Status of the Review of Electric Items in Spain Related to the Post-Fukushima Stress Test Programme

Spain Authorities has established a comprehensive compilation of the actions currently related to the post-Fukushima program. It has been initiated both at national and international level and it is developed in an Action Plan. This Plan is aligned to the 6 topics identified in the August 2012 CNS-EOM report, and organized in four parts. One of these parts is related to the loss of electrical power and with a clear objective in implemented new features on increase robustness. This program has been reinforced and the task of Electric Issues has been incremented as a consequence of this Plan. The normal tasks of the Electric Systems and I and C Branch will be presented with the Fukushima related issues as well. The Consejo de Seguridad Nuclear -CSN-(Nuclear Safety Council) maintains a permanent program of control and surveillance of nuclear safety issues in Spanish Nuclear Power Plants. The Electric Systems and I and C Branch of the CSN have different tasks related Electric Issues: - Inspection, control and evaluation of different topics in normal and accidents operation. - Surveillance Testing Inspections. - Design Modifications Inspections and evaluation. - Reactive inspections - Other activities: Participation in Escered project (a before Fukushima Accident) with an objective of analyzed exterior grid stability and check that electric faults in the NPPs vicinity did not cause the simultaneous loss of the offsite supplies fault effects with interaction in inner related systems. Other task related with the management of aging and long-term operation. Now, as a consequence, it has been incremented its task with some new Fukushima related topics: - Analysis of beyond accident related with U.S. SBO Rule (Reg. Guide 1.155) is a part of the design bases for the Spanish plants designed by Westinghouse/ General Electric; switchyard/grid events and extreme weather events are considered, with 10 minutes to connect an alternate source (if provided; if not, use of d.c. supplied systems is foreseen); possibility of SBO affecting to more than one unit simultaneously at the same site is not considered.? Analysis of beyond accident related German standards that have been applied to Trillo plant; in particular, batteries were replaced to reach two hours autonomy. This plant has secondary feed and bleed capability (diesel pump); during 2013 will implement primary bleed and feed capability - ENSREG Specifications. Electric issues assigned to Topic 2 (with Topic 1-external events- inputs); extended SBO, to all the units in the site; 24/72 hours criteria. - Preliminary NPP reports; preliminary CSN report; final NPP reports; final CSN report (Spanish report). Actions proposed by NPPs were considered acceptable, and were completed with some additional requirements. - Management 2012: questions/answers round between the European countries. Evaluations in Luxembourg. Topical reports, integrated into the country reports. Peer review inspections, that involved two Spanish NPPs. - Also during 2012 (in March), CSN issued plant specific Fukushima orders (called ITC-3 instructions). Actions, to be performed in three stages (end of 2012, end of 2014, end of 2016). - The branch has inspected, during 2011, 2012 and 2013, all the NPPs; in particular, Fukushima selected electric issues. Most important findings and experience shall be shown. - Also in 2012, CSN issued orders (called ITC-2, ITC-4), related to great areas damages. This presentation has the objective of describing the current status of the Plan related with Electric Topics in Spanish NPP, and new issues implemented. Additionally, we shall relate the lessons learned of new test and systems implemented in NPP and recent provisions of future actions related to increase on safety and robustness of Electric Systems. (authors)