DCL-07-002, Response to Request for Additional Information on License Amendment Request 07-01, Revision to Technical Specifications to Support Steam Generator Replacement.

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Response to Request for Additional Information on License Amendment Request 07-01, Revision to Technical Specifications to Support Steam Generator Replacement.
ML072840047
Person / Time
Site: Diablo Canyon  Pacific Gas & Electric icon.png
Issue date: 09/28/2007
From: Becker J
Pacific Gas & Electric Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
DCL-07-002, DCL-07-075, DCL-07-089
Download: ML072840047 (16)
v • d • e


Text

Electric Company

" Pacific Gasand Diablo Canyon Power Plant James R. Becker Vice President P 0. Box 56 Diablo Canyon Operations and Avila Beach, CA 93424 Station Director 805.545.3462 September 28, 2007 Fax: 805.545.4234 PG&E Letter DCL-07-089 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Response to Request for Additional Information on License Amendment Request 07-01, "Revision to Technical Specifications to Support Steam Generator Replacement"

References:

1. PG&E Letter DCL-07-002, "License Amendment Request 07-01, Revision to Technical Specifications to Support Steam Generator Replacement," dated January 11, 2007
2. PG&E Letter DCL-07-075, "Supplement to License Amendment Request 07-01, 'Revision to Technical Specifications to Support Steam Generator Replacement,' and Response to Request for Additional Information," dated August 9, 2007

Dear Commissioners and Staff:

Pacific Gas and Electric Company (PG&E) submitted License Amendment Request (LAR) 07-01, "Revision to Technical Specifications to Support Steam Generator Replacement," in Reference 1. LAR 07-01 proposes to revise Technical Specification (TS) 3.3.2, "Engineered Safety Feature Actuation System (ESFAS)

Instrumentation," to support replacement of the steam generators (SGs). A supplement to LAR 07-01 was submitted in Reference 2. The NRC provided requests for additional information on March 6, April 30, and July 31, 2007. This letter provides responses to these requests for additional information. This letter incorporates clarifications of the questions provided by the staff during phone calls held on June 25, July 13, and August 28, 2007.

This letter contains new commitments to be implemented following NRC approval of the LAR for each unit. The commitments are contained in Enclosure 2.

This information does not affect the results of the technical evaluation, or the no significant hazards consideration determination, previously transmitted in Reference 1.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

  • Comanche Peak
  • Diablo Canyon
  • Palo Verde
  • Wolf Creek

Document Control Desk PG&E Letter DCL-07-089 September 28, 2007 Page 2 If you have any questions, or require additional information, please contact Stan Ketelsen at (805) 545-4720.

I state under penalty of perjury that the foregoing is true and correct.

Executed on September 28, 2007.

Sincerely, James WR>ecker~

Vice President- Diablo Canyon Operationsand Station Director kjse/4328 Enclosures cc: Michael S. Peck, NRC Senior Resident Inspector Elmo E. Collins, NRC Region IV Sandra Shewry, DHS Diablo Distribution cc/enc: Alan B. Wang, Project Manager NRR A member of the STARS (Strategic Teaming and Resource Sharing). ALLiance Callaway

  • Comanche Peak
  • Diablo Canyon
  • Palo Verde
  • Wolf Creek

Enclosure 1 PG&E Letter DCL-07-089 Response to Request for Additional Information on License Amendment Request 07-01, "Revision to Technical Specifications to Support Steam Generator Replacement" NRC Question dated March 6, 2007:

In the license amendment request (LAR), Pacific Gas and Electric Company (PG&E) proposed to revise the technical specification (TS) TS 3.3.2, "EngineeredSafety Feature Actuation System (ESFAS) instrumentation."

1. Diablo Canyon PowerPlants (DCPP)Units 1 and 2 currently have Westinghouse Model 51 steam generators (SGs). New Westinghouse Model Delta-54, replacement SGs (RSGs) will be installedin Unit 2 during the next refueling outage, refueling outage 14 currently scheduled for February2008, and in Unit 1 during refueling outage 15 scheduled for January2009. The licensee considered the existing SGs and RSGs are similar, the SG replacementis being evaluated under 10 CFR 50.59.

Provide in detail a complete comparison of design parametersand operating range parametersfor both SG models.

PG&E Response:

The comparison Table of the operating and design parameters for the original SGs (OSG) and the RSGs for each unit is provided below.

Summary of OSG versus RSG Key Operating Parameters OSG RSG Thermal Design Parameters NSSS Power (%) 100 100 MWt 3425 3425 106 BTU/hr 11,687 11,687 Reactor Power (MWt) 3411 3411 106 BTU/hr 11,639 11,639 Thermal Design Flow (Loop gpm) (Unit 1) 87,700 87,700 Reactor 106 lb/hr (Unit 1) 132.9 132.8 Thermal Design Flow (Loop gpm) (Unit 2) 88,500 88,500 Reactor 106 lb/hr (Unit 2) 134.0 134.0 RCS Pressure (psia) 2250 2250 Core Bypass Flow ( %) (Unit 1) 7.5 7.5 1

Enclosure 1 PG&E Letter DCL-07-089 Summary of OSG versus RSG Key Operating Parameters OSG RSG Core Bypass Flow (%) (Unit 2) 9.0 9.0 Reactor Coolant Temperature (F)

Core Outlet (Unit 1) 614.8 614.8 Core Outlet (Unit 2) 615.8 615.8 Vessel Outlet 610.1 610.1 Core Average (Unit 1) 581.5 581.5 Core Average (Unit 2) 582.3 582.3 Vessel Average (Unit 1) 577.3 577.3 Vessel Average (Unit 2) 577.6 577.6 Vessel/Core Inlet (Unit 1) 544.5 544.5 Vessel/Core Inlet (Unit 2) 545.1 545.1 Steam Generator Outlet (Unit 1) 544.2 544.2 Steam Generator Outlet (Unit 2) 544.8 544.8 Steam Generator Model 51 Delta 54 Shell Design Pressure (psia) 1100 1100 Steam Outlet Temperature (F) (Unit 1) 518.2 521.2 Steam Outlet Temperature (F) (Unit 2) 518.8 521.7 Steam Outlet Pressure (psia) (Unit 1) 800 821 Steam Outlet Pressure (psia) (Unit 2) 804 824 Steam Outlet Flow (106 lb/hr total) 14.91 14.90 Feed Temperature (F) 435.0 435.0 Steam Outlet Moisture % max 0.25 0.05 Fouling Factor (hr. sq. ft. F /BTU) 0.00018 0.00018 Tube Plugging (%) 0 0 Zero Load Temperature (F) 547 547 Hydraulic Design Parameters Reactor Coolant Pump Model 93A 93A Pump Horsepower 6000 6000 Pump Frequency (Hz) 60 60 Pump Design Point (gpm/Head (ft.)) 88,500/277 88,500/277 Mechanical Design Flow (gpm/loop) (Unit 1) 99,600 99,600 2

Enclosure 1 PG&E Letter DCL-07-089 Summary of OSG versus RSG Key Operating Parameters OSG RSG Mechanical Design Flow (gpm/loop) (Unit 2) 102,000 102,000 Minimum Measured Flow (gpm)1 (Unit 1) 359,200 359,200 1

Minimum Measured Flow (gpm) (Unit 2) 362,500 362,500 Note 1. Minimum Measured Flow is based on 2.3% flow uncertainty.

Summary of OSG versus RSG Key Design Parameters Design Parameters OSG RSG SG volume, ft 3 (primary side, no plugged tubes) 1089 1016 SG Tubes, # 3388 4444 SG Tubes, Material Alloy 600MA Alloy 690TT SG Tubes OD, in 0.875 0.750 SG Tubes Wall Thickness, in 0.050 0.043 2

SG Tubes Heat Transfer Area, ft (secondary side) 51500 54240 SG Circulation Ratio 3.58 4.07 SG Secondary Side Volume, ft3 5730 5802 SG Total Weight, 10 3 lbs (dry) 660 687.5+/- 15 SG Center of Gravity, in (dry) 350.4 348 4 SG Integral Outlet Flow Restrictor NO YES 3

Enclosure 1 PG&E Letter DCL-07-089 NRC Question dated April 30, 2007:

By letter dated January 11, 2007 (ML070190094), Pacific Gas and Electric Company (the licensee) submitted a license amendment request to revise the Diablo Canyon Units 1 and 2 technicalspecifications as a result of the SG replacementproject. The proposed amendment would, in part, revise the existing SG tube surveillance program to be consistent with the U.S. Nuclear Regulatory Commission's approved Technical Specification Task Force (TSTF) Standard Technical Specification Change Traveler, TSTF-449, "Steam GeneratorTube Integrity," Revision 4.

The staff of the Steam GeneratorTube Integrity and Chemical Engineering Branch of the Division of Component Integrity has reviewed the information the licensee provided and determined that additionalinformation is requiredin order to complete our portion of the evaluation.

1) Please confirm you verified (using the methodology in Regulatory Guide 1.121) that the 40 percent depth-based tube repaircriteriaremains appropriatefor the replacement SGs.

PG&E Response:

A Regulatory Guide 1.121 analysis has been performed to determine the structural limits for tube wear, which is the only potential degradation mechanism for the replacement SGs. The analysis also verifies that accident condition bending stresses for large radius U-bends do not affect the burst strength. The structural limits include sufficient margin to satisfy the 40 percent depth-based tube plugging criteria, accounting for nondestructive examination uncertainty and an allowance for flaw growth. The structural limits for a crack or more localized damage would be greater than the structural limits for tube wear, and, therefore, would also have sufficient margin to satisfy the 40 percent depth-based tube plugging criteria. Should cracking or more localized damage be identified as a potential damage mechanism in the future as the SGs age, structural limits for these mechanisms would be calculated as part of the degradation assessment to support condition monitoring and operational assessments.

NRC Question dated July 31, 2007:

The LAR, proposes the following TS changes:

Revise the Allowable Value (A V) and Nominal Trip Setpoint (NTSP) for SG Water Level-High High Function in TS Table 3.3.2-1, Engineered Safety Feature Actuation System Instrumentation,from < 75.2% and < 75.0% to < 90.2% and

< 90.0%, respectively.

To support NRC assessment of this TS change request please provide:

4

Enclosure 1 PG&E Letter DCL-07-089

1. Documentation, including sample calculation of the methodology used for establishingthe (NTSP) and the limiting acceptable values for the as-found and as-left setpoints as measured during the periodic surveillance testing. Indicate the related analytical limits and other limiting design values and the sources of these values.

PG&E Response:

PG&E submitted the DCPP setpoint methodology and the calculation of the NTSPs and AVs in WCAP-1 1082, Revision 6, which was submitted in PG&E Letter DCL-03-111, "License Amendment Request 03-12, Revision to Technical Specifications 3.3.1, 'RTS Instrumentation,' and 3.3.2, 'ESFAS Instrumentation,"' dated September 12, 2003.

The methodology for calculating the revised TS 3.3.2 ESFAS Function 5.b, "Feedwater Isolation, SG Water Level-High High (P-14)," NTSP and AV proposed in PG&E Letter dated January 11, 2007, is the same as previously described in WCAP-1 1082, Revision

6. The methodology in WCAP-1 1082, Revision 6, was approved for use for DCPP by the NRC in Amendment No. 178 to Facility Operating License No. DPR-80, and Amendment No. 180 to Facility Operating License No. DPR 82, in PG&E Letter, "Diablo Canyon Power Plant, Unit Nos. 1 and 2 - Issuance of Amendment Re: Revised Technical Specifications 3.3.1, 'Reactor Trip System (RTS) Instrumentation' and 3.3.2,

'Engineered Safety Feature Actuation System (ESFAS) Instrumentation' (TAC Nos.

MC0893 and MC0894)," dated December 2, 2004. The revised inputs to the SG level uncertainty analysis are provided in Enclosure 9 of PG&E Letter DCL-07-075, "Supplement to License Amendment Request 07-01, 'Revision to Technical Specifications to Support Steam Generator Replacement,' and Response to Request For Additional Information,"' dated August 9, 2007.

The current methodology for as-found and as-left acceptance criteria is described in WCAP-1 1082, Revision 6, Section 4.3, "Process Rack Operability Determination Program and Criteria." Section 4.3 discusses the program that defines the operability criteria for the Eagle 21 digital process racks. Since the process racks are self-checking, the critical parameter is the ability of the process racks to be calibrated within the rack calibration accuracy. These values are currently found in the plant calibration procedures as the as left calibration accuracy, and are consistent with the Eagle 21 card/channel analog input verification test criteria values provided in paragraph 1 of Section 4.3 (page 4-4) of WCAP-1 1082, Revision 6 for:

EAI ERI-NR (TEMP)

ERI-WR (TEMP)

ERI-WR (Voltage)

Paragraphs 2 and 3 of WCAP-1 1082, Revision 6, Section 4.3, state as follows:

5

Enclosure 1 PG&E Letter DCL-07-089 A channel found in excess of the Rack CalibrationAccuracy and less than or equal to the Allowable Value, designated as (RD [rack drift] + RMTE [rack measuring and test equipment accuracy]), should be consideredoperable if the "asleft" condition can be returned to within the rack calibrationaccuracy. If the measured setpoint is found in excess of the Allowable Value, the channel bistable/outputdevice must be evaluated for operability. The channel will be considered inoperableif it cannot be returned to within the rack calibrationaccuracyregardlessof the "asfound" value. The Allowable Values are defined as:

EAI 0.20 % Span ERI-NR (TEMP) 0.30 % Span ERI-WR (TEMP) 0.20 % Span ERI-WR (Voltage) 0.20 % Span For the nuclearinstrument channels, PG&E will use the same definition for Allowable Value as is being applied to the otherchannels in this setpoint study, i.e., the difference between the Allowable Value and the Nominal Trip Setpoint equals Rack Drift plus Rack Measuring & Test Equipment accuracy.

The methodology to calculate the as-left tolerance is plus or minus the rack calibration accuracy. This methodology results in an as-left tolerance which is more conservative than that required by TSTF Standard TS Change Traveler, TSTF-493, Revision 2, "Clarify Application of Setpoint Methodology for LSSS Functions," dated April 16, 2007, which states, "The Nominal Trip Setpoint must be reset or left within the as-left tolerance at the end of every surveillance that requires setpoint verification. The ability to reset the setpoint represents continued confidence that the channel can perform its intended safety function. The as-left tolerance may include the reference accuracy, measuring and test equipment accuracy and readability uncertainties."

The methodology to calculate the as-found tolerance is plus or minus the RD plus the rack measurement and test equipment (M&TE) accuracy (0.2 percent as indicated above). This methodology results in an as-found tolerance that is more conservative than that required by TSTF-493, Revision 2, which states, "The as-found trip setpoint must be verified to be within predefined double-sided limits that are based on the actual expected errors between calibrations. Finding the as-found trip setpoint outside these limits warrants additional evaluation and corrective action, as necessary, to ensure continued performance of the specified safety function. Normally, the as-found tolerance will be equivalent to the errors verified during the surveillance (e.g. Reference Accuracy, drift, and M&TE accuracy/errors)."

The safety analysis limit (SAL) for TS 3.3.2 ESFAS Function 5.b is 100 percent SG narrow range level span and the source is the Final Safety Analysis Report Update (FSARU) Chapter 15 excessive heat removal due to feedwater system malfunction analysis that credits ESFAS Function 5.b to provide feedwater isolation. When determining the NTSP for ESFAS Function 5.b in the SG narrow range level uncertainty 6

Enclosure 1 PG&E Letter DCL-07-089 calculation, the lower of the SAL value or the maximum reliable indicated level (MRIL) value is used. The MRIL accounts for the error due to the void content of the two-phase mixture above the mid-deck plate as described in Westinghouse Letter NSAL-02-4, "Maximum Reliable Indicated Steam Generator Water Level," dated February 19, 2002.

Since the MRIL value is lower than the SAL value for ESFAS Function 5.b, the MRIL is the analytical limit for ESFAS Function 5.b that is used in the SG narrow range level uncertainty calculation. When the MRIL is lower than the SG narrow range level span value credited for ESFAS Function 5.b in the FSARU Chapter 15 analysis for excessive heat removal due to feedwater system malfunction, the MRIL value is sometimes referred to as the SAL for ESFAS Function 5.b.

2. The NRC letter to the NEI SMTF dated September 7, 2005 (ML052500004),

describes the information to be provided in the TS amendment request.

Specifically, describe how surveillance test results and associated TS limits are used to establish operability of the safety system. Show that this evaluation is consistent with the assumptions and results of the setpoint calculation methodology.

PG&E Response:

Pages 10-12 of PG&E Letter dated January 11, 2007, addressed the seven specific concepts of the NRC setpoint issues and how they are being met for the proposed ESFAS Function 5.b setpoint change. PG&E is applying the generic industry changes contained in TSTF-493, Revision 2, to ESFAS Function 5.b to address the NRC setpoint issues contained in the NEI Letter dated September 7, 2005. In PG&E Letter dated August 9, 2007, PG&E provided changes to ESFAS Function 5.b based on TSTF-493, Revision 2.

The DCPP setpoint methodology in WCAP-1 1082, Revision 6, Section 4, "Application of the Setpoint Methodology," discusses the plant surveillance procedure requirements that are needed to maintain consistency with the assumptions of the setpoint methodology. The first paragraph of WCAP-1 1082, Revision 6, Section 4.1, "Uncertainty Calculation Basic Assumptions/Premises," states:

1. The instrument techniciansoptimize, within the calibrationtolerance, the Nominal Setpoint's "asleft" condition at the start of each process rack's surveillance interval,
2. The instrument techniciansoptimize, within the calibrationtolerance, the sensor/transmitter's"asleft" condition at the startof each surveillance interval,
3. The process rack drift is limited by the Eagle 21 self-checking feature, 7

Enclosure 1 PG&E Letter DCL-07-089

4. The sensor/transmitterdrift is trended over the fuel cycle and evaluated (probability distribution function characteristicsand drift magnitude) over multiple fuel cycles,
5. The sensor/transmittercalibration accuracy is evaluated (probabilitydistribution function characteristicsand magnitude) over multiple surveillance intervals,
6. The sensor/transmittersare calibratedusing a one up and one down pass utilizing multiple calibrationpoints (minimum 5 points, as recommended by ISA51. 1).

The third paragraph of WCAP-1 1082, Revision 6, Section 4.1, states:

In summary, a sensor/transmitteror a process rack channel is considered to be "calibrated"when the two-sided "asleft" calibrationproceduraltolerance is satisfied. An instrument technician may decide to recalibrateif the "asfound" condition is near the extremes of the "asleft" proceduraltolerance, but is not required to do so. Recalibration is explicitly required any time the "asfound" condition of the device or channel is outside of the "asleft" proceduraltolerance. A device or channel may not be left outside the "asleft" tolerance without declaringthe channel "inoperable"and appropriateaction taken. Thus an "asleft" tolerance may be considered as an outer limit for the purposes of calibrationand instrument uncertainty calculations.

For DCPP, the Corrective Action Program procedure is OM7, "Corrective Action Program," and problems are documented per procedure OM7.ID1, "Problem Identification and Resolution - Action Requests." The Corrective Action Program includes a process to perform a TS operability review, and document as necessary per procedure OM7.1D12, "Operability Determination," and to determine the necessary corrective actions to be taken, including corrective actions to prevent recurrence, per Procedure OM7.1D1. Currently, an issue is entered into the Corrective Action Program through entry of an Action Request into a computer based program.

At DCPP, setpoints are controlled using a graded approach by procedure CF6.ID1, "Setpoint Control Program," a procedure controlled under 10 CFR 50.59. The instrument setpoints are divided into five groups depending on the instrument function and instrument classification. Setpoint Category A setpoints are those that are safety related reactor protection and ESFAS setpoints. Procedure CF6.ID1 contains the following requirements for Category A setpoints, which includes the Category A ESFAS Function 5.b:

  • Changes to these setpoints or their control basis require a design change vehicle.

" The design basis or safety analysis limits for these setpoints shall be documented.

8

Enclosure 1 PG&E Letter DCL-07-089

  • Uncertainty/setpoint calculation for these setpoints shall be performed using the methodology provided in WCAP-1 1082 and shall include AV determination for the setpoint and sensor as-found criteria for transmitter outputs.
  • A Corrective Action Program out-of-tolerance Action Request shall be written if the AV is exceeded or the sensor as-found criteria is exceeded.

Surveillance Requirements (SR) 3.3.2.5 and 3.3.2.9 are performed for ESFAS Function 5.b using surveillance test procedures that are controlled under 10 CFR 50.59.

SR 3.3.2.5 is for performance of the channel operational test and SR 3.3.2.9 is for the performance of the channel calibration. In order to perform SR 3.3.2.5 and 3.3.2.9, a SG narrow range level channel is placed in bypass or trip which causes the channel to be inoperable per TS 3.3.2. Therefore, when taking a channel out of service to perform SR 3.3.2.5 and 3.3.2.9, Procedure OP1.DC17, "Control of Equipment Required by the Plant Technical Specification or Other Designated Programs," requires that the channel be declared inoperable, and the applicable TS condition be entered. For the performance of SR 3.3.2.5 and 3.3.2.9 for ESFAS Function 5.b, the applicable TS 3.3.2 condition per TS Table 3.3.2-1 is Condition J. For Condition J, Required Action J.1, requires the channel to be placed in trip with a Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or Condition J.2 requires the unit to be in Mode 3 with a Completion Time of 78 hours9.027778e-4 days <br />0.0217 hours <br />1.289683e-4 weeks <br />2.9679e-5 months <br />.

The performance of SR 3.3.2.5 or 3.3.2.9 for ESFAS Function 5.b takes considerably less than 78 hours9.027778e-4 days <br />0.0217 hours <br />1.289683e-4 weeks <br />2.9679e-5 months <br /> and thus, during performance of the SR, the channel may only be placed in bypass since the procedure allows the channel to be tested while placed in bypass.

WCAP-1 1082, Revision 6, Section 4.3, requires that the procedures contain an as-found tolerance. The surveillance test procedures, which are applicable to ESFAS Function 5.b, require that if the as-found date exceeds the TS and Equipment Control Guideline out-of-tolerance accuracy, the supervisor is notified, and an Action Request is initiated in the Corrective Action Program. The surveillance test procedures also verify that the as-left calibration values are within the desired double-sided as-left tolerance.

The as-found tolerance is a double-sided tolerance of +0.20 percent for the proposed ESFAS Function 5.b NTSP of 90 percent. Because of the conservative method in which the AV has been calculated (RD plus rack measurement and test equipment accuracy ), the as-found value for the upper side of the as-found tolerance is the same as the proposed TS 3.3.2 ESFAS Function 5.b AV of 90.2 percent. For the normal situation when the instrument setpoint is set at the NTSP of 90 percent, when the upper side of the as-found tolerance is exceeded (i.e., greater than 90.2 percent), the AV is also exceeded. Therefore, when the as-found value is greater than 90.2 percent, the Action Request initiated in the Corrective Action Program will address both the as-found tolerance and AV being exceeded. When the as-found value is less than 89.8 percent, the Action Request initiated in the Corrective Action Program will address the as-found tolerance being exceeded. Per the requirements of WCAP-11082, Revision 6, Section 4.3, the instrument characteristics are evaluated in conjunction with the previous experience for the device to determine whether the performance is within the 9

Enclosure 1 PG&E Letter DCL-07-089 assumptions of the statistical setpoint study, and the evaluation considers the ability to reset the instrument within the as-left tolerance and the qualitative response characteristics. The instrument channel cannot be returned to service and declared operable unless the setpoint can be reset to within the as-left setpoint and the evaluation of the channel shows it is functioning as required.

The proposed changes to ESFAS Function 5.b add notes to SR 3.3.2.5 and 3.3.2.9 for ESFAS Function 5.b in TS Table 3.3.2-1. The note added to SR 3.3.2.5 requires that if the as-found channel setpoint is outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service. The changes to the TS 3.3.2 Bases for SR 3.3.2.5 require that when the as-found channel setpoint is outside its predefined as-found tolerance but conservative with respect to the AV, the performance of the channel be evaluated per the plant Corrective Action Program. The revised TS 3.3.2 Bases for SR 3.3.2.5 state that the purpose of the evaluation to ensure confidence in the instrument performance prior to returning the instrument to service and that entry into the Corrective Action Program will ensure required review and documentation of the condition for continued OPERABILITY. The note added to SR 3.3.2.9 requires the instrument channel setpoint be reset to a value that is within the as-left tolerance around the NTSP at the completion of the surveillance; otherwise, the channel shall be declared inoperable.

The note added to SR 3.3.2.9 states that setpoints more conservative than the NTSP are acceptable provided that the as-found and as-left tolerances apply to the actual setpoint implemented in the surveillance procedures to confirm channel performance.

The revised TS 3.3.2 Bases for SR 3.3.2.9 state where a setpoint more conservative than the NTSP is used in the plant surveillance procedures, the as-left and as-found tolerances will be applied to the surveillance procedure setpoint to ensure that sufficient margin to the safety limit and/or analytical limit is maintained. The proposed notes to SR 3.3.2.5 and 3.3.2.9 for ESFAS Function 5.b in TS Table 3.3.2-1, and the proposed changes to the TS 3.3.2 Bases for SR 3.3.2.5 and SR 3.3.2.9 for ESFAS Function 5.b, will ensure the channel is operable and has margin to the safety limit and/or analytical limit following return to service from the surveillances.

In order to provide compliance with the proposed notes to SR 3.3.2.5 and 3.3.2.9 for ESFAS Function 5.b in TS Table 3.3.2-1, and the proposed changes to the TS 3.3.2 Bases for SR 3.3.2.5 and SR 3.3.2.9 for ESFAS Function 5.b, the 10 CFR 50.59 controlled surveillance test procedures applicable to ESFAS Function 5.b will be updated as required as part of implementation of the amendment for each unit. The Actions for the various potential surveillance outcomes will be required as follows:

The instrument channel setpoint exceeds the as-left tolerance but is within the as-found tolerance:

0 Reset the instrument channel setpoint to within the as-left tolerance; 10

Enclosure 1 PG&E Letter DCL-07-089

  • If the instrument channel setpoint cannot be reset to a value that is within the as-left tolerance around the instrument channel setpoint at the completion of the surveillance, if not already inoperable, the instrument channel shall be declared inoperable.

The instrument channel setpoint exceeds the as-found tolerance but is conservative with respect to the TS AV:

" Reset the instrument channel setpoint to within the as-left tolerance;

  • If the instrument channel setpoint cannot be reset to a value that is within the as-left tolerance around the instrument channel setpoint at the completion of the surveillance, if not already inoperable, the instrument channel shall be declared inoperable;

" Enter the channel's as-found condition in the Corrective Action Program for prompt verification that the instrument is functioning as required, and further evaluation. Evaluate the channel performance utilizing available information to verify that it is functioning as required before returning the channel to service. The evaluation may include an evaluation of magnitude of change per unit time, response of instrument for reset, previous history, etc., to provide confidence that the channel will perform its specified safety function;

" Document the condition for continued OPERABILITY.

The instrument channel setpoint is non-conservative with respect to the TS AV:

  • Reset the instrument channel setpoint to within the as-left tolerance;

" Enter the channel's as-found condition in the Corrective Action Program for evaluation. Evaluate the channel performance utilizing available information to verify that it is functioning as required before returning the channel to service. The evaluation may include an evaluation of magnitude of change per unit time, response of instrument for reset, previous history, etc., to provide confidence that the channel will perform its specified safety function.

These procedure actions are the minimum actions which the procedures will require and additional actions may be taken. These procedure actions will apply until procedure actions consistent with a license amendment for TSTF-493 are implemented for all ESFAS Table 3.3.2-1 functions.

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Enclosure 1 PG&E Letter DCL-07-089

3. Discuss the plant corrective action processes, including plant procedures, for restoringchannels to operable status when channels are determined to be "inoperable"or "operablebut degraded." If the criteriafor determining operability of the instrument being tested are located in a document other than the TS, e.g.

plant test procedure, explain how the requirementsof 10 CFR 50.36 are met.

PG&E Response:

The plant corrective action processes, the WCAP-1 1082 setpoint methodology requirements, the plant procedures for control of setpoints, and the plant procedures for restoring ESFAS Function 5.b channels to operable status when they are determined to be inoperable or degraded are contained in the response to Question 2.

The NTSP and the AV, which is used to determine TS operability for ESFAS Function 5.b, is contained in TS Table 3.3.2-1 and, therefore, meets 10 CFR 50.36.

The proposed changes to ESFAS Function 5.b add notes to SR 3.3.2.5 and 3.3.2.9 for ESFAS Function 5.b in TS Table 3.3.2-1. The note added to SR 3.3.2.9 requires that the methodologies used to determine the as-found and as-left tolerances are specified in the Equipment Control Guidelines. Therefore, the methodologies to determine the as-found and as-left tolerances will be included in TS Table 3.3.2-1 by reference and, therefore, will meet 10 CFR 50.36.

As stated in the response to Question 2, to provide compliance with the proposed note to SR 3.3.2.5 for ESFAS Function 5.b in TS Table 3.3.2-1, and the proposed changes to the TS 3.3.2 Bases for SR 3.3.2.5, the 10 CFR 50.59 controlled surveillance test procedures applicable to ESFAS Function 5.b will be updated as part of implementation of the amendment for each unit to require that when the instrument channel setpoint is nonconservative with respect to the as-found tolerance or the TS AV, the Corrective Action Program will be entered to evaluate the channel's as-found condition. Since the surveillance test procedures applicable to ESFAS Function 5.b are controlled under 10 CFR 50.59, the 10 CFR 50.36 requirement that when an automatic safety system does not function as required, to review the matter, and record the results of the review, including the cause of the condition and the basis for corrective action taken to preclude recurrence, will be met.

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Enclosure 2 PG&E Letter DCL-07-089 Regulatory Commitments

1. In order to provide compliance with the proposed notes to Surveillance Requirements (SR) 3.3.2.5 and 3.3.2.9 for Engineered Safety Feature Actuation System (ESFAS) Function 5.b in TS Table 3.3.2-1, and the proposed changes to the Technical Specification (TS) 3.3.2 Bases for SR 3.3.2.5 and SR 3.3.2.9 for ESFAS Function 5.b, the 10 CFR 50.59 controlled surveillance test procedures applicable to ESFAS Function 5.b will be updated as required as part of implementation of the amendment for each unit. The Actions for the various potential surveillance outcomes will be required as follows:

The instrument channel setpoint exceeds the as-left tolerance but is within the as-found tolerance:

  • Reset the instrument channel setpoint to within the as-left tolerance;
  • If the instrument channel setpoint cannot be reset to a value that is within the as-left tolerance around the instrument channel setpoint at the completion of the surveillance, if not already inoperable, the instrument channel shall be declared inoperable.

The instrument channel setpoint exceeds the as-found tolerance but is conservative with respect to the TS Allowable Value (AV):

  • Reset the instrument channel setpoint to within the as-left tolerance;

" If the instrument channel setpoint cannot be reset to a value that is within the as-left tolerance around the instrument channel setpoint at the completion of the surveillance, if not already inoperable, the instrument channel shall be declared inoperable;

  • Enter the channel's as-found condition in the Corrective Action Program for prompt verification that the instrument is functioning as required and further evaluation. Evaluate the channel performance utilizing available information to verify that it is functioning as required before returning the channel to service. The evaluation may include an evaluation of magnitude of change per unit time, response of instrument for reset, previous history, etc., to provide confidence that the channel will perform its specified safety function;

The instrument channel setpoint is non-conservative with respect to the TS AV:

0 If not already inoperable, declare the channel inoperable; 1

Enclosure 2 PG&E Letter DCL-07-089

" Reset the instrument channel setpoint to within the as-left tolerance;

" Enter the channel's as-found condition in the Corrective Action Program for evaluation. Evaluate the channel performance utilizing available information to verify that it is functioning as required before returning the channel to service. The evaluation may include an evaluation of magnitude of change per unit time, response of instrument for reset, previous history, etc., to provide confidence that the channel will perform its specified safety function.

These procedure actions are the minimum actions which the procedures will require and additional actions may be taken. These procedure actions will apply until procedure actions consistent with a license amendment for Technical Specification Task Force TSTF-493 are implemented for all ESFAS Table 3.3.2-1 functions.

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