At the start of May, Japan closed its last working nuclear reactor. Last year, in the immediate aftermath of the Fukushima Daiichi accident, Germany announced it was abandoning all future plans for new nuclear power plants. That could be taken as a sign that the nuclear power industry is on its last legs.

However, for many countries, nuclear power is still an attractive option. At the start of the year, 30 developing nations met at an IAEA workshop in Vienna. All are still committed to developing nuclear power generating capacity, the IAEA says. According to the IAEA, Belarus, Bangladesh and Vietnam have all signed agreements recently with Russia to begin nuclear power programmes.

One of the most important markets for new nuclear plant construction remains China. US-based nuclear plant crane builder Westinghouse PaR Nuclear recently signed a deal with Taiyuan Heavy Machinery Group to form a joint venture to produce crane components and fuel handling equipment in China.

Polar giants
The new company, to be called PaR-TZ Nuclear Company, of which PaR Nuclear will hold a majority interest, will provide the assembly, testing and sale of new critical crane components and fuel-handling equipment, as well as the associated services and spare parts of these to the Chinese commercial nuclear market.

The new company will be based in Taiyuan, China, located approximately 500 km (311 miles) southwest of Beijing. "China has a fast-growing economy and a dramatic need for more electricity generation," said Jack Allen, president, Westinghouse Asia. "Clean, safe, reliable nuclear power will be an important source of that electricity, and this arrangement enables us to provide close-to-the-customer solutions and support for crane component and fuel-handling equipment needs."

From 2000 to 2010, China’s energy demand doubled and in 2011, its electricity consumption rose 11.7%. Currently, China has 15 nuclear power plants in operation, more than 25 under construction and more about to start construction. By 2020, the country expects to increase its nuclear capacity to 70 to 80 GWe. "There is a large, nuclear-specific market for crane components, fuel-handling equipment, spare parts, and outage and installation services in China," says Bill Burns, president, PaR Nuclear. "We are pleased to be joining with TYHM to broaden our collective reach and further enhance our ability to provide equipment and services to the Chinese nuclear market."

PaR Nuclear has a significant and ongoing engagement in the Chinese nuclear market.

In 2009, the company formed a joint venture company with Hutchinson Manufacturing to fabricate, assemble and test large cranes for nuclear power plants, including the Westinghouse AP1000 nuclear power plant.

That company, called NuCrane Manufacturing, shipped the first AP1000 polar crane from its factory in Hutchinson, Minn., to the flagship AP1000 nuclear plant, Sanmen Unit 1, in August 2011.

Westinghouse built the NuCrane plant in Hutchinson, Minnesota, specifically to manufacture the ancillary crane equipment for AP1000 nuclear power plants. Warren Baumbarger came out of retirement in 2009 to manage the plant when it opened.

He explains how the polar crane will be used in containment on a circular track above the reactor. "It’s used to help build the plant initially and then its purpose is to lift the reactor head when they do service. It will also be used to help replace the steam generator, which is replaced every 10 to 12 years."

The hoist and trolley have a 300USt capacity, and the girders have an 800USt capacity — specifically for the steam generator lift. "This crane was actually designed to lift up a steam generator and set it on the girders to get it out of there," Baumbarger says. "It’s a very lengthy process and this crane was designed to shorten that up. It’s thousands of dollars an hour when a nuclear plant is shut down."

It’s a very tight space where the polar crane is located, he explains. There is a clearance of about 12-14in between the crane and the reactor vessel’s domed ceiling.

"They try to use all the space they can. The new AP1000 plant has a much smaller footprint than all the power plants built 20 to 30 years ago," he says.

While the primary function of the crane is to lift off the reactor head, it does have an auxiliary hoist of 25USt for small maintenance inside the reactor vessel.

NuCrane started building the polar crane in April 2010, welding together plate steel for the girders. The crane has a 37.2m span and the trolley gage is approximately 8.4m. The girders are in three pieces, weighing 122USt in total.

With the crane’s location above the reactor head, engineers had to consider radiation exposure, and consulted design specifications from the United States Nuclear Regulatory Commission. One major concern is seismic activity, and the crane goes through a seismic inspection. "They actually build the crane on a computer model and run it through a seismic event, and you can see the crane jumping around and moving. It has seismic restraints on the trolley and bridge, so if the crane is jumping up and down because of an earthquake, it can’t come off," Baumbarger says.

Westinghouse also designed a function to allow the crane to take two-block without any damage should there be a catastrophic failure with the limit switches.

All of the polar cranes for the AP1000 will be made to the same specifications no matter where the plant is being built — unlike existing plants, Baumbarger points out, for which each crane is designed and there is no commonality among parts.

In addition, PaR Nuclear will provide refuelling equipment for the three additional AP1000 plants currently under construction in China: one at Sanmen in Zhejiang Province and two at Haiyang in the Shandong Province. The flagship AP1000 unit, Sanmen 1, is expected to come online in 2013.

Small but tough
It’s not just builders of giant cranes who are finding work from the nuclear power sector though. In the UK, Lift Turn Move were commissioned to design a specialised electric chain hoist for the Sellafield plant. Project manager James Porter worked closely with the engineering department of Sellafield to develop a hoist specific to their unique requirements, and the plant’s harsh envrionment.

The chain hoists will be used for maintenance operations within a cell/cave that contains a nitric acid atmosphere. In accordance with safety procedures, this area is inaccessible by engineers due to the extremely high levels of radiation and acidic gasses, so the operators can only carry out operations behind a 1.5m thick concrete wall with viewing through lead glass windows and in-cell cameras.

As a result of these very stringent safety measures, the hoist needs to be extremely reliable and suitable for purpose as changing the hoist or even performing an unscheduled minor repair would be a mammoth, time consuming and expensive operation.

Regular maintenance of the hoist is made possible by way of bionic arms which detach the hoist from the lifting beam and transfer it to a maintenance room where personnel in full radioactive protective clothing can carry out the required inspections and maintenance.

The GIS hoist that was used for this project was a standard GCH model hoist, with extensive modifications developed from scratch by LTM in conjunction with the mechanical and electrical engineers at Sellafield.

The standard GIS GCH hoist has many features which made it the ideal choice for this application; the simple contactor control, the aluminium body and covers and the lack of electrical printed circuit boards are crucial elements to the suitability of this hoist. Crucially, the hoist also has a number of stainless steel components and the external coating on the hoist is resistant to harsh environments, which David Southern of Sellafield remarks "is what initially sold the hoist to us when searching."

Sellafield also provided Porter with a list of components that work well in these harsh environments and the R&D department of LTM designed a bespoke solution to include these components. This entailed fitting special stainless steel internal and external limit switches and designing both mechanical and electrical external upper limits which will send signals back to the external control board to show the operator the height of the load hook. Room was made within the hoist for these additional components by removing the internal control and electrical components, the end result being a hoist that is perfectly suited for the nuclear industry.

James Porter comments, "This project was exciting and extremely interesting; the guys at Sellafield were a pleasure to work with. There were so many angles that had to be covered and knowing that we covered everything and have developed a hoist that suits the harsh environment such as the nuclear industry gives me enormous job satisfaction."

Closing down
New plants and plant upgrades have been one source of work for the lifting industry. But even where nuclear plants are coming to the end of their lives, specialised lifting equipment is still needed. At the world-renowned Hanford nuclear site in Washington, USA, a 3USt overhead crane has been installed to help handle high-level radioactive waste containers at a new waste treatment facility. The crane, supplied by American Crane and Equipment Corporation (ACECO), will be used for handling the 208 litre steel drums used to contain residual solid waste before and after treatment.

It was fitted as part of main contractor Bechtel’s work building the US Department of Energy’s (DOE) new US$12.2bn Hanford Tank Waste Treatment and Immobilization Plant, which will treat 254 litres of radioactive and chemical waste stored at the installation. As the crane will be used for critical applications in the High Level Waste Vitrification Facility’s drum cleaning, monitoring and maintenance areas, it is required to have several safety features for operation on a nuclear installation.

One of these is the facility for its remote operation from a local operator interface point located in a room adjacent to the drum handling tunnel.

The ACECO project manager who oversaw its installation, Troy A Wetzel, explained, "Due to accessibility limitations caused by high levels of radiation in the hot cell, the crane is equipped with onboard systems that allow for remote recovery in the event of a credible single random or common mode failure.

"The highly integrated and specialised crane is designed with remote recovery features including redundant hoist drive train components, providing lowering and raising of the rated load, a redundant bridge drive that provides recovery capability with the full rated load, additional retrieval capability of crane if the redundant bridge drive fails and redundant electrical circuits that guard against electrical common mode failures.

Installation of the 3USt bridge crane at the High Level Waste Vitrification Facility had to proceed quickly to allow construction work on the upper floors of the building to continue to schedule. Weighing in at 6USt, the crane had to be installed using a 55USt Potain MD 1400 special application tower crane to lift it over the 17m-high facility walls and carefully place it on rails 4.8m above ground level, despite just inches of clearance at either end of the 5m long crane.

Bechtel’s Suzanne Heaston explains:"The clearance from the end of the bridge to the wall was the minimum for the building tolerances.

"The only way to fit this crane into the building is by rigging it in ‘over the top’. Rigging the crane over the top and setting it on rails took just a day. That said, the installation is not complete. The crane at this point is only staged and not yet operational, but in order for work to commence on the upper stories of the building the crane has to be first installed before the floor above it and the pipes above it can be placed."

Construction work on the High Level Waste Facility is well underway.

When completed in 2016, material from the Hanford facility’s underground waste storage tanks will be pre-treated to separate highly radioactive waste, typically the solid fraction, from the low-activity liquid waste material. The high-activity waste will then be processed at the vitrification facility and blended with glass-forming materials, before it is superheated to 1,149°C.

It will then be stored in its inert glass form inside stainless steel containers and transported for storage elsewhere on site. Commissioning of the DOE’s Hanford Tank Waste Treatment and Immobilization Plant is expected by 2019, with full operational capacity to be achieved within the following three years.