complete list from the beginning because the volume of waste and variety of waste
types is large and certain radionuclides contained in the wastes are difficult to
identify and measure. Therefore, stepwise development and evaluation are important. A management system of the waste inventory should be established, and new
waste information obtained by several intensive waste characterization projects
should be added to the management system, where the information will be shared
among concerned organizations.
The management system should include information about treatment method
and source term characteristics, including waste form, volume, surface dose rate, ID
number, and location of waste package, which are collected when raw wastes
are treated. This system should be maintained and used until final disposal of
the wastes. When all wastes are disposed of in a designated disposal facility, the
inventory list will be used as the waste records of the disposal facility.
28.3 Development Strategy of Waste Treatment, Storage,
Transport, and Disposal Technologies
The authors proposed a work flow for selecting a waste management technology [2]
(as shown in Fig. 28.1). Establishment of the development criteria for each technology is a fundamental issue and the first step of the development.
For treatment technology, it is important to have a simple system that can be
applied to a variety of wastes, and which has a volume reduction factor and is
economical. In addition, the system must minimize secondary waste and address the
difficulty of residual research and development (R&D) to commercialize the technology. Regarding the stability of waste forms produced by any treatment technology, a
low leaching rate is required, especially for waste containing long-lived radionuclides
over a certain amount. Easy identification and measurement of the radionuclides in the
waste by the treatment process would also be considered an advantage.
Storage technology has many options that are either in operation or under R&D
in different countries. The storage cost is an important index to use when selecting
an option. If a waste generates a large quantity of heat as a result of containing a
large amount of beta- and gamma-emitting nuclides such as Cs-137, the waste
storage period should be considered before final disposal to reduce heat generation.
If the waste has greater heat generation in disposal, the waste emplacement area
must be increased to reduce the temperature of the surrounding engineered barriers
or rock to less than the allowable temperature. As a consequence, disposal cost will
increase. The storage period and disposal cost have a strong mutual relationship. If
the storage period must be increased by more than a few hundred years to reduce
heat generation for disposal, certain radionuclides such as Cs-137, whose half-life is
less than several decades, would have undergone significant decay by time of
disposal, which also raises the possibility of lowering the waste classification
level for disposal.
28 Consideration of Treatment and Disposal of Secondary Wastes Generated. . .
323
types is large and certain radionuclides contained in the wastes are difficult to
identify and measure. Therefore, stepwise development and evaluation are important. A management system of the waste inventory should be established, and new
waste information obtained by several intensive waste characterization projects
should be added to the management system, where the information will be shared
among concerned organizations.
The management system should include information about treatment method
and source term characteristics, including waste form, volume, surface dose rate, ID
number, and location of waste package, which are collected when raw wastes
are treated. This system should be maintained and used until final disposal of
the wastes. When all wastes are disposed of in a designated disposal facility, the
inventory list will be used as the waste records of the disposal facility.
28.3 Development Strategy of Waste Treatment, Storage,
Transport, and Disposal Technologies
The authors proposed a work flow for selecting a waste management technology [2]
(as shown in Fig. 28.1). Establishment of the development criteria for each technology is a fundamental issue and the first step of the development.
For treatment technology, it is important to have a simple system that can be
applied to a variety of wastes, and which has a volume reduction factor and is
economical. In addition, the system must minimize secondary waste and address the
difficulty of residual research and development (R&D) to commercialize the technology. Regarding the stability of waste forms produced by any treatment technology, a
low leaching rate is required, especially for waste containing long-lived radionuclides
over a certain amount. Easy identification and measurement of the radionuclides in the
waste by the treatment process would also be considered an advantage.
Storage technology has many options that are either in operation or under R&D
in different countries. The storage cost is an important index to use when selecting
an option. If a waste generates a large quantity of heat as a result of containing a
large amount of beta- and gamma-emitting nuclides such as Cs-137, the waste
storage period should be considered before final disposal to reduce heat generation.
If the waste has greater heat generation in disposal, the waste emplacement area
must be increased to reduce the temperature of the surrounding engineered barriers
or rock to less than the allowable temperature. As a consequence, disposal cost will
increase. The storage period and disposal cost have a strong mutual relationship. If
the storage period must be increased by more than a few hundred years to reduce
heat generation for disposal, certain radionuclides such as Cs-137, whose half-life is
less than several decades, would have undergone significant decay by time of
disposal, which also raises the possibility of lowering the waste classification
level for disposal.
28 Consideration of Treatment and Disposal of Secondary Wastes Generated. . .
323