Winfrith Case Study 1 - SGHWR
UKAEA, Winfrith. Site Closure Programme, Front End Engineering Contract
Project Title
SGHWR - Front End Engineering of the Decommissioning.
Work Value
The value of the Front End Engineering was £2.0 Million.
Brief project overview
The Winfrith Steam Generating Heavy Water Reactor (SGHWR) was a prototype powerproducing reactor, which operated between 1968 and 1990. Most of the systems associated
with the operation of the reactor, other than those providing an ongoing safety function, are no
longer operational and the reactor is now in a passive care and maintenance condition.
Decommissioning of the reactor is
being carried out in two sequential
phases. Contract 1 will remove
systems, components and equipment
principally located in the secondary
containment. Contract 2 will address
the primary containment components,
systems and equipment of the
SGHWR. The MWH team provided
support services to UKAEA for the
Front End Engineering studies.
Specific activities undertaken
The first phase of work was to carry out an assessment of options for decommissioning of the
SGHWR using Value Engineering techniques which led to the determination of the best
approach. The team broke the project down to a series of tasks which included:
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Modification to Safety Case documentation
Preparation of a Segmentation report - detailing precisely how the reactor is dismantled
and segmented
Carrying out Changeroom assessments
Carrying out structural and crane assessments of the existing building crane
Preparation of Decontamination and Decommissioning report
Carrying out a Radioactive Waste Estimates Assessment, Waste Categorization
Assessment and Waste Stream Assessments
Preparation of Demolition Assessments and Studies
Carrying out Activation Analysis work on the SGHWR reactor materials to determine
radioactive waste activation levels
Preparation of the Concept Design for the Intermediate Level Waste processing plant
Preparation of a 3D model and animation package to provide a computerised
visualization of the demolition sequence
Preparation of a technical specification and then procuring a nuclear rated Industrial
Robotic Demolition Machine
Preparation of a technical specification for the design and build of a mock up of the
SGHWR reactor to demonstrate segmentation approaches and techniques
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Winfrith Case Study 1 - SGHWR
The next phase of the work was to prepare the concept design package. After preparing the
maintenance strategy and the detailed cost estimate, a detailed programme (using Primavera
P3e planning tool) and an overall assessment of risks to the project were brainstormed and
evaluated. An Operations plan was prepared to evaluate the best shift operating plan to
employ. Discussions were held with UKAEA to recommend a preferred procurement approach.
Timescales for the work
Work on the SGHWR project commenced on appointment of MWH in May 2004 and the last
task order was completed in December 05.
Who the team comprised of
The MWH delivery team was made up of the following members:
 MWH - provision of lead consultant, project management, engineering overview and coordination of the design team
 Studsvik - provision of radiological design and assessments
 INBIS - provision mechanical and electrical designs
 Pell Frishmann - provision of civil and structural designs
 Electrowatt Ekono - provision of nuclear ventilation and containment engineering design
 Nuclear Decommissioning Limited - safety case assessment design
 Gleeds - preparation of cost estimate and cost risk assessment
Success factors
The work resulted in an overall reduction in the projected work of 5 years - reducing the
completion date from 2020 to 2015.
The work has also resulted in reduction in risks, keeping costs within UKAEA's overall budget.
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