always greater than volumes at a reference pressure of 1 atm. This is due to the fact that gases expand at the lower absolute pressure values such as those existing at the DGTM. DGTM volumes when corrected to STP utilizing known P conditions differ substantially from volumes collected by the instrument that corrects volumes to STP in increments of once per second. DGTM volumes when corrected to STP utilizing known P conditions differ substantially from volumes collected by the instrument that corrects volumes to STP in increments of once per second. WHY IS THIS? Typical Calibration Procedure for DGTM DGTM calibration performed utilizing very accurate Bell Prover at vacuum conditions DGTM calibration performed utilizing very accurate Bell Prover at vacuum conditions According to the Inversys calibration laboratory the maximum vacuum value below atmospheric pressure is 7” H 2 O at the maximum flow rate of DGTM utilized by F&J in tests performed to collect data for this paper. According to the Inversys calibration laboratory the maximum vacuum value below atmospheric pressure is 7” H 2 O at the maximum flow rate of DGTM utilized by F&J in tests performed to collect data for this paper.

23 23 Observations of Test Data and Issues related to DGTM Calibration Methodology (cont.) Observations Absolute pressure values at the DGTM for typical filter combination utilized in RETS/REMP monitoring very probably are not within the range at which the typical DGTM are calibrated even for the least restrictive filter combinations utilized this these programs. This can be alternatively stated that One or more types of DGTM utilized in NPP RETS/REMP monitoring applications may not be calibrated at pressure conditions at which they are being utilized to measure volumes and thus this field practice is inconsistent with standard scientific instrument measurement practices applicable to our industry.

24 24 Conclusions Organizations utilizing DGTM for volume totalizations in RETS/REMP monitoring applications should reexamine their programs. An evaluation of these issues could include one or more of the following items: Determination of typical absolute pressure values at the inlet to the DGTM for the actual systems employed at the plant sites. Determination of typical absolute pressure values at the inlet to the DGTM for the actual systems employed at the plant sites. Determination of calibration conditions for pressure utilized by the manufacturer of the DGTM utilized in the RETS/REMP system at maximum flow rate through the DGTM. Determination of calibration conditions for pressure utilized by the manufacturer of the DGTM utilized in the RETS/REMP system at maximum flow rate through the DGTM.

25 25 Conclusions (cont.) Evaluation of the probable errors in volume determination, obtained with use of the existing DGTM at the typical range of absolute pressures existing at each DGTM. Evaluation of the probable errors in volume determination, obtained with use of the existing DGTM at the typical range of absolute pressures existing at each DGTM. Installation of temperature compensated DGTM to limit the measurement issues to the absolute pressures existing at the DGTM. Installation of temperature compensated DGTM to limit the measurement issues to the absolute pressures existing at the DGTM. Determination as to whether use of DGTM at pressure conditions outside the range for which the instrument is calibrated is acceptable from a scientific and/or regulatory perspective. Determination as to whether use of DGTM at pressure conditions outside the range for which the instrument is calibrated is acceptable from a scientific and/or regulatory perspective. Report all volumes as actual volumes on data sheets and reports unless STP volumes are actually being determined. Report all volumes as actual volumes on data sheets and reports unless STP volumes are actually being determined.


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