View source for BVY-99-128, Submits Listed Addl Info in Support of 990414 Request for Clarification to SER Confirming Adequacy of Space Cooling for HPCI & RCIC Sys,Re Item II.K.3.24 of NUREG-0737.Copy of NEDE-24955,encl

{{Adams
| number = ML20217C422
| issue date = 10/06/1999
| title = Submits Listed Addl Info in Support of 990414 Request for Clarification to SER Confirming Adequacy of Space Cooling for HPCI & RCIC Sys,Re Item II.K.3.24 of NUREG-0737.Copy of NEDE-24955,encl
| author name = Sen G
| author affiliation = VERMONT YANKEE NUCLEAR POWER CORP.
| addressee name = 
| addressee affiliation = NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
| docket = 05000271
| license number = 
| contact person = 
| case reference number = RTR-NUREG-0737
| document report number = BVY-99-128, NUDOCS 9910130256
| package number = ML20217C427
| document type = CORRESPONDENCE-LETTERS, INCOMING CORRESPONDENCE
| page count = 3
}}

=Text=
{{#Wiki_filter:m VERMONT YANKEE y
* NUCLEAR POWER CORPORATION 185 Old Ferry Road, Brattleboro. VT 05301 7002 (802) 257 5271 October 6,1999 BVY 99-128 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk .
Washington, DC 20555

==References:==
          -(a)      Letter, VYNPC to USNRC," Vermont Yankee Response to NUREG.
0737 Items due on January 1,1982," FVY 82-1, dated January 5,1982.
(b)      Letter, USNRC to VYNPC,"NUREG-0737 Item II.K.3.24, Adequacy of Space Cooling for HPCI and RCIC Systems," NVY 82-180, dated October 29,1982.
(c)      Letter, VYNPC to USNRC," Clarification to SER for NUREG-0737 Item II.K.3.24," BVY 99-51, dated April 14,1999.

==Subject:==
Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)
Sunnlemental Information for Clarification of NUREG-0737 Item II.K.3.24 NUREG-0737, II.K.3.24 states that the Reactor Core Isolation Cooling (RCIC) and High Pressure Coolant Injection (HPCI) systems should be designed to withstand a complete loss of offsite AC
              . power to their support systems, including coolers, for at least 2 hours.
In Reference (b) Vermont Yankee received a Safety Evaluation Report (SER) confirming the
             ' adequacy.of space cooling for our HPCI and RCIC systems. Reference (c) requested a clarification ~of the wording used in Reference (b) to more accurately reflect our installed
              . equipa.ent installation.
Pursuant to a telecon held with your staff on May 13,1999, the following additional information is submitted in support of our requested clarification to the SER.
Vermont Yankee has verified the capability of both the HPCI and RCIC systems to operate for 2 hours with a loss of offsite power by use of the following methods:                                             3 e        NEDE-24955, dated June 1981 determined that the current limiting component for operation of these systems was the Woodward electronic control systems. This equipment was                       ;
determined to have a limitation of 150*F. (copy attached per your request)                             i i
* Analysis and evaluations were performed specifically for NUREG-0737.' The analysis was                 l performed in a conservative manner without taking credit for inherent heat sinks within the            i building. Evaluation of the analysis determined that sufficient heat sinks existed to ensure
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         ,            . that temperature would remain below 150 F.                                                             j 1                                                                                                                      l q
i                                              . M D.13                                                                  C   l 9910130256 991006 PDR P
ADOCK 05000271 PDR 1
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BVY 99-128 /page 2                                             VERMONT YANKEE NUCLEAR POWER CORPORATION i e     Additional analysis for the enveloping conditions of Appendix R and Station Blackout scenarios were subsequently performed. To perform these analyscs a detailed thermal model of each room was constructed and designed to perform steady state and time dependent finite difference analysis of thermal networks. The model consists of a series of nodes representing various pads of each room as well as its surrounding environment. The nodes are interconnected with heat raid, where appropriate, mass flow conductors. Each conductor is sized or designed to allow heat or mass flow to occur at a rate and in a manner that
              - approximates _what will actually occur. A temperature change at any one-node affects heat flow to and from the others. Therefore, a computer code is used to relax the temperatures of each node until a point is reached where the maximum temperature change per iteration is minimal and the energy flow in and out of all nodes is balanced.
Heat loads from equipment, principally the HPCI and RCIC turbines and associated piping were used as basic input to the analyses. The thermal storage capacity of the concrete was also accounted for as well as a differentiation between concrete walls located above and below grade. The analyses assumed an initial temperature of 95 F as a basis for establishing initial thermal equilibrium and temperature gradient across the walls. Specific Heat and Thermal Conductivity properties for air, concrete, rock, and thermal insulation were based on typical industry accepted valces, e     The analyses indicate that the HPCI and RCIC rooms will remain substantially below 150*F.
We believe this letter provides the information discussed in our May 13,1999 telecon to support our request for revision to the SER. Should you have any questions or require additional information, please contact Mr. Jeffrey T. Meyer at (802) 258-4105.
Sincerely, VERMONT YANKEE NUCLEAR POWER CORPORATION
                                                       .              4v1      S
                                                   . dautMn Sen
                                                   - Licensing Manager [
Attachment cc:         USNRC Region 1 Admin:strator-USNRC Project Manager-VYNPS USNRC Resident Inspector-VYNPS Vermont Department of Public Service

==SUMMARY==
OF VERMONT YANKEE COMMITMENTS BVY NO.: BVY 99128 The h3itowing table identifies commitments made in this document by Vermont Yankee, Any other actions discussed in the submittal represent intended or planned actions by Vermont Yankee. They are described to the NRC for the NRC's information and are not regulatory commitments. Please notify the Licensing         !
Manager of any questions regarding this document or any associated commitments.
COMMITMENT                                        COMMITTED DATE OR " OUTAGE" None VYAPF 0058.04 (Sample)
AP 0058 Original                 l Page1of1 1}}