IR 05000266/1985018
| ML20137Z883 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 10/02/1985 |
| From: | Mccormickbarge, Ring M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20137Z869 | List: |
| References | |
| 50-266-85-18, NUDOCS 8510080398 | |
| Download: ML20137Z883 (8) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Report No. 50-266/85018(DRS)
Docket No. 50-266 License No. DPR-24 Licensee: Wisconsin Electric Power Company 231 West Michigan Milwaukee, Wisconsin 53203 Facility Name:
Point Beach, Unit 1 Inspection At:
Two Creeks, Wisconsin Inspection Conducted:
September 9-13, 1985
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M. L. Mc ormick-arger
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Approved By:
Test Programs Section Date Inspection Summary Inspection on September 9-13, 1985 (Report No. 50-266/85018(DRS))
Areas Inspected:
Routine, announced inspection to review licensee procedures and results in the areas of core power distribution limits, control rod worth measurements, axial flux difference measurements, core thermal power calculation and isothermal temperature coefficient measurement.
The
' inspection involved 35 inspector-hours onsite.
Results:
No violations or deviations were identified.
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8510080398 851002 PDR ADOCK 05000266 G
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DETAILS 1.
Persons Contacted
- J. J. Zach, Point Beach Nuclear Plant Manager
- J. E. Knorr, Regulatory Engineer, Engineering Quality and Regulatory Services (EQRS)
- J. C. Reisenbuechler, Superintendent, EQRS
- F. A. Flentje, Administrative Specialist, EQRS R. L. Harris, Superintendent, Reactor Engineering P. N. Kurtz, Engineer, Nuclear Reactor Engineering N. L. Pitterle, Engineer, Nuclear Reactor Engineering R. D. Mitchell, Shift Superintendent Additional station technical and administrative personnel were contacted by the inspector during the course of the inspection.
- Denotes those personnel present at the exit interview.
2.
Core Power Distribution Limits Tae inspector reviewed licensee procedures and results to verify that vo. lues for quadrant power tilt, enthalpy rise hot channel factor, and heat flux hot channel factor were within acceptance criteria and consistent with Technical Specifications, and that any discrepancies were properly evaluated.
The inspector utilized the following documents during the review:
Wisconsin Michigan Test Procedure (WMTP) 5.3, Major,
Revision 4, March 30, 1984, " Power Level Increase to Full Load," performed for Unit 1 Cycle 13 on June 28, 1985 to September 5, 1985.
WMTP 6.1, Major, Revision 2, June 21, 1985, " Core Power
Distribution and Nuclear Power Range Detector Calibration Checks," performed for Unit 1 Cycle 13 on July 1-3, 1985.
WMTP 9.2, Major, Revision 12, January 25, 1985, " Nuclear
Power Range Detector Calibration Quarterly Axial Offset Test," performed for Unit 1 Cycle 13 on June 24, 1985, to July 1, 1985.
Point Beach Flux Maps (PBFM):
113-9, July 1, 1985, First flux map at 100% power for Unit 1 Cycle 13 113-10D, August 2, 1985 113-15C, September 5, 1985
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Letter from W. J. Johnson, Westinghouse Electric
Corporation, to J. J. Zach, Point Beach Nuclear Plant Manager, " Westinghouse Position Statement on Core Tilt," WEP-82-582, dated November 10, 1982.
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Letter from T. R. Croasdaile, Westinghouse Electric
Corporation, to R. A. Newton, Wisconsin Electric Power Company, " Unit 1 Cycle 13 Startup Quadrant Tilt,"
85WE*-G-070, dated September 12, 1985.
a.
Quadrant Power Tilt Except during physics tests, the Technical Specification 15.3.10.B.3 limit on quadrant power tilt is 2%.
For the purposes of comparing to this limit, the power tilt may be considered to be the power tilt measured by the incore detectors less any core tilt that has been factored into plant accident analyses.
Flux Map 113-9 indicated that the measured power tilt was 1.0239 (i.e., 2.39%) at
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100% power.
During discussions with the licensee, the licensee stated that, based on informal conversations with a Westinghouse representative, about 1% core tilt was anticipated.
This 1% was sufficient to encompass the.39% excess.
However, as a result of the inspector's request for documentation of the core tilt value, the licensee requested and received documentation from Westinghouse which stated that the core tilt value used in the core reload safety analysis was only 0.4%.
This just barely encompasses the.39%
excess tilt measured.
The inspector was concerned that the quadrant power tilt evaluation was based on unsubstantiated information and recommended to the licensee that data supplied by vendors as the basis for establishing technical specification compliance be verified in writing.
To verify that the quadrant power tilt remained within acceptable limits subsequent to Flux Map 113-9, the inspector reviewed Flux Maps 113-100 (dated August 2, 1985) and 113-15C (dated September 5, 1985).
The measured power tilt was less than 2% (1.62% and 1.51%,
respectively) for each of these maps.
b.
Enthalpy Rise and Heat Flux Hot Channel Factors The inspector reviewed the maximum measured values of the enthalpy rise and heat flux peaking factors from Flux Map 113-9 and found that both were within technical specification limits.
The test results for WMTP 9.2 discussed the fact that many fuel rods had differences between measured and predicted enthalpy rise peaking factor values that exceeded the test review criteria of 15%; the maximum difference was 7.493% as indicated on the hot zero power flux map.
The evaluation stated that the differences observed were partially because the computer analysis assumed full power equilibrium xenon conditions which did not exist for the flux
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maps taken during the startup testing and partially because of the lack of symmetry in the core.
The evaluation also stated that the enthalpy rise peaking factor would be monitored as the cycle progressed.
The inspector had no concerns with the licensee's course of action regarding this matter.
No violations or deviations were identified.
3.
Control Rod Worth Measurements i
The inspector reviewed licensee procedures and results to verify that i
control rod worths were within acceptance criteria and consistent with
Technical Specifications, and that any discrepancies were properly evaluated.
The inspector utilized the following documents during the review:
Wisconsin Michigan Test Procedure (WMTP) 4.2, Major,
Revision 3, dated March 30, 1984, " Control Bank A Worth and Endpoint Measurement, and Temperature Coefficient Measurement with Bank A Inserted," performed for Unit 1 Cycle 13 on June 18-19, 1985.
WMTP 4.3, Major, Revisiori 3, dated March 30, 1984, " Rod
Worth Measurements by Swap Method," performed for Unit 1 Cycle 13 on June 19, 1985.
Reactor Engineering Instruction (REI) 20.0, Minor,
Revision 2, dated June 14, 1985, " Control Rod Worth and Endpoint Measurement Instructico."
REI 10.0, Minor, Revision 3, dated November 30, 1984,
" Reactivity Computer Instruction."
Westinghouse Report WCAP-10799, "The Nuclear Design and
Core Management of the Point Beach Unit 1 Nuclear Reactor Cycle 13," dated May 1985 - Table A.3, " Required Data for Rod Exchange Test."
Letter from A. Schwencer, Nuclear Regulatory Commission,
to S. Burstein, Wisconsin Electric Power Company, " Acceptance and Review Criteria for Rod Swap Testing," dated October 12, 1978.
The inspector compared the design values for integral bank worth for each shutdown bank and control bank with the measured values based on results of WMTP 4.2 and WMTP 4.3 and noted that all acceptance and review criteria related to integral rod bank worths were met.
The inspector also reviewed the strip chart associated with rod worth for Control
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Bank A (CBA) and calculated a value of approximately 1495 pcm for CBA from 1 step to 206 steps which was in good agreement with the value calculated by the licensee of 1494.2 pcm.
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The inspector was not able to independently calculate CBA worth from 209 steps to 217 steps because the licensee was not able to locate the strip chart for this portion of CBA.
The licensee believed that this portion of the strip chart was inadvertently cut off the end of the strip chart and discarded.
Since the licensee read reactivity values (reactivity is the measure of rod worth) from the strip chart while the test was in progress, a handwritten sheet of values of reactivity per step for CBA from 209 to 217 steps was available.
The inspector estimated the worth of the portion of CBA from 209 to 217 steps using differential worth data at 209 steps (approximately 9 pcm/ step) and at 217 steps (approximately 5.3 pcm/ step).
This resulted in a bank worth value of approximately 57.1 1 14.9 pcm which compared favorably with the licensee's handwritten data sheet value of 56.4 pcm.
The situation in which the licensee was unable to retrieve the strip chart for Control Bank A worth from 209 to 217 steps was judged by the inspector to have minimal safety significance.
However, the inspector reminded the licensee of the need to ensure that test data is appropriately documented and that retrievable records are maintained.
No violations or deviations were identified.
4.
Target Axial Flux Difference Measurement For Unit 1 the Cycle 13 Technical Specifications were changed such that the licensee was no longer required to calculate a target band for the axial flux difference.
As a result of this change, the need to calculate penalty minutes was also eliminated.
Instead, a Flux Difference Operating Envelope was provided in Technical Specification Figure 15.3.10-4 and per Technical Specification 15.3.10.B.2.b, "If the indicated axial flux difference (AFD) deviates from the Figure 15.3.10-4 limits, the AFD shall be restored to within the Figure 15.3.10-4 limits within 15 minutes.
If this cannot be accomplished, then reactor power shall be reduced until the AFD is within the envelope or the power level is less than 50 percent of Rated Power." The inspector reviewed the axial flux difference (delta flux)
values recorded on the Unit 1 Control Room Shift Logs for July 1985 and noted that the values were within the limits of the Technical Specification Figure 15.3.10-4 operating envelope.
During the review the inspector observed that the following note on the Unit 1 Control Room Shift Logs was applied to the delta flux measurements:
Note 14 - Delta flux shall be maintained within a range of +6 or -9 percent of the target delta flux.
This note was not valid since, for Unit 1 Cycle 13, a target delta flux is no longer calculated.
Additionally, per Technical Sr.ification Figure 15.3.10-4, the most limiting axial flux difference limits exist between 90 to 100% power and at these power levels the delta flux limits are +5 to -13% delta flux.
During a discussion of this matter with the licensee, the licensee stated that the Control Room Shift Log would be updated to correct Note 14.
This is an open item (266/85018-01(DRS))
pending revision of the log and subsequent NRC review.
The licensee also stated that the appropriate delta flux limits for power levels from 90 to 100% power (i.e., +5 to -13% delta flux) were identified
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directly above the delta flux instrument readout in the control room.
The inspector confirmed this during a brief tour of the control room.
No violations or deviations were identified.
However, a portion of this area requires further review and evaluation and is considered to be an open item.
5.
Core Thermal Power Calculation The inspector reviewed the following documentation in the course of the review of the licensee's method of calculating core thermal power:
" Heat Balance Results" as recorded on the Unit 1 Control Room Shift Log for July 1, 1985, through July 31, 1985, inclusive.
Wisconsin Michigan Test Procedure (WMTP) 5.2, " Reactor
Engineering Tests During Escalation to 90% Power,"
dated March 30, 1984, and performed for Unit 1 Cycle 13 on June 21-28, 1985.
WMTP 9.18, Major, Revision 6, " Precision Reactor Coolant
System Flow Rate Measurement with Operating State Data Collection," dated April 26, 1985.
Reactor Engineering Instruction (REI) 1.0, Minor,
Revision 7, " Power Level Determination," dated May 17, 1905.
REI 2.0, Minor, Revision 5, " Power Range Detector
Power Level Adjustment," dated August 5, 1983.
REI 17.0, Minor, Revision 12, " Backup Methods for
P-250 Computer Monitoring Functions," dated June 7, 1985.
Unit 1 Control Room Shift Logs for July 1985 were reviewed to ensure that reactor power level was within prescribed limits.
The power level data on the hourly computer logs for July 4, 9, 15, 17, 29, and 31 were also reviewed.
There were no concerns as a result of this review.
The inspector asked to review either heat balance procedure test results or a computer printout showing the details of a heat balance for a typical core thermal power calculation for Unit 1 Cycle 13.
The licensee explained that a control room operator simply requests the value for the heat balance from the process computer and records the output value on the Control Room Shift Log.
Therefore, there weren't any additional records which would show the details of the heat balance.
When the inspector asked to review an independent calculation of the process computer heat balance, the licensee explained that the computer calculation was checked when it was first developed and, subsequently,
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whenever a change to the computer software was made.
Any other independent checks were considered optional.
For instance, WMTP 5.2 contained a step which' stated, "The secondary side readings (if taken)
should appear reasonable." This optional step was not performed for the Unit 1 Cycle 13 startup.
The licensee stated that WMTP 9.18 could be used as an independent check of the process computer heat balance
~ calculation.
However, it was not used for that purpose at the time of the inspection.
The inspector performed an independent calculation of core thermal power using data from the hourly computer log sheets at 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br /> on July 9, 1985.
The result of the inspector's calculation was within satisfactory agreement of the result calculated by the process computer.
No violations or deviations were identified.
6.
Isothermal Temperature Coefficient Measurement The inspector reviewed licensee procedures and results to verify that results obtained were within acceptance criteria and consistent with Technical Specifications, and that any discrepancies were properly evaluated.
The inspector utilized the following procedures during the review:
Wisconsin Michigan Test Procedure (WMTP) 4.1, Major,
Revision 4, dated November 30, 1984, " Initial Criticality, All Rods Out Flux Map, Endpoint, and Temperature Coefficient Measurements," performed for Unit 1 Cycle 13 on June 18-19, 1985.
Reactor Engineering Instruction (REI) 21.0, Minor,
Revision 2, dated June 14, 1985, " Hot Zero Power Temperature Coefficient Measurement Instruction."
As part of the core reload analyses, predicted values of the isothermal temperature coefficient (ITC) and moderator temperature coefficient (MTC)
were calculated.
According to the predictions, the MTC would be negative for power levels greater than 70% power as required by Technical Specification 15.3.1.F.2 and would be less than +5 pcm/ F whenever the reactor was critical as required by Technical Specification 15.3.1.F.1.
Based on the assumption that, if the predictions are correct, MTC technical specification limits would be satisfied, the licensee verified the adequacy of the predictions by measuring the isothermal temperature coefficient at the hot zero power all rods out condition.
TheITCvaluemeasured(-3.8pcm/F)waswithinthedesignacceptance criterion of 3 pcm/ F of the predicted value (-2.5 pcm/ F).
The inspector had no concerns as a result of the isothermal temperature coefficient review.
No violations or deviations were identified.
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7.
Open Items Open items are matters which have been discussed with licensee which will be reviewed further by the inspectors, and which involve some action on the part of the NRC or licensee or both.
An open item disclosed during the inspection is discussed in Paragraph 4.
8.
Exit Intervew The inspector met with licensee representatives denoted in Paragraph 1 at the conclusion of the inspection on September 13, 1985.
The inspector summarized the scope of the inspection and the findings.
The inspector also discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the inspector during the inspection.
The licensee did not identify any such documents /
processes as proprietary.
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