Advanced Work Packaging (AWP) is the method Owners and EPCs use to turn engineering drawings and models into work a crew can install. AWP for nuclear construction applies the same method to reactor new builds and refurbishments. Planners break the scope into construction, engineering and installation work packages, then sequence those packages along a Path of Construction (PoC). A package goes to a crew only when every constraint on that package is cleared. Nuclear sites leave very little room for unready work, so planning teams use AWP to keep every release predictable from the first package to turnover.
Nuclear projects put two demands on planning: every work package carries hold points, inspections, revision control and records that have to survive turnover, and the same plant scope often repeats across units and sites. EPCs and contractors preparing for the next generation of plants have to plan for both, and many are running AWP on nuclear work for the first time. A plan built well on the first unit can be reused on every unit that follows, so the work package hierarchy, the PoC and constraint management need to be right from the start.
A nuclear program typically runs for a decade or more, and Owners building several units often carry the first unit’s contractors and planning approach through to the last unit. The EPC that wins the first unit's scope sets the plan for every later unit.
A package that reaches the field without its approved procedure, qualified material or scheduled inspector leaves a crew waiting or redoing work. On a reactor site, the lost time costs more than on most industrial projects. Teams new to nuclear scope need a proven way to get ready work to the field without months of trial and error. Research from the Construction Industry Institute (CII) gives AWP a measured track record: projects using AWP decreased total installation cost by up to 10% and increased field productivity by up to 25%.
Field productivity matters even more on nuclear work, where skilled crews are hard to find and every mobilized crew is expensive. AWP protects those crew hours by releasing only packages with every drawing, part and permit in place.
The AWP hierarchy is the same on a reactor as on a refinery. What changes is how tightly each level is tied to outage windows, inspection hold points and licensing commitments. CII's RT-272 implementation model defines the levels.
Planners start by dividing the site into Construction Work Areas and agreeing on the PoC, the order in which areas and plant systems get built or replaced. In a new build, the PoC follows the module setting plan and the civil, mechanical and electrical handoffs inside the nuclear island. In a refurbishment, the outage sequence and the plant systems that must stay available for operating units set the PoC.
Each Construction Work Package (CWP) is a manageable slice of scope within one area and one discipline, sized for one superintendent to own. Engineering and procurement teams then plan their deliverables around CWPs, so construction has a say in the order of design and delivery instead of inheriting a sequence set elsewhere.
Engineering Work Packages bundle the drawings, specifications and calculations a CWP needs, released in the sequence construction requires. Procurement Work Packages bundle the materials a CWP needs in the same sequence. On nuclear projects, both package types also carry the design and qualification documents inspectors check before and after installation. Engineering and procurement release dates matter twice: once for construction and again for inspection.
Installation Work Packages (IWPs) are what crews pick up: one to two weeks of work for a foreman, with drawings, materials, permits, procedures and inspection points included. On nuclear work, the IWP is also where hold points, work instructions and inspection sign-offs come together. An IWP missing a hold point, instruction or sign-off isn't ready and shouldn't be released.
New build and refurbishment use the same hierarchy. The constraints that set the PoC differ: modules and repetition drive new build, while a fixed outage window drives refurbishment.
New build is a long program built around module fabrication, module setting and heavy lifts. Civil, structural and mechanical crews hand areas to each other inside a congested footprint, and the PoC sets the order of those handoffs.
Packages built and proven on the first unit can become the starting point for the next unit, so later units begin from a tested plan instead of a blank one. Reusing the plan only works when planners keep the PoC, packages, constraint checklists and lessons learned in shared AWP software. Lessons left in a closeout report rarely reach the crews on the second unit.
A refurbishment is a long outage with a fixed critical path, worked inside an operating station with radiation protection, confined spaces and tight access. Planners build the PoC backward from the outage milestones (defuel, isolate, remove, replace, inspect, restore), and every IWP has to fit a narrow window.
Constraint management sits at the center of refurbishment planning, since a package that stalls for a missing permit or part can idle a crew with nowhere else to go. Planners need to see weeks ahead which packages have every drawing, part, procedure, permit and inspector lined up.
AWP depends on engineering, scheduling and materials data. Nuclear projects keep the data in the same places as other capital projects: 3D design models, a Primavera P6 schedule, materials management and document control. Planners need AWP software that reads from all of these sources without asking engineers to change how they design.
O3 reads the 3D model directly and builds CWPs and IWPs from model objects. Packages stay linked to the P6 schedule with progress flowing back to P6. O3 integrates with any system seamlessly through out-of-the-box (OOTB) integrations or enterprise REST APIs, from the P6 schedule to document control and materials management. Planners get one view showing whether a package's engineering is issued, its materials are on site and its schedule window still holds, instead of checking readiness by email.
Nuclear design moves through many revisions, and a package is only as good as its drawing revision. O3 gives teams enterprise-grade data management that runs itself. Project data arrives validated and current from the places it already lives, gaps become assigned tasks before they reach the field and teams build from the latest revision every day without anyone cleaning spreadsheets.
A package is ready when nothing stands between the crew and the work. Planners track constraints on every IWP and release only constraint-free packages. On a nuclear site, the constraints to clear before release include:
Readiness tells a team which packages a crew can start. Construction managers and project controls teams still have to decide how many crews to commit, and adding a crew without seeing its effect on the finish date is an expensive guess. What If scenarios in ONBuild, O3's execution software for engineering, procurement and workface planning, show that effect before anyone commits a crew. Teams test extra crews, crew size, productivity and working hours against O3's IWP sequence and compare the projected finish, peak headcount, crew utilization and manhours for each option. Each scenario shows the impact on budget, hours and schedule.
The results show which IWPs moved, and they export as a PDF report a project manager can take to the Owner. The team leaves the weekly lookahead meeting with a staffing plan it can defend with evidence. Our post on What If scenarios for IWP sequencing walks through setting up and comparing options.
Systems completions build on the same IWPs. Each IWP links to the plant systems it completes and to its test and turnover packages, so the turnover record builds as the work happens instead of being reconstructed at the end.
Rules of credit measure progress at the same IWP level. They break each installed component into weighted steps such as set, bolted up, welded, tested and documented, so percent complete reflects completed steps instead of estimates. Rolling component-level progress up to earned value keeps reporting honest and stops the familiar pattern of a project that reads 90% complete for months.
Owners increasingly expect contractors to show an AWP execution plan that explains how the contractor will plan and package the work, and they leave the choice of tool to the bidder. For a nuclear program, the execution plan typically shows how the contractor will:
O3's AWP Software Requirement Matrix sets out what Owners want in AWP software: more than 250 requirements an Owner can use to judge a contractor's AWP plan and tools. Our post on turning AWP expectations into a real bidding standard shows how Owners put the Matrix to work.
Yes. CII treats AWP as a standard best practice proven across industrial construction sectors and project sizes, and the hierarchy applies directly to new build and refurbishment. Teams moving into nuclear work can start with the hierarchy they already use on other industrial projects.
No. The hierarchy stays the same, and the outage schedule sets the PoC. Planners working an outage should expect constraint management to take more of their effort than on new build.
Yes. Planners can carry the first unit's plan into the next unit's project instead of starting over, so each new unit starts with the lessons of earlier units.
You need AWP software that reads the 3D model, the P6 schedule and materials data, tracks constraints at the IWP level and links installation work to completions and turnover. Ask vendors to show those capabilities on your own model and schedule before you commit.
EPCs and Owners choosing AWP software for a nuclear program want to know their software partner will still be there when the last unit turns over. O3’s track record answers that question: 600+ projects and 30,000+ users, with Worley running AWP on O3 as its global standard and Técnicas Reunidas making O3 its corporate standard for AWP projects.
With O3, an EPC builds its AWP execution plan and sample packages in the software that will run the project, so the plan the Owner scores is the plan the team executes. On a multi-unit program, O3 copies the PoC, package breakdown, IWPs, constraint checklists and rules of credit from one project to the next.
Each part of O3 serves a different team on a nuclear program:
IT and security reviewers often sign off before anyone scores features. Each O3 customer runs in its own single-tenant environment with enterprise-grade security, backed by SOC 2 Type II, a SOC 3 report and ISO alignment, with US-only hosting available.
Request a personalized demo to see how your team can plan nuclear work packages in O3, from the 3D model to turnover, and reuse that plan on every unit.