Single-platform breakthrough for tubesheet machining

Thousands of deep holes can be drilled through a 600mm tubesheet using a standard machining centre, Nuclear AMRC research has shown. The study could lead to significant savings in manufacturing cost and time for a range of heat exchanger tubesheets and support plates.

Typically measuring up to five metres in diameter with over 10,000 deep holes through 600mm of Inconel-clad steel, steam generator tubesheets represent the most demanding application in tubesheet drilling.

With a length-to-diameter ratio of over 30, these holes are challenging for standard drilling techniques, particularly given the number of holes that have to be produced with zero faults. These tubesheets are currently produced on a dedicated gun drilling machine, using a mineral oil lubricant that can present contamination risks to nuclear components, with a long cycle time which can cause bottlenecks.

A new generation of deep drilling tools could remove the need for a dedicated machine. “Lately, there’s been lots of progress in tooling design and materials,” says Miguel Garcia, senior research engineer in the Nuclear AMRC’s machining team. “Now, for the range of hole sizes we’re looking at for tubesheets, it is possible to drill them on a standard machine using soluble coolant.”

drilling test

In a project funded by the Nuclear AMRC research board of member companies, the machining team investigated whether these new drills could meet the demands of tubesheet manufacturers.

The team used the Starrag Heckert HEC1800, a large high-precision horizontal boring machine, to prove a selection of commercially available drills. Each was used to drill 600mm steel testpieces with Inconel end cladding. The researchers observed machine performance, chip formation and tool wear, then measured the accuracy of the holes with a 150mm CMM probe.

Although some of the tested tools could not successfully drill the full depth, the team identified a drill geometry and cutting parameters that produced deep holes of exceptional quality on a standard machine tool platform using off-the-shelf tooling.

Importantly, the holes were produced using a standard soluble coolant, allowing higher material removal rates. By saving minutes per hole, machining time for a full tubesheet can be cut by many days.

tubesheet cu

Single-platform machining of tubesheets will allow manufacturers to reduce costs and become more flexible. The technique could be particularly valuable to smaller businesses which will be able to produce a wide range of heat exchanger tubesheets and other components without investing in new machine tools.

“It adds a lot flexibility to the process, as you can do any other machining operation on the component in a single set-up ā€“ a dedicated machine will only drill,” Garcia notes. “You can reduce the risk of misalignment and the risks of moving the component across the factory, and you’re also reducing the footprint you need from multiple machines.”

Full results have been shared with members. Work continues to optimise the drilling process and reduce cycle time, and to improve robustness to meet industry standards. The team are also working with tool suppliers to test and develop new drill designs.

  • For more news on how the Nuclear AMRC is supporting industry through manufacturing R&D and supplier development, download our Q4 newsletter (4MB pdf).

Nuclear 2016

1 December 2016, London.

The Nuclear Industry Association’s annual conference, Nuclear 2016, will bring together speakers from all parts of the nuclear industry to discuss key developments in 2016 and look ahead to 2017.

NIA Nuclear2016

With keynote speakers and sessions focusing on nuclear new build, decommissioning, small modular reactors (SMRs), export opportunities and more, the conference offers unrivalled access to the sector’s senior leaders ā€“ including Mike Tynan, Nuclear AMRC CEO, who will talk abut the manufacturing challenges and opportunities of SMR development.

For full details and to register, go to: nuclear2016.co.uk

 

 

Nuclear AMRC helping Westinghouse cut SMR costs and lead times

The Nuclear AMRC is continuing to work with Westinghouse Electric Company to reduce build lead times for the US group’s small modular reactor (SMR).

Nuclear AMRC engineers are working with Westinghouse and modular construction specialists from Cammell Laird on a new advanced manufacturing study. The study will explore potential design efficiencies which can reduce costs to customers while promoting growth in manufacturing within the UK.

“The Westinghouse SMR is an innovative, industry-leading technology that builds upon the company’s extensive reactor and fuel technology expertise,” said Jeff Benjamin, Westinghouse senior vice president for new plants and major projects. “The Nuclear AMRC has broad experience in design for the manufacture of large, complex parts for safety-critical applications, and its support will help to increase the efficiency of our design, while building on our specialised UK value proposition.”

Westinghouse SMR with logo

The study follows an initial advanced manufacturing study on the Westinghouse SMR reactor pressure vessel, one of the largest and most demanding parts of any reactor. That study, completed in April 2016, demonstrated that Westinghouse’s design had the potential to be efficiently manufactured in the UK.

The new study will focus on how the SMR design can allow for greater production efficiency through modular assembly techniques.

“Greater R&D focus on technologies surrounding SMR manufacture will reduce the risk, minimise the lead times, while significantly optimising cost and quality delivery performance,” said Mike Tynan, chief executive officer of the Nuclear AMRC. “Design for assembly is one such area of interest which has the potential to significantly reduce construction costs and time, by minimising the amount of labour required on site.”

Heavy engineering group Cammell Laird has also been engaged by Westinghouse to work on the study.

“Cammell Laird has over 40 years’ experience in the design, manufacture, assembly and transport of large complex modules to a number of safety-critical sectors,” said Jonathan Brown, managing director of the Merseyside-based group. “We are pleased to bring this knowledge to support the Nuclear AMRC in undertaking the nuclear module study for Westinghouse.”

Westinghouse says that the study further demonstrates its commitment to partnering with the UK government to deploy the company’s SMR technology, and move the UK from buyer to global provider of the latest nuclear energy technology. Westinghouse also proposes to manufacture fuel for its SMR at its Springfields site in Lancashire.

Nuclear AMRC awarded Athena Swan bronze

The Nuclear AMRC’s commitment to supporting women in engineering and research has been recognised with the Athena Swan bronze award.

The Athena Swan scheme recognises commitment to advancing the careers of women in science, technology, engineering and related fields at universities and research institutions. The bronze award recognises that an institution has a solid foundation for eliminating gender bias and developing an inclusive culture that values all staff.

“Iā€™m absolutely delighted that the people of the Nuclear AMRC have been recognised through the Athena Swan bronze award for their dedication and commitment to providing a working environment that is free from gender bias, recognises the value of the individual, and promotes the unconditional trust and respect needed for true potential to be liberated,” says Mike Tynan, chief executive of the Nuclear AMRC.

“In a business dominated by technology, the Athena Swan bronze award is a prized possession that reminds us that our greatest asset is our people. To build a team that plays a lead role in the creation of a new era of civil nuclear power in the UK requires that talent is unleashed and is unfettered by prejudice and bias. This is the value of Athena Swan ā€“ it is a way of doing business rather than simply an award to be gained.”

Athena Swan team

The Athena Swan application was prepared over the past year by a team from all parts of the Nuclear AMRC, led by technology researcher Dr Kathryn Jackson.

“Equality is good for the nuclear industry, it’s good for the manufacturing research, and it’s good for engineering, which are all areas where women are under-represented and where we’re at the intersection,” Jackson says. “Our remit is to help UK industry win work in civil nuclear, and the nuclear industry has got a higher proportion of men than any other power generation sector, because it’s largely a legacy workforce. If we’re leading in manufacturing research, it makes sense we should be leading the cultural change as well.”

Athena Swan bronze awardThe Nuclear AMRC will now implement the action plan prepared for the application, with the aim of applying for the Athena Swan silver award by 2020. “We’ve highlighted everywhere we’re doing things well where we need to continue, and everywhere we need to do things better,” Jackson says. “There’s a lot of work to do and there’s no shortcutting as we have to demonstrate we have made significant improvements.”

“The bronze award acknowledges that we are on a journey to excellence,” Tynan adds. “My expectation is that Nuclear AMRC will continue to improve the opportunities for gender minorities in the nuclear industry and try to ensure that we access the extraordinary talent that exists in this country to deliver innovative and safe civil nuclear power for generations to come.”