IR 05000304/1982011
| ML20054L024 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 06/21/1982 |
| From: | Jackiw I, Robinson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20054L022 | List: |
| References | |
| 50-304-82-11, NUDOCS 8207070080 | |
| Download: ML20054L024 (6) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Report No. 50-304/82-11(DETP)
Docket No. 50-304 License No. DPR-48 Licensee: Commonwealth Edison Company P.O. Box 767 Chicago, IL 60693 Facility Name:
Zion Nuclear Power Station, Unit 2 Inspection At:
Zion Site, Zion, Illinois Inspection o ted: May 12-14, 1982
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me5*ms Inspector.
L. Robinson b> * b ' b I'
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Approved By:
. N.
ackiw, Chief est.'rogram Section
~5 ~ I 2-Inspection Summary Inspection on May 12-14, 1982 (Report No. 50-304/82-11(DETP))
Areas Inspected: Routine, announced inspection of Unit 2, Cycle 6 control rod drop time tests; control rod drive and position indication checks; reactor thermocouple /RTD cross calibration; incore/excore calibration; control rod worth measurements; reactor shutdown margin determination; isothermal temperature coefficient measurement; power coefficient of reactivity measurement; target axial flux difference calculation; core thermal power evaluation; core power distribution limits; determination of reactivity anomalies. The inspection involved a total of 12 inspector-hours onsite by one NRC inspector including 0 inspector-hours onsite during off-shifts.
Results: No items of noncompliance or deviations were identified.
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DETAILS 1.
Persons Contacted
- K. Graesser, Station Superintendent
- T. Miosi, Technical Staff Supervisor
- P. LeBlond, Assistant Technical Staff Supervisor
- W. T'Niemi, Nuclear Group Leader T. Printz, Thermal Group Leader
- R. Chin, Nuclear Engineer
- B. Harl, Quality Assurance Supervisor
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- J. Waters, NRC Senior Resident Inspector
- J. Hinds, Jr., NRC Project Inspector
- Denotes those present during the exit interview.
2.
Verification of Conduct of Startup Physics Testing The inspector reviewed the startup physics testinr,for Zion 2 Cycle 6 and verified that the licensee conducted the following:
a.
Rod Drive and Rod Position Indication Checks b.
Reactor Thermocouple / RID Cross Calibration c.
Core Power Distribution Limits d.
Incore/Excore Calibration e.
Core Thermal Power Evaluation f.
Determination of Reactor Shutdown Margin g.
Isothermal Temperature Coefficient h.
Power Coefficient of Reactivity Measurement 1.
Control Rod Worth Measurement j.
Target Axial Flux Difference Calculation k.
Determination of Reactivity Anomalies 3.
Control Rod Drive and Position Indication Checks The inspector reviewed the results of surveillance procedure T.S.S.
15.6.26, " Control Rod System Che:kout", dated November 4, 1981 for
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Zion 2 Cycle 6 and concluded that all rod drop times satisfied the acceptance criteria of 1.8 seconds or less required by the Technical Specifications. The inspector also verified that rod drive and rod position indication checks were performed as part of the surveillance on November 26, 1981.
No items of noncompliance or deviations were identified.
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4.
Reactor Thermocouple /RTD Cross Calibration The inspector reviewed information related to reactor thermocouple /RTD cross calibration as described in surveillance procedure T.S.S. 15.6.72,
"RTD Cross Calibration," dated November 10, 1981. The inspector noted
that three narrow range RTDs were outside the licensee's acceptance criteria, deviating by more than 0.5'F from the RTD average. The inspec-tor verified that these three narrow range RTDs were adjusted, the wide range RTDs and reactor thermocouples tested, and all applicable Technical Specifications satisfied. The inspector noted that the licensee had not established criteria to evaluate the wide range RTDs and that 22 of the 65 incore thermocouples were inoperable.
The licensee stated that although the loss of incore instrumentation was undesirable, the remaining thermo-couples were sufficient to monitor core conditions.
No items of noncompliance or deviations were identified.
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5.
Incore/Excore Detector Calibration The inspector reviewed information related to incore/excore detector calibration as described in surveillance procedure T.S.S. 15.6.2,
"NIS Calibration," dated June 1, 1978. The inspector reviewed the graphs of incore axial offset versus excore axial offsets for the four power range channels and noted that the calibration currents were properly obtained for the upper and the lower excore detectors.
The inspector determined that the licensee had satisfied the Technical Specification requirement to calibrate the nuclear power range channels every three effective full power months.
No items of noncompliance or deviations were identified.
6.
Control Rod Worth Measurement The inspector reviewed information related to the Zion 2 Cycle 6 determination of control rod worths as described in surveillance procedure, T.S.S. 15.6.55, " Rod and Boron Worth Measurements," dated March 19, 1981. The reactivity of the reference bank (Bank D) was measured using the boration/ dilution technique and the reactivity worth of the remaining banks was inferred using rod swap reactivity comparisons to the reference bank. The inspector concluded that the results of the rod swap procedure satisfied all acceptance and review criteria as outlined in a February 4, 1981 letter from J. S. Abel (CECO) to H. R. Denton (NRR). The difference between measured and predicted integral worth for the reference bank was approximately 4%.
The maximum difference between the inferred and predicted in-tegral worths for all other banks was approximately 8%.
The difference between the sum of the measured / inferred bank worths and the sum of the predicted worths was approximately 6%.
The inspector noted that the licensee received NRR approval to use the rod exchange technique in a letter from S. A. Varga (NRR) to J. S. Abel dated March 1,23 1981.
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No items of noncompliance or deviations were identified.
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7.
Determination of Shutdown Margin The inspector reviewed information related to an analytical determin-ation of Cycle 6 shutdown margin at beginning of life (BOL) and end of life (EOL) conditions as given in Westinghouse Report WCAP-9954
" Core Physics Characteristics on the Zion Station Nuclear Plant, Unit 2, Cycle 6," Revision 1, dated December 1981. The inspector noted that the results of the control rod worth measurements are used in lieu of a specific physics test to verify shutdown margin.
The inspector reviewed the licensee's minimum shutdown margin calculations for both BOL and EOL conditions and concluded that the applicable Technical Specifications would be met.
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No items of noncompliance or deviations were identified.
8.
Isothermal Temperature Coefficient The inspector reviewed information relating to Cycle 6 determination of the isothermal temperature coefficient (ITC) as described in surveillance procedure T.S.S. 15.6.44, " Isothermal Moderator Temperature Coefficient Measurements", dated March 29, 1979. The Technical Specifications require, except during low power physics testing, that the moderator temperature coefficient (MTC) be negative.
In addition, the licensee's acceptance criteria requires that the isothermal temperature coefficient be within 3 pcm/*F of the predicted value. The inspector determined that these requirements were satisfied for both the all rods out (ARO) condition and when the refer-ence bank (Bank D) was inserted. The inspector noted that during the ARO ITC measurements the mixed bed demineralizer was not valved out contrary to procedure. This resulted in a slight skewing of the data.
The licensee identified this error and committed to a procedure chcnge to prevent recurrence.
No items of noncompliance or deviations were identified.
9.
Power Coefficient of Reactivity I
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The inspector reviewed information relating to the Cycle 6 determination of power coefficient of reactivity as described in surveillance procedure T.S.S. 15.6.61, "At Power Physics Measure-ments Following Refueling", dated April 1, 1981, T.S.S. 15.6.62, l
"Moderstor Temperature Coefficient", dated July 9, 1980. The predicted design values for the power coefficient were -9.9 and -8.7 pcm/% power at 72% and 98% power, respectively. The corresponding measured values were -9.1 and -8.4 pcm/% power.
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No items of noncompliance or deviations were identified.
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10.
Target Axial Flux Difference Calculations
The inspector reviewed information related to the determination of target axial flux difference as described in surveillance procedure T.S.S. 15.5.1, " Determination of AI Operating Limits", dated March 3, 1977. The inspector examined surveillance test data taken on
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November 5, 1981 and April 28, 1982 and concluded that the licensee had satisfied the Technical Specification requirements to determine the target axial flux difference at least once per equivalent full power quarter and to update target differences monthly.
i No items of noncompliance or deviations were identified.
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11.
Core Thermal Power Evaluation The inspector reviewed information related to the evaluation of core thermal power as determined by the onsite computer calorimetric and by hand calculation as described in procedure PT-0, Appendix M,
" Calorimetric", dated March 5, 1979. The inspector verified that
the onsite computer program was working properly, and that the core thermal power calculated with the above procedure was in good agree-ment with that determined by the computer. The inspector noted the procedure was being revised so that data would be taken at the computer input terminals instead of at the instruments; thus, reducing reading errors and delay times associated with data collection. The inspector also noted that the licensee would consider
incorporating a primary heat balance into the startup program.
No items of noncompliance or deviations were identified.
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Core Power Distribution Limits The inspector reviewed the surveillance procedure T.S.S. 15.6.0,
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" Flux Map Data Acquisition, Power Distribution, and Incore/Excore Axial Imbalance Checks", dated April 14, 1980 and the results of full core maps taken since the Unit 2 startup. The inspector noted that detector F had failed and that four fuel assemblies had failed l
the FAH design acceptance criteria. The licensee stated that fuel
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assembly R-8 appeared to be causing the problem and that Nuclear i
Fuel Services had been notified. Examination of all full core maps taken since startup indicated that the anomaly was burning itself out as expected. With this exception, the inspector determined that all prerequisites were met, the onsite computer was using input values from the actual plant conditions, all thermal margins satisfied Technical Specification requirements, and the calculated
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values by the computer were within the acceptable criteria established by the licensee.
No items of noncompliance or deviations were identified.
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13.
Determination of Reactivity Anomalies t
i The inspector reviewed information related to the determination of
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reactivity anomalies for Cycle 6 as described in surveillance procedure
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T.S.S. 15.6.29, " Reactivity Anomaly Check", dated August 5, 1977 and concluded that the applicable Technical Specification was met.
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inspector noted that the licensee was in the process of revising
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the procedure to include its periodic reactivity anomaly surveillance.
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No items of noncompliance or deviations were identified.
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14.
Refueling Event
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The inspector noted that on October 7, 1981 during the Unit 2 Cycle 5/6 refueling, fuel assemblies T60B and S55 were damaged
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when an incore thimble was not retracted prior to fuel movement.
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T60B was repaired and S55 was discharged, necessitating the
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J development of a new core loading pattern. The inspector noted that although the event had a significant impact on the core load,
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it was not considered a reportable occurrence by Technical Specifications.
No items of noncompliance or deviations were identified.
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15.
Review of Periodic and Special Reports i
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The inspector reviewed the Zion Unit 2 Cycle 6 Rod Swap Report
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dated January 1982 and found the test results and supporting infor-i mation discussed in the report to be consistent with design predictions
and Technical Specifications.
i No items of noncompliance or deviations were identified.
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Exit Interview I
The inspector met with licensee representatives (denoted in Paragraph 1)
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at the conclusion of the inspection on May 14, 1982. The inspector summarized the purpose, the scope of the inspection, and the findings.
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