ML19341D302

Forwards Revised Description of Onsite Meteorological Measurements Program.Revision Will Be Included in OL Application

ML19341D302
Person / Time
Site:	Yellow Creek
Issue date:	02/26/1981
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	Miraglia F Office of Nuclear Reactor Regulation
References
NUDOCS 8103050306
Download: ML19341D302 (14)

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i TENNESSEE VALLEY. AUTHORITY l CH ATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower II

February 26, 1981 Director of Nuclear Reactor Regulation Attentions Mr. F. M'mglia, Acting Chief Licensing Branch No. 3 Division ~of Licensing 4

U.S. Nuclear-Regulator:r Commission Nashington,.DC 2055C Dear Mr. Miraglia In the Natter of the Application of ) Docket Nos. STN 50-566 i Tennessee Valley Authority ) STN 50-567

< In Section 2 3 3 of the Preliminary Safety Analysis Report for Yellow Creek

Nuclear Plant, TVA provides a description of the prograen for-meteoro-logical measurements at the site. Enclosed for your information are seven j oopies of our revised description of the Onsite Meteorological Measurements Program. A similar revision has already been made for osch of the other TVA nuclear plant safety analysis reports. This revision has been designed-to standardize and minimize future revisions. This revision will be

) included in our application for an operating license for the Yellow Creek i Nuclear Plant.

Very truly yours, TENNESSEE VALLEY AUTHORITY i d L. M. Mills, Hanager Nuclear Regulation and Safety

! Sworn er subsor before me thim M day of, , 1981

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.NotaryPublio 6 ,

My Commission Expires Y f!b $ ,..

f < y - .:

O nG Enclosure (7) F co: Mr. James P._O'Reilly, Director (Enclosure) [y)

"2; Office of Inspection and Enforcement ,

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, U.S. Nuclear Regulatory Commission ~S

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, Region II - Suite 3100 $

j- 101 Marietta Street ,,;  ;

Atlanta, Georgia 30303

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903050 h b an cauai oppo,tumry anniave

e ENCLOSURE 2.3.3 Onsite iteteorological Measurement Program 2.3.3.1 Preoperational Program 2.3.3.1.1 Temporary !!cteorological Facility The temporary meteorological f acility for the proposed Yellow Creek Nuclear Plant consists of a 150-foot meteorological tower, sensors mounted on the tower, and a data collection system in an instrument trailer located near the tower. It is located in a large cicar area on the west side of the Yc.' low Creek embayment, at an elevation of approximately 154 meters (505 fcei) msl. The facility is about 2.2 km (7000 feet) west-southwest of t'.ie proposed location of the reactor c ntainment buildings (Figure 2.3-18 (T)) .

Data collection at the temporary facility began July 31, 1973, with measurements of wind speed, wind direction c d temperature at the 33- and 150-foot levels. A dewpoint sensor was installed at the 33-foot level on February 9, 1976. Because of instrumentation problems which were not resolved until late April 1976, collection of valid dewpoint data did not commence until April 23, 1976. Sensor specifications for the temporary acteorological f acility are given in the following subsection.

Detailed system accuracies are given in section 2.3.3.1.2 entitled, "Permar.ent Meteorological Facility."

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Instrument Description A description of the meteorological sensors follows. More. detailed scnner specifications are included in the station manual, which vill be updated as necessary (rather than the following linting) tu reficc t system sensor channes.

Replacement sensors, which may be of a dif f erent manuf ac turer or model, will meet or exceed the Regulatory Guide 1.23 specifications.

SENSOR DESCRIPTION llCIGitT(f ec t)

Wind Direction 33 and 150 Climet Instruments, Inc.,

Model 012-10;* threshold, 0.75 mph; accuracy, + 3 .

Wind Speed 33 and 150 Climet Instrument, Inc.,

Model 011-1;* threshold, 0.6 nph; accuracy, t 1%

or 0.15 mph, whicheect is

, gr'ater.

Temperaturc** 33 and 150 Weed Instrument Co..

Model 101;* accuracc,

+ 0.06 F; Climet instru-ments, Inc., Model n16-ta aspirated radiation shielo; crror, O F to 0.2 F.

Dewpoint 33 EC & G, Inc . , Model 440 accuracy, +f0.7 F.

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• A eplacement set R.G. 1.23 specifica of a dif ferent manufac turer or model will meet or exceed ms.

• • Temperature gradient (AT) measurements between 33- and 150 feet were made from July 25, 1974, through July 22, 1976, through use of a special bridge in a modified lionan Model 125 Trans ' tor. The aT and 33-foot temperatute data were used to calculate the 150-foot temperatutes.

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4 Data Collection and Processing System A Pulse-0-Matic (P-0-M) data logging system was used for logging and processing of the temporary facility data prior to July 22, 1976. The P-0-M system included the tower-mounted meteorological sensors, cables, signal translators, analog voltage-to-pulse converters, magnetic tape recorders, and backup strip-chart recorders. Outputs from all sensors were continuously recorded on the strip-chart recorders and the P-0-M magnetic tape recorders.

Offsite computer processing of the magnetic tape involved converting the pulse rate signals into digital one-minute mean values. Hourly values of wind speed and temperature were computed as the arithmetic means of the 60 one-minute values. Hourly values of prevailing wind direction were computed as the arithmetic means of the values within the 23-degree sector (among 360 overlapping sectors) which had the highest number of one-minute values during each hour.

When P-0-M data logging outages occurred, the available data on the backup analog strip charts (all parameters) were analyzed, processed, and integrated with the normal P-C M data to provide data records as continuous as practical.

A minicomputer (NOVA 1200 by Data General Corporation) has been used for logging and processing of the temporary facility data since July 22, 1976.

The data acquisition system with the NOVA is identical to that described in the " Data Acquisition System" subsection for the permanent meteorological facility. Systems other than the NOVA system for data processing may be used. These systems will meet or excced total system specifications identified in Regulatory Guide 1.23.

s Instrument Servicing, Maintena ce, and Calibration Operational checks of the temporary meteorological facility are made at least twice weekly, or more frequently as necessary, to achieve the required 90-percent recovery of data. The calibration schedule currently followed is identical to that described in the subsection entitled " Instrument Servicing, Maintenance and Calibration" for the permanent meteorological f acility.

Prior to July 22, 1976, meteorological' systems were calibrated monthly.

lInc of Rmporary Facility Data Data acquired during the period July 2, 1974, through June 30, 1975, have been utilized in this report. Anrual joint frequency distributions of wind direction and wind speed, by stability class (in accordance with RG 1.23) are presented in .1hbles 2.3-29(T) and 2.3-30(T) . For comparison purposes, Tables 2.3-31(T) and 2.3-32(T) provide stability-classified joint frequency distributions for Memphis for both the onsite period of record and for the period 1950-1954 inclusive. Statistics on data recovery during this period are presented in Tabic 2.3-33(T). Tabulations of the onsite hourly data are provided in Appendix 2.3A. These data have also been provided (separately) on magnetic tape to the NRC meteorology review staff.

2.3.3.1.2 Permanent Meteorological Facility The permanent meteorological facility consists of a 110-meter meteorological tower, sensors mounted on the tower, and a data collection system in an instrument trailer (Environnental Data Station) near th'c tower. The facility Tower and sensor heights at the permanent f acility are given in metric units as a result of the policy change to the metric system since the dnta analyses from the temporary facility were completed. i l

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is located at the ' center of a flat-topped hill on the cast side of the

! Yellow Crcck embayment, approximately 1 km (3,300 feet) northwest of the proposed' unit i reactor site. The base elevation of the permanent tower is 168 meters (550 feet) us1.

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J Terrain at the permanent site is relatively flat in the immediate vicinity of the tower (within.about 100 maters) and slopes off in all directions 4

beyond'about 100 meters'(330 feet). Average terrain slope in the. direction of the Yellow Creek embayment, which lies about 300 meters (1000 feet) southwest of the meteorological tower, is about 14 percent. .The average slopes in other directions (within about 300 meters) range between 5 and 10 percent. .The effects of these slopes on air. flow at the permanent

[ facility have been reduced by retention of existing vegetation. Clearing

. operations .have reduced the width of a strip of trees which acts as a buffer between the meteorological tower clearing and a cleared-slope to the cast. The extent of this clearing is not expected to have a i . recognizable ef fect on the data from the meteorological facility. A 1

4- detailed sketch and/or aerial photograph showing the topography and v2getation cover around the site, will be included in the station manual.

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Data collection at the permanent meteorological facility commenced on

" April 1, 1977. Meteorological sensors include tower-mounted sensors for i'; wind speed, wind direction and temperature at 10, 60, and 110 meters and for dewpoint temperature at 10 meters. Solar radiation and precipitation J

sensors are located approximately 25 meters from the tower at heights of 1

about 1 meter. An atmospheric pressure sensor is located in the

' Environmental Data Station (EDS), approximately 40 meters'from the tower.

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l Instrument Dencription

• A description of the meteorologi. cal sensors follows. More detailed sensor l

- specifications a rc included in the station manual, which yill be updated as I necessary (rather than the following listing) to reflec t system sensor changes.

Replacement sensors, which may be of a dif f erent ma nuf ac turer or model, will acet or exceed the Regulatory Guide 1.23 specifications.

SEUSOR  !!CICllT (meters) DESCRIPTION Wind Direction 10, 60 and 110 ,Climet Instruments, Inc. ,

Model 012-10;* threshold.

0.75 mph; accuracy, i 3 Wind Speed 10, 60 and 110 Climet Instrument, Inc.,

Model 011-1;* threshold, 0.6 mph; accuracy i 1%

or 0.15 mph, whichever !s greater.

Temperature ** 10, 60 and 110 Weed Instrument Co.,

Model 101.* accuracy, 1 0.06 F; Climet Instru-ments, Inc . , Model 016 aspirated radiation shiaM; error, O F to 0.2 F.*

Dcwpoint 10 EC & G, Inc., Momel 440'

• accuracy, 1 0.7 F.

Solar Radiation 1 Epplcy Laboratories, I t. ,

Model 3-46;* accuracy,

+ 2% .

Rainf all 1 Belfort Instrunent Co.

Model 5915-12;* accurac,,

1 0.06 inch.

Atmospheric Pressure 1 11. E . So s tma n a nd Co . ,

Model 2014-23/32 raL;*

accuracy, + 0.06 inch lig.

• A replacement sensor of a dif f erent manuf ac turer or model vill meet or exct ed RG 1.23 specifications.

• • Actual sensor heights are 10.0, 60.3 and 110.3 meters.

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o System Accuracies

. The system is designed so that the data meet or exceed the accuracy requirements of Regulatory Guide 1.23. More detailed information on total system and system component accuracies are given in the station manual, which will be updated as necessary (rather than the following discussion) to reflect system component and accuracy estimate changes. Replacement components will be compatible with the total system and will be chosen so that th'c to tal system accuracy will meet or exceed RG 1.23 specifications. .

Wind Speed Error Units: mph mph mph Component Wind Speed: 10 30 100 Sensor, j; l'.' of true j; 0.15 j; 0.30 j; 1.00 value or f; 0.15 mph, whichever is greater Translator, linear- 1 0.21 + 0.21 + 0.21 ity plus drift, to-tal error DVM, total error, 1 0.03 1 0.03 1 0.03 full scale Software, total 0 0 0 crror, full scalc Total maximum error 1 0.39 1 0.54 + 1.24 Root sum square error 1 0.26 1 0.37 i 1.02 RG 1.23 specification 1 0.5 1 0.5 + 0.5 The instantaneous root sum square crror f or wind speed measurements (which assumes individual component errors are additive and independent) is within the RG 1.23 specifications for all wind speeds less than 45 mph.

The error of time averaged wind speeds will be less than the instantaneous roo.

sum square error (this statement is applicabic for all other /

parameters in this discussion). Therefore, for wind speeds considered to be most critical for dia-persion calculations, the estimated error is well within the RG 1.23 specifi-cations.

• s Wind Direction Error

. Component Degrees

' Sensor -

1;3 DVM, total error, full scalc + 0.160 Software, total error, full scale - 0.674 Total maximum error - 3.834 Root sum square error + 3.08 BG 1.23 specification

+ 5.0 Dry-Bulb Tenocraturc Error .

Component 2 Sensor, RTD

+ 0.06 DVM, total error' + 0.08 Radiation error, maximum + 0.20 Software, total error

- 10*F - 0.35 50*F 0.00

- 110*F - 0.26 Total maximum error

- 10*F - 0.49 l 50*F - ,

+ 0.34 110*F - 0.40 Root sum squarc error

- 10*F + 0.42 50*F 8 +

_.0.22 110*F + 0.34

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RG 1.23 specificatior ,

+ 0. 9 (+ 0. 5 *C) t

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Vertical Terperature Difference Error j l

Component 2 Sensor 1 j; 0.06 Sensor 2 j;0.06 DVM (Sensor 1 reading) j; 0.08 DVrt (Sensor 2 reading) + f.08 Radiation 0.0 Software 0.0 Total maximum error j; 0.28 -

Root sum squarc error j; 0.14 RG 1.23 specification j; 0.18 (+ 0. l*C)

The assumption is cade that the radistica and software errors arc identimal for both sensors and therefore cancel.

Deepoint Ter.perature Error Component 2 Sensor EG & G Model 440 j; 0.7 Mirror contamination + 0.3 Loss of water in sample lines - 0.2 Sample line contamination j; 0.1 Pressure change . correction j; 0.1 Frost point conversion (dewpoints j;0.05 below 32*F)

DVM, total error, full scalc + 0.04 h Software, total error 0.0 Total maximum error + 1.29 Root sum square error j;0.80 RG 1.23 specificatica j; 0.90 (+ 0.5*C)

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Data Acquisition Systen i l

The data acquisition system is located at the EDS and consists of the  !

sensors mounted on the tower, cables, signal translators, reed-relay scanner, DVM (analog voltage and ohms to digital converter) and minicomputer (NOVA 1200 by Data General Corporation). All meteorological sensor outputs are measured periodically during each hour by the data system for an hourly readout on the teletype. Horizontal wind direction is read each five seconds (720 per hour); wind . speed and solar radiation are read each 15 seconds (240 per hour); temperature and dewpoint are read cach minute (60 per hour); and rainf all and atmospheric pressure are read each hour (onc per hour) . Strip-chart recorders are also used to record wind speed and wind direction data.

Prevailing horizontal wind direction fnr each hour is corputed as the average direction in the 23-degree sector (among 360 overlapping sectors) that has the highest number of valid readings during the hour. Horizontal wind direction persistence percentage for a given hour is computed as the number of readings in the 23-degree sector divided by the total number of valid readings obtained in that one-hour period multiplied by 100.

Systems other than the MOVA system for data processing may be used. These systems will meet or exceed total system specifications identified in Regulatory Guide 1.23.

Data Recording and Display Data recording and display at the EDS consists of hourly teletypewriter printouts (ASR 33) and punched paper tapes. Strip chart backup recording is provided for wind direction and wind speed to assure, as nearly as

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possible, continuous data collection. The data collected on the paper tapes are transferred of fsite for processing onto magnetic tapes for storage and for use in analysis of onsite meteorological conditions.

. Selected meteorological data, along with other environmental data, will be remoted f rom the acteorological f acility for operational display in the reactor control room. The meteorological data will include 10 , 60 , and 110-meter wind speed and wind direction and 10- to 60-meter and.10- to 110-meter temperature dif ferences. Action is being taken to provide these data in digital form with at least 15-minute updating. Meteorological data from the EDS will also be telemetered to the TVA Meteorological Forecast Center in Muscle Shoals, Alabama, for use in support of the radiological emergency plan.

Instrument Servicing, Maintenance and Calibration The permanent meteorological f acility is serviced by engineering aides, instrument technicians, or engineers. Maintenance and calibrations are performed by instrument technicians, electrical engineering associates, or electrical engineers. Prior to plant operation, operational checks of the system performance are made twice weekly, or more f requently as necessary to achieve the required 90 percent recovery of data. The calibration status of each component of the meteorological facility (sensors, recorders, electronics, DVM, data logger, etc.), is checked and/or field calibrated and/or removed and replaced by a laboratory calibrated component, at least every six months. More, frequent calibration intervals for individual components may be specified in the station manual, on the basis of the operational history of that component' type, in order to ensure the maximum practicable recovery rate. Detailed, standardized l

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, ;. : ea r e procedures are included in the station' manual and/or the laboratory

. calibration procedures document.

l 2.3.3.2 Operational Program.

t-Compariso,n of Temporary and Permanent Data ,

A study based on comparisons of meteorological data-from the temporary and' permanent meteorological facilitics was completed in response to hRC minireview request 372.08 and round one- question 372.32. The purpose'of

.t hL e stu dy was to identify any potentially_si,gnificant differences in the meteorological characteristics of the two sites _ and to assess the relative suitability of the meteorologicai data from the two sites for use in cvaluating site and regional dispersion characteristics. Conclusions of the comparison, which was based on four months of' concurrent data (April 1, 1977 through July 31, 1977) were: (1) that the meteorological data from the permanent f acility better represent airflow at potential ef fluent release points, and therefore, provide a more representative basis for evaluating site and regional dispersion characteristics and (2) that the X/Q's based on the temporary facility data are more conservative (higher) than those based on permanent facility data. Judgments, based on temporary.

tower X/Q's, and initially presented in the PSAR, are considered to be unchanged as a result of these comparisons. The full text of the TVA response tn question 372.32 has been included in amendment 12 to the PSAR.

' Operational Measurements The operational phase of the meteorological program includes those procedures

, i and responsibilitics related to activitics beginning with the initial fuel loading and continuing through the life of the plant. The meteorological l

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data collection program will be continuous without major interruptions.

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. Operational system checks on the meteorological facility will be ma'de

- daily Monday through Friday and as necessary on weekends and holidays

'(if there are storms, power system disturbances, etc.). The' meteorological program has been developed to conform to' the standards given in NRC Regulatory Guide 1.23 and the reporting procedures in Regulatory Guide 1.21. The basic objective is to maintain a continuous surveillance- (by digital or analog record) of the mctcorological parameters involved in the.

atmospheric dispersion of radioactive effluent releases, and to have the data available at any time for assessing the relative concentrations and doses resulting from accidental or routine releases. Meteorological

! data .will also be displayed in the reactor control room ar.d at the TVA Meteorological Forecast Center in Muscle Shoals, Alabama as discussed in the " Data Recording and Display" subsection.

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The restoration of the data collection in the event of equipment failure 1

l or malfunction will be accomplished by prompt replacement or repair of i

f affected equipment. A stock of spare parts and equipment is maintained at the environmental data station to minimize and shorten ' the periods of ou t age:.. Equi pr.ien t malfunctions or outages are detected by field personnel during routine or special checks.

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