ANPP Director General: Stress test at Armenian NPP by European Commission has nothing to do with Unit 2 Lifetime Extension Project  

ArmInfo. The stress test at the Armenian Nuclear Power Plant (NPP) by the European Commission has nothing to do with the Unit 2 Lifetime Extension Project, ANPP Director General Movses Vardanyan said on Sept 9, when replying to ArmInfo's question.   

He said that after the Fukushima accident almost all countries, including Russia, have conducted their stress tests. At the request of the European Commission, in 2012-2014 the ANPP underwent a stress test. After that a national report was prepared and sent to the European Commission. For its part, the European Commission suggested conducting 47 measures at the ANPP towards enhancement of its safety. The Plant itself has conducted more than half of the measures, while the remaining part needs financial means and the European Commission agreed to provide the funds. 

"I'd like to recall that after we took a decision to extend the Unit 2 lifetime, the European Commission stopped assisting the ANPP. Now its stand has changed and it will continue providing support, including financial one," he said. Vardanyan added that the European Commission thinks a big quake may occur on the NPP site. But this problem was considered earlier as well. After the Spitak earthquake of 1988, the requirements to the ANPP seismic safety grew.

He noted that the European Commission's support will mostly consist of mobile equipments - generators, diesel fuel pumps, etc. In case of a major quake on the NPP site, which isolates the plant from the world within 72 hours, the NPP employees can use the mobile equipment and ensure the Plant's safety themselves.  But in general, he said, the WWER-440 units are the most reliable and the most conservative units.  They have a big safety factor. "This is why, the European Commission did not exert much pressure," he said.   

To recall, the European Commission experts have finished studying the national report on comprehensive assessment of risks and safety of the Armenian NPP.

According to the executive summary of Armenia Stress Tests Peer Review held between 20 and 24 June 2016, the geological situation of Armenia is characterized by its location at the collision zone between the Arabic and Eurasian tectonic plates with high crustal deformation rates, abundant active faults, and numerous quaternary volcanoes. This geodynamic framework and the past experiences with numerous severe earthquakes such as the 1988 Spitak earthquake require putting particular emphasis on seismic safety. The authors of the document note that in the past, ANPP and ANRA have undertaken continued efforts to ensure and improve the seismic safety of the ANPP. The Peer Review Team appreciates this process, which is in line with the WENRA (2014) requirement of continuous improvement, and encourages proceeding with it. It is suggested to base the process on a set of comprehensive national regulatory requirements for external hazards, which should be developed considering the WENRA (2014) Reference Levels. The authors of the document note that in the past, ANPP and ANRA have undertaken continued efforts to ensure and improve the seismic safety of the ANPP. The Peer Review Team appreciates this process, which is in line with the WENRA (2014) requirement of continuous improvement, and encourages proceeding with it. It is suggested to base the process on a set of comprehensive national regulatory requirements for external hazards, which should be developed considering the WENRA (2014) Reference Levels.

In order to increase the safety of the existing NPP the Peer Review Team recommends to develop plans to respond to potential volcanic activity at Ararat, Aragats, and the Shamiram plateau, and to establish a monitoring of these volcanoes in the framework of national civil protection programmes. The authors of the report note that the VVER-440 reactors of ANPP belong to the so- called "Generation I" reactor types. Nevertheless, the reactor type VVER-440 design features leading to a "sedate" operational as well as accidental behavior. The design has some safety merits not found in most other types of PWR in operation.  Large coolant inventory establishes a valuable time buffer for corrective actions in abnormal events, where the balance between residual heat production and coolant supply has been lost. Despite of various programmes of international aid and support, the progress in Severe Accident Management (SAM) programme development and implementation is quite slow and delayed in respect to the original schedules.  Various essential issues are unsolved. In respect to SAM the current level of safety of ANPP is clearly lower than the EU average.  However, this level will increase in near term due to the introduction of Severe Accident Management Guidelines (SAMGs) expected in 2017. Only in the mid-term, with the implementation of the activities pursuant to "Stress Tests" recommendations, ANPP can reach an acceptable level. Therefore the Peer Review Team highly recommends carrying out all planned activities in respect to severe accident management (hardware and procedures/guidelines) as soon as possible. Regarding SAMGs the development and implementation of guidelines for shutdown states and SFP should be initiated and finalized. In respect to hardware modifications especially enhancements of the Emergency Core Cooling System, containment tightness, hydrogen monitoring and control as well as containment spray system should be treated in priority.

To note, following the Fukushima accident in 2011, the EU has been carrying out comprehensive risk and safety assessments (stress tests) of its nuclear power reactors. This Peer review exercise took place in Armenia from the 20th to the 24th June 2016. A team of 10 EU experts (8 from EU Member states which have been nominated by ENSREG members and 2 from the European Commission) was forming the peer review team.