POWER July 2015 - 57

NUCLEAR LIFECYCLE
must be developed and integrated with a subsequent
waste management strategy. Part of
the process includes determining to what extent
remotely operated devices will be used.
Another aspect to consider is whether components
will be removed as single items for
final treatment at a specialized facility or if
they will be decontaminated and/or segmented
onsite.
Incorporating Technology
Improvements
Important progress is being made in the field
of " broad spectrum " initiatives, according to
O'Sullivan. Technology such as 3-D computer-aided
design (CAD), pattern recognition,
wireless communications, and data sharing
via the cloud is being used to improve the
D&D process.
O'Sullivan suggested that 3-D imaging,
using laser technology (or photos and videos),
may soon be translated directly into
CAD systems. He said artificial intelligence
capability could allow machines to recognize
the changing site layout from the simulated
3-D model and then perform automated dismantling
and material handling.
Hitachi-GE Nuclear Energy is using 3-D
plant models in a new decommissioning engineering
platform it created for Japanese
D&D projects to accurately calculate the
amount of material that must be managed as
radioactive waste. Specifically, the system
2. Modeling technology improves the process. Combining i-models with detailed
information about radiation levels in every part of the plant, produces highly visual reports
that support the decommissioning decision-making process. Source: Bentley Systems Inc.
3-D model
Evaluated
radioactivity
Mapping
Calculate
dose rate
Visualize,
retrieve DB
Japan Atomic Energy Agency Phits*
*Particle and Heavy Ion Transport code System
Search dose rate value
Visualize dose rate
Filter by spatial dose rate
Intelligent
3-D DB
Estimate
waste quantity
Visualize waste containers
Display properties
facilities management.
The Hitachi-GE platform determines dose
rates by mapping radioactive sources on 3-D
models of the inside surfaces of equipment
and piping and calculating expected gamma
radiation. The process involves entering dose
rate values on a mesh in MicroStation, colorcoding,
and providing layers of transparency.
The result is a visual representation of dose
rates in three-dimensional spaces. But the
system doesn't just color high-dose areas, it
also offers filtering capabilities by converting
to an i-model and assigning properties
Distancing workers as far as possible
from radiation sources, which is a common
practice at operating plants as well,
can reduce the radiation dose received,
as can using robotics and remote systems
whenever practical.
assesses the radiation dose for workers, the
number of man-hours, and amount of radioactive
waste materials generated from the
demolition, demolition procedure data, and
residual radioactivity.
It uses Hitachi-GE Nuclear Energy's own
CAD system in conjunction with a customization
of Bentley Systems' MicroStation
information modeling software and i-model
technology for the open exchange of infrastructure
information (Figure 2). Bentley's
i-models contain information with engineering
precision, allowing not just graphics to be
shared, but also building information modeling
details that allow such things as the automatic
generation of drawings and reports,
design analysis, schedule simulation, and
July 2015 | POWER
that allow search functionality. With that information,
areas that require caution for safe
entry are easily identifiable.
The system also includes a function for
simulating the cutting of equipment and piping,
and the packing of waste into containers,
using 3-D models. The simulation can calculate
the number of waste containers needed,
contributing to efficient planning.
Improvements in physical and radiological
characterization technology allow a better
understanding of the environmental conditions
prior to human entry into high-radiation
areas. Having a better understanding of the
hazards can help avoid " overprotection " of
workers. When unnecessary personal protective
equipment is prescribed, jobs can take
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longer, resulting in needless radiation exposure,
and it can lead to secondary hazards,
such as heat stress.
According to O'Sullivan, practicing dismantling
activities in virtual environments is
another method that can be used to help minimize
radiation exposure. He said distancing
workers as far as possible from radiation
sources, which is a common practice at operating
plants as well, can reduce the radiation
dose received, as can using robotics and
remote systems whenever practical.
A robotics system developed by Kurion
Inc. offers one example of remotely
controlled equipment being utilized in the
D&D industry. The company successfully
deployed an inspection robot to examine reactor
containment damage at the Fukushima
Daiichi nuclear power plant (NPP). Now it's
developing an advanced robotic arm, called
the Fukushima repair manipulator (FRM), to
repair reactor primary containment leaks at
the plant.
Using cutting-edge robotics technology,
the FRM will allow plant workers access to
the reactor to open holes, clear debris and
obstacles, and plug cracks in the reactor's
vent tubes and torus from the safety of a
remote operating station. Kurion's system
will include a robotic arm outfitted with
advanced cutting, water-jet, and grouting
tools; it also will feature new automatic control
sequences to guide these complex tasks.
The primary objective of the FRM will be to
plug leaks caused by the tsunami that damaged
the plant.
In addition to the robotics solutions, Kurion
has provided two mobile systems employing
ion-specific media to remove radioactive
strontium from water stored in tanks at Fukushima
(Figure 3). The skid-based systems
have removed more than 99.9% of the strontium
from the processed water. Although
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POWER July 2015

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