Summary Report for Conduct of Kozloduy NPP Stress Tests

“Kozloduy NPP” PLC
SUMMARY REPORT
for Conduct of Kozloduy NPP
Stress Tests
4.1.10 Evaluation of frequency of occurrence of extreme weather conditions
postulated in the design basis
Table 4.1-1: Frequency of occurrence of extreme meteorological conditions.
Extreme
Parameter value
Occurrence frequency
meteorological
conditions
Extreme winds Wind with speed 45 m/s
1×10 -4 per 1 year
27 m/s 0,1 per 1 year
20 m/s Once per year
Sand spout Wind with maximum velocity 332 6,3×10 -7 per 1 year
km/h, wind speed - 263 km/h, motion
speed - 69 km/h, radius - 45,7 m, for
area 12 500 km 2
with speed over 332 km/h
1,26×10 -8 per 1 year
Wind with max. speed 332 km/h, wind
speed - 263 km/h, motion speed - 69
km/h, radius - 45,7 m for area of
100 000 km 2 5,05х10 -6 per 1 year
Snowfalls
High temperatures
With speed over 332 km/h
1х10 -7 per 1 year
11-20 cm 24-30%
70-80 cm 3%
+43.3°С
Absolute maximum air
temperature
Low temperatures
-26,6°С
Absolute minimum air
temperature
Extreme
precipitations
518-558 mm Annual precipitation, one of
the lowest in the country
Occurrence of ice on Danube River – 62% from 100 years
ice in Oryahovo
Freezing of Danube River – ice in No data for freezing since
Oryahovo
1963
Lightning Statistics data for 2005 and 2006:
3000-4000 Lightning for June, July
and August, in noon and afternoon
hours.
Low standing on
Danube River
Probability of water level elevation
20.50m
99%
4.2 ACTUAL STANDARD REQUIREMENTS FOR LOADS FROM
EXTREME EXTERNAL EVENTS
The requirements for loads from external events are provided below as follows [141]:
Wind load:
127/202