ML19257D052
| ML19257D052 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 01/25/1980 |
| From: | Miller D PORTLAND GENERAL ELECTRIC CO. |
| To: | Ross D Office of Nuclear Reactor Regulation |
| References | |
| TAC-12398, NUDOCS 8001310282 | |
| Download: ML19257D052 (7) | |
Text
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. r~ :~ F January 25, 1980 Trojan Nuclear Plant Docket 50-344 License NFF-1 Director of Nuclear Reactor Regulation ATTN:
Mr. Denwood F. Ross, Jr., Acting Director Division of Project Management U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Sir:
In response to your December 27, 1979 le:ter to C. Reed (Westinghouse Owners' Group) regarding modification of small-break Loss-of-Coolant Accident (LOCA) operator guidelines, we have reviewed your concerns about the auxiliary feedwater flow criteria and instrument errors associated with safety injection termination based upon core subcooling.
A review of the auxiliary feedwater flow criteria has indicated that the revised criteria, which is based on auxiliary feedwater flow to remove decay heat after 20 min. following reactor trip, do not conf.ict with other operational restrictions in force on auxiliary feedwater/
steam generator operations at Trojan. Because of the feedline piping configuration and feedring J-tubes, feedline water hammer is not a problem at Trojan. The Trojan plant Emergency Instructions will be revised in light of these revised NRC criterie, and necessary param-eters for instrument setpoints will be incorporated in the Emergency Instructions.
With regard to HPI termination, Portland General Electric Company (PGE) is a participant in the Westinghoss.e Owners' Group responding to IMI-related changes to standard emergency operating instructions. As such, we used a calculational methodology developed by the Owners' Group to establish instrument setpoints. The attachment developes the instrument setpoints appropriate for the Trojan plant.
For LOCA events, these setpoints will be incorporated in the appropriate Emergency Instructions.
"ith regard to the HPI termination for non-LOCA events, the transients
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Mr. Denwood F. Ross, Jr.
Janua ry 25, 1980 Page 2 and Emergency Instructions are currently being reviewed by the Westing-house Owners' Group for a subcooling criteria. These activities will be completed and transmitted to the NRC by the Westinghouse Owners' Group within the 21-day requirement.
Your December 27 letter also requested utilities to provide a commitment to install instrumentation and readout devices for determination of actual subevcling condition. As we indicated in the PGE letter on January 2, 1980 in response to the TMI Short-Term Lessons Lesrned, we have installed the subcooling margin monitors at the Trojan plant.
Therefore, no additional commitment for subcooling instrumentation is necessary in the long term.
We are currently reviewing emergency power supplies per IE Bulletin 79-27.
The availability of sufficient instrumentation for operator actions defined in the Emergency Instructions in case of loss of power supply will be addressed in our response to the subject Bulletin.
Sincerely, s
Q'. br
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g D. R. Miller Assistant Vice President System Engineering-Construction DRM/DIH/KM/4sa5A6 Attachments c:
Mr. Lynn Frank, Director State of Oregon Department of Energy Mr. A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors U. S. Nuclear Regulatory Commission 1841 324
Page 1 of 5 ATTACHMENT 1 INSTRUMENT SETPOINTS SAFETY INJECTION TERMINATION The Westinghouse Owners' Group example calculation furnished by Point Beach provides the methodology for Trojan's calculation with the exception that the transmitter drift and calibration accuracy are added arithmetically before being statistically combined by the square root of the sum of the squares method.
I.
Errors in Indicated Pressure (assuming narrow range pressure used from main control board)
Normal Transmitter Overall Accuracy 1 75% span (Barton 393 Tech Manual) 1 0075 of 800 psi 16 psi Normal Transmitter Repeatability 1 2% span (Barton 393 Tech Manual) 11.6 psi Accuracy of Pressure Gauge for Calibration 1 1% span (Heis Tech Manual) 1 001 of 2500 psi 12.5 psi Accuracy of Current Meter for Heise Gauge 1 12% span (Fluke 8120 or 8600 Tech Manual) 13 psi Allowed Calibration Tolerance 1 5% span (Trojan Calibration Data Sheets) 1 005 of 800 psi 14 psi Ambient Temperature Effects on Transmitter 11% span (Dick Miller, Westinghouse Reactor
-+.01 of 800 psi Protection Analysis, Telecon 1-15-80) 18 psi Maximum Transmitter Drift 11% span (Westinghouse Owners' Group) 1 01 of 800 psi 18 psi Normal Isolator Accuracy 1 5% span (W Accuracy Document) 1 005 of 800 psi 14 psi Normal Indicator Accuracy 11.5% span (W Accuracy Document, VX-252) 1 015 of 800 psi 112 psi Ambient Temperature Effects on Instrument 1 5% span (Westinghouse Owners' Group, assume OK 1 005 of 800 psi for Hagan)
+4 psi Maximum Indicator Reading Error 11/2 smallest division (Gary Bair, Trojan Reactor Engineer) 1 5 of 20 psi 110 psi
) b 's
Page 2 of 5 Maximum Normsl Instrument Error =
= Y(4 + 8)2 + (6)2 + (2.5)2 + (3)2 + (1.6)2 + (8)2 + 2(4)2 + (12)2 + (10)2
= 123.2 psi Maximum Post-Accident Environmental Error
= +5% of test pressure for Transmitter
= +.05 of 2030 psi (Westinghouse Owners' Group, negative allow
= +102 psi positive)
Maximum Total Pressure Instrument Error = normal error + environmental error in Adverse Environment
= 23.2 psi + 102 psi
= 125.2 psi II.
Errors in Indicated Temperature (assuming T-hot from strip charts, computer or core-exit thermocouples)
A.
TH Wide Range Instrument Process Measurement Error
= +3% span (Dick Miller, Westinghouse Reactor
- I.03 of 700*F Protection Analysis, Telecon 1-15-80)
={21*F RTD Reference Calibration Curve Accuracy
= 1 25% span (supplier date MIT-15-1-6)
= +.0025 of 700*F
={1.75'F Accuracy of Current Meter
= +.04 span (Fluke Tech Manual)
= T.0004 of 700*F
=[.3*F Allowed Calibration Tolerance
= +.5% span (Trojan calibration data)
= T.005 of 700*F
={3.5'F Calibration Error Due to Non-Linearity
= 1 5% span (Westinghouse Owners' Group)
= +.005 of 700*F
= +3.5*F Normal RIT Accuracy
= +.5% span (MIT-15-16 Tech Manual)
= +.005 of 700*F
=[3.5*F Normal Isolator Accuracy
= 1 5% span (MIT-15-1-6 Tech Manual)
= +.005 of 700*F
={3.5*F Ambient Temperature Effects on
= +.005 of 700 F
= +.5% span Instrument (Westinghouse Owners' Group)
= +3.5*F Maximum Instrument Drift
= +1.0% span (Westinghouse Owners' Group)
={.01of700*F
= +7'F f841 326
Page 3 of 5 Strip Chart Recorder Error
= +.5% span (Hagan Tech Manual) (If Applicable)
= +.005 of 700*F
= +3.5*F Operator Readout Error on Recorder
= +1/2 smallest division (Cary Bair, Trojan Reactor Engineer)
= +.5 of 10*F
= +5 F Digital Display Error of Computer
= +.25% span (Gary Bair, Trojan Reactor Engineer)
= +.0025 of 700*r (If applicable)
+1.8*F Maximum Normal Temperature (T ) Error
H
= d(3.5 + 7)2 + (21)2 + (1.75)2 + (0.3)2 + 4(3.5)2 + - (5)2, + [(3.5)2
,(1.8)2 L(0)2
= '125.3*F strip chart
- 124.6*F digital readout Maximum Post-Accident Environment Error
= error of 2 junction boxes (Westinghouse Owners' Group, assume OK
= 1 01% of 700*F for Hagan)
= +.l*F Maximum Total Temperature (T ) Error = normal error + environmental error H
(in adverse environment) 125.4*F strip chart 124.7'F digital readout B.
Thermocouples at Core Exit Thermocouple Reference Accuracy
= 13*F (MIT-11-172-1, Tech Manual)
Calibration Accuracy (MIT-11-172-1,
= 13*F Tech Manual and Calibration Data Sheets)
Digital Display Error of Computer
= 1 25% span (Gary Bair, Trojan Reactor Engineer)
= +.0025 of 2300*F (If applicable)
= +5. 7 5'F Maximum Instrument Drift
= +1% span (Westinghouse Owners' Group)
= +.01 of 700*F
= +7"F 1/ (3)2 + (5.75)2 + (7)2 2
Maximum Normal Thermocouple Error =
= 110.0*F Maximum Post-Accident Environment Error = error equiv. to 2 junction boxes (Westinghouse Owners' Group, assume
= 1 01% of 700*F OK for Hagan)
= +.l*F Maximum Total Thermocc-le
= normal 6 environment errors Temperature Error
= +10.1*F (in adverse environment)
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Page 4 of 5 III.
Calculation of Subcooling Margin After Consideration of Instrument Errors A.
Under Normal Environmental Condition Assume indicated pressure = 2000 psig Minimum absolute pressure = 2015 psia - 23.2 psi
= 1991.8 psia TSAT (1991.8 psia) = 635.2*F Indicated temperature to ensure subcooling at minimum pressure iTSAT (min P) - max normal temp error r25.3 1635.2-h 24.6 L10.0 609.9 (TH strip chart) i<[610.6 (T H digital)
$625.2 (core exit thermocouple)
The indicated subcooling = TSAT (indicated pressure) - indicated temp.
,609.9
= 636.9
/ 610.6 L625.2 27.0 (TH strip chart) 26.3 (TH digital)
=
11.7 (core exit thermocouple)
B.
Under Adverse Environment (LOCA and Steam Line Break Inside Containment)
Assume indicated pressure = 2000 psig Minimum absolute pressure = indicated pressure - maximum error 2015 psia - 125.2 psi
= 1889.8 psia TSAT (1889.8 psia) = 627.8"F Indicated temperature to ensure subcooling at minimum' pressure
= TSAT (min P) - maximum temp error
= 627.8*F - 2.7'F r
10.l*F
[602.4*F (TH strip chart)
=1 603.l*F (TH digital) 617.7*F (core exit thermocouple)
Page 5 of 5 The indicated subcooling = TSAT (indicated P) - indicated temperature r 602.4*F
= 636.9'T -
603.1*F
-617.7'F 34.5'F (Til strip chart)
'33.8*F (Til digital)
=
19.2*F (core exit thermocouple)
NOTE: The required subcooling in the Emergency Instructions will be at least as much as the above " indicated subcooling".
1841 329 GCB/KM/4sa5A12