The Coast Star |
Clean-up team removes radioactive material from pool
By Marcella DeSimone
The current
remediation project at the Camp Evans site, a 250-acre Army facility in
Wall Township, is the removal of cobalt 60, a radioactive element, from
the aluminum-sided pool where it is currently stored.
In additition to preparing to remove the cobalt safely stored
in the pool, the remediation team has done a survey of the area outside
checking for cobalt 60 in the soil. There was a cobalt spill in the
1950s which was cleaned up then and again in 1980, according to increasingly
strict contemporary standards.
According to Dave Craig, program manager for IceSolv Inc., from
Hershey, Pa., the contractor hired by the government to perform the remediation
process, the current survey concludes that there are levels of cobalt at
the site; however, the levels are so low, they do not pose a public health
and safety threat. Surveys of the entire area have gone to the U.S.
Nuclear Regulatory Commission (NRC) for approval.
The Evans Area of Fort Monmouth has been used by the Army to
support the research and development of communications and electronic equipment,
since the beginning of World War II. Use of the radioactive materials
supporting the mission began in 1950 and continues today. The NRC
regulates the use of radioactive materials through licenses issued to users.
Scientists working at the site in the late 1950s and early 1960s
needed a radioactive source for testing and research, so they created cobalt
60.
To make cobalt 60, the scientists bombarded rods of cobalt 59,
a naturally occuring isotope which is non-radioactive, with neutrons which
attach to the cobalt 59. The neutrons then transform to cobalt 60,
a hazardous, radioactive material.
The cobalt 60 was housed in an aluminum-sided pool to shield
the researchers from its radiation. According to Mr. Craig, the source,
cobalt 60, has been in the area for 20 years.
Cobalt 60 has a 5.27 year half life, meaning that its radioactivity
loses energy every 5.27 years, Mr. Craig said.
When the facility was new, the light given off by the rods was
strong enough to read a newspaper by. The cobalt stored in the pool
has “now gotten to the level that it’s not of adquate strength for a research
tool, but still would present a hazard to individuals,” Mr. Craig said.
Because the level of cobalt found via the survey are in such
low concentrations, it would not be economically feasible to take remediation
action, he said.
“The NRC recognizes that once you get certain isotopes into the
soil, there is a level below which they genuinely don’t pose a hazard to
public safety. The traces they found the cobalt 60 in are 10 times
lower than the NRC’s release limit,” Mr. Craig said.
The NRC, which has been following and checking the remediation
process all along, requires a specific license for cobalt 60, which stipulates
that it must be stored under 20 feet of water in order to shield people
working with it.
To that end, the cobalt has been placed in aluminum rods and
stored in an aluminum-sided pool filled with 20 feet of water.
The rods had been in an aluminum matrix. Now hat the rods
are old, the aluminum had to be broken free of the cobalt. The team
accomplished that, then cleaned the pool, placed the cobalt in containers
and out them in the bottom of the pool.
The next step is to place the containers of the rods in shields
which are 12 inches thick with lead and steal siding. This shield
will bring the rods out and protect everyone in close proximity from the
radiation instead of the water.
The cobalt will then be transported by truck, in accordance with
all applicable Department of Transportation guidelines, to be buried at
a site that has been in operation for 40 years in Barnwell, S.C.
The sources in the pool will be removed next week. Once
the sources ate gone, the team will check for residual contamination; the
water will go through a filter basin, then mixed resin beds. When
it is found safe, it will be released into the sewerage system, Mr. Craig
said.
The results of the remediation team’s cobalt testing of the site
is currently being reviewed for approval by the NRC.
According to Base Transistion Coordinator Mike Ruane, the entire
Evzns area has been surveyed by the remediation team. The surveys
have all been sent to the NRC for analysis and release. The surveys
of about 100 or 100 acres of the site have already been approved by the
NRC; the remediation team is awaiting approval of the surveys of the remaining
90 acreas.
“We anticipate approval from the NRC on the 90 acres in May of
June,” Mr. Ruane said.
Photo caption above:
All in a day’s work. Rob Jacobs [top left] looks
into a pool where rods of cobalt 60, a radioactive material, are stored.
Mike Barrett [bottom] scans the floor for radioactivity. Although
conditions ate perfectly safe, people who work at Camp Evans often joke
about “glowing” once they leave work. [Mike Jones photo]
Page updated December 30, 2003
page created September 23, 2000
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