ML040860570

Request for Additional Information (Rai), Review of License Amendment Request to Increase the Main Steam Line Turbine Building High Temperature Trip Setpoint Allowable Value

ML040860570
Person / Time
Site:	Perry
Issue date:	03/31/2004
From:	Sands P NRC/NRR/DLPM/LPD3
To:	Kanda W FirstEnergy Nuclear Operating Co
Sands S, 415-3154, NRR/DLPM
References
TAC MC0342
Download: ML040860570 (8)

Text

March 31, 2004 Mr. William R. Kanda, Vice President - Nuclear First Energy Nuclear Operating Company 10 Center Road P.O. Box 97 Perry, OH 44081

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (RAI) FOR THE REVIEW OF LICENSE AMENDMENT REQUEST TO INCREASE THE MAIN STEAM LINE TURBINE BUILDING HIGH TEMPERATURE TRIP SETPOINT ALLOWABLE VALUE AT PERRY NUCLEAR POWER PLANT (TAC. NO. MC0342)

Dear Mr. Kanda:

By letter dated August 14, 2003, First Energy Nuclear Operating Company (FENOC), requested approval of a license amendment for the Perry Nuclear Power Plant (PNPP) to increase the main steam line turbine building high temperature trip setpoint allowable value contained in the Technical Specification (TS) Table 3.3.6.1-1, item 1.f, "Allowable Value of Main Steam Line Turbine Building Temperature-High, function from 138.9EF to 149.6EF.

During the review, the NRC staff has identified that additional information is needed in order to complete the review. Specific questions are presented in the attached request for additional information (RAI).

The enclosed questions have already been discussed with your staff. In order to accommodate PNPPs need for this change before the summer, please respond to this RAI by May 26, 2004.

If you have any questions concerning our review, or additional time is needed to respond to the RAI, please contact me at (301) 415-3154.

Sincerely,

/RA/

Stephen P. Sands, Project Manager, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No.: 50-440

Enclosures:

Request for Additional Information cc w/encl: See next page

March 31, 2004 Mr. William R. Kanda, Vice President - Nuclear First Energy Nuclear Operating Company 10 Center Road P.O. Box 97 Perry, OH 44081

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (RAI) FOR THE REVIEW OF LICENSE AMENDMENT REQUEST TO INCREASE THE MAIN STEAM LINE TURBINE BUILDING HIGH TEMPERATURE TRIP SETPOINT ALLOWABLE VALUE AT PERRY NUCLEAR POWER PLANT (TAC. NO. MC0342)

Dear Mr. Kanda:

By letter dated August 14, 2003, First Energy Nuclear Operating Company (FENOC), requested approval of a license amendment for the Perry Nuclear Power Plant (PNPP) to increase the main steam line turbine building high temperature trip setpoint allowable value contained in the Technical Specification (TS) Table 3.3.6.1-1, item 1.f, "Allowable Value of Main Steam Line Turbine Building Temperature-High, function from 138.9EF to 149.6EF.

During the review, the NRC staff has identified that additional information is needed in order to complete the review. Specific questions are presented in the attached request for additional information (RAI).

The enclosed questions have already been discussed with your staff. In order to accommodate PNPPs need for this change before the summer, please respond to this RAI by May 26, 2004.

If you have any questions concerning our review, or additional time is needed to respond to the RAI, please contact me at (301) 415-3154.

Sincerely,

/RA/

Stephen P. Sands, Project Manager, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No.: 50-440

Enclosures:

Request for Additional Information cc w/encl: See next page DISTRIBUTION:

PUBLIC PDIII-2 R/F AMendiola SSands PCoates OGC ACRS SReynolds, RIII ADAMS Accession Number: ML040860570 OFFICE PM:LPD3-2 LA:LPD3-2 SC:LPD3-2 NAME SSands PCoates DPickett for AMendiola DATE 03/30/04 03/30/04 03/31/04 OFFICIAL RECORD COPY

Perry Nuclear Power Plant, Unit 1 cc:

Mary E. OReilly Carol OClaire, Chief, Radiological Branch FirstEnergy Corporation Ohio Emergency Management Agency 76 South Main St. 2855 West Dublin Granville Road Akron, OH 44308 Columbus, OH 43235-7150 Resident Inspectors Office Mayor, Village of Perry U.S. Nuclear Regulatory Commission P.O. Box 100 P.O. Box 331 Perry, OH 44081-0100 Perry, OH 44081-0331 Dennis Clum Regional Administrator, Region III Radiological Assistance Section Supervisor U.S. Nuclear Regulatory Commission Bureau of Radiation Protection 801 Warrenville Road Ohio Department of Health Lisle, IL 60532-4531 P.O. Box 118 Columbus, OH 43266-0118 Sue Hiatt OCRE Interim Representative Zack A. Clayton 8275 Munson DERR Mentor, OH 44060 Ohio Environmental Protection Agency ATTN: Mr. Zack A. Clayton Mr. Vernon K. Higaki P.O. Box 1049 Manager - Regulatory Affairs Columbus, OH 43266-0149 FirstEnergy Nuclear Operating Company Perry Nuclear Power Plant Chairman P.O. Box 97, A210 Perry Township Board of Trustees 10 Center Road 3750 Center Road, Box 65 Perry, OH 44081 Perry, OH 44081 Timothy Rausch, Plant Manager Daniel Z. Fisher FirstEnergy Nuclear Operating Company Transportation Department Perry Nuclear Power Plant Public Utilities Commission P.O. Box 97, SB306 180 East Broad Street Perry, OH 44081 Columbus, OH 43215-3793 Mayor, Village of North Perry Joseph J. Hagan North Perry Village Hall Senior Vice President 4778 Lockwood Road Engineering and Servicees North Perry Village, OH 44081 First Energy Nuclear Operating Company 76 South Main Street Donna Owens, Director Akron, Ohio 44308 Ohio Department of Commerce Division of Industrial Compliance Bureau of Operations & Maintenance 6606 Tussing Road P. O. Box 4009 Reynoldsburg, OH 43068-9009

REQUEST FOR ADDITIONAL INFORMATION PERRY NUCLEAR POWER PLANT (PNPP)

LICENSE AMENDMENT REQUEST TO INCREASE MAIN STEAM LINE TURBINE BUILDING HIGH TEMPERATURE TRIP SETPOINT ALLOWABLE VALUE CONTAINED IN THE TECHNICAL SPECIFICATIONS The Nuclear Regulatory Commission (NRC) staff has reviewed the August 14, 2004, FENOC submittal regarding changes to the Perry Nuclear Power Plant Technical Specification change.

In order to complete the review of the proposed license amendment request (LAR), the staff needs the following information concerning the GOTHIC analysis used to support the change.

The staff has focused on case W-3-33 (worst case for temperature response for proposed leak rate).

(1) It is stated that the GOTHIC subdivided volume model is used for cases where buoyancy-induced flow is expected to be the primary means of mass transport or, for this case, when the steam line break is small and there exists the possibility of a localized temperature response (CN 2.4.6.14 Rev 0, page 3 of 51). In the GOTHIC qualification manual two studies are presented which appear to be related to this LAR.

One is standard problem 13 which shows thermal stratification for a 3x3 subdivided model, however, the results are not qualified and there is only a single control volume (1,000 ft3). The other is an HDR study which supports the need for consistent vertical modeling, as used in the LAR model, however, the HDR is not on a scale similar to the turbine building. (a) Is there any data or comparisons to other computer programs (for example those used to evaluate building HVAC and contaminate transport) which can be used to assess or confirm the LAR model? (b) Have there been any loss of ventilation events at Perry which could be used to benchmark the model?

(2) A steady-state run, for a period of one hour, is performed before the transient starts.

During this run the steady-state circulation flows are established based on the initial conditions and the modeling (flow paths, heat sinks and sources). During this time period the temperatures in the model decrease, with, for example, the fluid and heat sinks in control volume (CV) 1 reaching about 84.4 EF (starting at 110 EF). While this could be characterized as a conservative aspect of the model, it would take longer to heat up the cooled down fluid and structures, it would appear that the results may be influenced by the nodalization. (a) Are the conditions at the end of the steady-state run the expected conditions at the time of the leak? (Note, for other cases, summer and average, the results are different.) (b) Have nodalization studies, changes in the number of subdivided volumes per control volume and number of control volumes, been performed to support the LAR model? (c) The heat sources and boundary conditions (fixed heat fluxes) should be re-evaluated to provide a better steady-state, or additional justification for the current model is needed.

ENCLOSURE

(3) The intent of the environmental boundary condition, BC 1P, is to maintain the pressure in the lower elevations in the turbine building at near atmospheric pressure, with the area of flow path (FP) 21 set large enough to allow the air to be driven to the outside atmosphere. It would therefore be expected that the various CVs in the model would remain at, or near, about 14.7 psia. However, during the steady-state portion of the transient, the pressure rises to about 15.3 psia. Following the start of the leak the pressure increases to about 15.92 psia, in 14 minutes, and settles down to about 15.8 psia. This could be characterized as non-conservative, it would not take as long to heat up the fluid and structures at the higher pressure. (a) Are the conditions at the end of the steady-state run the expected conditions at the time of the leak? (Note, for other cases, summer and average, the results are different.) (b) FP 21 should be re-evaluated (area, hydraulic diameter) to provide a means to maintain the pressure near atmospheric or the current model needs additional justification.

(4) Based on guidance in the GOTHIC User Guide (for a sharp-edged orifice in a wall that is much larger than the orifice - as discussed in Section 21.6.3 Doorways), a forward and reverse non-recoverable loss coefficient of 2.78 is used in all FPs. It is not clear that FPs with areas on the order of 100 to 900 ft2 would be covered by this guidance. The effective CV areas are on the order of 1,000 to 8,000 ft2, before subdividing into smaller interfaces. Consider FP 5 with an area of 915 ft2, connecting CV 7s12 to CV 6s11. The subdivided volume interface area is about 1,200 ft2 (39 ft by 30.5 ft), with a total side area of 8,050 ft2 (115 ft by 70 ft). The total FP area between CV 7 and CV 6 is over 4,300 ft2. (a) Provide justification for the value used for the loss coefficient, including reference to appropriate data. (b) Have any studies been performed to assess the importance of this assumption? (c) Is the geometry and forced circulation closer to the case where the value should be 1.0?

(5) It appears that only CV 7 includes modeling of X-direction and Y-direction cell face variations, in addition to the Z-direction (elevation). (a) Why is this appropriate, should the other CVs include these variations? (b) What does GOTHIC assume if the information is not provided, is the (default) def value used throughout?

(6) In developing the flow path modeling, it is assumed that the volume-to volume flow velocities are relatively small and a constant flow path inertia length (30 ft) is used for all volume-to-volume connections (FP 23 used 70 ft) and the flow path friction length is set to a small constant value (1.0 ft). It is further stated that the friction length is only important for thermally or buoyancy driven flows and the LAR case is driven by the forced ventilation system (CN 2.4.6.14 Rev 0, page 7 of 51), that is this length is unimportant. It also appears that the hydraulic diameters are assumed to be constant for large or small areas, and that for FPs 15 to 20 they represent some type of flow restriction. (a) Have any studies been performed to assess the importance of these assumptions? (b) Have the results been assessed to verify these assumptions?

(c) Explain the apparent inconsistency between the statements on pages 3 (See (1) above) and 7 of CN 2.4.6.14 Rev 0. (d) Provide the rationale for the selection of the hydraulic diameters and assess their importance.

(7) Scoping studies (attempting to address the above issues) performed by the staff, using GOTHIC 7.0, indicate that there is a large uncertainty in the time to reach the proposed high temperature trip setpoint, ranging from about 8 minutes to 48 minutes to reach 155 EF. The initial and boundary conditions address seasonal changes and are

reasonable. How should uncertainties in developing the model (nodalization, flow path characterization and heat sources/sinks) be considered in establishing the setpoint?

(8) The submittal states that with a leak of 280 gpm, the Main Steam system will isolate in about 17.5 minutes to limit the impact of the leak. The submittal does not discuss leaks of <280 gpm but >25 gpm. The staff is concerned that a lesser but still substantial leak could go undetected for an extended period of time with unanalyzed consequences.

The licensee needs to provide an analysis that addresses the impact of leaks between 25 and 280 gpm.

(9) On page 3 of 7 of the technical analysis, item 3 states that: The leak will be detected before the leakage could increase a level beyond the capability of the makeup system.

What is the approximate leak rate outside containment during normal operation? How much leakage can be compensated by the excess capacity of the feedwater system?

How much CRD flow will also compensate for the leak? The present allowable leakage rate of 25 gpm is made up by the above systems. Please confirm that the proposed 280 gpm leakage rate can be made-up by those systems.

(10) On page 5 of 7-Leakage Shall not Exceed Makeup Capability GE establishes the Loss of Coolant Accident limit as an equivalent 2-inch diameter schedule 80 pipe break based on the normal capability, which is approximately an equivalent mass Main Steam System leakage value of 383 gpm. Please clarify whether 383 gpm is at the upstream or downstream of the break.