3-1-2013 Letter from VY to NRC Plan for Reliable ... - State of Vermont

AREVA NP Inc. ANP-3203Revision 0Vermont Yankee Nuclear Power Station’s Overall Integrated Plan in Response to March 12, 2012Commission Order Modifying Licenses with Regard to Requirements for Reliable HardenedContainment Vents (Order Number EA-12-050)Page 22Section 4: Appilcable Quality RequirementsRequirement 2.1- Containment Isolation FunctionThe HCVS system design shall not preclude the containment isolation valves, Including the vent valve fromperforming their intended containment isolation function consistent with the design basis for the plant Theseitems include piping, piping supports, containment isolation valves, containment isolation valve actuatorsand containment isolation valve position indication componentsISG 2.1 Criteria:The HCVS vent path up to and including the second containment isolation barrier shall be designedconsistent with the design basis of the plant These items include piping. piping supports, containmentisolation valves containment isolation valve actuators and containment isolation valve position indicationcomponents The HCVS design, out to and including the second containment isolation bamer shall meetsafety-related requirements consistent with the design basis of the plant The staff notes that in response toGL 89-16, in many cases. the HCVS vent tine connections were made to existing systems. In some cases.the connection was made in between two existing containment isolation valves and in others to the vacuumbreaker line The HCVS system design shall not preclude the containment isolation valves, including thevent valve from performing their intended containment isolation function consistent with the design basis forthe plant. The design shall include all necessary overrides of containment isolation signals and otherinterface system signals to enable the vent valves to open upon initiation of the HCVS from its control panelResponse (ref. ISG Item 2.1):The HCVS vent path up to and including the second containment isolation piping and supportsis designed in accordance with existing design basis. The HCVS system design will notpreclude the containment isolation valves, including the vent valve, from performing theirintended containment isolation function consistent with the design basis for the plant.Associated actuators, position indication, and power supplies are designed consistent with thedesign basis of the plant as required to maintain their design basis function of maintaining thevalves closed. The control circuit will allow operation of the HCVS from its control panelregardless of containment isolation signals.Requirement 2.2 -Reliableand Rugged PerformanceAll other HCVS components shall be designed for reliable and rugged performance that is capable ofensuring HCVS functionality following a seismic event. These items include electncal power supply, valveactuator pneumatic supply, and instrumentation (local and remote) componentsISG 2.2 Criteria:All components of the HCVS beyond the second containment isolation barrier shall be designed to ensureHCVS functionality following the plants design basis seismic event These components include, in additionto the hardened vent pipe, electric power supply. pneumatic suppfr and instrumentation The design ofpower and pneumatic supply lines between the HCVS valves and remote locations (if portable sources wereto be employed) shall also be designed to ensure HCVS functionality Licensees shall ensure that the HCVSwill not impact other safety-related structures and components and that the HCVS will not be impacted bynon-seismic components. The staff prefers that the HCVS components, includuig the piping run, be locatedin seismically qualified stivctures. However, short runs of HCVS piping in non-seismic structures areacceptable if the licensee provides adequate justification on the seismic ruggedness of these structures Thehardened vent shall be designed to conform to the requirements consistent with the applicable design codesfor the plant, such as the American Society of Mechanical Engineers Boiler and Pressure Vessel Code andthe applicable Specifications, Codes and Standards of the American Institute of Steel Construction.