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

More documents

Recommendations

Info

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 Rehable HardenedContainment Vents (Order Number EA-12-O50)Section 1: System DescriptionISG Criteria:Pace 3Licensees shall provide a complete description of the system, including important operationalResponse;characteristics. The level of detail generally considered adequate is consistent with the level of detailcontained in the licensees Final Safety Analysis Report.System Overview:The reliable Hardened Containment Vent System (HCVS) will be designed to mitigate loss-ofdecay-heatremoval by providing sufficient containment venting capability to limit containmentpressurization and maintain core cooling capability. The vent will be designed with sufficientcapacity to accommodate decay heat input equivalent to 19.12 MWt, which is 1% of currentlicensed thermal power (CLTP), A venting capacity sized under conditions of constant heat inputat a rate lower than 1 percent of thermal power, if required, will be justified by analysis thatprimary containment design pressure and the Primary Containment Pressure Limit (PCPL)would not be exceeded. Thus, the hardened vent capacity will be adequate to relieve decayheat for a prolonged station blackout (SBO) event. The HCVS is intended for use as oneelement of core damage prevention strategies.The HCVS flow path from the containment to an elevated release point is shown in thesimplified diagram (Figure 1) below. No ductwork will be used in the flow path.Vermont Yankee UFSAR section 2.3.6.3 states: “The “Index of Tornado Damage Potential”(defined in units of 1 000ths of 1% residential property values per year) for the tn-county area is1 as compared to a value of 33 in “tornado alley” (Oklahoma-Kansas-Nebraska).Thom divides the United States into 1-degree squares and determines the tornado frequency foreach square. Using data from 1953-62, Thom records 12 tornadoes occurring within a 1-degreesquare (about 3 million acres) encompassing the Vernon site. A mean recurrence interval for atornado striking a point within this 1 -degree square was calculated to be 1040 years.This seems reasonable if one considers that only 12 tornadoes were reported in about 3 millionacres in a 10-year period.Vermont Yankee UFSAR section 12.2.1 states: “The maximum anticipated wind velocity that isanticipated at the site is 80 mph with gusts to 100 mph... The site is located in a geographicarea which has a small probability of being subjected to tornadic wind conditions”.Vermont Yankee UFSAR section 12.2.1 lis the class I structures that have been designed towithstand short-term tornado winds up to 300 mph. The plant stack is a Class I structure but notlisted to withstand short-term tornado winds.
.--AREVA NP Inc. ANP-3203Revision 0Vermont Yankee Nuclear Power StatioWs Overall Integrated Plan in Response to March 12, 2012Commission Order Modifying Licenses with Regard to Requirements for Reliable HardenedContainment Vents (Order Number EA-12-O50)Paoe 4Figure 1: Simplified Vent Line Connections to Wetwell and Other Systems-./-///-./•STACK/ //New CIV2New CIV1SGT SGT78.*0 *0-38 -3*Th -WfEL -Standby GasTreatmentSystemEquipment and components:The following equipment and components will be provided:i. HCVS Mechanical Components —a) Containment isolation piping, valves and controls - The HCVS vent piping andsupports up to and induding the second containment isolation will be designed in
Page 1 and 2: — EntergyEntergy Nuclear Operatio
Page 3 and 4: SVY 13-016Page 3 of 3NRC Senior Res
Page 5 and 6: Copyright © 2013AREVA NP Inc.All R
Page 7 and 8: AREVA NP Inc. ANP-3203Revision 0Ver
Page 9: AREVA NP Inc. ANP-3203Revision 0Ver
Page 13 and 14: AREVA NP Inc.ANP-3203Revision 0Verm
Page 15 and 16: AREVA NP ANP-3203Revision 0Vermont
Page 35: AREVA NP inc. ANP-3203Revision 0Ver

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

Create successful ePaper yourself

Delete template?

Save as template?