Air radiation watchfulness: Radiation monitors on the horizon

Written by Susanna Sheehan
 | Wednesday, 16 April 2014 16:54

Duxbury’s own air radiation monitor should be installed at the harbor this spring, state health officials told the Duxbury Nuclear Advisory Committee last week.


The Duxbury Nuclear Advisory Committee hosted the state Department of Public Health at the senior center on April 9 to discuss the Department of Public Health’s radiological air and environmental monitoring programs at Pilgrim Nuclear Power Station in Plymouth.

Suzanne Condon, Assistant Commissioner of DPH and Director of the Bureau of Environmental Health, told the committee that the installation of Duxbury’s first air monitor was “imminent” as the DPH had secured both the monitor and a location on a pole near the harbormaster’s office in Mattakeesett Court.

The $18,000 monitor was approved by residents at last year’s town meeting. An Envinet real-time gamma monitor, it is designed to test for radiation in the air and gather meteorological data, such as wind speed and direction. It is solar powered and will communicate via cellular modem to a base station in Plymouth. Although Duxbury paid for the monitor, it will be installed, operated and maintained by the DPH as part of its wider monitoring system of the air around Pilgrim.

The public health department has 14 real-time monitoring stations near Pilgrim including the three newest ones in other Plymouth locations – one in downtown Plymouth, one at the Colony Place shopping center, (both of which were installed in February), and a third at Gurnet Point, which has been operational since August. All three also gather wind speed and wind direction data, which are important to understanding how radiation travels on air currents.

The Duxbury monitor is being placed “to take sea breeze effects into account,” said Condon.

The data collected from the air monitors are reported to a central computer and monitored daily by DPH staff, said Condon. Emergency pager alerts are sent to senior officials in the event that higher than normal radiation levels are detected.

The radiological and meteorological data will be displayed and analyzed together, Condon said.

“We believe these new monitors will provide a more robust system of watchfulness,” she said.

After a year of gathering data, a summary of the monitors’ information will be available, according to Condon.

Condon also discussed the 2011 annual environmental monitoring report that covers Pilgrim’s emergency planning zone, or EPZ. This is the latest report DPH has compiled of its testing for Pilgrim as well as for the areas around the Seabrook nuclear power plant in New Hampshire and the Vermont Yankee power plant.

This 29-page report is available on the DPH’s Web site under radiation control/ environmental monitoring.

According to Condon, the DPH tests for radiation in samples of food crops, milk, surface water, sediment, fish, and air. Samples are analyzed for radiation by the Massachusetts Environmental Radiation Laboratory (MERL) within the DPH’s radiation control program.

The report states that the data for radiation from 2011 shows levels in the non-existent-to-normal ranges.

“Overall, in 2011, radiation monitoring results for Massachusetts have been either non-detect, naturally occurring (i.e. potassium-40, beryllium-7, and lead-214), at levels expected to be present in the environment from background fallout due to bomb testing in the 1950s and 1960s (i.e. cesium-137), or attributable to a known source or event (i.e. iodine-131 in air samples following Fukushima). No radiation indicators or radionuclides were detected at a level of health concern,” stated the report.

Every year, the DPH and Pilgrim’s owner Entergy collect and test many types of samples in the area around Pilgrim and also from distant locations to analyze them together. For example, seawater is collected monthly from the power plant’s discharge canal by Entergy and the DPH compares these samples to water collected at the Powder Point Bridge, which is outside the 10-mile EPZ.

Fish, lobsters, and mussels are collected twice a year from the discharge canal and are analyzed by the state’s Environmental Radiation Laboratory using gamma spectroscopy. Entergy gets fish, lobsters, and mussels one to two times a year from Cape Cod Bay (considered a distant, or “background” location), which are also analyzed by the state using gamma spectroscopy. For comparison, mussels are gathered twice a year from Green Harbor in Marshfield, which is out of the 10-mile EPZ.

Crops including corn, apples, gourds, gourd leaves, pumpkins, squash, and/or hay forage are also collected by Entergy from a Plymouth county farm once per year and other samples of vegetables and wild vegetation are obtained from several commercial gardens located in Plymouth. Cabbage and strawberries are taken annually from farms in Bridgewater and Duxbury, and hay forage samples are collected in Whitman. All are tested for exposure to radiation.

Cranberries from bogs located within the 10-mile emergency planning zone in Plymouth and in Kingston are tested once a year and samples of cow’s milk are collected monthly from the O’Neil farm in Duxbury. This farm is 11 miles from Pilgrim, just outside the EPZ. It is currently the closest dairy farm where milk samples are available.

Of the items sampled in 2011, only one bluefish had higher than the trace amounts of the radioactive substance, cesium-137, according to the report.

According to the Environmental Protection Agency, cesium-137 is a radioisotope derived from waste produced by nuclear reactors. Its radioisotopes present a health risk if released into the environment and exposure to it can result in an increased risk of cancer.

“Naturally occurring potassium-40, beryllium-7, and lead-214 were detected in nearly all samples…from both within and outside of the (Pilgrim) EPZ,” according to the report, which stated that these three substances occur naturally in the environment in varying amounts.

In the bluefish “cesium-137 was detected at 6.9 picocuries per kilogram (pCi/kg)” from the PNPS discharge canal, according to the report, which further stated that this level is consistent with levels listed “in scientific literature and can be attributed to historical fallout from bomb testing in the 1950s and 1960s.” The level of cesium-137 in the bluefish was under that state lab’s lower limit of detection, which was 6.9 pCi/kg for that sample.

“Importantly, the levels detected do not present health concerns,” stated the report. “Cs-137 was below detection limits in other fish samples from the discharge canal.”

Condon said that there was only one bluefish out of five sampled in 2011 that showed the higher level of cesium-137.

“The wells are closely monitored,” Condon said.

Ground water monitoring reports are also available on the DPH website and are current as of February.

Duxbury Fire Chief Kevin Nord expressed concerns about emergency funding drying up after Pilgrim ceases to operate at some point in the future. Even after the nuclear power plant is shuttered, there will still be radioactive materials in the area.

“If the plant is shut down, the emergency funding stops,” said Nord. “Would it stop for you?”

Condon said that the funding would end for the state although its monitoring program must continue.

“It’s a real issue and a real concern,” she said.