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Off-Site Air Radiation Monitoring Systems
Monitors that measure airborne emission of radionuclides from the Pilgrim
NPS include: the Sage System consisting of 14 real-time monitors installed
on the edge of Pilgrim NPS’s property; thermoluminescent docimeters (TLD’s)
placed in 42 locations within 5 miles of Pilgrim NPS; real-time monitors
placed in a few schools for the sole purpose of educating students and not
necessarily adequately monitoring emissions. These systems are part of
Massachusetts Department of Public Health Radiological Control Program.
1. Sage System - Real
Time Off-Site Monitoring System
This system consists of
gamma radiation detectors located at 14 different locations at a one mile
ring (really not a ring, an arc) around the Pilgrim Nuclear Power Station.
These on line detectors transmit radiation levels on a continuous basis by
telephone line to a centralized data logger and computer at the office of
the Radiation Control Program. This began in April 1991.
Deficiencies
The Sage System does not
provide any significant protection to the citizens of Southeastern
Massachusetts. The “NRC Draft Report For Comment On Findings On Issues Of
Offsite Emergency preparedness For the Pilgrim Nuclear Power Station
[NUREG-1438], issued May 1991, expressly noted that MDPH installed this
system, “even though fixed offsite monitors are no longer endorsed by the
NRC...”[ page 2-159].
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Under
the agreement with the licensee, the monitors were installed less than a
quarter of a mile from the plant. Yet, the NRC has found that monitors
closer than 1000 meters [about 2/3 of a mile] would provably provide
inaccurate readings in the event of an accident.
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The
agreement included 22 potential monitoring sites, but only 14 have been
installed. Again this is contrary to NRC research on real time monitoring,
which concluded that using as few as 14 monitors would grossly underestimate
the radiation from narrow emission plumes.
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The
monitors are only in a small quadrant behind the plant. Therefore, there is
no effective monitoring in the directions of Scituate, Marshfield, Duxbury,
Kingston, or much of Plymouth [ including the Gurnet, Saquish neck at the
end of Duxbury barrier Beach}. Granted, the plant is on the coast but there
is no reason why monitors are not placed on Gurnet, and on strategically
placed locations on Duxbury, Kingston, Plymouth shores and interior
locations. Click for
Wind Direction Map.
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There
are no monitors on Cape Cod. The Cape is across open water -- nothing to
break up a plume. The Cape is downwind 3/4 of the year. See accompanying
wind chart. The Cape has statistically significant breast and prostate
cancers which epidemiology studies to date have not been able to completely
explain. Click for Wind Direction Map
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The
placement of the Sage monitors is particularly troublesome in view of the
extensive wind analysis done by the Harvard School of Public Health, under
the direction of Dr. J.D. Spengler and Dr. G.J. Keeler, May 12, 1988. This
study was commissioned by MDPH and is entitled, Feasibility of Exposure
Assessment For the Pilgrim Nuclear Power Plant. The placement of the Sage
monitors effectively ignores the results of this study that MDPH both
commissioned and paid Harvard to conduct. By way of contrast, I would point
out that, at Seabrook station, the Citizens Monitoring Network is installing
monitors on buoys at sea. |
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The Sage
monitors do not measure high and low let alpha and beta radiation – only
gamma. |
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The Sage
System also seems subject to the critical deficiencies outlined by Alfred
Schmidt, engineer/consultant Schmidt Instrument CO., San Carlos, California
in his comments to EPA, March 31, 1992. For example, he states, “ Many of
the off-site air sampling systems are ...deficient because they are housed
in virtually closed metal shelters which seriously restrict the flow of
particle laden air to the collection filters.
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The Sage
System lacks software to make any sense out of the computer data arriving at
MDPH. The data is neither systematically graphed nor charted. There is
just a meaningless pile of numbers in some MDPH office -- doing nobody any
good.
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2. Thermoluminescent Dosimeters (TLD’s)
TLD’s
are placed in 42 locations within 5 miles of Pilgrim NPS to measure gamma
radiation levels. These devices are passive in as much as they must be in
place for a period of time [3 months] and then brought back to the
laboratory to determine the amount of radiation the device received at that
location for that period of time.
Deficiencies
TLD’s
TLD’s
provide only an average figure, and increases of potential significance can
be masked by lower than average readings during other parts of the month.
Biological impact occurs on a daily basis
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TLD’s can
only read to a maximum threshold, that is, like a film badge they can only
read so high. |
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TLD’s do not
read high or low let alpha and beta.
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Dr. Hoffman,
at Penn State, did an analysis of TLD’s and concluded they provided poor
sensitivity to Zenon 133. He said it took about 85 hours at maximum
concentration before anything showed up and that even then the amount was
underestimated by a factor of around 20. |
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The TLD’s
are placed only within 5 miles of Pilgrim NPS. There is no magic shield at
that boundary.
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3.
High School Monitoring Project
This
system consists of radiological and meteorological monitoring systems at
each of 7 high schools [3 in Plymouth; 1 each in Carver, Kingston, Duxbury
and Marshfield]. These on-line monitoring stations are connected by modem
to each other and to MDPH.
Deficiencies:This program
was initiated by the Governor’s Council on Radiation Protection solely as a
teaching device for the students, not as a monitoring device to protect
public health and safety. They recognized that this important job must be
performed by trained personnel and could not be left to janitors, students
or teachers.
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It is overly
optimistic to assume that the schools are all coincidentally placed in the
most favorable locations in regard to population density and meteorological
conditions. |
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The High
School monitors, like the Sage, have poor sensitivity to low energy gamma
and beta. To be protective of public health they should measure gamma, beta
and alpha radiation, at both the high and low energy levels. For example
Iodine-125 is at the 60 KeV and most iodine’s are under 100 KeV.
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Calibration
and testing of equipment is not adequately and consistently performed.
More about Monitoring
pilgrimwatch.org
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