ML20002C016
| ML20002C016 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 12/08/1980 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| Shared Package | |
| ML20002C017 | List: |
| References | |
| TASK-02-02.A, TASK-2-2.A, TASK-RR LSO5-80-12-009, LSO5-80-12-9, NUDOCS 8101070577 | |
| Download: ML20002C016 (7) | |
Text
[DR RIGgo UNITED STATES E } ) #,, 3 ',j NUCLEAR REGULATORY COMMISSION
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. C WASHINGTON, D. C. 20555 M'%/i DEC 0 81980 Docket No. 50-213 5
LS05-80-12-009
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Mr. W. G. Counsil, Vice President Nuclear Engineering and Operations i
a Connecticut Yankee Atomic Power Comany
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N Post Office Box 270 4
g Hartford, Connecticut 06101 g
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Dear Mr. Counsil:
SUBJECT:
HADDAM NECK - SEP TOPIC II-2.A, SEVERE WEATHER PHENOMENA The SEP review of Topic II-2.A, " Severe Weather Phenomena" has been cogleted. is the staff's safety evaluation (SE) for the Haddam Neck site.
The review was done in conformance with Standard Review Plan 2.3.1 and covers extreme temeratures, lightning strikes, snow and ice loads and wind and tornado loadings. The wind and tornada loadings analysis was performed by the Texas Tech. University, Institute for Disaster Research. Enclosure 2 is the Texas Tech. report. Please inform us if your as-built facility differs from the licensing basis assumed in our assessment within 30 days of receipt of this letter.
You will note that the SE identifies a design basis tornado with a probability of 10 -7 per year and is consistent with a Regulatory Guide 1.76 design basis tornado. The staff intends to evaluate the structural characteristics of specific structures, systems and cogonents igortant to safety to determine their ability to withstand the severe weather loadings. The plant design parameters will then be cowared to the probability of occurrence of the wind as a part of our structural evaluation. This cogarison will be used to evaluate the necessity of design changes.
Sincerely, l
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Dennis M. Crutchfield, ChiAf
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Operating Reactors Branch #5 Division of Licensing
Enclosure:
As stated cc w/ enclosure:
See next page l
82o107o 57
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Mr. W. G. Counsil HADDAM NECK PLANT DOCKET NO. 50-213 cc Day, Berry & Howard U. S. Environmental Protection Counselors at Law Agency One Constitution Plaza Region I Office Hartford, Connecticut 06103 ATTN: EIS C0ORDINATOR JFK Federal Building Superintendent Boston, Massachusetts 02203 Haddam Neck Plant RFD #1 Resident Inspector Post Office Box 127E Haddam Neck Nuclear Power Station East Haapton, Connecticut 06424 c/o U. S. NRC East Haddam Posh 0ffice s
Mr. Jaaes R. Himmelwright East Haddam, Connecticut 06423 Northeast Utilities Service Company P. O. Box 270 Hartford, Connecticut 06101 Russell Library 119 Broad Street Middletown, Connecticut 06457 Board of Selectmen Town Hall Haddam, Coiinecticut 06103 Connecticut Energy Agency ATTN: Assistant Director Research and Policy Development Department of Planning and Energy Policy 20 Grand Street Hartford, Connecticut 06106 f
Director, Technical Assessaent l
Division Office of Radiation Prograas (AW-459)
U. S. Environmental Protection l
Agency Crystal Mall #2 Arlington, Virginia 20460 1
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ENCLOSURE 1 Systematic Evaluation Program Meteorology Haddam Neck Nuclear Power Plant Topic II-2.A Severe Weather Phenomena Extreme meteorological conditions and severe weather phenomena in the Haddam Neck site region were examined to determine if safety-related structures, systems, and components are designed to function under all severe weather conditions.
Discussed below are the severe weather phenomena which could adversely affect the Haddam Neck site and which should be examined relative to the current design.
Normal daily temperatures range from a minimum of 18 degrees Fahrenheit in January to a maximum of 80 degrees Fahrenheit in July.
Measured extreme temperatures for the site region are 101 degrees Fahrenheit which occurred in August 1955 and -24 degrees Fahrenheit which occurred in February 1943.
The extreme maximum ar.d minimum temperatures appro-priate at the Haddam Neck site for general plant design (i.e., HVAC systems) are 90 degrees Fahrenheit (equalled or exceeded 1% of the time) l and -3 degrees Fahrenheit (equalled or exceeded 99% of the time).
l Thunderstorms occur an average of 25 days per year in the site region.
Based on the annual number of thunderstorm days, the calculated annual flash density of ground lightning strikes is three flashes per square
kilometer. A structure with the approximate dimensions of the Haddam f:eck reactor building can be expected to be subjected, on the average, to one strike every 10 years.
The design wind speed (defined as the " fastest-mile" wind speed at a height of 30 feet above ground level with a return period of 100 years) acceptable for the site region is 90 miles per hour. On the average, hail storms occur about two days annually, and freezing rain occurs approximately 10 days per year. The maximum radial thickness of ice expected in the site region is about 0.75 inch.
Mean annual snowfall in the site region is approximately 48 inches. The normal winter precipitation snow load o a flat surface is about 35 pounds per square foot. The maximum monthly sr.awfall occurred in December 1945 and totaled 45.3 inches. The maximum snowfall from a single storm totaled 19.2 inches in February 1949. The maximum measured snow depth on the ground for the site region is 32.8 inches. Based on the 100-year recurrence accumulated ground snowpack and probable maximum winter precipitation for the site region, the extreme winter precipitation snow load on a flat surface is about 125 pounds per square foot.
Tornadoes have been reported 117 times during the period 1950-1977 within an approximate 60-mile radius from the Haddam Neck site, excluding the water area over the Atlantic Ocean. On the average, four tornadoes can be expected to occur in the vicinity of the Haddam Neck l
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. site every year. Based on the path length and width of tornadoes occurring in the site region, the recurrence interval for a tornado at the site is calculated to be about 4000 years.
i The assumptions used in Regulatory Guide 1.76 provide an adequate design basis tornado for the site region.
These characteristrics include a maxiasm windspeed of 360 miles per hour (a maxinum rotational windspeed of 290 miles l
per hour plus a maximum translational windspeed of 70 miles per hour), a maximum pressure drop of three pounds per square inch, and rate of pressure drop of two pounds per square inch per second.
Based on actual t[rnado occurrences in the site region area (77 tornadoes with available data) and using the procedures discussed in WASH-1300, a " site-specific" design basis tornado (with a probability of occurrence of 10-7 per year) can be calculated. For the Haddam Neck site, the characteristics of tornadoes occurrring within a 60-mile radius are a maximum wir speed of 315 miles per hour (a maximum rotational windspeed of 255 miles per hour plus a maximum translational windspeed of 60 miles per hour), a maximum pressure drop of two pounds per square inch, and a rate of pressure drop of 1.5 pounds per square inch per second.
l
t References U.S. Department of Conaerce, NOAA, " Climates of the States," Vol.1 1974.
U.S. Department of Commerce, " Climatic Atlas of the United States."
June 1968.
U.S. Department of Connerce, NOAA, " Climates of the United States,"
1973.
U.S. Department of Connerce, NOAA, " Local Climatological Data "
Hartford and Bridgeport, Connect,ent and Providence, Rhode Island.
H. C. S. Thom, "New Distributions of Extreme Winds in -the United States,"
Journal of the Structural Division, ASCE, Vol. 94, No. ST7, July 1968.
"American National Standard Building Code Requirements for Minimum Design Loads in Buildings and Other Structures," ANSI, A58.1-1972.
" Seasonal Variation of the Irobable Maximum Precipitation East of the 105th Meridian for Areas from 10 to 1,000 Square Miles and Durations of 6,12, 24, and 48 Hours," Hydrometeorological Report No. 33, Washington, D. C., April 1956.
James A. Ruffner and Frank E. Baier, "The Weather Almanac," Gale Research Corpany,1974.
David M. Ludlum, " Weather Record Book," Weatherwise, Inc.,1973.
J. L. Marshall, " Lightning Protection," John Wiley and Sons, New York, 1973.
"ASHRAE Handbook of Fundamentals," American Society of Heating, Refrigeration and Air Conditioning Engineers, Inc., New York 1976.
Paul Tattleman and Irving I. Gringorten, " Estimated Glaze Ice and Wind Loads at the Earth's Surface for the Contiguous United States,"
Air Force Cambridge Research Laboratories, October 1973.
U.S. Housing and Home Finance Agency, " Snow Load Studies," Housing Research Paper No.19, May 1952.
U.S. Naval Weather Service, "World-Wide Airfiald Summaries," Vol. VIII, United States of America, Part 4,1969.
Memo from Harold R. Denton (Assistant Director for Site Safety, Division of Technical Review, NRR) to R. R. Maccary (Assistant Director for
5-Engineering, Division of Technical Review, NRR) dated March 24, 1975,
Subject:
Site Analysis Branch Position - Winter Precipitation Loads.
Memo from Jerry Harbour (Chief Site Safety Research Branch, Division of Reactor Safety Research, RES) to L. G. Hulman (Chief, Hydrology-Meteorology Branch, Division of Site Safety and Environmental Analysis, NRR) dated August 14, 1978,
Subject:
Tornado Frequency Data for SEP Revi ew.
Regulatory Guide 1.76, " Design Basis Tornado for Nuclear Power Plants,"
U.S. Nuclear Regulatory Commission, Washington, D.C.
WASH-1300, " Technical Basis for Interim Regional Tornado Criteria "
U.S. Atomic Energy Commission, May 1974.
H. C. S. Thom, " Tornado Probabilities," Montnly Weather Review, October-December 1963, pp. 730-736.
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