Objectives

In the framework of the "Tacis Nuclear Safety Programme" it was decided to provide the South Ukraine NPP, Ukraine with an on-site assistance (OSA) and supply programme with the aim of improving the operational safety of the plant. One part of the programme was the replacement of the thermal insulation of the primary circuit of unit 3 of the South Ukraine NPP. This was needed in order to reduce the probability of common cause failure of the emergency spray system and the emergency core cooling system (ECCS) during and after a loss-of-coolant accident (LOCA). The supplied thermal insulation was of the cassette thermal insulation type with mineral wool or fibre glass blanket insulation material and was intended for the following piping sections of the primary circuit:

• Main circulation pipelines
• Main circulation pumps volutes
• Connecting pipe between pressurizer and primary circuit loop
• Connection pipe between ECCS hydraulic accumulator and reactor pressure vessel (RPV)

The supplier was responsible for the design (including calculations), procurement of raw materials, fabrication, shipment, pre-installation storage, on-site installation, inspection & tests and documentation of the thermal insulation. It had to comply with all relevant Ukrainian standards & regulations, all relevant ASTM (or European equivalents) standards and with the US NRC regulatory guides 1.36 and 1.82.

Project Results

The supply contract was awarded to IBERDROLA Ingenieria y Construccion S.A.U. of Spain. The installation of the thermal insulation was carried out between 24th September and 14th November 2007. The provisional acceptance certificate was signed on the 8th April 2008.