{"id":479,"date":"2019-01-12T11:27:27","date_gmt":"2019-01-12T11:27:27","guid":{"rendered":"http:\/\/johnbrear-plantintegrity.com\/?page_id=479"},"modified":"2019-01-12T19:30:48","modified_gmt":"2019-01-12T19:30:48","slug":"defects-in-magnox-gas-circuit-baffles","status":"publish","type":"page","link":"https:\/\/johnbrear-plantintegrity.com\/?page_id=479","title":{"rendered":"Defects in Magnox gas-circuit baffles"},"content":{"rendered":"<figure id=\"attachment_480\" aria-describedby=\"caption-attachment-480\" style=\"width: 482px\" class=\"wp-caption alignright\"><img fetchpriority=\"high\" decoding=\"async\" src=\"http:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Berkeley.jpg\" alt=\"\" width=\"482\" height=\"256\" class=\"size-full wp-image-480\" srcset=\"https:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Berkeley.jpg 4819w, https:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Berkeley-300x159.jpg 300w, https:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Berkeley-768x408.jpg 768w, https:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Berkeley-1024x543.jpg 1024w\" sizes=\"(max-width: 482px) 100vw, 482px\" \/><figcaption id=\"caption-attachment-480\" class=\"wp-caption-text\">Berkeley power station - CEGB photo<\/figcaption><\/figure>\r\n<p>Cracking in the gas circuit expansion baffles of a Magnox nuclear power plant was identified during an inspection.&#160; This portion of the gas circuit is external to the&#160;environmental shielding.<\/p>\r\n<p>The objective of the work was to establish the root cause of cracking and to perform a fitness for service assessment.&#160; A&#160;review of operation and inspection data was followed by the application of Finite Element Analysis (FEA) and Virtual Crack Extension (VCE) procedures to establish rate and direction of crack growth.<\/p>\r\n<p>It was concluded that thermal transients were the prime stress drivers, leading to fatigue.&#160; Crack growth was demonstrated to be relatively slow and the cracks were shown to grow into a thick portion of the baffles where the thermal driving force diminishes.<\/p>\r\n<p>Continued safe operation demonstrated assuming normal conditions prevailed and costly repairs in an irradiated environment were, therefore, avoided.<\/p>","protected":false},"excerpt":{"rendered":"<p>Cracking in the gas circuit expansion baffles of a Magnox nuclear power plant was identified during an inspection.&#160; This portion of the gas circuit is external to the&#160;environmental shielding. The objective of the work was to establish the root cause of cracking and to perform a fitness for service assessment.&#160; A&#160;review of operation and inspection &hellip; <a href=\"https:\/\/johnbrear-plantintegrity.com\/?page_id=479\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Defects in Magnox gas-circuit baffles<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":107,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-479","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages\/479","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=479"}],"version-history":[{"count":4,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages\/479\/revisions"}],"predecessor-version":[{"id":517,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages\/479\/revisions\/517"}],"up":[{"embeddable":true,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages\/107"}],"wp:attachment":[{"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=479"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}