ML17138B713
| ML17138B713 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 01/07/1981 |
| From: | Lehr J Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17138B712 | List: |
| References | |
| ISSUANCES-OL, NUDOCS 8101140017 | |
| Download: ML17138B713 (9) | |
Text
UNITED STATES OF A"iERICA N""LEAP, REGULATORY CO!l.'!SSION BEFORE THF. ATOMIC SAFETY AND LICENSING BOA.,D In the Matter of PEfi"iSYLVANIA POli'ER A"D ALLEGHENY ELECTP,IC (Susquehanna Steam
- Station, Units 1
)
)
8 LIGHT COl'iPA")Y
)
)
COOPERATIVE, INC.
)
)
Electric
)
and 2)
Docket Nos.
50-387 O.L.
50-388 O.L.
AFFIDAVIT OF JOHN C.
LEHR I, John C. Lehr, being duly sworn, dispose and state:
By whom are you employed, and describe the work you perform?
A:
I am employed by the Environmental Engineering Branch, Division of Engineering, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission.
A copy of my professional qualifications is attached to my affidavit, filed December 2, 1980.
Have you read "Applicants'tatement of Material Facts as to which There is no Genuine Issue to be Heard (Contention 17)", filed December 5, 1980 and the documents attached
- thereto, including the affidavit of Robert F.
Lehman?
A:
Yes.
lJould you describe the scope of the subject matter addressed in your affidavit?
A:
Yes.
I will address the likely levels and. potential for impact of audible noise that may result from operation of the transmission lines associated with the Susquehanna Steam Electric Station.
Do transmission lines of the type associated with the Susquehanna plant produce audible noise?
A.
Yes, but only under certain environmental conditions.
The lines proposed for use by Applicants are designed for alternating current (AC) transmission and are further classified by their maximum design voltage, 550 kV, as "extra high voltage" (EHV) lines.
The alternating current transmission lines associated with the Susquehanna plant dissipate energy from the surfaces of the conductors via a mechanism known as corona loss.
This loss occurs by ionization of air in the immediate vicinity of the conductor surface when it is energized, due to large potential differ-ence between the conductor and the air.
The design of modern EHV transmission lines is such that this loss is negligible under fair weather conditions.
- However, when the conductor surface becomes
- wet, as during fog, rain, ice or snow, the rate of corona discharge is increased.
Corona di charges result in audible noise.
It is only during wet weather conditions that alternating current transmission lines wi 11 produce audible noise.
g:
h~ould you characterize the noise that is typically produced by EHV AC transmi ssi on lines?
A:
The audible noise produced during wet conductor conditions is characterized as buzzing, hissino and/or crackling sounds, with a low frequency hum, which may have pure tones associated with it.
This sound fluctuates to a greater extent than many other environmental noise sources 1
~ -.
For corona audibl e noi se, one source2 1 ists a range in the 1
2
.'noise,leve'1 of 40 dBA taken as a difference between the noise level exceeded 10Ã of the time (i.e., the L10) and the noise level exceeded 905 of the time(i.e., the Lg0).
(Other fluctuations in noise levels.
cited ranged from 7 dBA for a shopping center to 22 dBA for an airport.)
The typical noise levels produced by corona discharge under wet conductor conditions depend on a number of environmental and design conditions, such as conductor wetness, air temperature, relative humidity, the condition of the conductors, and the size, number and confiquration of conductor bundles and lines Levels of audible noise have been 3,4,5 reported for EHV lines that are believed to represent designs that are common in transmission systems today.
Bragdon and Miller2 cite a
value of 59 dBA at a lateral distance of 50 ft from the line.
Perry
'eports for a 3 phase 525 kV operating voltage line with two 1.602 in.
diameter subconductors per conductor, that the audible noise during continuous rain at a lateral distance of 100 ft from the center phase can be statistically described as follows; the noise level exceeded
75K of the time was 52.5 dBA, the level exceeded 50;-.'f the time was 54.4 dBA, and the level exceeded 5l of the time was 58.2 dBA.
(These measurements are the results of field studies.)
Applicants have calculated noise levels at the edge of the transmission line rights-of-way ranging from 46.3 dBA to 57.l dBA for 525 kV energized voltage under wet conductor conditions.
The average value of audible noise for this condition over all transmission line segments is 52.5 dBA, with a modal value of 53.7 dBA.
Can you describe the potential for impact on people that these noise levels represent?
A:
The potential for impact must consider a variety offactors including the nature or character of the noise, the background noise levels, the frequency, duration and time of occurrence of the transmission line
- noise, the level of the transmission line noise, the distance from the lines to areas of human activity, and the nature of human activities at these locations.
The scope of potential impacts that may reasonably be considered are speech and activity interference, disruption of sleep, and general annoyance.
While the threshold for the onset of these impacts can reasonably be expected to vary from individual to individual, there exist summary studies that yield consensus type data on degrees of annoyance of environmental noises at various levels, some of which relate specifically to transmission line audible noise6>> <<8.
In an early study, based on actual experience with transmission line operation, Perry cites a probability of receiving complaints as "low (i.e.,
no complaints)" for an audible noise level of 52 '
dBA or less, as measured 100 ft from the centerline of the transmission line; as "moder"te (i.e.,
some complaints)" for similarly measured noise levels of 52.5 to 59 dBA.
These data would tend to indicate a possibility of some potential for annoyance and complaints.
However, this would be for a condition of outdoor exposure at the edoe of the right-of-way and only during periods of precipitation or fog.
This amounts to an estimated 22~ of the total time during a "wet" year (Lehman affidavit, pp.
12 - 13).
Over half of this time (i.e.,
13.1%) is estimated to be during rainfall, when outdoor exposure is likely to be limited and background noise levels to be elevated.
(Lehman affidavit, pp. 12-13).
Using this inclement weather data, and the maximum noise level predicted by Applicants for the edge of the right-of-way (57.1 dBA), an annual average day-night equivalent sound level (LD may be computed as 52.9 7
dBA. If this noise level is taken to be the combined value for the intrusive noise plus background in a rural area (i.e.,
a worst case assumption for fog conditions, and not allowing for masking due to rain-fall noise), this level is seen to be below the LDN value cited by the U.S.
Environmental Protection Agency (EPA)7 of 55 dBA in "residential areas with outside space and farm residences" for the protection of public health and welfare.
This EPA identified level considers both annoyance and speech interference.
A proposed method for assessino the impact of transmission lin audiLle noiseB advocates usino the relationship between intrusive noise levels and annoyance originally developed in transportation noise studies to determine the deqree of annoyance in an area exoo:-e" tc trans~-ission line noise.
The calculated annual average LD~,, for th= Susquehanna transmission lines would under this method be-estimated to result in less than 10': of the exposed people to be "highly annoyed".
In addition, community 1 eact og (base on "q.",et s."urban and rural ar;--.- re-- - fro-,.
~
JG:.
noise sources")
would be expected to range from "no reaction although noise is generally noticeable" to "sporadic complaints".B These comparisons are applicable to outdoor exposures.
For indoor exposure and sleep interference, EPA7 cites a level of 45 dBA as an LDN below which no effects on public health and welfare occur due to interference with speech or other activi ty.
In assessing the potential impact of the Susquehanna plant transmission lines, if one assumed for the sake of argument that a
home is located immediately adjacent to the edge of the right-of-way, indoor noise levels due to the lines themselves would be within the cited EPA values for protection of public health and welfare.
This is due to the reduction in the level of a noise caused by its passage through walls and windows ("transmission loss" ).
EPA estimates an average transmission loss of 15 dB, accounting for partly open windows.
Other researchersg have estimated transmission loss factors ranging from 10-30 dB.
Use of any of these figures results in indoor noise levels within the EPA levels.
Furthermore, tests on 500 kV lines have shown an attenuation of 3 to 4
dB or each doubling of distance away from the line beyond 50 ft from the outside phase.
While I have considered the impact of transmission line audible noise on persons livinq in homes at the immediate edge of the right-of-way, persons in homes located at some distance from the edge of the right-of-way will experience even less noise from this source due to attenuation.
g:
Wt at would be the effect of operation of the Susquehanna transr;.ission lines at a lower voltage of 230 kV with regard to audible noises?
A:
Operational experience has shown 4 that at energized voltages of 343 kV and below, audible noise levels were barely preceptible at ground level within the transmission line right-of-way.
Adverse effects, in terms of activity interference and annoyance due to noise would not be expected.
What effects are likely to result from the audible noise generated by the operation of the transmission lines associated with the Susquehanna Steam Electric Station?
A:
Based on the calculated noise levels of the plant's transmission lines at the planned operating voltage as presented above and on the meteorological data as provided by Applicants, I
conclude that there is a possibility of some annoyance to people in the immediate vicinity of the transmission lines, but only during the time when the conductor surfaces are wet.
I conclude that the potential for speech interference and activity interference is very low, based on comparisons with published EPA cri teria.
Interference with sleep or other indoor activity does not appear likely, based on the EPA criteria.
The potential for the latter impacts are greatly dependent on the distance between the transmission lines and individual dwellings, as well as the existence of acoustic barriers between the lines and the dwellings that may aid in attenuation of noise levels.
Data on the actual distance between transmission lines and individual dwellings and on acoustic barriers are not currently available and so were not considered in this assessment.
In any event, a worst case analysis postulating a
home located at the edge of the right-of-way reveals an annual average day-night equivalent sound level which I would not expect to cause indoor activity interference or annoyance.
I hereby certify that the above statements are true and correct to the best of my knowledge and belief.
John C.
Le Subscribed and sworn to before me this 7th day of January, 1981 No arj Pub ic for
'gomery County, HD MYiCO//MISSION EXPIRES JULYli1%z
References l.
Evaluation of Health and Environmental Effects of Extra Hi h Voltaae EHV Transmission First Interim Report; IIT Research Institute for U.S.
Environmental Protection Agency, Contract No. 68-01-4604, May 1978.
2.
- Bragdon, C. R.,
and R.
K. Hiller, "Comparisons Between Corona Audible Noise and Other Sources";
Proc.
Worksho on Power Line Noise as Related to IEE<<
g i
i p <<
4<<
7.0.P July 17, 1974.
3.
D.
E. Perry, "Corona Noise Measurements in the Field-Methods and Results";
Proc.
Worksho on Power Line Noise as Related to Ps choacoustics; IEEE Power Engineering Society; Report No.
74CH0967-0-PWR; July 17, 1974.
4.
- Comber, M.
G.
and L. E. Zaffanella, "Audible Noise"; Transmission Line Reference Book-345 kV and Above; Electric Power Research Institute, 1975.
5.
Sforzini, M., et al, "Acoustic Noise Caused by A. C. Corona on Conductors:
Results of an Experimental Investigation in the Anechoic Chamber",
IEEE Trans.
Power A
aratus and S stems, Vol. PAS-94, No. 2, March/April 1975.
6.
D. E. Perry, "An Analysis of Transmission Line Audible Noise Levels Based Upon Field and Three-Phase Test Line Measurements",
IEEE Trans.
Power A
aratus and S stems, Vol. PAS-91, May/June 1962.
7.
Information on Levels of Environmental Noise Re visite to Protect Public Health and Welfare with an Ade uate Mar in o Safet
- U.S.
E Pub 550/9-74-004; March 1974.
8.
D.
N. Keast, "Assessing the Impact of Audible Noise from AC Transmission Lines:
A Proposed Method",
IEEE Trans.
Power A
aratus and S stems, Vol.
PAS-99, No. 3, May/June 1980.
9.
Potential Environmental Effects of 765-kV Transmission Lines:
Views Before the New York State Public Service Commission, Cases 26529 and 26559, 1976-1978, U.S. Dept. of Energy Publ.
DOE/EV-0056, November 1979.
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