The State Nuclear Regulatory Inspectorate of Ukraine agreed upon the technical decision on eliminating the defects of SSE ChNPP II Generation New Ventilation Stack (NVS) metal structures.
The Action Plan on eliminating the defects is attached to the technical decision. According to this Plan a working documentation on remedial measures that improve the NVS reliability and on eliminating the defects of NVS tower’s metal structures should be developed within 30 calendar days after the agreement by the Designer (KSK Consortium composed of Kyiv Institute “Energoproekt”, Scientific Research Institute for Building Structures and Institute for NPP Safety Problems) with the involvement of the Nominated Subcontractor – Ye.Paton Institute. Welding work technology will be developed in parallel. After the working documentation review by the Employer and expert assessment at the SE “Ukrderzhbudexpertise”, the work execution projects, in accordance with which the physical activities on eliminating the defects to be performed, will be developed and then reviewed by the SNRIU.
The measures on designing, agreement and execution are envisaged for five months. The works will be financed at the expense of the Chernobyl Shelter Fund.

FYI
Construction and erection works on assembling the NVS metal structures were performed under the relevant contract within the Shelter Implementation Plan (SIP) in March 2012.
On July 11, 2012, during the routine inspection of the NVS metal structures’ condition by the designer's supervision personnel, the defects of joint welds in gusset plates of the NVS tower at marks 100.00, 107.56 and 114.76 in the form of “hair” cracks along the welding joints, which connect the gusset plates 12 mm in thickness and a pipe 325 mm in diameter, were detected.  The cracks development was observed in the top-bottom direction. These joint welds were produced at the manufacturing factory (Kharkiv).
“The Action Plan on the NVS engineering survey, investigation of causes for defects and measures on their repair” was developed by the SSE ChNPP for determining the causes for defects of the NVS metal structures and elaboration of high priority measures on their elimination. It was submitted to the SNRIU on 13.09.2012. The NVS Project Designer, KSC Consortium, carried out additional surveys and developed the Report “Analysis of causes for formation of cracks in the NVS structures and recommendations on further actions”. The technical decision on eliminating the defects of the New Ventilation Stack metal structures was developed based on these documents.

On April 18 in the morning, the Prypiat River water level reached 107 meters of gauge height (under Baltic System). According to internal documents of Chernobyl NPP, the specific flood-protection activities are introduced at the enterprise when flood waters reach specified level. The objective of these activities is to prevent damage of the cooling pond dam and ingress of service water into the Prypiat River.

Pursuant to internal procedures, the round-the-clock duty charts for engineering staff of the hydro-technical facilities are established during flooding. Among these activities, there are dam detours twice a day, additional surveys of downstream side of dam and channels, their cleaning if required.

Moreover, the inventory of construction materials is currently prepared for elimination of dam defects, if they occur, and for detours using special transport, which could be needed in case of threat for dam body damage.

It is also assumed to keep continuous communication with Hydro-Meteorological Center of Ukraine, Meteorological Station located in Chernobyl town, “Ecocenter” enterprise, etc. to specify meteorological forecasts and situation in the river.

Prior to flood occurrence, the enterprise commission has reviewed and drew up an act for a dam, and its state was recognized satisfactory.

As previously informed, on 9^th of April 2013, the Vice Prime Minister of Ukraine Yuriy Boyko officially visited the SSE “Chernobyl NPP” site. Based on the results of official visit and progress review of the Chernobyl NPP Units Decommissioning and the Shelter Transformation into Ecologically Safe System projects, and to improve efficiency of using available infrastructure of Chernobyl NPP for energy industry of Ukraine, on April 12, the Vice Prime Minister of Ukraine Yuriy Boyko gave appropriate instructions:
- The Ministry of Ecology and Natural Resources, the Ministry of Energy and Coal Industry, the State Agency for Exclusion Zone Management, the State Nuclear Regulation Inspectorate, the Kyiv Regional State Administration, and SE NAEC “EnergoAtom”, by 1^st of May 2013, are entrusted to create an inter-agency working group chaired by the Deputy Minister of Ecology and Natural Resources Dmytro Mormul to work out a strategy of further development of Chernobyl site taking into account solving of Ukrainian Nuclear Industry issues on centralized management of spent nuclear fuel and radioactive waste;
- The Ministry of Energy and Coal Industry and the State Agency for Exclusion Zone Management, by 1^st of August 2013, are entrusted to hand over electricity generation facility “Outdoor Switchgear (OSG) 110/330/750 kW” from the balance sheet of SSE “Chernobyl NPP” to the balance sheet of SE NEC “UkrEnergo”.

For reference:
The OSG-110/330/750 kW was designed to output to the energy system the electric power generated by operating power units of ChNPP, and provide transit of electric power using transmission and cross-border networks, provide electric power to the plant’s units, auxiliary facilities and other consuming facilities of the region adjacent to ChNPP area.
Since Units shutdown, the OSG-110/330/750 kW is still functioning practically to the full extent ensuring connection between separate energy systems of the unified energy system of Ukraine, and power delivery to it from KhNPP Units. Moreover, using OSG-330/750 kW, the electric power supplies are exported to the Republic of Belarus, the electric power is delivered from transmission networks to CJSC “AES KyivOblEnergo” networks and supplied for SSE ChNPP needs.

The State Nuclear Regulatory Inspectorate of Ukraine agreed upon the technical decision on eliminating the defects of SSE ChNPP II Generation New Ventilation Stack (NVS) metal structures.
The Action Plan on eliminating the defects is attached to the technical decision. According to this Plan a working documentation on remedial measures that improve the NVS reliability and on eliminating the defects of NVS tower’s metal structures should be developed within 30 calendar days after the agreement by the Designer (KSK Consortium composed of Kyiv Institute “Energoproekt”, Scientific Research Institute for Building Structures and Institute for NPP Safety Problems) with the involvement of the Nominated Subcontractor – Ye.Paton Institute. Welding work technology will be developed in parallel. After the working documentation review by the Employer and expert assessment at the SE “Ukrderzhbudexpertise”, the work execution projects, in accordance with which the physical activities on eliminating the defects to be performed, will be developed and then reviewed by the SNRIU.
The measures on designing, agreement and execution are envisaged for five months. The works will be financed at the expense of the Chernobyl Shelter Fund.

FYI
Construction and erection works on assembling the NVS metal structures were performed under the relevant contract within the Shelter Implementation Plan (SIP) in March 2012.
On July 11, 2012, during the routine inspection of the NVS metal structures’ condition by the designer's supervision personnel, the defects of joint welds in gusset plates of the NVS tower at marks 100.00, 107.56 and 114.76 in the form of “hair” cracks along the welding joints, which connect the gusset plates 12 mm in thickness and a pipe 325 mm in diameter, were detected.  The cracks development was observed in the top-bottom direction. These joint welds were produced at the manufacturing factory (Kharkiv).
“The Action Plan on the NVS engineering survey, investigation of causes for defects and measures on their repair” was developed by the SSE ChNPP for determining the causes for defects of the NVS metal structures and elaboration of high priority measures on their elimination. It was submitted to the SNRIU on 13.09.2012. The NVS Project Designer, KSC Consortium, carried out additional surveys and developed the Report “Analysis of causes for formation of cracks in the NVS structures and recommendations on further actions”. The technical decision on eliminating the defects of the New Ventilation Stack metal structures was developed based on these documents.