{"id":15691,"date":"2017-10-21T14:06:57","date_gmt":"2017-10-21T14:06:57","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=15691"},"modified":"2022-11-01T10:47:53","modified_gmt":"2022-11-01T10:47:53","slug":"fuel-loading-pattern","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/fuel-loading-pattern\/","title":{"rendered":"Fuel Loading Pattern"},"content":{"rendered":"
The reactor core (PWR type) contains about\u00a0157 fuel assemblies<\/strong> (depending on a reactor type), which are loaded into the core according to a predefined loading pattern.<\/strong><\/div><\/div>\n

The key feature of LWRs fuel cycles<\/strong> is that there are many fuel assemblies<\/strong> in the core. These assemblies have different multiplying properties<\/strong>\u00a0because they may have different enrichment<\/strong> and different burnup<\/strong>. Generally, a common fuel assembly contains energy for approximately 4 years of operation at full power<\/strong>. Once loaded, the fuel stays in the core for 4 years, depending on the design of the operating cycle. During these 4 years, the reactor core has to be refueled. During refueling, every 12 to 18 months, some of the fuel \u2013 usually one-third or one-quarter of the core<\/strong> \u2013 is removed to the spent fuel pool<\/strong>. At the same time, the remainder is rearranged to a location in the core better suited to its remaining level of enrichment. The removed fuel (one-third or one-quarter of the core, i.e., 40 assemblies) must be replaced by fresh fuel assemblies<\/strong>.<\/p>\n

\"Power<\/a>
In commercial reactor cores, the flux distribution is significantly influenced by many factors. There is no cosine and J0 in the commercial power reactor at power operation.<\/figcaption><\/figure>\n

Many different loading patterns have been considered, with the general conclusion that more energy is extracted from the fuel when the power distribution in the core is as flat as possible. In principle, these loading strategies may be divided into two categories:<\/p>\n