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OL - FW: 10-21-10_WBN U2 FSAR Section 2.3_NRC Copy 1 of 4.pdf
	ML103140664
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Site:	Watts Bar
Issue date:	10/21/2010
From:	; Office of Nuclear Reactor Regulation
To:	; Division of Operating Reactor Licensing
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WBN2Public Resource From: Poole, Justin Sent: Thursday, October 21, 2010 4:29 PM To: Brown, Leta Cc: WBN2HearingFile Resource

Subject:

FW: 10-21-10_WBN U2 FSAR Section 2.3_NRC Copy 1 of 4.pdf Attachments: 10-21-10_WBN U2 FSAR Section 2.3_NRC Copy 1 of 4.pdf

Leta, Here is your section of the FSAR as it will appear in Amendment 101. This letter will be on the docket so you dont need to wait for the actual Amendment 101 to arrive. Note - due to the file size there are 4 emails which make up the entire document.

Justin C. Poole Project Manager NRR/DORL/LPWB U.S. Nuclear Regulatory Commission (301)4152048 email: Justin.Poole@nrc.gov From: Boyd, Desiree L [1]

Sent: Thursday, October 21, 2010 4:13 PM To: Wiebe, Joel; Poole, Justin; Raghavan, Rags; Milano, Patrick; Campbell, Stephen Cc: Crouch, William D

Subject:

10-21-10_WBN U2 FSAR Section 2.3_NRC Copy 1 of 4.pdf Please see attached letter that was mailed to the NRC today.

I have broken this large file up into 4.

1 of 4 - FSAR Section 2.3

~*~*~*~*~*~*~*~*~*~*~*~*~*~*~

Désireé L. Boyd WBN 2 Licensing Support Sun Technical Services dlboyd@tva.gov 4233658764

~*~*~*~*~*~*~*~*~*~*~*~*~*~*~

1

Hearing Identifier: Watts_Bar_2_Operating_LA_Public Email Number: 179 Mail Envelope Properties (19D990B45D535548840D1118C451C74D6FD3723A07)

Subject:

FW: 10-21-10_WBN U2 FSAR Section 2.3_NRC Copy 1 of 4.pdf Sent Date: 10/21/2010 4:28:39 PM Received Date: 10/21/2010 4:28:45 PM From: Poole, Justin Created By: Justin.Poole@nrc.gov Recipients:

"WBN2HearingFile Resource" <WBN2HearingFile.Resource@nrc.gov>

Tracking Status: None "Brown, Leta" <Leta.Brown@nrc.gov>

Tracking Status: None Post Office: HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 1077 10/21/2010 4:28:45 PM 10-21-10_WBN U2 FSAR Section 2.3_NRC Copy 1 of 4.pdf 3402613 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 October 21, 2010 10 CFR 50.4 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 2 Docket No. 50-391

Subject:

WATTS BAR NUCLEAR PLANT (WBN) - UNIT 2 - FINAL SAFETY ANALYSIS REPORT (FSAR), SECTION 2.3

References:

1. TVA letter to NRC dated August 30, 2010, Watts Bar Nuclear Plant (WBN) Unit 2 - Final Safety Analysis Report (FSAR) - Response to Requests for Additional Information

2. TVA letter to the NRC dated September 1, 2010, Watts Bar Nuclear Plant (WBN) - Unit 2 - Final Safety Analysis Report Amendment 100

3. TVA letter to NRC dated October 4, 2010, Watts Bar Nuclear Plant (WBN) Unit 2 - Final Safety Analysis Report (FSAR) - Response to Requests for Additional Information The purpose of this letter is to provide FSAR Section 2.3, Meteorology, in advance of FSAR, Amendment 101 being submitted in order to facilitate an NRC review request.

Changes to Section 2.3 are a result of previous NRC Requests for Additional Information (RAIs) with the responses to those RAIs provided in References 1 and 3. The attached advance FSAR Section 2.3 will be submitted as part of the FSAR Amendment 101. contains the text, tables, and figures for Section 2.3. Enclosure 2 provides the list of commitments made in this letter.

U.S. Nuclear Regulatory Commission Page 3 October 21, 2010 cc (Enclosures)

U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Resident Inspector Unit 2 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381

U.S. Nuclear Regulatory Commission Page 4 October 21, 2010 bcc (Enclosures):

Stephen Campbell U.S. Nuclear Regulatory Commission MS 08H4A One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 Loren R. Plisco, Deputy Regional Administrator for Construction U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257

ENCLOSURE 1 WBN Unit 2 FSAR Section 2.3, Meteorology E1-1

WATTS BAR WBNP-101 2.3 METEOROLOGY 2.3.1 Regional Climate 2.3.1.1 Data Sources Most of the climatic data summaries and other publications used in describing the site region meteorology are included in the list of references for Section 2.3. Those used in a general way not specifically referenced are the following: (1) U.S. Department of Commerce, Normal Weather Charts for the Northern Hemisphere, U. S. Weather Bureau, Technical Paper No. 21, October 1952, and (2) U.S. Department of Commerce, Climatic Atlas of the United States, Environmental Science Services Administration, Environmental Data Service, June 1968.

2.3.1.2 General Climate The Watts Bar site is in the eastern Tennessee portion of the southern Appalachian region. This area is dominated much of the year by the Azores-Bermuda anticyclonic circulation shown in the annual normal sea level pressure distribution (Figure 2.3-1).[1]

This dominance is most pronounced in late summer and early fall and is accompanied by extended periods of fair weather and widespread atmospheric stagnation. [2] In winter and early spring, the normal circulation becomes diffuse over the region as eastward moving migratory high- or low-pressure systems, identified with the mid-latitude westerly upper air circulation, bring alternately cold and warm air masses into the Watts Bar site area with resultant changes in wind, atmospheric stability, precipitation, and other meteorological elements. In the summer and early fall, the migratory systems are less frequent and less intense. Frequent incursions of warm, moist air from the Gulf of Mexico and occasionally from the Atlantic Ocean are experienced in the summer.

The site is primarily influenced by cyclones from the Southwest and Gulf Coast that translate toward the Northeast U.S. Coast by passing along either the west side or the east side of the Appalachian chain and by cyclones from the Plains or Midwest that move up the Ohio Valley. Topography around the site strongly influences the local climate. Mountain ranges located both northwest and southeast of the site, which is in the upper Tennessee River Valley, are oriented generally northeast-southwest and rise 3,000 to 4,000 feet MSL and, in places, 5,000 to 6,000 feet MSL. The latter elevations are in the Great Smoky Mountains to the east and southeast. They provide an orographic barrier that reduces the low-level atmospheric moisture from the Atlantic Ocean brought into the area by winds from the East. However, considerable low-level atmospheric moisture from the Gulf of Mexico is often brought into the area by winds from the south, southwest, or west.

The predominant air masses affecting the site area may be described as interchangeably continental and maritime in the winter and spring, maritime in the summer, and continental in the fall. Temperature patterns generally conform to the seasonal trends typical of continental, humid subtropical climates. Precipitation is normally well distributed throughout the year, but monthly amounts are generally METEOROLOGY 2.3-1

WATTS BAR WBNP-101 largest in the winter and early spring and smallest in the late summer and fall. The primary maximum occurs in March and is associated with cyclones passing through or near the region. A secondary maximum of precipitation occurs in July and is characteristically the result of diurnal thunderstorms occurring most frequently in the afternoon and evening. The minimum monthly precipitation normally occurs in October. Snow and sleet usually occur only during the period November through March and generally result from cold air pushing southward through the area against relatively warm, moist air.

2.3.1.3 Severe Weather Severe storms are relatively infrequent in east Tennessee, being east of the area of major tornadic activity, south of nearly all storms producing blizzard conditions, and too far inland to be affected often by the remnants of intense tropical cyclones. Damage from such remnants of tropical cyclones is rare, occurring only about once every 18 years, and is generally restricted to flood effects from heavy rains.[3]

The probability that a tornado will strike the Watts Bar site is low. During the period 1950-2009 (when climatological records are fairly complete) there were 38 tornadoes within 30 miles of the Watts Bar site, including 12 tornadoes F3/EF3 or greater [aa,bb].

The probability of a tornado striking the site can be calculated using the following equations according to NUREG/CR-4461, Rev. 2 [cc]. Using the principle of geometric probability described by H. C. S. Thom, [8] the probability of a tornado striking any point in the one degree latitude by one degree longitude square containing the plant site may be calculated. Thom's equations are the following:

zt P = ----- (1)

A 1

R = ---- (2)

P P = mean probability of a tornado striking a point in any year in a one-degree square.

Z = mean path area of a tornado (mi2) t = mean number of tornadoes per year.

A = area of one-degree latitude, one-degree longitude square = 3887 mi2 for the one-degree square containing the Watts Bar site (84°W to 85°W by 35°N to 36°N).

R = mean recurrence interval for a tornado striking a point in the one- degree square (years).

2.3-2 METEOROLOGY

WATTS BAR WBNP-101 For z = 2.8209 mi2 (from H. C. S. Thom [8]) and t = 1.02 tornadoes per year (55 tornadoes from NUREG/CR-4461 divided by 54 years of record), the probability is 7.40 x 10-4 with a recurrence interval of 1351 years. For consideration in station blackout criteria, the annual expectation of tornadoes with winds exceeding 113 mph (F2/EF2 or greater) is 3.77 x 10-4 per square mile (t = 0.52, based on 28 tornadoes F2 and above 54 years).

Windstorms are relatively infrequent, but may occur several times a year. Strong winds are usually associated with thunderstorms that occur about 50 times per year based on records for Chattanooga and Knoxville (Table 2.3-1). Moderate and occasionally strong winds sometimes accompany migrating cyclones and air mass fronts. Wind records for Chattanooga exist for 1945-2009 (65 years)[dd], for Knoxville during 1943-2009 (67 years)[ee], and for Watts Bar meteorological tower during 1973-2009 (37 years). The extreme wind speed cases have been converted to 3-second gust equivalents for comparison (Table 2.3-1A). The highest observed wind speeds (3-second equivalent) are 102 mph on March 24, 1947 at Chattanooga, 88 mph on July 15, 1961 at Knoxville, and 59 mph on March 25, 1975 at Watts Bar meteorological tower. During 1950-2009, winds > 50 knots (> 57 mph) were reported an average of 16.33 times per year for Rhea County (which contains Watts Bar Nuclear Plant) and the 6 surrounding counties[ff] combined (Table 2.3-1B).

During 1950-2009, hail 3/4 inch in diameter or larger has been reported an average of 6.98 times per year for Rhea County and the 6 surrounding counties[ff] combined (Table 2.3-1B).The likelihood of hail (any size) for a specific location in the area is less than once per year, based on a 52-year record (1879-1930) at Chattanooga and a 60-year record (1871-1930) at Knoxville. [gg]

Annual lightning strike density is estimated to be 7.7 flashes to ground per km2 according to NUREG/CR-3759 [hh]. Based on thunderstorm day frequencies observed at Chattanooga (Table 2.3-1) the seasonal densities of flashes to ground per km2 are estimated to be 0.55 (winter), 2.17 (spring), 4.02 (summer), and 0.96 (fall). These seasonal densities were estimated by calculating the percent of the annual thunderstorm days during the season and multiplying by the annual lightning density value. For example, winter has 3.9 thunderstorm days out of the 55.1 annual total, or 7.1%. Applying 7.1% to the 7.7 annual flashes values results in the 0.55 seasonal flashes value for the winter season.

Relative potential for air pollution is indicated by the seasonal distribution of atmospheric stagnation cases of four days or more analyzed by Korshover.[15]In a 35-year period (1936-1970), there were about one case in the winter, 11 cases in the spring, 24 cases in the summer, and 34 cases in the fall. According to Holzworth [16]

there were about 35 forecast-days of high meteorological potential for air pollution in a 5-year period based on data collected in the 1960s and early 1970 (Figure 2.3-2). On the average, about seven air pollution forecast-days per year can be expected, with significantly greater probability in the summer and fall than in the winter and spring.

Frost penetration depth is important for protection of water lines and other buried structural features that are subject to freeze damage. The average depth for the 1899 METEOROLOGY 2.3-3

WATTS BAR WBNP-101 through 1938 period was about six inches, and the extreme depth during the 1909 through 1939 period was about 14 inches.[17]

Estimations of regional glaze probabilities have been made by Tattelman, et al. [18] For Region V, which contains Tennessee, point probabilities for glaze icing 5.0 cm or more thick and 2.5 cm or more thick in any one year are about 1.0 x 10-4 and 4.0 x 10-4, respectively. These probabilities correspond to recurrences of about once in 10,000 years and about once in 2,500 years. Ice thicknesses of 2.0, 1.8, 1.7, and 1.5 cm correspond to return periods of 100, 50, 25, and 10 years.

All ice storms with glaze thicknesses 2.5 cm or greater that were analyzed were accompanied by maximum wind gusts 10 m/sec or greater. However, only one had maximum gusts 20 m/sec or greater, and that storm had ice thicknesses less than 5.0 cm.

The point probabilities for lesser ice thicknesses are about 0.20 for > 1.25 cm and 0.37 for > 0.63 cm, and the respective recurrence intervals are once in five years and once in three years. However, glaze ice thicknesses 1.25 cm or less generally result in little structural damage, except for above-ground utility wires when strong winds are combined with the storms. The major impact of storms which produce these lesser ice thicknesses is a hazard to travel in the affected areas.

Snowfall records for Chattanooga NWS (1937-2009) show maximum 24-hour and monthly snowfall amounts of 20.0 and 20.0 inches [dd]. Snowfall records for Knoxville NWS (1951-2009) show maximum 24-hour and monthly snowfall amounts of 18.2 and 23.3 inches [ee]. Older records for Knoxville before the NWS station was established show a maximum single storm of 22.5 inches [19]. The total snow load was calculated by assuming that the maximum single snowfall falls on the maximum snowpack. For the Watts Bar Site area, the weight of the 100-year return period snow pack is estimated to be about 14 pounds per square foot.[20]Assuming that the 22.5 inches of snow that fell at Knoxville on December 4-6, 1886, had the water equivalency ratio of 1:7, or 0.14 inch per inch of snow, the weight would be about 17 pounds per square foot. The combined weight of the existing snowpack, plus the new snow would be about 31 pounds per square foot on a flat surface. For conservatism, the weight of the maximum single storm snowfall recorded in Tennessee during the 1871 through 1970 period was estimated. This 28-inch snowfall occurred on February 19-21, 1960 at Westbourne, on the Cumberland Plateau in northeastern Tennessee.[21] A more conservative water equivalency ratio of 1:6 was used to give an estimated weight of about 24 pounds per square foot. The total snow load for this case would be about 38 pounds per square foot. Design loading considerations, including the snow load, for the reactor shield building and other Category I structures are presented in Sections 3.8.1 and 3.8.4, respectively.

No meteorological parameters were used in evaluating the performance of the ultimate heat sink, which consists of a once-through cooling system utilizing the Chickamauga Reservoir on the Tennessee River. A demonstration of adequate water flow past the site is used in the design bases. This is discussed in Section 2.4.11.

2.3-4 METEOROLOGY

WATTS BAR WBNP-101 The initial design conditions assumed for the Watts Bar Nuclear Plant reactor shield building (and other safety-related structures) are the following:

(1) 300 mph = Rotational Speed (2) 60 mph = Translational Speed (3) 360 mph = Maximum Wind Speed (4) 3 psi = Pressure Drop (5) 1psi/sec = Rate of Pressure Drop (3 psi/3 sec is assumed)

For the additional Diesel Generator Building and structures initiated after July 1979, the design basis tornado parameters are as follows:

(1) 290 mph = Rotational Speed (2) 70 mph = Translational Speed (3) 360 mph = Maximum Wind Speed (4) 3 psi = Pressure Drop (5) 2 psi/sec = Rate of Pressure Drop (3 psi/1.5 sec is assumed)

These requirements have been recently updated by NRC. As defined in Regulatory Guide-1.76 (revision 1), the site is located on Region I for Design Basis Tornado considerations [ii]. The design conditions assumed for the Watts Bar Nuclear Plant reactor shield building (and other safety-related structures) are the following:

(1) 184 mph = Rotational Speed (2) 46 mph = Translational Speed (3) 230 mph = Maximum Wind Speed (4) 1.2 psi = Pressure Drop (5) 0.5 psi/sec = Rate of Pressure Drop (1.2 psi/2.4 sec is assumed)

These and tornado-driven missile criteria are discussed in Sections 3.3 and 3.5. The fastest mile of wind at 30 feet above ground is about 95 mph for a 100-year return period in the site area.[22] The vertical distribution of horizontal wind speeds at 50, 100, and 150 feet above ground is 102, 113, and 120 mph on the basis of the speed at 30 feet and a power law exponent of 1/7. A gust factor of 1.3 is often used at the 30-foot level, but this would be conservative for higher levels. The wind load for the Shield Building is based on 95 mph for that level, as discussed in Section 3.3. Estimates of the probable maximum precipitation (PMP) and the design considerations for the PMP are discussed in Section 2.4.

METEOROLOGY 2.3-5

WATTS BAR WBNP-101 2.3.2 Local Meteorology 2.3.2.1 Data Sources Short-term site-specific meteorological data from the TVA meteorological facility at the Watts Bar Nuclear Plant site are the basis for dispersion meteorology analysis. Data representative of the site or indicative of site conditions for temperature, precipitation, snowfall, humidity, fog, or wind were also obtained from climatological records for Chattanooga, Dayton, Decatur, Knoxville, Oak Ridge, and Watts Bar Dam, all in Tennessee. Short-term records for the Sequoyah Nuclear Plant site were used.

These data source locations are shown relative to the plant site in Figure 2.3-3.

2.3.2.2 Normal and Extreme Values of Meteorological Parameters Temperature data from Dayton [13] and Chattanooga[dd] are presented in Tables 2.3-2 and 2.3-3, respectively. The Chattanooga and Dayton mean daily data are provided as reasonably representative and recent (1971-2000) temperature information.

Normal mean dry-bulb temperatures range from 36.2-39.4°F in the winter to 76.9-79.6°F in the summer. Normal daily maximum temperatures range from 45.9-48.8°F in winter to 87.7-89.8°F in summer. Normal daily minimum temperatures range from 26.5-29.9°F in winter to 66.1-69.4°F in summer. The extreme maxima recorded for the respective data periods (46 years for Dayton and 70 years for Chattanooga) were 107°F at Dayton and 106°F at Chattanooga, while the extreme minima recorded were

-15°F and -10°F, respectively. Temperature data from Decatur (Table 2.3.2), for 60 years prior to data collection at Dayton, reported an extreme maximum temperature of 108°F and an extreme minimum temperature of -20°F.

Precipitation data are presented in Table 2.3-4. These data are from two different rain gauges near Watts Bar Nuclear Plant, one at Watts Bar Dam (1939-1975) and one at the Watts Bar Nuclear Plant meteorological tower (1974-2008). Precipitation has fallen an average of 110-111 days per year, with an annual average of 45.43 inches at the meteorological tower and 52.57 inches at Watts Bar Dam. The maximum monthly rainfall ranged from 6.52 inches to 14.78 inches. The minimum monthly amount was 0,00. The maximum rainfall in 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months was 5.31 inches at Watts Bar Dam in January 1946. The maximum in 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months at the meteorological tower was 4.77 inches on January 17, 1994. Mean monthly data reveal the wettest period as late fall through early spring, with March normally the wettest month of the year. Thunderstorm activity is most predominant in the spring and summer seasons, and the maximum frequency of thunderstorm days (Table 2.3-1) is normally in July.

Appreciable snowfall is relatively infrequent in the area. Snowfall data are summarized in Table 2.3-5 for Dayton[13] and in Table 2.3-6 for Chattanooga[dd] and Knoxville.[ee]

The Dayton, Chattanooga and Knoxville records provide current information and offer a complete picture of the pattern of snowfall in the Tennessee River Valley from Chattanooga to Knoxville. Mean annual snowfall has ranged from 4.4 inches at Dayton to about 10 inches at Knoxville. Dayton, about halfway between those locations, averaged about 4 inches annually for an earlier period of record. Generally, significant snowfalls are limited to November through March. For the data periods presented in the tables, respective 24-hour maximum snowfalls have been 20.0, 8.0, and 18.2 2.3-6 METEOROLOGY

WATTS BAR WBNP-101 inches at Chattanooga, Dayton, and Knoxville. Severe ice storms of freezing rain (or glaze) are infrequent, as discussed in the regional climatology section.

Atmospheric water vapor content is generally rather high in the site area, as was indicated in the discussion of the regional climatology. Long-term relative humidity and absolute humidity data for Chattanooga are presented in Tables 2.3-7 through 2.3-9.[dd,25] The relative humidity for selected hours in Table 2.3-7 has been updated to a more current period of record. Tables 2.3-8 and 2.3-9 cannot be easily updated, but are still valid since the information in Table 2.3-7 show no major changes in humidity characteristics. Humidity data based on measurements at the onsite meteorological facility are summarized in Tables 2.3-10 and 2.3-11 for comparison with the data in Tables 2.3-8 and 2.3-9. A typical diurnal variation is apparent in Table 2.3-7. Relative humidity and absolute humidity are normally greatest in the summer.

Fog data for Chattanooga,[dd] Knoxville,[ee] and Oak Ridge,[26] Tennessee, and from Hardwick [27] are presented in Table 2.3-12. These data indicate that heavy fog at the Watts Bar site likely occurs on about 35 days per year with the fall normally the foggiest season. Sources of data on fogs with visibilities significantly less than 1/4 mile and on durations of fogs which can be considered representative of the site have not been identified.

Wind direction patterns are strongly influenced by the northeast-southwest orientation of the major topographic features, as evidenced in the onsite data, Sequoyah Nuclear Plant data[28], and the records for Knoxville[ee] and Oak Ridge.[26] The Watts Bar wind direction and wind speed data are summarized in Tables 2.3-13 and 2.3-14 (annual at 10 and 46 meters); Tables 2.3-15 and 2.3-16 (directional persistence at 10 and 46 meters); and Tables 2.3-17 through 2.3-40 (monthly at 10 and 46 meters). The annual wind roses for each level are shown in Figures 2.3-4 and 2.3-5.

The most frequent wind direction at 10 meters has been from south-southwest (about 16%). The next highest frequencies (about 8%) are from the north-northeast and northwest wind. The data in Table 2.3-41 and the data in Table 2.3-13 show a predominance of wind from the north-northwest and northwest, respectively, for wind speeds less than about 3.5 mph. More discussion of this very light wind speed pattern is contained in Section 2.3.3.3. It is very significant that the frequencies of calms differ so markedly between the two sets of onsite data. It appears that the higher frequency of calm conditions is primarily a consequence of the location of the temporary meteorological facility in a "sink." The maximum wind direction persistence period at 10 meters is shown in Table 2.3-15 as 44 hours5.092593e-4 days 0.0122 hours 7.275132e-5 weeks 1.6742e-5 months from the south-southwest direction.

The monthly summaries show some minor variation in the wind direction patterns, but the upvalley-downvalley primary and secondary frequency maxima generally are fully evident.

In the summary tables for 46 meters, the upvalley-downvalley wind direction pattern is very clear and dominant. The two highest frequencies are 19% from the south-southwest wind direction and 11% from the north-northeast wind direction. The maximum wind direction persistence (Table 2.3-16) during the 17-year period was 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months from the south-southwest.

METEOROLOGY 2.3-7

WATTS BAR WBNP-101 Wind speed is normally lower than for most parts of the United States. The other data sources referenced in the discussion of wind direction patterns also reflect this condition. Annually, the onsite data show about 53% of the hourly average wind speeds at 10 meters were less than 3.5 mph and about 85% were less than 7.5 mph.

At 46 meters, the respective frequencies show the wind speeds are relatively lighter in summer and early fall and relatively stronger in late fall, winter, and spring.

Mean mixing height data for the United States have been researched by Holzworth.[16]

However, his analysis has utilized data to estimate morning mixing heights (after sunrise) and mid afternoon mixing heights. Night-time mixing heights are not addressed. Average daily mixing heights are likely to be reasonably similar to the mean morning mixing heights. The seasonal and annual estimates of these mixing heights are the following: winter, about 500 meters; spring, about 530 meters; summer, about 430 meters; fall, about 350 meters; and annual, about 450 meters.

Low-level inversion frequencies in the eastern Tennessee area have been studied by Hosler.[29] His seasonal frequencies indicate inversions in the Watts Bar area about 40% of the time in winter, 30% in spring, 45% in summer, and 45% in fall. The annual frequency is about 40%. The monthly and annual percent frequencies of hours with inversions measured at the Watts Bar onsite meteorological facility for the 20-year period, 1974 through 1993, are presented in Table 2.3-42. In comparison to Hosler's seasonal and annual values, the winter, summer, and fall values are slightly lower and the spring value is higher and has the greatest departure. The highest monthly frequency in Table 2.3-42 is about 44% in October and the lowest is about 30% in January, with an annual average of about 39%. Monthly and annual frequencies of Pasquill stability classes A-G are also presented in the same table and indicate that the most stable time of year is the fall. Korshover's statistics on atmospheric stagnation cases[15] discussed under "General Climate," provide the same indication.

Table 2.3-44 presents a summary of onsite inversion persistence data, with a breakdown by stability class, for the same 20-year period discussed above.

Persistence in this case is defined as two or more consecutive hours with vertical temperature gradient (T) values > 0 degrees Celsius. However, the individual classes are allowed one-hour departures among themselves. The data analyzed correspond to the T interval between 10 and 46 meters above the ground. The longest periods of inversion were 45 hours5.208333e-4 days 0.0125 hours 7.440476e-5 weeks 1.71225e-5 months in January 1982 and 42 hours4.861111e-4 days 0.0117 hours 6.944444e-5 weeks 1.5981e-5 months in December 1989. Other long periods, up to 21 hours2.430556e-4 days 0.00583 hours 3.472222e-5 weeks 7.9905e-6 months , occurred in winter. A combination of cold, dry air masses with the shorter length of the solar day in that half of the year and fresh snow on the ground surface can increase the probability for inversion durations greater than 14 hours1.62037e-4 days 0.00389 hours 2.314815e-5 weeks 5.327e-6 months in that time of year. The unusual case of 45 hours5.208333e-4 days 0.0125 hours 7.440476e-5 weeks 1.71225e-5 months of inversion persistence at this site occurred from January 19 to 21, 1982 at the end of a 10-day period of very cold weather. Persistent fog and low overcast with a synoptic pattern of warm air advection above an initially frozen, snow-covered ground surface and very light, variable winds at the 10-meter level created this condition.[30,31,32] The unusual case of 42 hours4.861111e-4 days 0.0117 hours 6.944444e-5 weeks 1.5981e-5 months of inversion persistence occurred from December 29-31, 1989 during a period in which a cold front stalled to the west of the site. All of Eastern Tennessee (including the Watts Bar site) was covered by heavy fog with occasional light rain and drizzle.[33, 34, 35]

2.3-8 METEOROLOGY

WATTS BAR WBNP-101 Distributions of stability classes A-G are presented in Figures 2.3-6A and 2.3-6B. The average diurnal variations of stability class frequencies are quite evident, with the neutral (class D) and unstable (A, B, and C) lapse conditions predominant in the daytime and the stable classes (E, F, and G) predominant through the nighttime.

2.3.2.3 Potential Influence of the Plant and Its Facilities on Local Meteorology The Watts Bar site is about 45 miles north-northeast of Chattanooga. It is located on the west shore of Chickamauga Lake on the Tennessee River, which flows generally southwesterly through eastern Tennessee. The site (about 700 feet MSL) is near the center of a northeast-southwest aligned valley, 10 to 15 miles wide, flanked to the west by Walden Ridge (900 to 1,800 feet MSL,) and to the east by a series of ridges reaching elevations of 800 to 1,000 feet MSL. Figure 2.1-3 consists of a map of the topographic features (as modified by the plant) of the site area for 10 miles in all directions from the plant. Profiles of maximum elevation versus distance from the center of the plant are shown in Figures 2.3-14 through 2.3-29 for the sixteen compass point sectors (keyed to true north) to a radial distance of 10 miles.

The only plant systems which may have any pragmatic effects on the local climatic patterns of meteorological parameters discussed in the preceding section are the two natural draft cooling towers and their blowdown discharge system. During their operation, some small increase in ambient atmospheric moisture and temperature can be expected from the vapor plumes discharged from the tower tops. Also, some increase in the surface water temperature of Chickamauga Lake will be associated with the discharge of heated water from the plant (primarily the cooling tower blowdown). The vapor plumes may produce some additional localized fog on rare occasions on top of Walden Ridge (about eight miles, at its closest point, to the west-northwest). The increased lake surface temperature will likely increase the frequency of river steam fog slightly over a relatively small area of the reservoir downstream from the plant. No significant environmental impacts are expected from these effects. Discontinuities in ambient thermal structure of the atmosphere related to differential surface temperatures between land and water should produce no detectable effect on the local wind patterns or stability conditions. The physical plant structures will alter wind and stability somewhat in the immediate lee of the structures by mechanical turbulence factors produced in the building wake(s). However, these effects are expected to be generally insignificant beyond the first one or two thousand feet downwind.

2.3.2.4 Local Meteorological Conditions for Design and Operating Bases All design basis meteorological parameters are discussed or referenced in Section 2.3.1.3.

2.3.3 Onsite Meteorological Measurements Program 2.3.3.1 Preoperational Program Onsite meteorological facilities have been in operation since 1971 when a temporary 40-meter (130-foot) instrumented tower was installed. It was located about 760 meters (0.5 mile) west-southwest of the unit 1 Reactor Building and had a base elevation of METEOROLOGY 2.3-9

WATTS BAR WBNP-101 2 meters (8 feet) below plant grade. The temporary facility collected wind speed, wind direction, and temperature data at the 10-meter (33-foot) and 40-meter levels until it was decommissioned in September 1973. Since the FSAR dispersion meteorology data base was collected exclusively by the permanent facility, only that facility is described in detail in this section.

Permanent Meteorological Facility The permanent meteorological facility consists of a 91-meter (300-foot) instrumented tower for wind and temperature measurements, a separate 10-meter (33-foot) tower for dewpoint measurements, a ground-based instrument for rainfall measurements, and an environmental data station (EDS), which houses the data processing and recording equipment. A system of lightning and surge protection circuitry and proper grounding is included in the facility design. This facility is located approximately 760 meters south-southwest of the Unit 1 Reactor Building and has a base elevation of 4 meters (11 feet) below plant grade.

Data collected included: (1) wind direction and wind speed at 10, 46, and 91 meters; (2) temperature at 10, 46, and 91 meters; (3) dewpoint at 10 meters and (4) rainfall at 1 meter (3 feet). More exact measurement heights for the wind and temperature parameters are given in the EDS manual.[37] Elsewhere in the text of this document, temperature and wind sensor heights are given as 10, 46, and 91 meters.

Data collection at the permanent facility began May 23, 1973, with measurements of wind speed and wind direction at 10 and 93 meters (305 feet), temperature at 1, 10, 46, and 91 meters and dewpoint, and rainfall at 1 meter. Measurements of 46-meter wind speed and wind direction and 10-meter dewpoint began September 16, 1976.

Measurements of 1-meter dew point were discontinued September 30, 1977. Wind Sensors at 93-meter (actual height was 93.3 meters) were moved to their present height on May 18, 1978. Measurements of 1-meter temperature were discontinued on April 2, 1981. The 10-meter dewpoint sensor was removed from the meteorological tower and a new dewpoint sensor was installed on a separate tower 24 meters to the northwest on April 11, 1994.

Instrument Description A description of the meteorological sensors follows. More detailed sensor specifications are included in the EDS Manual. Replacement sensors, which may be of a different manufacturer or model, will satisfy the Regulatory Guide (RG)1.23 (Revision 1) specifications.[36]

2.3-10 METEOROLOGY

WATTS BAR WBNP-101 Height Sensor (Meters) Description Wind Direction 10, 46, and 91 Ultrasonic wind sensor.

and Wind Speed Temperature 10, 46, and 91 Platinum wire resistance temperature detector (RTD) with aspirated radiation shield.

Dewpoint 10 Capacitive humidity sensor.

Rainfall 1 Tipping bucket rain gauge.

Data Acquisition System The previous data collection system, which included a NOVA minicomputer, was replaced by a new system on March 2, 1989. This data acquisition system is located at the EDS and consists of meteorological sensors and a computer. These devices send meteorological data to the plant, to the Central Emergency Control Center (CECC) and to an offsite computer that enables callup for data validation and archiving.

System Accuracies The meteorological data collection system is designed and replacement components are chosen to meet or exceed specifications for accuracy identified in RG 1.23.

The meteorological data collection system satisfies the RG 1.23 accuracy requirements. A detailed listing of error sources for each parameter is included in the EDS manual.

Data Recording and Display The data acquisition is under control of the computer program. The output of each meteorological sensor is scanned periodically, scaled, and the data values are stored.

Meteorological sensor outputs are measured at the following rates: horizontal wind direction and wind speed, every five seconds (720 per hour); temperature and dewpoint, every minute (60 per hour); and rainfall, every hour (one per hour). Prior to February 1, 1975, only one reading of temperature and dewpoint was made each hour.

Software data processing routines within the computer accumulate output and perform data calculations to generate 15-minute and hourly average of wind speed and temperature, 15-minute and hourly vector wind speed and direction, hourly average of dewpoint, hourly horizontal wind direction sigmas, and hourly total precipitation. Prior to February 11, 1987, a prevailing wind direction calculation method was used.

Subsequently, vector wind speed and direction have been calculated along with arithmetic average wind speed.

METEOROLOGY 2.3-11

WATTS BAR WBNP-101 Selected data each 15 minutes and all data each hour are stored for remote data access.

Data sent to the plant control room every minute includes 10-, 46-, and 91-meter values for wind direction, wind speed, and temperature.

Data sent to the CECC computer every 15 minutes includes 10-, 46-, and 91-meter wind direction, wind speed, and temperature values. These data are available from the CECC computer to other TVA and the State emergency centers in support of the Radiological Emergency Plan, including the Technical Support Center at Watts Bar.

Remote access of meteorological data by the NRC is available through the CECC computer.

Data are sent from the EDS to an offsite computer for validation, reporting, and archiving.

Equipment Servicing, Maintenance, and Calibration The meteorological equipment at the EDS is kept in proper operating condition by staff that are trained and qualified for the necessary tasks.

Most equipment is calibrated or replaced at least every six months of service. The methods for maintaining a calibrated status for the components of the meteorological data collection system (sensors, electronics, data logger, etc.) include field checks, field calibration, and/or replacement by a laboratory calibrated component. More frequent calibration and/or replacement intervals for individual components may be conducted, on the basis of the operational history of the component type. Procedures and processes such as appropriate maintenance processes (procedures, work order/work request documents, etc.) are used to calibrate and maintain meteorological and station equipment.

2.3.3.2 Operational Meteorological Program The operational phase of the meteorological program includes those procedures and responsibilities related to activities beginning with the initial fuel loading and continuing through the life of the plant. This phase of the meteorological data collection program will be continuous without major interruptions. The meteorological program has been developed to be consistent with the guidance given in RG 1.23 (Revision 1) and the reporting procedure in RG 1.21 (Revision 1).[40] The basic objective is to maintain data collection performance to assure at least 90% joint recoverability and availability of data needed for assessing the relative concentrations and doses resulting from accidental or routine releases.

The restoration of the data collection capability of the meteorological facility in the event of equipment failure or malfunction will be accomplished by replacement or repair of affected equipment. A stock of spare parts and equipment is maintained to minimize and shorten the periods of outages. Equipment malfunctions or outages are detected by maintenance personnel during routine or special checks. Equipment outages that affect the data transmitted to the plant can be detected by review of data displays in the reactor control room. Also, checks of data availability to the emergency 2.3-12 METEOROLOGY

WATTS BAR WBNP-101 centers are performed each work day. When an outage of one or more of the critical data items occurs, the appropriate maintenance personnel will be notified.

In the event that the onsite meteorological facility is rendered inoperable, or there is an outage of the communication or data access systems; there is no fully representative offsite source of meteorological data for identification of atmospheric dispersion conditions. Therefore, TVA has prepared objective backup procedures to provide estimates for missing or garbled data. These procedures incorporate available onsite data (for a partial loss of data), offsite data, and conditional climatology. The CECC meteorologist will apply the appropriate backup procedures.

2.3.3.3 Onsite Data Summaries of Parameters for Dispersion Meteorology Annual joint frequency distributions of wind speed by wind direction for Pasquill atmospheric stability classes A-G, based on the onsite data for January 1974 through December 1993 are presented in Tables 2.3-45 through 2.3-52. These tables are summaries of hourly data for the wind at 10 meters and vertical temperature difference (T) between 10 and 46 meters (in the form of stability classes A-G). Tables 2.3-53 through 2.3-60 were prepared from the hourly data for the wind at 46 meters and T between 10 and 46 meters (as stability classes A-G) for January 1977 through December 1993. The frequency distributions in Tables 2.3-45 through 2.3-51 are also displayed in Figures 2.3-7 through 2.3-13.

The upvalley-downvalley primary wind pattern at 46 meters exists for all seven stability classes. The 10-meter wind level also shows upvalley-downvalley wind direction patterns. However, for classes E-G, the flow patterns become progressively more diffuse, with peaks from the northwest which become primary maxima in classes F and G (Tables 2.3-50 and 2.3-51). These directional peaks for the stable classes are most pronounced in the lighter wind speed ranges. The combination of these very light winds with the more stable conditions near the earth's surface indicate that very poor atmospheric dispersion conditions for ground-level plant releases of air-borne effluent occur most frequently at night and with the northwest wind direction.

The period of record for the joint frequency tables for the 46-meter wind measurement level is three years shorter than the record used for the 10-meter wind level. Collection of wind data at the 46-meter level began in September 1976. Tables 2.3-53 through 2.3-60 were originally prepared with 93-meter wind data and 10- to 91-meter T data for the July 1973-June 1975 period. The 46-meter wind level is near the height of the reactor building; and the 10- to 46-meter T interval is more representative than the 10- to 91-meter interval for stability classification, particularly for poorer dispersion conditions. The 10-meter wind level is applicable to design accident analysis and to semiannual reports on routine plant operations. The 46-meter wind level is used in radiological emergency dispersion and transport calculations.

The 20-year period for the tables with 10-meter wind data and the 17-year period for the tables with 46-meter wind data reasonably represent long-term dispersion conditions at the site. The length of the record is an important factor, and patterns of unusually wet weather in the 1970s and unusually dry weather in the 1980s are included in this data base. The dispersion meteorology varied during the 20-year METEOROLOGY 2.3-13

WATTS BAR WBNP-101 period, but the period is climatologically representative of long-term conditions. An increase in the frequency of 10-meter level calm winds (values less than 0.6 mi/hr) occurred in the early 1990s. The calm wind frequency increased from 1.6% for 1974-1988 to about 3.0% for 1974-1993. Consistent with the increase in calms, average wind speed decreased from 4.2 mi/hr for 1974-1988 to 4.1 mi/hr for 1974-1993.

Potential climate change associated with a global warming of the earth's lower atmosphere may occur in the Watts Bar site area. Should that occur during the life of this nuclear plant, the dispersion meteorology will be evaluated for any significant changes and consequent impacts on plant design and operation.

2.3.4 Short-Term (Accident) Diffusion Estimates 2.3.4.1 Objective Revised estimates of atmospheric diffusion expressed as dispersion factors (X/Q) have been calculated for accident releases considered as ground-level releases from the Watts Bar Nuclear Plant for specified time intervals and distances. The revised X/Q values are based on an updated onsite meteorological data base for 1974 through 1993 and RG 1.145 calculation methodology.[41] The original FSAR calculations were based on data collected at the Watts Bar onsite meteorological facility for the period July 1, 1973 through June 30, 1975 and R.G. 1.4 methodology.[42] All data used include wind direction and wind speed at 10 meters above ground and vertical temperature difference (T) between 10 and 46 meters above ground. The revised X/Q values at the exclusion area boundary and at the outer boundary of the low population zone (LPZ) were calculated as stated below.

Nomenclature for RG 1.145 Method X/Q = centerline ground-level relative concentration (sec/m3) y = lateral plume spread with meander and building wake effects (m), as a function of atmospheric stability, wind speed <<10, and distance (for distances greater than 800 meters, y = (M-1)y800m + y).

y = lateral plume spread as a function of atmospheric stability and distance (m).

z = vertical plume spread as a function of atmospheric stability and distance (m).

x = distance from effluent release point to point at which atmospheric dispersion factors (X/Q values) are computed (m).

U 10 = mean hourly horizontal wind speed at 10 meters (m/sec)

M = y correction factors for stability classes D, E, F, and G from Figure 3 in RG 1.145.

A = minimum containment and Auxiliary Building cross-sectional area (m2).

2.3-14 METEOROLOGY

WATTS BAR WBNP-101 Atmospheric dispersion factors (X/Q values) were calculated for a 1-hour averaging period and assumed to apply to the 2-hour period immediately following an accident.

The following equations were used to determine these values:

1 X e Q = -----------------------------------------------

- (1)

U 10 SV y V z + A e 2 1

X e Q = ---------------------------------- (2)

U 10 3SV y V z 1

X e Q = ------------------------- - (3)

U 10 S6 y V z For stability classes D, E, F, or G and windspeeds less than 6 meters per second (m/s),

the higher value from equations (1) and (2) was compared to the value from equation (3). The lower of these compared values was selected for the X/Q distributions. For wind speeds greater than 6 m/s in these classes and for all wind speeds in stability classes A, B, and C, the higher of the values from equations (1) and (2) was selected.

The minimum cross-sectional area, A, for Watts Bar Nuclear plant is 1630 m2. The exclusion boundary distance is 1200 m, as shown in Figure 2.1-4b. However, to avoid possible nonconservative accident X/Qs, the distance that was used to calculate the X/Qs is 1100 m, which is the minimum distance from the outer edge of the release zone to the exclusion area boundary. The assumed release zone is a 100-m radius circular envelope, which contains all of the structures that are potential sources of accidental releases of airborne radioactive materials. A distance of three miles (4828 m) was used as the low population zone (LPZ) outer boundary distance.

The 1-hour X/Q values for the exclusion boundary distance were distributed in the downwind 22.5-degree compass-point sectors (plume sectors) based on wind direction. Calm wind speeds (less than 0.6 mi/hr) were distributed based on the wind direction frequencies for non-calm wind speeds less than 3.5 mi/hr. The 0.5th and 5th percentile values for each sector and for all sectors combined were identified. For the LPZ distance, the 0.5th percentile and 5th percentile 1-hour values for each sector, the annual average values for each sector, and the 0.5th and 5th percentile 1-hour values for all sectors combined were determined. The annual average X/Qs were calculated from hourly average data according to guidance in Regulatory Guide 1.111 for constant mean wind direction models.[43] All calculations used an assumed wind speed of 0.6 mile per hour (0.268 m/s), which is the starting threshold of the anemometer, for hours with values less than that and thus defined as calms. Site-specific adjustment factors for terrain confinement and recirculation effects on concentrations at the LPZ distance were calculated and applied to the initial annual METEOROLOGY 2.3-15

WATTS BAR WBNP-101 average X/Qs. The method used to develop these adjustment factors is the same as that discussed in the offsite dose calculation manual for Watts Bar Nuclear Plant. The 16 sector adjustment factors are the following:

N NNE NE ENE E ESE SE SSE 1.36 1.65 2.01 1.61 1.58 1.81 1.28 1.49 S SSW SW WSW W WNW NW NNW 1.81 1.77 1.86 1.47 1.00 1.49 1.00 1.00 LPZ distance X/Qs for 8-hour, 16-hour, 3-day, and 26-day averaging periods were obtained by logarithmic interpolation between 1-hour values used for the 2-hour averaging period and annual average values. Sector values were interpolated between the 0.5th percentile 1-hour values assumed for the 2-hour time period and the annual average values for the respective sectors (e.g., between southeast sector 0.5th percentile 2-hour X/Q and southeast sector annual average X/Q). The 5th percentile overall site X/Q values were interpolated between the 5th percentile 1-hour value (assumed for the 2-hour time period) for all sectors combined and the maximum sector annual average value selected from the 16 sector annual average values.

2.3.4.2 Calculation Results The 1-hour sector-specific and overall (all directions combined) atmospheric dispersion factors (X/Q) for the exclusion boundary are presented in Table 2.3-61 based on the 15-year data set of 1974-1988 and Table 2.3.61a based on the 20-year data set of 1974-1993. The maximum 0.5th and 5th percentile X/Q values are from the 15-year data set and are 6.040 x 10-4 sec/m3 and 5.323 x 10-4 sec/m3, respectively.

The maximum 0.5th and 5th percentile X/Q values from the 20-year data sets (6.070 x 10-4 sec/m3 and 5.263 x 10-4 sec m3, respectively) are essentially unchanged from the 15-year values.

The 1-hour 0.5th percentile, 1-hour 5th percentile, and annual average X/Q values for each of the 16 plume sectors and the 1-hour overall 0.5th and 5th percentile X/Q values for the low population zone distance are presented in Table 2.3-62 based on the 15-year data set of 1974-1988 and Table 2.3-62a based on the 20-year set of 1974-1993. Only minor differences exist between the two sets of values.

For 8-hour, 16-hour, 3-day, and 26-day averaging periods, the X/Qs were obtained by logarithmic interpolation between the 1-hour and annual average X/Q values. The 5th percentile overall site 1-hour X/Q and the maximum sector annual average X/Q were used to produce the values given in Table 2.3-63 (1974-1988) and Table 2.3-63a (1974-1993).

The 0.5th percentile 1-hour X/Q and annual average X/Q for each sector were used to produce the values given in Table 2.3-64 (1974-1988) and Table 2.3-65 (1974-1993).

The maximum sector set corresponds to the southeast plume sector. The respective values are:

2.3-16 METEOROLOGY

WATTS BAR WBNP-101 Period 1974-1988 1974-1993

-5 8-hour 6.765 x 10 6.677 x 10-5 16-hour 4.629 x 10-5 4.592 x 10-5 3-day 2.032 x 10-5 2.039 x 10-5 26-day 6.230 x 10-6 6.353 x 10-6 In Section 2.3.3.3, the representativeness of the onsite data summarized in the joint frequency distributions of wind direction and wind speed by atmospheric stability class was discussed. Topographic effects have been mentioned previously, but some expansion relative to the 10-meter wind data is necessary. There is a predominance of northwest wind direction frequencies for a combination of very light wind speeds and quite stable atmospheric stability conditions. The terrain at the site has a general, gradual downward slope toward the south and southeast. Apparently, this is influencing the air flow over the site during periods with very light winds and stable conditions.

Dispersion meteorology used in accident analyses in Chapter 15 include X/Q values in Table 2.3-66 and 1/U values in Table 2.3-67. These values were based on the 15-year data set for 1974-1988. Table 2.3-66a and 2.3-67a present the same information based on the 20-year data set for 1974-1993. The original FSAR values are presented with the updated bases for comparison.

2.3.5 Long-Term (Routine) Diffusion Estimates The X/Qs and D/Qs and the respective calculation methodologies are presented in the Offsite Dose Calculation Manual for Watts Bar Nuclear Plant.

The joint frequency distributions of wind speed and wind direction by stability class in Tables 2.3-45 through 2.3-51 form the basis for Offsite Dose Calculation Manual estimation of long-term X/Qs. RG 1.111 methodology is used to calculate these X/Qs from the onsite meteorological data base. Additional information is provided in the Offsite Dose Calculation Manual.

The long-term representativeness of the 20-year onsite meteorological data base is discussed in Sections 2.3.3.3 and 2.3.4.2.

METEOROLOGY 2.3-17

WATTS BAR WBNP-101 REFERENCES (1) U. S. Atomic Energy Commission, A Meteorological Survey of the Oak Ridge Area, Weather Bureau, Publication ORO-99, Oak Ridge, Tennessee, November 1953, page 377.

(2) Ibid., page 192.

(3) Dickson, Robert R. Climates of the States - Tennessee, Climatography of the United States No. 60-40, U. S. Department of Commerce., Weather Bureau, February 1960, page 3.

(aa) Nashville NWS web site (http://www.srh.noaa.gov/ohx/?n=tornadodatabase) for Cumberland County [Accessed May 12, 2010].

(bb) Morristown NWS web site (http://www.srh.noaa.gov/mrx/?n=mrx_tornado_db) for Bledsoe, Hamilton, McMinn, Meigs, Rhea, and Roane Counties [Accessed May 12, 2010].

(cc) NUREG/CR-4461 (revision 2), Tornado Climatology of the Contiguous United States, February 2007.

(8) Thom, H.C.S. "Tornado Probabilities," Monthly Weather Review, October-December 1963, pages 730-736.

(dd) U.S. Department of Commerce. Local Climatological Data, Annual Summary with Comparative Data, 2009, Chattanooga, Tennessee, NOAA, National Climatic Data Center, Asheville, North Carolina.

(ee) U.S. Department of Commerce. Local Climatological Data, Annual Summary with Comparative Data, 2009, Knoxville, Tennessee, NOAA, National Climatic Data Center, Asheville, North Carolina.

(ff) National Climatic Data Center (NCDC) Storm Event database for 1950-2009 (http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~Storms).

(gg) U.S. Department of Commerce. "Climatic Summary of the United States -

Eastern Tennessee," Climatography of the United States No. 10-77, U.S.

Weather Bureau, Revised 1957.

(13) U.S. Department of Commerce. Climatography of the United States No. 20, 1971-2000, Tennessee.

(hh) NUREG/CR-3759, Lightning Strike Density fo Contiguous United States from Thunderstorm Duration Records, May 1984.

(15) Korshover, J. "Climatology of Stagnating Anticyclones East of the Rocky Mountains, 1936-1970," NOAA Technical Memorandum ERL ARL-34, U.S.

Department of Commerce, Air Resources Laboratories, Silver Spring, Maryland, October 1971.

2.3-18 METEOROLOGY

WATTS BAR WBNP-101 (16) Holzworth, G. C. Mixing Heights, Wind Speeds, and Potential for Urban Air Pollution Throughout the Contiguous United States, Environmental Protection Agency, Research Triangle Park, North Carolina, January 1972.

(17) U.S. Department of Commerce/U.S. Department of Agriculture. Weekly Weather and Crop Bulletin, NOAA/USDA Joint Agricultural Weather Facility, Washington, D.C., December 18, 1984, page 14.

(18) Tattelman, Paul, et al. "Estimated Glaze Ice and Wind Loads at the Earth's Surface for the Contiguous United States," Air Force Cambridge Research Laboratories, L. G. Hanscom Field, Massachusetts, October 16, 1973.

(19) American Meteorological Society. "Extremes of Snowfall: United States and Canada," Weatherwise, Vol. 23, December 1970, page 291.

(20) American National Standards Institute, Inc. "American National Standard Building Code Requirements for Minimum Design Loads in Buildings and Other Structures." A58.1-1972, New York, New York, Figure 4, page 27.

(21) Ludlum, David M. Weather Record Book, United States and Canada, Weatherwise, Inc., 1971, page 73.

(ii) NRC Regulatory Guide-1.76 (revision 1), "Design-Basis Tornado and Tornado Missiles for Nuclear Power Plants, March 2007.

(22) Thom, H. C. S. "New Distributions of Extreme Winds in the United States,"

"Journal of the Structural Division Proceedings of the American Society of Civil Engineers, Paper 6038, July 1968, pages 1787-1801.

(24) Deleted by Amendment 94.

(25) Magnetic tape of Chattanooga, Tennessee, National Weather Service Station data, obtained from the National Climatic Data Center, Asheville, North Carolina. Period of data analyzed, 1965-1971.

(26) U.S. Department of Commerce. Local Climatological Data, Annual Summary with Comparative Data, 2009, Oak Ridge, Tennessee, NOAA, National Climatic Data Center, Asheville, North Carolina.

(27) Hardwick, W. C. "Monthly Fog Frequency in the Continental United States,"

Monthly Weather Review, Volume 101, October 1973, pages 763-766.

(28) Tennessee Valley Authority. Final Safety Analysis Report for Sequoyah Nuclear Plant, Section 2.3, Figure 2.3-5.

(29) Hosler, C. R. "Low-Level Inversion Frequency in the Contiguous United States," Monthly Weather Review, Vol. 89, September 1961, pages 319-339.

METEOROLOGY 2.3-19

WATTS BAR WBNP-101 (30) U.S. Department of Commerce. Local Climatological Data, January 1982, Knoxville, Tennessee, NOAA, National Climatic Data Center, Asheville, North Carolina.

(31) U.S. Department of Commerce. Local Climatological Data, January 1982, Chattanooga, Tennessee, NOAA, National Climatic Data Center, Asheville, North Carolina.

(32) U.S. Department of Commerce. Daily Weather Maps, January 18-24, 1982, NOAA, Washington, D.C.

(33) U.S. Department of Commerce. Local Climatological Data, December 1989, Chattanooga, Tennessee, NOAA, National Climatic Data Center, Asheville, North Carolina.

(34) U.S. Department of Commerce. Local Climatological Data, December 1989, Knoxville, Tennessee, NOAA, National Climatic Data Center, Asheville, North Carolina.

(35) U.S. Department of Commerce. Daily Weather Maps, December 25-31, 1989, NOAA, Washington, D.C.

(36) U.S. NuclearRegulatory Commission. Regulatory Guide 1.23, Revision 1, "

Meteorological Monitoring Programs for Nuclear Power Plants," Washington, D.C., March 2007.

(37) Tennessee Valley Authority. "Watts Bar Nuclear Plant Environmental Data Station Manual."

(38) Deleted by Amendment 94.

(39) Deleted by Amendment 94.

(40) U.S. Atomic Energy Commission. Regulatory Guide 1.21, Revision 1, "Measuring, Evaluating, and Reporting Radioactivity in Solid Wastes and Releases of Radioactive Materials in Liquid and Gaseous Effluents from Light-Water-Cooled Nuclear Power Plants," Washington, D.C., June 1974.

(41) U.S. Nuclear Regulatory Commission. Regulatory Guide 1.145, Revision 1, "Atmospheric Dispersion Models for Potential Accident Consequence Assessment at Nuclear Power Plants," Washington, D.C., November 1982.

(42) U.S. Atomic Energy Commission. Regulatory Guide 1.4, Revision 2, "Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss of Coolant Accident for Pressurized Water Reactors," Washington, D.C., June 1974.

2.3-20 METEOROLOGY

WATTS BAR WBNP-101 (43) U.S. Nuclear Regulatory Commission. Regulatory Guide 1.111, Revision 1, "Methods for Estimating Atmospheric Transport and Dispersion of Gaseous Effluents in Routine Releases from Light-Water-Cooled Reactors,"

Washington, D.C., July 1977.

METEOROLOGY 2.3-21

WATTS BAR WBNP-101 Table 2.3-1 Thunderstorm Day Frequencies Chattanooga1 Knoxville2 December 0.6 0.7 January 1.3 0.8 February 2.0 1.4 Winter 3.9 2.9 March 3.6 3.2 April 4.8 4.5 May 7.1 6.9 Spring 15.5 14.6 June 9.0 8.5 July 11.1 9.9 August 8.8 6.9 Summer 28.8 25.3 September 4.0 3.0 October 1.4 1.3 November 1.5 1.1 Autumn 6.9 5.4 Annual 55.1 48.2 1 National Oceanic and Atmospheric Administration, 2009 Local Climatological Data Annual Summary with Comparative Data; Chattanooga, TN (KCHA) -- period of record 62 years.

2 National Oceanic and Atmospheric Administration, 2009 Local Climatological Data Annual Summary with Comparative Data; Knoxville, TN (KTYS) -- period of record 62 years.

2.3-22 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-1A Extreme Wind Speeds (Page 1 of 2)

This table lists the highest wind speeds observed at Chattanooga NWS, Knoxville NWS, and Watts Bar Nuclear Plant site for different time periods. Because the wind averaging periods varied, all observations were converted to 3-second gusts for comparison (based on ANSI/TIA-222-G, Annex L.a)

Chattanooga, Tennessee (National Weather Service Airport Station)

Period of Record = 1945-2009 (65 years).

Period Data Source (s) Date of Observed value Max 3-sec gust Occurence (averaging period) equivalent 1945-1975 Chattanooga (CHA) Local March 24, 82 mph 102 mph Climatological Data (LCD), 1947 (fastest mile) 1975 Annual and CHA LCD, March 1947.b 1976-1995 CHA LCD, 1995 Annual and November 11, 38 mph 48 mph CHA LCD, November 1995.b 1995. (2-min average) 47 mph (5-sec average) 1996-2009 CHA LCD, 2009 Annual and June 11, 63 mph 63 mph CHA LCD, June 2009.b 2009 (3 second gust)

Maximum wind speed (3-second gust equivalent) = 102 mph on March 24, 1947.

Knoxville, Tennessee (National Weather Service Airport Stations)

Period of Record = 1943-2009 (67 years).

Period Data Source (s) Date of Observed value Max 3-sec gust Occurence (averaging period) equivalent 1943-1974 Knoxville (TYS) LCD, 1974 July 15, 73 mph 88 mph Annual and TYS LCD, July 1961 (fastest mile) 1961.b 1975-1995 TYS LCD, 1995 Annual and November 11, 45 mph 56 mph TYS LCD, November 1995.b 1995. (2-min average) 54 mph (5-sec average) 1996-2009 TYS LCD, 2009 Annual and April 20, 76 mph 76 mph TYS LCD, June 2009.b 1996 (3 second gust)

Maximum wind speed (3-second gust equivalent) = 88 mph on July 15, 1961.

METEOROLOGY 2.3-23

WATTS BAR WBNP-101 Table 2.3-1A Extreme Wind Speeds (Page 2 of 2)

Watts Bar Meteorological Tower Period of Record = 1973-2009 (37 years).

Period Data Source (s) Date of Observed value Max 3-sec gust Occurence (averaging period) equivalent 1973-2009 TVA wind observations for Mar 25, 39 mph 5 mph 10- and 91-meter wind 1975 (hourly average) sensors Maximum wind speed (3-second gust equivalent) = 59 mph on March 25, 1975.

a. ANSI/TIA-222-G, Structural Standard for Antenna Supporting Structures and Antennas", effective January 1, 2006.

The relevant portion of Annex L, "Wind Speed Conversions" is provided below:

Fastest Mile 10-min average 3-sec gust (mph) Wind Speed Averaging Period Hourly mean (mph)

(mph) (sec) (mph) 60 50 72 42 40 70 58 62 49 46 80 66 55 56 53 85 70 51 59 56 90 75 48 62 60 95 78 46 66 63 100 80 45 69 66 105 85 42 73 70 Intermediate values are determined by interpolation.

b. Annual and Monthly Local Climatological Data reports (for applicable cities and time periods) from the NOAA National Climatic Data Center, Asheville, North Carolina.

2.3-24 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-1B Storm Events for Rhea and Surronding Counties (Page 1 of 2)

These tables list the storm events for Rhea and surrounding counties from the National Climatic Data Center (NCDC) Storm Event database for 1950-2009 (http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwEvent~Storms). Accessed August 20, 2010.

Listed counties are adjacent to Rhea county and/or have potions of the county within 10 miles of Watts Bar Nuclear Plant. Number of occurrences is for the entire county.

High winds:

Search Settings (except county): Begin Date = 01/01/1950 End Date = 12/31/2009 Event type = All High Wind Speed of at Least 50 Knots All other search settings default.

County Total Number of Occurrences Average Occurrences per Year

Rhea (including Watts Bar) 122 2.03 Bledsoe 103 1.72 Cumberland 91 1.52 Hamilton 275 4.58 McMinn 163 2.72 Meigs 82 1.36 Roane 144 2.40 TOTAL EVENTS 980 16.33 METEOROLOGY 2.3-25

WATTS BAR WBNP-101 Table 2.3-1B Storm Events for Rhea and Surronding Counties (Page 2 of 2)

Large Hail:

Search Settings (except county): Begin Date = 01/01/1950 End Date = 12/31/2009 Event type = Hail Hail, Size of at Least 0.75 Inches All other search settings default.

County Total Number of Occurrences Average Occurrences per Year

Rhea (including Watts Bar) 122 2.03 Bledsoe 103 1.72 Cumberland 91 1.52 Hamilton 275 4.58 McMinn 163 2.72 Meigs 82 1.36 Roane 144 2.40 TOTAL EVENTS 980 16.33

Total Number of Occurrences/60 years 2.3-26 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-2 Temperature Data Dayton and Decatur, Tennessee Coopertive Observer Data (Data in °F)

Average Average Extreme Extreme Daily Averageb Daily Maximumb Daily Minimumb Maximumc Minimumc Month Dayton Decatur Dayton Decatur Dayton Decatur Dayton Decatur Dayton Decatur Jan 36.2 40.0 45.9 50.6 26.5 29.4 75 76 -15f -9 Feb 40.5 41.6 51.6 53.0 29.3 30.3 79 78 -4 -20g Mar 48.8 50.5 60.8 63.0 36.7 38.1 85 91 3 2 Apr 57.4 58.5 70.3 72.0 44.4 45.0 92 94 22 20 May 65.4 67.1 77.3 80.8 53.5 53.5 94 99 30 30 Jun 73.3 74.6 84.7 87.2 61.8 62.0 100 103 40 40 e

Jul 76.9 77.6 87.7 89.8 66.1 65.3 107d 108 49 48 Aug 76.0 76.9 86.9 89.3 65.0 64.5 104 107 49 49 Sep 70.1 71.9 81.0 85.1 59.1 58.7 100 106 30 34 Oct 58.3 60.0 70.4 74.1 46.1 45.9 90 96 23 19 Nov 48.1 48.4 58.8 61.3 37.3 35.5 83 82 9 7 Dec 39.3 40.3 49.0 50.8 29.6 29.9 76 76 -5 -4 d e f Annual 57.5 59.0 68.7 71.4 46.3 46.5 107 108 -15 -20g

a. Cooperative Observer Stations

[Dayton, Tennessee] Climatography of the United States No. 20 1971-2000 (Station -

Dayton 2 SE, TN; COOP ID = 402360), National Climate Data Center, Ashville, NC.

[Decatur, Tennessee] Climatography of the United States No. 10-77, "Climatic Summary of the United States - Eastern Tennessee," U.S. Department of Commerce, Weather Bureau, revised 1957 and Annual NCDC Tennessee Climatological Data for individual years during 1896-1956.

b. Period of Record:

Dayton = 1971-2000 (30 years).

Decatur = 1896-1930 (35 years)

c. Period of Record:

Dayton = 1956-2001 (46 years).

Decatur = 1896-1945, 1952-1956 (60 years).

d. July 16, 1980.

e. July 28, 1930 and July 29, 1952.

f. January 21, 1985

g. Date unknown. According to Climatography of the United States No. 10-77, Decatur reported a low temperature of -20°F during 1896-1930. However, the specific date cannot be identified in the Annual NCDC Tennessee Climatological Data reports for the period. Coldest temperature for a known date was -19°F on January 26, 1940.

METEOROLOGY 2.3-27

WATTS BAR WBNP-101 Table 2.3-3 Temperature Data Chattanooga, Tennessee National Weather Servicea (Data in °F)

Normal Dry Mean Daily Mean Daily Extreme Extreme Month Bulba Maximumc Minimumc Maximumd Minimumd January 39.4 49.9 31.1 78 -10d February 43.4 52.8 32.5 79 1 March 51.4 62.3 40.0 89 8 April 59.6 71.7 47.8 93 25 May 67.7 80.0 56.7 99 34 June 75.4 86.3 64.4 104 41 July 79.6 89.6 69.0 106e 51 August 78.5 89.0 68.2 105 50 September 72.1 82.6 61.2 102 36 October 60.4 73 49.2 94 22 November 50.3 60.6 38.8 84 4 December 42.4 51.8 32.8 78 -2 Annual 60.0 70.8 49.3 106e -10d

a. National Oceanic and Atmospheric Administration, 2009 Local Climatological Data Annual Summary with Comparative Data; Chattanooga, TN (KCHA).

b. Period of Record = 1971-2000 (30 years).

c. Period of Record = 1928-2009 (82 Years).

d. Period of Record = 1940-2009 (70 Years).

e. January 1985.

f. July 1952.

2.3-28 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-4 Precipitation Data Watts Bar Nuclear Plant and Watts Bar Dam Precipitation Data (Inches)

(Data in Inches)

Average No.

of Days 0.01 Extreme Extreme 24-hour Inch or Morea Averageb Maximumc Minimumc Maximumc Month WBN* Dam* WBN Dam WBN Dam WBN Dam WBN Dam Jan 11 11 4.39 5.30 9.89 11.67 0.80 0.93 3.31 5.31d Feb 10 10 4.12 5.34 12.28 9.79 0.37 0.74 3.56 3.50 e

Mar 11 11 4.50 5.62 12.33 11.75 1.43 1.32 3.49 5.00 Apr 9 10 3.52 4.56 8.72 8.66 0.41 0.80 3.69 3.10 May 10 9 4.00 3.57 11.94 10.94 0.73 0.56 4.26 3.20 Jun 9 9 3.42 3.81 10.29 12.30 0.13 0.03 4.44 3.73 Jul 10 10 3.86 5.14 11.41 12.50 0.25 0.50 3.70 4.80 Aug 8 9 2.96 3.20 7.91 7.13 0.02 0.52 3.61 3.19 f g Sep 7 7 3.45 3.69 8.55 14.78 0.46 0.45 4.77 4.50 Oct 7 6 2.59 2.90 6.52 7.91 0.00 0.00 3.09 3.05 Nov 9 8 4.30 4.13 8.85 14.06 0.73 0.94 2.64 4.63 Dec 11 10 4.31 5.31 11.92 12.08 1.32 0.30 4.72 4.15 Annual 111 110 45.43 52.57

WBN = Watts Bar Nuclear Plant Meteorological tower. The meteorological facility is located 0.8 km south-southwest of Watts Bar Nuclear Plant. The rain gauge is 1 meter above ground.

Dam = TVA rain gauge station 421 at Watts Bar Dam. The Dam is located 1.9 km north of Watts Bar Nuclear Plant. The rain gauge is located on the roof of the Control Building at Watts Bar Dam.

- Annual totals do not equal the sum of monthly values due to rounding.

a. Period of record = 1974-2008 for Watts Bar Nuclear Plant and 1940-1975 for Watts Bar Dam.

b. Period of record = 1974-2008 for Watts Bar Nuclear Plant and 1941-1970 for Watts Bar Dam.

c. Period of record = 1974-2008 for Watts Bar Nuclear Plant and September 1939-September 1989 for Watts Bar Dam.

d. January 1946.

e. March 1975.

f. September 1957.

g. September 17, 1994.

METEOROLOGY 2.3-29

WATTS BAR WBNP-101 Table 2.3-5 Snowfall Data (Inches)

Dayton, Tennessee (Data in Inches)

Month Averagea,b Maximum Monthlya,c Highest Dailya,c January 1.8 9.7 7.2 February 1.6 13.3d 7.5 March 0.8 8.0 8.0e April 0.1 2.7 2.7 May 0 0 0 June 0 0 0 July 0 0 0 August 0 0 0 September 0 0 0 October 0 0 0 November Trace Trace Trace December 0.1 1.1 1.0 Annual 4.4

a. Climatography of the United States, No. 20, 1971-2000 (COOP ID = 402360).

b. Derived from Snow Climatology and 1971-2000 daily data.

c. Derived from 1971-2000 daily data.

d. February 1979

e. March 13, 1993.

2.3-30 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-6 Snowfall Data Chattanooga and Knoxville, Tennessee NWS (Data in Inches)

Normalc Maximum Monthlyd Maximum in 24 Hrs.d Month Chattanooga Knoxville Chattanooga Knoxville Chattanooga Knoxville January 2.0 3.7 10.2 15.1 10.2 12.0 February 1.3 3.0 10.4 23.3 8.7 17.5 March 1.2 1.6 20.0 20.2 20.0 14.1 April 0.2 0.8 2.8 10.7 2.8 10.7 May 0 0 trace trace trace trace June 0 0 trace trace trace trace July 0 0 0 0 0 0 August 0 0 0 trace 0 trace September 0 0 trace trace trace trace October *

trace trace trace trace November

0.1 2.8 18.2 2.8 18.2 December 0.1 0.7 9.1 12.2 8.9 8.9 Annual 4.8 9.9 20.0 23.3e 20.0 18.2

Value is between 0.00 and 0.05.

a. Local Climatological Data, Annual Summary with Comparative Data, 1983 and 2009, Chattanooga, Tennessee, U.S. Department of Commerce, NOAA, NCDC, Asheville, N.C.

b. Local Climatological Data, Annual Summary with Comparative Data, 1983 and 2009, Knoxville, Tennessee, U.S. Department of Commerce, NOAA, NCDC, Asheville, N.C.

c. Period of record for monthly normal is 30 years (1971-2000).

d. Period of record for maximum monthly and maximum 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months events is 72 years for Chattanooga and 65 years for Knoxville.

For Chattanooga, the maximum monthly and maximum 24-hour event was 20.0 inches during March 1993.

For Knoxville, the maximum monthly event was 23.3 inches during February 1960 and the maximum 24-hour event was 18.2 inches during November 1952.

e. Another site had the highest maximum monthly event for the Knoxville locality -- 25.7 inches in February 1895.

METEOROLOGY 2.3-31

WATTS BAR WBNP-101 Table 2.3-7 Average Relative Humidity Data (Percent) - Selected Hours Chattanooga, Tennessee*

(Eastern Standard Time)

Updated Data (1971-2000)1 Original Date (1931/41-1974)2 Hour Hour Hour Hour Hour Hour Hour Hour Month 0100 0700 1300 1900 0100 0700 1300 1900 January 79 81 63 66 80 82 63 68 February 77 82 58 58 78 80 57 60 March 76 82 55 53 77 81 53 56 April 78 85 49 49 78 81 49 52 May 87 89 55 58 86 85 51 56 June 87 90 57 60 88 85 54 60 July 87 90 57 62 89 89 57 64 August 88 92 58 64 90 91 57 66 September 89 92 59 66 89 90 55 66 October 88 91 55 68 88 89 52 67 November 83 86 59 68 82 84 55 65 December 80 83 62 68 82 83 62 70 Annual 83 87 57 62 84 85 55 63

1. Local Climatological Data, Annual Summary with Comparative Data, 1983 and 2009, Chattanooga, Tennessee, U.S. Department of Commerce, NOAA, NCDC, Asheville, N.C.

(Period of Record = 1971-2000).

2. Local Climatological Data, Annual Summary with Comparative Data, 1974, Chattanooga, Tennessee, U.S. Department of Commerce, NOAA, NCDC, Asheville, N.C. (Period of Record =

1941-1974 for hour 0100 and 1931-1974 for hours 0700, 1300, and 1900).

2.3-32 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-8 Relative Humidity (Percent)

National Weather Service Station Chattanooga, Tennessee*

January 1965-December 1971 Month Average Avg. Max. Avg. Min. Extreme Max. Extreme Min.

December 75.3 83.6 67.7 100.0 10.7 January 72.3 74.6 69.5 100.0 18.6 February 67.0 76.8 58.0 100.0 12.1 Winter 71.5 78.3 65.1 100.0 10.7 March 64.1 71.4 55.0 100.0 13.8 April 64.6 72.3 56.9 100.0 12.8 May 71.1 77.1 65.0 100.0 19.0 Spring 66.6 73.6 58.9 100.0 12.8 June 72.3 77.4 68.3 100.0 23.1 July 75.5 80.1 71.2 100.0 26.9 August 78.4 82.9 75.3 100.0 32.5 Summer 75.4 80.1 71.6 100.0 23.1 September 79.7 84.0 75.2 100.0 26.0 October 76.6 83.0 71.1 100.0 18.2 November 72.6 79.7 66.2 100.0 16.1 Fall 76.3 82.2 70.8 100.0 16.1 Annual 72.5 78.6 66.6 100.0 10.7

Analysis based on data tapes obtained from National Climatic Data Center, Asheville, North Carolina. Observations recorded on tape are for 3-hourly synoptic times.

METEOROLOGY 2.3-33

WATTS BAR WBNP-101 Absolute Humidity Chattanooga, Tennessee NWS (Data in gm/m3)

January 1965-December 1971*

Month Average Avg. Max. Avg. Min. Extreme Max. Extreme Min.

December 5.8 7.2 4.5 16.1 0.9 January 4.8 5.3 4.5 14.0 0.4 February 4.5 5.8 3.4 14.1 0.8 Winter 5.0 6.1 4.1 16.1 0.4 March 5.9 7.2 4.6 16.6 1.1 April 8.6 10.3 7.0 20.1 2.4 May 11.4 12.8 9.9 19.6 3.4 Spring 8.6 10.1 7.1 20.1 1.1 June 14.7 15.9 13.5 22.7 4.9 July 16.7 17.7 15.6 24.2 8.6 August 17.0 18.2 16.0 25.8 9.6 Summer 16.1 17.3 15.0 25.8 4.9 September 14.8 16.2 13.6 23.6 4.2 October 10.0 11.6 8.5 20.8 3.0 November 6.5 7.9 5.1 17.8 1.2 Fall 10.4 11.9 9.1 23.6 1.2 Annual 10.0 11.4 8.8 25.8 0.4

Analysis based on data tapes obtained from National Climatic Data Center, Asheville, North Carolina. Observations recorded on tape are for 3-hourly synoptic times.

2.3-34 METEOROLOGY

WATTS BAR WBNP-101 Relative Humidity Watts Bar Nuclear Plant Meteorological Facility (Sheet 1 of 2)

(Data in Percent)

July 1, 1973 - June 30, 1975

Average Average Extreme Extreme Month Average Maximum Minimum Maximum Minimum December 71.2 85.1 53.8 100.0 30.2 January 73.6 87.5 54.5 100.0 10.4 February 70.3 87.5 50.9 100.0 21.4 Winter 71.7 86.7 53.1 100.0 10.4 March 69.9 88.4 49.8 100.0 22.6 April 64.5 87.8 38.6 100.0 11.2 May 78.3 94.1 56.9 100.0 28.3 Spring 70.9 90.1 48.5 100.0 11.2 June 75.2 91.6 55.0 100.0 34.6 July 76.2 93.4 48.4 100.0 10.1 August 78.7 93.6 55.1 100.0 36.7 Summer 76.7 92.9 52.9 100.0 10.1 September 77.9 91.8 56.8 100.0 29.3 October 71.5 89.9 43.2 100.0 19.7 November 69.0 87.0 47.4 96.5 26.9 Fall 72.8 89.6 49.1 100.0 19.7 Annual 73.0

Data were collected at the Watts Bar Meteorological tower located 0.8 km SSW of Watts Bar Nuclear Plant. Temperature and dewpoint instruments at 4 feet above ground.

METEOROLOGY 2.3-35

WATTS BAR WBNP-101 Table 2.3-10 Relative Humidity Watts Bar Nuclear Plant Meteorological Facility (Sheet 2 of 2)

(Data in Percent)

January 1, 1976 - December 31, 2008

Average Average Extreme Extreme Month Average Maximum Minimum Maximum Minimum December 71.2 89.7 52.7 100.0 18.1 January 68.7 87.6 51.1 100.0 14.3 February 66.0 87.8 46.5 100.0 11.6 Winter 68.6 88.4 50.1 100.0 11.6 March 64.0 88.3 43.0 100.0 10.4 April 64.5 91.2 42.1 100.0 11.2 May 72.5 95.5 50.5 100.0 18.3 Spring 67.0 91.7 45.2 100.0 10.4 June 75.0 95.9 53.1 100.0 20.0 July 76.8 95.9 55.1 100.0 19.6 August 76.4 95.6 54.0 100.0 25.6 Summer 76.1 95.8 54.1 100.0 19.6 September 75.9 94.7 53.2 100.0 18.8 October 73.5 94.4 49.9 100.0 15.5 November 71.3 91.7 50.3 100.0 12.0 Autumn 73.6 93.6 51.1 100.0 12.0 Annual 71.3

Data were collected at the Watts Bar Meteorological tower located 0.8 km SSW of Watts Bar Nuclear Plant. Temperature and dewpoint instruments are 10 meters (33 feet) above ground.

Relative Humidity (RH) is calculated from simultaneous 10-m temperature (T) and 10-m dewpoint (Td) using equations from El Paso NWS website (http://www.srh.noaa.gov/epz/?n=wxcalc).

7.5*T d *

§ -------------------------

e © 237.6 + T d¹ RH = § -----* *100 where: e = 6.11* 10

§ ----------------------

T, Td = degrees celsius (°C) e, es = millibars (mb) 2.3-36 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-11 Absolute Humidity Watts Bar Nuclear Plant Meteorological Facility (Sheet 1 of 2)

(Data in gm/m3)

July 1, 1973 - June 30, 1975

Average Average Extreme Extreme Month Average Maximum Minimum Maximum Minimum December 5.2 6.6 4.0 14.5 1.5 January 6.1 7.8 4.3 13.2 1.0 February 5.7 7.3 4.3 15.1 1.5 Winter 5.7 7.2 4.2 15.1 1.0 March 7.1 8.9 5.3 14.7 1.8 April 8.3 10.3 6.4 17.7 2.0 May 13.7 15.9 11.6 21.5 4.9 Spring 9.7 11.7 7.8 21.5 1.8 June 14.7 17.2 12.4 22.1 7.8 July 17.1 19.3 13.7 22.7 1.8 August 16.7 18.9 14.9 24.4 10.1 Summer 16.2 18.4 13.7 24.4 1.8 September 14.4 16.5 12.5 21.9 4.9 October 9.2 11.0 7.7 17.7 3.1 November 7.0 8.7 5.4 16.6 2.1 Fall 10.2 12.1 8.5 21.9 2.1 Annual 10.4

Data were collected at the Watts Bar Meteorological tower located 0.8 km SSW of Watts Bar Nuclear Plant. Temperature and dewpoint instruments at 4 feet above ground.

METEOROLOGY 2.3-37

WATTS BAR WBNP-101 Absolute Humidity Watts Bar Nuclear Plant Meteorological Facility (Sheet 2 of 2)

(Data in gm/m3)

January 1, 1976 - December 31, 2008

Average Average Extreme Extreme Month Average Maximum Minimum Maximum Minimum December 5.1 6.5 4.2 16.5 0.5 January 4.4 5.7 3.6 14.7 0.4 February 4.7 6.1 3.9 14.2 0.6 Winter 4.8 6.1 3.9 16.5 0.4 March 6.1 7.8 5.0 17.6 0.8 April 8.3 10.3 6.8 18.8 1.6 May 11.9 14.0 10.4 24.0 3.1 Spring 8.8 10.7 7.4 24.0 0.8 June 15.4 17.5 13.6 24.8 5.3 July 17.5 19.5 15.6 27.1 7.1 August 16.9 19.0 15.1 27.6 7.2 Summer 16.6 18.7 14.8 27.6 5.3 September 14.0 16.0 12.3 21.9 3.8 October 9.7 11.5 8.3 21.9 1.7 November 6.9 8.4 5.7 19.0 1.2 Autumn 10.2 11.9 8.7 21.2 1.2 Annual 10.1

Data were collected at the Watts Bar Meteorological tower located 0.8 km SSW of Watts Bar Nuclear Plant. Temperature and dewpoint instruments are 10 meters (33 feet) above ground.

Absolute Humidity (AH) is calculated from simultaneous 10-m temperature (T) and 10-m vapor pressure (Pw = e from Table 2.3-10) using equation from User's Guide - Vaisala HUMICAP Humidity and Temperature Transmitter Series HMT330.

Pw AH = 216.68 * §© --------*¹ T

units: AH = grams/cubic meter (g/m3)

T = degrees kelvin (°K)

Pw = millibars (mb) 2.3-38 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-12 Fog Data*

Est. from Month Chat.a Knox.b Oak R.c Hardwickd January 2.8 2.6 2.5 1 February 1.5 1.8 1.3 2 March 1.2 1.7 1.8 1 April 1.3 1.3 1.7 1 May 2.2 2.2 5.5 2 June 1.6 1.8 4.8 2 July 1.5 2.1 5.8 2 August 1.9 3.5 5.2 3 September 3.3 3.8 7.5 4 October 4.8 4.3 7.8 6 November 3.3 2.9 4.5 4 December 2.4 2.4 4.3 3 Annual 27.8 30.4 52.7 33

Mean number of days with heavy fog, which is defined by horizontal visibility 1/4 mile or less.

a. Local Climatological Data, Annual Summary with Comparative Data, 2009, Chattanooga, Tennessee, U.S. Department of Commerce, NOAA, NCDC, Asheville, North Carolina. Period of record = 46 years.

b. Local Climatological Data, Annual Summary with Comparative Data, 2009, Knoxville, Tennessee, U.S.

Department of Commerce, NOAA, NCDC, Asheville, North Carolina. Period of record = 46 years.

c. Local Climatological Data, Annual Summary with Comparative Data, 2009, Oak Ridge, Tennessee, U.S. Department of Commerce, NOAA, NCDC, Asheville, North Carolina. Period of record = 10 years.

d. Hardwick, W. C. "Monthly Fog Frequency in the Continental United States", Monthly Weather Review, Volume 101, October 1973, pages 763-766.

METEOROLOGY 2.3-39

2.3-40 WATTS BAR Table 2.3-13 Joint Percentage Frequencies of Wind Speed By Wind Direction Disregarding Stability Class Watts Bar Nuclear Plant Jan 1, 1974 - Dec 31, 1993 WIND WIND SPEED(MPH)

DIRECTION CALM 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 TOTAL N 0.125 0.707 1.399 1.677 1.445 1.578 0.074 0.000 0.000 7.004 NNE 0.124 0.615 1.407 2.043 1.956 2.127 0.112 0.000 0.000 8.446 NE 0.160 0.728 1.957 1.783 1.051 0.695 0.011 0.001 0.000 6.386 ENE 0.242 1.112 2.944 1.296 0.425 0.150 0.002 0.000 0.000 6.170 E 0.151 0.992 1.540 0.583 0.138 0.045 0.002 0.000 0.000 3.451 ESE 0.059 0.438 0.546 0.192 0.028 0.013 0.001 0.000 0.000 1.277 SE 0.086 0.609 0.834 0.319 0.076 0.048 0.014 0.000 0.000 1.985 SSE 0.145 0.892 1.540 0.598 0.176 0.141 0.037 0.003 0.000 3.532 S 0.222 1.106 2.621 1.844 0.869 0.732 0.204 0.021 0.001 7.620 SSW 0.281 1.209 3.504 4.017 3.001 3.115 0.611 0.048 0.000 15.786 SW 0.237 1.479 2.506 1.516 0.756 0.470 0.072 0.004 0.001 7.040 WSW 0.239 1.888 2.135 0.666 0.372 0.317 0.082 0.004 0.000 5.702 W 0.235 2.104 1.843 0.646 0.546 0.653 0.090 0.008 0.002 6.127 WNW 0.212 2.052 1.505 0.637 0.597 0.821 0.086 0.005 0.000 5.915 NW 0.266 2.455 2.061 0.765 0.722 1.026 0.102 0.002 0.000 7.354 NNW 0.168 1.354 1.463 0.975 0.921 1.242 0.082 0.001 0.000 6.205 SUBTOTAL 2.951 19.738 29.823 19.554 13.081 13.172 1.583 0.095 0.003 100.00 TOTAL HOURS OF VALID W IND OBSERVATIONS169102 TOTAL HOURS OF OBSERVATIONS175320 RECOVERABILITY PERCENTAGE96.5 TOTAL HOURS CALM4990 METEOROLOGY METEOROLOGICAL FACILITY: W ATTS BAR NUCLEAR PLANT WBNP-101 W IND SPEED AND DIRECTION M EASURED AT 9.72 M ETER LEVEL M EAN W IND SPEED = 4.07Date Printed: 29-NOV-94 NOTE: TOTALS AND SUBTOTALS ARE OBTAINED FROM UNROUNDED NUM BERS

METEOROLOGY WATTS BAR Table 2.3-14 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 Wind ( Wind Speed(Mph)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.109 0.561 1.284 1.176 1.327 2.822 0.419 0.019 0.000 7.788 NNE 0.189 0.809 2.381 2.260 2.104 2.940 0.437 0.008 0.000 11.128 NE 0.272 1.144 3.460 2.490 1.633 1.555 0.126 0.002 0.000 10.682 ENE 0.215 1.013 2.622 1.257 0.579 0.393 0.024 0.000 0.000 6.203 E 0.109 0.774 1.061 0.488 0.195 0.087 0.008 0.000 0.000 2.722 ESE 0.056 0.418 0.526 0.279 0.059 0.026 0.002 0.001 0.000 1.367 SE 0.061 0.387 0.642 0.334 0.103 0.093 0.024 0.008 0.000 1.652 SSE 0.112 0.574 1.313 0.671 0.217 0.240 0.097 0.018 0.000 3.242 S 0.191 0.765 2.456 1.791 0.887 0.875 0.314 0.093 0.013 7.386 SSW 0.237 0.745 3.261 4.368 3.484 4.555 1.901 0.355 0.032 18.939 SW 0.140 0.584 1.787 2.080 1.732 2.366 0.714 0.103 0.015 9.521 WSW 0.085 0.448 0.981 0.747 0.514 0.764 0.294 0.073 0.017 3.922 W 0.068 0.428 0.721 0.428 0.396 0.859 0.327 0.049 0.007 3.282 WNW 0.056 0.390 0.549 0.416 0.450 1.243 0.438 0.031 0.001 3.573 NW 0.062 0.388 0.661 0.486 0.650 1.398 0.391 0.027 0.001 4.065 NNW 0.065 0.387 0.710 0.622 0.714 1.554 0.457 0.021 0.001 4.530 Subtotal 2.026 9.813 24.413 19.894 15.143 21.770 6.045 0.808 0.087 100.000 Total Hours Of Valid Wind Observations 142902 Total Hours Of Observations 149016 Recoverability Percentage 95.9 Total Hours Calm 2895 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Mean Wind Speed = 5.6981 Date Printed: 29-NOV-94 Note: Totals And Subtotals Are Obtained From Unrounded Numbers 2.3-41 WBNP-101

METEOROLOGY WATTS BAR Table 2.3-15 Wind Direction Persistence Data Disregarding Stability, Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 (Sheet 1 of 2)

Wind Direction ACC. ACC.

N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW CALM TOTAL TOTAL FREQUENCY 2 860 887 906 938 487 134 208 462 1085 1242 1030 782 879 783 988 802 344 12817 28445 100.00 3 360 465 388 428 201 44 77 196 496 697 392 328 353 328 481 373 186 5793 15628 54.94 4 241 298 253 220 71 9 27 77 275 531 219 132 182 179 255 212 113 3294 9835 34.58 5 159 169 146 122 30 1 11 30 174 417 130 67 114 127 162 114 72 2045 6541 23.00 6 112 160 89 64 18 0 5 21 102 289 46 42 61 68 99 81 61 1318 4496 15.81 7 74 93 70 37 7 0 3 4 50 269 38 20 20 34 63 52 45 879 3178 11.17 8 75 78 39 20 2 0 0 5 29 187 26 20 34 18 56 25 29 643 2299 8.08 9 36 42 20 11 0 0 0 2 18 139 17 5 9 17 22 30 23 391 1656 5.82 10 29 54 14 12 0 0 0 2 14 123 8 6 9 8 12 13 20 324 1265 4.45 11 25 30 9 4 0 0 0 0 13 99 5 4 6 12 11 11 9 238 941 3.31 12 15 19 3 1 0 0 3 1 11 79 1 0 3 2 2 7 4 151 703 2.47 13 14 16 4 2 0 0 0 0 3 62 2 2 2 2 4 6 5 124 552 1.94 14 5 13 4 0 0 0 0 0 2 49 3 0 1 2 0 3 6 88 428 1.50 15 5 14 0 1 0 0 0 0 2 42 3 1 1 0 1 6 2 78 340 1.20 16 4 8 3 1 1 0 0 0 0 21 0 1 1 1 2 2 0 45 262 0.92 17 4 9 1 0 0 0 0 0 1 20 1 0 0 0 1 2 0 39 217 0.76 18 3 6 2 0 0 0 0 1 0 22 1 1 0 0 1 0 0 37 178 0.63 19 3 8 0 0 0 0 0 0 0 19 0 0 1 1 2 1 0 35 141 0.50 20 4 6 0 0 0 0 0 0 0 10 0 0 0 0 0 0 0 20 106 0.37 21 1 5 0 0 0 0 0 0 0 2 1 0 0 0 1 3 0 13 86 0.30 22 1 7 0 0 0 0 0 0 0 6 0 0 0 0 0 0 0 14 73 0.26 23 1 0 0 0 0 0 0 0 1 6 0 0 0 0 1 1 0 10 59 0.21 24 0 5 0 0 0 0 0 0 0 3 0 0 0 0 0 1 0 9 49 0.17 25 1 0 0 0 0 0 0 0 1 3 0 0 0 0 0 1 0 6 40 0.14 26 0 1 1 0 0 0 0 0 0 6 0 0 0 0 2 0 0 10 34 0.12 27 0 0 0 0 0 0 0 0 0 3 0 0 0 0 1 0 0 4 24 0.08 28 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 1 0 4 20 0.07 29 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16 0.06 30 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 4 16 0.06 31 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 12 0.04 WBNP-101 32 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 2 12 0.04

>32 0 3 0 0 0 0 0 0 0 7 0 0 0 0 0 0 0 10 10 0.04 2.3-42 TOTAL 2032 2396 1952 1861 817 188 334 801 2277 4362 1923 1411 1676 1582 2167 1747 919 28445

Table 2.3-15 Wind Direction Persistence Data METEOROLOGY WATTS BAR Disregarding Stability, Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 (Sheet 2 of 2)

Wind Direction ACC. ACC.

N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW CALM TOTAL TOTAL FREQUENCY Maximum Persistence 25 40 26 16 16 5 12 18 25 44 21 18 19 19 27 28 15 (Hours) 50.0% 3 3 3 2 2 2 2 2 3 4 2 2 2 3 3 3 3 80.0% 6 6 5 4 3 3 3 3 4 8 4 4 4 4 5 5 6 90.0% 8 9 6 5 4 3 4 4 6 11 5 5 5 6 6 6 8 99.0% 16 20 11 10 7 4 7 8 11 21 10 10 10 11 11 15 13 99.9% 22 37 18 15 16 5 12 18 17 34 18 16 16 16 26 25 15 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At The 9.72 Meter Level 2.3-43 WBNP-101

METEOROLOGY WATTS BAR Table 2.3-16 Wind Direction Persistence Data Disregarding Stability, Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 (Sheet 1 of 2)

Persistence Wind Direction ACC. ACC.

(Hours) N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW CALM TOTAL TOTAL FREQUENCY 2 772 1014 1137 822 323 145 174 414 1015 1244 1088 489 370 367 412 491 245 10522 24808 100.00 3 348 503 539 353 102 32 60 134 438 735 503 148 123 171 205 247 128 4769 14286 57.59 4 227 360 403 200 45 16 19 65 212 577 344 87 82 124 106 120 73 3060 9517 38.36 5 168 182 275 98 12 4 11 28 124 391 191 45 47 64 77 79 38 1834 6457 26.03 6 122 165 169 59 4 0 7 10 79 285 130 26 33 55 50 49 40 1283 4623 18.64 7 77 128 122 31 3 0 0 6 34 249 77 13 13 31 37 31 18 870 3340 13.46 8 54 73 70 18 2 0 1 5 21 175 58 8 14 14 17 31 11 572 2470 9.96 9 47 59 57 7 0 0 2 1 9 148 43 8 10 14 21 17 8 451 1898 7.65 10 27 46 35 8 0 0 0 2 11 124 16 1 5 6 14 8 1 304 1447 5.83 11 20 36 18 4 0 0 0 1 8 99 13 3 1 7 6 11 5 232 1143 4.61 12 20 36 31 1 0 0 0 0 3 81 10 2 3 3 6 10 1 207 911 3.67 13 11 23 14 1 0 0 0 1 2 60 10 2 3 0 6 2 0 135 704 2.84 14 18 15 10 0 0 0 0 0 0 64 6 1 2 2 3 4 1 126 569 2.29 15 10 23 10 0 0 0 0 0 0 54 3 2 1 1 5 1 0 110 443 1.79 16 5 16 4 0 0 0 0 0 0 31 0 0 2 2 1 2 0 63 333 1.34 17 4 7 2 0 0 0 0 0 0 29 1 0 0 0 2 1 0 46 270 1.09 18 2 9 3 0 0 0 0 1 0 31 1 0 0 0 1 1 0 49 224 0.90 19 3 8 1 0 0 0 0 0 0 16 1 0 0 1 0 1 0 31 175 0.71 20 0 7 1 0 0 0 0 0 0 17 3 1 0 0 1 0 0 30 144 0.58 21 1 5 2 0 0 0 0 0 0 5 2 0 0 0 0 1 0 16 114 0.46 22 2 6 1 0 0 0 0 0 0 14 1 0 0 0 1 0 0 25 98 0.40 23 1 3 0 0 0 0 0 0 0 9 2 0 0 0 0 0 0 15 73 0.29 24 0 1 0 0 0 0 0 0 0 5 0 0 0 0 0 0 1 7 58 0.23 25 0 3 0 0 0 0 0 0 0 5 2 0 0 0 0 0 0 10 51 0.21 26 0 0 2 0 0 0 0 0 0 3 0 0 0 0 0 0 0 5 41 0.17 WBNP-101 27 1 2 2 0 0 0 0 0 0 2 1 0 0 0 0 0 0 8 36 0.15 28 1 0 0 0 0 0 0 0 0 5 0 0 0 0 1 0 0 7 28 0.11 2.3-44 29 0 1 0 0 0 0 0 0 0 7 0 0 0 0 0 0 0 8 21 0.08

Table 2.3-16 Wind Direction Persistence Data METEOROLOGY WATTS BAR Disregarding Stability, Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 (Sheet 2 of 2)

Persistence Wind Direction ACC. ACC.

(Hours) N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW CALM TOTAL TOTAL FREQUENCY 30 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 13 0.05 31 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 2 12 0.05 32 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 10 0.04

>32 0 1 0 0 0 0 0 0 0 8 0 0 0 0 0 0 0 9 9 0.04 TOTAL 1941 2733 2908 1602 491 197 274 668 1956 4475 2507 836 709 862 972 1107 570 24808 MAXIMUM PERSISTENCE (HOURS) 28 33 27 13 8 5 9 18 13 48 32 20 16 19 28 21 24 50.0% 3 3 3 2 2 2 2 2 2 4 3 2 2 3 3 3 3 80.0% 6 6 5 4 3 3 3 3 4 8 5 4 4 5 5 5 5 90.0% 8 9 7 5 4 4 4 4 5 12 7 5 6 6 7 7 6 99.0% 16 20 14 9 7 5 8 8 10 23 13 11 13 12 15 13 11 99.9% 27 29 26 12 8 5 9 18 13 34 25 20 16 19 28 19 24 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At The 46.36 Meter Level 2.3-45 WBNP-101

METEOROLOGY WATTS BAR Table 2.3-17 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant January (74-93)

Wind Speed(MPH)

Wind Direction CALM 0.6-1.4 1.5-3.4 3.5-5. 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.123 0.767 1.411 1.555 1.795 2.158 0.075 0.000 0.000 7.883 NNE 0.136 0.527 1.891 2.418 2.377 2.151 0.110 0.000 0.000 9.609 NE 0.181 0.870 2.343 1.884 1.069 0.548 0.000 0.000 0.000 6.894 ENE 0.238 1.117 3.110 1.110 0.356 0.110 0.000 0.000 0.000 6.040 E 0.130 0.829 1.486 0.370 0.151 0.096 0.000 0.000 0.000 3.062 ESE 0.043 0.329 0.432 0.123 0.034 0.021 0.000 0.000 0.000 0.981 SE 0.060 0.336 0.740 0.144 0.027 0.000 0.000 0.000 0.000 1.307 SSE 0.116 0.658 1.411 0.329 0.103 0.014 0.027 0.021 0.000 2.678 S 0.130 0.555 1.754 1.130 0.706 0.432 0.178 0.014 0.000 4.897 SSW 0.211 0.836 2.911 3.569 2.466 2.850 0.569 0.021 0.000 13.431 SW 0.150 0.849 1.822 1.514 0.870 0.555 0.151 0.000 0.000 5.911 WSW 0.179 1.144 2.041 1.240 0.877 0.733 0.315 0.007 0.000 6.536 W 0.188 1.445 1.904 0.980 1.185 1.329 0.288 0.014 0.000 7.333 WNW 0.168 1.459 1.521 0.959 1.089 1.623 0.158 0.000 0.000 6.976 NW 0.208 1.692 2.007 1.144 1.260 1.904 0.212 0.000 0.000 8.428 NNW 0.164 1.144 1.767 1.288 1.480 2.048 0.144 0.000 0.000 8.034 SUBTOTAL 2.425 14.556 28.550 19.755 15.844 16.570 2.226 0.075 0.000 100.000 Total Hours Of Valid Wind Observations 14599 Total Hours Of Observations 14880 Recoverability Percentage 98.1 Total Hours Calm 354 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 4.57 Note: Totals And Subtotals Are Obtained From Unrounded Numbers 2.3-46

METEOROLOGY WATTS BAR Table 2.3-18 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant January (77-93)

Wind Speed (MPH)

Wind Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.086 0.372 1.510 1.147 1.446 3.400 0.678 0.000 0.000 8.639 NNE 0.140 0.565 2.504 2.496 2.617 3.473 0.557 0.000 0.000 12.352 NE 0.170 0.687 3.045 2.722 1.971 1.745 0.057 0.000 0.000 10.395 ENE 0.136 0.678 2.310 1.018 0.533 0.226 0.000 0.000 0.000 4.901 E 0.085 0.598 1.260 0.218 0.057 0.024 0.000 0.000 0.000 2.241 ESE 0.030 0.315 0.339 0.089 0.016 0.000 0.000 0.000 0.000 0.789 SE 0.036 0.380 0.420 0.073 0.073 0.016 0.000 0.008 0.000 1.006 SSE 0.065 0.372 1.058 0.331 0.137 0.024 0.008 0.000 0.000 1.995 S 0.104 0.525 1.769 1.171 0.509 0.428 0.121 0.065 0.016 4.708 SSW 0.142 0.412 2.714 3.497 2.859 4.038 1.381 0.291 0.032 15.367 SW 0.090 0.485 1.486 1.688 1.672 2.811 0.743 0.105 0.032 9.112 WSW 0.066 0.428 1.018 0.767 0.670 1.373 0.517 0.178 0.065 5.082 W 0.050 0.291 0.808 0.420 0.775 1.615 0.759 0.218 0.032 4.969 WNW 0.041 0.363 0.541 0.614 0.905 2.367 0.880 0.057 0.000 5.768 NW 0.042 0.258 0.670 0.743 1.220 2.609 0.953 0.065 0.000 6.560 NNW 0.050 0.307 0.792 0.775 1.074 2.423 0.695 0.000 0.000 6.116 SUBTOTAL 1.333 7.035 22.244 17.769 16.533 26.573 7.350 0.985 0.178 100.000 Total Hours Of Valid Wind Observations 12381 Total Hours Of Observations 12648 Recoverability Percentage 97.9 Total Hours Calm 165 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed and Direction Measured at 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 6.34 2.3-47 Note: Totals and Subtotals are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-19 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant February (74-93)

Wind Speed (MPH)

Wind Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.120 0.693 1.701 1.807 1.634 2.319 0.083 0.000 0.000 8.357 NNE 0.128 0.745 1.807 2.492 2.499 2.868 0.151 0.000 0.000 10.691 NE 0.170 0.896 2.477 2.078 1.250 0.896 0.030 0.000 0.000 7.796 ENE 0.258 1.536 3.584 1.250 0.354 0.128 0.000 0.000 0.000 7.108 E 0.118 0.858 1.491 0.467 0.196 0.083 0.008 0.000 0.000 3.220 ESE 0.035 0.331 0.361 0.098 0.045 0.000 0.000 0.000 0.000 0.871 SE 0.049 0.474 0.497 0.196 0.038 0.060 0.000 0.000 0.000 1.314 SSE 0.069 0.519 0.851 0.339 0.136 0.128 0.038 0.008 0.000 2.087 S 0.116 0.625 1.679 0.994 0.474 0.550 0.294 0.023 0.000 4.753 SSW 0.166 0.806 2.492 2.989 2.612 3.433 1.242 0.053 0.000 13.792 SW 0.138 0.866 1.882 1.558 1.001 1.084 0.173 0.008 0.000 6.711 WSW 0.152 1.084 1.935 0.986 0.647 0.798 0.256 0.008 0.000 5.866 W 0.147 1.302 1.611 0.858 0.768 1.182 0.188 0.008 0.000 6.064 WNW 0.117 1.137 1.189 0.715 0.949 1.438 0.256 0.023 0.000 5.824 NW 0.180 1.724 1.844 1.024 1.287 1.777 0.196 0.000 0.000 8.032 NNW 0.123 1.031 1.415 1.340 1.235 2.198 0.173 0.000 0.000 7.516 SUBTOTAL 2.085 14.628 26.816 19.190 15.125 18.942 3.087 0.128 0.000 100.000 Total Hours Of Valid Wind Observations 13283 Total Hours Of Observations 13560 Recoverability Percentage 98.0 Total Hours Calm 277 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 4.84 2.3-48 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-20 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant February (77-93)

Wind Speed (MPH)

Wind Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.073 0.380 1.396 1.228 1.926 3.825 0.821 0.035 0.000 9.684 NNE 0.139 0.654 2.729 3.074 2.526 3.842 0.707 0.000 0.000 13.672 NE 0.203 0.760 4.160 3.118 2.261 1.926 0.274 0.000 0.000 12.702 ENE 0.137 0.830 2.491 1.316 0.742 0.389 0.035 0.000 0.000 5.940 E 0.056 0.503 0.848 0.397 0.132 0.053 0.035 0.000 0.000 2.025 ESE 0.026 0.256 0.371 0.159 0.018 0.000 0.000 0.000 0.000 0.830 SE 0.026 0.203 0.433 0.168 0.035 0.071 0.009 0.000 0.000 0.945 SSE 0.040 0.300 0.680 0.344 0.088 0.106 0.097 0.035 0.000 1.692 S 0.076 0.380 1.457 0.839 0.486 0.627 0.424 0.115 0.009 4.413 SSW 0.086 0.336 1.749 2.562 2.208 4.107 2.129 0.627 0.053 13.857 SW 0.067 0.336 1.281 1.952 1.625 2.835 1.086 0.194 0.026 9.403 WSW 0.044 0.274 0.804 0.768 0.530 1.157 0.530 0.159 0.035 4.302 W 0.040 0.318 0.662 0.495 0.477 1.334 0.592 0.150 0.009 4.077 WNW 0.031 0.318 0.424 0.459 0.601 2.005 0.804 0.088 0.000 4.730 NW 0.033 0.238 0.556 0.415 1.042 2.579 0.698 0.044 0.000 5.606 NNW 0.045 0.318 0.768 0.839 0.954 2.252 0.874 0.071 0.000 6.122 SUBTOTAL 1.122 6.404 20.811 18.134 15.652 27.109 9.116 1.519 0.132 100.000 Total Hours Of Valid Wind Observations 11321 Total Hours Of Observations 11520 Recoverability Percentage 98.3 Total Hours Calm 127 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed and Direction Measured at 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 6.68 Note: Totals and Subtotals are Obtained From Unrounded Numbers 2.3-49

METEOROLOGY WATTS BAR Table 2.3-21 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant March (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.097 0.546 1.596 1.659 1.484 2.331 0.189 0.000 0.000 7.903 NNE 0.103 0.770 1.498 1.806 1.729 2.576 0.112 0.000 0.000 8.595 NE 0.142 0.924 2.212 1.421 1.001 1.113 0.028 0.000 0.000 6.842 ENE 0.223 1.365 3.563 1.029 0.504 0.175 0.014 0.000 0.000 6.874 E 0.112 0.903 1.575 0.511 0.161 0.035 0.000 0.000 0.000 3.298 ESE 0.042 0.392 0.546 0.154 0.070 0.021 0.007 0.000 0.000 1.233 SE 0.059 0.581 0.714 0.280 0.119 0.168 0.105 0.000 0.000 2.026 SSE 0.075 0.609 1.043 0.553 0.217 0.406 0.133 0.000 0.000 3.036 S 0.101 0.658 1.568 1.316 0.658 1.344 0.588 0.091 0.007 6.332 SSW 0.137 0.721 2.303 3.402 3.171 5.419 1.911 0.063 0.000 17.128 SW 0.121 0.868 1.806 1.624 1.155 1.043 0.189 0.000 0.007 6.814 WSW 0.138 1.169 1.883 0.679 0.469 0.574 0.105 0.014 0.000 5.032 W 0.127 1.519 1.288 0.693 0.539 1.099 0.210 0.063 0.021 5.560 WNW 0.109 1.246 1.155 0.651 0.616 1.330 0.161 0.028 0.000 5.296 NW 0.142 1.533 1.603 1.036 0.882 1.890 0.266 0.021 0.000 7.374 NNW 0.092 0.847 1.190 1.008 1.253 2.051 0.210 0.007 0.000 6.659 SUBTOTAL 1.820 14.653 25.546 17.824 14.030 21.577 4.229 0.287 0.035 100.000 Total Hours of Valid Wind Observations 14284 Total Hours of Observations 14880 Recoverability Percentage 96.0 Total Hours Calm 260 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed and Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 5.17 2.3-50 Note: Totals and Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-22 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant March (77-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.106 0.449 1.379 1.246 1.346 3.879 0.797 0.066 0.000 9.269 NNE 0.172 0.581 2.376 2.401 1.653 3.315 0.498 0.000 0.000 10.996 NE 0.264 0.930 3.614 2.368 1.288 1.894 0.199 0.000 0.000 10.556 ENE 0.157 0.606 2.093 0.972 0.573 0.498 0.058 0.000 0.000 4.958 E 0.077 0.515 0.814 0.515 0.282 0.150 0.017 0.000 0.000 2.370 ESE 0.049 0.282 0.557 0.241 0.075 0.042 0.000 0.008 0.000 1.253 SE 0.033 0.183 0.390 0.332 0.116 0.174 0.150 0.066 0.000 1.445 SSE 0.068 0.216 0.955 0.557 0.191 0.557 0.432 0.033 0.000 3.009 S 0.111 0.449 1.462 1.213 0.706 1.205 0.831 0.316 0.058 6.349 SSW 0.128 0.432 1.778 2.725 2.475 5.076 3.780 0.972 0.058 17.423 SW 0.089 0.349 1.180 1.570 1.886 3.157 1.595 0.307 0.042 10.173 WSW 0.056 0.282 0.689 0.714 0.565 0.905 0.515 0.125 0.017 3.869 W 0.051 0.316 0.565 0.407 0.341 1.097 0.640 0.075 0.025 3.515 WNW 0.040 0.249 0.432 0.474 0.507 1.545 0.764 0.083 0.017 4.110 NW 0.054 0.324 0.606 0.557 0.822 2.019 0.756 0.066 0.008 5.213 NNW 0.050 0.241 0.615 0.565 0.872 2.093 0.989 0.058 0.008 5.491 SUBTOTAL 1.504 6.405 19.505 16.855 13.698 27.604 12.020 2.176 0.233 100.000 Total Hours Of Valid Wind Observations 12038 Total Hours Of Observations 12648 Recoverability Percentage 95.2 Total Hours Calm 181 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 7.13 2.3-51 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-23 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant April (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.074 0.651 0.984 1.281 1.230 1.476 0.130 0.000 0.000 5.828 NNE 0.075 0.528 1.129 1.788 1.621 2.128 0.181 0.000 0.000 7.450 NE 0.113 0.832 1.657 1.100 1.013 0.738 0.022 0.000 0.000 5.476 ENE 0.168 1.223 2.468 0.970 0.528 0.232 0.000 0.000 0.000 5.588 E 0.122 1.122 1.563 0.767 0.224 0.058 0.000 0.000 0.000 3.856 ESE 0.056 0.608 0.630 0.355 0.022 0.007 0.000 0.000 0.000 1.677 SE 0.059 0.695 0.601 0.391 0.145 0.043 0.000 0.000 0.000 1.933 SSE 0.101 0.782 1.433 0.796 0.275 0.297 0.145 0.007 0.000 3.835 S 0.134 1.136 1.816 1.592 0.905 1.100 0.579 0.094 0.000 7.356 SSW 0.178 1.028 2.888 3.495 3.597 5.797 1.578 0.282 0.000 18.842 SW 0.166 1.389 2.258 1.534 0.890 0.695 0.174 0.036 0.000 7.142 WSW 0.177 1.918 1.976 0.789 0.420 0.536 0.159 0.014 0.000 5.988 W 0.160 1.744 1.773 0.745 0.644 1.020 0.232 0.007 0.000 6.326 WNW 0.126 1.585 1.201 0.709 0.637 1.426 0.224 0.000 0.000 5.909 NW 0.152 1.715 1.643 0.832 0.825 1.744 0.232 0.007 0.000 7.151 NNW 0.101 1.078 1.158 0.876 0.861 1.462 0.109 0.000 0.000 5.645 SUBTOTAL 1.961 18.034 25.177 18.020 13.837 18.758 3.763 0.449 0.000 100.000 Total Hours Of Valid Wind Observations 13818 Total Hours Of Observations 14400 Recoverability Percentage 96.0 Total Hours Calm 271 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 4.87 2.3-52 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-24 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant April (77-93)

Wind Wind Speed (MPH) Wind Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.087 0.401 0.959 0.820 0.968 2.467 0.462 0.009 0.000 6.173 NNE 0.157 0.706 1.735 1.656 1.674 2.642 0.645 0.009 0.000 9.224 NE 0.228 0.846 2.711 1.500 1.177 1.447 0.209 0.000 0.000 8.118 ENE 0.192 0.750 2.241 0.942 0.619 0.514 0.009 0.000 0.000 5.266 E 0.075 0.392 0.776 0.488 0.288 0.227 0.009 0.000 0.000 2.255 ESE 0.047 0.262 0.471 0.340 0.139 0.026 0.000 0.000 0.000 1.285 SE 0.045 0.218 0.480 0.384 0.174 0.166 0.017 0.000 0.000 1.483 SSE 0.092 0.453 0.985 0.820 0.323 0.480 0.253 0.087 0.000 3.493 S 0.158 0.584 1.883 1.691 1.055 1.107 0.575 0.288 0.070 7.412 SSW 0.198 0.610 2.467 3.470 3.862 6.164 3.662 0.828 0.157 21.418 SW 0.119 0.418 1.439 1.953 1.883 3.025 1.412 0.314 0.052 10.616 WSW 0.075 0.340 0.828 0.750 0.671 1.142 0.567 0.192 0.061 4.626 W 0.065 0.384 0.636 0.584 0.471 1.194 0.645 0.070 0.017 4.067 WNW 0.044 0.305 0.384 0.453 0.453 1.857 1.020 0.052 0.000 4.569 NW 0.058 0.279 0.619 0.549 1.003 2.014 0.610 0.087 0.000 5.219 NNW 0.050 0.279 0.506 0.567 0.689 1.901 0.750 0.035 0.000 4.776 SUBTOTAL 1.691 7.228 19.119 16.966 15.449 26.373 10.846 1.970 0.357 100.000 Total Hours Of Valid Wind Observations 11470 Total Hours Of Observations 12240 Recoverability Percentage 93.7 Total Hours Calm 194 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 6.93 2.3-53 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-25 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant May (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.109 0.618 1.237 1.606 1.293 1.208 0.050 0.000 0.000 6.121 NNE 0.099 0.426 1.265 1.748 1.571 1.606 0.057 0.000 0.000 6.773 NE 0.143 0.633 1.798 1.883 1.094 0.796 0.000 0.000 0.000 6.347 ENE 0.225 0.988 2.836 1.407 0.682 0.284 0.007 0.000 0.000 6.429 E 0.183 1.329 1.791 0.768 0.213 0.028 0.007 0.000 0.000 4.320 ESE 0.081 0.682 0.696 0.306 0.028 0.014 0.000 0.000 0.000 1.808 SE 0.117 0.931 1.066 0.583 0.142 0.057 0.000 0.000 0.000 2.896 SSE 0.178 1.237 1.791 0.725 0.156 0.156 0.014 0.000 0.000 4.257 S 0.256 1.315 3.042 2.168 1.080 0.874 0.178 0.000 0.000 8.912 SSW 0.327 1.578 3.980 4.307 3.440 3.397 0.448 0.007 0.000 17.482 SW 0.281 1.940 2.843 1.812 0.746 0.561 0.050 0.000 0.000 8.234 WSW 0.256 2.409 1.940 0.441 0.320 0.149 0.014 0.000 0.000 5.529 W 0.254 2.459 1.869 0.561 0.434 0.362 0.014 0.000 0.000 5.954 WNW 0.165 1.578 1.237 0.633 0.497 0.590 0.021 0.000 0.000 4.721 NW 0.211 1.940 1.656 0.540 0.441 0.696 0.014 0.000 0.000 5.499 NNW 0.149 1.222 1.308 0.760 0.505 0.739 0.036 0.000 0.000 4.718 SUBTOTAL 3.035 21.285 30.353 20.247 12.643 11.520 0.910 0.007 0.000 100.000 Total Hours Of Valid Wind Observations 14071 Total Hours Of Observations 14880 Recoverability Percentage 94.6 Total Hours Calm 427 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 3.87 2.3-54 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-26 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant May (77-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.114 0.504 1.123 1.098 1.245 2.099 0.382 0.016 0.000 6.581 NNE 0.220 0.944 2.213 1.912 1.757 2.253 0.366 0.000 0.000 9.665 NE 0.324 1.318 3.319 2.310 1.432 1.464 0.089 0.000 0.000 10.256 ENE 0.266 1.163 2.644 1.155 0.838 0.700 0.049 0.000 0.000 6.814 E 0.119 0.610 1.090 0.700 0.203 0.114 0.000 0.000 0.000 2.836 ESE 0.068 0.268 0.708 0.488 0.065 0.049 0.008 0.000 0.000 1.654 SE 0.080 0.325 0.822 0.439 0.203 0.220 0.000 0.000 0.000 2.089 SSE 0.141 0.635 1.383 0.797 0.212 0.260 0.081 0.016 0.000 3.525 S 0.241 0.748 2.709 2.017 1.131 1.180 0.374 0.065 0.000 8.465 SSW 0.296 0.822 3.425 4.417 3.474 5.255 2.595 0.456 0.016 20.755 SW 0.189 0.610 2.099 2.253 2.001 2.628 0.773 0.106 0.000 10.658 WSW 0.112 0.553 1.058 0.683 0.537 0.716 0.212 0.033 0.000 3.903 W 0.093 0.496 0.838 0.399 0.317 0.667 0.236 0.000 0.000 3.046 WNW 0.066 0.382 0.569 0.415 0.358 0.879 0.220 0.008 0.000 2.897 NW 0.072 0.366 0.659 0.439 0.447 0.968 0.268 0.000 0.000 3.220 NNW 0.081 0.415 0.740 0.578 0.635 0.984 0.187 0.016 0.000 3.635 SUBTOTAL 2.481 10.160 25.397 20.101 14.854 20.434 5.841 0.716 0.016 100.000 Total Hours Of Valid Wind Observations 12293 Total Hours Of Observations 12648 Recoverability Percentage 97.2 Total Hours Calm 305 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level 1-DEC-94 WBNP-101 Mean Wind Speed = 5.53 2.3-55 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-27 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant June (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.078 0.403 1.023 1.801 1.174 0.994 0.050 0.000 0.000 5.525 NNE 0.077 0.403 1.001 1.679 1.477 1.830 0.166 0.000 0.000 6.633 NE 0.097 0.454 1.304 1.304 0.627 0.483 0.000 0.000 0.000 4.268 ENE 0.185 0.850 2.521 1.527 0.490 0.137 0.007 0.000 0.000 5.718 E 0.158 1.102 1.765 0.605 0.173 0.014 0.000 0.000 0.000 3.817 ESE 0.068 0.605 0.627 0.180 0.050 0.029 0.007 0.000 0.000 1.566 SE 0.113 0.951 1.102 0.461 0.043 0.000 0.007 0.000 0.000 2.678 SSE 0.174 1.390 1.765 0.720 0.245 0.086 0.000 0.000 0.000 4.381 S 0.294 1.599 3.753 2.637 1.297 0.713 0.029 0.000 0.000 10.323 SSW 0.376 1.643 5.187 5.619 4.005 3.112 0.158 0.000 0.000 20.100 SW 0.319 2.305 3.487 2.183 1.001 0.317 0.007 0.000 0.000 9.619 WSW 0.265 2.377 2.449 0.483 0.202 0.072 0.000 0.000 0.000 5.849 W 0.218 2.240 1.722 0.555 0.382 0.195 0.014 0.000 0.000 5.326 WNW 0.185 1.844 1.520 0.569 0.612 0.418 0.007 0.000 0.000 5.156 NW 0.193 2.082 1.426 0.526 0.497 0.360 0.014 0.000 0.000 5.099 NNW 0.111 0.994 1.016 0.778 0.576 0.439 0.029 0.000 0.000 3.943 SUBTOTAL 2.910 21.245 31.669 21.627 12.852 9.200 0.497 0.000 0.000 100.000 Total Hours Of Valid Wind Observations 13381 Total Hours Of Observations 14400 Recoverability Percentage 96.4 Total Hours Calm 404 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 3.62 2.3-56 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-28 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant June (77-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.107 0.792 1.163 1.137 1.196 1.988 0.219 0.008 0.000 6.612 NNE 0.174 0.944 2.224 2.056 1.592 2.334 0.388 0.008 0.000 9.720 NE 0.231 1.340 2.881 1.938 1.053 0.994 0.017 0.008 0.000 8.463 ENE 0.195 1.078 2.477 1.331 0.767 0.447 0.008 0.000 0.000 6.303 E 0.109 0.784 1.213 0.615 0.261 0.126 0.000 0.000 0.000 3.109 ESE 0.054 0.371 0.615 0.329 0.076 0.034 0.000 0.008 0.000 1.486 SE 0.068 0.472 0.775 0.514 0.076 0.034 0.008 0.000 0.000 1.947 SSE 0.133 0.716 1.702 0.977 0.329 0.194 0.008 0.000 0.000 4.059 S 0.225 0.927 3.185 2.603 1.255 0.876 0.135 0.008 0.000 9.215 SSW 0.254 0.767 3.859 6.471 4.870 5.771 1.297 0.042 0.017 23.347 SW 0.149 0.725 1.997 2.898 2.182 2.755 0.480 0.008 0.000 11.195 WSW 0.091 0.463 1.188 0.893 0.371 0.615 0.110 0.000 0.000 3.730 W 0.066 0.463 0.741 0.379 0.354 0.607 0.051 0.017 0.000 2.678 WNW 0.065 0.573 0.615 0.396 0.404 0.767 0.051 0.000 0.000 2.871 NW 0.050 0.421 0.497 0.354 0.404 0.581 0.042 0.008 0.000 2.359 NNW 0.058 0.447 0.615 0.463 0.514 0.699 0.110 0.000 0.000 2.906 SUBTOTAL 2.030 11.281 25.748 23.355 15.705 18.822 2.924 0.118 0.017 100.000 Total Hours Of Valid Wind Observations 11869 Total Hours Of Observations 12240 Recoverability Percentage 97.0 Total Hours Calm 241 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 4.98 2.3-57 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-29 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant July (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.062 0.414 1.056 1.388 0.808 0.373 0.000 0.000 0.000 4.100 NNE 0.058 0.387 1.001 1.643 1.719 1.070 0.021 0.000 0.000 5.899 NE 0.068 0.373 1.243 1.747 1.084 0.366 0.014 0.000 0.000 4.893 ENE 0.126 0.656 2.347 1.574 0.614 0.138 0.000 0.000 0.000 5.456 E 0.118 1.049 1.760 0.884 0.166 0.055 0.000 0.000 0.000 4.032 ESE 0.060 0.518 0.918 0.394 0.055 0.000 0.000 0.000 0.000 1.945 SE 0.104 0.870 1.609 0.670 0.076 0.035 0.007 0.000 0.000 3.369 SSE 0.169 1.415 2.603 1.084 0.214 0.124 0.000 0.000 0.000 5.609 S 0.246 1.664 4.211 2.996 1.042 0.504 0.014 0.000 0.000 10.678 SSW 0.310 1.885 5.516 5.647 3.238 1.685 0.076 0.000 0.000 18.357 SW 0.268 2.168 4.225 1.843 0.683 0.249 0.000 0.000 0.000 9.436 WSW 0.223 2.575 2.748 0.587 0.193 0.069 0.000 0.000 0.000 6.395 W 0.182 2.154 2.195 0.580 0.338 0.200 0.000 0.000 0.000 5.650 WNW 0.158 1.899 1.878 0.663 0.373 0.166 0.007 0.000 0.000 5.143 NW 0.161 1.892 1.947 0.456 0.407 0.269 0.007 0.000 0.000 5.139 NNW 0.095 1.091 1.174 0.677 0.545 0.311 0.007 0.000 0.000 3.899 SUBTOTAL 2.409 21.008 36.431 22.831 11.557 5.613 0.152 0.000 0.000 100.000 Total Hours Of Valid Wind Observations 14485 Total Hours Of Observations 14880 Recoverability Percentage 97.3 Total Hours Calm 349 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 3.32 2.3-58 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-30 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant July (77-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.088 0.833 1.468 1.237 1.064 0.940 0.041 0.000 0.000 5.673 NNE 0.122 0.899 2.302 1.873 1.947 1.980 0.132 0.008 0.000 9.263 NE 0.161 1.279 2.929 2.062 1.477 0.973 0.016 0.000 0.000 8.897 ENE 0.120 0.883 2.252 1.526 0.982 0.429 0.025 0.000 0.000 6.216 E 0.071 0.602 1.262 0.800 0.363 0.074 0.000 0.000 0.000 3.173 ESE 0.034 0.256 0.635 0.462 0.132 0.066 0.000 0.000 0.000 1.585 SE 0.050 0.256 1.064 0.817 0.173 0.049 0.025 0.000 0.000 2.434 SSE 0.104 0.627 2.095 1.171 0.256 0.198 0.025 0.000 0.000 4.476 S 0.165 0.874 3.448 2.854 1.279 0.998 0.066 0.000 0.000 9.685 SSW 0.219 0.866 4.867 7.095 4.917 4.290 0.643 0.041 0.000 22.938 SW 0.120 0.544 2.607 3.003 2.079 1.881 0.355 0.008 0.000 10.597 WSW 0.059 0.610 0.940 0.932 0.610 0.544 0.099 0.008 0.000 3.804 W 0.051 0.470 0.874 0.652 0.437 0.454 0.082 0.000 0.000 3.021 WNW 0.042 0.478 0.610 0.346 0.412 0.553 0.025 0.008 0.000 2.475 NW 0.050 0.495 0.808 0.561 0.388 0.454 0.107 0.000 0.000 2.863 NNW 0.046 0.454 0.759 0.495 0.487 0.635 0.016 0.008 0.000 2.901 SUBTOTAL 1.501 10.427 28.923 25.887 17.002 14.519 1.658 0.082 0.000 100.000 Total Hours Of Valid Wind Observations 12122 Total Hours Of Observations 12648 Recoverability Percentage 95.8 Total Hours Calm 182 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 4.62 2.3-59 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-31 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant August (74-93)

Wind Wind Speed(MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.132 0.672 1.428 1.934 1.130 0.770 0.014 0.000 0.000 6.081 NNE 0.101 0.367 1.241 1.907 2.004 1.414 0.035 0.000 0.000 7.069 NE 0.153 0.471 1.955 1.913 0.887 0.492 0.007 0.000 0.000 5.879 ENE 0.278 0.915 3.494 2.045 0.499 0.250 0.000 0.000 0.000 7.481 E 0.185 1.109 1.823 0.991 0.139 0.049 0.000 0.000 0.000 4.296 ESE 0.080 0.499 0.776 0.354 0.014 0.014 0.000 0.000 0.000 1.737 SE 0.120 0.749 1.165 0.506 0.125 0.090 0.000 0.000 0.000 2.755 SSE 0.226 1.199 2.392 1.026 0.277 0.111 0.000 0.000 0.000 5.232 S 0.349 1.754 3.792 2.940 1.075 0.603 0.007 0.000 0.000 10.520 SSW 0.409 1.865 4.638 4.368 2.662 1.456 0.021 0.000 0.000 15.419 SW 0.342 2.156 3.279 1.220 0.263 0.069 0.000 0.000 0.000 7.330 WSW 0.310 2.558 2.371 0.395 0.076 0.007 0.000 0.000 0.000 5.718 W 0.258 2.385 1.712 0.333 0.187 0.014 0.000 0.000 0.000 4.889 WNW 0.242 2.302 1.539 0.444 0.153 0.076 0.000 0.000 0.000 4.755 NW 0.307 2.808 2.073 0.451 0.257 0.097 0.007 0.000 0.000 5.999 NNW 0.189 1.359 1.636 0.638 0.624 0.381 0.014 0.000 0.000 4.840 SUBTOTAL 3.681 23.170 35.316 21.464 10.372 5.893 0.104 0.000 0.000 100.000 Total Hours Of Valid Wind Observations 14424 Total Hours Of Observations 14880 Recoverability Percentage 96.9 Total Hours Calm 531 Meteorological Facility: Watts Bar Nuclear Plant Date Printed: 1-DEC-94 Wind Speed And Direction Measured At 9.72 Meter Level WBNP-101 Mean Wind Speed = 3.20 2.3-60 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-32 98Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant August (77-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.134 0.737 1.483 1.424 1.206 1.625 0.142 0.000 0.000 6.752 NNE 0.241 1.131 2.848 2.161 2.111 2.186 0.109 0.008 0.000 10.796 NE 0.346 1.474 4.247 2.622 1.659 0.963 0.067 0.000 0.000 11.379 ENE 0.275 1.332 3.209 2.237 0.888 0.511 0.050 0.000 0.000 8.501 E 0.140 0.972 1.349 0.880 0.285 0.151 0.008 0.000 0.000 3.784 ESE 0.077 0.528 0.746 0.578 0.101 0.059 0.008 0.000 0.000 2.096 SE 0.086 0.461 0.955 0.570 0.159 0.151 0.008 0.000 0.000 2.389 SSE 0.153 0.737 1.784 1.081 0.402 0.226 0.017 0.000 0.000 4.400 S 0.277 1.072 3.502 2.957 1.198 0.871 0.042 0.000 0.000 9.919 SSW 0.356 1.014 4.867 5.831 4.071 3.301 0.352 0.008 0.000 19.799 SW 0.191 0.771 2.379 2.212 1.374 0.930 0.117 0.000 0.000 7.973 WSW 0.088 0.486 0.963 0.670 0.218 0.193 0.025 0.000 0.000 2.643 W 0.069 0.461 0.679 0.302 0.159 0.201 0.008 0.000 0.000 1.878 WNW 0.066 0.394 0.704 0.352 0.209 0.226 0.025 0.000 0.000 1.976 NW 0.086 0.528 0.888 0.352 0.268 0.285 0.084 0.000 0.000 2.490 NNW 0.082 0.519 0.829 0.662 0.469 0.586 0.075 0.000 0.000 3.223 SUBTOTAL 2.664 12.616 31.432 24.889 14.778 12.465 1.139 0.017 0.000 100.000 Total Hours Of Valid Wind Observations 11937 Total Hours Of Observations 12648 Recoverability Percentage 94.4 Total Hours Calm 318 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 4.24 2.3-61 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-33 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant September (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.188 0.890 1.780 2.091 1.664 1.158 0.029 0.000 0.000 7.800 NNE 0.155 0.550 1.657 2.554 2.352 3.169 0.130 0.000 0.000 10.567 NE 0.186 0.601 2.048 2.677 1.368 0.984 0.022 0.007 0.000 7.892 ENE 0.274 0.999 2.902 1.512 0.347 0.145 0.000 0.000 0.000 6.178 E 0.166 0.818 1.548 0.695 0.080 0.036 0.000 0.000 0.000 3.343 ESE 0.059 0.268 0.579 0.159 0.022 0.022 0.000 0.000 0.000 1.109 SE 0.088 0.391 0.861 0.224 0.072 0.014 0.014 0.000 0.000 1.665 SSE 0.171 0.912 1.520 0.651 0.174 0.058 0.000 0.000 0.000 3.485 S 0.307 1.397 2.981 2.113 1.143 0.767 0.029 0.000 0.000 8.737 SSW 0.348 1.418 3.531 3.944 2.598 1.382 0.058 0.000 0.000 13.278 SW 0.281 1.737 2.265 1.165 0.355 0.072 0.000 0.000 0.000 5.874 WSW 0.271 2.178 1.686 0.326 0.065 0.014 0.000 0.000 0.000 4.541 W 0.290 2.489 1.643 0.326 0.195 0.072 0.000 0.000 0.000 5.015 WNW 0.327 2.967 1.693 0.470 0.268 0.166 0.000 0.000 0.000 5.892 NW 0.430 3.813 2.315 0.535 0.434 0.355 0.000 0.000 0.000 7.883 NNW 0.278 2.055 1.903 1.035 0.673 0.796 0.000 0.000 0.000 6.740 SUBTOTAL 3.821 23.480 30.912 20.478 11.809 9.211 0.282 0.007 0.000 100.000 Total Hours Of Valid Wind Observations 13820 Total Hours Of Observations 14400 Recoverability Percentage 96.0 Total Hours Calm 528 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 3.51 2.3-62 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-34 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant September (77-93)

Wind Wind Speed(MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.129 0.604 1.261 1.501 1.403 2.646 0.169 0.000 0.000 7.712 NNE 0.256 0.968 2.744 2.753 2.690 3.871 0.657 0.018 0.000 13.957 NE 0.388 1.545 4.067 3.312 2.060 2.131 0.240 0.018 0.000 13.760 ENE 0.299 1.438 2.895 1.598 0.666 0.444 0.027 0.000 0.000 7.367 E 0.148 1.128 1.012 0.426 0.186 0.044 0.000 0.000 0.000 2.945 ESE 0.089 0.613 0.675 0.364 0.053 0.036 0.009 0.000 0.000 1.838 SE 0.094 0.586 0.781 0.249 0.080 0.062 0.027 0.009 0.000 1.888 SSE 0.169 0.844 1.607 0.915 0.275 0.231 0.000 0.000 0.000 4.041 S 0.277 1.083 2.930 2.060 0.861 1.048 0.124 0.009 0.000 8.393 SSW 0.336 1.243 3.623 4.466 3.570 3.818 0.719 0.062 0.000 17.838 SW 0.169 0.790 1.652 1.900 1.438 1.279 0.044 0.000 0.000 7.272 WSW 0.104 0.488 1.021 0.551 0.240 0.195 0.018 0.000 0.000 2.617 W 0.072 0.462 0.577 0.329 0.222 0.240 0.044 0.000 0.000 1.945 WNW 0.074 0.417 0.657 0.284 0.204 0.479 0.044 0.000 0.000 2.161 NW 0.080 0.444 0.710 0.364 0.293 0.657 0.036 0.000 0.000 2.584 NNW 0.085 0.506 0.719 0.586 0.648 1.021 0.115 0.000 0.000 3.681 SUBTOTAL 2.770 13.159 26.931 21.657 14.891 18.203 2.273 0.115 0.000 100.000 Total Hours Of Valid Wind Observations 11262 Total Hours Of Observations 12240 Recoverability Percentage 92.0 Total Hours Calm 312 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 4.74 2.3-63 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-35 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant October (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.269 1.027 1.805 1.861 1.937 2.055 0.049 0.000 0.000 9.002 NNE 0.225 0.847 1.527 2.194 1.923 2.298 0.146 0.000 0.000 9.160 NE 0.262 0.798 1.965 1.937 1.222 0.757 0.000 0.000 0.000 6.941 ENE 0.374 1.326 2.617 1.222 0.340 0.118 0.000 0.000 0.000 5.998 E 0.195 0.909 1.146 0.396 0.111 0.076 0.000 0.000 0.000 2.833 ESE 0.069 0.389 0.333 0.083 0.000 0.021 0.000 0.000 0.000 0.895 SE 0.103 0.562 0.528 0.118 0.049 0.028 0.000 0.000 0.000 1.388 SSE 0.197 0.757 1.319 0.292 0.160 0.069 0.021 0.000 0.000 2.814 S 0.333 1.125 2.388 1.673 0.833 0.639 0.062 0.000 0.000 7.054 SSW 0.369 1.083 2.805 3.076 2.312 2.083 0.153 0.000 0.000 11.880 SW 0.308 1.354 1.888 1.062 0.444 0.194 0.007 0.000 0.000 5.258 WSW 0.383 2.083 1.958 0.458 0.208 0.104 0.007 0.000 0.000 5.202 W 0.472 3.082 1.895 0.410 0.299 0.368 0.000 0.000 0.000 6.526 WNW 0.510 3.686 1.687 0.673 0.569 0.660 0.021 0.000 0.000 7.806 NW 0.696 4.638 2.701 0.660 0.576 0.618 0.035 0.000 0.000 9.923 NNW 0.350 1.993 1.701 1.125 0.868 1.264 0.021 0.000 0.000 7.321 SUBTOTAL 5.117 25.660 28.263 17.238 11.851 11.351 0.521 0.000 0.000 100.000 Total Hours Of Valid Wind Observations 14404 Total Hours Of Observations 14880 Recoverability Percentage 96.8 Total Hours Calm 737 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 3.56 2.3-64 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-36 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant October (77-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.163 0.562 1.221 1.025 1.660 3.768 0.602 0.000 0.000 9.002 NNE 0.317 0.855 2.613 2.450 2.197 2.962 0.285 0.000 0.000 11.679 NE 0.487 1.595 3.728 2.588 1.628 1.717 0.065 0.000 0.000 11.808 ENE 0.456 1.579 3.410 1.001 0.619 0.236 0.024 0.000 0.000 7.325 E 0.235 1.514 1.058 0.350 0.163 0.090 0.016 0.000 0.000 3.426 ESE 0.118 0.863 0.431 0.163 0.016 0.000 0.000 0.000 0.000 1.591 SE 0.119 0.724 0.578 0.195 0.049 0.057 0.008 0.000 0.000 1.731 SSE 0.207 0.944 1.318 0.480 0.155 0.244 0.057 0.000 0.000 3.406 S 0.328 1.164 2.417 1.587 0.798 0.822 0.252 0.033 0.000 7.400 SSW 0.410 1.017 3.467 3.996 3.280 3.841 1.465 0.098 0.000 17.575 SW 0.241 0.830 1.807 1.620 1.367 1.563 0.358 0.024 0.000 7.810 WSW 0.138 0.570 0.944 0.619 0.415 0.464 0.138 0.000 0.000 3.288 W 0.132 0.610 0.830 0.244 0.277 0.570 0.179 0.000 0.000 2.842 WNW 0.082 0.366 0.529 0.350 0.439 1.213 0.317 0.008 0.000 3.305 NW 0.098 0.480 0.586 0.383 0.578 1.099 0.179 0.000 0.000 3.402 NNW 0.089 0.399 0.578 0.521 0.676 1.701 0.439 0.008 0.000 4.411 Subtotal 3.622 14.072 25.515 17.571 14.316 20.347 4.387 0.171 0.000 100.000 Total Hours Of Valid Wind Observations 12287 Total Hours Of Observations 12648 Recoverability Percentage 97.1 Total Hours Calm 445 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 5.03 2.3-65 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-37 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant November (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.190 1.041 1.378 1.636 1.493 1.737 0.151 0.000 0.000 7.626 NNE 0.241 1.091 1.974 2.261 2.153 2.089 0.072 0.000 0.000 9.880 NE 0.254 0.969 2.268 1.694 1.062 0.488 0.007 0.000 0.000 6.743 ENE 0.329 1.292 2.892 0.976 0.179 0.043 0.000 0.000 0.000 5.712 E 0.190 1.019 1.400 0.359 0.014 0.007 0.000 0.000 0.000 2.989 ESE 0.058 0.366 0.366 0.065 0.000 0.007 0.000 0.000 0.000 0.861 SE 0.071 0.402 0.495 0.136 0.050 0.065 0.029 0.000 0.000 1.248 SSE 0.114 0.452 0.998 0.416 0.108 0.194 0.043 0.000 0.000 2.325 S 0.228 0.746 2.153 1.199 0.660 0.761 0.230 0.000 0.000 5.977 SSW 0.289 0.804 2.871 3.560 2.727 3.223 0.646 0.036 0.000 14.155 SW 0.242 1.077 2.002 1.170 0.782 0.323 0.043 0.000 0.000 5.639 WSW 0.305 1.644 2.239 0.754 0.452 0.416 0.065 0.000 0.000 5.875 W 0.368 2.476 2.203 0.739 0.725 0.897 0.036 0.000 0.000 7.445 WNW 0.359 2.792 1.773 0.545 0.560 0.775 0.072 0.000 0.000 6.876 NW 0.425 3.172 2.239 1.019 0.883 1.041 0.086 0.000 0.000 8.866 NNW 0.278 1.931 1.601 1.234 1.191 1.471 0.079 0.000 0.000 7.785 SUBTOTAL 3.940 21.273 28.852 17.764 13.041 13.536 1.557 0.036 0.000 100.000 Total Hours Of Valid Wind Observations 13933 Total Hours Of Observations 14400 Recoverability Percentage 96.8 Total Hours Calm 549 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 3.99 2.3-66 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-38 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant November (77-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.116 0.573 1.306 1.096 1.290 3.253 0.725 0.034 0.000 8.392 NNE 0.201 0.952 2.309 2.056 2.309 2.857 0.396 0.008 0.000 11.090 NE 0.326 1.180 4.121 2.756 1.787 1.795 0.126 0.000 0.000 12.092 ENE 0.273 1.180 3.253 1.129 0.497 0.160 0.000 0.000 0.000 6.493 E 0.133 0.944 1.222 0.270 0.084 0.000 0.000 0.000 0.000 2.653 ESE 0.054 0.548 0.337 0.067 0.008 0.000 0.000 0.000 0.000 1.015 SE 0.062 0.514 0.489 0.143 0.067 0.093 0.025 0.000 0.000 1.393 SSE 0.104 0.531 1.155 0.320 0.160 0.253 0.160 0.042 0.000 2.725 S 0.187 0.725 2.318 1.306 0.750 0.809 0.539 0.126 0.000 6.761 SSW 0.227 0.716 2.967 3.767 2.958 4.560 2.200 0.371 0.017 17.782 SW 0.142 0.641 1.660 1.896 1.433 2.158 0.725 0.051 0.008 8.713 WSW 0.102 0.405 1.256 0.767 0.615 0.818 0.464 0.110 0.008 4.544 W 0.072 0.489 0.674 0.379 0.430 1.037 0.346 0.017 0.000 3.443 WNW 0.052 0.346 0.506 0.430 0.379 1.155 0.396 0.000 0.000 3.264 NW 0.073 0.455 0.733 0.506 0.573 1.525 0.303 0.000 0.000 4.169 NNW 0.085 0.455 0.927 0.716 0.784 2.014 0.480 0.008 0.000 5.471 Subtotal 2.208 10.653 25.234 17.606 14.126 22.486 6.886 0.767 0.034 100.000 Total Hours Of Valid Wind Observations 11865 Total Hours Of Observations 12240 Recoverability Percentage 96.9 Total Hours Calm 262 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 5.73 2.3-67 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-39 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant December (74-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.098 0.759 1.390 1.511 1.709 2.390 0.071 0.000 0.000 7.928 NNE 0.110 0.752 1.667 2.050 2.064 2.411 0.170 0.000 0.000 9.223 NE 0.144 0.929 2.234 1.766 0.950 0.709 0.007 0.000 0.000 6.740 ENE 0.187 1.106 3.014 0.908 0.199 0.035 0.000 0.000 0.000 5.450 E 0.090 0.851 1.135 0.177 0.028 0.000 0.007 0.000 0.000 2.289 ESE 0.025 0.270 0.270 0.021 0.000 0.000 0.000 0.000 0.000 0.585 SE 0.043 0.355 0.589 0.106 0.021 0.014 0.007 0.000 0.000 1.135 SSE 0.092 0.745 1.277 0.227 0.050 0.057 0.028 0.000 0.000 2.475 S 0.133 0.674 2.241 1.312 0.546 0.504 0.277 0.035 0.000 5.721 SSW 0.167 0.816 2.851 4.163 3.206 3.667 0.539 0.121 0.000 15.528 SW 0.149 1.014 2.262 1.511 0.908 0.511 0.078 0.000 0.000 6.433 WSW 0.174 1.475 2.362 0.858 0.539 0.355 0.064 0.000 0.000 5.827 W 0.191 1.915 2.277 0.979 0.865 1.128 0.099 0.000 0.000 7.453 WNW 0.169 2.085 1.638 0.610 0.858 1.213 0.121 0.007 0.000 6.701 NW 0.234 2.426 2.709 0.965 0.943 1.603 0.156 0.000 0.000 9.035 NNW 0.144 1.496 1.674 0.957 1.248 1.787 0.170 0.000 0.000 7.477 Subtotal 2.149 17.667 29.589 18.121 14.135 16.383 1.794 0.163 0.000 100.000 Total Hours Of Valid Wind Observations 14100 Total Hours Of Observations 14880 Recoverability Percentage 94.8 Total Hours Calm 303 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 4.39 2.3-68 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-40 Joint Percentage Frequencies Of Wind Speed By Wind Direction Disregarding Stability Class, Watts Bar Nuclear Plant December (77-93)

Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.074 0.514 1.128 1.169 1.186 3.973 0.836 0.058 0.000 8.940 NNE 0.112 0.506 1.982 2.281 2.206 3.658 0.547 0.033 0.000 11.325 NE 0.158 0.763 2.762 2.621 1.841 1.650 0.174 0.000 0.000 9.970 ENE 0.127 0.647 2.190 0.887 0.431 0.166 0.000 0.000 0.000 4.448 E 0.068 0.713 0.796 0.199 0.033 0.000 0.008 0.000 0.000 1.818 ESE 0.039 0.456 0.423 0.066 0.008 0.000 0.000 0.000 0.000 0.993 SE 0.037 0.315 0.514 0.116 0.025 0.025 0.017 0.008 0.000 1.057 SSE 0.068 0.506 1.004 0.274 0.083 0.116 0.033 0.008 0.000 2.091 S 0.135 0.639 2.364 1.178 0.605 0.547 0.299 0.100 0.800 5.874 SSW 0.178 0.713 3.260 4.023 3.243 4.462 2.604 0.489 0.041 19.014 SW 0.103 0.498 1.800 2.015 1.825 3.351 0.896 0.124 0.017 10.628 WSW 0.068 0.456 1.053 0.846 0.705 1.037 0.340 0.075 0.017 4.596 W 0.050 0.365 0.738 0.547 0.481 1.286 0.340 0.041 0.000 3.848 WNW 0.049 0.481 0.605 0.406 0.506 1.858 0.722 0.066 0.000 4.693 NW 0.043 0.365 0.589 0.597 0.763 2.007 0.647 0.050 0.008 5.069 NNW 0.044 0.307 0.672 0.705 0.763 2.331 0.763 0.050 0.000 5.634 Subtotal 1.352 8.244 21.879 17.931 14.705 26.466 8.228 1.103 0.091 100.000 Total Hours Of Valid Wind Observations 12057 Total Hours Of Observations 12648 Recoverability Percentage 95.3 Total Hours Calm 163 Meteorological Facility: Watts Bar Nuclear Plant Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 1-DEC-94 WBNP-101 Mean Wind Speed = 6.36 2.3-69 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

WATTS BAR WBNP-101 THIS PAGE IS INTENTIONALLY LEFT BLANK 2.3-70 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-41 Percent Occurrence Of Wind Speed*

For All Wind Directions July 1, 1971 - June 28, 1972 Annual Wind Wind Speed (MPH)**

Direction 1-3 4-7 8-12 13-18 > 19 Total N 4.33 1.07 0.14 0.03 - 5.57 NNE 4.16 2.11 0.29 0.01 - 6.57 NE 5.26 4.12 0.49 - - 9.87 ENE 3.9 2.07 0.23 0.01 - 6.21 E 1.64 0.5 0.04 - - 2.18 ESE 1.11 0.45 0.25 - - 1.81 SE 1.72 0.5 0.33 - - 2.55 SSE 2.27 0.81 0.16 - - 3.24 S 2.94 2.83 0.68 0.15 - 6.6 SSW 2.54 4.69 1.8 0.33 - 9.36 SW 2.54 3.08 0.62 0.04 - 6.28 WSW 2.07 1.08 0.2 0.03 - 3.38 W 2.18 1.26 1.02 0.09 - 4.55 WNW 2.38 1.21 0.9 0.01 - 4.5 NW 4.97 1.74 0.73 0.06 - 7.5 NNW 5.71 2.13 0.29 0.05 - 8.18 Total 49.72 29.65 8.17 0.81 - 88.35 Calm = 11.64 All columns and calm total 100 percent of net valid observations, which represent 91 percent of total record.

Watts Bar temporary meteorological facility. Wind instruments 10 meters aboveground.

- Wind speed class 1-3 mph includes values 0.6-3.5 mph; class 4-7 mph includes values 3.6-7.5 mph; etc.

METEOROLOGY 2.3-71

2.3-72 WATTS BAR Table 2.3-42 Percent Occurrences Of Inversion Conditions And Pasquill Stability Classes A-G*

Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 STABILITY CLASS INVERSIONS A B C D E F G JANUARY 31.0 2.2 2.2 4.5 47.0 26.5 11.5 6.1 FEBRUARY 34.3 3.7 3.6 5.4 42.5 23.3 11.9 9.5 MARCH 36.3 5.4 4.1 6.1 37.5 23.7 11.9 11.3 APRIL 39.9 5.2 4.2 7.3 33.0 22.6 13.2 14.5 MAY 40.3 4.4 4.1 7.1 33.3 26.2 16.8 8.1 JUNE 40.7 5.6 4.7 7.9 30.9 27.3 17.6 5.9 JULY 39.6 5.8 4.5 7.9 31.5 29.4 16.5 4.6 AUGUST 40.7 5.0 4.4 7.2 30.8 32.5 17.0 3.0 SEPTEMBER 40.7 5.0 4.2 6.6 31.8 30.9 17.4 4.0 OCTOBER 44.3 4.3 3.9 6.3 32.1 24.1 20.9 8.5 NOVEMBER 41.2 1.8 2.2 4.5 38.5 26.8 15.4 10.8 DECEMBER 36.1 1.6 1.8 4.6 44.0 27.1 13.6 7.3 ANNUAL 38.8 4.2 3.7 6.3 36.1 26.7 15.3 7.8

Inversion Conditions Distributed Within Total Hours With Valid Vertical Temperature Difference Data. Stability Classes Distributed Within Total Hours With Valid Wind Direction, Wind Speed, And Vertical Temperature Difference Data.

Meteorological Facility Located 0.8 Km Ssw Of Watts Bar Nuclear Plant. Temperature Difference Between 9.51 And 45.63 Meters And Wind Direction And Wind Speed At 9.72 Meter Level.

METEOROLOGY WBNP-101

WATTS BAR WBNP-101 Table 2.3-43 Deleted By Amendment 63 METEOROLOGY 2.3-73

2.3-74 WATTS BAR Table 2.3-44 Inversion Persistence Data Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 (Delta-T Given In Degrees Celsius) (Page 1 of 2)

DISREGARDING INVERSION E F G F AND G STRENGTH NO. HOURS 0.0<DELTA-T<=1.5 1.5<DELTA-T<=4.0 DELT A-T>4.0 DELT A-T>1.5 DELTA-T>0.0 2 2027 1091 527 377 842 3 993 728 337 309 549 4 709 597 302 312 393 5 483 530 286 286 349 6 340 513 189 305 314 7 224 399 159 299 271 8 151 291 103 307 277 9 94 220 118 350 270 10 72 164 89 399 298 11 64 132 87 477 419 12 42 60 53 414 773 13 19 31 40 357 731 14 10 17 34 213 595 15 7 3 6 168 468 16 4 1 2 50 272 17 1 0 0 8 98 18 0 0 0 1 25 19 0 1 0 2 8 20 0 0 0 1 0 21 0 0 0 1 1 22 0 0 0 0 0 23 0 0 0 0 0 24 0 0 0 0 0 25 0 0 0 0 0 26 0 0 0 0 0 27 0 0 0 0 0 28 0 0 0 0 0 29 0 0 0 0 0 METEOROLOGY 30 0 0 0 0 0 31 0 0 0 0 0 WBNP-101 32 0 0 0 0 0

>=32 0 0 0 0 2*

Table 2.3-44 Inversion Persistence Data 2.3-75 WATTS BAR Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 (Delta-T Given In Degrees Celsius) (Continued) (Page 2 of 2)

DISREGARDING INVERSION E F G F AND G STRENGTH NO. HOURS 0.0<DELTA-T<=1.5 1.5<DELTA-T<=4.0 DELT A-T>4.0 DELT A-T>1.5 DELTA-T>0.0 TOTAL 5420 4778 2332 4636 6955 Maximum Hours of Persistence 17 19 16 21 45 Meteorological Facility Located 0.8 Km SSW Of Watts Bar Nuclear Plant Temperature Instruments Located 45.63 And 9.51 Meters Above Ground

January 1982 and December 1989 METEOROLOGY WBNP-101

2.3-76 WATTS BAR Table 2.3-45 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class A (Delta T<=-1.9 C/100 M),

Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.000 0.001 0.008 0.021 0.036 0.060 0.003 0.000 0.000 0.129 NNE 0.000 0.001 0.012 0.054 0.074 0.141 0.004 0.000 0.000 0.285 NE 0.000 0.000 0.035 0.088 0.078 0.089 0.000 0.000 0.000 0.289 ENE 0.000 0.001 0.037 0.079 0.071 0.032 0.000 0.000 0.000 0.220 E 0.000 0.002 0.037 0.041 0.015 0.005 0.000 0.000 0.000 0.100 ESE 0.000 0.000 0.016 0.016 0.002 0.001 0.000 0.000 0.000 0.035 SE 0.000 0.001 0.021 0.027 0.005 0.001 0.001 0.000 0.000 0.055 SSE 0.000 0.001 0.042 0.055 0.020 0.013 0.002 0.000 0.000 0.133 S 0.000 0.002 0.058 0.139 0.127 0.129 0.018 0.001 0.000 0.473 SSW 0.000 0.001 0.046 0.257 0.476 0.743 0.113 0.005 0.000 1.639 SW 0.000 0.000 0.018 0.093 0.118 0.102 0.012 0.000 0.000 0.343 WSW 0.000 0.000 0.006 0.016 0.017 0.063 0.021 0.002 0.000 0.125 W 0.000 0.000 0.004 0.010 0.014 0.064 0.014 0.001 0.000 0.106 WNW 0.000 0.000 0.001 0.004 0.007 0.033 0.005 0.000 0.000 0.050 NW 0.000 0.000 0.003 0.005 0.010 0.029 0.006 0.000 0.000 0.052 NNW 0.000 0.001 0.007 0.021 0.035 0.057 0.011 0.000 0.000 0.131 SUBTOTAL 0.001 0.008 0.350 0.925 1.102 1.563 0.210 0.008 0.000 4.166 Total Hours Of Valid Stability Observations 167789 Total Hours Of Stability Class A 6970 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class A 6849 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 164406 Total Hours Calm 1 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters METEOROLOGY Wind Speed And Direction Measured At 9.72 Meter Level WBNP-101 Mean Wind Speed = 7.21 Date Printed: 20-SEP-94 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-46 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class B (-1.9< Delta T<=-1.7 C/100 M),

Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.000 0.000 0.021 0.055 0.052 0.080 0.007 0.000 0.000 0.213 NNE 0.000 0.001 0.040 0.108 0.112 0.186 0.012 0.000 0.000 0.458 NE 0.000 0.000 0.069 0.123 0.107 0.086 0.002 0.000 0.000 0.387 ENE 0.000 0.001 0.052 0.101 0.071 0.024 0.000 0.000 0.000 0.249 E 0.000 0.001 0.061 0.055 0.015 0.002 0.000 0.000 0.000 0.133 ESE 0.000 0.002 0.021 0.024 0.002 0.001 0.000 0.000 0.000 0.049 SE 0.000 0.000 0.030 0.028 0.003 0.002 0.001 0.000 0.000 0.064 SSE 0.000 0.001 0.046 0.046 0.013 0.005 0.000 0.000 0.000 0.111 S 0.000 0.001 0.052 0.128 0.077 0.054 0.012 0.002 0.000 0.326 SSW 0.000 0.000 0.068 0.211 0.289 0.238 0.046 0.003 0.000 0.855 SW 0.000 0.000 0.027 0.114 0.080 0.029 0.003 0.000 0.000 0.252 WSW 0.000 0.000 0.007 0.024 0.026 0.023 0.007 0.000 0.000 0.085 W 0.000 0.000 0.005 0.010 0.023 0.049 0.012 0.001 0.000 0.099 WNW 0.000 0.000 0.005 0.005 0.019 0.060 0.007 0.000 0.000 0.097 NW 0.000 0.000 0.007 0.013 0.023 0.063 0.005 0.001 0.000 0.112 NNW 0.000 0.000 0.008 0.027 0.033 0.081 0.010 0.001 0.000 0.161 Subtotal 0.000 0.006 0.519 1.072 0.944 0.982 0.123 0.007 0.000 3.654 Total Hours Of Valid Stability Observations 167789 Total Hours Of Stability Class B 6109 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class B 6007 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 166406 Total Hours Calm 0 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters Wind Speed And Direction Measured At 9.72 Meter Level WBNP-101 Mean Wind Speed = 6.38 Date Printed: 20-SEP-94 2.3-77 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

2.3-78 WATTS BAR Table 2.3-47 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class C (-1.7< Delta T<=-1.5 C/100 M),

Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.000 0.001 0.041 0.099 0.117 0.154 0.008 0.000 0.000 0.419 NNE 0.000 0.001 0.099 0.205 0.221 0.292 0.019 0.000 0.000 0.837 NE 0.000 0.002 0.130 0.234 0.163 0.128 0.001 0.000 0.000 0.658 ENE 0.000 0.001 0.117 0.172 0.082 0.027 0.001 0.000 0.000 0.400 E 0.000 0.004 0.101 0.126 0.022 0.005 0.001 0.000 0.000 0.258 ESE 0.000 0.002 0.041 0.040 0.004 0.000 0.000 0.000 0.000 0.088 SE 0.000 0.001 0.055 0.056 0.008 0.001 0.002 0.000 0.000 0.123 SSE 0.000 0.001 0.085 0.109 0.029 0.012 0.004 0.000 0.000 0.238 S 0.000 0.001 0.116 0.245 0.114 0.068 0.017 0.001 0.000 0.561 SSW 0.000 0.001 0.099 0.418 0.375 0.268 0.062 0.004 0.000 1.227 SW 0.000 0.001 0.049 0.193 0.103 0.036 0.007 0.000 0.000 0.388 WSW 0.000 0.001 0.021 0.057 0.037 0.023 0.009 0.000 0.000 0.148 W 0.000 0.001 0.018 0.027 0.050 0.060 0.011 0.002 0.000 0.169 WNW 0.000 0.000 0.011 0.022 0.038 0.113 0.018 0.000 0.000 0.201 NW 0.000 0.000 0.020 0.040 0.051 0.144 0.015 0.001 0.000 0.270 NNW 0.000 0.000 0.024 0.056 0.081 0.129 0.011 0.000 0.000 0.301 Subtotal 0.000 0.015 1.027 2.097 1.494 1.460 0.184 0.009 0.000 6.286 Total Hours Of Valid Stability Observations 167789 Total Hours Of Stability Class C 10556 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class C 10335 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 164406 Total Hours Calm 0 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters METEOROLOGY Wind Speed And Direction Measured At 9.72 Meter Level WBNP-101 Mean Wind Speed = 6.06 Date Printed: 20-SEP-94 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-48 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class D (-1.5< Delta T<=-0.5 C/100 M),

Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.005 0.046 0.502 0.875 0.967 1.190 0.046 0.000 0.000 3.631 NNE 0.006 0.043 0.584 1.226 1.348 1.457 0.063 0.000 0.000 4.728 NE 0.008 0.067 0.727 1.043 0.615 0.355 0.009 0.001 0.000 2.824 ENE 0.010 0.108 0.859 0.585 0.159 0.052 0.001 0.000 0.000 1.773 E 0.007 0.135 0.568 0.260 0.064 0.016 0.000 0.000 0.000 1.050 ESE 0.003 0.070 0.245 0.082 0.013 0.007 0.000 0.000 0.000 0.420 SE 0.005 0.078 0.378 0.151 0.029 0.023 0.007 0.000 0.000 0.670 SSE 0.007 0.130 0.591 0.256 0.052 0.046 0.018 0.002 0.000 1.102 S 0.011 0.133 0.991 0.816 0.339 0.294 0.100 0.011 0.001 2.697 SSW 0.014 0.106 1.259 1.837 1.071 1.119 0.246 0.021 0.000 5.671 SW 0.009 0.129 0.784 0.742 0.249 0.151 0.018 0.001 0.001 2.084 WSW 0.006 0.083 0.498 0.335 0.170 0.121 0.029 0.001 0.000 1.242 W 0.005 0.095 0.408 0.336 0.347 0.409 0.044 0.002 0.000 1.647 WNW 0.004 0.098 0.325 0.359 0.436 0.571 0.055 0.003 0.000 1.851 NW 0.004 0.080 0.341 0.398 0.530 0.748 0.069 0.001 0.000 2.171 NNW 0.004 0.048 0.369 0.526 0.626 0.903 0.047 0.000 0.000 2.523 SUBTOTAL 0.108 1.450 9.428 9.828 7.014 7.463 0.751 0.042 0.002 36.085 Total Hours Of Valid Stability Observations 167789 Total Hours Of Stability Class D 60302 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class D 59326 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 164406 Total Hours Calm 177 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters Wind Speed And Direction Measured At 9.72 Meter Level WBNP-101 Mean Wind Speed = 5.37 Date Printed: 20-SEP-94 Note: Totals And Subtotals Are Obtained From Unrounded Numbers 2.3-79

2.3-80 WATTS BAR Table 2.3-49 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class E (-0.5< Delta T<= 1.5 C/100 M),

Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.030 0.164 0.499 0.599 0.274 0.083 0.002 0.000 0.000 1.650 NNE 0.025 0.138 0.415 0.422 0.213 0.070 0.003 0.000 0.000 1.286 NE 0.030 0.156 0.513 0.266 0.088 0.030 0.000 0.000 0.000 1.085 ENE 0.057 0.280 0.988 0.290 0.040 0.009 0.001 0.000 0.000 1.663 E 0.034 0.304 0.461 0.083 0.016 0.010 0.001 0.000 0.000 0.910 ESE 0.013 0.148 0.147 0.028 0.007 0.002 0.001 0.000 0.000 0.347 SE 0.019 0.208 0.209 0.049 0.030 0.021 0.004 0.000 0.000 0.539 SSE 0.039 0.341 0.519 0.114 0.059 0.066 0.014 0.001 0.000 1.152 S 0.067 0.450 1.037 0.478 0.206 0.186 0.061 0.007 0.000 2.492 SSW 0.090 0.505 1.499 1.117 0.743 0.751 0.148 0.016 0.000 4.869 SW 0.071 0.566 1.008 0.300 0.176 0.131 0.021 0.002 0.000 2.274 WSW 0.063 0.651 0.764 0.178 0.106 0.071 0.010 0.001 0.000 1.844 W 0.059 0.671 0.645 0.222 0.111 0.067 0.008 0.000 0.000 1.783 WNW 0.055 0.626 0.595 0.214 0.091 0.037 0.002 0.001 0.000 1.622 NW 0.059 0.652 0.664 0.256 0.111 0.049 0.002 0.000 0.000 1.793 NNW 0.039 0.349 0.512 0.308 0.146 0.075 0.002 0.000 0.000 1.430 SUBTOTAL 0.748 6.208 10.478 4.925 2.415 1.658 0.280 0.028 0.000 26.739 Total Hours Of Valid Stability Observations 167789 Total Hours Of Stability Class E 44969 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class E 43961 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 164406 Total Hours Calm 1229 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters METEOROLOGY Wind Speed And Direction Measured At 9.72 Meter Level WBNP-101 Mean Wind Speed = 3.28 Date Printed: 20-SEP-94 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-50 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class F ( 1.5< Delta T<= 4.0 C/100 M),

Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.051 0.288 0.245 0.027 0.006 0.001 0.000 0.000 0.000 0.617 NNE 0.043 0.229 0.219 0.027 0.001 0.001 0.000 0.000 0.000 0.519 NE 0.054 0.246 0.318 0.025 0.002 0.001 0.000 0.000 0.000 0.645 ENE 0.087 0.345 0.567 0.058 0.002 0.002 0.000 0.000 0.000 1.062 E 0.046 0.286 0.200 0.010 0.001 0.001 0.000 0.000 0.000 0.544 ESE 0.016 0.120 0.048 0.001 0.000 0.000 0.000 0.000 0.000 0.185 SE 0.023 0.159 0.082 0.005 0.001 0.000 0.000 0.000 0.000 0.270 SSE 0.042 0.254 0.189 0.018 0.002 0.002 0.000 0.000 0.000 0.508 S 0.061 0.338 0.304 0.040 0.005 0.004 0.000 0.000 0.000 0.751 SSW 0.078 0.387 0.435 0.175 0.063 0.013 0.000 0.000 0.000 1.151 SW 0.096 0.517 0.498 0.064 0.018 0.005 0.001 0.000 0.000 1.199 WSW 0.126 0.738 0.588 0.038 0.007 0.001 0.000 0.000 0.000 1.497 W 0.131 0.884 0.499 0.028 0.001 0.001 0.000 0.000 0.000 1.544 WNW 0.126 0.937 0.393 0.024 0.002 0.001 0.000 0.000 0.000 1.483 NW 0.184 1.225 0.707 0.041 0.004 0.002 0.001 0.000 0.000 2.163 NNW 0.099 0.644 0.398 0.030 0.004 0.000 0.000 0.000 0.000 1.175 SUBTOTAL 1.262 7.598 5.688 0.609 0.119 0.035 0.002 0.000 0.000 15.311 Total Hours Of Valid Stability Observations 166789 Total Hours Of Stability Class F 25805 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class F 25173 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 164406 Total Hours Calm 2075 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 and 45.63 Meters Wind Speed And Direction Measured At 9.72 Meter Level WBNP-101 Mean Wind Speed = 1.53 Date Printed: 20-SEP-94 NOTE: Totals And Subtotals Are Obtained From Unrounded Numbers 2.3-81

2.3-82 WATTS BAR Table 2.3-51 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class G (Delta T > 4.0 C/100 M),

Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.034 0.195 0.066 0.001 0.000 0.000 0.000 0.000 0.000 0.296 NNE 0.038 0.196 0.095 0.002 0.000 0.000 0.000 0.000 0.000 0.331 NE 0.054 0.257 0.161 0.001 0.000 0.000 0.000 0.000 0.000 0.473 ENE 0.091 0.376 0.327 0.008 0.000 0.001 0.000 0.000 0.000 0.803 E 0.047 0.257 0.105 0.002 0.000 0.000 0.000 0.000 0.000 0.410 ESE 0.015 0.095 0.024 0.000 0.000 0.000 0.000 0.000 0.000 0.135 SE 0.027 0.159 0.049 0.000 0.000 0.000 0.000 0.000 0.000 0.235 SSE 0.031 0.176 0.065 0.002 0.000 0.000 0.000 0.000 0.000 0.274 S 0.035 0.192 0.075 0.005 0.002 0.000 0.000 0.000 0.000 0.308 SSW 0.042 0.217 0.107 0.012 0.002 0.000 0.000 0.000 0.000 0.379 SW 0.053 0.278 0.130 0.005 0.000 0.000 0.000 0.000 0.000 0.466 WSW 0.089 0.436 0.251 0.007 0.000 0.000 0.000 0.000 0.000 0.782 W 0.094 0.464 0.260 0.005 0.000 0.000 0.000 0.000 0.000 0.823 WNW 0.075 0.406 0.172 0.004 0.000 0.000 0.000 0.000 0.000 0.656 NW 0.101 0.517 0.264 0.010 0.001 0.000 0.000 0.000 0.000 0.893 NNW 0.056 0.306 0.128 0.003 0.000 0.000 0.000 0.000 0.000 0.494 SUBTOTAL 0.881 4.525 2.280 0.068 0.004 0.001 0.000 0.000 0.000 7.758 Total Hours Of Valid Stability Observations 167789 Total Hours Of Stability Class G 13078 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class G 12755 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 164406 Total Hours Calm 1448 Meteorological facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters METEOROLOGY Wind Speed And Direction Measured at 9.72 Meter Level WBNP-101 Mean Wind Speed = 1.23 Date Printed: 20-SEP-94 NOTE: Totals And Subtotals AreObtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-52 Joint Percentage Frequencies Of Wind Speed By Stability Class, Watts Bar Nuclear Plant Jan 1, 74 - Dec 31, 93 WIND SPEED STABILITY CLASS (MPH) A B C D E F G CALM 0.001 0.000 0.000 0.108 0.748 1.262 0.881 0.6-1.4 0.008 0.006 0.015 1.450 6.208 7.598 4.525 1.5-3.4 0.350 0.519 1.027 9.428 10.478 5.688 2.280 3.5-5.4 0.925 1.072 2.097 9.828 4.925 0.609 0.068 5.5-7.4 1.102 0.944 1.494 7.014 2.415 0.119 0.004 7.5-12.4 1.563 0.982 1.460 7.463 1.658 0.035 0.001 12.5-18.4 0.210 0.123 0.184 0.751 0.280 0.001 0.000 18.5-24.4 0.008 0.007 0.009 0.042 0.028 0.000 0.000

>=24.5 0.000 0.000 0.000 0.001 0.000 0.000 0.000 TOTAL 4.166 3.654 6.286 36.085 26.739 15.311 7.758 Total Hours Of Valid Stability Observations 167789 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 164406 Total Hours Of Observations 175320 Joint Recoverability Percentage 93.8 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters Wind Speed And Direction Measured At 9.72 Meter Level Date Printed: 20-SEP-94 2.3-83 WBNP-101

2.3-84 WATTS BAR Table 2.3-53 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class A (Delta T<=-1.9 C/100 M),

Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 Wind Wind Speed (Mph)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.000 0.000 0.006 0.019 0.029 0.072 0.016 0.001 0.000 0.144 NNE 0.000 0.001 0.011 0.036 0.071 0.136 0.019 0.000 0.000 0.275 NE 0.000 0.002 0.032 0.066 0.091 0.128 0.009 0.000 0.000 0.327 ENE 0.000 0.001 0.035 0.073 0.076 0.072 0.003 0.000 0.000 0.261 E 0.000 0.001 0.022 0.036 0.016 0.007 0.000 0.000 0.000 0.082 ESE 0.000 0.001 0.014 0.021 0.003 0.003 0.000 0.000 0.000 0.042 SE 0.000 0.001 0.016 0.025 0.003 0.001 0.001 0.000 0.000 0.047 SSE 0.000 0.001 0.027 0.049 0.016 0.016 0.004 0.001 0.000 0.114 S 0.000 0.000 0.037 0.087 0.058 0.091 0.028 0.005 0.000 0.307 SSW 0.000 0.001 0.032 0.161 0.261 0.699 0.347 0.056 0.006 1.564 SW 0.000 0.000 0.014 0.080 0.150 0.334 0.141 0.019 0.000 0.736 WSW 0.000 0.001 0.004 0.009 0.016 0.046 0.056 0.024 0.008 0.165 W 0.000 0.000 0.001 0.003 0.005 0.032 0.039 0.002 0.003 0.085 WNW 0.000 0.000 0.001 0.003 0.001 0.023 0.036 0.001 0.000 0.066 NW 0.000 0.001 0.001 0.002 0.002 0.019 0.014 0.002 0.000 0.041 NNW 0.000 0.001 0.004 0.009 0.014 0.043 0.016 0.001 0.000 0.088 SUBTOTAL 0.001 0.011 0.258 0.680 0.813 1.721 0.728 0.114 0.017 4.343 Total Hours Of Valid Stability Observations 144312 Total Hours Of Stability Class A 6198 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class A 6089 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 140205 Total Hours Calm 2 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 and 45.63 Meters METEOROLOGY Wind Speed And Direction Measured At 46.36 Meter Level WBNP-101 Mean Wind Speed = 9.02 Date Printed: 29-NOV-94 NOTE: Total And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-54 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class B (-1.9< Delta T<=-1.7 C/100 M), Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 Wind Wind Speed(MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.000 0.001 0.024 0.037 0.051 0.103 0.019 0.001 0.000 0.237 NNE 0.000 0.001 0.039 0.083 0.091 0.198 0.041 0.000 0.000 0.453 NE 0.000 0.000 0.055 0.125 0.106 0.138 0.012 0.000 0.000 0.437 ENE 0.000 0.002 0.075 0.093 0.088 0.064 0.001 0.000 0.000 0.324 E 0.000 0.001 0.036 0.044 0.020 0.006 0.001 0.000 0.000 0.108 ESE 0.000 0.001 0.016 0.028 0.003 0.001 0.000 0.000 0.000 0.049 SE 0.000 0.000 0.020 0.029 0.006 0.003 0.001 0.001 0.000 0.059 SSE 0.000 0.001 0.031 0.049 0.009 0.008 0.001 0.000 0.000 0.098 S 0.000 0.000 0.034 0.078 0.049 0.044 0.010 0.004 0.001 0.220 SSW 0.000 0.001 0.050 0.160 0.178 0.293 0.111 0.029 0.004 0.826 SW 0.000 0.000 0.021 0.103 0.148 0.161 0.044 0.007 0.002 0.486 WSW 0.000 0.000 0.005 0.014 0.016 0.045 0.015 0.008 0.001 0.105 W 0.000 0.000 0.004 0.005 0.005 0.040 0.031 0.009 0.001 0.093 WNW 0.000 0.000 0.004 0.004 0.006 0.063 0.039 0.001 0.001 0.117 NW 0.000 0.000 0.002 0.009 0.006 0.056 0.024 0.001 0.001 0.098 NNW 0.000 0.000 0.005 0.016 0.024 0.068 0.039 0.004 0.001 0.155 SUBTOTAL 0.001 0.007 0.422 0.876 0.806 1.292 0.387 0.063 0.011 3.866 Total Hours Of Valid Stability Observations 144312 Total Hours Of Stability Class B 5522 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class B 5420 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 140205 Total Hours Calm 1 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters Wind Speed And Direction Measured At 46.36 Meter Level WBNP-101 Mean Wind Speed = 7.71 Date Printed: 29-NOV-94 Note: Totals And Subtotals Are Obtained From Unrounded Numbers 2.3-85

2.3-86 WATTS BAR Table 2.3-55 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class C (-1.7< Delta T<=-1.5 C/100 M), Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.000 0.001 0.030 0.087 0.091 0.178 0.039 0.001 0.000 0.427 NNE 0.000 0.002 0.068 0.138 0.178 0.314 0.070 0.000 0.000 0.770 NE 0.000 0.004 0.122 0.215 0.172 0.201 0.016 0.000 0.000 0.730 ENE 0.000 0.004 0.133 0.168 0.123 0.049 0.006 0.000 0.000 0.482 E 0.000 0.001 0.048 0.087 0.018 0.009 0.000 0.000 0.000 0.163 ESE 0.000 0.001 0.031 0.051 0.007 0.002 0.000 0.000 0.000 0.092 SE 0.000 0.001 0.044 0.044 0.006 0.001 0.003 0.001 0.000 0.101 SSE 0.000 0.001 0.049 0.078 0.027 0.014 0.006 0.001 0.000 0.176 S 0.000 0.001 0.070 0.127 0.068 0.057 0.020 0.009 0.001 0.352 SSW 0.000 0.003 0.076 0.270 0.270 0.331 0.115 0.028 0.004 1.096 SW 0.000 0.001 0.039 0.165 0.193 0.192 0.037 0.011 0.001 0.638 WSW 0.000 0.001 0.015 0.036 0.033 0.048 0.020 0.009 0.001 0.163 W 0.000 0.000 0.011 0.016 0.019 0.059 0.023 0.005 0.001 0.135 WNW 0.000 0.000 0.006 0.011 0.026 0.106 0.067 0.011 0.000 0.226 NW 0.000 0.001 0.011 0.020 0.024 0.132 0.051 0.001 0.000 0.239 NNW 0.000 0.001 0.020 0.031 0.041 0.121 0.045 0.002 0.000 0.262 SUBTOTAL 0.001 0.022 0.772 1.544 1.296 1.814 0.516 0.078 0.009 6.051 Total Hours Of Valid Stability Observations 144312 Total Hours Of Stability Class C 8714 Total Hours Of Valid Wind Direction-wind Speed-stability Class C 8484 Total Hours Of Valid Wind Direction-wind Speed-stability Observations 140205 Total Hours Calm 1 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-t Between 9.51 And 45.63 Meters METEOROLOGY Wind Speed And Direction Measured At 46.36 Meter Level WBNP-101 Mean Wind Speed = 7.24 Date Printed: 29-NOV-94 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-56 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class D (-1.5< Delta T<=-0.5 C/100 M), Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 Wind Wind Speed(MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.006 0.047 0.324 0.516 0.633 1.831 0.384 0.009 0.000 3.749 NNE 0.008 0.068 0.435 0.852 1.134 1.933 0.294 0.007 0.000 4.731 NE 0.012 0.101 0.718 1.040 0.901 0.962 0.088 0.001 0.000 3.822 ENE 0.012 0.116 0.660 0.569 0.310 0.164 0.012 0.000 0.000 1.843 E 0.008 0.102 0.402 0.215 0.104 0.043 0.004 0.000 0.000 0.878 ESE 0.004 0.058 0.213 0.107 0.021 0.013 0.002 0.000 0.000 0.419 SE 0.004 0.059 0.240 0.150 0.038 0.037 0.008 0.004 0.000 0.539 SSE 0.007 0.086 0.393 0.247 0.068 0.066 0.039 0.009 0.000 0.914 S 0.010 0.085 0.588 0.553 0.271 0.285 0.133 0.044 0.006 1.976 SSW 0.014 0.083 0.824 1.378 1.026 1.387 0.718 0.145 0.016 5.590 SW 0.009 0.063 0.558 0.880 0.622 0.745 0.238 0.038 0.009 3.162 WSW 0.006 0.061 0.361 0.331 0.210 0.302 0.118 0.020 0.006 1.416 W 0.005 0.068 0.233 0.194 0.188 0.484 0.198 0.030 0.002 1.402 WNW 0.004 0.052 0.185 0.188 0.257 0.867 0.277 0.017 0.000 1.847 NW 0.004 0.054 0.230 0.215 0.356 0.964 0.279 0.020 0.001 2.123 NNW 0.004 0.039 0.226 0.306 0.383 1.080 0.335 0.012 0.000 2.385 SUBTOTAL 0.116 1.144 6.589 7.742 6.522 11.162 3.128 0.356 0.039 36.798 Total Hours Of Valid Stability Observations 144312 Total Hours Of Stability Class D 52796 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class D 51592 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 140205 Total Hours Calm 162 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters Wind Speed And Direction Measured At 46.36 Meter Level WBNP-101 Mean Wind Speed = 6.93 Date Printed: 29-NOV-94 2.3-87 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

2.3-88 WATTS BAR Table 2.3-57 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class E (-0.5< Delta T<= 1.5 C/100 M), Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 Wind Wind Speed(Mph)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.030 0.168 0.363 0.275 0.415 0.595 0.019 0.000 0.000 1.865 NNE 0.051 0.242 0.655 0.561 0.436 0.337 0.007 0.000 0.000 2.288 NE 0.070 0.336 0.893 0.540 0.273 0.123 0.004 0.000 0.000 2.239 ENE 0.054 0.336 0.622 0.216 0.070 0.039 0.003 0.000 0.000 1.339 E 0.031 0.270 0.281 0.082 0.034 0.021 0.003 0.000 0.000 0.722 ESE 0.017 0.157 0.137 0.056 0.019 0.006 0.000 0.001 0.000 0.393 SE 0.017 0.133 0.166 0.062 0.037 0.046 0.012 0.003 0.000 0.476 SSE 0.032 0.205 0.359 0.155 0.073 0.120 0.049 0.008 0.000 1.002 S 0.058 0.275 0.749 0.509 0.311 0.340 0.126 0.032 0.006 2.406 SSW 0.080 0.303 1.108 1.282 1.081 1.430 0.575 0.099 0.003 5.961 SW 0.044 0.205 0.575 0.538 0.439 0.729 0.223 0.026 0.003 2.782 WSW 0.025 0.168 0.277 0.225 0.159 0.255 0.083 0.010 0.001 1.202 W 0.020 0.124 0.220 0.127 0.133 0.211 0.037 0.004 0.000 0.875 WNW 0.016 0.121 0.170 0.135 0.123 0.160 0.016 0.001 0.000 0.741 NW 0.018 0.121 0.203 0.138 0.205 0.205 0.019 0.001 0.000 0.910 NNW 0.018 0.118 0.196 0.149 0.183 0.223 0.023 0.000 0.000 0.910 SUBTOTAL 0.581 3.281 6.976 5.049 3.992 4.840 1.198 0.184 0.012 26.112 Total Hours Of Valid Stability Observations 144312 Total Hours Of Stability Class E 37823 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class E 36611 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 140205 Total Hours Calm 814 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters METEOROLOGY Wind Speed And Direction Measured At 46.36 Meter Level WBNP-101 Mean Wind Speed = 5.17 Date Printed: 29-NOV-94 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-58 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class F (1.5< Delta T<= 4.0 C/100 M), Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.057 0.223 0.333 0.142 0.086 0.032 0.001 0.000 0.000 0.875 NNE 0.110 0.314 0.757 0.388 0.147 0.031 0.000 0.000 0.000 1.747 NE 0.147 0.469 0.964 0.293 0.059 0.010 0.000 0.000 0.000 1.943 ENE 0.105 0.377 0.645 0.071 0.006 0.001 0.000 0.000 0.000 1.207 E 0.049 0.291 0.190 0.010 0.003 0.002 0.000 0.000 0.000 0.546 ESE 0.023 0.151 0.072 0.008 0.002 0.000 0.000 0.000 0.000 0.256 SE 0.026 0.150 0.106 0.018 0.009 0.004 0.000 0.000 0.000 0.314 SSE 0.050 0.206 0.278 0.061 0.016 0.016 0.000 0.000 0.000 0.626 S 0.094 0.297 0.617 0.254 0.086 0.046 0.001 0.001 0.000 1.397 SSW 0.111 0.270 0.814 0.689 0.450 0.334 0.029 0.000 0.000 2.698 SW 0.066 0.240 0.405 0.208 0.130 0.173 0.027 0.001 0.000 1.251 WSW 0.037 0.153 0.205 0.079 0.056 0.056 0.004 0.001 0.000 0.591 W 0.033 0.168 0.155 0.049 0.032 0.019 0.001 0.000 0.000 0.458 WNW 0.026 0.150 0.106 0.046 0.025 0.015 0.000 0.000 0.000 0.369 NW 0.028 0.132 0.136 0.060 0.038 0.018 0.001 0.000 0.000 0.412 NNW 0.033 0.155 0.165 0.066 0.053 0.020 0.001 0.000 0.000 0.493 SUBTOTAL 0.997 3.749 5.950 2.442 1.198 0.777 0.066 0.003 0.000 15.182 Total Hours Of Valid Stability Observations 144312 Total Hours Of Stability Class F 22122 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class F 21286 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 140205 Total Hours Calm 1398 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters Wind Speed And Direction Measured At 46.36 Meter Level Mean Wind Speed = 2.91 Date Printed: 29-NOV-94 WBNP-101 Note: Totals and Subtotals are Obtained from Unrounded Numbers 2.3-89

2.3-90 WATTS BAR Table 2.3-59 Joint Percentage Frequencies Of Wind Speed By Wind Direction For Stability Class G (Delta T > 4.0 C/100 M) Watts, Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 Wind Wind Speed (MPH)

Direction Calm 0.6-1.4 1.5-3.4 3.5-5.4 5.5-7.4 7.5-12.4 12.5-18.4 18.5-24.4 >=24.5 Total N 0.023 0.123 0.205 0.087 0.017 0.009 0.000 0.000 0.000 0.465 NNE 0.041 0.185 0.415 0.195 0.066 0.009 0.000 0.000 0.000 0.912 NE 0.063 0.238 0.674 0.208 0.034 0.004 0.000 0.000 0.000 1.220 ENE 0.043 0.179 0.439 0.053 0.001 0.001 0.000 0.000 0.000 0.715 E 0.014 0.109 0.087 0.004 0.000 0.001 0.000 0.000 0.000 0.215 ESE 0.006 0.051 0.038 0.006 0.000 0.000 0.000 0.000 0.000 0.101 SE 0.007 0.046 0.049 0.005 0.003 0.001 0.000 0.000 0.000 0.111 SSE 0.018 0.081 0.175 0.035 0.009 0.003 0.000 0.000 0.000 0.319 S 0.033 0.113 0.367 0.178 0.043 0.011 0.000 0.000 0.000 0.745 SSW 0.032 0.092 0.376 0.424 0.218 0.091 0.002 0.000 0.000 1.235 SW 0.018 0.081 0.175 0.108 0.046 0.034 0.001 0.000 0.000 0.463 WSW 0.012 0.065 0.113 0.044 0.023 0.009 0.000 0.000 0.000 0.265 W 0.011 0.068 0.091 0.027 0.016 0.008 0.000 0.000 0.000 0.220 WNW 0.010 0.070 0.069 0.027 0.010 0.004 0.000 0.000 0.000 0.189 NW 0.011 0.082 0.080 0.041 0.015 0.004 0.000 0.000 0.000 0.233 NNW 0.012 0.073 0.096 0.041 0.018 0.001 0.000 0.000 0.000 0.240 SUBTOTAL 0.353 1.655 3.449 1.484 0.517 0.188 0.003 0.000 0.000 7.648 Total Hours Of Valid Stability Observations 144312 Total Hours Of Stability Class G 11137 Total Hours Of Valid Wind Direction-Wind Speed-Stability Class G 10723 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 140205 Total Hours Calm 495 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On Delta-T Between 9.51 And 45.63 Meters Wind Speed And Direction Measured At 46.36 Meter Level METEOROLOGY Mean Wind Speed = 2.78 Date Printed: 29-NOV-94 WBNP-101 Note: Totals And Subtotals Are Obtained From Unrounded Numbers

METEOROLOGY WATTS BAR Table 2.3-60 Joint Percentage Frequencies Of Wind Speed By Stability Class, Watts Bar Nuclear Plant Jan 1, 77 - Dec 31, 93 Wind Speed Stability Class (MPH) A B C D E F G CALM 0.001 0.001 0.001 0.116 0.581 0.997 0.353 0.6-1.4 0.011 0.007 0.022 1.144 3.281 3.749 1.655 1.5-3.4 0.258 0.422 0.772 6.589 6.976 5.950 3.449 3.5-5.4 0.680 0.876 1.544 7.742 5.049 2.442 1.484 5.5-7.4 0.813 0.806 1.296 6.522 3.992 1.198 0.517 7.5-12.4 1.721 1.292 1.814 11.162 4.840 0.777 0.188 12.5-18.4 0.728 0.387 0.516 3.128 1.198 0.066 0.003 18.5-24.4 0.114 0.063 0.078 0.356 0.184 0.003 0.000

>=24.5 0.017 0.011 0.009 0.039 0.012 0.000 0.000 TOTAL 4.343 3.866 6.051 36.798 26.112 15.182 7.648 Total Hours Of Valid Stability Observations 144312 Total Hours Of Valid Wind Direction-Wind Speed-Stability Observations 140205 Total Hours Of Observations 149016 Joint Recoverability Percentage 94.1 Meteorological Facility: Watts Bar Nuclear Plant Stability Based On t Between 9.51 And 45.63 Meters Wind Speed And Direction Measured At 46.36 Meter Level Date Printed: 29-NOV-94 2.3-91 WBNP-101

WATTS BAR WBNP-101 Table 2.3-61 Calculated 1-hour Average Atmospheric Dispersion Factors (X/q) At Minimum Distance (1100 Meters) Between Release Zone (100 M Radius) And Exclusion Area Boundary (1200 M Radius) For Watts Bar Nuclear Plant (Sheet 1 of 1)

Based on RG 1.145 and Meteorological Data for 1974 Through 1988*

Plume Sector 0.5th Percentile 5th Percentile Direction X/Q Value (sec/m3) X/Q Value (sec/m3)

N 3.312E-4 3.396E-5 NNE 3.341E-4 4.596E-5 NE 3.954E-4 3.314E-5 ENE 5.060E-4 2.883E-5 E 5.293E-4 3.177E-5 ESE 5.321E-4 2.721E-5 SE 6.040E-4 5.996E-5 SSE 4.705E-4 2.622E-5 S 3.068E-4 2.662E-5 SSW 2.901E-4 2.806E-5 SW 3.441E-4 1.791E-5 WSW 4.394E-4 3.217E-5 W 3.704E-4 -**

WNW 1.322E-4 -**

NW 2.242E-4 -**

NNW 3.154E-4 -**

All Directions 1.217E-3 5.323E-4 Combined

Meteorological facility located 0.8 km SSW of reactor site. Temperature instruments 9.51 and 45.63 meters above ground. Wind speed and direction measured at 9.72-meter level. Joint percent valid data in data base = 93.4.

- Less than 5% of the hours had nonzero X/Q values.

2.3-92 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-61a Calculated 1-hour Average Atmospheric Dispersion Factors (X/q) At Minimum Distance (1100 Meters) Between Release Zone (100 M Radius) And Exclusion Area Boundary (1200 M Radius) For Watts Bar Nuclear Plant (Sheet 1 of 1)

Based On Rg 1.145 And Meteorological Data For 1974 Through 1993*

Plume Sector 0.5th Percentile 5th Percentile Direction X/Q Value (sec/m3) X/Q Value (sec/m3)

N 3.674E-4 3.550E-5 NNE 3.808E-4 5.036E-5 NE 4.597E-4 3.990E-5 ENE 5.305E-4 3.181E-5 E 5.297E-4 2.989E-5 ESE 5.089E-4 2.572E-5 SE 6.069E-4 4.769E-5 SSE 4.645E-4 2.375E-5 S 3.452E-4 2.598E-5 SSW 3.171E-4 2.721E-5 SW 3.703E-4 2.376E-5 WSW 4.728E-4 3.286E-5 W 3.701E-4 -**

WNW 1.452E-4 -**

NW 2.357E-4 -**

NNW 3.239E-4 -**

All Directions 9.297E-3 5.263E-5 Combined

Meteorological facility located 0.8 km SSW of reactor site. Temperature instruments 9.51 and 45.63 meters above ground. Wind speed and direction measured at 9.72-meter level. Joint percent valid data in data base = 93.7.

- Less than 5% of the hours had nonzero X/Q values.

METEOROLOGY 2.3-93

WATTS BAR WBNP-101 Table 2.3-62 Calculated 1-hour Average And Annual Average Atmospheric Dispersion Factors (X/q) At Low Population Zone Distance (4828 Meters) For Watts Bar Nuclear Plant Based on R.G. 1.145 and Meteorological Data for 1974 Through 1988*

Plume Sector 0.5th Percentile 5th Percentile Annual Average Direction x/Q Value (sec/m3) x/Q Value (sec/m3) x/Q Value (sec/m3)

N 7.665E-5 4.828E-6 7.054E-7 NNE 7.799E-5 8.040E-6 1.150E-6 NE 9.809E-5 4.720E-6 1.225E-6 ENE 1.298E-4 3.714E-6 1.282E-6 E 1.348E-4 4.333E-6 1.391E-6 ESE 1.331E-4 3.357E-6 1.533E-6 SE 1.445E-4 1.060E-5 1.467E-6 SSE 1.183E-4 3.148E-6 9.964E-7 S 7.146E-5 3.246E-6 7.454E-7 SSW 6.759E-5 3.542E-6 7.091E-7 SW 8.790E-5 1.467E-6 8.111E-7 WSW 1.206E-4 4.466E-6 9.701E-7 W 9.350E-5 -** 4.400E-7 WNW 2.284E-5 -** 2.335E-7 NW 4.944E-5 -** 2.507E-7 NNW 7.223E-5 -** 3.935E-7 All Directions 2.717E-4 1.352E-4 -

Combined

Meteorological facility located 0.8 km SSW of reactor site. Temperature instruments 9.51 and 45.63 meters above ground. Wind speed and direction measured at 9.72-meter level. Joint percent valid data in data base = 93.4.

- Less than 5% of the hours had nonzero x/Q values.

2.3-94 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-62a Calculated 1-hour Average And Annual Average Atmospheric Dispersion Factors (X/q) At Low Population Zone Distance (4828 Meters) For Watts Bar Nuclear Plant Based on R.G. 1.145 and Meteorological Data for 1974 Through 1993*

Plume Sector 0.5th Percentile 5th Percentile Annual Average Direction X/Q Value (sec/m3) X/Q Value (sec/m3) X/Q Value (sec/m3)

N 0.798E-4 5.094E-6 0.842E-6 NNE 0.845E-4 8.854E-6 1.386E-6 NE 1.135E-4 5.827E-6 1.639E-6 ENE 1.338E-4 4.514E-6 1.561E-6 E 1.365E-4 4.128E-6 1.600E-6 ESE 1.305E-4 3.181E-6 1.655E-6 SE 1.411E-4 7.997E-6 1.526E-6 SSE 1.161E-4 2.853E-6 1.035E-6 S 0.772E-4 3.211E-6 0.881E-6 SSW 0.731E-4 3.444E-6 0.814E-6 SW 0.930E-4 2.451E-6 1.001E-6 WSW 1.239E-4 4.608E-6 1.212E-6 W 0.897E-4 -** 0.469E-6 WNW 0.265E-4 -** 0.263E-6 NW 0.502E-4 -** 0.272E-6 NNW 0.691E-4 -** 0.416E-6 All Directions 2.797E-4 1.349E-4 -

Combined

Meteorological facility located 0.8 km SSW of reactor site. Temperature instruments 9.51 and 45.63 meters above ground. Wind speed and direction measured at 9.72-meter level. Joint percent valid data in data base = 93.7.

- Less than 5% of the hours had nonzero X/Q values.

METEOROLOGY 2.3-95

WATTS BAR WBNP-101 Table 2.3-63 Values Of 5th Percentile Overall Site 8-hour, 16-hour, 3-day, And 26-day Atmospheric Dispersion Factors (X/q) At Low Population Zone Distance (4828 Meters) For Watts Bar Nuclear Plant Based on R.G. 1.145 Method of Logarithmic Interpolation Between Overall 5th Percentile 1-hour X/Q Assumed to Apply for 2-hour Period and Maximum Sector Annual Average X/Q (underscored in Table 2.3-62)*

5th Percentile Averaging Period X/Q Value (sec/m3) 8-hour 6.447E-5 16-hour 4.452E-5 3-day 1.993E-5 26-day 6.288E-6

1-hour and annual average X/Qs calculated from meteorological data for 1974 through 1988.

Meteorological facility located 0.8 km SSW of reactor site. Temperature instruments 9.51 and 45.63 meters above ground. Wind speed and direction measured at 9.72-meter level. Joint percent valid data in data base = 93.4.

2.3-96 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-63a VALUES OF 5TH PERCENTILE OVERALL SITE 8-HOUR, 16-HOUR, 3-DAY, AND 26-DAY ATMOSPHERIC DISPERSION FACTORS (X/Q) AT LOW POPULATION ZONE DISTANCE (4828 METERS) FOR WATTS BAR NUCLEAR PLANT Based on RG 1.145 Method of Logarithmic Interpolation Between Overall 5th Percentile 1-hour X/Q Assumed to Apply for 2-hour Period and Maximum Sector Annual Average X/Q (from Table 2.3-62a)*

5th Percentile Averaging Period X/Q Value (sec/m3) 8-hour 6.516E-5 16-hour 4.529E-5 3-day 2.057E-5 26-day 6.621E-6

1-hour and annual average X/Qs calculated from meteorological data for 1974 through 1993.

Meteorological facility located 0.8 km SSW of reactor site. Temperature instruments 9.51 and 45.63 meters above ground. Wind speed and direction measured at 9.72-meter level. Joint percent valid data in data base = 93.7.

METEOROLOGY 2.3-97

WATTS BAR WBNP-101 Table 2.3-64 0.5th Percentile Sector Values Of 8-hour, 16-hour, 3-day, And 26-day Atmospheric Dispersion Factors (X/q) At Low Population Zone Outer Boundary Distance (4828 Meters) For Watts Bar Nuclear Plant Based on R.G. 1.145 Method of Logarithmic Interpolation Between 0.5th Percentile 1-hour X/Q for Each Sector and Annual Average X/Q for Same Sector.*

Sector-Specific X/Q Values (sec/m3)

Plume Sector 8-hour 16-hour 3-day 26-day N 3.531E-5 2.396E-5 1.034E-5 3.090E-6 NNE 3.884E-5 2.741E-5 1.286E-5 4.342E-6 NE 4.752E-5 3.308E-5 1.507E-5 4.874E-6 ENE 6.049E-5 4.130E-5 1.804E-5 5.492E-6 E 6.328E-5 4.336E-5 1.909E-5 5.877E-6 ESE 6.363E-5 4.399E-5 1.975E-5 6.257E-6 SE 6.765E-5 4.629E-5 2.032E-5 6.230E-6 SSE 5.370E-5 3.618E-5 1.536E-5 4.488E-6 S 3.361E-5 2.305E-5 1.017E-5 3.139E-6 SSW 3.182E-5 2.183E-5 9.639E-6 2.980E-6 SW 4.051E-5 2.750E-5 1.187E-5 3.550E-6 WSW 5.433E-5 3.647E-5 1.535E-5 4.433E-6 W 3.855E-5 2.475E-5 9.465E-6 2.381E-6 WNW 1.071E-5 7.329E-6 3.221E-6 9.895E-7 NW 2.064E-5 1.333E-5 5.167E-6 1.325E-6 NNW 3.051E-5 1.983E-S 7.784E-6 2.033E-6

1-hour and annual average X/Qs calculated from meteorological data for 1974 through 1988.

Meteorological facility located 0.8 km SSW of reactor site. Temperature instruments 9.51 and 45.63 meters above ground. Wind speed and direction measured at 9.72-meter level. Joint percent valid data in data base = 93.4.

2.3-98 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-65 0.5th Percentile Sector Values Of 8-hour, 16-hour, 3-day, And 26-day Atmospheric Dispersion Factors (X/q) At Low Population Zone Outer Boundary Distance (4828 Meters) For Watts Bar Nuclear Plant Based on RG 1.145 Method of Logarithmic Interpolation Between 0.5th Percentile 1-hour X/Q for Each Sector and Annual Average X/Q for Same Sector.*

Sector-Specific X/Q Values (sec/m3)

Plume Sector 8-hour 16-hour 3-day 26-day N 3.760E-5 2.581E-5 1.141E-5 3.534E-6 NNE 4.281E-5 3.048E-5 1.458E-5 5.060E-6 NE 5.631E-5 3.967E-5 1.855E-5 6.228E-6 ENE 6.412E-5 4.438E-5 1.997E-5 6.347E-6 E 6.545E-5 4.532E-5 2.041E-5 6.494E-6 ESE 6.340E-5 4.418E-5 2.018E-5 6.553E-6 SE 6.677E-5 4.592E-5 2.039E-5 6.353E-6 SSE 5.319E-5 3.601E-5 1.544E-5 4.579E-6 S 3.683E-5 2.545E-5 1.141E-5 3.606E-6 SSW 3.475E-5 2.396E-5 1.070E-5 3.359E-6 SW 4.397E-5 3.023E-5 1.341E-5 4.174E-6 WSW 5.765E-5 3.933E-5 1.715E-5 5.208E-6 W 3.763E-5 2.438E-5 0.950E-5 2.458E-6 WNW 1.234E-5 0.843E-5 0.369E-5 1.124E-6 NW 2.116E-5 1.375E-5 0.539E-5 1.406E-6 NNW 2.969E-5 1.946E-5 0.777E-5 2.084E-6

1-hour and annual average X/Qs calculated from meteorological data for 1974 through 1993.

Meteorological facility located 0.8 km SSW of reactor site. Temperature instruments 9.51 and 45.63 meters above ground. Wind speed and direction measured at 9.72-meter level. Joint percent valid data in data base = 93.7.

METEOROLOGY 2.3-99

WATTS BAR WBNP-101 Table 2.3-66 Atmospheric Dispersion Factors (X/q), Sec/m3, For Design Basis Accident Analyses Based On Onsite Meteorological Data For Watts Bar Nuclear Planta (Sheet 1 of 1)

A. Regulatory Guide 1.4 Results in original FSAR (5th percentile values) for July 1973 Through June 1975 Data.b Minimum Distance to Period Exclusion Boundary Low Population Zone (hours) (1100 m)c (4828 m) 0-2 0.692E-3d 0.160E-3d 2-8 - 0.844E-4d 8-24 - 0.854E-5 24-96 - 0.455E-5 96-720 - 0.198E-5 B. Regulatory Guide 1.145 Results (maximum sector 0.5th percentile 1-hour value for 0-2 hours at exclusion area boundary and at low population zone; and 8-hour, 16-hour, 3-day and 26-day values for 2-8, 8-24, 24-96, and 96-720 hours from logarithmic interpolation between 0.5th percentile maximum sector 1-hour value at 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and corresponding sector annual average value at 8760 hours0.101 days 2.433 hours 0.0145 weeks 0.00333 months at low population zone) for 1974 through 1988 Datae.

Period (1100 m)c (4828 m) 0-2 0.604E-3 0.145E-3 2-8 - 0.677E-4 8-24 - 0.463E-4 24-96 - 0.203E-4 96-720 - 0.623E-5 a

Hourly 10-m wind and 10- and 46-m temperature data. Meteorological facility located 0.8 km SSW of reactor site.

b Calms assigned a wind speed of 0.3 mph.

c Travel distance from 100-m radius release zone to 1200-m exclusion area boundary distance.

d Actual 2-hour and 6-hour X/Q averaging periods were used.

e Calms assigned a wind speed of 0.6 mph.

2.3-100 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-66a Atmospheric Dispersion Factors (X/q), Sec/m3, For Design Basis Accident Analyses Based On Onsite Meteorological Data For Watts Bar Nuclear Plant1 A. Regulatory Guide 1.4 Results in original FSAR (5th percentile values) for July 1973 Through June 1975 Data.2 Minimum Distance to Period Exclusion Boundary Low Population Zone (hours) (1100 m)3 (4828 m) 0-2 0.692E-34 0.160E-34 2-8 - 0.844E-44 8-24 - 0.854E-5 24-96 - 0.455E-5 96-720 - 0.198E-5 B. Regulatory Guide 1.145 Results (maximum sector 0.5th percentile 1-hour value for 0-2 hours at exclusion area boundary and at low population zone; and 8-hour, 16-hour, 3-day and 26-day values for 2-8, 8-24, 24-96, and 96-720 hours from logarithmic interpolation between 0.5th percentile maximum sector 1-hour value at 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and corresponding sector annual average value at 8760 hours0.101 days 2.433 hours 0.0145 weeks 0.00333 months at low population zone) for 1974 through 1993 Data5.

Minimum Distance to Period Exclusion Boundary Low Population Zone (hours) (1100 m)3 (4828 m) 0-2 0.607E-3 0.141E-3 2-8 - 0.668E-4 8-24 - 0.459E-4 24-96 - 0.204E-4 96-720 - 0.635E-5

1. Hourly 10-m wind and 10 and 46-meter temperature data. Meteorological facility located 0.8 km SSW of reactor site.

2. Calms assigned a wind speed of 0.3 mph.

3. Travel distance from 100-m radius release zone to 1200-m exclusion area boundary distance.

4. Actual 2-hour and 6-hour X/Q averaging periods were used.

5. Calms assigned a wind speed of 0.6 mph.

METEOROLOGY 2.3-101

WATTS BAR WBNP-101 Table 2.3-67 Dispersion Meteorology - Onsite 10-meter Wind Data - 5th Percentile Values Of Inverse Wind Speed (1/u) Distributions For Post-loca Control Bay Dose Calculations For Watts Bar Nuclear Plant A. July 1973 through June 1975 Wind Speed and Direction Data Plume Sectors Averaging Periods (degrees) 1-hour 8-hour 16-hour 3-day 26-day 89.75-157.25 1.59 0.834 0.670 0.447 0.348 132.25-199.75 1.61 0.864 0.688 0.496 0.361 154.75-222.25 1.44 0.743 0.598 0.441 0.300 192.25-259.75 1.33 0.719 0.601 0.437 0.302 B. January 1974 through December 1988 Wind Speed and Direction Data Plume Sectors Averaging Periods (degrees) 1-hour 8-hour 16-hour 3-day 26-day 89.75-157.25 1.82 1.04 0.852 0.593 0.463 132.25-199.75 1.27 0.760 0.626 0.440 0.316 154.75-222.25 0.866 0.574 0.497 0.360 0.264 192.25-259.75 1.04 0.653 0.576 0.416 0.266 NOTE: The calculations for the 2-year data base were slightly conservative in comparison to those for the 15-year data base. The 2-year values were computed in 1976 with the speed assigned to calm hours assumed to be 0.3 mph. The 15-year values were computed in 1989 with the speed assigned to calms assumed to be 0.6 mph, which is the starting threshold for the anemometer.

Meteorological facility located 0.8 km SSW of reactor site.

2.3-102 METEOROLOGY

WATTS BAR WBNP-101 Table 2.3-67a Dispersion Meteorology - Onsite 10-meter Wind Data - 5th Percentile Values Of Inverse Wind Speed (1/u) Distributions For Post-loca Control Bay Dose Calculations For Watts Bar Nuclear Plant A. July 1973 through June 1975 Wind Speed and Direction Data Plume Sectors Averaging Periods (degrees) 1-hour 8-hour 16-hour 3-day 26-day 89.75-157.25 1.59 0.834 0.670 0.447 0.348 132.25-199.75 1.61 0.864 0.688 0.496 0.361 154.75-222.25 1.44 0.743 0.598 0.441 0.300 192.25-259.75 1.33 0.719 0.601 0.437 0.302 B. January 1974 through December 1993 Wind Speed and Direction Data Plume Sectors Averaging Periods (degrees) 1-hour 8-hour 16-hour 3-day 26-day 89.75-157.25 1.97 1.04 0.862 0.607 0.456 132.25-199.75 1.29 0.784 0.626 0.434 0.312 154.75-222.25 0.891 0.606 0.516 0.368 0.255 192.25-259.75 1.10 0.713 0.610 0.435 0.300 NOTE: The 2-year values were computed in 1976 with the speed assigned to calm hours assumed to be 0.3 mph. The 20-year values were computed in 1994 with the speed assigned to calms assumed to be 0.6 mph, which is the starting threshold for the anemometer.

Meteorological facility located 0.8 km SSW of reactor site.

METEOROLOGY 2.3-103

WATTS BAR WBNP-101 THIS PAGE INTENTIONALLY LEFT BLANK 2.3-104 METEOROLOGY

ML103140664

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