ML13333A503
| ML13333A503 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/13/1980 |
| From: | Baskin K Southern California Edison Co |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| TAC-44128 IEB-79-27, NUDOCS 8002260669 | |
| Download: ML13333A503 (12) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN February 13, 1980 TELEPHONE MANAGER, NUCLEAR ENGINEERING (213) 572-1401 AND LICENSING Director, Office of Nuclear Reactor Regulation Attention:
Mr. D. L. Ziemann, Chief Operating Reactors Branch #2 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen:
Subject:
Docket No. 50-206 San Onofre Nuclear Generating Station Unit 1 By letter dated December 27, 1979, from D. F. Ross to C. Reed, the NRC requested that the Westinghouse Owners Group Utilities (1) provide documentation within 21 days showing the errors (and their source) used to develop their subcooling criterion, (2) document and justify any-proposed revisions to Station procedures within 21 days if the calculated subcooling criterion does not permit timely termination of HPI for non-LOCA events, (3) acknowledge a commitment within 21 days to install instrumentation and readout devices which will provide 20oF of actual subcooling based on the criterion in the Station procedures, and (4) in conjunction with I&E Bulletin No. 79-27, confirm that sufficient instrumentation is available on redundant emergency power supplies to permit the operator to perform the actions defined in the Station procedures.
By letter dated January 23, 1980, from J. G. Haynes to D. L. Ziemann, we indicated that the information requested in Items 1, 2, and 3 would be provided by February 15, 1980, and that the information requested in Item 4 would be provided as part of our response to I&E Bulletin No. 79-27 by February 28, 1980.
The purpose of this letter is to provide our responses to Items 1, 2, and 3 as discussed below:
(1)
The Enclosure to this letter contains documentation-of the errors (and their source) used to develop our subcooling criterion. The maximum subcooling errors using the Tsat meter and the backup method (using Steam Tables) were calculated to be +/-17.5 OF and +/-18.40F, respectively.
Based on these calculations and the NRC requirement to maintain at least 20oF actual subcooling, the minimum subcooling criteria for San Onofre &L Unit 1 will be revised to 400F. This value supersedes the minimum subcooling criteria of 5 00F established by I&E Bulletin No.79-06A.
O 8002260 oI
Mr. D.
February 13, 1980 (2)
Currently, the non-LOCA transients and EOI's are being reviewed for the purpose of incorporating a subcooling criterion in the safety injection termination critera.
These activities will be completed and transmitted to the NRC by the Owner's Group Chairman.
(3)
Instrumentation and readout devices are currently installed which pro vide 20oF of actual subcooling based on the 40OF minimum subcooling criteria for safety injection termination following small break loss of coolant accidents.
If you have any questions concerning the above information, please contact me.
Very truly yours, Enclosure
Enclosure to February 13, 1980 Letter From:
K. P. Baskin To:
D. L. Ziemann Justification of RCS Subcooling Setpoint
SHEET 1
OF 9
SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET Justification of RCS Subcwling Setpoint SIGN 631
SUBJECT:
_CALCULATIONNO.
DC PMADEBY
.HPensy2/6/
80vW.G.
Flour oy2/7/80 j.,_N__60__2_._.________
AE2/
/8 CHK. BY _____
DAT 80 Table of Contents Section Title Page TSAT Meter A.
Errors in Hot Leg Temperature 2
B.
Equivalent Saturation 3
Temperature Error from Errors in Reactor Coolant System Pressure C.
Errors in Recorded Subcooling 5
Temperature II.
Backup Method using Steam Tables A.
Errors in Core Temperature 6
B.
Errors in Reactor Coolant System Pressure 7
C.
Errors in Determination of Subcooling 8
DWG. NO.
S.E OD397-B NEW 8/7
SHEET 2
OF 9
SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET SJBJECT: Justification of RCS Subcooling Setpoin G
ESIGN 631
SUBJECT:
_______________________________ ALCULATiON No.
DC W.G. Flournoy
.oN.6072 MAE).H.
Pens yre S
DATE 2/6/80 cKBDAE2/7/80 JO0. NO.
-6 7 MADE a.
ENCLOSURE Justification of RCS Subcooling Setpoint It is assumed that the operator will use the Tsat Meter which is based upon reactor coolant system pressure (400 to 2400 psig) and reactor coolant loop temperature instruments (450 to 700 0 F) to determine the magnitude of subcooling
(-1000 F to +100 0F).
In event of loss of forced cooling or unavailability of the Tsat meter, it is assumed that the operator will rely on incore thermo couples and wide range pressurizer pressure indication in conjunction with a curve based on the 1967 ASME Steam Tables to determine the magnitude of subcooling.
Uncertainties associated with each of these methods for both normal and post-accident environments are determined below:
I Tsat Meter A.
Errors in Hot Leg Temperature (Range from 450 to 700 0 F):
o Process measurement error
+/-10 0 F (Note 1) o RTD accuracy (Specified accuracy of
=
+/-0.25% of span Weed #2004 RDT's)
= +/-0.0025 of 250 0 F
=
+0.625 0 F o
RTD Reference Calibration Data
= +/-0.20 F Accuracy (Note 1) o R/E Converter Accuracy (Analog
=
+/-0.1% of span Devices Model 2B31L)
+/-0.001 of 250 0 F
=
.0.25 0 F o
Accuracy of Decade Resistor used
+/-0.02% of span in R/E Converter Calibration
= +/-0.0002 of 250 0 F (General Radio Instruction
=
+0.05 0 F Manual for Type 1433 Decade Resistor) o Accuracy of Meter used in R/E
+/-0.02% of span Converter Calibration (Dana Manual
=
+/-0.0002 of 250 0 F Publication 980479)
= +/-0.050F o
R/E Converter Drift and Calibration
+/-1.1% of span Tolerance (Note 2 and Instrument
+/-0.011 of 2500 F and Test Procedure S-II-1.20)
= +/-2.75 0F DWG.
NO.
SHEET 3 OF 9
SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET Justification of RCS Subcooling Setpointo
- o.
D 631
SUBJECT:
e)
~
ALft 2
O N.D ra' W.G. Flournoy J.o.NO.
MADEBY P.H. Pensey es DATE cHK.BYoATE 2/7/80
-2 o
Recorder accuracy, drift, calibration =
Not applicable and readout error (Note 3)
Since the above errors are random and independent, they can be combined statistically by taking the square root of the sum of the squares.
Maximum Normal Hot Let Temperature Error=
+l(10)2 + (0.2)2 + (0.25)2 + (0.625)2 + 2(0.05)2 + (2.75)2]1/2 -
+10.4 0 F The R/E converters include compensation for leadwire resistance variation.
The post-accident environment would have a negligible impact on the RTD's and on conversion accuracy (drift of the converter is 5 X 10- 6% per OC).
Maximum Post Accident Environment
= +/-0.1 0F Error (Note 4)
Maximum Total Temperature Error
+/-10.5 0F (Normal Error + environmental error)
B.
Equivalent Saturation Temperature Error from Errors in Reactor Coolant System Pressure (Range from 400 to 2400 psig):
o Transmitter Accuracy
= +/-0.5% of span (Foxboro Technical Manual
= +/-0.005 of 2000 psi PSS2A-1B3A for E11GM Transmitter)
= +/- 10 psi o
Accuracy of Test Gauge
= +/-0.25% of span Used in Transmitter
= +/-0.0025 of 2000 psi Calibration (Heise Test Gauge)
+/- 5 psi o
Accuracy of Meter
= +/-0.02% of span Used in Transmitter
+/-0.0002 of 2000 psi Calibration (Dana Manual
=
+/-0.4 psi Publication 980479) o Transmitter Drift and Calibration
= +/-1.5% of span Tolerance (Note 5 and Instrument
= +/-0.015 of 2000 psi and Test Procedure S-II-1.4)
= +/-30 psi o
I/E Converter Accuracy
= +/-0.1% of span (Instrument and Test
= +/-0.001 of 2000 psi Procedure S-II-1.20)
+ 2 psi o
Accuracy of Meter
= +/-0.02% of span Used in I/E Converter
= +/-0.0002 of 2000 psi Calibration (Dana Manual
= +/-0.4 psi Publication 980479)
DWG. NO.
.E oo 397-B NEW 8/77
SHEET 4
OF 9
SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET Justification of RCS Subcooling SetpointO..
631
SUBJECT:
_NO._DC W.G. Flournoy 6072_H__________esDAT 2/6/80 CRY_____AE278 J.O.NO. 6072 MADE BY PcHK.BY DATE 2/7/80
-3 o
I/E Converter Drift and Calibration
= +/-1.1% of span Tolerance (Note 5 and Instrument
= +/-D.011 of 2000 psi and Test Procedure S-II-1.20)
+/- 22 psi Since the above errors are random and independent, they can be combined statistically by the square root of the sum of the squares.
Maximum Normal Pressure Error =
+ [(10)2 + (5)2 + (30)2 + (2)2 + (22)2 + 2(.4)2] 1/2 = + 38.9 psi Testing of the E11GM transmitters performed by the manufacturer for post-accident conditions indicated that the error associated with increased containment pressures and temperatures is consistently negative with a maximum shift of -6% of span. This is conservative with respect to subcooling determination. However, the maximum post-accident pressure error will be assumed to be +/-6% for conservatism.
Maximum Post-Accident Pressure Error
=
+6% of span (Foxboro Test Report No. T3-1013,
= +/-0.06 of 2000 psi June, 1973, John A. Sears, page 4)
= + 120 psi Maximum Total Pressure Error
=
120 + 38.9 = + 158.9 psi (Normal Error plus Environmental Error)
The error in pressure signal must be converted to an equivalent temperature error at the output of the function generator.
The function generator models the saturated temperatures from the 1967 ASME Steam Tables in the range from 450 to 700oF using three linear approximations for which the maximum positive error (i.e. actual Tsat greater than function generator output) is less than 50F and the maximum negative error is less than 100F. Since negative errors are conservative (i.e. indicated subcooling will be less), the function generator error associated with modeling the Steam Tables will be assumed as +50F.
This error must be combined with the error associated with the maximum reactor coolant system pressure error of +/- 158.9 psi.
The maximum equivalent temperature error is associated with the pressure-temperature slope of the function generator at the Safety Injection Termination pressure of 2000 psig (i.e., 0.07550F/psi) o Equivalent Temperature Error
+/-0.0755 of 158.9 psi associated with Pressure Error
=
+ 12.0oF o
Function Generator Accuracy
= +/-0.1% of span (Instrument and Test Procedure
+/-0.001 of 250 0F S-II-1.20)
=
+0.25 0F DWG.
NO.
SCEOD0397-B NEW 8/77
SHEET 5
OF 9
SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET Justification of RCS Subcooling SetpointESsGN 631
SUBJECT:
C)_ALCULATIONNO.
DC W.G. Flournoy J.0. NO._6072 MADEBY
_PenSreS DATE 2/6/80 CHK.BY DATE 2/7/80
-4 o
Accuracy of Meter Used in
+/-0.02% of span Function Generator Calibration
= +/-0.0002 of 250 0 F (Dana Manual Publication 980479)
+0.05 0F o
Function Generator Drift and
= +/-1.1% of span Calibration Tolerance (Note 5
= +/-0.011 of 2500F and Instrument and Test Procedure
= +2.75 0F S-II-1.20)
The above errors are random and independent and may be combined by the square root of the sum of the squares.
Maximum Saturation Temperature Error at the Output of the Function Generator =
1[(5)2 + (12)2 + (0.25)2 + (0.05)2 + (2.75)2]1/2 = + 13.3 0F C.
Errors in Recorded Subcooling Temperature (Range from -100oF to +100 0F)
Subcooling is determined bycelectricalcombination of the signals from the output of the function generator (Tsat) and the hot leg reactor coolant system temperature in a Summer.
o Accuracy of Summer
=
+1% of span (RN65C Resistors)
=
+/-0.01 of 200OF
=
+20 F o,
Accuracy of Meter Used in
= +/-0.02% of span Summer Calibration (Dana
= +/-0.0002 of 2000 F Manual Publication 980479)
+/-0.040F o
Summer Drift and Calibration
= +/-1.1% of span Tolerance (Note 5 and Instrument
= +/-0.011 of 2000 F and Test Procedure S-II-1.20)
= +2.20F o
Recorder Accuracy (Foxboro
= +/-0.5% of span Technical Bulletin
= +/-0.005 of 200OF TI 220-110)
+/-10F o
Accuracy of Current Meter
= +/-0.02% of span used in Recorder Calibration (Dana
= +/-0.0002 of 200OF Manual Publication 980479)
=
+/-0-.04 0F o
Recorder Drift and Calibration
+/-1.5% of span Tolerance (Note 2 and
= +/-0.015 of 2000F Instrument and Test Procedure
= +/-30F S-II-1.20)
DWG. NO.
MCE 00 3978 NEW 8/77
SHEET 6 OF 9
SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET Justification of RCS Subcooling SetpointDESIGN 631
SUBJECT:
CALCULATION NO.
DC W.G. Flournoy J..NO 6072 MADEB Pens ereS DATE 2/6/80
_CHK.BY
-DATE 2/7/80 o
Recorder readout error
= +/-1/4 of smallest division
= +/-0.25 of 50F
= +/-1.25 0F The above errors, and the errors associated with the hot leg temperature and saturation temperature from the function generator, are random and independent and can therefore be combined by the square root of the sum of the squares.
Maximum Subcooling Error =
+[(10.5)2 + (13.3)2 + (2)2 + 2(.04)2 + (2.2)2 + (1.25)2 + (1)2 + (3)231/2
= +/-17.50 F II Back-up Method using Steam Tables A.
Errors in Core Temperature (Incore Thermocouples -
Range from 320F to 2495 0F. Span will be assumed to be 600 0F) o Thermocouple Reference
+/-3oF Accuracy (Note 1) o Digital Indicator and
= +/-0.02% of span Instrument Accuracy plus +/-0.10 F (Consolidated Controls
= +/-0.0002 of 600oF plus +/-0.1 Model 50GS)
+/-0.20 F o
Drift and Calibration Tolerance
= +/-20 F (Note 5 and Incore Thermocouple plus +/-1% of span Isothermal Calibration results
= +/-2 plus 0.01 of 600 0 F.
per Engineering Prcedure S-V-2.9
= +/-8.0 0F following 1978 refueling outage)
Since the above errors are random and independent, they can be combined statistically by taking the square root of the sum of the squares.
Normal thermocouple error
= +/-1(3)2 + (0.2)2 + (8)2]1/2
=
+8.5 0 F Maximum Post Accident Environment Error (Note 4)
= +/-0.10F Maximum Total Temperature Error
= +/-8.6 0F (Normal Error and Environmental error)
DWG. NO.
SCE 00 397-8 NEW 8/77
SHEET OF' 9 SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET Justification of RCS Subcooling Setpoln DCIG 631
SUBJECT:
J~iicto o
RC Suc lig et inALCUATION NO.
-P-W
_Pzyt W.G. Flournoy J0NO.
6072 MADEBY P.H.
Penseytes DATE 2/6/80 CHK. BYloATE 27/80
-6 B.
Errors in Reactor Coolant System Pressure (Range from 0 to 3000 psig.
Span will be assumed to be 0 to 2500 psig) o Transmitter.Accuracy
= +0.5% of span (Foxboro Technical Manual
= +/-0.005 of 2500 psi PSS2A-1B3A for E11GM Transmitter)
+/- 12.5 psi o
Accuracy of Test gauge used
=
+0.25% of span in Transmitter Calibration
+/-0.0025 of 2500 psi (Heise Test Gauge)
= +/- 6.25 psi o
Accuracy of Current Meter used
=
+0.02% of span in Transmitter Calibration
= +/-0.0002 of 2500 psi (Dana Manual Publication 980479)
+ 0.5 psi o
Transmitter Drift and Calibration
= +/-1.5%
Tolerance (Note 5 and
+0.015 of 2500 psi Instrumentation and Test Procedure
=
+ 37.5 psi S-II-1.4) o Recorder Accuracy
= +/-0.5% of span (Hagan Optimac Instruction
= +0.005 of 2500 psi Bulletin IB-133-101)
= +12.5 psi o
Accuracy of Current Meter used
= +/-0.02% of span in Recorder Calibration (Dana
= +/-0.0002 of 2500 psi Manual Publication 980479)
+ 0.5 psi o
Recorder Drift and Calibration
= +/-2% of span Tolerance (Note 5 and
= +/-0.02 of 2500 psi Instrumenation and Test Procedure
= +/- 50 psi S-II-1.4) o Recorder readout error
=
+1/4 of smallest chart (Station Recorder PR-425) division
+ 25 of 50 psi
+ 12.5 psi Since the above errors are random and independent, they can be combined statistically by the square root of the sum of the squares.
Maximum Normal Pressure Error =
+/-[(6.25)2 + 2(0.5)2 + 3(2.5)2 + (37.5)2 + (50)2]1/2 = +66.4 psi Maximum Post-Accident Pressure Error 6% of span (Foxboro Test Report No. T3-1013,
= +/- 0.06 of 2500 June, 1973, John A Sears, page 4)
+/- 150 psi DWG. NO.
SCE oD 397-6 NEW 8/77
SHEET 8 OF 9
SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET Justification of RCS Subcooling Setpoin tESIGN 631
SUBJECT:
ALCULATION No.
DC X.
J(W.G.
Flournoy J.O. NO.
6072 MADEBY P ense res DATE 2/6/80
_CHK.BY_
DATE 2/7/80 Maximum Total Pressure Error 66.4 + 150 = : 216.4 psi (Normal Error and Environmental error)
At 2000 psig (the Safety Injection Termination Criteria) this pressure error converts to a saturation temperature error of -:16.1 0 F. Operators are instucted to read this temperature from the curve provided with the station procedure (Operating Instruction S-3-4.2).
This curve has 50F subdivisions which can be read to +/- 1/2 division or +/-2.50F Maximum Normal Saturated Temperature Error (as determined from indicated pressure)
= +/-[(16.1)2 + (2.5)2]1/2
+16.3 0 F C.
Errors in Determination of Subcooling Subcooling as determined by the back-up method involves use of a curve provided with Operating Instruction S-3.4.2.
The saturation temperature associated with the indicated pressurizer pressure is determined by entering the curve.
The reactor core temperature is read directly from the incore thermocouples and subtracted from Tsat to determine subcooling. The errors associated with the incore thermocouples and saturated temperature (including errors associated with the curve subdivisions) are random and independent and thus may be combined by the square root of the sum of the squares.
=
[(16.3)2 + (8.6)2]1/2
+ 18.4 0 F Note 1:
Telecon with Dick Miller, Westinghouse Reactor Protection Analysis January 28, 1980 Note 2:
Multi-point calibrations are conducted such than non-linearity is included in the calibration tolerance.
Note 3:
The Tsat Recorder indicates subcooling (Tsat-Thot) directly. Thus, recorder accuracy, calibration, drift and readout error is applicable only for subcooling.
Note 4:
Westinghouse Owner's Group investigations have confirmed that the post-accident environment effect on temperature indication will be small.
(
Reference:
December 27, 1979, letter to EOI Seminar Attendees and Owners' Group Representatives, TMI-OG-132, from R. A. Newton)
DWG. NO.
SHEET 9
OF 9
SHEETS ENGINEERING DEPARTMENT CALCULATION SHEET Justification of RCS Subcooling Setpoint6ESIGN
SUBJECT:
CALCULATION NO.
DC_631
,?WW.
G. Flournoy J.o. N O.6072 MADEBY P.H. Pense es DATE 2/6/80 CHK. B G
oDATE 2/7/80
-8 Note 5:
Instrument drift is assumed to be 1% of span and is added arith metically to calibration tolerance before being combined statistically by the square root of the sum of the squares. These assumptions are consistent with the Westinghouse Owners' Group recommendations contained in the reference included with Note 4 above.
PHPenseyres:mpp DWG. NO.
5CE 0D 397-9 NEW 8/77