ML20235B399
| ML20235B399 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 09/17/1987 |
| From: | Dignan T PUBLIC SERVICE CO. OF NEW HAMPSHIRE, ROPES & GRAY |
| To: | Edles G, Rosenthal A, Wilber H Atomic Safety and Licensing Board Panel |
| References | |
| CON-#387-4433 OL, NUDOCS 8709240089 | |
| Download: ML20235B399 (7) | |
Text
ropes & GRAY 22S FRANKLIN STREET h
BOSTON, M MASSACHUSETTS O2110 3
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IN PRoviOENCE 87 SEP 21 P 4 :0 3 '" *^5"'"o'o" 30 RENNEDY PLAZA -
TELEX NUMBER 940519 ROPGRALOR BSN 8001 TWENTY SECONO STRFET, N W.
PROVIDENCE, R L 02903 TELEX NVMBER 9 51973RO*CSGRAfS$N W A S H I N GTO N. D. C. 2 O O 3 7 (401) 521-6400 T g L EroplE R S.
(617) 423-2377 (617) 423-7848 i.f ;
(202) 429-1600 TELECOPIER;(408) 5210980 INT E R N ATIO N AL (6171423-6905 LLL' TELECOPIER:(202) 429 '529 September 17, 1987 Alan S.
Rosenthal, Esq., Chairman Atomic Safety and Licensing Appeal Board l
U.S. Nuclear Regulatory Commission i
Washington, D.C.
20555 l
Howard A. Wilber Atomic Safety and Licensing Appeal Board U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Gary J.
Edles, Esq.
Atomic Safety and Licensing Appeal Board U.S.
Nuclear Regulatory Commission Washington, D.C.
20555 Re:
Public Service Company of New Hampshire, et al.
(Seabrook Station, Units 1 and 2), Docket 50-443, 50-444 Offsite Emergency Planning ~O b Your Honors:
We enclose herewith a copy of the Applicant report of the August test of the Merrimac sirens, as directed by this Board in its Memorandum and Order of July 30, 1987.
Very truly yours, p-A Thomas G.
Dignan, Jr.
TGD/cp Enclosure cc: Service Listw/ encl.
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September 4,1987 J/N 39292 Mr. Travis N. Beard General Office Building New Hampshire Yankee Division of Public Service of New Hampshire Route 1, Lafayette Road Seabrook, NH 03874
Reference:
Ambient Noise Measurements in Merrimac, Massachusetts -
Dear Mr. Beard:
Attached is a report describing the referenced ambient noise study conducted in Merrimac, Massachusetts, for the New Hampshire Yankee Division of Public Service of New Hampshire. Wyle Laboratories has participated in the design or evaluation of prompt notification systems at 18 nuclear generating plants. The Merrimac measurements were conducted in accordance with procedures employed in evaluating the siren alerting systems at many of these plants and routinely used by Wyle for the analysis of community noise measurements.
Please contact me if you require further information concerning this noise survey.
Very truly yours, WYLE LABORATORIES Wyle Research ff y.
c<
j ohn R. Stearns J
Manager, El Segundo Operations Attachment WYLE RESEARCH 128 Marytand Street, El Segundo. Cal.fornia 90245 213 322-1763 213 678 4251 TWX 910 348 6699 CaDie WYLAB
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l l
l ATTACHMENT l
Ambient Noise Survey Conducted in Merrimac, Massachusetts 1.0 Introduction Wyle Laboratories conducted measurements of the ambient noise environ-ment at nine locations in Merrimac, Massachusetts, on August 19 and 20,1987.
The purpose of this survey was to establish the daytime' ambient noise level for siren alerting at nine locations in accordance with the FEMA criteria of a 10 dB differential between the ambient noise level and the siren level.
At the measurement locations in the survey, siren levels were estimated to be between 50 dB(C) and 60 dB(C). As shown in this attachment, the measured ambient levels all meet the 10 dB differential requirement.
2.0 Measurement Equipment The Merrimac ambient noise measurements were obtained using instrumen-tation with a precision equivalent to that obtained with a Type 1 Sound Level Meter complying with ANSI Standard S1.4. The following equipment was employed for the measurements:
Nagra IV S3 Tape Recorder B&K 4165 Microphone & Nagra Preamplifier B&K 4230 Acoustic Calibrator Windscreens, Tripod, Sling Psychrometer The recorded data were subsequently analyzed with:
B&K Instruments Model No. 3347 One-Thed Octave Band Analyzer Digital Acoustics 6078 Cornmunity Noise Analyzer 3.0 Measurement Locations Measurement locations identified in T.able I were selected to obtain addi-tional data at sites utilized in two previous surveys:
Locations 1 through 6 were included in the survey by HMM Associates o
conducted on March 10, 1987, and described in the HMM letter of March 11,1987, to Public Service of New Hampshire. These sites were selected because design coverage levels in the northeast section of town are predicted to be between 50 and 60 dB(C). To provide M
1 LA80RATORit$
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acceptable siren coverage, the daytime ambient noise levels in these areas must be at least 10 dB below the design coverage levels of the sirens.
o Location 2 and Locations 7 through 9 are sites where measurements were taken by Mr. Brion Koning on February 11, 1987, for the Massachusetts Attorney General.
This survey was described in Mr. Koning's affidavit of February 12,1987.
4.0 Data Acquisition Following site selection, the microphone and preamplifier were mounted on a 4-f t stand and connected to the Nagra tape recorder. The tape recorder was activated and the 15-minute ambient noise sample was recorded. A calibration of the system was performed at the beginning of each new tape and, if appropriate, immediately prior to measurement. The set-up, measurement, and disassembly procedure generally took about 30 minutes. During this period, weather measure-ments were taken and observations of identifiable noise sources were entered on the log.
5.0 Data Analysis Data analysis was conducted to determine if the predicted siren levels exceeded the outdoor daytime ambient levels recorded at the measurement locations by 10 dB. FEMA-43 specifies that the ambient noise level should be measured in the one-third octave band containing the predominant siren tone. The ambient background noise level is traditionally defined as the level exceeded 90 percent of the time (L90), i.e., the residual noise level in the absence of steady state or frequently recurring single noises.
Data analysis consisted of playing the data tapes through the B&K 3347 One-Third Octave Band Analyzer into the Dighal Acoustics Community Noise Analyzer. The B&K analyzer was set to pass only the 630 Hz one-third octave band. The Digital Acoustics unit calculated and printed the L90. The 630 Hz one-third octave band frequency limits are 562 Hz to 707 Hz which includes the predominant siren tone of 680 Hz.
This procedure for met.suring the differential between the siren level and the ambient noise level is based on the signal detection theory for detection of WYLE LASOAATOmits 2
m_.__.____ _ _ _ _ _ _ _ _
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pure tones in a random noise background. This concept states that only random noise frequencies within a certain (critical) bandwidth are effective in masking a pure tone at the bandwidth center frequency.
In the frequency range above 400 Hz, this critical band may be approximated by a one-third octave band. Thus, noise energy outside this one-third octave band does not appreciably mask any pure tone signal that lies within this band.
6.0 Data Results The results of the survey are depicted in Table 1 - Ambient Noise Levels Measured in Merrimac, Massachusetts. It is noted that at all sites (except for Location 3), the ambient in the 630 Hz band are below 40 dB and therefore meet the FEMA-4310 dB criteria for alerting with 50 dB(C) siren levels is satisfied. At Location 4, the level is 41 dB; however, this site is within the 60 dB(C) siren coverage and therefore also meets the FEMA criteria. Table 2 provides a summary of identifiable sources and a description of the area.
WYLE LABORATO8HES 3
I.
1
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l Table !
Ambient Noise Levels Measured in Merrimac, Massachusetts i
L90 630 Hz One-Third Octave Band 1
- Location Date*
Time **
(dB) j 1.
Bear Hill Rd., Northeast of Farm 8/19 1320 21 2.
Just North of 64 Bear Hill Rd.
8/19-1359 23 3.
High St. & High St.
8/19 1504 41 4.
High St. & South Pleasant St.
8/20 1115 38 5.
River Rd. & Locust St.
8/20 1155 35 6.
River Rd. & Merrimac St.
8/20 1325 36
{
7.
21 Pleasant St.
8/20 1445 38 l
8.
Merrimac St. at Merrimac/Haverhill Town Line 8/20 1530 34 9.
4 River Rd.
8/20 1230 33 1
- Weather conditions were as follows:
Measurements taken on 8/19 Wind: 0 to 6 mph; average temperature: 77 F.
l Measurements taken on 8/20 - Wind: 0 to 8 mph; average temperature: 82 F.
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All measurements were of 15 minutes duration.
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1 Table 2 Identifiable Sources l
Location Noise Sources Area Description 1, 2 Moderate traffic, approximately 50 cars /
Rural, widely-spaced br; 6 heavy trucks /hr; occasional light homes & farms i
aircraf t; birds & insects 1
3 Nearby freeway noise, light traffic on Suburban residential, High St.; approximately 25 cars /hr; moderately-spaced l
birds & insects single family homes 1
4 Nearby traffic (Broad St. & River Rd.),
Suburban residential, light traffic on High St., approximately moderately-spaced 25 cars /hr; birds & insects single family homes 5, 6 Moderate to heavy traffic, approximately Suburban residential, 175 cars /hr; 5 heavy trucks /hr; occasional moderately-spaced light aircraf t; birds & insects single family homes 7
Nearby traffic (Broad St. & River Rd.),
Suburban residential, light traffic on High St., approximately moderately-spaced 10 cars /hr; birds & insects single family homes 8
Light to moderate traffic, approximately Suburban residential, 40 cars /hr; distant freeway noise; moderately-spaced occasional light aircraf t; birds & insects single family homes 9
Moderate to heavy traffic, approximately Suburban residential, 175 cars /hr; 5 heavy trucks /hr; occasional moderately-spaced light aircraf t; birds & insects; occasional single family homes boat on river WYLE
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