2012-10 – Lift & Hoist International – Cranes at Chernobyl – Work continues in the aftermath of the nuclea power plant disaster of 1986

2012-10 - Lift & Hoist International - Cranes at Chernobyl - Work continues in the aftermath of the nuclea power plant disaster of 1986

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SHOW REVIEW
Lifting and rigging
equipment in the
spotlight at PLASA 2012,
staged at London’s Earls
Court
INTERVIEW
Spain-based material
handling specialist and
weighing systems
provider Airpes has
adapted in the wake of
recession
SHOW PREVIEW
Now in its eighth year,
LiftEx 2012 takes place
29-30 November at the
Ricoh Arena, Coventry, UK
AERIAL WORK
PLATFORMS
A German-made compact
tracked lift was used for
maintenance work at a
unique facility in New York
ISSUE NUMBER 6 • SEPTEMBER/OCTOBER 2012
LIFT & HOIST
INTERNATIONAL
CRANES AT
CHERNOBYL
liftandhoist.com
EVERY ISSUE: Overhead Cranes and Hoists • Access Platforms • Lift Trucks • Controls and Components
WORK CONTINUES
IN THE AFTERMATH
OF THE NUCLEAR
POWER PLANT
DISASTER OF 1986
LIFT AND HOIST INTERNATIONAL • LIFTANDHOIST.COM 5
LHI welcomes special report from one of the most
fascinating overhead crane projects in the world.
Five years ago I chaired an overhead crane
breakout session at a conference in London.
The day concluded with a presentation from
Eric Schmieman, who, at the time, was safety
manager at the Chernobyl containment project,
where overhead cranes would work in the aftermath of
the shocking, devastating Chernobyl accident that
occurred on April 26, 1986, destroying Unit 4 at the
nuclear power plant.
Conference delegates listened as Schmieman
explained how cranes would work in the
deconstruction and safe disposal of the accident
consequences in a New Safe Confinement (NSC) on the
site of the most catastrophic disaster in the history of
commercial nuclear power.
I was hooked on the project and have kept in touch
with Schmieman—he works at the global research and
development organisation, Battelle Memorial
Institute—ever since. I am delighted that we can
publish in this issue a special report from Chernobyl by
Schmieman, corresponding author Vijay
Parameswaran, of Bechtel International Systems, Inc.,
and their colleagues.
An international tender was initiated in 2004 for
design and construction of the NSC. A subcontract for
the design and manufacture of the main crane system
was awarded to US-based PaR Systems, Inc.
One of many fascinating dimensions of the project
is the mobile tool platform, which is connected to the
crane carriage. The tool platform is a custom-made tensile truss that
will serve as a stable platform for remotely operated tools. A robotic arm
is attached to a rotating mounting plate to allow work to be performed
in a complete hemisphere. Remotely operated high radiation cameras
will provide full coverage of the Chernobyl plant and all operations
during the next phase of the project as workers are located remotely and
will perform nearly all operations using cameras.
The authors believe that this is the largest implementation of a
tensile truss design for these purposes—and I certainly can’t contest
that. Because it is first of a kind, the manufacturer constructed a 25
percent scale prototype in the US, which is this issue’s cover image.
Read more about the project from page 18.
CONFERENCE
DELEGATES HEARD
HOW CRANES
WOULD WORK IN
THE
DECONSTRUCTION
AND SAFE DISPOSAL
OF THE CHERNOBYL
ACCIDENT
CONSEQUENCES IN A
NEW SAFE
CONFINEMENT
EDITOR’S LETTER
RICHARD HOWES, EDITOR
HOOKED
SUBSCRIPTIONS TO LIFT & HOIST INTERNATIONAL
1 year (6 issues) UK & Europe £55.00/€70.00 • USA & Canada $102 • Rest of the World $162
INTERNATIONAL
LIFT & HOIST
SEPTEMBER/OCTOBER 2012
ISSUE 6
Lift & Hoist International
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Access, and Crane & Rigging Hot Line; and ILH
eNews and Lifting 360 eNewsletters
SPECIAL REPORT – CRANES AT CHERNOBYL
18 LIFT AND HOIST INTERNATIONAL • LIFTANDHOIST.COM
BACKGROUND The Chernobyl nuclear power plant
(ChNPP) accident that occurred on April
26, 1986 destroyed Unit 4. After the
accident situation was stabilised, it became
apparent that sequestration of the damaged
reactor was necessary to minimise long term
radiological impact on personnel and the
environment. A temporary confinement
building, the Object Shelter (OS), was
designed and constructed between May and
November 1986.
The primary purpose of the Object
Shelter was to prevent further spreading of
the radioactive dust and debris. It was built
under extremely difficult and hazardous
conditions and was intended to last 30 years.
Upon completion of construction, the
building had more than 1,000 sq m of
openings that allowed some dust to escape
and water to enter the steel structure.
Although some measures have been
taken in the past 26 years to stabilise the
structure and reduce corrosion, the risk of
collapse of the Object Shelter continues to
increase over time. Its confinement function
needs to be performed by a new structure,
and the Object Shelter needs to be dismantled
in an orderly manner.
The structural elements being
dismantled will be large and heavy. Nuclear
fuel material and other radioactive waste will
be placed in heavy shielded containers. The
dismantling activities and handling of heavy
shielded waste disposal casks will require
large and sophisticated cranes that are the
subject of this paper.
In 1997 the G-7 nations prepared the
Shelter Implementation Plan (SIP) for the
conversion of the OS into an ecologically safe
system. The SIP consists of 22 tasks, the
largest of which is the design and
construction of a New Safe Confinement
(NSC).
The NSC will be constructed adjacent to
the OS to minimise radiation doses to
construction workers, then slid over the OS
on a runway system using hydraulic power.
The NSC is an enormous arch-shaped steel
structure which will protect the OS from the
elements, confine any radioactive dust
releases, and support a massive and unique
crane system. The approximate dimensions of
the NSC arch are 250m wide, 150m long, and
100m tall. A section of the NSC is illustrated in
Figure 1.
A donor community, consisting of 46
countries and organisations, support the
work of the SIP. Funds are administered by
the European Bank for Reconstruction and
Development (EBRD). The facility owner is
State Specialised Enterprise Chernobyl
Nuclear Power Plant (ChNPP). Oversight of
SIP work is provided by a Project
Management Unit (PMU) staffed by
MASSIVE AND UNIQUE
The design and manufacture of the main cranes system was integral to the New Safe Confinement
project at Chernobyl, the scene of a nuclear power plant disaster in April 1986.
THE AUTHORS
N. 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 Kedrowski
and Rob Owen, both PaR Systems, Inc. (USA); Eric Schmieman, Battelle Memorial
Institute (USA).
Figure 1: New Safe Confinement section looking East
SPECIAL REPORT – CRANES AT CHERNOBYL
LIFT AND HOIST INTERNATIONAL • LIFTANDHOIST.COM 19
representatives of ChNPP and a consortium of
Bechtel International Systems Incorporated
(Bechtel) and Battelle Memorial Institute
(Battelle).
An international tender was initiated in
2004 for design and construction of the NSC.
The contract was awarded in 2007 to
NOVARKA, a joint venture between Vinci
Construction Grands Projets and Bouygues
Travaux Publics. NOVARKA subsequently
awarded a subcontract for design and
manufacture of the Main Cranes System
(MCS) to PaR Systems, Inc.
(Minneapolis/Saint Paul, Minnesota, USA).
The MCS is installed just below the NSC
ceiling, approximately 80m (275ft) above
ground level. The MCS will be installed in two
large lift operations inside the NSC by
NOVARKA under technical supervision
provided by PaR. The MCS will be installed
and tested in the non-radioactive assembly
area before arch sliding.
The following presents some
engineering details and unique features of
the 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; 50
tonnes capacity
• One secure carriage hoist
• Dual hoist configuration; 40 tonnes
capacity (personnel)/50 tonnes
capacity (materials)
• May be utilised to transfer
maintenance personnel throughout
the facility in a shielded protective
box
• One mobile tool platform carriage (MTP)
• Quantity of six hoists operating
simultaneously to hoist and lower a
platform with a tool arm on the
underside
• Lower platform attachments such
as hydraulic power unit, vacuum
system, arm/tooling supplied by
others
• Runway rails and conductor bars
• Control system and camera system
• On site erection supervision
Figures 2 and 3 provide an appreciation
of the extraordinary size of the MCS
components. To demonstrate scale, a Boeing
777 is illustrated parked below the bridges
and in front of the NSC.
BRIEF DESCRIPTION AND FUNCTIONS OF
EACH MAJOR MCS COMPONENT:
CRANE BRIDGES
Two crane bridges are top-running
underhung, suspended from crane rails
oriented East-West and located at an
elevation of 76m inside the NSC. Due to their
considerable length (96m), each bridge
moves on six crane rails. Each girder has five
individual pinned spans to provide the
flexibility to maintain wheel contact for
different load cases and arch movement. The
bridges are designed such that two fully
loaded carriages may be on the same bridge
with a separation of at least 22m centre-to
centre. The control cabinets are located on
the bridge with wireless communication to
the control room. Although local control from
these panels is possible, the cranes are
normally operated from a control room
located in a building separate from the NSC.
The crane bridges are also equipped with
access ways for maintenance of the bridges.
CLASSIC CARRIAGE
The classic carriage is a top running trolley
with one drum. It has four driven wheels and
four idler wheels to support garage transfer
activities. The carriage wheelbase is 6.5m
(21ft) by 7.0m (23ft). Carriage travel speed is 0
to 15 m/min. Lifting capacity is 50 tonnes.
Lifting speed: 0 to 10 m/min. Vertical lifting
distance of 73m (240 ft). Continuous hook
rotation at 0.25 RPM. Carriage controls are
located on the trolley with wireless
communication to the control room.
SECURE CARRIAGE
The secure carriage is a top running trolley
with two drums. It has four driven wheels
and four idler wheels to support garage
transfer activities. The carriage wheelbase
is 6.5m (21ft) by 7.0m (23ft). Carriage travel
speed is 0 to 15 m/min. Lifting capacity is
50 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 rotation
at 0.25 RPM. Carriage controls are located
on the trolley with wireless communication
to the control room.
In order to allow worker access to high
radiation areas of the Object Shelter, the
Figure 2: NSC
compared to
Boeing 777, same
scale
Figure 3: MCS
bridges compared
to Boeing 777,
same scale
Secure carriage
Classic carriage
SPECIAL REPORT – CRANES AT CHERNOBYL
LIFT AND HOIST INTERNATIONAL • LIFTANDHOIST.COM 21
NSC is equipped with a shielded protective
box. Workers can be transported in the
shielded protective box only by the MCS
secure carriage. The secure carriage can be
used in cooperation with the classic
carriage to lift beams with a length >50m
and weight of up to 100 tonnes.
CARRIAGE EQUIPPED WITH MOBILE TOOL
PLATFORM (MTP)
The MTP is a custom-made tensile truss that
will serve as a stable platform for remotely
operated tools. The MTP is composed of two
triangular shaped platforms, upper and
lower, connected by six wire ropes. The six
hoists on the upper platform allow raising
and lowering of the lower platform to the
work area. The hoists also precisely control
tension on each wire rope so that the lower
platform can sustain significant horizontal
loads and torque generated by the use of
the tools. The MTP design is much more
than the standard anti-sway technology
used in the crane industry—it is an inverted
Stewart Platform and has the same
properties as a rigid structural element.
The rigid platform provides an ideal
delivery system for remote tooling that will
be required in the Chernobyl dismantling
efforts in the future. For the Chernobyl
application, a robotic arm is attached to a
rotating mounting plate to allow work to be
performed in a complete hemisphere below
the MTP. Remotely operated high radiation
cameras from Mirion IST will provide full
coverage of the Chernobyl plant and all
operations during the next phase of the
project as workers are located remotely and
will perform nearly all operations using
cameras.
The MTP is illustrated in Figures 4
and 5.
The mobile tool platform is an
exclusive design by the crane supplier and
has the following features:
• Provides 1.5 tonne side load capacity
with <0.5m deflection at full extension 35m (115ft). Could have the capability to move the lower platform laterally while the upper platform remains still through hoist control (flying); • Is used for tool deployment, including manipulator arm, core drill, concrete crusher and 10 tonne vacuum cleaner; • Power (175kW) is supplied throughout the vertical travel range 70m (230ft). The authors believe that this is the largest implementation of a tensile truss design for these purposes. Because it is first of a kind, the manufacturer constructed a 25 percent scale prototype in PaR’s facility in the USA (as shown on the cover of this issue). The prototype was used for proof of principle and to develop the sophisticated control system necessary for operation. The scale model tensile truss is fully functional and has been used by PaR Systems to prove the sophisticated software necessary to perform straight-line raising and lowering functions as well as develop complicated movements such as horizontal flying and rotation using motor control. Flying is achieved by precision control of the six hoists which moves the lower platform horizontally merely by varying the rope lengths. The lower platform can also be manipulated to various orientations which increases the functionality of the attached tools (see Figure 6). MTP PROTOTYPE TESTING Because of the physical size of the MTP, actual side load testing over the entire travel range of the MTP cannot be accomplished until final site installation. To help validate the full scale MTP performance PaR used the 1/4 scale version of the MTP to develop a Predictive Software package. Extensive load testing is being done on the 1/4 scale MTP. These results will be used to validate the accuracy of the Predictive Software. Full scale MTP side load and deflection information will then be estimated using the Predictive Software package. Figure 4: Mobile Tool Platform suspended from East bridge Figure 5: Mobile Tool Platform, detailed view Figure 6: Scale Model Tension Truss Lower Platform – using hoist control to achieve various orientations. SPECIAL REPORT - CRANES AT CHERNOBYL 22 LIFT AND HOIST INTERNATIONAL • LIFTANDHOIST.COM GARAGES: CARRIAGE TRANSFER AND MAINTENANCE The MCS consists of two bridges and three carriages. Any two carriages can be placed on either bridge at one time. There are two garages to enable transfer of carriages between bridges and to provide carriage maintenance space. Two carriages can be stored in either garage simultaneously. For example, suppose that it is desired to transfer the secure carriage from the eastern bridge to the western bridge. The eastern bridge is aligned with the single-story southern garage, the bridge is locked into place, and the carriage is driven into the garage. Then the eastern bridge is moved away, the western bridge aligned with the garage and locked into place, and the carriage is driven onto the bridge. The northern garage is a shielded three-story facility outfitted with hoists and other maintenance equipment to enable maintenance, repair, and, if necessary, complete disassembly of carriages at elevation. The lower platform of the MTP is lowered to a special stand at ground level for maintenance, to empty the vacuum collection system, and tool change-outs or replacement of consumables. CRANE CONTROL AND OPERATION If the MCS were to drop a heavy load over the Chernobyl Unit 4 reactor hall, a radioactive dust cloud would be generated. The NSC would prevent the dust from reaching the environment or endangering workers and the public outside of the NSC. However, the dust would be a significant hazard to anyone inside the NSC at that time. No personnel will be inside the NSC during such lifts. MCS operations will be performed by operators located outside of the NSC, without line-of-sight of the crane or its load. Consequently, the MCS is more heavily instrumented than a similar crane without this constraint. The radiation environment inside the NSC also impacts instrumentation and control design. The MCS Control Architecture consists of state-of-the-art programmable logic controllers (PLC), wireless and Ethernet hardware technologies along with human and machine interface (HMI). All operator commands are delivered to the crane system using a wireless control system. The operators sit at consoles equipped with joysticks and several touch screen monitors that provide MCS position and status, including load weighing system outputs. Other monitors display closed circuit television images of load and crane movement. There are also cameras located on the carriages and bridges used for common pre-operational checks. Two of the more complex operations executed by the control system are simultaneous operation and synchronous operation. Synchronous operation allows single point control for the Synchronous lifting or translocation of two carriages on the same or different bridges. This type of operation is necessary for lifting and moving long loads. Simultaneous operation allows single point control for the rotation of a long load being carried by two carriages on different bridges. INTERNATIONAL ASPECTS OF DESIGN AND MANUFACTURE The MCS components are designed, fabricated, and tested to the US codes and standards. The primary design code for the MCS is the American Society of Mechanical Engineers Rules for Construction of Overhead and Gantry Cranes (Top Running Bridge, Multiple Girder), ASME NOG-1-2004. UkrKranEnergo, the leading Ukrainian expert in the design and manufacturing of crane equipment for various industrial applications, including nuclear power plants, performed reconciliation of ASTM materials standards, ASME-NOG-1, and AWS welding standards to the applicable Ukrainian codes and standards. These reconciliation analyses demonstrated that the MCS design either meets or exceeds Ukrainian codes and standards. Such code reconciliations are one of the most difficult aspects of international design and manufacturing. MTP compared to Test Platform DESIGN AND FABRICATION STATUS Since the issuance of the MCS contract, several design review meetings were held in the US and in Ukraine. At the time of publication, 99 percent of the MCS design is complete. PaR has issued purchase orders to its subcontractors for the supply of various components. The MCS carriages and bridge girders are very close to completion of fabrication. The factory acceptance testing of the MCS is scheduled in May 2013 and the shipment is scheduled in March 2014. The contract completion date for the New Safe Confinement is October 2015. IF THE MCS WERE TO DROP A HEAVY LOAD OVER THE CHERNOBYL UNIT 4 REACTOR HALL, A RADIOACTIVE DUST CLOUD WOULD BE GENERATED. THE NSC WOULD PREVENT THE DUST FROM REACHING THE ENVIRONMENT OR ENDANGERING WORKERS AND THE PUBLIC OUTSIDE OF THE NSC.