Nuclear Plant Journal, March-April 2016 NuclearPlantJournal.com
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equipment in the containment as well
as a longer outage duration. This
straightforward connection to the steam
generator reduces the risk of injury
associated with equipment handling
and reduces the total radiation exposure
received during equipment installation
and removal in containment. By
implementing these improvements and
by eliminating the need for containment
work, personnel radiation exposure has
been reduced from 10 person-REM for
a typical hard chemical cleaning process
to zero person-REM for the MP3 DMT
application.
The key DMT components and
equipment were consolidated within a
bermed and fenced area approximately
1500 ft from the MP3 blowdown access
room. The location of the process
equipment (see page 52) allowed
access only to authorized personnel and
increased the overall security of the area
where the application chemicals were
located during the application sequence.
The DMT chemical process
eliminates the use of the hazardous
chemical agent, hydrazine, and the
chelant, EDTA. The use of ozone for
waste decomposition has reduced the
need for hydrogen peroxide during waste
process, thus further mitigating potential
risk of hazardous chemical exposure. The
DMT process technology is considered
environmentally-friendly since none
of the chemicals used in the process
solutions are listed in the environmental
hazards table. In contrast with cleaning
processes that utilize hydrazine and
EDTA at high temperatures, DMT
presents no off-gassing hazards. DMT
employs a relatively non-volatile organic
acid at process application temperatures
of <190 °F. In addition, the advanced
waste treatment features integrated into
the DMT process produce no hazardous
liquid waste, significantly reducing
environmental hazards. Thus, the water
resulting from the DMT process may
be released or reused by the plant.
Consequently, this treatment requires
no offsite transportation of liquid waste
material, whereas hard chemical cleaning
would have resulted in well over 35,000
gallons of mixed hazardous waste
requiring offsite processing and disposal.
With over 30,000 man hours worked,
the MP3 DMT setup, application and
waste processing tasks resulted in:
-No reportable injuries -No foreign
material exclusion issues -No rework
-No human performance issues -No
personnel contamination events -No
radiation exposure -Significant reduction
in potential of primary to secondary
leakage due to vibratory degradation
from secondary side flow divergence.
Cost Savings
The cost savings for this project
has three major components. The first is
the >$20M savings over the alternative
hard chemical cleaning process. Next,
the shorter critical path outage duration
resulted in an $8M savings. The final
benefit is that associated with a steam
pressure recovery and its projected
revenue value of $1.5M. This represents
a project benefit of almost $30M.
The cost savings relative to a hard
chemical cleaning application (e.g.,
EPRI/SGOG), are substantial. There is
less equipment, no containment setup
and interconnections, reduced chemical
