OF NEW JERSEY'S ENVIRONMENTAL SURVEILLANCE AND MONITORING PROGRAM
A. THERMOLUMINESCENT DOSIMETERS
Thermoluminescent Dosimeters (TLD) are the primary detectors used to monitor gamma radiation in the environment. A TLD is a passive radiation detector that requires no power source. The TLD contains radiation sensitive phosphors which are designed to have essentially the same sensitivity to radiation as human tissue. They are placed in roughly concentric circles around the perimeter of the reactor and located relative to: (1) major population centers; (2) government buildings; (3) schools and hospitals; and (4) other locations of public interest; (5) locations outside the influence of the reactor (i.e. background locations).
The TLD badge monitors the environment on a continuous cycle 24 hours a day, 7 days a week, thereby providing an integrated exposure dose. They are retrieved and analyzed on a 90 day cycle. Four cycles are summed to provide an annual radiation dose.
C. ENVIRONMENTAL SAMPLING
Criteria used to select the air particulate sampling sites take into account the following conditions: (1) atmospheric stability data; (2) the prevailing wind direction; and (3) the height of the gaseous release point. The air sampling procedures are designed to directly monitor the external radiation pathway to 10 miles from the release point.
High volume air samplers containing chemically treated cartridges and filters allow collection of the iodines (I-131 and I-133) and of air particulates to evaluate the inhalation pathway. The cartridges are collected and exchanged on a bi-weekly schedule. In addition, one air sampler located in the environs of Oyster Creek is sampled on a weekly basis.
Representative water samples are routinely collected and analyzed. They provide a method of evaluating radioactivity that can be ingested by humans and cause internal radiation dose.
Drinking water sampling points (private and commercial well water) within a ten mile radius of the reactor are sampled quarterly. Surface water samples are collected monthly.
Milk samples are collected to determine the type and amount of radioactive materials found in milk. Primarily, radioactivity found in milk comes through the ingestion of water, feed, and pasture land grasses used to feed the dairy herds. Raw milk samples are collected on a monthly basis from four different dairy farms located near Artificial Island. Two gallons of raw milk are collected per sample location. A background location for milk was established in August of 2004 at a dairy farm located in suburban Trenton, New Jersey. This dairy farm is well beyond any influence of New Jersey's nuclear power plants. In addition to raw milk samples, the New Jersey Department of Health purchases various brands of pasteurized milk from local stores and submits these samples to the laboratory for analysis.
Biological samples of clams (Mercenaria mercenaria) and hard-shell crabs are taken semiannually to monitor radionuclide concentrations in shellfish. Edible portions and body fluids are evaluated to determine the radioactive materials being ingested by the shellfish. Edible species of fish are also collected at various locations in the environs of the Salem / Hope Creek nuclear power plant. Samples include a wide variety of species including bluefish, weakfish, and white perch.
Samples of local crops are collected during the growing season (April through October) for gamma isotopic analysis of edible portions. Vegetation samples are used to evaluate the concentration of radioactive materials assimilated by plant life in the environs of the nuclear generating stations. Crops include the edible portions of vegetables such as cabbage, collards, kale, corn, lettuce and tomatoes.
Aquatic sediment samples are collected quarterly from the bottom of water passages that carry effluent from the nuclear generating stations. Sediments are fine solid materials that have settled out of a liquid stream or standing body of water. Accumulation of radionuclides in sediment can lead to exposure of humans through the ingestion of aquatic species (clams, crabs, and bottom-feeding fish) or through direct shoreline exposure.
C. Continuous Radiological Enviromental Surveillance Telemetry
The Continuous Radiological Enviromental Surveillance Telemetry (CREST) system is a direct gamma radiation surveillance and monitoring system. It consists of two networks of envirnmental radiation monitoring instruments, one at Oyster Creek and the other at Artificaial Island. The CREST system is maintained and monitored by the Nuclear Threat Response Section (NTRS) of the BNE.