28th April 2024
C B
Department for Energy Security and Net Zero
3 Whitehall Place, London, SW1A 2AW
Dear C,
Sizewell C Nuclear Power Plant
We are writing to you in your capacity as the responsible officer for overseeing Sizewell C’s Full
Business Case (FBC). We would like to raise several aspects of the project to your attention
which we believe are likely to result in additional costs.
You will be aware that East Suffolk Council (ESC) recently discharged the Sizewell C (SZC) DCO
Requirement 19 (Design of the sea defences) and Requirement 12 (Coastal Processes Monitoring
and Mitigation Plan – ‘CPMMP’) (the “Requirements”), both of which required Sizewell C Ltd (SZL)
to demonstrate that the SZC site can be kept safe from flooding for its full lifetime i.e. until all
spent fuel is removed from the site and all buildings fully decommissioned.
Throughout the DCO planning process, Together Against Sizewell C (TASC), under Interested
Party (IP) ref. 20026424, along with many other IPs, expressed grave concerns regarding the
Applicant’s ability to keep the SZC site safe for its full lifetime. The recent approval of the
discharge of Requirements 19 and 12, have only increased TASC’s concerns.
TASC made numerous submissions to ESC during their consultation period and are currently
engaged in Pre-Application Protocol (PAP) correspondence with East Suffolk Council (ESC)
regarding their decision to approve the discharge of the Requirements. Disclosure obtained from
ESC during pre-action correspondence, alongside the Council’s decision document, has
revealed information that TASC believe will potentially impact the Sizewell C FBC. This is
particularly relevant in light of the huge cost and time overruns experienced at Hinkley Point C
(HPC), some of which resulted from construction activities starting before final designs and
plans were complete.
In light of the disclosure obtained, we would like to draw your attention to the following issues,
which we believe will have an impact on the SZC project’s costs, arising from the discharge of
Requirements 19 and 12,
1. ESC comments (as the lead authority on coastal processes) that the Soft Coast
Defence Feature (SCDF) will require more frequent recharging than SZL suggest.
SZL’s confirmation that they remain liable for the full costs of maintaining the sea
defences throughout the site’s lifetime appear to have provided ESC with some
comfort that it will not be responsible for the costs of maintaining the SZC sea
defences. However, we note that the UK taxpayer, as a significant shareholder in the
SZC project, and/or electricity consumers, will bear such costs under the RAB
financing model.
We refer you to the following:
a) an email dated 01/09/23 (Enclosure 1) from ESC’s Senior Coastal Engineer Paul
Patterson to ESC’s planning department in which he states, “Under the CPMMP SZC
Co has an obligation to maintain a sand / shingle embankment in front of the main site
rock flood defence unless and until the site is decommissioned that can only happen
when all nuclear materials, including waste, is removed from site. To do so will
probably require increasing effort and cost that may exceed SZC Co forecasts,
however, that is a risk for SZC Co. If in the future SZC Co wish to change their
obligations under the CPMMP they can only do so with the approval of ESC and
others. In my view this gives ESC strong protection.”
b) Para 3 on page 2 of SZL’s response in relation to requirement 12 to objectors’
questions (Enclosure 2), “The risk of there being a need for more frequent
interventions than predicted in DCO information to maintain the SCDF over its life
until Cessation, is with SZC Co.”
c) These preliminary comments led to similar references in ESC’s attached decision
document (Enclosure 3), including on page 26, “It is also worth noting that under the
terms of the CPMMP (being discharged under application DC/23/2660/DRR), the
Applicant is obliged to maintain longshore sediment transport at any cost while the
SZC flood defence is in place, unless / until this obligation is amended or removed by
agreement with ESC and the Marine Management Organisation (MMO) in
consultation with other coastal management organisations.” There are numerous
similar other references included in ESC’s documentation.
2. SZL’s applications for the discharge of the Requirements show that:
– SZL has finally admitted that the site will not be clear of spent fuel by 2140, the date
set in the DCO and the date up to which flood risk has been modelled. Extending the
site lifetime by 20 years, from 2140 in the DCO to 2160 makes it more likely that the
SCDF will need further replenishment and makes it more likely that the adaptive
design of the sea defences will need to be constructed by the operator.
– The design of the sea defences has still not been finalised, creating uncertainty to
future costs of construction and maintenance.
– ESC agrees with some of the observations made by Nick Scarr (NS), a contributor to
both the DCO examination and the Requirements’ consultation, who has expressed
major concerns about the lack of truly conservative assessment of the coastal
geomorphology of the Greater Sizewell Bay and the implications this has for the flood-risk to the SZC site, particularly from sea inundation from the west of the site.
3. In para 6.2 on pages 14-15 of ESC’s Design Approval Discharge Consultation
Summary Report (Enclosure 4), Paul Patterson advises, “If we are required to take a
view on the Nuclear Site Safety case in our assessment, then our previous written
submissions in the SoCG and LIR would support NS’s baseline position.”
The above statement follows an earlier comment by ESC on page 8 of the same
document (para no. 7.0): “ESC’s Statement of Common Ground and Local Impact
Report both refer to ESC concern that the approach to assessment of some coastal
process impacts over the site life was not sufficiently precautionary, so we do have a
common overview with NS, albeit the ESC comments include a pathway to resolution
whereas NS believes this to be grounds for the development to be halted.
“The ESC concerns related principally to the risk / impact of HCDF exposure and long
term viability of the SCDF. The SZC Co obligation to implement the CPMMP means
that they must maintain a SCDF and / or take other beach management actions to
sustain a sediment pathway across the SZC site and avoid disruption by an exposed
HCDF. If our concerns are correct the frequency of intervention will be much greater
than forecast. This is a financial and operational risk to SZC Co.
“In the future the effort and cost required to sustain the SCDF may exceed SZC Co
forecasts and lead SZC Co to propose an alternative approach to mitigation of the
negative effect of an exposed HCDF. This may be to withdraw maintenance of the
SCDF, to deepen the HCDF foundation and to maintain Longshore Sediment
Transport by other means (bypassing).”
4. ESC’s decision document (DD) in para 1.4 on page 30, confirms that the adaptive sea
defences would involve the eastern extremity of the sea defences being moved 17
metres, and we know this will take the sea defences outside the Work Zone 1C
parameter set in the DCO. This leads to the risk that either:
a. the sea defences cannot be adapted thereby potentially curtailing the
operational period of SZC; possibly involving a more expensive option to
adapting the sea defences or
b. incurring the major expense of having to remove spent fuel from the site
prematurely to a further temporary storage facility.
The above is acknowledged in an email from Paul Patterson to Stephen Roast (of SZL)
dated 15/08/23 (Enclosure 5)’: “Please confirm that the CPMMP requires SZC to
maintain a SCDF (unless / until that obligation is amended after approval by ESC and
MMO) and that the risk of more frequent management interventions than forecast
being required to achieve this outcome, potentially caused by an extended site life
beyond 2140, or more aggressive shoreline change pressure / storm impacts, lies
with SZC. Please identify existing or add new text within the CPMMP that makes this
obligation explicitly clear.” (our emphasis).
In view of TASC’s concerns about the financial implications for the Sizewell C project arising from
the information above, we would be pleased if you could:
1. Confirm that the SZC FBC will cover costs for maintaining the sea defences for the full
lifetime of the site up to, at least, 2160.2. Advise how many times the replenishment of the SCDF has been assumed to be
necessary during SZC’s financial projections for its full lifetime.
3. Confirm that contingency costs have been calculated in the event that spent fuel needs
to be removed from site prematurely due to impending flooding risks, i.e. a plan B if a
GDF is not available or the spent fuel is deemed non-disposable due to high levels of heat
or high radiation.
4. A risk assessment has been carried out in the event that SZC’s operation needs to be
curtailed early, i.e. before the slated 60 years of operation, due to impending flood risk.
5. Please confirm that the UK government’s stake in the Sizewell C project is/will be
recorded on the government’s OSCAR II software as a stand-alone project.
6. Please advise the level of oversight, if any, that UK Government Investments will have
over the operation of Sizewell C.
7. Assuming Sizewell C is recorded on the OSCAR II system, which organisation will be
responsible for reporting costs to OSCAR II.
Yours sincerely,
Chris Wilson, on behalf of TASC
