Text

Probability Estimate of Temp Extremes for Seabrook,Nh
	ML20073M475
Person / Time
Site:	Seabrook
Issue date:	01/31/1983
From:	; UNITED ENGINEERS & CONSTRUCTORS, INC.
To:	;
Shared Package
ML20073M472	List: ML20073M467; ML20073M475;
References
	NUDOCS 8304220004
	Download: ML20073M475 (34)
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SEABROOK STATION UNITS 1 & 2

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[j PROBABILITY ESTIMATE OF TEMPERATURE EXTREMES

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PREPARED BY: United Engineers & Constructors, Inc.

DATE: January 1983 J

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8304220004 830420 PDR ADOCK 05000443

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- TABLE OF CONTENTS I Section Pase No.

1.0 INTRODUCTION

1-1 1.1 Purpose of Study 1-1 1.2 Study Summary 1-2 -

1.2.1 Representativeness Analysis 1-2 -

1.2.2 Return Period Extreme Temperatures 1-3

1 2.0 STUDY METHODOLOGY 2-1 L 2.1 Selection of Variables and Data Bases 2-1

"' 2.2 Data Bases 2-3

,I 2.2.1 Available Raw Data 2-3 2.2.2 Previously Analyzed Data 2-3 --

2-4

[l KJ 2.2.3 Representativeness Analysis 2.3 Estimation of Return Period Statistics 2-4

2.3.1 Assumption of Data Distribution Characteristics 2-4 2.3.2 Computational Methodology 2-5 2.3.2.1 Hourly Temperatures ,

2-5 2.3.2.2 Averaging Pericd Temperatures 2-6 j.

2.4 Derivation of Temperature Progression Data '2 7 -

f _, 3.0 STUDY RESULTS 3-1 3.1 Representativeness Analysis 3-1 1

! - 3.2 Fifty and 100-Year Return Period Temperatures 3-2

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3.3 Temperature Progression 3-4

4.0 CONCLUSION

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5-1

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5.0 REFERENCES

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1.0 INTRODUCTION

,J 1.1 Purpose of Study r*-

This extreme temperature analysis is designed to establish the outdoor dry bulb temperature which may be expected to recur once in every 50 or 100 P (- years for confirmation of the adequacy of safety-related equipment design.

Since the response of many safety-related f acility components to extreme conditions is characterized by a certain degree of thermal inertia, l -,t PiI this study also develops extreme temperatures (with return periods of r' 50 and 100 years) for varying temporal averaging periods.

i Additional information required to assess the degree to which thermal L inertia is important in offsetting extreme temperature conditions is also

" required. This includes the determination of the actual hourly temperature 1I .

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progression data for the warmest and coldest contiguous 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months associated i

with the observed record maximum and record minimum hourly temperature, as wellas a hypothetical hourly temperature progression for the warmest conti-1 t guous 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months associated with the 100 year return period maximum hourly ~

temperature This analysis is designed to be as site-specific as possible consider-ing the fact that only a relatively short (five years) record of hourly temperatures is available from the onsite meteorological station. Much longer periods of record are available from military and climatological stations in the general site region. Since the majority of this analysis requires hourly temperature data, the only nearby station recording hourly tem-j perature data, Psase Air Force Base (AFB), is selected. Temperature data from other area stations are then used to demonstrate that temperatures recorded J at Pease AhB are reasonably representative of the general site region.

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1.2 Study Summarv 1.2.1 Representativeness Analysis Temperature data from Pease AFB were selected for the analysis since it is the closect station to the site collecting temperature data on an hourly basis as required for this analysis. To evaluate the regional representative-

-. ness of Pease AFB, temperature data were obtained in various forms for extended

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periods of record for numerous meteorological and climatological stations in the New England region near the site. The.se data included temperatures

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from all stations used in the NUREG/CR-1390 analysis (l) as well as additional data from Rockport, Massachusetts, Sanford, Maine, and Greenland, New Hampshire.

l Analysis and comparison of data from these stations as well as considera-tion of other factors such as proximity to the coastline, station elevation, f and period of recordhave led to the following conclusions:

(1) The temperature conditions at Pease AFB are very similiar

! to those experienced at the Greenland, N.H. station due to the relatively small distance between these stations. The Greenland station, however, recorded an extremely limited amount of temperature data.

(2) Sanford, Maine and Rockport, Massachusetts experience temperature conditions more and,less extreme, respectively, than Pease AFB. These stations demonstrate the range of possible conditions in the general site region.

i (3) Pease AFB exhibits more moderate temperature extremes.than indicated for the region by the NUREG/CR-1390 analysis. The data base used to develop the isotherm maps in NUREG/CR-1390 7

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does not contain any of the stations referenced above.

The isotherms in the site region as presented in CR-1390 are heavily influenced by data from inland stations.

(4) Comparison of Seabrook and Pease AFB frequency distribu-tions for hourly observations as well as for daily maximum

,[ and minimum temperatures shows that the Pease AFB data

-- represent the Seabrook site fairly well. This comparison

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^- was conducted based on a concurrent five-year period of

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record at both stations.

2

-- The main conclusion of the representativness study is that Pease AFB temperature data are reasonably representative of temperatures recorded in the general site region. The Pease AFB measurement location and topography does differ from the site in two ways - it is farther from the ocean, and

- there is a significant body of water (Great Bay) to the south and west of the Air Force Base. These differences do not,however, produce temperature

.J conditions unrepresentative of the general site region or of the site itself.

L 1.2.2 Return Period Extreme Temperatures Table 1-1 summarizes the calculated 50- and 100-year return period extreme temperatures for Pease AFB. The 50- and 100-year extreme value

. dry bulb temperatures calculaced for Pease AFB (only 10 miles north of the di Seabrook site) are recommen".ed for use at the Seabrook site. The results for Pease AFB are based on the currently available 25 years of data.

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1-3

1 .

l Table 1-2 presents a hypothetical expected hourly temperature progression for the warmest contiguous 24-hour period in association with the 100-year return period maximum hourly temperature for Pease AFB. Table 1-3 presents the observed hourly temperature progression for the warmest 24-hour period containing the maximum observed hourly temperature for Pease AFB. Table 1-4 summarizes the frequency of hourly temperatures recorded at Pease Air Force Base. As shown in this table, the hourly temperature at Pease AFB equals or exceeds 88 F and 91 0 F for .463 percent and .104 percent of the valid hourly

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observations, respectively, and is less than or equal to 00F and -50F for

.356 percent and .111 percent of the valid hourly observations, respectively.

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TABLE 1-1 SEABROOK EXTRDE TEMPERATURE ANALYSIS MAXIMUM AND MINIMUM TEMPERATURES FOR 50- AND 100-YEAR RETURN PERIOD l-RECOMMENDED FOR USE AT SEABROOK SITE t

Temperatures (OF)

Averaging Period Return Period (years) Maximum Minimum Hourly 50 101 -19 100 102 -21 2-Hour 50 100 -19 n

j 100 102 -21 4-Hour 50 100 -18 100 101 -21 8-Hour 50 98 -18 100 99 -20 12-Hour . 50 95 -17 l

100 96 -19 24-Hour 50 86 -13 100 89 -16,

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T3BLE l-2 s SEABROOK EXTREME TEMPERATURE ANALYSIS I

O HYPOTHETICAL HOTTEST CONTIGUOUS 24-HOUR PERIOD

/ ["* IN ASSOCIATION WITH THE -

100-YEAR RETURN PERIOD MAXIMUM

,. HOURLY TEMPERATURE

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HOUR TEMPERATURE (OF) n

.[ 1 76 2 79 7 3 84 14 4 87 L' 5 92 6 94

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7 99 Ib 8 9

101 102 1 , 10 %, 102

. 11 102 12 100

, 13 99

$ fj 14 94 d 15 89

-86 16

- ., 17 '84

! 18 82 19 80 20 79

!'; 21 82

) 22 79 23 77 -

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Based on Annual Maximum Hourly Temperatures for Pease AFB (Portsmouth, N.H.)

for period 1957-1981.

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' i- SEABROOK EXTREME TEMPERATURE ANALYSIS HOTTEST CONTIGUOUS 24 HOURS IN ASSOCIATION WITH

? THE HOTTEST ONE-HOUR TEMPERATURE

,3 OBSERVED DURING 1957 THROUGH 1981 AT PEASE AFB l' YEAR DATE HOUR TEMPERATURE ( F)

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1964 June 30 15 89 16 89 C'2r 17 18 89

,85 C;

a 19 81 20 80

-- 21 77 l 22 76

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23 76 July 1 00 74

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5 73

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- 7 80 8 88

" 9 92 10 93

! 11 96

[L' 12 98 13 101

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,(;j SEABROOK EXTREME TEMPERATURE ANALYSIS

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SUMMARY

OF s FREQUENCY DISTRIBUTION OF HOURLY TEMPERATURES

/[I,3 FOR PEASE AFB AND SEABBOOK SITE O

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TEMPERATURE FREQUENCY (PERCENT)

RANGE (OF) ~ PEASE AFB SEABROOK SITE c,

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i. E 88 .463 .250 _ ,

g; 1 91 .104 .067

'[4 50 .356 .394 9 $ -5 .111 .126

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DATA BASE: Seabrook Site: November 1, 1972 - November 30, 1974 (inclusive and April 1, 1979 - June 30, 1982 (inclusive); 46,003 valid hourly observations ti] . Pease AFB: April 1,1956 - December 31, 1981 (inclusive);

~~225,093 valid hourly observations.~~

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~~, 2.0 STUDY METHODOLOGY q 2.1 Selection of Variables and Data Bases -~~

~~1 5 -} This study is concerned with severe sunumer and winter ambient tempera-ture conditions and is limited to this particular meteorological parameter.~~

Although wind and moisture conditions occurring simultaneously with severe R tagerature conditions may exacerbate or mitigate the effect of the severe lj temperatures upon certain structures systems or components, these additional

~~' -1 L affects are not addressed in the present study.~~

M y In the case of certain safety-related structures, systems, or components, use of the extreme maximum or minimum dry bulb temperature based upon near-instan-iI a tenneous or.even hourly average temperature is inappropriate. For these systems, ,

extreme tageratures expected over averaging periods of up to twenty four hours way more realistically reflect the sensitivity of such systems to severe dry bulb conditions. In many previous studies, including those referenced in NUREG/CR-1390 , the statistical analysis of expected extreme dry bulb condi-

~~{T fj tions has been based upon either airport temperature observations or obser-c vations of maximum and minimum temperatures taken by cooperative climatological~~

~~observers without consideration of the time period over which these observa-d, tions are valid. Generally, these observations are implicitly assumed to k .e loosely represent " hourly" tageratures.~~
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Observations of teg eratures by the Federal Aviation Administration, National Weather Service, or military personnel are generally made a few b]
minutes prior to the hour and represent, essentially, an instantaneous value.
Observations by cooperative observers are taken from maximum / minimum thermo-f meters and represent an averaging period of only a few minutes, at most, t,_?
U determined by the response characteristics of the shelter and thermometer.
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.s Because of the need for an extensive historical data base to provide :=
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a reasonable degree of confidence in estinating the probable magnitude j '
! of rarely occurring temperatures, onsite meteorological data (more accurately
- ;3 representing true one-hour averages) cannot be used. Airport or climatolo-I gical observer data (representing instantaneous or near-instantaneous readings) are the only recourse. The present study, therefore uses these data but
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interprets the results considering the limitations inherent in the data.
U l' For the meteorological variable of dry bulb temperature, then, this
[ study provides the following analyses:
Representativeness analysis of Pease AFB maximum and e
minimum temperatures based on data from other regional f
stations.
4 e Computation of the 50- and 100-year return period maximum -
) and minimum dry bulb temperatures based on Pease airport data to represent conditions expected to persist for i- averaging time periods of 1, 2, 4, 8, 12, and 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .
. Determination of the five warmest and five coldest 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months periods observed over the 25 year Pease AFB data base and presentation of the hourly data comprising these periods.
s o Presentation of the hourly data comprising the warmest con-
~~1. tiguous 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period containing the highest observed hourly i~~
temperature.
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s 5;P 2.2 Data Bases r .>
2.,2.1 Available Raw Data d_
L, The regional dry bulb temperature data bases listed in Table 2-1 were P obtained from the National Climatic Center (NCC). These stations listed are t*
geographically distributed about the Seabrook site as shown in the map provided U in Figure 2-1. Information obtained from the National Climatic Center indicates that no other government sponsored long-term data collection programs exist P within the site region.
j
, Inspection of Table 2-1 reveals that temperature data collected at Greenland, N.H. (cooperative observer) and the New Castle Coast Guard Station p are not suitable for statistical analysis of extreme temperatures. The period U of record at Greenland is only 9 years--far short of the desired long-term n
. data record. Intermittent observations at New Castle result in the likelihood L.\
that true daily maximum and minimum temperatures were not reliably observed.
Ii
!j The remaining stationg, Pease AFB, Sanford, ME, and Rockport, MA, were used to develop the analyses presented in this study. Each of these three stations has at least a 26-year data record available for use.
b 2.2.2 Previously Analyzed Data Dry bulb temperature data for meteorological stations in New England I
have been analyzed by Nicodemus and Guttman of the National Climatic Center.
The list of stations considered is presented in Table 2-2(2) . The stations Li analyzed by the NCC do not include RI)ckport, MA, Pease AFB or Sanford, ME.
This NCC analysis forms the foundation for the design basis extreme tempera-
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tures recommended by NUREG/CR-1390.
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r, pj ' The purpose in reviewing data from the NCC study was to establish t) whether stations in relatively close proximity to the Seabrook site and in i_
y a coastal environment were used in drawing the isotherm analyses found in c3 NUREG/CR-1390,and whether a pronounced maritime effect is evident in.
"} New England coastal observations of extreme temperatures. The results of C this analysis are discussed in Chapter 3.
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2.2.3 Representativeness Analysis
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Temperature data for Pease AIB were selected for this analysis on the basis
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LJ of it being the closest station to the site havina the required hour-by-hour temperature data. ' Temperature data from other stations in the site region n
(j were analyzed and compared to the Pease AFB data to demonstrate the regional representativeness of the Pease AFB data. This analysis was based on the LJ following considerations:
(~ e Proximity of measurement e Similarity of measurement topography
(' e Similarity of measured extremes
)
e Similarity of expected extreme statistics (l
(i 2.3 Estimation of Return Period Statistics
, 2.3.1 Assumption of Data Distribution Characteristics Extreme and near-extreme values of climatologital variables are generally
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(! considered to be best fit by the Fisher & Tippett Tyse I and Type II extreme 7
value distributions ( ' . The Type II distribution is appropriate for data
~I with a known upper er lower bound (e.g. extreme wind speeds)(5) . The Type I il' distribution is appropriate for extreme maximum and minimum temperatures.
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' The equation representing the cumulative probability from the Fisher-Tippett Type I distribution is as follows:
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_ x -a) c' F(x) = exp -e l.
where:
'U F(x) is the probability that a selected value of X will
.: not be reached
[7 a is the mode of the distribution i
lo 4 is the scale factor of the distribution r '-
I This distribution was fit to the extreme temperature data according to the procedure developed by Lieblein The computational methodology ti .
(1 followed is described in more detail in the following section.
e, L- 2.3.2 Computational Methodology -
l, The computational methodology followed for determination of 50- and
- 100-year return period hourly temperatures and averaging period temperatures ,
(' is described in this section.
l
{' 2.3.2.1 Hourly Temperatures
/
Computation of the 50- and 100-year return period extreme temperatures for Pease AFB at Portsmouth, N.H. followed the methodology summarized below:
~~a. Pease AFB data were obtained on magnetic tape from the National~~
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Climatic Center in TD-1440 format. This provided a data base consisting of hourly observations of dry bulb temperature.
~~b. The data tapes were reformatted to CD-144 format (one hour of~~
-- data per record).
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} c. c. Each calendar year of data was searched (using the SPSS p;j system ( )) to determine the annual maximum and minimum hourly
.t temperature observations. The chronological order of the observations was preserved during this process.
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~~d. These samples were divided into subgroups of six entries q.~~
'q,, i- . each (plus a remainder group,if required).
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~~e. Each subgroup was arranged in ascending order of magnitude~~
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for the extreme maximum analysis and descending order for '
i L' the extreme minimum analysis.
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~~f. The order statistics weights developed by Lieblein were~~
~~- (_i r, applied according to the procedure outlined in Reference 4.~~
~~g. Temperatures corresponding to return periods of 50- and 100- .~~
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' years were computed.
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~~2.3.2.2 Averaging Period Temperatures t;~~
c, Using the hourly records of observations available for Pease AFB, mean t
( dry bulb temperatures were computed for running averaging periods of 2, 4, 8, 12 and 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months using the SPSS system. If a dry bulb temperature observation was missing in a particular averaging period, the average for that period
=
i was discarded. This occurred only rarely, as will be demonstrated in Chapter 3.
i.
This averaging methodology, for an example non-leap year, resulted in the generation of (8760 - (N - 1) - M) average dry bulb values for each different
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averaging period (where N is the averaging period length and M is the number i
u, of averaging periods discarded due to missing data).
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The dry bulb temperatures for each averaging period for each calendar I' year were searched to determine the extreme =v4== and extreme =4n4==
values for that year. These data sets were then used in the computations t
described in Section 2.3.2.l(c) through 2.3.2.l(g) to yield 50- and 100-year return period dry bulb temperatures representative of the 2,4,8,12
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L and 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months averaging periods. .
bk 2.4 Derivation of Temperature Progression Data Ls The Pease AFB hourly temperature data for the period, April 1,1956 c
[ through December 31, 1981, were further utilized for the generation of several hourly temperature progressions and frequency distributions of hourly tempera- --
(- - tures. Initially, the sets of 24 hourly temperatures comprising the periods .; ,
t; of the five highest and five, lowest 24-hour average temperatures were deter-mined.
(.
1 Since none of'the hourly temperature progressions derived above for the F' five warmest 24-hour periods contained the ==4== hourly temperature of ,
1010 F, an additional hourly temperature progression was required. This hourly temperature progression was determined by analyzing the temperatures recorded for the hours surrounding the hour of the record mar 4== observed temperature.
~~v4=~~
Tn , warmest contiguous 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period inclusive of the hour of the observed temperature was then selected.
A. hypothetical hourly temperature progression was also required to demonstrate the expected temporal variation in temperature during the hottest 24-hour period containing the 100-year return period maximum hourly tempera-
_. ture. Initially, the 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months over the entire 25-year data base which resulted s
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L in the maximum 24-hour average temperature were selected. Since the maximum L
hourly temperature recorded during this 24-hour period was 20F lower than 0
t the 100 year return period maximum temperature, 2 F was added to all hourly 7-temperatures recorded during this period. This resulted in the expected
- hourly temperature progression for the warmest contiguous 24-hours which included the 100-year return period maximum hourly temperature.
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! .. .} .} ( ) J C,,,J e s . .L U t....sJ k TABLE 2-1 CENERAL STATION INFORMATION 1
Location Type Elevation of Station Period of Record Latitude Longitude (ft. mal.) ,,cmpera Tc t ure Data
1. Seabrook, H.ll.* November 1972 - November 1974 42" 54' N 700 51' W 40 llourly (Onsite) April 1979 - June 1982 420 54' N 70 51' W 53
~~2. Portsmouth, N.ll. April'1956 - June 1982 43 0 05' N 700 49' W 111 11ourly (Pease AFB)~~
3. Portsmouth, N.ll. January 1966 - June 1982 43" 04' N 70 42' W 30 Cenerally every three (New Castle Coast hours Guard)
~~4. Sanford, ME July 1953 - June 1982 43 28,' N 70 47' W 280 Daily maximum and minimum~~
~~5. Rockport, MA January 1910 - June 1982 42 39' N 70 36' W 80 Daily maximum and minimum~~
~~6. Creenland, N.ll. May 1973 - June 1982 43 03' N 700 50' W 60 Daily maximum and minimum~~
~~Meteorological tower was dismantled in November 1974. A new meteorological tower was erected in April 1979.~~
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TABLE 2-2 MAINE - NEW HAMPSHIRE - MASSACHUSETTS
- r, STATIONS CONSIDERED IN NCC STUDY
~~MAINE NEW HAMPSHIRE MASSACHUSETTS c.~~
Station Station Station Station Station Station Number Name Number Name Number Name j' 170371 Bar Harbor 270690 erlin 190049 Adams 172426 Eastport 270703 Bethlehem 190120 Amherst
[" Farmington 271683 Concord 190736 Blue Hill 172765 7 ._
173046 Gardiner 272174 Durham 190770 Boston
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4 173353 Greenville 272999 First Conn Lk. 191447 Chestnut Hill O 173897 Houlton 273177 Franklin 191561 Clinton 174566 Lewiston 273850 Hanover 192642 Fall River 7 174927 Madison 274399 Keene 192806 Fitchburg l 175304 M1111nocket 274475 Lakeport 192975 Framingham 176425 Old Town 275072 Manchester 193505 Haverhill
- ,-- 176905 Portland 275500 Mearoe 193713 Hoosac Tunnel ii 176937 Presque Island 275712 L.shua 194105 Lawrence J( 177174 Ripogenus Dam 276818 Pinkham Notch 194313 Lowell 177250 Rockland 195159 Mantucket
'7 179891 Woodland 195246 New Bedford
{j 197370 Shelburne Falls 198046 Springfield 198181 Stockbridge-198367 Taunton 198580 Turners Falls k
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3.0 STUDY RESULTS i
3.1 Representativeness Analysis
'O Pease AFB, the offsite source of temperature data, is located ten miles
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r- north of the Seabrook site, just outside the city of Portsmouth, New Hampshire.
Pease AFB lies approximately five miles inland. The Base and the surrounding fC area is topographically very similar to the area surrounding the Seabrook site ti which lies approximately 2 miles inland. One exception is that a relatively large water body, Great Bay, -lies directly to the southwest of the base. The presence of this Bay may affect extreme temperatures recorded at Pease under
'--. conditions of southerly or westerly winds.
t1 Despite this difference, the representativeness of Pease AFB can be
- demonstrated by comparing the frequency of extreme daily maximum and minimum temperatures. Tables 3-1 presents the frequency of daily maximum temperatures I equal to or greater than 800F and 900F,and daily minimum temperatures less j
than or equal to 100F and 00F for the Seabrook site, Pease AFB and the other area stations.
Pease AFB displays a significantly larger frequency of extreme daily maximum temperatures but an almost identical frequency of exteme daily minimum temperatures compared to the Seabrook site. The Greenland, N.H.
station which is located three miles south of Pease AFB has a similar distri-bution to that of Pease AFB but with a slightly higher frequency of extreme daily minimum temperatures. The percentages for Greenland, N.H. are, however, a based on a very limited number of observations. The Rockport, Massachusetts station, which is located 27 miles southeast of the Seabrook site, has the r
3-1
- -. .i
i
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IL 3 i
~ L:
lowest frequency of extreme daily =mv4== and minimum temperatures in the
' ranges considered. This is mainly due to the close proximity of this station to the Atlantic Ocean, which acts to greatly moderate its temperature extremes.
I Unlika the Seabrook site and Pease AFB, this station does not have intervan-i ing land between it and the Atlantic Ocean for winds from both the north and east directions. The Sanford, Maine station on the other hand is located well -
inland in an area with significantly higher terrain than any of the other stations. The frequencies of extreme daily ==v4== and minimum temperatures are consequently the highest for this station,.as shown in Table 3-1. The inland location of this site greatly reduces the moderating effects of the -
Atlantic Ocean.
iJ ,
Th's representativeness of the Pease data to the onsite conditions is ,
further confirmed by the comparison of the frequency distributions of the entire temperature data base $. Table 3-2 presents such a frequency distribu-tion of hourly temperatures for the entire period of record for the Seabrook site and Pease AFB. The frequency distributions for these sections are very
= -
similar with Pease AFB showing only a slightly higher frequency of hourly tem-parature extremes. The similarily in. distributions provides further evidence of the representativeness of Pease AFB.
3.2 Fif tv and 100-Year Return Period Temoeratures Table 3-3 presents the 50- and 100-year return period ==v4== and mini-mum temperatures computed for Pease AFB. On the basis of the representative-ness analysis discussed in Section 3.1, these extreme temperatures are rea-sonably representative of the site area.
3-2
. - - - - ~ - .
~
I r=
L.
jO Table 3-4 presents the number of missing running averages for averaging L
periods of 1, 2, 4, 8, 12 and 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for Pease AFB for the period, January 1, 1957 through December 31, 1981. The numbers in parenthesis on this table represents the percentage of possible averaging periods which b were missing. The frequency of missing values ranges from 0.2 percent for m hourly averages to 2.9 percent for running 24-hour averages.
i_
The isotherm maps in the NUREG/CR-1390 analysis indicate 100-year
- . return period maximum and minimum hourly temperatures of 106 F and -320F F' respectively. Examination of the data base used in developing these maps i
however, revealed no coastal station within 40 miles of the Seabrook t
site. The closest station to the site is Haverhill, Massachusetts, approxi-u '
mately 14 miles southwest. This station however is located about 10 miles farther inland than the Seabrook site. Proximity to the coastline is a significant determinant of the degree and frequency of temperature
! extremes. This is especially true, and may be clearly demonstrated for, i extreme minimum temperatures by comparing the 100-year return period mini-mum temperatures for pairs of relatively nearby stations - one coastal and one inland-shown in Table 3-5. For instance, in the case of New Bedford, MA, the 100-year return minimum is -19.50F. Comparison with Taunton, MA (about 20 miles inland from New B,edford) reveals that Taunton's expected minimum temperature for the same return period is almost 18 F colder.
Similar pronounced differences in extreme minimum temperatures are found north of the Seabrook site. These may be seen by comparing Portland and Rockland values (both coastal stations) with those computed for stations farther inland such as Lewiston and Gardiner. (Lewiston and Gardiner are approximately 20 and 25 miles inland, respectively)?
3-3 i
~~' ~ ^ --~~
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t
'. The effect upon extreme ==v4== temperatures appears less pronounced.
~~- ' Nantucket, MA, of course, shows a very significant maritime influence on both~~
~
==v4-= and =4n4== temperatures with a 100-year return values of 98.5 and
-13.10F, respectively. This is the most moderate expected 100-year return
=4 n 4 == temperature and the third lowest maximum temperature of all of the
~
48 stations analyzed by Nicodemus and Guttman (1) in the states of Maine, New -
Hampshire and Massachusetts.
i 3.3 Temperature Progression 2 -
l Table 3-6 presents the hourly temperature progressions for the five L
coldest and warmest 24-hour periods for Pease AFB observed for the period _-
i. April 1, 1956 through December 31, 1981. The warmest 24-hour period averaged _
~~- 86.620F and occurred from August 2, 1975, hour 4 through August 3, 1975, hour~~
3. The coldest 24-hour period averaged -8.080F and occurred from January 8,1968 hour0.0228 days 0.547 hours 0.00325 weeks 7.48824e-4 months 11, through January 9, 1968, hour 10. The warmest 24-hour period was used to generate the hypothetical hourly temperature progression for the varmest contiguous 24-hours 'containing the 100-year return period ==v4==
hourly temperature of 102*F. Since the observed warmest 24-hour period contained.a ==v4== observed hourly temperature of only 100*F, each hourly temperature was increased by 20F to produce an hourly temperature progression
'which would contain a ==v4== hourly temperature of 1020 F, the 100-year return ==v4== hourly temperature for Pease AFB. Table 3-7 presents the hourly temperature progression for the warmest contiguous 24-hours contain-ing the ==v4== observed hourly temperature,1010F recorded at Pease AFB.
This 24-hour period averaged 83.880F, and began on June 30,1964 hour0.0227 days 0.546 hours 0.00325 weeks 7.47302e-4 months 15 '
and ended July 1, 1964 hour0.0227 days 0.546 hours 0.00325 weeks 7.47302e-4 months 14. This 24-hour average was slightly cooler than the fifth warmest 24-hour period listed in Table 3-6.
3-4
- -- - _ , . - . . . . . - . -.--.. -. ==.
TABLE 3-3 SEABROOK EXTREME TEMPERATURE ANALYSIS MAX 1 MUM AND MINIMUM TEMPERATURES FOR 50- AND 100-YEAR RETURN PERIOD FOR PEASE AIR FORCE BASE
~~Upper and Lower Temperatures ( F)~~
Averaging Period Return Period (years) Maximum Minimum Hourly 50 101 -19 100 102 -21 2-Ho ur 50 100 -19 100 102 -21 4-Hour 50 100 -18 100 101 -21 8-Hour 50 98 -18 100 99 -20 12-Hour 50 95 -17 100 96 -19 24-Hour 50 80 -13 100 89 -16
~~DATA BASE: January 1, 1957 through December 31, 1981~~
~~s _~~
~~TABLE 3-2 FREQUENCY DISTRIBUTION~~
~~- 0F HOURLY TEMPERATURES FOR SEABROOK AND PEASE AFB~~
~~Frequency of Frequency of Temperature Occurrence (%) Occurrence (%)~~
c- Interval (deg. F) Seabrook Pease AFB I
(-16) - (-12) 0.0 40.1
(-11) - ( -7) < 0.1 <0.1 il ( -6) - ( -2) 0.2 0.2
.'.;i ( -1) - 3 0.5 0.4 4 - 8 0.8 1.0 q 9 - 13 17 19 L* 14 -
18 2.5 2.8 19 -
23 4.0 4.2 24 - 28 5.0 5.7 P 29 -
33 8.2 8.4 l/ 34 - 38 9.9 9.5 39 - 43 10.0 8.6 44 - 48 8.7 8.0
! 49 - 53 8.8 8.2 54 - 58 9.0 8.5 59 - 63 9.4 91 64 - 68 8.3 8.5 ,
69 -
73 6.6 6.7 74 - 78 3.7 4.3 79 -
83 1.9 2.5 84 - 88 0.8 1.2 89 -
93 0.2 0.3
,_, 94 _
98 0.0 < 0.1 99 -
103 0.0 <0.1
~~DATA BASE: Seabrook: November 1, 1972 - November 30, 1974 (inclusive) and April 1, 1979 - June 30, 1982 (inclusive); 46,003 valid hourly observations.~~
Pease AFB: April 1, 1956 - December 31, 1981 (inclusive);
225,093 valid hourly observations.
a O
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+
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em O TABLE 3-3
/.3 SEABROOK EXTREME TEMPERATURE ANALYSIS
'q MAXIMUM AND MINIMUli TEMPERATURES FOR 50- AND 100-YEAR RETURN PERIOD i:
FOR PEASE AIR FORCE BASE *
/ !.m Temperatures ( F)
Averaging Period Return Period (years) Maximum Minimum l[m 101 -19 Hourly 50 li 100 102 -21
\,;
O 2-Hour 50 100 -19 100 102 -21 (i'
6
~'
4-Hour 50 100 -18 100 101 -21 8-Hour 50 98 -18 1 100 99 20 Ir
., 12-Hour 50 95 -17 100 96 -19 90 -13
[' 24-Hour 100 50 92 -16 ti e.
~~DATA BASE: January 1,1957 through December 31, 1981~~
~h 9
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jj TABLE 3-4 SEABROOK EXTREME TEMPERATURE ANALYSIS
!I NUMBER OF MISSING RUNNING AVERAGES
'U FOR VARIOUS AVERAGING PERIODS FOR PEASE AIR FORCE BASE
~~l p Averaging Number of Missing~~
~~j Period (Hours) 1 427 (.2%)~~
~~I i ., -~~
2 784 (.4%)
r i;-tI
" 4 1422 (.6%)
!. 8 2590 (1.20 ilIu 12 3665 (1.7%)
f' 24 6537 (2.9%)
II
~
~~DATA BASE: January 1, 1957 through December 31, 1981 l.~~
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~~TABLE 3-5~~
~~..)~~
100-YEAR RETURN PERIOD MAKIIRIM AND MINDEBt TDfERATURES*
FOR SELECTED NEW ENGLAND STATTONS ,
( .,
LOCATTON 100-TEAR RETURN FERIOD
- Elevatten CENERA!. PER!00 TRARS OF TetERATURE DATA TDFERATUtt$ (deareas F)
Latitude lanaltyde (ft. mal.) 0F RECORD Maximum MLa tmum . Maximus h f]l '
1TJ1[2E.
1896 - 1976 81 80 106.3 -49.3 Cardiner. ME 44' 13' N 69' 47' W 140
.q 4: 103.9 -37.6 Lew1.rton, ME 44' 06' N 70' 13' W 180 1896 - 1976 81 81
{
"I Pstttand,at 43' 39' N 70* 19' W $7 1872 - 1977 104 106 104.8 -32.4 44' 06' N 698 07' W 40' 1937 - 1976 38 34 104.3 -31.2 Beckland. ME C
42' 22' N 71' 02' W 13 1873 - 1977 103 1c5 103.3 -20.8 sostem. MA I
i Farmingham. MA 41* 17' N 71* 25' W 170 1893 - 1976 84 83 103.4 -32.2 41' 15' N 70' 04' W 43 1887 - 1977 91 90 98.5 -13 1 Nantucket. MA 41' 38' N 70' 36' W 120 1893 - 1976 84 81 104.7 -19.5 New Bedford MA i
41' $4' N 71' 04' W 20 1893 - 1976 to 84 103.6 -37.3 Tauntos. MA Ia
~~Beforesee (2).~~
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TABLE 3-6 t PUBLIC SERVICE CORFORATION OF NEW RAMPSHIRE SEABROCK STATION 17 NITS 1 A!!D 2 m
I
TIVE Col. DEST 24-HOUR PEltIODS FIVE WARMEST 24-ROUlt PERIODS r! Average -8.08 -7.12 -5.50 -2.70 -2.50 Average 86.62 85.87 85.25 84.25 83.91 i Year 1968 1957 1980 1967 1981 Year 1975 1977 1964 1978 1981
~~1. Period Ends Jan 9 Jan 15 Dec 26 Feb 13 Jan 5 Period Ends Aug 3 Jul 21 Jul 19 Jul 22 Jul 9 Hour Ecur~~
!, M M
' 01 01 02 02 r, 03 03 j 04 04 74 L, 05 05 77 06 -2 -4 06 82 07 -5 -2 07 85
.: ' 08 -7 -4 08 90 j 09 -7 -4 09 92 -
1J 10 *
-7 0 -2 10 97 11 -6 -7 1 -2 11 99 88
. 12 -5 -5 2 1 12 100 90
}
13 -4 -4 2 2 13 100 93 91 t'
14 -4 -4 3 3 14 100 94 93 15 -4 -4 3 3 15 98 94 93 16 -5 -5 3 2 16 97 94 94 93 17 -6 -5 2 0 17 92 92 92 91 18 -7 -7 0 0 18 87 89 89 86 I' 19 -8 -7 -1 -2 19 84 87 87 85 87 20 -10 -7 -1 -2 20 82 85 85 84 86 %
21 -10 -7 -2 -5 21 80 83 84 82 82 22 -10 -4 -7 -3 -7 22 78 82 84 82 80 23 -10 -7 -6 -4 -7 23 77 80 82 82 80 00 -10 -8 -5 -5 -7 00 80 79 81 82 79 01 -9 -10 -5 -6 -5 01 77 79 80 80 78 02 -9 -11 -5 -7 -5 02 75 78 79 79 77 i
03 -10 -13 -5 -8 -5 03 76 77 79 79 75 04 -9 -14 -5 -8 -4 04. 77 78 79 74 05 -10 -15 -4 -8 -4 05 77 77 78 75 06 -10 -15 -9 06 77 76 78 77
- 07 -12 -16 -9 07 80 78 79 79 08 -10 -14 -7 08 84 80 81 80 09 -9 -12 -3 09 87 84 82 82 10 -7 -8 10 91 90 85 85 11 -5 11 95 92 90
- 12 -1 12 96 94 89 13 0 13 96 93 14 1 14 98 95 15 0 15 98 94 16 -3 16 94 17 -4 17 93
.- 18 -4 18 90 19 -4 19 20 -2 20 21 -2 21 22 22 23 23 DATA BASE: April 1, 1956 through December 31. 1981
^ {
. -_ _______-_-________________:__ _ 1
^l
.1 !
u TABLE 3-7 0
,i .! SEABRROK EXTREME TEMPERATURE ANALYSIS HOTTEST CONTIGUOUS 24 HOURS IN ASSOCIATION WITH n THE HOITEST ONE-HOUR TEMPERATURE r[j - OBSERVED DURING 1957 THROUGH 1981 AT PEASE AFB
, YEAR DATE HO"R TEMPERATURE (OF)
(;
1964 June 30 15 89
'~
16 89 17 89 18 85 m 19 81 lI 20 80 21 77 22 76 23 76
!1 i July 1 00 74 1 76 M 2 75 1'
tj 3 75 4 74 5 73
! 6 76 ,
7 80 8 88 c 9 92 L' 10 93 11 96 j 12 98 j 13 101 14 100 1: 4
.e-
. i a,
1 3
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l 4.0. CONCLUSION The 50- and 100-year return period maximum and minimum temperatures
~
f recommended- for use in the' confirmation of the adeq'uscy of safety-related equipment design are as follows:
Temperatures ( F)
. Averaging Period Return Period (years) Maximum Minimum Hourly' 50 101 -19 100 102 -21 2-Hour 50 100 -19 100 102 -21 4-Hour 50 100 -18 100 101 -21 8-Hour 50 98 .-18 100- 99 -20 12-Hour 50 95 -17 100 96 -19 24-Hour 15 0 88 -13 100 89 -16 These temperatures are based on data collected at Pease AFB which are reasonably representative of temperatures observed at the Seabrook site.
The 100-year return period maximum and minimum temperatures recommended by NUREG/CR-1390 for use at the site do not adequately consider the moderating effect of water for New England coastal sites. ExaLination of data presented in Table 3-5 resulted in the conclusion that the moderating effect is very pronounced in its effect on extreme minimum temperatures and not as important for extreme maximum temperatures.
4-1 1
l U
I!
(_
~~5.0 REFERENCES~~
r fJ 1. Nicodemus, M.L. and N. B. Guttman, " Probability Estimates of Temperature Extremes for the Contiguous United States", NUREG/CR-1390, National . .
<- Climatic Center, Asheville, N.C., May 1980.
I
2. Private Communication with M.L. Nicodemus, Statistical Climatology Branch, National Climatic Center, Asheville, N.C. , October 13, 1982.
l' L 3. United States Weather Bureau, " Fitting of Climatological Extreme Value Data", Climatological Services Memorandum No. 89, Washington, D.C.
p August 11, 1961.
[' 4. Thom, H.C.S. , "Some Methods of Climatological Analysis", Technical Note No. 81, World Meteorological Organization, Geneva, Switzerland,1966.
Thom, H.C.S., " Distributions of Extreme Winds in the thited States",
(? 5.
Journal of the Structural Division, Proceedings of the .'merican Society of Civil Engineers, April 190.
U 6. Lieblein, J. " Efficient Methods of Extreme-Value Methodology", National Bureau of Standards, NBSIR 74-602, U.S. Department of Commerce, Washington, D.C. 1974.
[a;
~~7. University of Kansas Academic Computing Center, Statistical Package for~~
~~', the Social Sciences Batch System-Release 9.0, Lawren'ce, Kansas, December 1981.~~
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-._. .- - - - - . , - . - - . .

ML20073M475

Contents

Text

1.0 INTRODUCTION

4.0 CONCLUSION

5.0 REFERENCES

1.0 INTRODUCTION

SUMMARY

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5.0 REFERENCES

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ML20073M475

Text

1.0 INTRODUCTION

4.0 CONCLUSION

5.0 REFERENCES

1.0 INTRODUCTION

SUMMARY

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5.0 REFERENCES

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