ML20069P608
| ML20069P608 | |
| Person / Time | |
|---|---|
| Site: | 05000187 |
| Issue date: | 10/29/1982 |
| From: | Avant D, Cozens G, Woods J NORTHROP CORP. |
| To: | |
| Shared Package | |
| ML20069P605 | List: |
| References | |
| NUDOCS 8212080200 | |
| Download: ML20069P608 (9) | |
Text
e NATURAL ENVIRONMENTAL RADI0 ACTIVITY SURVEY FOR THE PERIOD OF SEPTEMBER 1981 THROUGH AUGUST 1982 l
NORTHROP RESEARCH AND TECHNOLOGY CENTER Prepared by: '
- One Research Park Dan Avant I
Palos Verdes Peninsula, CA. 90274 George Cozens i Telephone (213) 377-4811 Joe Woods I
l 8212080200 821029 i
I E )
' NORTHROP RESEARCH AND TECHNOLOGY CENTER
, INTRODUCTION The health physics environmental sampling program includes a continuous evaluation of the levels of naturally occurring radioactivity in the immediate environs, and out to a radius of five miles from the Northrop Reactor site.
Fluctuations in the radioactivity content of the environmental samples occur from time to time due to seasonal and climatic conditions which may effect the deposition of the atmospheric fallout or other airborne radioactice materials.
These minor variations must be noted since they do add to the natural environmen-tal background; therefore, it is quite important to compile the sample data and periodically compare it with the data from the previous sampling periods in order to establish the trend in the natural background.
The report is a compilation of the data derived from the environmental samples collected and processed during the period of September 1981 through August 1982 which comprises the twenty-first annual r eport.
In order to maintain continuity in the overal) sampling program, the sampling sites have not been changed from those shown in Table I. All sample processing and handling techniques have remained the same as those stated in the preview reports.
AIR ANALYSES A total of 94 continuous air samples were collected during the period from sites S-11 and S-12. The sampling time averaged 180 hours0.00208 days <br />0.05 hours <br />2.97619e-4 weeks <br />6.849e-5 months <br /> per sample. A 72 -
hour decay period was permitted on each sample prior to counting to eliminate natural Radon-Thoron activities.
Figure 1, graphically displays the monthly averages from the two sampling stations. A significant decrease in activity from the previous periods is shown.
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NORTHROP RESEARCH AND TECHNOLOGY CENTER RAINWATER ANALYSES ,
A total of 20 samples were collected from sites S-ll and S-12. The radio-activity content of the rainwater, as shown in Figure 2, shows a decrease in activity from the previous periods.
SOIL ANALYSES A total of 108 soil samples were collected from the sampling sites indicated in Table I. The radioactivity content of the soil samples, as shown in Figure 3, indicates a relatively stable trend.
VEGETATION ANALYSES A total of 108 vegetation samples were collected and processed from the same areas as the soil samples. The samples indicated no increase in radioactivity content. The overall trend was quite typical. The monthly averages are shown in .
Figure 4.
WATER ANALYSES A total of 120 water samples were collected from the sites indicated in Table I. The combined monthly averages for drinking water and pond water are shown in Figure 5. The water samples indicated only a very slight variation in radioactivity.
DISCUSSION Analysis of the data for the overall environmental samples indicates a reasonably stable trend in their radioactivity content, with two significant decreases in activity from previous sampling periods.
At times the radioactivity content of the environmental samples changed due to climatic conditions, the prevailing winds (with the change in seasons), and the temperature inversions in the Los Angeles basin. The smog content in the air during periods of temperature inversions tends to increase the natural background radio-activity of the air.
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- NORTHROP RESEARCH AND TECHNOLOGY CENTER DISCUSSION (Cont'd.)
Since the overall radioactivity content of the environmental samples was reasonably stable, it is apparent that the Northrop Reactor and associated facilities have not contributed significantly to the natural radioactivity background.
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N*0 R T H R 0 P RESEARCH & TECHN0L0GY CENTER TABLE I SAMPLING SITES
.e-SITE LOCATION SAMPLES TAKEN S-1 Reactor Soil, vegetation, and drinking water S-2 Imperial Highway and Soil, vegetation, and drinking water Inglewood Blvd.
S-3 Imperial Highway and Soil, vegetation, and drinking water Sepulveda Blvd.
S-4 Prairie Avenue and Soil, vegetation, and pond water Redondo Beach Blvd. (Alondra park)
S-5 Hawthorne Blvd. and Soil, vegetation, and drinking water Redondo Beach Blvd.
S-6 Hawthorne Blvd. and Soil, vegetation, and drinking water 190th Street S-7 Normandie and Soil, vegetation, and drinking water El Segundo Blvd.
S-8 Rosecrans and Central Soil, vegetation, and drinking water Avenue S-9 Hawthorne Blvd. and Drinking water Century Avenue S-10 La Brea Avenue and Soil, vegetation, and drinking water Slauson Avenue S-ll Atop Engineering Center Air (particulates), and rainwater 900 yards west of reactor S-12 Atop Plant III, 200 yards Air (particulates), and rainwater east of reactor 4 of 4
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