Page 344 - Beyond Decommissioning

320 Beyond Decommissioning

The Site’s Nuclear License requires that the licensee supervise the safety of the tenants
in some circumstances. To facilitate compliance, the licensee has established
tenant safety requirements which are based on its own internal safety requirements
(Neal, 2003).
The latest news at the time of writing (May 2018) is based on Magnox (2016) and
SSG (2017). The Winfrith decommissioning program assumed the reaching an interim
end state (IES, a phrase used in the United Kingdom to mean the end of all physical
works) around 2023. The reference to physical work is important because after the
physical work, natural processes (e.g., radioactive decay and natural degradation of
contaminants) will continue to work toward reaching the site end state (SES). The
original plan was to remove all radioactivity and release the site as publicly open heath
land. The projected use has not changed but the detailed description of the SES and the
plan to deliver it are still under discussion. There could be opportunities to reduce the
amount of physical work now, and leave some residual contamination in situ. This
could also have the benefit of reducing the amount of material that will need to be
imported to the site to bring about the IES. For example, the current view is to leave
behind the basement of SGHWR and DRAGON and backfill with very low-level
(radioactive) waste (VLLW) resulting from the demolition of structures. However,
without the changes in the law, the site will remain a nuclear licensed site (in the
writer’s view, a form of restricted release).

7.10 Harwell Southern Storage Area, United Kingdom

The Harwell Southern Storage Area (SSA) (referred locally as the “Bomb Dump”)
deserves a more detailed analysis. This 7-ha area, contiguous to the Chilton Primary
School, and just 1km off the Harwell (formerly) nuclear research center, was origi-
nally used as a WWII ammunitions storage area by the UK’s Royal Air Force
(RAF) and subsequently for RAW handling and for the burial of chemical, low-level
radioactive and beryllium contaminated waste by Harwell’s nuclear operator,
UKAEA. There are also dwellings and a farm in the vicinity. The SSA consisted
of open ground, small huts, concrete trackways, and several large earth mounds
around the original bomb storage bays. The main hazards were due to waste dumped
in four separate disposal pits. The contamination included hazardous chemicals, a
wide range of radionuclides (plutonium, uranium, strontium, etc.) together with beryl-
lium, which is chemically toxic.
Preliminary decontamination of the SSA was conducted to eliminate the need for
the site to be licensed under the Nuclear Installations Act (as required for the main
Harwell site). However, this remediation was not sufficient to allow unrestricted
access; instead the site remained subject to security. Remediation continued in the
1990s and was completed in 2002. A post-remediation report was drafted to record
all the details of the project. Following extensive site monitoring, the area was land-
scaped and top soiled. Subsequently, the land was approved by the local government
as suitable for recreational or residential purposes. Redevelopment will be undertaken
by a private commercial developer. Given the site vicinity to inhabited areas, public