A major stage of the clean-up operation at Chernobyl nuclear power plant has been completed.
The nuclear power plant recently commemorated the 30th anniversary of the catastrophic explosion of reactor four, which occurred on 26 April 1986.
Work has now been completed to erect the end walls for the New Safe Confinement (NSC) enclosing perimeter project, which has involved the building of a giant arch-shaped structure – tall enough to house London’s St Paul’s Cathedral. The structure will completely cover the shelter that houses the stricken reactor.
The arch has been built in two halves and will be joined together to complete the structure. Erecting the end walls will allow the sliding of the arch into its design position.
The large structure is the most prominent part of the Chernobyl Shelter Implementation Plan (SIP), which has provided a step-by-step strategy for the decisions required to develop a safety programme for the site.
Day-to-day work on the SIP at the site is overseen by the project management unit (PMU), formed of experts from Bechtel and the staff of the Chernobyl nuclear power plant.
“In total, 9,600m3 of concrete and about 1,500t of re-bar [reinforcement] was used during the work performance,” said SIP PMU deputy project and program manager Viktor Popovskyi.
The scope of works has included:
- The reinforcement and sealing of the existing II Stage ChNPP (power units number three and four) structures, upon which the arch end walls will be abutted
- Design and construction of new dividing walls within the existing structures of the Turbine Hall
- The installation of new structural supports in the “de-areator” to reduce the risk of collapse
- Installation of heavy-duty cranes and auxiliary systems for the safe operation of the NSC and for future dismantling and waste-management activities
- Preparation of the existing surfaces for installation and attachment of sealing anchors.
Popovskyi said that tens of tonnes of technological equipment and metal structures have been dismantled, as well as hundreds of cubic meters of concrete that has been removed and transported out to allow the team to start works on erecting the new dividing walls.
He added that the project complexity had been dictated by the variation of the actual conditions at the site from the initial design solutions, as well as by the risk of severe radiation and high dose rates for personnel.
Popovskyi explained that it was important to emphasise that the works had been completed ahead of schedule. He said that this has allowed the team to start the early dismantling of crane runways of a heavy lift crane, Potain MD 1100, which was used during the construction.
A geodetic survey of the performed works and preparation of as-built documentation are now underway on site.
The heavy lift crane is expected to be dismantled during 7 to 28 October, following which the site will be handed over to Novarka – a joint venture formed by contractors Vinci and Bouygues – for continuation of works.
The entire SIP is expected to cost €2.1bn (£1.85bn) and to be completed by 2017. It is funded by contributions from more than 40 countries and organisations.