ML19257A207

Preoperational Sound Levels.

ML19257A207
Person / Time
Site:	Sequoyah
Issue date:	12/27/1979
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML19257A205	List: ML19257A204 ML19257A206 ML19257A207
References
NUDOCS 8001020477
Download: ML19257A207 (14)

Text

9s SEQUOYAH NUCLEAR PLANT PREOPERATIONAL SOUND LEVELS 1671 348 sco1oso Y<h

TABLE OF CONTENTS Page Introduction ........................................... 1 Noise-Sensitive Land Uses............................... 1 Pre'perational Sound Survey............................. 2 Operational Noise Impacts............................... 3 Conclusions............................................. 5 1671 349

Introduction This report is based on sound surveys conducted near the Sequoyah Nuclear Plant on Saturday, September 1, 1979, and on estimates of sound generated by major noise sources at the plant. Since construction activities were not taking place on this day, the data represent pre-operational sound levels at this time.

For purposes of this report we have assumed that both generating units would be operating and that the cooling towers would be operating continuously during the summer months. However, this is a multimode plant (open, helper, and closed modes) and we anticipate that in actual practice the plant will operate in open mode about 80 percent of the time, helper mode 16 percent, and closed mode about 4 percent of the time.

Noisc-Sensitive Land Uses Most of the land areas outside the plant boundary and within a one-mile radius of the plant appear to be rural residential or undeveloped water-f ront properties. There appear to be 20 to 30 homes within the one-mile radius. Some of these are on lakefront property.

Within the two-mile radius there are over 140 homes, one church, and a peninsula of Harrison Bay State Park. There are no schools or hospitals within the three-mile radius.

The nearest residential area to the plant transformers is along Igou Ferry Road west of the site. The nearest residence to the cooling towers seems to be on Chigger Point across the lake to the east.

1671 350

Preoperational Sound Survey TVA conducted sound surveys at three selected community locations near the Sequoyah Nuclear Plant site on Friday, August 31, and Saturday, September 1, 1979. The locations of the sampling points are shown on Figure 1.

The August 31 survey data represent the sound environment durine construction activities at the site. These data were nec used in impact assessment.

The survey conducted on Saturday, September 1, 1979, provided data which can be used as preoperational or baseline data for impact assess-ment. No construction activity was in progress at the project on September 1.1/ Thus the data represent current, typical summertime environmental sound values in the vicinity when no construction or production noise is occurring at the TVA plant site.

Tape recordings were made at each survey location. The time of day was randomly selected. Recordings lasted 15 minutes at each location. Both daytime (7 a.m.-10 p.m.), and nighttime (10 p.m.-7 a.m.) recordings were obtained for the preoperational sound surveys (September 1). Only day-time values were obtained for the construction sound surveys (August 31).

Tapes were computer analyzed to yield equivalent sound levels for daytime periods (Ld), nighttime periods (Ln), and for the day-night composite (Ldn).2/ While survey crews were at each location they also made baseline octave band sound pressure level readings.

1/ The last work shift ended at 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br />, Friday, August 31, 1979. In order to avoid shift traffic noise, the baseline surveys did not start until 0015 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />, September 1, 1979.

2/ The instrumentaion system used in measuring baseline noise levels consisted of a Geaeral Radio Model 1982 sound level meter and a Nagra model E single track, reel to reel, tape recorder.

(continued next pace) 1671 35i

Con't Footnote 2 continued:

The General Radio Model 1982 is a precision sound level meter and analyzer using a 1/2 inch flat random incidence microphone.

The frequency range is from 10 HZ to 20 KHZ at the 3dB down points.

This instrument meets the Ansi Standard Sl.4-1971 for a type 1 instrument. The signal output of the 1982 SLM is fed into the Nagra Model E for data recordings.

The Nagra Model E tape record 4 r is a portable pnit, single track, with a frequency response of - 2dB from 50 HZ to 15 KHZ using Scotch 212 low noise tape. This component with the GR1982, establishes a system that provides recordings of sound data over a frequency range of 50 HZ to 15 KHZ. Calibration of the system is conducted using a GR1562 microphone calibrator at a level of 114 dB at 1000 HZ.

I671 35g

The survey data are summarized in Table 1. The baseline equivalent sound levels are rather high. On the west side of the plant site, baseline Ldn values slightly exceed 55 decibel maximum icvel identi-fied by EPA as requisite to protect public health and welfare (Ref. 1).

The baseline Ldn at Chigger Point, across the lake is only one decibel below the EPA level. This community-generated sound seems to originate predominately from insects and birds, additional contributors include motor vehicles, boats, aircraft, and general community activity such as lawn mowing. The activities were normal typical community activities, and the results were not based on any unusual activities.

Operational N61sc Impacts The two major continuous noise sources considered in this analysis were the switchyard transformers (two banks of three each) and the two natural draft cooling towers. Although the transformers do not emit pure tones, they will have a spectral characteristic which might cause the sound to stand out against a random background. Using published values for noise emission from large cooling towers (Ref. 2) and TVA survey data on transformer noise emission (Ref. 3), operational sound levels at the survey points were estimated. Data are presented in Table 2.

I671 353

_4_

In this analysis no consideration is included for attenuation or reflection from nearby surface features such as building, water surfaces, and hills. Obviously, such features can strongly influence propagation of sound waves. For example, the power station buildings will intercept sound traveling from the transformers toward Chigger Point. This will have a lowering effect on operational sounds at Chigger Point. Conversely, operational sound will be reflected by the water surface of Chickamauga Lake as it travels toward Chigger Point. The result could be enhanced sound transmission to Chigger Point.

The effects of the estimated transformer and cooling tower sound levels on the present preoperational (baseline) sound levels are summarized in Table 3.

The data show that transformer and cooling tower sounds will some-times be audible offsite. Transformer sound will prevail over cooling tower sound at areas on the west side of the plant site, whereas, cooling tower noise will prevail to the east.

Other continuous noise sources not included in this analysis were the building ventilation fans, the intake cooling water pumps, and plant vehicle traffic. TVA experience indicates that these are minor noise sources and should exert little, if any, effect beyond plant boundaries.

Intermittent sound sources will include audible warning systems, plant paging and code-call systems, emergency support systems (e.g., generator and flood pumps), and heavy maintenance equipment. Unfortunately, we do not have a data base on these sources.

I671 354

_5_

Two intermittent and infrequent, but significantly loud, noise sources are the air-blast circuit breakers (ACB) and the steam vents.

A one month sample of the ACB records showed that they were exercised approximately 45 times. An ACB underload will generate about 140 decibels of impulse noise at a distance of 50 feet. Sound generated during steam venting is a function of several variables including steam pressure and valve geometry. An estimate of sound emission from the Sequoyah plant vents is not available at this time. We have unofficial data from Ontario Hydro that a sound level of about 84 dBA might be expected at a' distance of 2500 feet from a superheater pressure valve venting to atmosphere under 2300 psi steam pressure. Using these sound levels for circuit breakers and steam vents, we can estimate corresponding sound levels at the points of interest around the Sequoyah plant site.

These are shown in Table 4. Sound levels of this magnitude will be distinctly audible offsite and will probably not diminish to inaudible levels for distances up to several miles.

Conclusions Although baseline sound levels are relatively high, sound from the transformer and cooling towers will sometimes be audible offsite. However, since this is a multimode cooling system (open approximately 80 percent of the time helper approximately 16 percent of the time, and closed approximately 4 percent or the time) the amount of time that noise will be emitted from the cooling towers should be minimized. These baseline sound levels will be somewhat augmented by sound from lesser, but yet unquantified, plant sources (plant traffic, communication systems, etc.).

Sound from the intermittent and infrequent use of both the air blast circuit breakers and the steam vents will be clearly audible offsite.

1671 355

References

1. Information on Levels of Environmental Noise Requisite to Protect Public Health and Welfare With an Adequate Margin of Safety, Report No. 550/9-74-004, USEPA, Arlington, Virginia, March 1974.

2. " Noise Prediction Techniques for Siting Large Natural-Draft and Mechanical-Draft Cooling Towers," G. A. Capano and W. E.

Bradley, V. 38, Proceedings of the American Power Conference, 1976, pp. 756-763.

3. " Noise Survey and Impact Report, Volunteer 500 kV Substation Site," C. C. Thornton, TVA Industiral Hygiene Branch Technical Report, IH-76-5, September 24, 1976.

1671 356

TABLE 1 SITE Sequoyah Nuclear Plant Prc.

E SUMMER NOISE SURVEY DATA Es,3jiC;\r ,

ri.)lF6 LO C ATION LEVEL 00SPL- dD- OCTAVE BAND CENTER FREQUENCY

.cl Leg Ldn dBA 3f.5 G3 125 250 500 IK 2K 4K 8K 16K Nortnwest of site. Approx.

1. 2400 tt. fron switchyard, 4200 ft. Ld 47 43 51 49 44 43 40 33 30 33 37 32 '

f ro : c towers. Sat., Sept. 56  !

1, oldolines 1144 hrs. Ln 50 50 49 49 44 44 41 30 46 42 41 35 1lest of. Site. A 2400 ft.

t rom . su ttchvard , porox .300 feet fron Ld 48 43 47 49 45 39 3 36 27 28 g j u'g g e gat., dept. 1, 56 36 39 37 Ln 50 49 47 49 42 34 34 25 44 42 45 40 i

iAcross river at uiu er ro utt .

3- 4;0"0 oz.tt. 5700 ft. frb7. evitchyard, Il~I t.d 4 5 38 40 42 40 37 34 3,

trom cooling towers, dam. r- 54 28 27 31 32 23 Sept. 1, 00L5 and 1043 hrs. 46 47 42 44 Ln. 42 33 24 16 35 44 43 26

_Ld -

1. n

• 1 S ne location as :po . I aouve. vata? ' - ~ ~ ~

57 I

rent e ents conditions during 55 52 54 44 39 37 28 28 47 1" norna conc riiction. Fr2 day, Ang. - - -Ld 49 52 31, 1979, 2057 hrs. -

Ln iS ar.e location as .o . 2 aaove. Una repre DorraE,construction cuts conditions duting L.d 48 47 57 57 46 43 43 33 I Fri., Aug. 31, 41 37 41 26

,19P). 2024 hrs.

do ,

h.I

~

~

N

D r, q g 63 i

~ '

D 6D '4 r Table 2 ,a 1) g d Estimated Operational Sound Levels Ne.ar Scouoyah Nuclear Plant Cooling Tower and Transformer Sound Es timated Operational Sound Levels , dBA, location of Assessment Point Coolinn Towers

• Trans formers ** Combined No. 1 on map. Residence near

• plant boundary N.W. of site.

2400 feet f rom switchyard, 4200 feet from c.t. 50 53 55 No. 2 on map. Residence near ,

plant boundary W. of site.

2400 feet f rom switchyard, 4300 feet from c.t. 50 53 55 No. 3 on map. Residence on

'. Chigger Point S .E. o f plant.

5700 feet from switchyard, 3700 feet f rom c. t. 51 45 52 a

• llowever, since this is a multimode cooling system (open mode approxi-mately 80 percent, helper mode approximately 16 percent, and closed mode approximately 4 percent of the time in the summer months), the amount of time that noise will be emitted from the cooling towers should be minimized.

• • The transformers will emit a tone having spectral characteristics rather than pure tones.

1671 358

Total Predicted Sound Levels From Cooling Towers and Transformers Sequoyah Nuclear Plant Summer Cooling Tower C.T. Plus Transformer Transformer Combined C.T.

Baseline Sound Level Baseline Sound Level Plus & Transformer Sound Level Baseline Plus Baseline No. 1 on Map Ld 47 50 52 53 54 56 Ln 50 53 55 56 a

Ldn 56 59 61 62 m

u No. 2 on Map Ld 48 50 52 53 54 56 Ln 50 53 55 56 Ldn 56 59 61 62 No. 3 on Map Ld 45 51 52 45 48 53 Ln 48 53 50 54 Ldn 54 59 56 60 N

~

LT1 m

e a g 1 Table 4 0

_oc w J-{ ,

Estimated Operational Sound Levels Near Sequoyah Nuclear Plant Air Blnst Circuit Breakers (ACB) and Steam Vent Valves Estimated Operational Sound Levels, dBA Location of Assessment Point ACB (Impulse Sor d

• Sin.le Stea- Vent No. 1 on map. N.W. of plant.

2400 feet from ACB. 2800 feet from vents 107 83 No. 2 on map. West of plant 2400 feet from ACB. 3100 feet from vents. 107 83 No. 3 on map. Across river at Chip,ger Point. 5700 feet from ACB, 5400 feet from vects. 99 78

• A random monthly sample of records showed that the ACG's were exercised approximately 45 ti.nes.

1671 360

jh ^

u %, , l f fem [] qfg 9 .,. ,,Mggpom MSMt W yr T VJ Q~~( Q>>kwl%.,,.. 'o - - - MQN -

n. N:,t,:T

,, q g, a y,, a , :x ..

r, j,; , ' < + '- -ij Y <O w~ w k,:1 ,.s u s  : ;r +

+

?;e.y% n;pb; .": pW, JJyg g v .

.si 'w . e. m .-

.(..,

s.

9

.' W

. ~. . . 1 .

.;M Sh

' . A . J Ej ,',(,,,[ L i

~

M. *g%.

1- 'i

. '.l;lj[e. 6

" 4 e.%v;;:L -

• s 'c f s M%m.%~ ' .m m ".  ; % * .x 4 ng~ M, b^l%. .." Y ;Q 43fh.4

') >

2, 4 ~ &ws p? ' R-

~fW,.' cn , y.m;-N h ~

wu th.,3W2.w x .

.s.

' . s *.,

W +y,B, f ' ^

• w a(p . '- .r a.4?v -v u.a--~M 4 , m.,

/ *e.' 'Ad *- g 4 k p8 . a' ;'s. .

fQ  ? ' 1 -'i 7 )Q ll1 $j.9. ,0 f,

h f

'W

' . s}. G' & f, <j *

G.

k; ? '. YL '

+ ; G; t - <

e -.

< , ' < n&. y : <.4 ',

w  ;.>d u.. , t..1 , u, A .. 1: '"

- r. r, . 2~, e rq . . -

%, . f ,x s'.

1. s. p .

g. r < p , t -

. , .y p f , - w %<t ,

x3. , % v.- t, . , . . ,

.s ~e ~r~ -

.4, g e . o .- -

, ;. y

• v, 4,( ),,

f, ~. <m - ,s .g , ,

.a g. c .-

+

g g 1. ,g ' w '

, s

-9, y' .k:. i, Y ,.

.*C . < s f ,. ,

, ./

j .

q ~'

/.o .s <j . ? %]f y1 ,.[y,,?- Sb. ; m s; a , , '! "

.,4

,P,Qe.

v.

ht A

- e WoD n" 'h\ . N L ,

-l l

-[~h,%

! ^Tl .*c!

-rm --^u .

~..

)< Q$

"~>n Am f:,,..-

.a -t . , , .. , -

~' 8..:. < ? .

}

y% .

wt / s '-- -

%m,,%a .,q$M? -l m

k .a l.,. ..

~ w +, , .d. !. s}. , h.; am s

n w .w;w .s s.;A.

.n:

kt,/. s.sv  : g, e, , ' A . q,.g a'* A e.

,e f q . * ., ?< v i m 2

. g.

$8 C vmx.Mx. w.g. }yq yOc ms . . . - +

.c t h ,7

.,(f atf N y. t.-# ^ 4,4

.1y y

}, ' **

Q. Q , *ghd , e .t~~L*R

_- 7 '\ _

m

, n.:cy

\. -

. y./ , . .

y. yh. y s r,

n. o g ,, y g,py,

s. - *

..s c s >A A. -

rm o, y ./ .j\ j t.

..t

.b-j ,

~, ,

3 i

, r n '. p s., -

{M, ~,. w J,p , q 6

3'

~

'r/ e, j 7. . : n - - -

.;- g.{A

.3 g -

g s ' 4' 0:,

.s sg Na.f - v, -,K[s, ic<-

oys e i 3

g, " 4.O h ; mg ,p a s .

g..,- a pP ,--

, 4s ,g A , ,spte .

, 1 ,

.9, s .;

. st 3 p . , ,

,v.,,,, y .e. .,s. . . . ,

.. -=,7 g 'er f, f k * *

, 4 E W, M': ='t b r.,,r 6 - C, 3 ':

V 3 , .

+,

na,,

. ?c

= A.p

,,,3 gq , n' y '

m q

g.

u y .A 2 ~' =, ; 4 w -f ,. e s

i

. t. V ,

e '%,

/

3 t

, e N, . .% , '

..p #g...

>r' ,

,IN

!?; .% .- /- .7 , p,.,,, ~<

g-v "-

% ~

, f; t v#

c.,

~

I/

4 ig {'S ..

,, y 9,3 h e

[I .-,g 3'- f-5, .o,. Y ,;,

g .g s, -# s. . .. ,

,s  ?+ A ' v. *

% * $.7 c s. u,,l .c g/,h,. .. y o  ; ,,

,n

-v m A- 7 ,9,

,.,..,,..a-y 4 <

f. s ..s, p 4. .; *

<. 1s s,g <s , %

~31

, . -a zs

.i 1 ,

w

.,3 .

m-A <

p: r -~ ^ a r* ,j, *' q,.?- '"_,'*m' 3'- ,-

- , /m 's e1 % - [. . ' ,s.nm . . ' . ,

v W . % **'M.; y- s mw

~- C '

,e,,-r

g y) pr. p ' , .

~

e 's . J *

r. .

, x k. y; g. 't _ . ,) { p- N '- s, -  ? .r,.

• q :1i 3

s.

1 ' 1. - Y' ,'? ,. m@' *

}--[','E %. ,y Ov h .4 '

j 's

.i'

',.0 11

t.  ;

5f L /g,

.. ) j

., g .,,

3 J A,Q, . V, 1:%"g g

'$ T W.b Vf ' ,

.s jt_

z

'  ;d & ;!q J .O M :,N .MJ &

[; M x M - Q,yg  %  : -

M<? 94 4 $

^* ;q&54Mn a -

t -

. / gV@.w h ! 'Q'%' g;s us.7 M., W: %w Q~.w. N w

• Y

.- f ?I?

N g y i4dt

. mn? w Q ;u. *~l.lsq N d' '

Figure No. 1

\

, - %q,Q E,;

/; ': '

g&l 1 / ;,' t ej$p"$v.m$t Mjr@

U M M ,,{ { Q hgg.

Qp ,%g[pe h M -h ' } Locations of sound analysis [ .$.

I?fC 'Q  % p points near Sequoyah Nuclear p .

' Y'V k plant August 31, Sept. 1, 1979 l- Muf 'J ', W"37

~

QML Q , 3 ,.g n p f s

' [q[p N.

w-

-, Q!f*

%.4@'M q 1671 361