Superior Safety for Next Generation HTR [Dec 2011]

December 22, 2011 10:24 am

SCHOTT to supply first hermetic glass-to-metal sealed Electrical Penetration Assemblies to China’s first commercial High Temperature Reactor (HTR)
Many of the world’s largest energy consuming countries have been trying to develop their independence in energy generation through scientific and technological advancements, with an emphasis to employ safe and environment-friendly energy generation operations. The latest acquisition by China of SCHOTT’s glass-to-metal sealed Electrical Penetration Assemblies (EPAs) for its first commercial High Temperature Reactor (HTR) has set an example in this direction. These hermetic feedthroughs offer to countries like China, the safest and most reliable EPA technology available today, for their construction of the most modern nuclear power plants in the world.
As part of the arrangement, SCHOTT – an international technology group from Germany, recently delivered the first feedthrough to the Institute of Nuclear and New Energy Technology (INET) at Tsinghua University for testing and training purposes. A demonstration plant is currently under construction at Shidaowan, in the Shandong province of China. China, which has been described as the leading centre for new nuclear reactor designs, has thus conveyed the need for induction of promising technologies into the nuclear power industry for ensuring safety. The high temperature reactor with pebble bed modules (HTR-PM), for example, is considered to be one of the most promising next-generation reactors with its inherent safety features.
Highlighting the performance of glass-to-metal sealing technology from SCHOTT, Xu Yuanhui, Deputy General Manager of Chinergy – a joint venture of the state-owned China Nuclear Engineering and Tsinghua Holding Co. Said, “Based on our investigations and comparisons, EPAs from SCHOTT can meet the high requirements for precision and quality of high temperature reactors. This is why we chose them over many other suppliers for the demonstrator reactor. In addition, SCHOTT has an extremely good reputation and is a reliable supplier. This is of great importance to our HTR project. The successful completion of the demonstration of the HTR plant would pave the way for future nuclear reactor modules.” 
Though many issues have been raised world over about the safety aspects of nuclear power plants, it has been becoming imperative to tackle the issue through induction of the best-in-class critical technologies like that of SCHOTT’s. The importance of such precision technology from SCHOTT can be gauged against the backdrop of certain crisis the world witnessed in recent times.
Fukushima underlined the imperative of safety The Fukushima disaster led the world to take note of safety issues related to nuclear power plants. TEPCO, the operator of the facility in Fukushima, has recently reconstructed the natural catastrophe that led to a breakdown of all available power supplies for the boiling water reactor’s cooling system. TEPCO’s analysis shows that the temperature inside the containment structure must have risen from a normal operating temperature of approximately 60 degrees Celsius to above 250 degrees Celsius while the design pressure was exceeded by more than twofold. The extreme temperature and pressure levels seemed to have overstrained the epoxy seals of the electrical penetrations at the Fukushima facility which are suspected to have led to the leakage of explosive hydrogen, according to TEPCO.Next generation High Temperature Reactor is going through extensive testing phases“The conditions inside the HTR are very demanding. The pressure in the nuclear reactor is about 80 bar and the temperature of the coolant can climb to as high as 1000 degrees Celsius. The temperature is already around 150 degrees Celsius even along the inside wall of the reactor pressure vessel,” Professor Zhou Huizhong from the Institute of Nuclear and New Energy Technology (INET) at Tsinghua University explains. “SCHOTT’s unique expertise in the area of glass-to-metal sealing, particularly in the nuclear industry, convinced us that this is the right technology for our advanced nuclear design.”
“Our standard glass-to-metal sealed penetrations are able to comfortably withstand temperatures in the range of -200 to +240 degrees Celsius. Special material combinations can even tolerate up to 1000 degrees Celsius for a period of time”, says Dr. Oliver Fritz, Head of Technology for the Nuclear Safety Division at SCHOTT Electronic Packaging. “As latest tests have shown, our EPAs remain completely airtight even at pressure peaks above 100 bar – it is the safest and most reliable sealing technology for EPAs available today.”
When, globally, safety issues of nuclear power plants are being discussed in a big way, reliable technologies like that of SCHOTT play a pivotal role in assuring safety.
India has in place ambitious plans to expand its installed nuclear capacity from the current 4780 MWe to 20,000 MWe by 2020. This includes the installation of large water cooled reactors planned under international civil nuclear cooperation with countries such as Russia, France and the US. There are 7 reactors under construction and India is planning to launch at least 6 more Pressurised Heavy Water Reactor (PHWR), 2 Fast Breeder Reactors (FBR) and one Advanced Heavy Water Reactor (AHWR) for which detailed engineering design has been initiated.