cranes at chernobyl - robotic automation · pdf filethe day concluded with a presentation from...

SHOW REVIEWLifting and riggingequipment in thespotlight at PLASA 2012,staged at London's EarlsCourt

INTERVIEWSpain-based materialhandling specialist andweighing systemsprovider Airpes hasadapted in the wake ofrecession

SHOW PREVIEWNow in its eighth year,LiftEx 2012 takes place29-30 November at theRicoh Arena, Coventry, UK

AERIAL WORKPLATFORMSA German-made compacttracked lift was used formaintenance work at aunique facility in New York

ISSUE NUMBER 6 • SEPTEMBER/OCTOBER 2012

LIFT & HOISTINTERNATIONAL

CRANES ATCHERNOBYL

liftandhoist.com

EVERY ISSUE: Overhead Cranes and Hoists • Access Platforms • Lift Trucks • Controls and Components

WORK CONTINUESIN THE AFTERMATHOF THE NUCLEARPOWER PLANTDISASTER OF 1986

5LIFT AND HOIST INTERNATIONAL • LIFTANDHOIST.COM

LHI welcomes special report from one of the mostfascinating overhead crane projects in the world.

Five years ago I chaired an overhead cranebreakout session at a conference in London.The day concluded with a presentation fromEric Schmieman, who, at the time, was safetymanager at the Chernobyl containment project,

where overhead cranes would work in the aftermath ofthe shocking, devastating Chernobyl accident thatoccurred on April 26, 1986, destroying Unit 4 at thenuclear power plant.

Conference delegates listened as Schmiemanexplained how cranes would work in thedeconstruction and safe disposal of the accidentconsequences in a New Safe Confinement (NSC) on thesite of the most catastrophic disaster in the history ofcommercial nuclear power.

I was hooked on the project and have kept in touchwith Schmieman—he works at the global research anddevelopment organisation, Battelle MemorialInstitute—ever since. I am delighted that we canpublish in this issue a special report from Chernobyl bySchmieman, corresponding author VijayParameswaran, of Bechtel International Systems, Inc.,and their colleagues.

An international tender was initiated in 2004 fordesign and construction of the NSC. A subcontract forthe design and manufacture of the main crane systemwas awarded to US-based PaR Systems, Inc.

One of many fascinating dimensions of the projectis the mobile tool platform, which is connected to the

crane carriage. The tool platform is a custom-made tensile truss thatwill serve as a stable platform for remotely operated tools. A robotic armis attached to a rotating mounting plate to allow work to be performedin a complete hemisphere. Remotely operated high radiation cameraswill provide full coverage of the Chernobyl plant and all operationsduring the next phase of the project as workers are located remotely andwill perform nearly all operations using cameras.

The authors believe that this is the largest implementation of atensile truss design for these purposes—and I certainly can't contestthat. Because it is first of a kind, the manufacturer constructed a 25percent scale prototype in the US, which is this issue's cover image.Read more about the project from page 18.

CONFERENCEDELEGATES HEARDHOW CRANESWOULD WORK INTHEDECONSTRUCTIONAND SAFE DISPOSALOF THE CHERNOBYLACCIDENTCONSEQUENCES IN ANEW SAFECONFINEMENT

EDITOR’S LETTER

RICHARD HOWES, EDITOR

HOOKED

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INTERNATIONALLIFT & HOIST

SEPTEMBER/OCTOBER 2012ISSUE 6

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SPECIAL REPORT - CRANES AT CHERNOBYL

18 LIFT AND HOIST INTERNATIONAL • LIFTANDHOIST.COM

BACKGROUND

The Chernobyl nuclear power plant(ChNPP) accident that occurred on April26, 1986 destroyed Unit 4. After the

accident situation was stabilised, it becameapparent that sequestration of the damagedreactor was necessary to minimise long termradiological impact on personnel and theenvironment. A temporary confinementbuilding, the Object Shelter (OS), wasdesigned and constructed between May andNovember 1986.

The primary purpose of the ObjectShelter was to prevent further spreading ofthe radioactive dust and debris. It was builtunder extremely difficult and hazardousconditions and was intended to last 30 years.Upon completion of construction, thebuilding had more than 1,000 sq m ofopenings that allowed some dust to escapeand water to enter the steel structure.

Although some measures have beentaken in the past 26 years to stabilise thestructure and reduce corrosion, the risk ofcollapse of the Object Shelter continues toincrease over time. Its confinement functionneeds to be performed by a new structure,

and the Object Shelter needs to be dismantledin an orderly manner.

The structural elements beingdismantled will be large and heavy. Nuclearfuel material and other radioactive waste willbe placed in heavy shielded containers. Thedismantling activities and handling of heavyshielded waste disposal casks will requirelarge and sophisticated cranes that are thesubject of this paper.

In 1997 the G-7 nations prepared theShelter Implementation Plan (SIP) for theconversion of the OS into an ecologically safesystem. The SIP consists of 22 tasks, thelargest of which is the design andconstruction of a New Safe Confinement(NSC).

The NSC will be constructed adjacent tothe OS to minimise radiation doses to

construction workers, then slid over the OSon a runway system using hydraulic power.The NSC is an enormous arch-shaped steelstructure which will protect the OS from theelements, confine any radioactive dustreleases, and support a massive and uniquecrane system. The approximate dimensions ofthe NSC arch are 250m wide, 150m long, and100m tall. A section of the NSC is illustrated inFigure 1.

A donor community, consisting of 46countries and organisations, support thework of the SIP. Funds are administered bythe European Bank for Reconstruction andDevelopment (EBRD). The facility owner isState Specialised Enterprise ChernobylNuclear Power Plant (ChNPP). Oversight ofSIP work is provided by a ProjectManagement Unit (PMU) staffed by

MASSIVE AND UNIQUEThe design and manufacture of the main cranes system was integral to the New Safe Confinementproject at Chernobyl, the scene of a nuclear power plant disaster in April 1986.

THE AUTHORSN. A. (Vijay) Parameswaran, corresponding author, Bechtel International Systems, Inc.(USA); Igor Chornyy, State Specialised Enterprise Chernobyl Nuclear Power Plant(Ukraine); François de Saint Victor, Bouygues Travaux Publics (France); Dan Kedrowskiand Rob Owen, both PaR Systems, Inc. (USA); Eric Schmieman, Battelle MemorialInstitute (USA).

Figure 1: New Safe Confinement section looking East



representatives of ChNPP and a consortium ofBechtel International Systems Incorporated(Bechtel) and Battelle Memorial Institute(Battelle).

An international tender was initiated in2004 for design and construction of the NSC.The contract was awarded in 2007 toNOVARKA, a joint venture between VinciConstruction Grands Projets and BouyguesTravaux Publics. NOVARKA subsequentlyawarded a subcontract for design andmanufacture of the Main Cranes System(MCS) to PaR Systems, Inc.(Minneapolis/Saint Paul, Minnesota, USA).

The MCS is installed just below the NSCceiling, approximately 80m (275ft) aboveground level. The MCS will be installed in twolarge lift operations inside the NSC byNOVARKA under technical supervisionprovided by PaR. The MCS will be installedand tested in the non-radioactive assemblyarea before arch sliding.

The following presents someengineering details and unique features ofthe MCS:

PAR SCOPE OF WORK• Two 96m (315ft) bridges (approximately

7m [25ft] wide) • Six runways, top running, under

hung design • One classic carriage hoist

• Single hoist configuration; 50tonnes capacity

• One secure carriage hoist• Dual hoist configuration; 40 tonnes

capacity (personnel)/50 tonnescapacity (materials)

• May be utilised to transfermaintenance personnel throughoutthe facility in a shielded protectivebox

• One mobile tool platform carriage (MTP)• Quantity of six hoists operating

simultaneously to hoist and lower aplatform with a tool arm on theunderside

• Lower platform attachments suchas hydraulic power unit, vacuumsystem, arm/tooling supplied byothers

• Runway rails and conductor bars• Control system and camera system• On site erection supervision

Figures 2 and 3 provide an appreciationof the extraordinary size of the MCScomponents. To demonstrate scale, a Boeing777 is illustrated parked below the bridgesand in front of the NSC.

BRIEF DESCRIPTION AND FUNCTIONS OFEACH MAJOR MCS COMPONENT: CRANE BRIDGESTwo crane bridges are top-runningunderhung, suspended from crane railsoriented East-West and located at an

elevation of 76m inside the NSC. Due to theirconsiderable length (96m), each bridgemoves on six crane rails. Each girder has fiveindividual pinned spans to provide theflexibility to maintain wheel contact fordifferent load cases and arch movement. Thebridges are designed such that two fullyloaded carriages may be on the same bridgewith a separation of at least 22m centre-tocentre. The control cabinets are located onthe bridge with wireless communication tothe control room. Although local control fromthese panels is possible, the cranes arenormally operated from a control roomlocated in a building separate from the NSC.The crane bridges are also equipped withaccess ways for maintenance of the bridges.

CLASSIC CARRIAGEThe classic carriage is a top running trolleywith one drum. It has four driven wheels andfour idler wheels to support garage transferactivities. The carriage wheelbase is 6.5m(21ft) by 7.0m (23ft). Carriage travel speed is 0to 15 m/min. Lifting capacity is 50 tonnes.Lifting speed: 0 to 10 m/min. Vertical liftingdistance of 73m (240 ft). Continuous hookrotation at 0.25 RPM. Carriage controls arelocated on the trolley with wirelesscommunication to the control room.

SECURE CARRIAGEThe secure carriage is a top running trolleywith two drums. It has four driven wheelsand four idler wheels to support garage

transfer activities. The carriage wheelbaseis 6.5m (21ft) by 7.0m (23ft). Carriage travelspeed is 0 to 15 m/min. Lifting capacity is50 tonnes (materials) or 40 tonnes capacity(personnel). Lifting speed: 0 to 10 m/min.Main hoist vertical lifting distance of 71.2m(234ft). Recovery hoist lifting up 10m (33ft),down 15m (49ft). Continuous hook rotationat 0.25 RPM. Carriage controls are locatedon the trolley with wireless communicationto the control room.

In order to allow worker access to highradiation areas of the Object Shelter, the

Figure 2: NSCcompared toBoeing 777, samescale

Figure 3: MCSbridges comparedto Boeing 777,same scale

Secure carriage

Classic carriage



NSC is equipped with a shielded protectivebox. Workers can be transported in theshielded protective box only by the MCSsecure carriage. The secure carriage can beused in cooperation with the classiccarriage to lift beams with a length >50mand weight of up to 100 tonnes.

CARRIAGE EQUIPPED WITH MOBILE TOOLPLATFORM (MTP)The MTP is a custom-made tensile truss thatwill serve as a stable platform for remotelyoperated tools. The MTP is composed of twotriangular shaped platforms, upper andlower, connected by six wire ropes. The sixhoists on the upper platform allow raisingand lowering of the lower platform to thework area. The hoists also precisely controltension on each wire rope so that the lowerplatform can sustain significant horizontalloads and torque generated by the use ofthe tools. The MTP design is much morethan the standard anti-sway technologyused in the crane industry—it is an invertedStewart Platform and has the sameproperties as a rigid structural element.

The rigid platform provides an idealdelivery system for remote tooling that willbe required in the Chernobyl dismantlingefforts in the future. For the Chernobylapplication, a robotic arm is attached to arotating mounting plate to allow work to beperformed in a complete hemisphere belowthe MTP. Remotely operated high radiationcameras from Mirion IST will provide fullcoverage of the Chernobyl plant and alloperations during the next phase of theproject as workers are located remotely andwill perform nearly all operations usingcameras.

The MTP is illustrated in Figures 4and 5.

The mobile tool platform is anexclusive design by the crane supplier andhas the following features:

• Provides 1.5 tonne side load capacitywith <0.5m deflection at full extension35m (115ft). Could have the capabilityto move the lower platform laterallywhile the upper platform remains stillthrough hoist control (flying);

• Is used for tool deployment, includingmanipulator arm, core drill, concretecrusher and 10 tonne vacuum cleaner;

• Power (175kW) is supplied throughoutthe vertical travel range 70m (230ft).

The authors believe that this is thelargest implementation of a tensile trussdesign for these purposes. Because it is firstof a kind, the manufacturer constructed a25 percent scale prototype in PaR’s facilityin the USA (as shown on the cover of thisissue). The prototype was used for proof ofprinciple and to develop the sophisticatedcontrol system necessary for operation. Thescale model tensile truss is fully functionaland has been used by PaR Systems to provethe sophisticated software necessary to

perform straight-line raising and loweringfunctions as well as develop complicatedmovements such as horizontal flying androtation using motor control. Flying isachieved by precision control of the sixhoists which moves the lower platformhorizontally merely by varying the ropelengths. The lower platform can also bemanipulated to various orientations whichincreases the functionality of the attachedtools (see Figure 6).

MTP PROTOTYPE TESTINGBecause of the physical size of the MTP,actual side load testing over the entiretravel range of the MTP cannot beaccomplished until final site installation. Tohelp validate the full scale MTPperformance PaR used the 1/4 scale versionof the MTP to develop a Predictive Softwarepackage. Extensive load testing is beingdone on the 1/4 scale MTP. These resultswill be used to validate the accuracy of thePredictive Software. Full scale MTP sideload and deflection information will thenbe estimated using the Predictive Softwarepackage.

Figure 4: Mobile Tool Platform suspended fromEast bridge

Figure 5: Mobile Tool Platform, detailed view

Figure 6: Scale Model Tension Truss LowerPlatform – using hoist control to achieve variousorientations.


22 LIFT AND HOIST INTERNATIONAL • LIFTANDHOIST.COM

GARAGES: CARRIAGE TRANSFER AND MAINTENANCEThe MCS consists of two bridges and three carriages. Any twocarriages can be placed on either bridge at one time. There are twogarages to enable transfer of carriages between bridges and to providecarriage maintenance space. Two carriages can be stored in eithergarage simultaneously.

For example, suppose that it is desired to transfer the securecarriage from the eastern bridge to the western bridge. The easternbridge is aligned with the single-story southern garage, the bridge islocked into place, and the carriage is driven into the garage. Then theeastern bridge is moved away, the western bridge aligned with thegarage and locked into place, and the carriage is driven onto thebridge.

The northern garage is a shielded three-story facility outfittedwith hoists and other maintenance equipment to enablemaintenance, repair, and, if necessary, complete disassembly ofcarriages at elevation. The lower platform of the MTP is lowered to aspecial stand at ground level for maintenance, to empty the vacuumcollection system, and tool change-outs or replacement ofconsumables.

CRANE CONTROL AND OPERATIONIf the MCS were to drop a heavy load over the Chernobyl Unit 4 reactorhall, a radioactive dust cloud would be generated. The NSC wouldprevent the dust from reaching the environment or endangeringworkers and the public outside of the NSC. However, the dust wouldbe a significant hazard to anyone inside the NSC at that time. Nopersonnel will be inside the NSC during such lifts.

MCS operations will be performed by operators located outside ofthe NSC, without line-of-sight of the crane or its load. Consequently,the MCS is more heavily instrumented than a similar crane withoutthis constraint. The radiation environment inside the NSC alsoimpacts instrumentation and control design.

The MCS Control Architecture consists of state-of-the-artprogrammable logic controllers (PLC), wireless and Ethernethardware technologies along with human and machine interface(HMI). All operator commands are delivered to the crane system usinga wireless control system. The operators sit at consoles equipped withjoysticks and several touch screen monitors that provide MCS positionand status, including load weighing system outputs. Other monitorsdisplay closed circuit television images of load and crane movement.There are also cameras located on the carriages and bridges used forcommon pre-operational checks.

Two of the more complex operations executed by the controlsystem are simultaneous operation and synchronous operation.Synchronous operation allows single point control for theSynchronous lifting or translocation of two carriages on the same ordifferent bridges. This type of operation is necessary for lifting andmoving long loads. Simultaneous operation allows single pointcontrol for the rotation of a long load being carried by two carriageson different bridges.

INTERNATIONAL ASPECTS OF DESIGN AND MANUFACTUREThe MCS components are designed, fabricated, and tested to the UScodes and standards. The primary design code for the MCS is theAmerican Society of Mechanical Engineers Rules for Construction ofOverhead and Gantry Cranes (Top Running Bridge, Multiple Girder),ASME NOG-1-2004. UkrKranEnergo, the leading Ukrainian expert inthe design and manufacturing of crane equipment for variousindustrial applications, including nuclear power plants, performedreconciliation of ASTM materials standards, ASME-NOG-1, and AWSwelding standards to the applicable Ukrainian codes and standards.These reconciliation analyses demonstrated that the MCS designeither meets or exceeds Ukrainian codes and standards. Such codereconciliations are one of the most difficult aspects of internationaldesign and manufacturing.

MTP compared to Test Platform

DESIGN AND FABRICATION STATUSSince the issuance of the MCS contract, several design reviewmeetings were held in the US and in Ukraine. At the time ofpublication, 99 percent of the MCS design is complete. PaR hasissued purchase orders to its subcontractors for the supply ofvarious components. The MCS carriages and bridge girders arevery close to completion of fabrication. The factory acceptancetesting of the MCS is scheduled in May 2013 and the shipment isscheduled in March 2014. The contract completion date for theNew Safe Confinement is October 2015.

IF THE MCS WERE TODROP A HEAVY LOADOVER THE CHERNOBYLUNIT 4 REACTOR HALL,A RADIOACTIVE DUSTCLOUD WOULD BEGENERATED. THE NSCWOULD PREVENT THEDUST FROM REACHINGTHE ENVIRONMENT ORENDANGERINGWORKERS AND THEPUBLIC OUTSIDE OFTHE NSC.

cranes at chernobyl - robotic automation · pdf filethe day concluded with a presentation from...

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