IR 05000395/1986014

Insp Rept 50-395/86-14 on 860728-0801.No Violations or Deviations Noted.Major Areas Inspected:Bases for Thermal Power Determination & Comparison of Calculated Thermal Power W/Power Determined from Microcomputer Program TPDWR2

ML20214M231
Person / Time
Site:	Summer
Issue date:	08/20/1986
From:	Burnett P, Jape F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20214M222	List: IR 05000395/1986014 ML20214M220
References
50-395-86-14, NUDOCS 8609110020
Download: ML20214M231 (12)

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Snafru UNITED STATES

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NUCLEAR REGULATORY COMMISSION

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j 101 MARIETTA STREET. * ATLANTA, GEOHGI A 30323

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Report No.: 50-395/86-14 Licensee: South Carolina Electric and Gas Company Columbia, SC 29218 Docket No.: 50-395 License No.: NPF-12 Facility Name: Summer Inspection Conducted: July 28, 1986 - August 1, 1986 Inspector: /Jo P. T. Burnett V V Date Signed Approved by: cex4 F. Jape, Section Chief b [k~

Date Signed y/

Engineering Branch Division of Reactor Safety SUMMARY Scope: This routine, unannounced inspection addressed the bases for the licensee's thermal power determination and comparison of the licensee's calculated thermal power with those determined from the c'icrocomputer program TPDWR Results: No violations or deviations were identified.

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REPORT DETAILS

, Persons Contacted Licensee Employees

• 0. S.- Bradham, Director Nuclear Plant Operations J. L. Skolds, Deputy Director, Operations and Maintenance M. N. Browne, Group Manager, Technical and Support Services

• S. F. Hunt, Manager, Quality Control

• A. R. Koon, Manager, Technical Support

• G. G. Putt, Manager, Scheduling and Project Management

• W. R. Higgins, Associate Manager, Regulatory Compliance

• G. G. Soult, Associate Manager, Maintenance

"G. J. Taylor, Associate Manager, Computer Services

• M. A. Garrett, Quality Assurance Supervisor L. R. Cartin, Senior Engineer, Nuclear. Fuels Group

• J. Cobb, Senior Engineer, Performance and Results S. F. Fipps, Senior Engineer, Nuclear Fuels Group L. A. Wooldridge,. Senior Engineer, Computer Services

• R. M. Campbell, Engineer, ISEG W. Charleston, Engineer, ISEG A. M. Monroe, Engineer, Regulatory Compliance Other licensee employees contacted included engineers, operators, and office personne NRC Resident Inspectors

• L..Prevatte, Senior Resident Inspector

• P. C. Hopkins, Resident Inspector

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• Attended exit interview Exit Interview The inspection scope and findings were summarized on August 1,1986, with those persons indicated in paragraph 1 above. The inspector described the areas inspected and discussed in ' detail the inspection finding No dissenting comments were received from the license The licensee did not identify as proprietary any of the materials provided to or reviewed by the inspector during this inspection. Management made a commitment not to implement the SCALS program, other than QCOREl, without first notifying Region I Inspector Followup Item 395/86-14-01: Review corrective action to assure adequate 50.59 reviews - paragraph l

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2 Licensee Action on Previous Enforcement Matters This subject was not addressed'in the inspection.

, Unresolved Items No unresolved item was identified during this inspectio . Review of Licensee's Heat Balance Program (92705) The SCALS Program used at V. C. Summer Station SCALS refers to five different methods of determining reactor thermal power. These are:

(1) Secondary side heat balance based upon feed water flow (QCORE1).

(2) Secondary side heat balance based upon steam flow (QCORE2).

(3) Primary side heat balance (QCORE3).

(4) Primary side delta T (QCORE4).

(5) Turbine first stage pressure (QCORES).

In SCALS all methods were equally weighted when it was first put into use, although, the last four methods were established by normalization to the first, which is the only method using independently calibrated instruments. In addition, a lack of independence among the measure-ments, in particular 1 and 2, and 3 and 4 is obvious, but is ignored by equally weighting the calculation Chronology of SCALS Development (1) July 23,1984: " Operation at the License Limit," a consultant report (actually an internal memorandum) proposing the use of SCALS to assure that the power level over a shift averaged 100%

RTP, and to ultimately justify operation (following a change in technical specifications) at greater than 100%, by taking credit for the greater precision that SCALS would bring to power measuremen For example, if SCALS could be shown to have an uncertainty of only 1% instead of the 2% assumed in the FSAR, then operation at 101% of current rated thermal power (RTP) would be justifie (2) September 7,1984: " Computer Specifications for Operation at the Licensed Limit Program," a consultant report / internal memorandum that provided the details of computer requirements necessary for future implementation of SCAL .

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(3) -March 8,1985: "Re-evaluation of POT-20 and HST-7 Relative to RC Flow, Core -Power and P-2500 RCL Net Heat Input Constants," was performed by the consultant to create constants for use with the SCALS progra POT-20 was a startup test procedure used to collect and evaluate thermal power measurements and setpoint data during initial operation of the plant. During pre-operational testing HST-7 was a test of pressurizer spray and heater capability. The P-2500 is the Westinghouse plant computer, which was installed with a capability to perform an online heat balance based upon feedwater flo (4) March 1985: Installation of the program RT5CALS (real time SCALS)

was started on the on-site VAX compute (5) May 14, 1985: " Calorimetric Error Analysis Results for.Each of the SCALS Methods," was the consultant's report to document the details of his error analysi (6) July 22,1985: " Conversion of the SCALS to a real time system (RT5CALS)," an internal memorandum from the site computer group documenting that RT5CALS was installed and operational on the P-2500 in accordance with the consultant's specification (7) August 1985: Continuous use of SCALS for testing purposes began and continued throughout the balance of cycle (8) January 1986: With the start of fuel cycle 3, the use of SCALS for thermal power surveillance bega The original method of performing heat balance remained active on the computer and consistently showed a higher power, by about 1%, than the output from 5CAL Members of management responsible for the installation of SCALS continued to monitor its performance. They had set an acceptance criterion of 12% agreement between SCALS and QCORE (9) February 12, 1986: A lithium injection flow test was performed by a contractor (Combustion Engineering) to measure the extent of feedwater fouling. The results were not expected before March 3, 198 When received, the results indicated no fouling of the feedwater venturi (10) February 12, 1986: A meeting was held among the manager of technical support, manager of operations, and a senior nuclear

ystems engineer (NSE) to discuss the concerns he had raised about SCALS. The NSE concerns were that an adequate review of the SCALS implementation had not been performed as required by 10 CFR 50.5 FSAR 15.1.4 describes the method of thermal power determination to be a secondary side heat balance based upon feedwater flow (the QCORE1 method), and the FSAR description had not been considered

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during' the initial review of SCALS installatio The NSE challenged the conclusion that the feedwater venturis were fouled thus justifying not operating solely by QCORE1. No fouling had been observed during the last outage. QCORES, which is based upon turbine first stage pressure, was, in his judgement, a measure of secondary side efficiency rather than a reliable measure of -

reactor thermal power. The constants used in in QCORE2 - QCORE5 had not been adjusted for system changes, plugging steam generator

' tubes, and instrument recalibrations during the last outag Thus, the four secondary methods should be renormalized to QCORE (11) March 14, 1986: The Nuclear Fuel Management group issued recommendations on future use of SCALS: Incorporate a revised error analysis methodolog . Weight QCORE2 to near zero until steam flow measurement stabilizes enough to be used for calibration purpose . Weight QCORES to near zero until cyclic variation can be adequately included in the error analysi . Remove or revise original reactor power calculation from P-2500 to be consisten (This was a human factors consideration to avoid giving the operators conflicting information).

(12) March 14,1986: A PSRC meeting was held to address the the SCALS proble A revised 50.59, which considered FSAR 15.1.4, was approve A directive was issued to set the multipliers for QCORE2 and QCORE5 to zero. A member of management was tasked to establish better methods for performing 50.59 reviews.'

In a

! sense, SCALS became 3CALS.

l (13) March, 1986: B&W was contracted to perform an independent evaluation of SCAL (14) June 9,1986: The B&W report was published. It found the general approach of SCALS to be acceptable, but recommended that the four secondary methods be used only for trending performance rather than for power determination. Based upon error analysis and lack of complete independence of the five methods, it was critical of the equal weighting. In the B&W analysis, QCORE1 should be weighted 68%, and not 20%. The report 'also identified an engineering error in QCORE2, and statistical and mathematical errors in QCORE3 and QCORE For QCORES, B&W was unable to verify the correlation used between turbine pressure and thermal power, and calculated a new correlatio . _ -_

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(15) June 18, 1986: An ISEG engineer identified errors in the constants used in QCORE3, leading to underestimating powe In response to the recommendation in off normal report 86-116, the licensee weighted QCORE? and QCORE4 to zero. Since that time thermal power determination his Lien based solely on feedwater flow and enthalpy change (QCORE1), Conclusions The failure to perform an adequate safety review of the implementation of SCALS, as required by 10 CFR 50.59 has been classified as a licensee-identified violation (LIV 395/86-14-02: Failure to perform an adequate 50.59 review). Corrective action will be tracked under inspector follow item 395/86-14-01: Review corrective action to assure adequate 50.59 review No other violations or deviations were identifie . Comparison of Power Calculations (61706)

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TPDWR2 is a microcomputer program developed by the NRC Independent Measure-ments Program for independent evaluation of thermal power using licensee-supplied input data. It is described in NUREG-116 Using plant data, independent calculations of thermal power were performed using TPDWR2 on the IBM-PC in the resident inspectors' office. TPDWR2 consistently indicated about 8 Mwth less than QCORE1. The agreement is good, and no cor.clusive reason for the difference has been established. Two possible contributors to the difference is that feedwater enthalpy is calculated at steam pressure by TPDWR2 and at feedwater pressure by QCOREl, and that the inspector chose to use moisture carryover fractions determined by the lithium test in February 1986, while the licensee method uses the fractions determined during initial startup test It does not appear that the licensee at any time exceeded 102% power as calculated by QCORE1. When SCALS was in use, the highest power indicated by QCOREI was 2807.9 MWth (101.12% RTP) on February 26,1986 according to a

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review of operating records conducted by the license Results of the TPDWR2 calculations are attached to this report. Attachment 1 consists of the standard plant specific parameters, which remained constant throughout the series of calculations, and a typical set of two-observation input data. The parameters for the reflection insulation were adjusted to

give the same insulation heat loss as the licensee measured during startup operation Attachment 2 shows the calculational results for the input data from

^ attachment It should be noted that not all the points monitored for the TPD R2 calculation were the same as those monitored by QCOREl, but the points selected were as valid and qualified as the other .. _ - - _ . -- _

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t Attachment 3 is a direct, one-set-of-observations comparison of the two i calculations. Data recorded by 5CALS for QCORE1 were input to TPDWR Note that QCORE1 pressure data are in psig and must be converted to psia for input to TPDWR No violations or deviations were identifie ,

Attachments: Plant Parameters and Typical Input Data for TPDWR2 TPDWR2 - Calculated Results Direct Comparison with Licensee Calculation

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. ATTACHMENT 1

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EI N CIA Plant Parameters and Typical Input Data for TPDWR2 V. C. RNO 1 31 July 1986 PUWT PNWETERS:

REACTORU10UWTSYSTEM -

REFLECTM MilLATION Pump Pouer (101 each) Inside Salace Ar u Isq ft) 94,050 -

PumpEfficiency(1) 9 HeatLossCoefficient(94/hrsqft) 55.00 Preswirer Inside Dieseter (inches) 9 EFLECTIVE IIELLATION

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STEAM IBERATORS Inside Seface Area (sq ft) 0 Dose Inside Diameter (inches) 168.50 Thickness (inches) Riser Outside Diameter (inches) 20.00 Thermal Conductivity (BTUs/hr it F) 0.000 e

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ibs b of Risers 12 . _ . . ,,

Ibistre Carry-over II) in A 0.032 LICENSED TERMAL P06 (MWt) 2775 Moisture Carry-over (1) in B 0.029 MoistureCarry-over(1)inC 0.960 DATA: SET 1 SET 2 SET 1 SET 2 TIE 0940 0955 TIE 09 4 0955 STEAM GD G A R A STEAMGEEATORI SteaePreswe(psia) 94 .9 Steaa Preswe (psia) 94 .4 FeedsterFlou(E6lb/hr) 4.065 4.079, FeeduterFlou(E4lb/hr) 3.959 3.950 Feeduter Teeperature (F) 43 .9 Feeduter Temperature (F) 43 .4 SurfaceBloudoun(gpa) .0 SefaceBloudoun(pe) .0 BottonBloudoun(gpe) 3 .6 BottosBloudoun(gpe) 4 .3 hierLevel(inches) 13 .3 hter Level (inches) 13 .8 STIN1IBOATORC SteasPreswe(psia) 94 .0 Feedutor Flou (E6 lb/hr) 4.149 4.129 Feedster Temperature (F) 43 .4 Surf ace Bloudoun (gpe) .0 Botton Bloudoun (gpe) 3 .4 hterLevel(inches) 13 .9 LITDOW LIE OWSING LIE Flou (pa) 10 .6 Flou (pe) 8 .8 Temperature (F) 55 .7 Temperature (F) 46 .3

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PRESSLRIZER RE/CTOR Preswe(psia) 2250.0 225 Tave(F) 58".0 58 '

hte Level (inches) 11 .5 icold(F) 55 .1

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ATTACHMENT 2

. TPDWR2-Calculat:d Results Page 1 of 2 HEAT BALANCE V. C. SUMMER 1 31 July 1996

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DATA SET 1 0F 2 ENTHALPY FLOW POWER POWER 0940 hours0.0109 days <br />0.261 hours <br />0.00155 weeks <br />3.5767e-4 months <br /> (BTUs/lb) (E6 lb/hr) (E9 BTus/hr) (MWt)

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STEAM SENERATOR A Steam 119 .052 4.841 . . .

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Feedwater 41 .065 -1.681 -- -

Surface Blowdown 53 .00000 0.00000 Botton Slowdown 47 .01232 0.00581

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Power Dissipated 3.1650 927.2 t

STEAM BENERATOR B Steam 119 .940 4.707 Feedwater 40 .959 -1.623 Surface Blowdown 53 .00000 0.00000 Bottom Blowdown 46 .01694 0.00796

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Power Dissipated - 3.0914 90 STEAM 6ENERATOR C Steam 118 .135 4.917 Feedwater 40 .149 -1.697 Surface Blowdown 53 .00000 0.00000 Bottom Blowdown 46 .01226 0.00576

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Power Dissipated 3.2265 94 OTHER COMPONENTS Letdown Line 55 .03813 0.02109 Charging Line 44 .03492 -0.01556 Pressurl er 63 .00009 0.00005 Pumps -0.05233 Insulation Losses 0.00517

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Power Dissipated -0.04158 -1 ......

REACTOR POWER 276 .

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HEAT SALANCE V. C. SUMMER 1 31 July 1986

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DATA SET 2 0F 2 ENTHALPY FLOW POWER POWER 0955 hours0.0111 days <br />0.265 hours <br />0.00158 weeks <br />3.633775e-4 months <br /> (BTus/lb) (E6 lb/hr) (E9 ITUs/hr) (MWt)

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STEAM SENERATOR A Steam 119 .067 4.959 '

Feedwater 41 .079 -1.687 ..-__

Surface Blowdown 53 .00000 0.00000 botton Blowdown 47 .01224 0.00577

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Power Dissipated 3.1771 93 STEAM BENERATOR 9 Steam 119 .931 4.696 Feedwater 40 .950 -1.619 Surface blowdown 53 .00000 0.00000 Botton Slowdown 46 .01654 0.00777

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Power Dissipated . 3.0048 90 STEAM GENERATOR C Steas 118 .115 4.893 Feedwater 40 .129 -1.688 Surface Blowdown 53 .00000 0.00000 Bottoe Blowdown 46 .01218 0.00572

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Power Dissipated 3.2105 94 '

OTHER COMPONENTS Letdown Line 55 .03794 0.02098 Charging Line 44 .03506 -0.01568 Pressurizer 63 .00009 0.00005 Pumps -0.05233 Insulation Losses 0.00517

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Power Dissipated -0.04100 -1 ......

REACTOR POWER 276 .

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ATTACHMENT 3 l

• Direct Comparison with Licenste Calculation: Page 1 of 2 TPDWR2 Result HEAT BALANCE V. C. SUMMER 1 31 3ULY 1986 DATA SET 1 OF 1 ENTHALPY FLOW POWER POWER 1005 hours0.0116 days <br />0.279 hours <br />0.00166 weeks <br />3.824025e-4 months <br /> (BTUs/lb) (E6 lb/hr) (E9 BTUs/hr) (MWt)

STEAM GENERATOR A Steam 119 .053 4.842 Feedwater 41 .065 -1.681 Surface Blowdown 53 .00000 0.06000 Bottom B1owdown 47 O.01223 0.00577

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Power Dissipated 3.1661 92 STEAM GENERATOR B

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Steam 119 .944 4.712 i Feedwater 41 .960 -1.624 Surface Blowdown 53 O.00000 0.00000 j Bottom Blowdown 46 .01640 0.00770 Power Dissipated 3.0956 90 STEAN GENERATOR C Steam 118 .141 4.924 Feedwater 40 .153 -1.698 Surface Blowdown 53 O.00000 O.00000 Bottom Blowdown 46 .012.18 0.00576 ,

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Power Dassipated 3.2320 94 OTHER COMPONENTS Letdown Line 55 .03779 0.02090 Charging Line 44 .03506 -0.01568 Pumps -0.05233 Ins.ulation Losses 0.00517

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[ Power Dissipated -0.04193 -1 ______

REACTOR FOWER 2768.2 l

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TAsLE SCOR1 SECONDARY SIDE CALORIRETOIC RESULTS ATTACHMENT 3 *

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BASED UFON MECSURED FO FLOW Page 2 of 2 Licensee Result

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VC SunnER NUCLEAR UNIT

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DATE: 7/31/94 TINE: 10:05 (

. PARAMETER LOOP-A LOOP-8 LOOP-C

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FW FLOW,LS/H 404539 .0 415312 (

. ... STEAA FLOW, LS/M 405399 .0 414170 STR SEN SO FLOW, LS/H 1140 .2 1141 (

STA SEN PRESS, PSIA 94 .5 94 (

. FINAL FW TERP, F 43 .3 43 EMTHALPT OF STM, BTU /LB 119 .4 119 (

ENTHALPY OF FW, BTU /LB 41 .9 41 *

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.. DM (HSTA - NFW), STU/L5 78 .7 78 NORAALIZATION CONSTANT 1.000409 1.000409 1.000409 , (

STA SEN POWER, MWT 93 .0 95 (

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TOTAL NSS POWER, AWT 278 (

. . RCP HEAT INPUT, NWT 14.97

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P2R HEATER HEAT INPUT, NWT 0.15 (

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' NSS INSULATION HEAT LOSS, RWT 1.52 (

. RC LETDOWN HEAT LOSS, MWT 2.72 CORE POWER, nWT 277 <

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CORE POWER, IFP 100.'04 (

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