ML041740039

Vermont Nuclear Power Station, Request for Additional Information, Extended Power Uprate. TAC No. MC0761

ML041740039
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	07/06/2004
From:	Richard Ennis NRC/NRR/DLPM/LPD1
To:	Kansler M Entergy Nuclear Operations
Ennis R, NRR/DLPM, 415-1420
References
TAC MC0761
Download: ML041740039 (13)

Text

July 6, 2004 Mr. Michael Kansler President Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION - EXTENDED POWER UPRATE, VERMONT YANKEE NUCLEAR POWER STATION (TAC NO. MC0761)

Dear Mr. Kansler:

By letter dated September 10, 2003, as supplemented on October 1, 2003, October 28, 2003 (2 letters), January 31, 2004 (2 letters), March 4, 2004, and May 19, 2004, Entergy Nuclear Vermont Yankee, LLC and Entergy Nuclear Operations, Inc., submitted a proposed license amendment to the U.S. Nuclear Regulatory Commission (NRC) for the Vermont Yankee-Nuclear Power Station (VYNPS). The proposed amendment, Technical Specification Proposed Change No. 263, Extended Power Uprate would allow an increase in the maximum authorized power level for VYNPS from 1593 megawatts thermal (MWT) to 1912 MWT.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure.

We request that the additional information be provided by July 30, 2004. The response timeframe was discussed with Ms. Ronda Daflucas of your staff on June 30, 2004. If circumstances result in the need to revise your response date, or if you have any questions, please contact me at (301) 415-1420.

Sincerely,

/RA/

Richard B. Ennis, Senior Project Manager, Section VY Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-271

Enclosure:

As stated cc w/encl: See next page

July 6, 2004 Mr. Michael Kansler President Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION - EXTENDED POWER UPRATE, VERMONT YANKEE NUCLEAR POWER STATION (TAC NO. MC0761)

Dear Mr. Kansler:

By letter dated September 10, 2003, as supplemented on October 1, 2003, October 28, 2003 (2 letters), January 31, 2004 (2 letters), March 4, 2004, and May 19, 2004, Entergy Nuclear Vermont Yankee, LLC and Entergy Nuclear Operations, Inc., submitted a proposed license amendment to the U.S. Nuclear Regulatory Commission (NRC) for the Vermont Yankee Nuclear Power Station (VYNPS). The proposed amendment, Technical Specification Proposed Change No. 263, Extended Power Uprate would allow an increase in the maximum authorized power level for VYNPS from 1593 megawatts thermal (MWT) to 1912 MWT.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure.

We request that the additional information be provided by July 30, 2004. The response timeframe was discussed with Ms. Ronda Daflucas of your staff on June 30, 2004. If circumstances result in the need to revise your response date, or if you have any questions, please contact me at (301) 415-1420.

Sincerely,

/RA/

Richard B. Ennis, Senior Project Manager, Section VY Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-271

Enclosure:

As stated cc w/encl: See next page DISTRIBUTION:

PUBLIC TChan, EMCB-B JCai, IROB-B HWalker, SPSB-C PDI-2 Reading RDavis, EMCB-B JBongarra, IROB-B MHart, SPSB-C AHowe LLund, EMCB-C JTappert, RLEP-C FAkstulewicz, SRXB-A REnnis KParczewski, EMCB-C SImboden, RLEP-C EKendrick, SRXB-A AMcMurtray KManoly, EMEB-B JYerokun, SPLB-A CAnderson, RGN I CWu, EMEB-B DReddy, SPLB-A EMarinos, EEIB-A TScarbrough, EMEB-B SWeerakkody, SPLB-B HGarg, EEIB-A DThatcher, IPSB-A RGallucci, SPLB-B RJenkins, EEIB-B RPettis, IPSB-A MRubin, SPSB-A NTrehan, EEIB-B SKlementowicz, IPSB-B MStutzke, SPSB-A MMitchell, EMCB-A RPedersen, IPSB-B RDennig, SPSB-C BElliot, EMCB-A DTrimble, IROB-B RLobel, SPSB-C ACCESSION NO.: ML041740039 OFFICE PDI-VY/PM PDI-VY/SC NAME REnnis AHowe DATE 06/30/04 07/06/04 OFFICIAL RECORD COPY

Vermont Yankee Nuclear Power Station cc:

Regional Administrator, Region I Ms. Carla A. White, RRPT, CHP U. S. Nuclear Regulatory Commission Radiological Health 475 Allendale Road Vermont Department of Health King of Prussia, PA 19406-1415 P.O. Box 70, Drawer #43 108 Cherry Street Mr. David R. Lewis Burlington, VT 05402-0070 Shaw, Pittman, Potts & Trowbridge 2300 N Street, N.W. Mr. James M. DeVincentis Washington, DC 20037-1128 Manager, Licensing Vermont Yankee Nuclear Power Station Ms. Christine S. Salembier, Commissioner P.O. Box 0500 Vermont Department of Public Service 185 Old Ferry Road 112 State Street Brattleboro, VT 05302-0500 Montpelier, VT 05620-2601 Resident Inspector Mr. Michael H. Dworkin, Chairman Vermont Yankee Nuclear Power Station Public Service Board U. S. Nuclear Regulatory Commission State of Vermont P.O. Box 176 112 State Street Vernon, VT 05354 Montpelier, VT 05620-2701 Director, Massachusetts Emergency Chairman, Board of Selectmen Management Agency Town of Vernon ATTN: James Muckerheide P.O. Box 116 400 Worcester Rd.

Vernon, VT 05354-0116 Framingham, MA 01702-5399 Operating Experience Coordinator Jonathan M. Block, Esq.

Vermont Yankee Nuclear Power Station Main Street 320 Governor Hunt Road P.O. Box 566 Vernon, VT 05354 Putney, VT 05346-0566 G. Dana Bisbee, Esq. Mr. John F. McCann Deputy Attorney General Director, Nuclear Safety Assurance 33 Capitol Street Entergy Nuclear Operations, Inc.

Concord, NH 03301-6937 440 Hamilton Avenue White Plains, NY 10601 Chief, Safety Unit Office of the Attorney General Mr. Gary J. Taylor One Ashburton Place, 19th Floor Chief Executive Officer Boston, MA 02108 Entergy Operations 1340 Echelon Parkway Ms. Deborah B. Katz Jackson, MS 39213 Box 83 Shelburne Falls, MA 01370

Vermont Yankee Nuclear Power Station cc:

Mr. John T. Herron Mr. Ronald Toole Sr. VP and Chief Operating Officer 1282 Valley of Lakes Entergy Nuclear Operations, Inc. Box R-10 440 Hamilton Avenue Hazelton, PA 18202 White Plains, NY 10601 Ms. Stacey M. Lousteau Mr. Danny L. Pace Treasury Department Vice President, Engineering Entergy Services, Inc.

Entergy Nuclear Operations, Inc. 639 Loyola Avenue 440 Hamilton Avenue New Orleans, LA 70113 White Plains, NY 10601 Mr. Raymond Shadis Mr. Brian OGrady New England Coalition Vice President, Operations Support Post Office Box 98 Entergy Nuclear Operations, Inc. Edgecomb, ME 04556 440 Hamilton Avenue White Plains, NY 10601 Mr. James P. Matteau Executive Director Mr. Michael J. Colomb Windham Regional Commission Director of Oversight 139 Main Street, Suite 505 Entergy Nuclear Operations, Inc. Brattleboro, VT 05301 440 Hamilton Avenue White Plains, NY 10601 Mr. William K. Sherman Vermont Department of Public Service Mr. John M. Fulton 112 State Street Assistant General Counsel Drawer 20 Entergy Nuclear Operations, Inc. Montpelier, VT 05620-2601 440 Hamilton Avenue White Plains, NY 10601 Mr. Jay K. Thayer Site Vice President Entergy Nuclear Operations, Inc.

Vermont Yankee Nuclear Power Station P.O. Box 0500 185 Old Ferry Road Brattleboro, VT 05302-0500 Mr. Kenneth L. Graesser 38832 N. Ashley Drive Lake Villa, IL 60046 Mr. James Sniezek 5486 Nithsdale Drive Salisbury, MD 21801

REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED LICENSE AMENDMENT EXTENDED POWER UPRATE VERMONT YANKEE NUCLEAR POWER STATION DOCKET NO. 50-271 By letter dated September 10, 2003, as supplemented on October 1, 2003, October 28, 2003 (2 letters), January 31, 2004 (2 letters), March 4, 2004, and May 19, 2004 (References 1 through 8), Entergy Nuclear Vermont Yankee, LLC and Entergy Nuclear Operations, Inc.

(Entergy or the licensee), submitted a proposed license amendment to the U.S. Nuclear Regulatory Commission (NRC) for the Vermont Yankee Nuclear Power Station (VYNPS). The proposed amendment, Technical Specification Proposed Change No. 263, Extended Power Uprate would allow an increase in the maximum authorized power level for VYNPS from 1593 megawatts thermal (MWT) to 1912 MWT.

The NRC staff is reviewing your Extended Power Uprate (EPU) amendment request and has determined that additional information is required to complete the review. The specific information requested is addressed in the following request for additional information (RAI).

Note, the question numbers are a continuation of the numbering used in the RAI issued by the NRC on May 28, 2004.

Enclosure

Plant Systems Branch (SPLB)

Balance of Plant Section (SPLB-A)

Reviewer: Devender Reddy

7. Spent Fuel Pool Cooling and Cleanup System:

(Reference 1, Attachment 6, Section 6.3) a) Spent Fuel Pool (SFP) Cooling Capacity:

Please describe the analyses that were performed and assumptions and input parameters that were used for the proposed EPU to address the following review criteria in NRC Review Standard, RS-001, Attachment 2 to Matrix 5, Supplemental Spent Fuel Pool Cooling Review Criteria, Section 3.1.1.1:

i) heat removal capability is based on bounding estimates of ultimate heat sink temperature, cooling system flow rates, and heat exchanger performance (e.g., fouling and tube plugging).

ii) alternate heat removal paths (e.g., evaporative cooling) should be appropriately validated and based on bounding input parameter values (e.g., air temperature, relative humidity, and ventilation flow rate).

b) Heat Removal Capability and Limiting Case for Core Offload:

Table 6-3 in Attachment 6 to Reference 1 provides five SFP cooling/core offload configurations. Please update this table to include the following configurations discussed in the VYNPS Updated Safety Analysis Report (UFSAR),

Section 10.5.5, page 10.5-9, third paragraph:

i) Limiting Normal Batch (one-third core) Offload: One train (one heat exchanger and one pump) of Standby Fuel Pool Cooling Subsystem (SFPCS) in service, and ii) Limiting Full Core Offload: Both trains (two heat exchangers and two pumps) of SFPCS in service.

Also, discuss the assumptions and input parameters that were used in the analyses for the two additional configurations discussed above and confirm that they are consistent with the existing plant licensing basis and that the worst-case ultimate heat sink temperatures were used.

8. Service Water Systems (SWS):

(Reference 1, Attachment 6, Section 6.4) a) In Section 6.4.1.1 of Attachment 6 to Reference 1, it is stated that:

The performance of the safety-related portion of the SW system during and following the most demanding design basis event, the LOCA, was demonstrated.

Adequate SW system heat transfer capabilities exist at CPPU [constant pressure power uprate] to support the above components. In addition, the SW flow rates do not change.

i) With regard to performance, heat-loads, heat transfer capabilities, flow rates, and flow velocities in the SWS for post CPPU conditions, please explain how the above conclusions were reached.

ii) Also, describe the analyses that have been performed, assumptions, and input parameters that were used; and explain the impact of the proposed EPU on UFSAR Section 10.6.4, Safety Design Bases, Items 1, 2, and 3.

b) Regarding the Residual Heat Removal Service Water (RHRSW) system, in Section 6.4.1.3 of Attachment 6 to Reference 1, it is stated that:

The post-LOCA containment and suppression pool responses have been calculated based on an energy balance between the post-LOCA heat loads and the existing heat removal capacity of the RHR and RHRSW systems. As discussed in 3.5.2 and 4.1.1, the existing suppression pool structure and associated equipment have been reviewed for acceptability based on this increased post-LOCA suppression pool temperature....Thus, the RHRSW system has sufficient capacity to serve as the coolant supply for long-term core and containment cooling as required for CPPU conditions. The RHRSW system flow rate is not changed.

i) With regard to performance, heat-loads, heat transfer capabilities, flow rates, and flow velocities in the RHRSW system for post CPPU conditions, please explain how the above conclusions were reached.

ii) Also, describe the analyses that have been performed, assumptions, and input parameters that were used; and explain the impact of the proposed EPU on the UFSAR Section 10.7.4, Safety Design Bases, Item 1.

c) Confirm that the analyses performed for the proposed EPU are consistent with the existing plant licensing basis and that the worst-case ultimate heat sink temperature was used in calculating flow requirements of the safety-related SWS and the RHRSW systems for the proposed CPPU conditions.

d) Please describe any impacts that the proposed EPU will have on the issues discussed in Generic Letters 89-13, Service Water System Problems Affecting Safety-Related Equipment, 96-06, Assurance of Equipment Operability and Containment Integrity during Design Basis Accident Conditions, and 96-06, Supplement 1, including the basis for your determination. In particular, confirm that water hammer and two-phase flow will not occur in the SWS, RHRSW, and other safety-related cooling water systems due to the EPU. Also, confirm that the power uprate will not result in overpressurization of water-filled piping between containment isolation valves.

9. Ultimate Heat Sink (UHS) / Alternate Cooling System (ACS):

(Reference 1, Attachment 6, Section 6.4.5) a) In Section 6.4.5 of Attachment 6 to Reference 1, it is stated that:

The ACS was evaluated for CPPU in a manner that is similar to the UHS evaluation for newer plants (e.g., inventory requirements and heat removal capability with increased decay heat)....The heat removal requirements of the following affected components during the ACS operating mode have been evaluated and found to be acceptable at CPPU....

i) With regard to performance, heat-loads, heat transfer capabilities, flow rates, and flow velocities in the ACS for post CPPU conditions, please explain how the above conclusions were reached.

ii) Also, describe the analyses that have been performed, assumptions, and input parameters that were used; and explain the impact of the proposed EPU on UFSAR Section 10.8.2, Safety Design Bases, Items 1, 2, and 3.

b) In Reference 5, Attachment 6, MATRIX 5, Page 8, SE 2.5.3.4, it is stated that no SW flow or SW supply temperature changes are required to support the CPPU normal, LOCA or shutdown operations. Please explain.

c) Confirm that the analyses performed for the proposed EPU are consistent with the existing plant licensing basis and that the worst-case ultimate heat sink temperature was used in calculating flow requirements of the ACS for the proposed CPPU conditions.

d) In Reference 1, Attachment 6, Section 6.4.5, as well as in Reference 5, Attachment 6, MATRIX 5, Page 8, SE 2.5.3.4, it is stated that a modification to re-circulate ACS (RHRSW) pump motor cooler water back to the cooling tower, instead of discharging it to the river, is planned to ensure adequate inventory to meet the 7-day requirement associated with the ACS design-basis functional scenario. Please provide a description of the modification, including a flow diagram. In addition, discuss the regulatory requirements applicable to the modification.

Probabilistic Safety Assessment Branch (SPSB)

Containment and Accident Dose Assessment Section (SPSB-C)

Reviewers: Richard Lobel (Containment), Harold Walker (HVAC), Michelle Hart (Dose) 28.* Provide additional information regarding the potential impact of the CPPU on those HVAC systems discussed in the Standard Review Plan sections 6.4, 6.5.1, 9.4.1, 9.4.2, 9.4.3, 9.4.4 and 9.4.5. This should include a discussion of the impact, if any, during both normal and post-accident operations resulting from increases in heat loads due to CPPU and the bases for your determination of system acceptability post-CPPU.

• Note, this question was previously transmitted to the licensee via e-mail on June 3, 2004.

29. Please provide the design basis and realistic values of inputs used in the determination of emergency core cooling system (ECCS) pump available net positive suction head (NPSH) (i.e., the values used in the MAAP probabilistic risk assessment (PRA) calculations and the SHEX calculations). Please include:

a) service water temperature b) initial containment temperature c) initial containment pressure d) initial drywell and wetwell humidity e) initial suppression pool temperature f) drywell and wetwell airspace volume g) suppression pool water volume

30. Please describe how containment leakage is modeled in the design basis NPSH calculations. Is MSIV leakage included? If not, why not?

31. The VYNPS Individual Plant Examination (IPE) report dated December 21, 1993 (Reference letter BVY 93-139), Section 3.1.2.1, Large LOCA Event Tree, Event AI (Alternate Injection), models the failure of long-term core cooling due, in part, to "loss of LP/CS NPSH at high suppression pool temperature if the containment vent opens and the operator fails to control pressure by reclosing the vent." Concerning the accident sequence modeling for large LOCAs, describe all differences between the IPE and the PRA performed to support the EPU application.

32. Please provide input to the computer calculation (data in ASCII format) of the minimum containment accident pressure used for ECCS pump NPSH calculations for the double ended guillotine break of a recirculation line. Please verify that the input is consistent with the VYNPS emergency operating procedures. In addition, provide a schematic of containment with dimensions and ECCS schematic for this analysis . The input parameters needed are included in Attachment 1.

33. Please provide the results of the containment accident pressure calculation used for ECCS pump NPSH calculations. Include:

a) drywell pressure vs. time b) drywell temperature vs. time c) wetwell pressure vs. time d) wetwell air temperature vs. time e) suppression pool temperature vs. time f) suppression pool level vs. time

REFERENCES

1) Entergy letter (BVY 03-80) to NRC dated September 10, 2003, Vermont Yankee Nuclear Power Station, Technical Specification Proposed Change No. 263, Extended Power Uprate

2) Entergy letter (BVY 03-90) to NRC dated October 1, 2003, Vermont Yankee Nuclear Power Station, Technical Specification Proposed Change No. 263, Supplement No. 1, Extended Power Uprate -Technical Review Guidance

3) Entergy letter (BVY 03-95) to NRC dated October 28, 2003, Vermont Yankee Nuclear Power Station, Technical Specification Proposed Change No. 263, Supplement No. 2, Extended Power Uprate - Grid Impact Study

4) Entergy letter (BVY 03-98) to NRC dated October 28, 2003, Vermont Yankee Nuclear Power Station, Technical Specification Proposed Change No. 263, Supplement No. 3, Extended Power Uprate - Updated Information

5) Entergy letter (BVY 04-009) to NRC dated January 31, 2004, Vermont Yankee Nuclear Power Station, Technical Specification Proposed Change No. 263, Supplement No. 4, Extended Power Uprate - NRC Acceptance Review

6) Entergy letter (BVY 04-008) to NRC dated January 31, 2004, Vermont Yankee Nuclear Power Station, Technical Specification Proposed Change No. 263, Supplement No. 5, Extended Power Uprate - Response to Request for Additional Information

7) Entergy letter (BVY 04-025) to NRC dated March 4, 2004, Vermont Yankee Nuclear Power Station, Technical Specification Proposed Change No. 263, Supplement No. 6, Extended Power Uprate - Withholding Proprietary Information

8) Entergy letter (BVY 04-050) to NRC dated May 19, 2004, Vermont Yankee Nuclear Power Station, Technical Specification Proposed Change No. 263, Supplement No. 7, Extended Power Uprate - Confirmatory Results

Attachment 1 Parameters Needed for Question 32 Containment Volume (upper uncertainty range) drywell (including free volume of vents at low suppression pool water level) drywell hold-up volume - i.e., the pool volume prior to falling into the vents wetwell atmosphere (at low suppression pool water level) wetwell suppression pool (including vent water volume at min. level) initial suppression pool depth (minimum) initial suppression pool surface area (at min. depth) vent lengths and diameters from drywell to wetwell (include number of downcomers)

Initial Pressure (minimum) drywell wetwell Initial Temperature (maximum) drywell wetwell Initial Humidity (maximum) drywell wetwell List all structures (heat sinks) by providing the upper uncertainty range for surface area, thickness, material composition, and identify the exposed volume boundary. Include:

- Heat transfer properties (upper range) (including description of coatings, if applicable)

- Consider heat transfer characteristics, e.g., two-sided exposed structures will have half-thickness, the outside boundary of the drywell and torus structures, etc.

Wetwell to Drywell Vacuum Breakers Number Diameter Differential pressure setpoint Opening Time Loss Coefficient Rx Building to Wetwell Vacuum Breakers Number Diameter Differential pressure setpoint Opening Time Loss Coefficient Containment Leakage (upper range)

Drywell to Reactor Building; Area & Loss Coefficient Wetwell to Reactor Building; Area & Loss Coefficient

Drywell Spray performance mass flow vs. time temperature vs. time Initial spray droplet size (smallest)

Wetwell Spray performance mass flow vs. time temperature vs. time Initial spray droplet size (smallest)

Initial RPV water Level (with expected range)

Recirc Line Diameter and Break Area SRV Performance (if applicable)

SRV Discharge flow mass and energy vs. time Number Diameter Differential pressure setpoint Opening time Loss Coefficient Recirc Break flow mass and energy vs. time Decay Heat vs. Time Pump Heat vs. Time ECCS injection flowrates/enthalpy versus time from suppression pool to RPV and/or drywell/wetwell sprays RHR Heat Exchanger Heat Removal Performance (assumed single failure) upper range for heat transfer with lowest service water temperature