ML20044H325
| ML20044H325 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 05/28/1993 |
| From: | Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20044H326 | List: |
| References | |
| NUDOCS 9306080187 | |
| Download: ML20044H325 (17) | |
Text
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PIIILADELPHIA ELECTRIC COMPANY NUCLEAR GROUP HEADQUARTERS 955-65 CHESTERBROOK BLVD. May 28, 1993 WAYNE, PA 19087-5691 Docket Nos. 50-277 ms> womx) 50-278 License Nos. DPR-44 DPR-56 STATION SUPPORT DEPARTMENT U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Peach Bottom Atomic Power Station, Units 2 and 3 Request for Additional Information Regarding Applications to Revise Technical Specifications to Accommodato a 24 Month Fuel Cycle
Reference:
- 1) Technical Specification Change Request 92-03, ,
Non-Instrument Surveillance Requirements G. J. Beck, PECo to USNRC, September 28, 1992
- 2) Technical Specification Change Request 92-04, Instrumentation Requirements G. J. Beck, PECo to USNRC, October 19, 1992
- 3) Request for Additional Information, USNRC to PECo, April 30, 1993
Dear Sir:
By the reference letter 3, the NRC has requested additional information regarding our proposed amendments to the Peach Bottom Atomic Power Station (PBAPS) Facility Operating Licenses. The amendments were proposed in two separate submittals. The first submittal, reference 1, requested changes to non-instrument surveillance requirements to accommodate a 24 month fuel cycle.
The second submittal, reference 2, requested changes to instrumentation calibration frequency and when combined with reference 1, provides justification for changing the definitions of operating cycle and refuel cycle. In addition to the 25 questions provided in reference 3, three requests were made during a telephone conversation between the NRC and PECo on May 10, 1993, and three more concerns were identified in subsequent conversations. Each of the 31 requests is restated in the enclosure to this letter along with our response.
630030 ( g 9306000187 930529 i-PDR ADOCK 05000277 P ppg (\
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U.S. Nuclear Regulatory Commission May 28, 1993 Document Control Desk Page 2 This information is being provided under affirmation. If you have any questions, please feel free to contact us.
Si cerely,
.d h G. A. Hunger, F., #irector s
Licensing.Section Attachments: Affidavit Enclosure .
Attachments 1 through 4 cc: T. T. Martin, Administrator, Region I, USNRC USNRC Senior Resident Inspector, PBAPS i
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COMMONWEALTH OF PENNSYLVANIA:
- ss.
COUNTY OF CHESTER :
G. R. Rainey, being first duly sworn, deposes and says:
That he is Vice President of Philadelphia Electric Company; the Applicant herein; that he has read the attached response to the NRC's Request for Additional Information for Peach Bottom Atomic Power Station Facility Operating Licenses DPR-44 and DPR-56, knows the contents thereof; and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief. ,
'bA WS j'fVice 'UV President l
I subscribed and sworn to before me this day of 1993. .
'l Notary Public
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ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED REVISIONS TO THE PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3, TECHNICAL SPECIFICATIONS RELATING TO 24-MONTHS OPERATING CYCLE SURVEILLANCE REQUIREMENTS DOCKET NOS. 50-277 AND 50-278 A. Instrument-Related Questions
- 1. Explain the relationship between the " procedure drift allowance" as referenced in the Peach Bottom submittal and the " leave alone zone" (LAZ) and design allowance / allowable value as referenced in the General-Electric (GE) setpoint methodology. The GE setpoint methodology states that the derivation of the LAZ is determined by the individual utility setpoint results. The GE design allowance incorporates temperature, -
calibration and drift errors. It is not clear what terms are included in the Peach Bottom procedure drift allowance', provide details.
Response
There is no direct relationship between the terms used in the General Electric setpoint methodology and the terms used in the PBAPS submittal.
The General Electric setpoint methodology was developed around the present Standard Technical Specifications format while Peach _ Bottom is operating under the original custom Technical Specification format.
With the development of both the General Electric Setpoint methodology ,
(NEDC-31336) and the Instrument Society of America standard ISA-567.04, i "Setpoints for Nuclear Safety-Related Instrumentation used in Nuclear Power Plants," PECo revised the procedure for Instrument Setpoint Calculations to address the error (uncertainty) terms on an individual basis for safety-related setpoints. The term " procedure drift allowance" as used in the PBAPS submittals is the difference between the.
" leave alone zone" and the TS value for protective actions.
- 2. Confirm that the methodology for determining a vendor (Rosemount, etc.)
24-month drift term is consistent with the GE drift methodology.
Provide details. For example, discuss 95/95 criteria, number _ of data points, length of test, methodology in determining an extended surveillance drift value, and applicability to currently installed instrumentation as appropriate. Provide a copy or summary of any applicable vendor reports that justify a 24-month interval.
1 l
Response
The General Electric methodology does not address how the vendor l' determines the drift specification for his instrument. The methodology uses the drift specification from vendor literature. A copy of the Rosemount report which justifies a 24-month interval'is included as '
Attachment 1.
- 3. Provide additional details on the impact of sensor calibration frequency of your justification of extended instrument surveillance intervals, which was based on maintaining current functional test. intervals. -
Response ,
Our request for extending sensor calibration intervals is not based on functional test intervals. We did, however, use the fact that some trip devices are checked at intervals of less than 18 months in order to extend their calibration interval. The functional test on these devices checks and recalibrates the device setpoint, if necessary.
- 4. Verify that plant procedures for the affected instrumentation have been reviewed and verified to reflect the adopted GE setpoint methodology.
(That is, verify that the surveillance procedures acceptance-criteria design basis is consistent with the GE setpoint methodology).
Response
The surveillance procedure acceptance criteria' are consistent with the methodology used to originally determine the setpoint. This method, as i pre,'iously discussed, is not comparable to the GE setpoint methodology. l A design review was completed during the 1987-1989 PBAPS shutdown and the acceptance criteria were confirmed to be consistent with the plant design. ;
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- 5. The application of October 19, 1992, confirms that a historical review was performed for surveillance tests (ST) results. Confirm that this historical review included an evaluation of any applicable maintenance ;
records. (e.g., corrective maintenance, INPO reports, etc.)
Response
The historical review included an evaluation of applicable maintenance records and Operating Experience Assessment Program (0EAP) data.
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- 6. Describe the application of the GE methodology to instrumentation l installed at Peach Bottom that was not evaluated in GE topical NEDC- l 31336. (e.g., moduflash 652) 1
Response
We used the drift determination section (4.4.3) of the GE methodology with the following modifications: the difference between the as-left '
value of one calibration to the as-found value of the'next calibiation was treated as drift. This modification is conservative because .
. uncertainties (e.g., temperature effects, calibration equipment, calibration procedures) associated with the setpoint were not removed.
The GE drift methodology is independent of instrument type, manufacturer or setpoint methodology.
- 7. For main steam temperature resistance temperature detectors, it is stated that these devices are factory calibrated devices and do not exhibit drift. Provide surveillance test results, applicable vendor information and qualification data to verify the limited drift of these devices. Is sensor drift considered in uncertainty calculation? i
Response
The physical features of RTDs provide for a high degree of stability in that they are completely passive, have no active components and have a service life of 40 years. Our experience has shown that RTDs fail for reasons other than calibration shift. We are cognizant of the present activity in the industry dealing with cross calibration of RTD in PWRs and the controversy over the magnitude of the various errors.
There is sufficient margin (i 0.2 C) in the ST allowable value for main steam temperature, to accommodate for the aging of RTDs and for a thirty month calibration frequency (NUREG-5560, June 1990, Aging of Nuclear '
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Plant Resistance Temperature Detectors).
- 8. What is the model number for the Foxboro microcomputer referenced in the submittal for reactor level monitoring. Is it a Foxboro spec 200 micro .
system?
Response
The Foxboro spec 200 micro system is used to monitor reactor water level on both units at the Peach Bottom Atomic Power Station.
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- 9. In your application, you described that the safety relief valve positior, switch evaluation would not support an extended surveillance interval.
The switch position switch data was found to be consistently in the conservative direction with regards to flow. However, based on the conservative direction of the position switch the drift, the evaluation recommended a 24-month interval. Provide the plant-specific drift results and additional justification as to why the as-left and as-found drift value has not been incorporated into the current calibration surveillance and setpoint determination.
Response
Attachment 2 is made up of two tables:
Table 1 is the results of the drift trending analysis. The analysis shows that the mean value for the observed in service difference (0ISD) is negative except for the interval-of 45 months. Interpolation of the area between the interval for 25 and-45 demonstrates that the 30 month interval will also have a negative OISD.
Table 2 is a listing of the Peach Bottom "as-found" and "as-left" data that were used by the General Electric Drift Trending Analysis program.
We have not incorporated the results of the trending analysis into our evaluation because our review of the data revealed:
- 1. Of the 121 data points taken, seven data points were l significantly outside of calibration. These seven data points skewed the trending analysis so much that the results were unacceptable. Without these data points the trending analysis would have been acceptable. Of these'seven data points, six were found on PBAPS Unit 3 and one was.found on.
PBAPS Unit 2.
- 2. The seven points where taken during surveillance tests ~ ren in November, 1990.
- 3. Removal of this data from the analysis yields result within the acceptance criteria.
- 10. For the referenced digital feedwater modification, provide information on any changes to setpoint calculations, etc., that were required to incorporate any revised instrument uncertainties. Provide results of the revised setpoint calculations or any vendor recommendations on surveillance requirements or additional analysis to support the proposed extended surveillance intervals.
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- Response The setpoint for the Rod Block Monitor (RBM) was changed. The new setpoint was determined in accordance with our design calculations procedures. The Leeds and Northrop transmitters were replaced with Rosemount transmitters. The new Rosemount transmitters provide greater accuracy and less uncertainty. The setpoints for these new instruments were revised to reflect the decrease in uncertainty.
- 11. For the suppression pool water temperature instrumentation provide information on surveillance testing and qualified life of this instrumentation. Does a specified replacement schedule exist for the thermocouples?
Response
The qualified life of the suppression pool temperature detectors is 40 years; therefore, there is no specific replacement schedule.for these RTDs. During surveillance testing of the RTDs the operability and functionability of the RTDs are determined.
- 12. The drywell pressure instrumentation drift analysis results represent only an 18-month value. Provide details as the method of determining the 30-month drift term based on the limited data set of the drift study. Also confirm that a surveillance history evaluation was performed on the plant as-left and as-found drift data. No assessment of instrument availability was presented in the submittal. Provide details on the stated change in calibration method for drywell instrumentation.
Response
The GE program was able to calculate an estimated 18-month drift number.
This estimated drift number is less than one-half of the allowable drift value. Therefore, based on the small drift number as compared to the allowable and the fact that the review of testing before the 1987-1989 shutdown showed that the switches did not need recalibration from the time they were installed in 1983, we conclude that the present allowance will be more than sufficient for the additional seven and half months between surveillance tests.
Since these devices have not had a concern in the past, as verified by both surveillance history and equipment history, we do not expect device availability to change with a 24 month refuel cycle.
The changes to the surveillance testing were mainly in the order of performing steps, points where the values where taken, and the number of data points taken.
- 13. The instrumentation for the seismic monitoring is new and thus, plant-specific information is not available (for Kinemetrics). The submittal indicated that the vendor has certified that a surveillance interval of 30-months is acceptable for this instrumentation. Provide a summary or a copy of vendor documentation (Kinemetrics and Engdahl).
Response
The Engdahl seismic monitors installed at PBAPS are the same models that are installed on the reactor vessel head at Limerick Generating Station (LGS). PECo requested that the calibration interval for the reactor head seismic monitors at LGS be extended to accommodate a 24 month fuel cycle on May 15, 1992. The request was approved by the NRC on August 20, 1992. Attachment 3 is a copy of the Kinemetrics letter.
- 14. Describe the changes in calibration test methods (drift) for the seismic monitoring information manufactured by Engdahl.
Response
The surveillance requirements for the Engdahl seismic monitors have an acceptance requirement to compare previous test results with present test results.
- 15. Has the revised plant as-left and as-found drift term been incorporated into the uncertainty calculation or surveillance procedure for the main l turbine control valve fast closure pressure switches? Has the as-left and as-found drift value been evaluated for a 30-month surveillance-interval? l l
l Response j l
PECo has not incorporated the revised as-found and as-left drift term, l which has been calculated for 30 months, into the uncertainty calculation for the surveillance procedure for the main turbine control valve (MTCV) fast closure pressure switches. The reason why this has not been done is two-fold. First, PECo has determined that the impact of the calculated drift of the subject instrument on the accident
- analysis is insignificant, since it would result in 2 to 3 milliseconds :
of added response time when there is typically a margin of approximately !
Y 100 milliseconds in the total response time for i.his function. Second, PECo believes the cause of the drift of these instruments.is related to I
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pressure oscillations and vibration of the process. At LGS, Unit 1, two modifications were performed on the Electro Hydraulic Control (EHC) system to eliminate the drift on these instruments. These modifications (which yielded significantly lower drift values, for the last 18 month fuel cycle) first moved the subject pressure. instruments from the MTCV valve pack to an adjacent support beam, and installed additional accumulators in the EHC system. By moving the instruments to the beam, the effects of system vibration were minimized. The additional accumulators in the EHC system dampen out EHC system pressure oscillations. These two modifications have not yet been installed at any other PECo units.
Based on the above discussion, PECo is requesting for both PBAPS.and LGS to have the calibration frequency for the MTCV fast closure pressure switches euended from 18 months to 24 months. A setpoint adjustment 'is not necessary at this time and a more prudent course of action is to correct the cause of the drift. Finally, based on the above discussion, PECo has determined that going to a 24 Month calibration frequency on these subject instruments will have a negligible impact on safety.
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- 16. Provide details on the relationship of the drift of Magnetrol switches at Limerick Generating Station to the instrumentation at Peach Bottom and the applicability to a 30-month surveillance interval extension.
(Robertshaw and RCI (FCI?) installed at Peach Bottom). Was manufacturers drift data considered in the evaluation of an extended interval?
Response
The test procedure for the Robertshaw and FCI switches is a "go, no-go" -
test, that determines whether the switches are activated at any value below 50 gallons; therefore, no as-found data is recorded to serve as the basis for a drift value. The test adequately assures the Scram Discharge Volume (SDV) can receive the Control Rod Drive (CRD) charging water without hydraulic interference. It should be noted the switches are FCI switches.
- 17. Provide documentation _to support a 24-month surveillance interval for proposed "NUMAC" main steam line radiation monitors. (GE publication, .
test results, or revised uncertainty calculations.) l 1
i c
Response
GE provided a letter to PECo which specifies the drift for the subject NUMAC radiation monitors. Since the drift number falls within the l allowance of the current instruments, no changes were necessary to the l current setpoint calculation or the uncertainty factor. The GE letter 1 is provided as Attachment 4. I
- 18. Since the main steam line radiation monitors were not replaced for Unit 2 in the September 1992 outage, will the original equipment be operating on a 24-month interval? Provide additional details to justify the apparert surveillance interval increase for existing instrumentation for both Units 2 and 3.
Response
The NUMAC instrumentation was not installed during the Fall 1992 Unit 2 refuel outage. The existing instrumentation is adequate for a 24 month fuel cycle because quarterly and weekly surveillance tests calibrate and functionally check the operation of the instrument. The sensor (an ion chamber) is not checked during these test; however, ion chamber detectors are not considered to be susceptible to drift. Further, the readout of these instruments is monitored by station personnel, and any deviation greater than +100 mR/hr/-200 mR/hr will require action from the plant staff.
- 19. Provide details on the evaluation of electromagnetic interference and radio frequency interference compatibility, susceptibility, emission, and site survey for the NUMAC radiation monitors.
Response
As was discussed during the May 10, 1993 telephone conversation, the design for the modification to install the NUMAC instruments adequately evaluated electromagnetic interference and radio frequency interference.
The details of this evaluation are available for your review.
- 20. The drywell radiation monitoring system drift evaluation contained insufficient data points to develop a 30-month drift term. Is additional data available to support an extended surveillance interval (vendordata,similarsystems)?
- Response Additional data are not available to support an extended surveillance interval. The same model is not used in other systems at either PBAPS or LGS and the vendor was not able to produce a 30 month drift value without conducting a listing program. Sufficient justification for extending the surveillance interval exists because of the following:
- 1. The readouts of these instruments are recorded by plant operators during their rounds and any deviations greater than
-1 R/hr/ + 10R/hr or a change of greater than 3 R/hr between readings will require further action by plant staff. t
- 2. The drywell radiation monitors provide a signal to alarms in the control room, which alert station personnel to malfunctions in the system.
- 3. The monitors did not require to be recalibrated from 1988 to 1991; except for those monitors that were replaced after control room alarms indicated a malfunction.
- 21. The safety discussion on page 10 of the October 19, 1992, application states that the calibration surveillance interval for the torus to Reactor Building vacuum breaker instrumentation will remain unchanged at 18 months (proposed TS 4.7.A.3a). However, at the bottom of page 10, you state that the GE methodology drift analysis on the Torus to Reactor Building Pressure switches (TS 4.7.A.3.a) demonstrated the surveillance j interval could be extended to 24 months. Please clarify and rejustify your intentions with respect to TS 4.7.A.3.a.
Response
The torus to Reactor Building vacuum breaker instrumentation loop ,
consists of several components. An analysis using the GE methodology ,
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was done on extending the interval to 24 months for each of these components. Sufficient justification to extend the interval could et be developed for all of the components, so we elected to keep the interval for the entire instrument loop the same. In our submittal, we did not fully explain this distinction.
- 22. For scram discharge instrumentation, the submittal references failed switches that had to be replaced. Were failed switches found during calibration or functional tests? Is the functional test similar to the '
calibration surveillance?
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Response
The one failed test occurred in 1985 while perfonning a calibration test. The functional test and the calibration test are the same test.
B. Non-Instrument Related Questions
- 23. TS 4.5.C.1.a requiring a once-per-operating-cycle Simulated Automatic Actuation Test does not appear to be addressed in the September 28, 1992, submittal; however, the surveillance interval for this test will be changed by a change to the TS Definition of "Once-per-Cycle." Please justify extenrhng this TS interval or provide a specific frequency for l this TS item,
Response
The identified concern is an oversight by PECo in the preparatinn of the 24 Month Cycle Project scope. After review of the methodology utilized to verify the scope of the 24 Month Cycle Project, it was identified that this line item would not have been specifically identified. The weakness in the verification methodology is considered unique to this situation, and it is PEco's position that this one oversight does not invalidate the determination of the scope.
This line item, although not specifically identified in the subject transmittals, is essentially the same as the other Simulated Automatic Actuation Tests performed on systems such as Core Spray, Reactor Core Isolation Cooling (RCIC), and Residual Heat Removal (RHR) which were.
justified in the subject transmittals. In fact, the procedure utilized to perform this surveillance test, is used to perform other similar surveillance requirements. Based on the above discussion, it is PECo's position that the addition of this line item does not represent a major change to the subject transmittals, and the change is supported by the evaluation currently contained in the transmittals.
- 24. In Section (2) " Air" of the September 18, 1992, submittal, you describe other STs that quantitatively identify leakage rate of the safety grade pneumatic supply system. Describe the performance and frequency of these STs or reference the corresponding TS requirements.
Response
The other STs that quantitatively identify leakage rate of the safety grade pneumatic supply system, are part of the In Service Testing (IST) program. The check valves which prevent back leakage, are part of the scope of the PBAPS IST program, and are classified as Category "A" valves. As a Category "A" valve, these check valves are required to be leak tested every 2 years. Currently, these valves are tested on a Refueling basis or during Cold Shutdown when the containment is deinerted.
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- 25. A safety evaluation dated July 2, 1984, addressed implementation of.
functional testing requirements. It stated that "In order to provide L assurance that the hydraulic and mechanical snubbers function reliably, a representative sample of the plant's installed snubbers will be functionally tested at least once-per-18 months during plant shutdowns.
The required sampling provides a confidence level of 95% that 90% of the plant-specific snubbers will be operable within acceptable limits."
Although GL 91-04 does not require licensees to quantify the effect of changing the surveillance interval, your application of September 28, 1992, did not make reference to any evaluation of previous ST results in justifying an extension of the surveillance interval. The lack of preventative maintenance performed on a component is not an adequate justification for extending the surveillance interval. Provide justification for extending the snubber functional inspections interval in TS 4.11.D.4.
Response
Although not specifically identified in the subject transmittal, PECo performed a review of the snubber failures. This review examined all failures in the past 10 years of surveillance tests. It was identified, that although there have been problems / failures of snubbers, no failures have resulted in the inoperability of the piping which the snubbers were supporting. Based on this historical review, it is the conclusion of PECo that the change from 18 to 24 Month cycles will have a small, if any, impact on the availability of the piping system, since the piping system in most cases will still function without certain snubbers.
Three additional request were presented during a May 10, 1993 telephone conversation between'the NRC and PECo. These requests are restated below along with our response.
- 26. State your intention regarding TS surveillance requirement 4.5.G.2.
Response
For Technical Specification 4.5.G.2, it is requested that the subject surveillance requirement be changed from the current 18 month frequency to a 24 month frequency. This TS line item was listed in our TSCR; however, additional clarification is being provided. The basis for this change is that currently there are quarterly functional tests which check the setpoint of these instruments. The quarterly functional tests are an NRC commitment, and perform the same function as the 18 month calibration test.
- 27. What does functional test 4.1.D.2 do s and why is it a basis for extending the calibration frequency.
Response
The functional test for checking the Reactor Protection System (RPS) alternate feed relays (TS 4.1.D.2.) includes a calibration check of the relays. The functional test is completed every six months.
- 28. State your intention for Table 4.1.2, Item 13, Note 5, Main Turbine Stop Valves
Response
The Turbine Stop Valve (TSV) Closure, Table 4.1.2, Item 13, Note 5 is to be included in our request for a TS amendment. In our earlier submittals, a full justification for extending the surveillance was not clearly presented.
The limit switches associated with the TSV provide input to reactor scram logic and also provide valve position indication. Functional testing on the TSVs is provided on a more frequent basis than every 18 months. This functional testing consists of cycling one of the TSVs from the open position to a specified percent closed position, and back .
to the open position. A different valve is cycled each time the functional test is performed. Confirmation that the switch is operating properly is done by observing the position indicating lights when the valve opens and closes. Since functional testing to confirm proper valve and limit switch operation is performed more frequently than every 18 months, an increase in the surveillance interval to accommodate a 24 month fuel cycle does not affect the limit switches with respect to dri f t. Note, for the limit switches which are mechanical devices, misalignment is a more applicable term than drift.
Several additional concerns have been discussed in conversations between the NRC and PECo. These concerns are restated below along with our response.
- 29. The NRC requested clarification on the TS requirement Table 4.2.A, (1 tem 1-5) Note 4, Primary Containment Isolation System (page 16 of the September 28, 1992 submittal) and Table 4.2.8 Item 1-8, Note 4, Core Standby Cooling System (CSSC) (page 17 of the September 28, 1992 submittal).
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Response
The analysis for these items was meant to address the Note 4 requirement to perform a Simulated Automatic Actuation Test and not a Logic System Functional Test.
- 30. The NRC was concerned that TS 4.9.C.4, which was a new requirement
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approved by the NRC on September 16, 1992, was not analyzed for a 24 month fuel cycle, ,
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Response
The new TS requirement was requested on January 10, 1992 and approved on September 16, 1992. The requirement concerns a once per refuel outage inspection of the Emergency Service Water (ESW) pump bay. While not explicitly clear in our January 10, 1992 application, the analysis and proposed requirement were intended to be performed on a 24 month fuel cycle.
The NRC expressed concerns with our performance and service tests of our 31.
batteries. In specific, with the loading profiles for the first 10 minutes of our service test.
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Response
Peach Bottom currently performs a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> service test on the batteries ,
with the following loading profiles.
Battery 0 -1 min. 1 - 120 min >
2A & 2C 233.4A 122.2A 2B & 2D 915.4A 226.4A The U2 loading profiles were provided because they are more severe because of common plant equipment being fed from U/2 batteries. In addition, each cell is scanned for hot spots midway through the test.
A four hour performance tested is completed at 360 Amps; again each cell .
is scanned for hot spots midway through the test. It should be noted !
that the battery chargers are reenergized at 17 seconds during the current PBAPS design. 3 i
PECo believes that because of the performance trending, thermography, and visual inspection the station batteries will deliver the required current during an accident. In addition, PEco has committed to implementing the Improved Technical Specifications, which will satisfy the battery testing criteria.
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