Page 126 - Beyond Decommissioning

Relevant factors for redevelopment 107

farming, residences, etc. The IAEA term for brownfield is “restricted (or conditional)
release” (see Glossary). However, the definition refers only to the radiological char-
acterization of a site after decommissioning. In United States, example of this strategy
is the Pathfinder NPP: the reactor facility is removed and disposed of by licensed
burial, but the slightly contaminated power plant is retained for peaking power as part
of the existing power plant facility onsite. Another example is Fort St. Vrain NPP,
discussed in Section 6.2.1.2.
In NRC guidance “Consolidated Decommissioning Guidance” (NUREG 1757,
September 2006) the NRC set a system of controls designed to maintain protection
at restricted use conditions, including (1) legally enforceable institutional controls that
would limit doses to the critical group to less 0.25mSv/year, (2) engineered barriers as
needed, (3) surveillance and maintenance, (4) independent supervision, (5) adequate
funding, and (6) dose limits to the critical group not greater than 1.0mSv/year in case
institutional controls fail. Regardless of the legal coverage, experience has shown that
restricted release has been difficult to implement for various reasons. For example,
experience has shown that institutional controls can fail. The infamous Love Canal
case is exemplary in this regard (English and Inerfeld, 1999). Same case histories
are described in Greeves and Liebermann (2007). Molycorp Inc. considered initially
a restricted release strategy for their site, which produced an alloy from thorium ore.
Molycorp planned to establish a private corporation to serve as an independent party
for institutional controls lasting for 1000 years: however, the NRC had substantial res-
ervations about that long a durability of a private organization. Eventually Molycorp
gave up the request for restricted release and pursued instead unrestricted release. In
other cases, difficulties were linked to complex dose modeling or public opposition.
A special case is described in Roos and Kollar (2008). The challenge described was to
communicate the exposure risk of radiologically unregulated site development to
landowners, tenants, private contractors, and public works institutions that might
engage in construction activities at or near to the site.
It is noteworthy that some legislations or governmental directives have recognized
restricted release as a preferential option. This is the case of New Hampshire State in
the United States, which passed a Nuclear Decommissioning Law replacing the for-
mer greenfield cleanup requirement with a commercial/industrial site redevelopment
standard. Also included is a clear mandate to provide the local community at Seabrook
NPP with a voice in the post-decommissioning site use (Radwaste Solutions, 2001).
In some decommissioning projects, nuclear facilities may have radiologically con-
taminated/activated areas which are inaccessible to some extent. Or else, the
decommissioning work itself may have made these areas inaccessible as part of the
selected end state. These areas may or may not pose a risk to the next user, depending
on the final planned use of the facility, exposure scenarios, likelihood of access, and
activation or contamination levels. Consequently, restrictions may be placed on the
reuse options for the decommissioned facility. Accessibility to the remaining radio-
activity is only one consideration. The other issue is whether or not any potential
for radiation exposure to the next users is acceptable. If it is deemed acceptable, it
should be justifiable through a formal assessment. Note that this challenge may extend
to subsequent site uses.