Newsletter ENR

TEPCO Crews Try To Cool Damaged Reactors at Fukushima Powerplant

By Pam Radtke Russell

Japanese officials managed to restore electricity to three damaged reactors at Fukushima Daiichi by March 28 but were battling to keep the unit’s radioactive water from leaking into the sea.

Tokyo Electric Power Corp. (TEPCO) reported that water in concrete tunnels beneath Unit 2 was emitting radiation levels of 1,000 millisieverts per hour, or about 100,000 times the reactor’s normal level.

The Japanese government also reported that it had detected the presence of plutonium in the soil around the reactors, a possible indication that a partial meltdown could have occurred at one of the three units.

"The crisis at the Fukushima Daiichi plant has still not been overcome, and it will take some time to stabilize the reactors," said Yukiya Amano, the director general of the International Atomic Energy Agency (IAEA). "The Fukushima crisis has confronted the agency and the international community with a major challenge."

Despite injecting water into the reactors to cool the fuel, TEPCO said water levels have not risen, which could indicate the reactor cores may not be completely sealed off-possibly because of a breach or puncture. The radioactive water could be leaking, according to the utility.

Amano said that, once the situation has been stabilized, the IAEA would like to send an international expert mission to assess the accident. He also called for a "high-level" conference on nuclear safety to take place at IAEA headquarters in Vienna before the summer.

On March 28, the IAEA gave a detailed rundown of the condition of each unit. The agency said the core and fuel integrity at units 1, 2 and 3 were damaged, and damage was suspected to containment in units 2 and 3. Further, there is severe damage to the first, third and fourth buildings. Unit 4 was not operating at the time of the March 11 earthquake and tsunami, but the spent-fuel pool lost water and an explosion occurred.

IAEA said about half the fuel is uncovered inside the first three reactors, but the fuel is stable. Pressure inside the vessel is increasing slightly in unit 1 but is stable in units 2 and 3. Crews were injecting fresh water into all three units’ reactor pressure vessels, though, in unit 2, it was necessary to use a diesel generator to pump the water into the vessel. Firefighters were pumping seawater into the spent-fuel pools through their cooling lines.

The IAEA said temperatures were decreasing slightly, but that unit 1 still had a temperature of 575° F.

David Lochbaum, director of the Union of Concerned Scientists’ nuclear safety project, was scheduled to appear before the Senate Energy and Natural Resources Committee on March 29. Lochbaum said he will propose to the panel that U.S. plants limit the contents of spent-fuel storage pools to fuel that has been removed from the reactor in the past five or six years; everything older than that should go in dry-cask storage, he said.

Fonte: Estadão


At CONEXPO, Pent-Up Demand Brings Solid Turnout

By Tudor Van Hampton

Despite sluggish construction activity, the mood was noticeably upbeat at the largest construction event of the year, the CONEXPO-CON/AGG show, held on March 22-26 in Las Vegas. Nearly 120,000 people showed up for the event, where 2,400 exhibitors displayed equipment, products and services over 2.34 million sq ft.

The turnout was about 17% lower than the previous CONEXPO, in March 2008, which saw more than 144,000 visitors. However, vendors and attendees alike say that pent-up demand for heavy machinery and related products worldwide lifted the atmosphere in Las Vegas.

"The increased global participation by attendees and exhibitors underscores the importance of world markets to our industry," says Megan Tanel, vice president of events for the show manager, the Milwaukee-based Association of Equipment Manufacturers.

International attendance accounted for a record 24% of visitors. On the supply side, Asian manufacturers-such as China-based Sany, Zoomlion, XCMG and Liugong-wowed conventioneers with large booth displays that showed off new machinery ready to go to work in just about any corner of the globe.

Wall Street investors followed the show closely for signs of economic improvement and were particularly interested in the Chinese exhibitors. "Overall, investors were impressed with the aggressive growth strategies presented by each company," says Ann Duignan, an equities analyst with New York City-based J.P. Morgan, in a March 24 research note.

Distribution in developed nations is the highest hurdle for Chinese suppliers, Duignan adds, but these manufacturers offer tremendous economies of scale that threaten to topple established players. For example, XCMG builds about 1,400 cranes a month, while U.S.-based Manitowoc builds 3,000 units per year. Another challenge for these companies is building up a viable, global workforce to sell and support their equipment.

CONEXPO provided a venue not just to showcase new equipment but gave used-equipment sellers significant exposure. Online auctioneer IronPlanet, Pleasanton, Calif., reported more than $22.8 million in sales on a single day, breaking its previous one-day sales record, at its March 17-18 auction. Held before CONEXPO, that two-day auction’s sales totaled $26.7 million, with 14,500 bidders participating from 150 countries.

Vancouver, British Columbia-based Ritchie Bros. sold $58 million in used iron during a two-day, unreserved auction it held on March 24-25 at its brick-and-mortar site in Las Vegas. The location set a new company record for gross auction proceeds in Las Vegas, well exceeding the $48 million off-loaded there around the time of the previous CONEXPO.

Nearly 5,000 bidders from 50 countries participated in the Vegas auction, which offered more than 2,500 lots. International buyers grabbed up $19 million, or 32%, of the available machinery. One of the largest single sales, a 2009 Caterpillar D10 crawler tractor consigned in Las Vegas, went to a buyer in Dubai for $1.25 million.

For more coverage of the show, go

Fonte: Estadão


Spanish Contractor Wins Rail Contract

The Spanish firm Fomento de Construcciones y Contratas SA, ranked 13th on ENR’s list of the top global contractors, has won a $1.72-billion contract in partnership with Algeria’s ETRHB Haddad to build a 66-kilometer rail line in Algeria. The line will connect the city of Tlemcen, the western terminus of the country’s rail network, with the town of Akkid Abbas on the Moroccan border.

The contract was awarded by the Algerian government through the Agence National d’Etudes et Suivi de Realisations des Investissements Ferroviaires, or ANESRIF, an agency created in 2005 to improve the country’s railway system.

The contract calls for the construction of a double-tracked electrified line, a new passenger station in Maghnia and signaling systems. Construction is slated to begin in late 2011 and be completed by 2016. The workforce is expected to peak at 1,000, according to Pedro Gomez, the international business development director for FCC.

This is the second railway contract won by FCC in Algeria, following a $1.3-billion contract awarded last year for a segment connecting Relizane, Tiaret and Tissemsilt in the central region.

Fonte: Estadão


TEPCO Maps Fukushima Shutdown

By Dennis Normile with Pam Radtke Russell

Five weeks into the Fukushima nuclear powerplant crisis, Tokyo Electric Power Co. on April 17 announced a road map leading to a cold shutdown that will minimize radioactive emissions and allow emergency evacuations around the plant to be lifted.
The six- to nine-month plan calls for building new cooling systems as well as enclosures for four damaged reactors while limiting worker exposure to high radiation. "[The work is] very challenging because of the radiation levels," says Jacopo Buongiorno, a nuclear engineer at the Massachusetts Institute of Technology, Cambridge, Mass., who is following the crisis. The nine-month schedule, he believes, "is aggressive but not unreasonable."

The loss of power and backup systems in the March 11 earthquake and tsunami led to partial fuel meltdowns and hydrogen explosions that damaged facilities and released massive amounts of radiation. Tokyo Electric has managed to inject seawater-and later fresh water-into the reactors and spent-fuel pools using improvised approaches, including using a water cannon intended for riot control and concrete pumps. While the company has cooled the fuel and substantially cut radioactive emissions, the emissions continue as contaminated water evaporates or leaks out of the buildings.

Originally, TEPCO hoped to restart the reactors’ cooling systems. However, because of damage, "using the existing cooling systems would be difficult, and the high levels of radiation make it impossible to carry out repair work," says Hidehiko Nishiyama, deputy director of Japan’s Nuclear and Industrial Safety Agency. He says the structure supporting the unit-4 spent-fuel pool, reckoned to be damaged, needs to strengthened. Each bit of construction requires site investigations and detailed design before fabrication and construction can start, Nishiyama says.

Hisashi Ninokata, a nuclear engineer at the Tokyo Institute of Technology, says a system using seawater as the cooling medium might be the first choice, but engineers also are examining natural convection and forced-air heat exchangers.

The challenge is that "workers will inevitably have to access the reactor buildings," says Nishiyama. Robots supplied by iRobot Corp., Bedford, Mass., measured up to 57 millisieverts per hour of radiation in one of the reactor buildings. Japanese regulations normally limit nuclear powerplant workers to 100 millisieverts of exposure per year. Nishiyama says they are considering exchanging and filtering the air inside the buildings and extending a tunnel-like steel shield into the buildings to provide a safe work chamber. To contain airborne radioactivity, they will build around the reactors temporary enclosures of fabric supported by a steel framework.

"There are still a lot of uncertainties," says Ninokata.

Aftershocks still rock the area, threatening existing and new structures. Workers will have to find and close all radioactive leaks. The University of California, Berkeley’s Dana Buntrock, an architect and expert on Japanese construction techniques, says much of this work will be carried out during the summer, with high temperatures exacerbated by the heat emanating from the reactors and workers wrapped in protective gear. "This is not an ideal work environment," she says.

Once the closed-loop heat exchangers and enclosures are in place, crews could begin construction on the structures, likely concrete, required for plant decommissioning and demolition. Nishiyama says one approach being studied is building the structures adjacent to the reactors and then sliding them into place while removing the temporary enclosures. After that, removing the nuclear fuel and demolishing the buildings could take a decade or more.

Fonte: Estadão


Work on Enclosure for Chernobyl Begins

By Peter Reina

While Japan struggles to stabilize its wrecked Fukushima nuclear plant, engineers in Ukraine are only now starting construction of a new enclosure for Chernobyl’s fourth reactor, almost exactly 25 years after it exploded and caused immense human and environmental damage in the region and globally.

It’s too early to say whether the Japanese will need their version of Chernobyl’s $1.4-billion, 29,000-tonne steelwork safe enclosure to clear away their nuclear ruins. But the hard lessons learned in the development of Ukraine’s $2.2-billion shelter implementation plan following the April, 26, 1986, disaster could give Japan’s cleanup a running start.

Chernobyl’s shelter implementation plan should have been completed a few years ago, according to tentative schedules made in the mid-1990s. Now, everybody’s working toward a mid-2015 deadline for the new confinement to be in place.

But judging seemingly sluggish progress by conventional standards makes no sense, says Vince Novak, nuclear safety director at the European Bank for Reconstruction and Development, London, which manages the project’s internationally raised fund.

The combination of nuclear hazards and engineering difficulties puts the Chernobyl project in a class of its own, Novak says. The preliminary early schedule was conditional on findings from subsequent research, he adds, some of which was in previously unknown terrain. "We got to the point where we could understand the scope [only] in the summer of 2003," he says.

"[Even then,] procurement took longer than we anticipated in 2003, and the design of the new safe confinement took longer," adds Novak. "The issues were first-of-a-kind for everybody," he says. The involvement of national and international experts and regulators added further complications.

Finally, the new confinement’s design is on course for securing regulatory approval, probably this autumn, says Eric Schmieman, senior technical adviser with the shelter implementation plan’s project management unit. The unit includes Chernobyl staff and specialists from a consortium including San Francisco-based Bechtel National Inc. and Columbus, Ohio-based Battelle Memorial Institute.

With a span of 257 meters, the 150-m-long arching confinement will rise 105 meters to enclose the entire reactor building. The confinement will have a 100-year design life and accounts for two-thirds of the shelter plan’s budget.

"Most of the preparatory works have been completed," says Schmieman. Putting up a new vent stack over the reactor building next year, removing the old one in 2013 and strengthening walls in the turbine-generator hall next to the new confinement are among major pieces of work still to be done, he adds.

Earthmoving is largely done at the new confinement’s erection site, just west of the reactor building. Piling is under way for the two large ground beams along which the turnkey consortium Novarka will slide into place the pre-assembled confinement. In preparation for the erection of the vault, concrete foundation pads are being cast for cranes.

Novarka late last year awarded the steelwork contract, said to be worth around $60 million, to Italy’s Cimolai S.p.A., Pordenone. With its headquarters outside Chernobyl’s exclusion zone-some 55 kilometers away at Slavutich-Novarka is jointly owned by Paris-based contractors Vinci S.A. and Bouygues S.A. Novarka won its turnkey contract in September 2007.

To protect construction workers from the reactor building’s radiation, which is still intense, the confinement vault will be assembled some 300 meters away. When the foundations are complete, Novarka will backfill the entire 90,000-sq-m erection site with clean fill and a partial cover of concrete slabs to shield ground radiation.

Novarka has devised an arch erection sequence that will minimize the use of labor working at extreme heights. Essentially, the joint venture will assemble the vault in five longitudinal sections joined with hinged connections. Raising the assembly with large tower cranes, the steelwork pre-assemblies will rotate around the hinged joints to form the vault.

Using pre-assembled sections up to 300 tonnes and 25 m tall, Novarka will build the eastern half of the arch, then slide it toward the reactor building. Then, in the erection area, the western half will be assembled and joined to the other half before pushing the whole confinement into place.

When the confinement is fully operational, the unstable parts of the old shelter, which was constructed hurriedly after the disaster, will be among the first tasks for the Ukrainian clean-up crew, says Novak. After that, he adds, "studies suggest that further waste management operations should be deferred for 30 to 40 years to gain some benefits from the [radioactive] decay process."

Fonte: Estadão


Huge Chilean Hydro Project Awaits Environmental Approval

By C.J. Schexnayder

Construction on Chile’s largest hydroelectric initiative, the 2,750-MW HidroAysén project, is awaiting final approval by the country’s environmental agency, which is expected to respond by next month.

HidroAysén-a joint venture between Chilean power utilities Empresa Nacional de Electricidad SA and Colbun SA-submitted its environmental impact assessment on April 15. A decision by the Chilean government on the environmental license for the project is expected in May.

HidroAysén involves construction of five powerplants with an installed capacity of 2,750 MW; the project is located on the Baker and Pascua rivers in the Aysén region of Chile.

Transporting the power from Patagonia to the country’s urban center would require construction of a 2,300-kilometer-long transmission line. Approval of the power lines is expected to be a serious hurdle and much of the environmental opposition to HidroAysén has focused on the transmission component.

Cost estimates for the project are $3.2 billion for the dams and $2 billion for the power lines. If approved, construction is slated to begin by the end of 2014 and be completed within five years.

Fonte: Estadão


Chad To Build Its First Railway

By Shem Oirere

Construction of the first-ever railway line in the oil-producing African nation of Chad is set to start next year. The former French colony signed a $7-billion contract with the China Civil Engineering Construction Corp. in mid-March.

The new, 1,344-kilometer-long railway will link landlocked Chad to its neighbor to the west, Cameroon, and its neighbor to the east, Sudan. The route is expected to facilitate access to the international markets.

CCECC President Yuan Li told reporters in N’Djamena during the signing of the construction deal that the project will be undertaken in two phases.

To be completed in four years, the first phase is slated for commissioning next year. This phase of the railroad will have two lines: one linking the town of Abeche to Adre on the Sudanese border, the other linking the town of Moundou to Koutere near the Cameroon border.

Phase two of the railway project will link these two lines through the country’s capital, N’Djamena.

China has offered to finance the project with a loan signed by the Chad government through the Export/Import Bank of China. However, no agreement has been reached as to how the loan will be repaid.

"We shall soon be discussing the mode of payment. All options remain open, including crude oil, minerals or cash," said Adoum Younousmi, Chad’s infrastructure minister.

Chad’s infrastructure ministry and CCECC, the minister said, are working out the project’s details, including procurement of a design-services contract. Among other issues, the contractor will determine how many tracks the standard-gauge railway line should have. Negotiations are ongoing between Chad and CCECC on the supplier of the rails.

As Chad seeks cheaper means of gaining access to international markets, this new deal is the second attempt to link the country to its neighbors by rail.

In 2001, Libya announced plans to construct a 3,170-km-long line to connect its rail system to those countries to the south, including Chad, Nigeria, Sudan and Niger. The plan did not go forward because, among the countries that would have hosted the line, there was a lack of funding and coordination, Libyan officials later said.

Meanwhile, another plan for a regional railway awaits implementation. Under the New Partnership for Africa’s Development (NEPAD), an African Union program launched in 2001 to boost the continent’s growth, the plan was approved in 2006. The NEPAD railway line will link Chad to Libya and Niger.

Fonte: Estadão

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