IR 05000395/1986014
| 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: |
| References | |
| 50-395-86-14, NUDOCS 8609110020 | |
| Download: ML20214M231 (12) | |
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e Snafru UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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REGION 11 g*
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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 b
[k F. Jape, Section Chief y/
Date Signed
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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 TPDWR2.
Results: No violations or deviations were identified.
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l 8609110020 860826
{DR ADOCK 03000395 PDR
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REPORT DETAILS
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1.
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 personnel.
NRC Resident Inspectors
- L..Prevatte, Senior Resident Inspector
- P. C. Hopkins, Resident Inspector
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- Attended exit interview 2.
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 findings.
No dissenting comments were received from the licensee.
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 II.
Inspector Followup Item 395/86-14-01:
Review corrective action to assure adequate 50.59 reviews - paragraph l
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3.
Licensee Action on Previous Enforcement Matters This subject was not addressed'in the inspection.
4.
Unresolved Items
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No unresolved item was identified during this inspection.
5.
Review of Licensee's Heat Balance Program (92705)
a.
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 calculations.
b.
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 measurement.
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 justified.
(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 program.
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 flow.
(4) March 1985: Installation of the program RT5CALS (real time SCALS)
was started on the on-site VAX computer.
(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 analysis.
(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 specifications.
(7) August 1985: Continuous use of SCALS for testing purposes began and continued throughout the balance of cycle 2.
(8) January 1986: With the start of fuel cycle 3, the use of SCALS for thermal power surveillance began.
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 5CALS.
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 QCOREl.
(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, 1986.
When received, the results indicated no fouling of the feedwater venturis.
(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 50.59.
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 installation.
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 outage.
Thus, the four secondary methods should be renormalized to QCOREl.
(11) March 14, 1986: The Nuclear Fuel Management group issued recommendations on future use of SCALS:
1.
Incorporate a revised error analysis methodology..
2.
Weight QCORE2 to near zero until steam flow measurement stabilizes enough to be used for calibration purposes.
3.
Weight QCORES to near zero until cyclic variation can be adequately included in the error analysis.
4.
Remove or revise original reactor power calculation from P-2500 to be consistent.
(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 problem.
A revised 50.59, which considered FSAR 15.1.4, was approved.
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
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sense, SCALS became 3CALS.
l (13) March, 1986: B&W was contracted to perform an independent evaluation of SCALS.
(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 QCORE4.
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 power.
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),
c.
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 reviews.
No other violations or deviations were identified.
6.
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-1167.
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 tests.
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 review of operating records conducted by the licensee.
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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 operations.
Attachment 2 shows the calculational results for the input data from
^ attachment 7.
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 others.
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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 TPDWR2.
Note that QCORE1 pressure data are in psig and must be converted to psia for input to TPDWR2.
No violations or deviations were identified.
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Attachments:
1.
Plant Parameters and Typical Input Data for TPDWR2 2.
TPDWR2 - Calculated Results 3.
Direct Comparison with Licensee Calculation
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ATTACHMENT 1
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Plant Parameters and Typical
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Input Data for TPDWR2 V. C. RNO 1 31 July 1986 PUWT PNWETERS:
REACTORU10UWTSYSTEM
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REFLECTM MilLATION Pump Pouer (101 each)
5.5 Inside Salace Ar u Isq ft)
94,050
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PumpEfficiency(1)
93.0 HeatLossCoefficient(94/hrsqft)
55.00 Preswirer Inside Dieseter (inches)
94.0 100EFLECTIVE IIELLATION STEAM IBERATORS Inside Seface Area (sq ft)
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Dose Inside Diameter (inches)
168.50 Thickness (inches)
0.0 Riser Outside Diameter (inches)
20.00 Thermal Conductivity (BTUs/hr it F)
0.000 e
ibs b of Risers
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Ibistre Carry-over II) in A 0.032 LICENSED TERMAL P06 (MWt)
2775
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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)
943.6 943.9 Steaa Preswe (psia)
947.4 946.4 FeedsterFlou(E6lb/hr)
4.065 4.079, FeeduterFlou(E4lb/hr)
3.959 3.950 Feeduter Teeperature (F)
434.9 434.9 Feeduter Temperature (F)
431.4 431.4 SurfaceBloudoun(gpa)
0.0 0.0 SefaceBloudoun(pe)
0.0 0.0 BottonBloudoun(gpe)
30.8 30.6 BottosBloudoun(gpe)
42.3 41.3 hierLevel(inches)
136.3 136.3 hter Level (inches)
138.6 139.8 STIN1IBOATORC SteasPreswe(psia)
947.7 948.0 Feedutor Flou (E6 lb/hr)
4.149 4.129 Feedster Temperature (F)
430.4 430.4 Surf ace Bloudoun (gpe)
0.0 0.0 Botton Bloudoun (gpe)
30.6 30.4 hterLevel(inches)
137.9 138.9 LITDOW LIE OWSING LIE Flou (pa)
102.1 101.6 Flou (pe)
84.2 84.8 Temperature (F)
554.7 554.7 Temperature (F)
464.1 464.3
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PRESSLRIZER RE/CTOR Preswe(psia)
2250.0 2250.6 Tave(F)
58".0 585.1
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hte Level (inches)
112.3 112.5 icold(F)
555.1 555.1
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ATTACHMENT 2
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TPDWR2-Calculat:d Results
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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 1194.7 4.052 4.841
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Feedwater 413.7-4.065-1.681
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Surface Blowdown 533.7 0.00000 0.00000 Botton Slowdown 471.6 0.01232 0.00581
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Power Dissipated 3.1650 927.2 t
STEAM BENERATOR B Steam 1194.6 3.940 4.707 Feedwater 409.9-3.959-1.623 Surface Blowdown 534.3 0.00000 0.00000 Bottom Blowdown 469.9 0.01694 0.00796
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Power Dissipated 3.0914 905.4
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STEAM 6ENERATOR C Steam 1189.1 4.135 4.917 Feedwater 408.9-4.149-1.697 Surface Blowdown 534.4 0.00000 0.00000 Bottom Blowdown 469.4 0.01226 0.00576
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Power Dissipated 3.2265 945.0 OTHER COMPONENTS Letdown Line 553.0 0.03813 0.02109 Charging Line 446.9-0.03492-0.01556 Pressurl er 635.2 0.00009 0.00005 Pumps-0.05233 Insulation Losses 0.00517
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Power Dissipated-0.04158-12.2
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REACTOR POWER 2765.4
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ATTACHMENT 2
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Pag 2 of 2
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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 1194.7 4.067 4.959
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Feedwater 413.7-4.079-1.687
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Surface Blowdown 533.8 0.00000 0.00000 botton Blowdown 471.7 0.01224 0.00577
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Power Dissipated 3.1771 930.5 STEAM BENERATOR 9 Steam 1194.7 3.931 4.696 Feedwater 409.9-3.950-1.619 Surface blowdown 534.2 0.00000 0.00000 Botton Slowdown 469.9 0.01654 0.00777
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Power Dissipated 3.0048 903.5
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STEAM GENERATOR C Steas 1189.1 4.115 4.893 Feedwater 408.9-4.129-1.688 Surface Blowdown 534.4 0.00000 0.00000 Bottoe Blowdown 469.4 0.01218 0.00572
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Power Dissipated 3.2105 940.3
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OTHER COMPONENTS Letdown Line 553.0 0.03794 0.02098 Charging Line 447.2-0.03506-0.01568 Pressurizer 635.4 0.00009 0.00005 Pumps-0.05233 Insulation Losses 0.00517
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Power Dissipated-0.04100-12.2
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REACTOR POWER 2762.0
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ATTACHMENT 3
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Direct Comparison with Licenste l
Calculation: Page 1 of 2 TPDWR2 Result HEAT BALANCE V.
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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 1194.7 4.053 4.842 Feedwater 413.6-4.065-1.681 Surface Blowdown 533.9 0.00000 0.06000 Bottom B1owdown 471.7 O.01223 0.00577
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Power Dissipated 3.1661 927.3 STEAM GENERATOR B
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Steam 1194.8 3.944 4.712 i
Feedwater 410.1-3.960-1.624 Surface Blowdown 533.6 O.00000 0.00000 j
Bottom Blowdown 469.7 0.01640 0.00770 Power Dissipated 3.0956 906.6 STEAN GENERATOR C Steam 1189.2 4.141 4.924 Feedwater 408.8-4.153-1.698 Surface Blowdown 534.O O.00000 O.00000 Bottom Blowdown 469.2 0.012.18 0.00576
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Power Dassipated 3.2320 946.6 OTHER COMPONENTS Letdown Line 553.0 0.03779 0.02090 Charging Line 447.2-0.03506-0.01568 Pumps-0.05233 Ins.ulation Losses 0.00517
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Power Dissipated-0.04193-12.3
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REACTOR FOWER 2768.2 l
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TAsLE 2.
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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CYCLE 3 OPERATION (
DATE:
7/31/94 TINE: 10:05 (
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PARAMETER LOOP-A LOOP-8 LOOP-C (
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FW FLOW,LS/H 4045398.5 3960441.0 4153127.5 (
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STEAA FLOW, LS/M 4053994.0 3745183.0 4141708.5 STR SEN SO FLOW, LS/H 11404.8 15258.2 11419.4 (
STA SEN PRESS, PSIA 947.4 945.5 947.5 (
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FINAL FW TERP, F 432.4 432.3 432.2 EMTHALPT OF STM, BTU /LB 1193.5 1193.4 1193.5 (
ENTHALPY OF FW, BTU /LB 411.1 410.9 410.9
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DM (HSTA - NFW), STU/L5 782.4 782.7 782.4
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NORAALIZATION CONSTANT 1.000409 1.000409 1.000409 (
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STA SEN POWER, MWT 930.5 905.0 950.8 (
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TOTAL NSS POWER, AWT 2787.1 (
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RCP HEAT INPUT, NWT 14.97 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 2776.2
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CORE POWER, IFP 100.'04 (
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