Page 132 - Beyond Decommissioning

Relevant factors for redevelopment 113

on a decommissioned site. It should be also noticed that the regulator’s “delicensing”
6
guidance has been updated (Office of Nuclear Regulation, 2016) and the “10 ” value
removed.
In summary, the site redevelopment depends on the restrictions to its use due to any
residual contamination. Restricted use (typically, industrial or commercial) or
unrestricted use (typically, residential or agricultural) affect the selection of remedi-
ation technology and extent of such measures. The selected SES can impose restric-
tions on the form of reuse. For example, the remaining contamination may be stable in
the soil; irrigation, however, may increase the mobility of contaminants.
The restrictions enforced may also vary between different areas of a larger site.
Certain areas of a site may not have received any contamination during a plant’s oper-
ations, and therefore could be redeveloped with no restriction. This point is related to
the strategy of gradual delicensing.
Delicensing of a nuclear site may apply to different parts of the site. At many
nuclear sites there are spaces, typically external to the operations area and
uncontaminated, but owned by the licensee and covered by the nuclear license, which
provide a “buffer” area separating the operations area from publicly accessible area.
At large nuclear sites, the distinction between operations area, controlled area, super-
vised area (see Glossary under area), and uncategorized area (moving from the site
center outwards) is useful to this end. For example, the supervised area can be another
name for buffer area. The waste zoning concept applied by French authorities to
nuclear decommissioning may also cast light on the progressive delicensing approach
(ANDRA, 2013; Borrmann, 2010): the a priori defined nonnuclear zones can be
redeveloped first. It can be useful to redevelop buffer areas soon after the nuclear facil-
ity has ceased operation or after most of the radioactive inventory (typically, the spent
fuel) has been removed. Timely redevelopment of buffer areas can set the whole site
redevelopment in motion and help fund the decommissioning of the nuclear (i.e., con-
taminated) part of the site.
Another benefit from the progressive delicensing and redevelopment of parts of the
site is financial. The costs of many decommissioning activities and the associated
maintenance and surveillance are related to the licensed part of the site. By gradually
delicensing parts of the site, the size of the remaining site is decreased and the running
costs are also decreased. Moreover, by enclosing decommissioning activities within a
smaller boundary, the risk of recontaminating clean areas is also reduced. However,
owing to limited human activities, robust flora and fauna habitats may have developed
within buffer areas. This condition may impose reuse restrictions, which are based on
non-radiological (e.g., ecological) factors.
The notion of delicensing parts of a nuclear site can also usefully apply to buildings
and areas (administration buildings, visitors’ centers, cafeteria, stores of spare parts,
parking lots, etc.) that are less relevant to the core business of the site. These facilities
tend to be located in peripheral parts of the site and usually have never been contam-
inated during plant operation. If kept in good structural condition, these facilities are
fit for reuse; in fact, they can be the starting point for site decommissioning,
delicensing, and redevelopment without interfering with the central structure.