Replacement of Thermal Insulation on Pipe-work in the RB

In Sipro we have established project documentation for the replacement of thermal insulation on piping in the reactor building of Nuclear power plant Krško. Companies placing the order were TRANSCO Products Inc. Chicago, USA and Numip Ltd. Ljubljana, who was the performer of the installation. Modification is labeled 542-RC-L and constitutes solution to the requirements of NRC Bulletin 2003-1 »Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized Water Reactors«.


Picture: Transco Drawing of MRI Segment

The above mentioned report notes that classic insulation materials (deliquescent and fibrous materials, like calcium silicate, glass wool etc.) are removed due to the possibility of blocking the suction of recycling pumps in the case of containment emergency cooling needs.


Picture: MRI Segment

The replacement insulation is known as MRI (Metal Reflective Insulation), constructed of stainless steel material. On the basis of heat calculations the thickness of MRI was defined, considering particular piping thermal requirements and construction conveniences. Seismic calculation of mechanical insulation integrity for operation during postulated earthquake was made, as demanded for all nuclear safety related systems in NPP Krško. Insulation was replaced on the following Safety Related systems operating in temperature range between 110 and 325 degrees Celsius: RC (Reactor cooling), CS (Chemical and volume control), SI (Safety injection), RH (Residual heat removal), WP (Waste processing), AF (Auxilliary Feedwater), FW (Feed water) and BD (Blow down). Project was performed during the outage R2007.

                                                                    Project Manager: Mladen Debeljak, B.Sc.M.E.