2CAN070902, Response to Request for Additional Information for the Technical Specification Change to Modify RCS Flow Verification

Response to Request for Additional Information for the Technical Specification Change to Modify RCS Flow Verification

ML092050631
Person / Time
Site:	Arkansas Nuclear
Issue date:	07/14/2009
From:	Berryman B Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
2CAN070902
Download: ML092050631 (24)

Text

2CAN070902 July 14, 2009 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Response to Request for Additional Information for the Technical Specification Change to Modify RCS Flow Verification Arkansas Nuclear One, Unit 2 Docket No. 50-368 License No. NPF-6

REFERENCES:

1. Entergy Letter to NRC dated November 13, 2008, License Amendment Request Technical Specification Change to Modify RCS Flow Verification (2CAN110801)

2. Entergy Letter to NRC dated June 1, 2009, Response to Request for Additional Information for the Technical Specification Change to Modify RCS Flow Verification (2CAN060901)

3. Email from Kaly Kalyanam (NRC) to Robert W. Clark (Entergy),

Second Round of RAIs for ME0125, dated June 9, 2009

Dear Sir or Madam:

In Reference 1, Entergy Operations, Inc. (Entergy) proposed a change to the Arkansas Nuclear One, Unit 2 (ANO-2) Technical Specifications (TS). In particular, the change would modify TS 3.3.1.1, Reactor Protective Instrumentation, specifically Table 4.3-1 and associated Notes 7 and 8, to clarify and streamline Reactor Coolant System (RCS) flow verification requirements associated with the Departure from Nucleate Boiling Ratio (DNBR) reactor trip signal. The proposed change allows a more accurate Reactor Coolant Pump (RCP) differential pressure based flow indication, as calculated by the Core Operating Limits Supervisory System (COLSS), to be used as the calibration standard at all surveillance intervals.

During the submittal review process, the Nuclear Regulatory Commission (NRC) determined that additional information was required to complete the review of the Entergy request. The first set of Request for Additional Information (RAI) was electronically transmitted to Entergy.

The response to the RAI was provided via Reference 2. Based on the review of Reference 2, the NRC electronically issued an additional set of RAIs to ANO-2 (Reference 3). The requested due date for the response to this set of RAIs is July 20, 2009.

Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-7721 Brad L. Berryman Acting - Vice President, Operations Arkansas Nuclear One

2CAN070902 Page 2 of 2 The response to the second set of RAIs is included in the attachment to this letter.

This letter contains no new commitments.

If you have any questions or require additional information, please contact David Bice at (479)-858-5338.

I declare under penalty of perjury that the foregoing is true and correct. Executed on July 14, 2009.

Sincerely, Original signed by Brad Berryman Acting VP for Kevin Walsh BLB/rwc

Attachment:

Response to Request for Additional Information cc:

Mr. Elmo E. Collins Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Mr. Kaly Kalyanam MS O-8B1 One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. Bernard R. Bevill Arkansas Department of Health Radiation Control Section 4815 West Markham Street Slot #30 Little Rock, AR 72205

Attachment to 2CAN070902 Response to Request for Additional Information

Attachment to 2CAN070902 Page 1 of 21 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION By letter dated November 13, 2008, Entergy Operations, Inc. (Entergy) proposed a change to the Arkansas Nuclear One, Unit 2 (ANO-2) Technical Specifications (TS). In particular, the change would modify TS 3.3.1.1, Reactor Protective Instrumentation, specifically Table 4.3-1 and associated Notes 7 and 8, to clarify and streamline Reactor Coolant System (RCS) flow verification requirements associated with the Departure from Nucleate Boiling Ratio (DNBR) reactor trip signal.

The proposed change allows a more accurate and precise Reactor Coolant Pump (RCP) differential pressure based flow indication, as calculated by the Core Operating Limits Supervisory System (COLSS), to be used as the calibration standard at all surveillance intervals.

The NRC staff has reviewed the November 13, 2008, request and the response to the first set of Request for Additional Information (RAI). The NRC has determined that additional information is required to complete their review. Each portion of the RAI is listed below.

1. Paragraph 4 of the RAI 1(b) response stated that [a]s part of the analyses performed to support the proposed change, surveillance criteria have been established to ensure calibration errors or instrumentation problems are detected and addressed. Sensitivity analyses have been performed to establish penalties for instrument deviations that will ensure a conservative pump P flow rate.

Discuss the surveillance criteria and the sensitivity analyses used in support of the proposed TS changes.

The surveillance criteria to be used for detection and addressing of calibration errors and instrumentation problems, including the associated sensitivities, were developed within the uncertainty analysis for the proposed change. This analysis is proprietary to Westinghouse and available for review by the NRC at the Westinghouse Rockville, MD office July 20 and 21, 2009.

The criteria will be incorporated into plant surveillance procedures during implementation of the proposed change, if approved, in accordance with the requirements of the Entergy fleet TS implementation process.

The surveillance criteria consist of the following for pump P instruments:

Verification that instrument quality indicated by the plant computer remains acceptable.

Unacceptable or questionable instrument quality is monitored by COLSS cross checks of preferred and alternate instruments.

The pump differential pressure (P) instrumentation for each cold leg (preferred and alternate) are verified to remain constant within 1.0 psi of each other or each are individually verified to remain constant within 1.0 psi over time (i.e., between calibrations or over the course of the cycle).

At 100% power following refueling, average instrument readings are compared to equivalent average readings from the previous cycle and verified to agree within 0.5 psi.

If the above deviations exceed the specified tolerances, the impact of the difference are evaluated based on a sensitivity of 0.30% flow / psid. If non-conservative deviations beyond the specified tolerances can not be attributed to actual process changes, flow penalties are applied to reduce the COLSS indicated total flow rate. This will also reduce the Core Protection Calculator (CPC) flow rate when calibrated to COLSS flow.

Attachment to 2CAN070902 Page 2 of 21 The sensitivity of the flow to P is estimated by a simple increment based calculation of the flow using the COLSS flow algorithm implemented in a spreadsheet. Base values for the flow were determined using the same Cycle 15 plant data that were used in the process of calibrating COLSS flow to Cycle 1 and 2 calorimetric flows. The base P inputs were then incremented and the effect on the output of the COLSS flow algorithm recorded. Using this process, the effect of a 1 psid change on the volumetric flow in any one cold leg was determined to be 1.17% / psid. The impact is the same on the mass flow. The sensitivity of the total flow is a quarter of this impact (since there are four cold legs) or 0.30% / psid (conservatively rounded up) for the volumetric flow and the mass flow.

The surveillance criteria consist of the following for cold leg temperature instruments:

Verification that instrument quality indicated by the plant computer remains acceptable.

Unacceptable or questionable instrument quality is monitored by COLSS cross checks of preferred and alternate instruments.

The temperature instrumentation for each cold leg (preferred and alternate) is verified to remain constant within 2.0 °F of each other or each are individually verified to remain constant within 2.0 °F over time (i.e., over the course of the cycle).

At 100% power following refueling, average instrument readings is compared to equivalent average readings from the previous cycle and verified to agree within 1.0 °F.

If the above deviations exceed the specified tolerances, the impact of the difference is evaluated based on a sensitivity of 0.07% mass flow / °F. If non-conservative deviations beyond the specified tolerances can not be attributed to actual process changes, flow penalties are applied to reduce the COLSS indicated total mass flow rate. This will also reduce the CPC flow rate when calibrated to COLSS flow.

The sensitivity of the flow to cold leg temperature was estimated by an increment based calculation similar to that performed for the P sensitivity. The effect of a 1 °F change in any one cold leg was determined to be 0.15 % / °F on the volumetric flow and 0.28 % / °F on the mass flow. The sensitivity of the total flow is one quarter of this impact, or 0.04 % / °F for the volumetric flow and 0.07 % / °F for the mass flow.

2. Paragraph 5 of the RAI 1(b) response stated that Figure 4 provides an indication (excore raw signals) of the radial power distribution shift from the inside of the core to the outside of the core over the course of Cycle 15. Comparison of the trend in Figure 4 to Figures 2 and 3 clearly shows the influence that radial power distribution has on hot leg stratification.

Clarify how the above statements were obtained regarding Figure 4 about the radial power distribution shift and comparison of the trend in Figure 4 to Figures 2 and 3 about the influence of the radial power distribution on the hot leg stratification for Cycle 15.

This requested clarification is also applied to Figures 5 through 7 for Cycle 20.

The relationship between radial power distribution and the degree of hot leg stratification is hypothetical and not based on any rigorous derivation. Simply observing the temperature and Excore indications overlaying each other shows a correlation, supporting a reasonable conclusion that radial power distribution has an effect on stratification. The Excore signals are not a good representation of radial peaking, but are a reliable indication of relative power shifts between the core center and periphery. The correlation between the radial power shifts and

Attachment to 2CAN070902 Page 3 of 21 stratification is particularly evident in the inflection points of the trends (or the lack of inflections and continued steady trend in the case of Cycle 16). Improved trends over those provided in the previous RAI response (Reference 1) are attached as Figures 1 through 6. The improved trends show a simplified average Excore signal for a detector string (as opposed to the strings three subchannel signals) overlaid on the temperature data. Additional data to cover all cycles since steam generator replacement is also provided.

3. Paragraph 1 of the RAI 2(a) response indicated that the Cycles 1 and 2 calorimetric flow measurement were confirmed to be consistent with alternate, independent ultrasonic measurements not affected by flow streaming. An ultrasonic flow measurement was performed after loading the Cycle 1 fuel. The flow average from the two hot legs was determined to be 113.4% with a combined uncertainty of +7.6%.

(a) Specify the values of the calculated calorimetric flow rates and the associated combined uncertainty for Cycles 1 and 2, and justify that the calorimetric flow measurements are within the bounds of the ultrasonic flow measurements and with the RCP P flow measurements.

The calorimetric mass flow rate calculated as part of the Cycle 1 startup test plan was 110.3% (as stated in Paragraph 3 of the Reference 1 RAI 1(b) response). The calorimetric mass flow rate calculated as part of the Cycle 2 startup test plan was 111.01%. These measurements were performed at full power conditions (approximately 553 °F inlet temperature and 2250 psia for Cycles 1 and 2). The specific uncertainty of calorimetric flow measurements from the early cycles is not detailed in the measurement results or test procedures in effect at the time. The original uncertainty of calorimetric measurements is difficult to accurately determine. Various sources indicate the uncertainty applied at the time could have been anywhere between 2 and 6%. The uncertainty is assumed to be 3.0% of design mass flow. This value of the flow uncertainty corresponds to the last calorimetric flow uncertainty calculated for operation at the original power level (i.e., Cycle 15 conditions; the proposed COLSS calibration to Cycle 1 and 2 reference flow is performed using Cycle 15 P data).

Consistency with the independent ultrasonic flow measurement is intended to mean that the Cycle 1 and 2 calorimetric flow measurements were not shown to be grossly in error or non-conservative by comparison. The ultrasonic flow measurements were taken on each hot leg at hot zero power conditions (typically 545 °F and 2250 psia). The specific results are shown in Table 1 below.

TABLE 1 Flow Uncertainty Hot Leg #1 115.6%

+/- 3.7%

Hot Leg #2 111.2%

+/- 6.6%

Average 113.4%

6.7

)

6.6

(

)

7.3

(

2 2

Correcting for the density change between full and hot zero power conditions, the calorimetric based flow measurements adjust to approximately 111.6% and 112.1% of design mass flow for Cycles 1 and 2, respectively. The direct comparison of calorimetric

Attachment to 2CAN070902 Page 4 of 21 and ultrasonic flow rates at hot zero power conditions shows that both Cycle 1 and 2 calorimetric flow measurements are conservative with respect to the ultrasonic measurement. These measurements are also all within either methods uncertainty band of each other.

The COLSS RCP P based flow measurement has previously not been qualified as an independent measurement method (i.e., periodic calibration to a reference indication has always been performed). Use of pump P indications to validate Cycle 1 and 2 calorimetric or ultrasonic flow rates would therefore not be entirely appropriate. If desired to compare flow indicated by raw pump curves with Cycle 1 and 2 calorimetric or ultrasonic measurements, the best comparison is with the mass flow rates provided in Table 1 of the previous RAI response (Reference 1). The only uncertainty developed for P based flow measurements is that associated with the COLSS flow indication, which assumes calibration to a calorimetric reference indication. The uncertainty for the proposed COLSS indication was provided in response to previous RAI Question 2(c) (Reference 1).

(b) Provide the hot leg temperature measurements from all the temperature sensors for Cycles 1 and 2, and demonstrate that the differences of hot leg temperatures shown in Figures 2 and 3 for Cycle 15 and Figures 5 and 6 for Cycle 20 do not exist, and that the flow stratification in the hot legs is not of concern in calculating the RCS flow rate using the calorimetric flow method for Cycles 1 and 2.

The requested level of detail is not available for the early cycles (or time periods prior to 1995, in general). The detailed temperature sensor data shown in the previous RAI response (Reference 1) and shown in Figures 1 through 6 of this response was assembled from plant computer data archives. This archiving is made possible by advances in computer technology that have occurred since the early cycles. Flow surveillance records for the early cycles do not contain the same level of detail and in most cases only used half of the hot leg instrumentation available to determine average temperature. Regardless, the results of the Cycle 1 and 2 flow surveillances are supported (as conservative) by the ultrasonic flow measurement that was performed during Cycle 1 startup testing (see response to Question 3(a) of this submittal). Given the confirmation by ultrasonic means, there is no concern about stratification effects adversely impacting Cycle 1 and 2 calorimetric flow measurements.

(c) Provide the results of the ultrasonic flow measurements for Cycles 15 and 20, and demonstrate that the ultrasonic flow measurements are consistent with the RCP P flow measurements.

Ultrasonic flow measurements have not been performed beyond the first cycle. Similar to the Palo Verde ultrasonic flow measurements discussed in paragraph 10 to previous RAI response 2(b) (Reference 1), the ultrasonic flow measurements at ANO-2 were conducted during functional tests only as part of initial plant startup for Cycle 1. The measurements were conducted using temporary instrumentation installed on the hot legs. Unlike Palo Verde, ANO-2 ultrasonic measurement results were only documented for information purposes. They were not used at the time to adjust pump curves.

Attachment to 2CAN070902 Page 5 of 21

4. Paragraph 6 of the RAI 2(b) response indicated that guidelines were developed for periodic surveillance of the pump P and cold leg temperature instrumentation.

Discuss the criteria used in the guidelines to capture COLSS input data anomalies and ensure validity of flow measurement by compensating for any modified operation.

Please see the response to Question 1 of this submittal.

5. Paragraph 7 of the RAI 2(b) response claimed that the trends of pump P instrument shown in Figure 1 provide no evidence of degradation across recent cycles.

Figure 1 shows the from Cycles 16 to Cycle 19, the P readings from CPD6196A and CPD6196B changed significantly from cycle to cycle, and from Cycle 15 to Cycle 18, the P readings from CPD6196A were significantly different from CPD6196B. Explain the causes of the significant changes and differences of the P readings from CPD6196A and CDP6196B, and address their effects on the total RCS measured flow rate. Also, explain the significant differences (about 4 psi) in P readings from CPD6166 and CDP6186, and address the effect on the RCS flow measurement accuracy. In addition, expand Figure 1 by including the pump P data from Cycles 1 through 14 and show no pump degradation and no anomalies of pump P data for the whole RCP operating period.

Figure 1 of the previous (Reference 1) RAI response has been expanded to include data from Cycles 3 through 14, as well as additional data from Cycles 19 and 20 that had not previously been compiled. The expanded figure is included as Figure 7 of this submittal. Data earlier than shown is not available due to the fact that surveillance procedures in effect at the time did not record pump differential pressures. Plant computer archives of process parameters do not exist for time periods before approximately 1995.

The earlier cycle data is largely affected by the increase in steam generator tube plugging with occasional obvious calibration problems (between Cycles 5 and 6) or instrument hardware problems (one instrument in particular between Cycles 9 and 10). Significant improvements to the P instrument calibration procedure took place after Cycle 8. Static pressure biases were taken into account during calibrations from Cycle 9 forward and the consistency of instrument performance appears to improve as a result. The CPD6176A performance in Cycle 10 appears to be the result of a hardware problem that was corrected mid-way through the cycle.

With respect to the difference between CPD6186 and CPD6166 indications, these instruments are associated with different pumps. CPD6186 is associated with the C reactor coolant pump in Loop B and CPD6166 is associated with the A pump in Loop A. Direct comparison of the P magnitude between the two pumps has limited value, particularly since they are in different steam generator loops. Relevant comparisons are between A and B indications for the same pump (i.e., CPD6186A compared to CPD6186B and separate comparison of CPD6166A against CPD6166B). The A and B instruments for a given indication are independent measurements (aside from sharing a common pressure tap) of the P across the same pump.

Comparison of the A and B instruments on both of these pumps shows good agreement.

The relatively higher CPD6186 P readings associated with the C pump may be the result of local effects that result in a permanent bias. This conclusion is based on the lack of any technical information that would explain such a bias, except that pump casings are known to

Attachment to 2CAN070902 Page 6 of 21 have surface irregularities that could produce such a bias effect. As long as the bias remains consistent following calibration, the higher relative instrument readings for this pump have no effect on the accuracy of the flow measurement. The surveillance criteria described in response to Question 1 of this submittal will verify that consistency is maintained. The expanded data available in Figure 7 shows that the CPD6186 instruments have consistently been the highest P indications throughout plant life, regardless of steam generator replacement.

With respect to the CPD6196A and B observations (see Figure 7), these are indicative of instrumentation problems affecting both the primary and backup instrument for the same pump (a rare occurrence), not pump performance degradation. In particular, the instrument supplying the CPD6196A indication was affected by isolation valve leakage that prevented accurate calibration from at least the middle of Cycle 16 until isolation valves were replaced after Cycle 17. The instruments must be isolated from the process stream in order to perform calibration. The CPD6196B indication was affected by a bad transmitter prior to transmitter replacement after Cycle 16. The instrument performed as expected through Cycle 16 until calibrations were performed near end of Cycle 17. Near end of Cycle 17, maintenance records indicate the transmitter calibration was adjusted while at system pressure (for unknown reasons). This most certainly resulted in an erroneous calibration. Correction of these issues has led to normal operation of these indications from Cycle 19 on (Cycle 18 for CPD6196A).

Comparison of the CPD6196 instrument readings before and after corrective maintenance indicates that the P for this pump is higher than was indicated during Cycle 15 when the COLSS calibration constants were determined. Since a higher P equates to lower flow, the effect of the above maintenance issues on the total measured RCS flow rate (and the calibration constants determined for COLSS) is conservative. The surveillance criteria described in response to Question 1 of this submittal were developed as a result of these observations and will be used to identify and address any similar issue that occurs in the future. Should they occur in the future, penalties based on the sensitivities discussed in response to Question 1 of this submittal will be applied if the impact of these types of maintenance issues is determined to be non-conservative.

Finally, it is worth noting that the uncertainty analysis for the proposed COLSS P method uses a differential pressure instrument uncertainty based on drift of 2.16% instrument span covering up to a 22.5 month calibration interval (2). The instruments are calibrated over a 130 psi span, making this drift tolerance equal to a +/- 2.8 psi change in instrument accuracy between calibrations. Calibrations are performed approximately 18 months apart. The maximum as found error observed during calibrations performed since steam generator replacement is 1.13 psi (all but one data point is within +/- 1.0 psi). Although these as-found errors are a combination of drift, repeatability and calibration errors, they do support the conclusion that the P instruments are performing well within the bounds of uncertainty analyses, as long as hardware problems dont exist that introduce a bias (such as the CPD6196 issues discussed above).

Attachment to 2CAN070902 Page 7 of 21

6. Provide derivations for the following uncertainties in Table 4 of the RAI 2(c) response:

(a) +/- 5.2% and +/- 5.8% for the COLSS volumetric flow uncertainties and the CPC mass flow uncertainties used in the safety analysis, respectively.

(b) 4.1% and 2.9% for the COLSS mass flow uncertainty and the reference mass flow uncertainty used for Technical Specification monitoring of RCS flow, respectively.

The uncertainty analysis documenting the above values is proprietary to Westinghouse.

The analysis is available for review by the NRC at the Westinghouse Rockville, MD office July 20 and 21, 2009.

7. Since ANO2 and Palo Verde are CPC plants manufactured by CE, the CPC design and the methods for its associated RCS flow rate calibration are similar. However, the NRC staff finds that the monthly surveillance requirements (SRs) for the RCS calibration are different. Specifically, Palo Verde SR 3.3.1.5, corresponding to note (8) of TS TABLE 4.3-1of ANO2, states that:

With power levels greater than or equal to 70% of the rated thermal power, verify total RCS flow rate indicated by each CPC is less than or equal to the RCS flow determined either using the reactor coolant pump differential pressure instrumentation and the ultrasonic flow meter adjusted pump curves or by calorimetric calculations. This calibration is required to be performed once every 31 days.

It should be noted that the RCP curves used for the Palo Verde TS are adjusted by the measurements of the ultrasonic flow meter to assure the accuracy of the RCP flow measurement over an extensive period of time.

Justify the proposed removal of Note (8), instead of changing Note (8) to one similar to Palo Verde SR 3.3.1.5 to resolve the concern related to RCP flow measurement uncertainty over the whole RCP operating time until the RCPs are replaced.

Based on discussions with the NRC reviewer and Project Manager, it is Entergys understanding that this question was answered satisfactorily in the response to Question 2(b) of the previous RAI (Reference 1).

8. The following sentences were added (page 3): "Considering uncertainty in the actual surface roughness of the OSG and RSG tubes, the Cycle 15 calorimetric flow rate was lower than the best estimate predicted flow rate by at least 3% of the design mass flow rate. Considering RSG tolerances at the extreme producing the minimum predicted flow, the Cycle 15 calorimetric flow rate was lower by at least 2% of the design mass flow rate". Provide the derivations of 3% and 2% referenced above.

The predicted flow rates with replacement steam generators (RSGs) were developed as part of design calculations performed during the RSG project. The specific calculation supplying the predictions is proprietary to Westinghouse. Predictions of the RSG flow rate were made using computer codes benchmarked to original steam generator (OSG) based flow measurements and estimates of tube surface roughness in the OSGs and RSGs. Differing methodologies for determining surface roughness existed and resulted in varying flow predictions. The key results of the calculation are as follows:

Attachment to 2CAN070902 Page 8 of 21 TABLE 2 Case Steam Generator Inlet Temperature (°F)

Benchmark Factor Rx Vessel Net Flow (GPM) 3 RSG 551 1.0696 350,392 5

RSG 551 1.035 352,323 9

RSG 551 1.035 347,843 Cases 3 and 5 in Table 2 represent the difference in flow between methodologies used to estimate surface roughness. Case 9 assumes that all RSG manufacturing tolerances are at extremes producing the minimum flow rate.

The Table 2 volumetric flow rates were converted to mass flow rate at nominal Cycle 15 HFP operating conditions of 549 °F inlet temperature and pressure of 2200 psia:

TABLE 3 Case Volumetric Flow (GPM)

Specific Volume (549 °F, 2200 psia)

Mass Flow (lbm/hr)

% Design Mass Flow*

3 350,392 131.8 x 106 109.4%

5 352,323 132.5 x 106 110.0%

9 347,843 0.0213246 ft3/lbm 130.8 x 106 108.6%

• % Design Mass Flow = (Mass Flow / 120.4 x 106 ) x 100 Based on the above, the Cycle 15 average mass flow rate of 106.4% is at least 3% lower than best estimate predictions (Case 3 or 5) and at least 2% lower than minimum predicted flow (Case 9). An opportunity to review the proprietary Table 2 flow rate predictions can be arranged if desired.

References

1. 2CAN060901, Response to Request for Additional Information for the Technical Specification Change to Modify RCS Flow Verification Arkansas Nuclear One, Unit 2, dated June 1, 2009.

Attachment to 2CAN070902 Page 9 of 21 Figure 1A: ANO-2 Cycle 15 Loop A Hot Leg Temperatures Hot Full Power Data (T4635 Elements on East Side of Pipe, T4610 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 599 601 603 605 607 609 611 613 615 617 12/1/00 1/10/01 2/19/01 3/31/01 5/10/01 6/19/01 7/29/01 9/7/01 10/17/01 11/26/01 1/5/02 2/14/02 3/26/02 5/5/02 Date Deg. F 90 95 100 105 110 115 120 125 130 135 Excore Raw Avg (% Power)

T4635-1 T4635-2 T4635-3 T4635-4 T4610-1 T4610-2 T4610-3 T4610-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 10 of 21 Figure 1B: ANO-2 Cycle 15 Loop B Hot Leg Temperatures Hot Full Power Data (T4735 Elements on East Side of Pipe, T4710 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 599 601 603 605 607 609 611 613 615 617 12/1/00 1/10/01 2/19/01 3/31/01 5/10/01 6/19/01 7/29/01 9/7/01 10/17/01 11/26/01 1/5/02 2/14/02 3/26/02 5/5/02 Date Deg. F 90 95 100 105 110 115 120 125 130 135 Raw Excore Avg (% Power)

T4735-1 T4735-2 T4735-3 T4735-4 T4710-1 T4710-2 T4710-3 T4710-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 11 of 21 Figure 2A: ANO-2 Cycle 16 Loop A Hot Leg Temperatures Hot Full Power Data (T4635 Elements on East Side of Pipe, T4610 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 5/1/02 6/10/02 7/20/02 8/29/02 10/8/02 11/17/02 12/27/02 2/5/03 3/17/03 4/26/03 6/5/03 7/15/03 8/24/03 Date Deg. F 90 95 100 105 110 115 120 125 130 135 Excore Raw Avg (% Power)

T4635-1 T4635-2 T4635-3 T4635-4 T4610-1 T4610-2 T4610-3 T4610-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 12 of 21 Figure 2B: ANO-2 Cycle 16 Loop B Hot Leg Temperatures Hot Full Power Data (T4735 Elements on East Side of Pipe, T4710 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 5/1/02 6/10/02 7/20/02 8/29/02 10/8/02 11/17/02 12/27/02 2/5/03 3/17/03 4/26/03 6/5/03 7/15/03 8/24/03 Date Deg. F 90 95 100 105 110 115 120 125 130 135 Excore Raw Avg (% Power)

T4735-1 T4735-2 T4735-3 T4735-4 T4710-1 T4710-2 T4710-3 T4710-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 13 of 21 Figure 3A: ANO-2 Cycle 17 Loop A Hot Leg Temperatures Hot Full Power Data (T4635 Elements on East Side of Pipe, T4610 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 10/1/03 11/10/0 3

12/20/0 3

1/29/04 3/9/04 4/18/04 5/28/04 7/7/04 8/16/04 9/25/04 11/4/04 12/14/0 4

1/23/05 3/4/05 4/13/05 Date Deg. F 70 75 80 85 90 95 100 105 110 115 Excore Raw Avg (% Power)

T4635-1 T4635-2 T4635-3 T4635-4 T4610-1 T4610-2 T4610-3 T4610-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 14 of 21 Figure 3B: ANO-2 Cycle 17 Loop B Hot Leg Temperatures Hot Full Power Data (T4735 Elements on East Side of Pipe, T4710 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 10/1/03 11/10/0 3

12/20/0 3

1/29/04 3/9/04 4/18/04 5/28/04 7/7/04 8/16/04 9/25/04 11/4/04 12/14/0 4

1/23/05 3/4/05 4/13/05 Date Deg. F 70 75 80 85 90 95 100 105 110 115 Excore Raw Avg (% Power)

T4735-1 T4735-2 T4735-3 T4735-4 T4710-1 T4710-2 T4710-3 T4710-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 15 of 21 Figure 4A: ANO-2 Cycle 18 Loop A Hot Leg Temperatures Hot Full Power Data (T4635 Elements on East Side of Pipe, T4610 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 4/13/05 5/23/05 7/2/05 8/11/05 9/20/05 10/30/05 12/9/05 1/18/06 2/27/06 4/8/06 5/18/06 6/27/06 8/6/06 9/15/06 Date Deg. F 70 75 80 85 90 95 100 105 110 115 Excore Raw Avg (%Power)

T4635-1 T4635-2 T4635-3 T4635-4 T4610-1 T4610-2 T4610-3 T4610-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 16 of 21 Figure 4B: ANO-2 Cycle 18 Loop B Hot Leg Temperatures Hot Full Power Data (T4735 Elements on East Side of Pipe, T4710 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 4/13/05 5/23/05 7/2/05 8/11/05 9/20/05 10/30/05 12/9/05 1/18/06 2/27/06 4/8/06 5/18/06 6/27/06 8/6/06 9/15/06 Date Deg. F 70 75 80 85 90 95 100 105 110 115 Excore Raw Avg (% Power)

T4735-1 T4735-2 T4735-3 T4735-4 T4710-1 T4710-2 T4710-3 T4710-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 17 of 21 Figure 5A: ANO-2 Cycle 19 Loop A Hot Leg Temperatures Hot Full Power Data (T4635 Elements on East Side of Pipe, T4610 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 10/15/06 11/24/06 1/3/07 2/12/07 3/24/07 5/3/07 6/12/07 7/22/07 8/31/07 10/10/07 11/19/07 12/29/07 2/7/08 3/18/08 Date Deg. F 70 75 80 85 90 95 100 105 110 115 Excore Raw Avg (% Power)

T4635-1 T4635-2 T4635-3 T4635-4 T4610-1 T4610-2 T4610-3 T4610-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 18 of 21 Figure 5B: ANO-2 Cycle 19 Loop B Hot Leg Temperatures Hot Full Power Data (T4735 Elements on East Side of Pipe, T4710 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 10/15/06 11/24/06 1/3/07 2/12/07 3/24/07 5/3/07 6/12/07 7/22/07 8/31/07 10/10/07 11/19/07 12/29/07 2/7/08 3/18/08 Date Deg. F 70 75 80 85 90 95 100 105 110 115 Excore Raw Avg (% Power)

T4735-1 T4735-2 T4735-3 T4735-4 T4710-1 T4710-2 T4710-3 T4710-4 Excore Raw Avg Amplifier gain change

Attachment to 2CAN070902 Page 19 of 21 Figure 6A: ANO-2 Cycle 20 Loop A Hot Leg Temperatures Hot Full Power Data (T4635 Elements on East Side of Pipe, T4610 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 4/1/08 5/11/08 6/20/08 7/30/08 9/8/08 10/18/08 11/27/08 1/6/09 2/15/09 3/27/09 5/6/09 6/15/09 Date Deg. F 70 75 80 85 90 95 100 105 110 115 Excore Raw Avg (% Power)

T4635-1 T4635-2 T4635-3 T4635-4 T4610-1 T4610-2 T4610-3 T4610-4 Excore Raw Avg

Attachment to 2CAN070902 Page 20 of 21 Figure 6B: ANO-2 Cycle 20 Loop B Hot Leg Temperatures Hot Full Power Data (T4735 Elements on East Side of Pipe, T4710 Elements on West Side of Pipe. Channels 1, 2 & 3 on top, Channel 4 on Bottom) 603 605 607 609 611 613 615 617 619 621 4/1/08 5/11/08 6/20/08 7/30/08 9/8/08 10/18/08 11/27/08 1/6/09 2/15/09 3/27/09 5/6/09 6/15/09 Date Deg. F 70 75 80 85 90 95 100 105 110 115 Excore Raw Avg (% Power)

T4735-1 T4735-2 T4735-3 T4735-4 T4710-1 T4710-2 T4710-3 T4710-4 Excore Raw Avg

Attachment to 2CAN070902 Page 21 of 21 Figure 7: ANO-2 Reactor Coolant Pump Differential Pressures Full Power Conditions (Cycle 12 was limited to 98%)

81 83 85 87 89 91 93 95 97 8/1/82 4/27/85 1/22/88 10/18/90 7/14/93 4/9/96 1/4/99 9/30/01 6/26/04 3/23/07 12/17/09 Date Differential Pressure (PSI) 0 450 900 1350 1800 2250 2700 3150 3600 Tubes Plugged (Effective)

CPD6176A CPD6176B CPD6166A CPD6166B CPD6186A CPD6186B CPD6196A CPD6196B Tubes Plugged Cycle 20 Cycle 19 Cycle 18 Cycle 17 Cycle 16 Cycle 15 Cycle 14 Cycle 13 Cycle 12 Cycle 11 Cycle 10 Cycle 9 Cycle 8 Cycle 7 Cycle 6 Cycle 5 Cycle 4 Cycle 3 CPD6166A Xmitter replaced.

Significant calibration procedure improvement.

Steam Generator replacement.