HNP-11-094, Response to Request for Additional Information Regarding Measurement Uncertainty Recapture Power Uprate (RAI 8)

Response to Request for Additional Information Regarding Measurement Uncertainty Recapture Power Uprate (RAI #8)

ML11299A023
Person / Time
Site:	Harris
Issue date:	10/20/2011
From:	Jefferson W Progress Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
HNP-11-094
Download: ML11299A023 (9)

Text

10 CFR 50.90

~j Progress Energy OCT 2 02011 HNP- 11-094 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-400 / RENEWED LICENSE NO. NPF-63

Subject:

REQUEST FOR LICENSE AMENDMENT MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION #8

References:

1. Letter from C. L. Burton (PEC) to the U.S. NRC, "Request for License Amendment, Measurement Uncertainty Recapture Power Uprate," dated April 28, 2011.

2. Letter from B. Mozafari (U.S NRC) to W. Jefferson Jr. (PEC), "Shearon Harris Nuclear Plant, Unit 1 - Request for Additional Information Regarding Measurement Uncertainty Recapture Power Uprate (TAC NO. ME6169)"

dated October 14, 2011 (RAI #8).

Ladies and Gentlemen:

In Reference 1, Carolina Power & Light Company (CP&L), doing business as Progress Energy Carolinas, Inc. (PEC), requested changes to the Technical Specifications (TS), Appendix A of Renewed Operating License No. NPF-63, for the Shearon Harris Nuclear Power Plant, Unit No.

1 (HNP). The proposed changes would modify the HNP TS to increase the rated thermal power (RTP) level from 2900 megawatts thermal (MWt) to 2948 MWt, and make Technical Specification changes as necessary to support operation at the uprated power level. The proposed change is an increase in RTP of approximately 1.66 percent. The proposed uprate is characterized as a measurement uncertainty recapture using the Cameron Leading Edge Flow Meter CheckPlus System to improve plant calorimetric heat balance measurement accuracy.

In Reference 2, the USNRC issued a request for additional information (RAI). The enclosure to this letter contains HNP's response to that RAI (#8).

CP&L has concluded that the information provided in this response meets the intent of the original submittal (Reference 1) and does not impact the conclusions of the: 1) Technical Analysis, 2) No Significant Hazards Consideration under the standards set forth in 10 CFR 50.92(c), or 3) Environmental Consideration as provided in the original submittal.

Progress Energy Carolinas, Inc.

Hams Nuclt r r F 0 Boxl"" P b NevwHill N! /i, 2*

U.S. Nuclear Regulatory Commission Page 2 HNP-1 1-094 In accordance with 10 CFR 50.91(b), HNP is providing the state of North Carolina with a copy of this response.

This document contains no new Regulatory Commitments.

Please refer any questions regarding this submittal to Mr. David Corlett, Supervisor - HNP Licensing/Regulatory Programs, at (919) 362-3137.

I declare under penalty of perjury that the foregoing is true and correct. Executed on [ io/0 O.

Sincerely, Vice-President Harris Nuclear Plant

Enclosure:

Response to Request for Additional Information Regarding Measurement Uncertainty Recapture Power Uprate (RAI #8) cc: Regional Administrator, USNRC/Region II Project Manager, Harris Nuclear Plant, USNRC/NRR Resident Inspector, Harris Nuclear Plant, USNRC Section Chief, NC Division of Environmental Health

HNP- 11-094 Enclosure SHEARON HARRIS NUCLEAR POWER PLANT / UNIT NO. 1 (HNP)

DOCKET NO. 50-400 / RENEWED LICENSE NO. NPF-63 LICENSE AMENDMENT REQUEST MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE TAC ME6169 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE (RAI #8)

HNP-1 1-094 Page 2 of 7 Enclosure Question 1 In response to the staff s RAI number 9, the licensee stated in the last paragraph that the existing isophase bus will require increased cooling to accommodate the increase in Megawatt Electric (MWe). The licensee further stated that the plant will implement a modification to the isophase bus duct cooling during the planned spring 2012 refueling.

Provide the proposed isophase bus duct ampere rating at the increased cooling, and demonstrate that the rating is adequate for the increased MWe and Mega Volt Ampere Reactive at MUR power uprate conditions (corresponding to 1136.5 Mega Volt Ampere at 0.9547 power factor as provided in response [to] the staff's RAI number 4).

Response 1 The proposed isophase bus duct ampere rating with increased cooling is 30,310 Amperes, which is the nameplate rating of the main generator at 1155 Mega Volt Amperes (MVA). The isophase bus duct current at the MUR power uprate condition of 1136.5 MVA is 29,825 Amperes (1136.5 MVA/(22 KV**13) = 29,825 Amperes). The proposed isophase bus duct ampere rating is greater than the MUR power uprate current; therefore, the isophase bus duct is adequate for the MUR power uprate conditions.

HNP- 11-094 Page 3 of 7 Enclosure Question 2 In response to the staff's RAI number 2, the licensee stated that a software error was found that could result in an increase in the containment pressure and temperature for the loss-of-coolant accident (LOCA), and that the environmental qualification (EQ) evaluations have been performed to show that the EQ program's existing test limits provide sufficient margin to address the increases that result from correcting mass and energy releases for the LOCA conditions.

Provide containment pressure and temperature profiles for the LOCA conditions before and after incorporation of the corrections necessary due [to] the software error. Also, superimpose the bounding equipment EQ profiles to demonstrate adequate margin continues to exist.

Response 2 The containment composite LOCA/MSLB (main steam line break) temperature profile is provided as Figure CB-1. The heavy black line represents the profile prior to the impact of the EPITOME error, and the tan line on step 5 represents the increase due to the EPITOME error.

The containment composite LOCA/MSLB pressure profile is provided as Figure CB-2. The heavy black line represents the profile prior to the impact of the EPITOME error, and the tan line on step 7 represents the increase due to the EPITOME error.

HNP- 11-094 Page 4 of 7 Enclosure 400 4

350 300 o*" 250 E 200 I-150 100 50 LL 1.OE+00 1.OE+01 1.OE+02 1.OE+03 1.OE+04 1.OE+05 1.OE+06 1.OE+07 1.0E+08 Time (sec.)

-Combined LOCANMSLB Profile - MSLB Profile - LOCA Profile -EPITOME Correction Figure CB-1 Containment Composite LOCA/MSLB Temperature Profile

HNP-1 1-094 Page 5 of 7 Enclosure 70 60 50 240 U) 30 20 10 1.0E+00 1.OE+01 1.0E+02 1.OE+03 1.OE+04 1.OE+05 1,0E+06 1.OE+07 1.OE+08 Time (sec.)

- Combined LOCA/MSLB Profile

-EPITOME Correction Figure CB-2 Containment Composite LOCA/MSLB Pressure Profile

HNP-1 1-094 Page 6 of 7 Enclosure HNP does not develop a bounding profile for all components in a format that provides for ready comparison to the overall limits in a graphical representation. Instead, the test data for each component type is evaluated against the limiting plant profile using acceptance criteria that meets 10CFR50.49. Specific equipment test temperature/pressure profiles are typically available only in paper/pdf format. As a result, the request for the superimposed equipment bounding profile is a challenge. As an alternative response to the request for superimposed curves, the following describes the process used in the HNP EQ program, the impact of the EPITOME error, and sample results demonstrating EQ requirements are satisfied with respect to the MUR Power Uprate.

The HNP EQ process evaluates margin for peak temperature and pressure, and an overall margin identified as equipment's post-accident operability period for each component type. IEEE Standard 323-1974 establishes the HNP EQ Program acceptance criteria:

" Peak temperature: > 15'F or an additional transient with comparable peak, and

• Peak pressure: 10% above gauge

" Equipment Operating Time: 10%

The current bounding peak temperature limit is based on the Main Steam Line Break, which is not affected by the EPITOME errors. Existing peak temperatures and pressures remain applicable, and there are no EQ peak temperature or pressure impacts from the double-ended pump suction accident LOCA scenario.

The EPITOME error does affect the Equipment Operating Time, due to the integrated impact of time at temperature. This is often referred to as an Arrhenius equivalency analysis. Equipment Operating Time margin is determined by comparing plant profiles to individual equipment test profiles using the equipment's minimum activation energy to normalize the data. Changes to existing margin for affected components inside containment were calculated and results evaluated to confirm Equipment Operating Time margin continues to exceed 10% after the temperature profile is corrected. Sample results of the analyses are provided in the table below.

As an example, for the Target Rock Solenoid Operated Valve (SOV), the pre-existing test data has 147% margin, so the impact of the error of 1.65%, normalized using activation energy, does not challenge the 10% acceptance criterion.

Existing Test Data EODP Equipment Description Ea Increase Figure/Margin Figure/Margin 0301 Target Rock SOV 0.81 1.65% 3 147% 4 817.8%

1.04 8.00% 1 494%

0302 ASCO SOV 1 6.23% 1 49%

0.94 4.18% 1 .264%

Limitorque 1.02 7.07% 1.6 574.2% 1.7 927.1%

0303 1.53 27.45% 1.8 24598.2%

0303B Flamtrol 600V Control Cable 1.36 27.44% 3 2315%

0315 ASCO SOV 0.94 4.18% 5 701%

HNP- 11-094 Page 7 of 7 Enclosure Question 3 In response to the staff's RAI Number 2, under the discussion of Radiation Environments to support Equipment Qualification, Accident and Normal Conditions, the licensee stated that the normal operation doses inside the containment reflects the increase in specific activity of N-16 and are based on a core power level of 2900 MWt, averaged over the 60-year plant life.

Describe the relationship between the rise in core power level and the rise in N-16 concentration. Also, describe the relationship between N- 16 concentration and the normal operation radiation level considered for the qualification of electrical equipment inside containment.

Response 3 N-16 is produced as the oxygen of the water coolant is exposed to the fast neutron flux present in the reactor core. The amount of activation is defined by the fast flux level (or power density) of the core, and the amount of time that the coolant is resident in the core. After the coolant exits the core, the N-16 decays.

With the core power increase associated with the MUR, core power level and the fast neutron flux is expected to increase by approximately 1.7 percent. The coolant residence time in the core and the transit time are not expected to change significantly. Therefore, subsequent to the MUR, the normal operation dose rate inside containment in areas influenced by N-16 will increase by approximately 1.7 percent.

Power uprate will nominally increase the radioactivity level in the core by the percentage of the uprate, and the radiation source terms will increase accordingly. Therefore, subsequent to the MUR, the normal operation dose rate contributions from core radioactivity level will also increase by approximately 1.7 percent. Additional factors affecting equilibrium values for dose rates from core radioactivity include fuel enrichment and power history.