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Universe›Priority accounts›Nuclear Decommissioning Authority
Non-departmental public body · DESNZ · 17,000+ across NDA group

Nuclear Decommissioning Authority

Atos has been the NDA-group IT incumbent since 2012 through the £140m Shared Services Alliance covering 18k users, 30 locations and 19 service towers across four site-licence companies. Sellafield's IAMS successor via CCS TS4 RM6190. £76.1m Application Management + £48.23m Hosted Infrastructure, envelope up to £107.69m through 2034. is scheduled for competition late May 2026 with contract award 19 April 2027. Plus a £33m SAP S/4HANA migration and c.£90m adjacent services for 118 apps. This is the biggest single re-let in the NDA group's IT history.

Situation · account brief

Defend the 14-year incumbency. Re-win IAMS in 2026.

Headline figures

Sellafield IAMS successor envelopeTwo lots via CCS TS4 RM6190 through 2032, extendable to 2034.
£107.69m
Original NDA Shared Services AllianceWon 2012. Extended October 2020. Still active per The Stack, January 2025.
£140m
SAP S/4HANA migrationLive technical dependency for the IAMS bid. April 2026.
£33m
Applications in scopeOn-prem apps in the IAMS pipeline notice, including SAP and Microsoft Azure workloads.
~118

Why this account moves now

  • 30 Sep 2025 (updated 2 Mar 2026). Sellafield IAMS re-competition pipeline notice published under CCS TS4 RM6190 Lots 4 & 5. £48.23m Hosted Infrastructure + £41.51m Application Management ex VAT. Competition anticipated late May 2026. Contract awarded 19 April 2027, running through April 2032, extendable to 2034.
  • 8 Jan 2025. The Stack reports Atos/Eviden 'continues to work with Sellafield' as long-term technology and security services provider. public confirmation of continued incumbency 12+ months into the re-competition window.
  • 19 Nov 2025. ONR eases Sellafield cyber attention level from 'significantly enhanced' to 'enhanced'. new CISO appointment credited as reinforcing strategic direction. Managed cyber services, SOC modernisation, CAF-aligned assurance remain a bounded, urgent buy.
  • Apr 2026. £33m SAP S/4HANA migration is a live technical dependency for the IAMS bid. Any bidder without a credible SAP S/4HANA-on-Azure landing pattern is disqualified in practice.
Timeline · dated events

Every dated event in evidence, oldest first.

  1. 2 October 2024
    ONR fines Sellafield £332,500 for cyber security shortfalls.
    Period 2019-2023. Three offences including missed OT/IT annual health checks. District Judge Goldspring ruled 'medium culpability (high end)'. onr.org.uk
  2. 25 November 2024
    Nicola O'Keeffe appointed Sellafield CFO.
    Board turnover follows the cyber prosecution and precedes Hutton's permanent CEO appointment. Sellafield ARA 2024-25
  3. 8 January 2025
    The Stack confirms Atos/Eviden 'continues to work with Sellafield'.
    Following Sellafield's £2.6m Darktrace 2-year renewal. thestack.technology
  4. 20 March 2025
    PAC oral evidence. Decommissioning Sellafield.
    Hutton (Sellafield), Peattie (NDA), Bowyer (NDA CFO), Maxwell (DESNZ), McDonough (DESNZ) gave evidence for the PAC 28th Report. committees.parliament.uk
  5. 4 June 2025
    PAC 28th Report. 'Sellafield's race against time'.
    £136bn lifetime cost could rise if delays continue. Treasury Minutes response CP 1382 followed. committees.parliament.uk
  6. 30 September 2025 (updated 2 March 2026)
    Sellafield IAMS pipeline notice. up to £107.69m through 2034.
    CCS TS4 RM6190 Lots 4 & 5. Competition late May 2026. Contract 19 Apr 2027. Runs to April 2032, extendable to 2034. find-tender.service.gov.uk
  7. 13 October 2025
    £2.9bn Non-Nuclear Infrastructure contracts awarded.
    Morgan Sindall / Costain / HOCHTIEF, 9-year (+6) arrangement through 2040. gov.uk
  8. 19 November 2025
    ONR eases Sellafield cyber attention level to 'enhanced'.
    New CISO appointment credited. Enhanced is still not routine. onr.org.uk
People · named decision-makers

Named, dated, with prior-role evidence where available.

CDIO · Sellafield
Graeme Slater
CDIO, Sellafield Ltd (from 2021)
Prior: Managing Director, Grays IT Limited (technology divestment / transformation consultancy). 20+ years IT leadership.
Owns cyber resilience and data. IAMS-shaped tender authored under his direction. Named accountable owner for the SAP + hosting programme.
gov.uk
CDIO · NDA HQ
John Seglias
CDIO, Nuclear Decommissioning Authority (NDA HQ)
Prior: Long-standing NDA-group CDIO responsibility across the SSA covering 18k users, 30 locations, 19 service towers.
NDA-side accountable owner of the SSA relationship with Atos since 2012. Owns the group-level view of IAMS successor.
thestack.technology
CISO · Sellafield
David M (from Jan 2024)
Chief Information Security Officer, Sellafield Ltd
Prior: Home Office (Head of Cyber Security Operations); Foreign Office (CISO). Whitehall CNI cyber patterns.
SOC modernisation, OT/IT convergence, CAF-aligned assurance framing. Named as reinforcing strategic direction in ONR's 19 Nov 2025 update.
thestack.technology
CEO · Sellafield
Euan Hutton
CEO, Sellafield Ltd (permanent from 1 Nov 2024)
Prior: 'No evidence of Sellafield's IT networks having been targeted by groups linked to foreign governments' (BBC, 18 Dec 2023). personal public defence of cyber posture.
Personally invested in the cyber-defence narrative. He owns the outcome of the IAMS re-let.
gov.uk
CEO · NDA
David Peattie
CEO, Nuclear Decommissioning Authority
Prior: Named alongside Sellafield leadership at PAC oral evidence 20 Mar 2025. No publicly evidenced technology-supplier pattern in this pass.
committees.parliament.uk
CFO · NDA
Kate Bowyer
CFO, Nuclear Decommissioning Authority
Prior: Named at PAC oral evidence 20 Mar 2025. No publicly evidenced supplier pattern.
committees.parliament.uk
CFO · Sellafield
Nicola O'Keeffe
CFO, Sellafield Ltd (from 25 Nov 2024)
New CFO in the year the IAMS tender lands. Value-for-money case is her first big procurement decision on record.
Sellafield ARA 2024-25
Contracts & money · dated positions

Every named contract with a value and expiry where public.

WorkstreamIncumbentDetailExpiryStatus
NDA-group IT (Shared Services Alliance)Atos£140m from 2012 covering 18k users, 30 locations, 19 service towers across four NDA site-licence companies. Extended Oct 2020 into 2022. Still active per The Stack Jan 2025.Through IAMS re-competitionIncumbent since 2012
ICT Hosted Infrastructure Management (Lot 1)Successor competition Q2 2026£48.23m ex VAT via CCS TS4 RM6190 Lot 4 or 5. Contract from ~Apr 2027.Competition May 2026; contract 19 Apr 2027Re-competing now
ICT Application Management (Lot 2)Successor competition Q2 2026£41.51m ex VAT, ~118 apps incl. SAP + Microsoft Azure. Contract from ~Apr 2027.Competition May 2026; contract 19 Apr 2027Re-competing now
Cyber threat detectionDarktrace£2.6m 2-year renewal signed 12 weeks after Oct 2024 ONR fine. 10 days professional services/year.Jan 2027Live
PPP Lot 1. IntegrationKBR20-year Programme and Project Partners framework (2019, £7bn+).2039Live
PPP Lot 2. Design & EngineeringJacobs20-year framework. Wood on £770m 20-year design & engineering partnership since 2019.2039Live
PPP Lot 3. Civil ConstructionMorgan Sindall InfrastructureAlso lead of £2.9bn non-nuclear infrastructure (Oct 2025).2039 + 2040Live
DNWP framework £4.6bn (Oct 2025)Amentum, AtkinsRéalis, Westinghouse ES UK, Altrad, Cavendish Nuclear, Shepley Engineers15-year high-hazard risk-reduction framework across 4 lots.2040Live
Government signals · parliament, regulators, ministerial

Named forum, named speaker, dated.

20 March 2025
Public Accounts Committee. oral evidence
PAC oral evidence. Decommissioning Sellafield.
Euan Hutton (CEO Sellafield), David Peattie (CEO NDA), Kate Bowyer (CFO NDA), Clive Maxwell (2nd Perm Sec DESNZ), Lee McDonough (DG Net Zero DESNZ) gave evidence for the PAC 28th Report 2024-25.
committees.parliament.uk
4 June 2025
PAC 28th Report 2024-25 (HC 363)
'Sellafield's race against time'. clean-up not going quickly enough.
£136bn lifetime cost could rise if delays continue. Ministerial pressure for delivery-management tooling. Treasury Minutes response CP 1382 published.
committees.parliament.uk
16 December 2024
Energy Security and Net Zero Committee
ESNZ Committee session with NDA-group CEOs.
CEOs of NDA, Nuclear Waste Services and Sellafield Ltd (Hutton). Cross-Whitehall commissioning of nuclear-industry delivery tooling and reporting.
hansardsociety.org.uk
2 October 2024
ONR statement / Westminster Magistrates Court
Sellafield fined £332,500 for cyber security shortfalls.
District Judge Goldspring. 'medium culpability (high end)'. ONR thematic interventions clarifying expectations around IT/OT convergence followed.
theguardian.com
Sources · full evidence index

Every claim on this account is footnoted here.

  1. Find a Tender 018199-2026. Sellafield IAMS pipeline notice
  2. Find a Tender 060974-2025. Sellafield ICT hosting/apps
  3. The Stack. Sellafield Darktrace licences (Jan 2025)
  4. ONR. Sellafield fined £332,500
  5. ONR. Sellafield cyber attention level eased (Nov 2025)
  6. Data Center Dynamics. SAP S/4HANA + hosting
  7. GOV.UK. £2.9bn non-nuclear infrastructure
  8. GOV.UK. £4.6bn DNWP framework
  9. GOV.UK. Hutton permanent CEO
  10. PAC oral evidence. 20 March 2025
  11. PAC 28th Report 2024-25
  12. Sellafield Annual Report & Accounts 2024-25
  13. Atos press release. Sellafield extension 2020
  14. NEC Contract. Sellafield PPP framework
  15. GOV.UK. Graeme Slater