IR 05000483/1988002

Safety Insp Rept 50-483/88-02 on 880105-14.No Violations or Deviations Noted.Major Areas Inspected:Licensee Actions on Previous Insp Findings,Control Rod Testing,Core Power Distribution Limits & Calibr of Nuclear Instrumentation Sys

ML20196C411
Person / Time
Site:	Callaway
Issue date:	02/04/1988
From:	Azab B, Phillips M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20196C399	List: IR 05000483/1988002 ML20196C396
References
50-483-88-02, 50-483-88-2, NUDOCS 8802160094
Download: ML20196C411 (7)

Text

_

,

. .

e

.

U.S. NUCLEAR REGULATORY COMMISSION

REGION III

Report No. 50-483/88002(DRS)

Docket No. 50-483 -License No. NPF-30 Licensee: The Union Electric Company P. O. Box 149 St. Louis, M0 63166 Facility Name: Callaway, Unit 1 Inspection At: Callaway Site, Callaway County, Missouri Inspection Conducted: January 5 through 14, 1988 Inspector: B. A. Azab be h ed/4!88 _,

Approved By:

Monte P.'Phillips, Chief Da te '

fh Operational Programs Section Inspection Summary:

Inspection on January 5 through 14, 1988 (Report No. 50/483/88002(DRS))

Areas Inspected: Routine, unannounced safety inspection of licensee action on previous inspection findings (92701), control rod testing (72700), core power distribution limits (61702), calibration of nuclear instrumentation systems (61705), core thermal power evaluation (61706), isothermal and moderator temperature coefficient determinations (61708), Shutdown margin /

boron endpoint calculations (61707), and control rod worth _ measurements i

(61710).

Results: No violations or deviations were identifie !

i G 4

- _ _ _ _ - _ _ _

. .

.

.

DETAILS 1. Persons Contacted Union Electric

• L. Randolph, General Manager, Nuclear Operations

• K. Bryant, Reactor Engineer

• J. C. Gearhart, Superintendent, Quality Assurance Operations Support

~

J..Little, Quality Assurance Engineer

• R. J. McCann, Quality. Assurance Engineer

• T. M. McFarland, Superintendent, Systems Engineering

• T. Moser, Supervisor, Reactor Engineering

• C. Naslund, Manager, Operations Support

• S. Petzel, Quality Assurance Engineer U.S. Nuclear Regulatory Commission B. Little, Senior Resident Inspector

• M. Brown, Resident Inspector The inspector also interviewed other licensee personnel during the course of the inspection, including members of the technical and operations staf * Denotes persons attending the exit meeting on January 14, 1988. Licensee Action on Previous Inspection Findings (92701) (Closed) Unresolved Item (483/86018-02) and Licensee Event Repor l (483/86025-LL): )

During a NRC review of an incident where the plant exceeded licensed reactor power, which resulted in the issuance of a Notice of Violation '

(483/86018-01(DRS)); the licensee volunteered the information that a similar incident occurred on December 3, 1984. The item was left unresolved pending the licensee's determination.that 100% reactor thermal power was, in fact, exceeded due to conservatisms in the calculations and reassessment of the event for reportability. The licensee reassessed the December 1984 incident and concluded that {

reactor power was approximately 101% for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. Licensee Event Report (LER) No. 86025 was submitted on August 6, 1986, which reported both event Adequate corrective actions had been implemented in response to the previous violation to prevent recurrence of operation in excess of 100% core thermal power; therefore, the above unresolved item and LER are considered close The inspector has no further concerns in this are _ _ _ - _ _ _ _ _

_ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _

_

. .

.

e (Closed) Open Item (483/86020-01(ORP)):

On November 18, 1986, the licensee determined the existence of a thermal hydraulic anomaly, which-was characterized by small, simultaneous changes in several plant parameters (reactor power, core exit temperature, core flow, and delta pressure) which occurred randomly every two to five minutes. The inspector reviewed a report,

"RCS Flow Anomaly Investigation- Report," produced by Westinghause, dated December 10, 1987. The investigation by Westinghouse concluded that the anomaly was caused by rotational flow cells (vortices) in the reactor lower plenum which cause local disturbances in core inlet flow and lead to the observed' data fluctuations. The report also included the discussion of a safety evaluation which concluded, in part, the following:

(1) The flow anocsiy has no impact on large and small break LOCA analysi (2) Adequate. departure from nucleate boiling (DNB) margin exists to accommodate for the DNB penalty resulting from the anomal (3) The structural integrity of the reactor internals is not, expected to be affected since it appears sufficient fatigue margin exists and the cross flow effects on the fuel rods are within acceptable limit Callaway plant personnel were continuing to monitor the anomal Strip chart recorders were set up at the beginning of Cycle 3 which demonstrated that the anomaly still existed with the same approximate frequency and change in plant parameters that were identified in Cycles 1 and 2. The anomaly was monitored on a monthly basis and trended so that any change in the anomalous behavior could be detected. No change in the anomaly has been

-

found to dat This item is considered closed based on the results of the Westinghouse Safety Evaluation and continued monitoring by the license ,

No violations or deviations were identifie . Control Rod Testing (72700)

The inspector reviewed the completed procedure ESP-ZZ-00016, "Rod Drop Time Measurement," Revision 2, performed November 3-5, 1987, for compliance with Technical Specification 3/4.1.3.4., which required a rod drop time from the fully withdrawn position to the dashpot entry of less than or equal to 2.7 second The surveillance was performed properly, and the results complied with the Technical Specification No violations or deviations were identifie _

. . .

.

. Core Pcwor Distribution Limits (61702)

The inspector reviewed a number of procedures in the area of core power distribution limits for technical adequacy and compliance'with Technical Specification limits and surveillance-frequency requirements. The inspector veriffed that the licensee complied with Technical' Specification limits on quadrant power tilt ratio, hot channel factors, axial flux difference, and departure from nucleate boiling parameters by reviewing the following completed surveillances:

• OSP-SE-00003, "Quadrant Power Tilt Ratio Calculation," Revision'4, performed December 2,1987 and January 5,198 * OSP-ZZ-00001, "Control Room Shift and Daily Log-Readings and. Channel Checks, Modes 1 through 4," Revision 10, dated December 18-25, 198 * ESP-ZZ-00012, "Target Flux Difference Update and Measurement," ;

Revision 6, performed November 30, 198 * ESP-ZZ-00017, "Nuclear Enthalpy Rise Hot Channel Factor," Revision 5, performed December 30, 198 * ESP-ZZ-00014, "Heat Flux Hot Channel Factor," Revic. ion 5, dated November 18 and 27, 198 * Flux Map No.87-033, dated November 27, 1987, and No.87-034, dated December 22, 198 No violations or deviations were identifie . Calibration of Nuclear Instrumentation Svstems (61705) <

'

The inspector reviewed procedure ESP-ZZ-00006, "Incore/Excore Calibration,"

Revision 9, performed November 20, 1987, and procedure ETP-SE-ST001,

"Nuclear Instrumentation Startup Testing," Revision 4, completed December 2, 1987, for procedure adequacy and compliance with acceptance criteria and Technical Specifications. The procedures were found to be l

'

acceptable and all acceptance criteria and Technical Specification requirements were me . Core Thermal Power Evaluation (61706)

The inspector verified the adequacy of procedure OSP-SE-00004, "NIS ;

Power Range Heat Balance," Revisian 6, by independently perfonning a I heat balance calculation and obtv ning the same result as the license The inspector reviewed a week's sample of completed heat balances and verified compliance with Technical Specification frequency requirements !

and proper adjustment of the power range nuclear instrumentation when j necessar The inspector noted during the review that the heat balance '

result for December 30, 1987, was 100.04% core thermal pode However,

I I

4 I H

,

-

,

C i /.

. .

.

h this was an. instantaneous power; further inspection exhibited that the average core thernsi power for that hour was less than 100% as well as

'

the average power.for an eight hour shift before and after the time of the 100.04% power readin No violations or deviations were identifie . Isothermal and Moderator Temperature Coefficient Determinations (61708)

The inspector reviewed procedures and.results related to the Cycle 3 zero power moderator temperature coefficient (MTC). measurement and verified that the prerequisites, acceptance criteria, and Technical Specifications were met. The inspector noted that the MTC was measured to be a positive, 0.372 pcm/ F. Callaway Technical Specification 3.1.1.3 states, in part,-

that the MTC shall be less positive than 0 ^k/k/ F for all the rods withdrawn, beginning of life, hot zero thermal power condition, or control rod withdrawal limits must be established and maintained to restore the MTC to less positive than 0 'k/k/ F, and a Special Report must be submitted to the NRC. The inspector reviewed the calculations determining rod withdrawal limits for technical adequacy and verified the limits were being maintained. The inspector,also reviewed the Special Report submitted to the NRC which discussed the positive MTC, the withdrawal limits, and the core burnup needed to restore a negative MTC for the "all rods withdrawn" condition. The following documents were utilized during the review:

• ESP-ZZ-00009, "Moderator Temperature Coefficient Measurement at Zero Power," Revision 3, dated November 9, 198 * ETP-ZZ-00014, "Negative Moderator Temperature Coefficient Maintenance Calculation," Revision 3, dated November 12, 198 * Special Report 87-13, "Callaway Plant Positive Moderator Temperature Coefficient," dated November 16, 198 * Cycle 3, Nuclear Design Repor No violatiens or deviations were identifie . Shutdown Margin / Boron Endpoint Calculations (61707)

The inspector reviewed procedure OSP-SF-00001, "Shutdown Margin Calce:ation," Revision 7, performed November 14, 1987, and verified compliance with Technical Specification 3.1.1.1. which requires a shutdown margin greater than or equal to 1.3% 'k/ l The inspector also reviewed procedure ETP-ZZ-ST004, "Boron Endpoint ,

Measurement," Revision 2, performed November 6 and 7,1987, for the ;

all rods out, control bank 0 inserted and both control banks D and C inserted conditions. The inspector identified one concern during the i revie The design review criteria for the configurations other than j i

. - . -

.

.. .

.-. ,,

.

.

the all rods out. condition, is for the critical boron concentration to ' >

be within 1.15% or i 10 ppm (whichever isf greater)'of its design valu On Data Sheet 8.3., Step 4, the formula used to calculate the. percentage difference of- the design value was written incorrectly so that it'

calculated the percentage difference of the measured ~value. 'This resulted in a slight error in the nonconservative direction; however, the correct values were well within the i 15% acceptance criterio In response to the inspector's-concern, the licensae wrote a test change (Test-Change No.'88-0011) to the procedure which. corrected the formula, recalculated the percent differences, and documented th correct result The inspector has no.further concerns in this are '

No violations or deviations were identifie . Control Rod Worth Measurements (61710)

The inspector reviewed licensee procedures and results related to the calculation of control rod worths an'd verified that acceptance criteria '

were me The following documents were used during.the review:

• ETP-ZZ-ST005, "Bank Reactivity Worth Measurement," Revision 2, performed for control banks A threugh D on November 7 and 8, 198 * ETP-ZZ-ST001, "Low Power Physics Testing Data Acquisition,"

Revision 3, performed November 6 through 9, 198 * ETP-ZZ-ST003, "Determination of Low Power Physics Testing Range,"

Revision 1, performed November 6, 198 ,

• Cycle 3, Nuclear Design Repor The inspector noted several concerns with respect to ETP-ZZ-ST00 The first concern dealt with the same formula previously identified as incorrect on the boron endpoint procedure. The formula was also erroneous on the rod worth procedure; however, the licensee identified the error and corrected the formula during the performance of the tes Although the correct results were documented within the body of the procedure, the results from the incorrect formula were listed in the Test Report which is used to summarize procedure results. The licensee corrected the erroneous numbers in the Test Report on January 13, 198 One of the prerequisites for procedure ETP-ZZ-ST005 is that the flux level be within the range established for low power physics testin The inspector noted that the power level documented on Data Sheet .

of the procedure measuring control bank A worth was below the allowable power range for testing. The licensee verified through other documents that the plant was, in fact, at the correct power level during the test and the number was recorded incorrectly by writing a wrong exponen The number was corrected on January 13, 1988, and an explanation of the error and source of the actual power level were entered in the Special Test Lo .

,. - .- -. .

.- . . ..

. . . . .. m

,.- /- ,

Another prerequis'te for procedure ETP-ZZ-ST005 is'that the boron

~

'

concentration of the pressurizer and reactor coolant system be within 20 ppm. This prerequisite was not_ met for-the two procedures that measured control banks A and 8. The licensee indicated a note in the Special Test Log-that stated the prerequisites. were verified and ccntrol banks C through A~would be diluted.in continuously. Although the continuous dilution of the control banks had no adverse affect on the test results, the inspector was concerned that.the procedure was not-

.

followed properly because the control bank worth procedures were written as separate procedures with separate prerequisites which were1 required to be met. The licensee responded to the inspector concern by. writing Test Change No. 88-0012 which clarifies that.the prerequisite must only be met before the first bank measurement if more than one bank is continuously measured. The inspector has no further concerns in this arc No violations or deviations were identifie . Quality Assurance Effectiveness The inspector interviewed Quality' Assurance.(QA) personnel who performed an audit of the Cycle 3 physics testing program and determined theirl review to be adequate. The QA review consisted of witnessing portions .

of the testing and performing a results review of the completed test packages. QA concluded that the testing was performed correctly, and no significant deficiencies were identified in the test package However, the QA group did not find the same concerns that the inspector identifie This was due to the following:~ QA reviewed a different sample of tests than the inspector, and QA did not review the procedures for adequacy. Their review was of the completnd tests for compliance and proper performance. The licensee relies on a two year procedure review to verify procedure adequac . Exit Meeting The inspector met with the licensee representatives (denoted in Paragraph 1) on January 14, 198 The inspector summarized the scope and findings of the inspectio The inspector also discussed the-likely informations content of the inspection report with regard to documents or processes reviewed by the inspector during the inspectio The licensee acknowledged statements made by the inspector, and stated that the Westinghouse "RCS Flow Anomaly Investigation Report" referenced within this report was proprietary, but references to the document would not be considered proprietary.

.

-- , . _ -