India’s first indigenous 700 MWe pressurized heavy water reactor, Kakrapar 3, received its first calandria end shield on 29 May into the calandria vault.
The structure, filled with carbon steel balls (for shielding), was 228t.
The same crane was recently used to install entire segments of the containment ring at unit 3.
The end shields are a key component of a pressurized heavy water reactor. As the name suggests an end shield closes off each end of the calandria vessel and serves to support the entire calandria assembly.
India’s nuclear regulator the Atomic Energy Regulatory Board granted clearance for installation of the calandria end shields at KAPS 3&4 on 23 May 2014. It is valid until end of March 2016, subject to various conditions.
For instance, AERB says that grouting of the end shield must only be undertaken after regulatory approval and once it has results of mock-ups on grout. It also stipulated that measure to protect against an external flood at the Kakrapar site be implemented as ‘top-most priority.’ AERB will also increase the frequency of site regulatory inspections over the next few quarters.
First concrete pouring was completed on Kakrapar unit 3 in November 2010, and at unit 4 in March 2011, according to NPCIL. KAPS 3&4 are expected to be completed in June 2015 and December 2015, respectively.
Other construction milestones still to come on unit 3 include: completing alignment and welding of the calandria end shield, and grouting; installing calandria tubes; completing collant channel installation and erection of feeders. These will be followed by PHT hydro test, hot conditioning of PHT system and then criticality.
