ML12125A308
| ML12125A308 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 05/02/2012 |
| From: | Entergy Operations |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| RBG-47236 G13-18.3.1-005, Rev 0 | |
| Download: ML12125A308 (13) | |
Text
[] ANO-1 [I ANO-2 EIGGNS El IP-2 [] IP-3 [1 PLP F JAF I]PNPS E RBS LI VY L] W3 El NP-GGNS-3
[INP-RBS-3 CALCULATION EC # LAR (2)Page 1 of 12 COVER PAGE (3) Design Basis Cate. E] YES [] NO (4) E] CALCULATION
[]EC Markup Calculation No: G13.18.3.1-005 (6) Revision:
0 (7) Title: Degraded Voltage Relay Setpoints for E22-S004 (8) Editorial DYES E NO (9) System(s):
302 (10) Review Org (Department):
Electrical Design Engineering (1) Safety Class: (12) Component/Equipment/Structure Type/Number:
Z Safety / Quality Related E Augmented Quality Program E22-S004-ACB4-62S5 E22-S004-ACB4-62S6 LI Non-Safety Related E22-S004-27N 1 E22-S004-27N2 (1 3) Document Type: F43.02 (14) Keywords (Description/Topical Codes): degraded voltage relay, setpoint, GE setpoint methodology REVIEWS s Name/Signature/Date (6) Name/Signature/Date (7) Name/Signature/Date Charles Blackledge/See IAS Greg Svestka/See IAS Jason Arms/See IAS Responsible Engineer [ Design Verifier Supervisor/Approval
[ Reviewer El Comments Attached El Comments Attached SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT
______ RIVER BEND STATION Pe 2~PAGE 2 OF 13 ENTERGY CALCULATION REFERENCE ICALCULATION NO: G 13.18.3.1-005 SHEET REVISION:
0 I. EC Markups Incorporated (N/A to NP calculations)
- 1. None II. Relationships:
Sht Rev Input Output Impact TrackingNo.
Doc Doc Y/N 1. STP-302-1604
-- 21 0 R1 Y 2. STP-302-1605
-- 25 2 0 Y 3. G13.18.6.2-ENS*004 0 001 2 0 N EC-27437 4. G13.18.6.2-ENS*007 0 001 2 0 N EC-27437 5. G13.18.3.6*016
-- 002 R] 0 N EC-31715 6. G13.18.3.1*002
-- 003 2 0 Y 7. RBS Technical Specifications Table -- 0 0 Y 3.3.8.1-1 8. RBS Technical Requirements Manual 0 0 Y Table 3.3.8.1-1 I1. CROSS
REFERENCES:
IV. SOFTWARE USED: N/A Title: Version/Release:
Disk/CD No.V. DISK/CDS INCLUDED:
N/A Title: Version/Release Disk/CD No.VI. OTHER CHANGES:
SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT Rev. 0 RIVER BEND STATION Rev. 1~PAGE 3 OF 13 Revision Record of Revision.:
Initial issue.0 LAR The purpose of this calculation markup is to provide the Degraded Voltage Submittal Relay NO-LOCA time delay and Loss of Voltage Relay dropout voltage setpoints, and Technical Specification and TRM limits.+U SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT Rev. 0 RIVER BEND STATION PAGE 4 OF 13 ENTERGY.5.0 6.0 7.0 8.0 9.0 10.0 TABLE OF CONTENTS PURPO SE .........................................................................................................................................................................
5 CO NCLUSIO NS ...............................................................................................................................................................
5 IN PUT AN D DESIG N C RITERIA ..................................................................................................................................
5 A SSUM PTIO NS ...............................................................................................................................................................
7 CALCULATIO N M ETH O DO LO G Y ..............................................................................................................................
7 CALCULATIO N ..............................................................................................................................................................
8 SETPOINT CALCULATION ENGINEERING DEPARTMENT RIVER BEND STATION G13.18.3.1-005 Rev. 0 PAGE 5 OF 13 ENTERGY 5.0 Purpose The purpose of this calculation markup is to provide the Degraded Voltage Relay NO-LOCA time delay and Loss of Voltage Relay dropout voltage setpoints, and Technical Specification and TRM limits.6.0 Conclusions The following table shows the new revised Technical Specification limits.Specification Existing Values Revised Values T.S. 3.3.8.1-1 2a >_ 2831 V and< 3259 V >3019 V and< 3325 V T.S. 3.3.8.1-1 2d > 53.4 s and:< 66.6 s > 44.7 s and5 <54.83 s TRM 3.3.8.1-1 2a > 2892 V and< 3198 V > 3158 V TRM 3.3.8.1-1 2d > 54 s and< 66 s 5 50.49 s 7.0 Input and Design Criteria 7.1. Div 3 Degraded Voltage Relays (Voltage Function)Relay: E22-S004-ACB4-62S5 E22-S004-ACB4-62S6 E22-S004-27N1 E22-S004-27N2 E22-S004-ACB4-62S5 E22-S004-27N1 Input E22-S004-ACB4-62S6 E22-S004-27N2 Reference Document G 13.1I8.6.2-ENS*007 Loop Uncertainty (LU) +/-5.622 s 3.678 V G13.18.6.2-ENS*004 G13.18.6.2-ENS*004 G 13.18.6.2-ENS*007 Total Loop Uncertainty (TLU) +/-5.99 s 5.31 V G13.18.6.2-ENS*004 Max. Loop Setting Tol. (CTL) +/-3 s 2.61 V G13.18.6.2-ENS*007 G13.18.6.2-ENS*004 Current Setpoint 54.9s 87 V G13.18.6.2-ENS*007 G 13.18.6.2-ENS*004
7.2. Analytical
Limits For E22-S004-ACB4-62S5 and E22-S004-ACB4-62S6 Analytical Limit = 60 s (Ref: G 13.18.3.6*016)
For E22-S004-27N1 and E22-S004-27N2 Analytical Limit = 2935 VAC Maximum dropout for the Loss of Voltage Relays = 3351 VAC SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT Rev; 0 RIVER BEND STATION PAGE 6 OF 13 ENTERGY 7.3. Bus to Relay Voltage Conversion The Division 3 Degraded Voltage bus (4160 kV) to relay input voltage conversion factor is (35) (Ref: G13.18.6.2-ENS*004 and G13.18.6.2-ENS*007).
7.4.Output Documents (Any Changes to the data, analyses, or conclusions of calculation G13.18.3.1-005 may impact the following RBS documents) 7.4.1. RBS Technical Specification and Technical Requirements Manual 7.4.1.1 TS 3.3.8.1, Loss of Power (LOP) Instrumentation.
7.4.1.2 TR 3.3.8.1, Loss of Power (LOP) Instrumentation.
7.4.2. Procedures
7.4.2.1 STP-302-1605, HPCS DEGRADED VOLTAGE CHANNEL CALIBRATION AND LOGIC SYSTEM FUNCTIONAL TEST.7.4.2.2 STP-302-1604, HPCS LOSS OF VOLTAGE CHANNEL CALIBRATION AND LOGICSYSTEM FUNCTIONAL TEST.7.5. Operating Experience CR-RBS-2011-04838:
CR-RBS-2011-04838 documented non-conservative Technical Specification for Degraded Voltage Relay NO-LOCA time delay and Loss of Voltage Relay dropout setpoints.
The condition report documented that the existing limits do not protect the RBS motors against sustained degraded voltage conditions for a long period of time.Disposition:
This engineering change markup has been issued to provide revised Technical Specification and TRM setpoint limits for the Degraded Voltage Relay NO-LOCA time delay and Loss of Voltage Relay dropout setpoints.
The new setpoint limits provided within this markup will ensure that the RBS motors are protected against sustained undervoltage and degraded voltage conditions.
SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT Rev. 0_ RIVER BEND STATION PAGE 7 OF 13 ENTERGY 8.0 Assumptions 8.1. The Limiting Operating Transient Variation (XT) is assumed to be equal to the minimum voltage observed on the associated bus during a LOCA transient at the Lower Analytical Limit for the Degraded Voltage Relays (See calculation G13.18.3.6*016).
Thus, the setpoint should be such that the Loss of Voltage relays do not dropout during a degraded grid LOCA transient.
The Limiting Operating Transient Variation (XT) is given by the following equations (Ref: EN-IC-S-007-R): The minimum voltage during a transient is observed for Division I bus. This voltage is 3351 VAC (Section 7.2). Therefore, XT = 3351 /(35) = 95.75 VAC (Ref: Section 7.3 for bus to relay voltage conversion).
8.2. The LU, TLU and reset differential, derived in calculation G13.18.6.2-ENS*004 and G13.18.6.2-ENS*007 (EC-27437), are calculated using instrument uncertainties that are based on % setting (%setpoint).
Because the proposed setpoints are different from the existing, those uncertainties will increase.
Therefore, this calculation will adjust the LU, TLU and reset differential values proportionally according to the increase in setpoint.9.0 Calculation Methodology The methodology used in this calculation is in accordance with the "Instrument Loop Uncertainty
&Setpoint Calculations" (Ref: EN-IC-S-007-R) and "General Electric Instrument Setpoint Methodology" (Ref: 7224.300-000-0011B).
The Allowable Values (AV) and Nominal Trip Setpoints (NTSP2) for the setpoints considered in this calculation have both upper and lower limits. The Lower Limit (AV MIN) is calculated for the Degraded Voltage Relay NO-LOCA time delay by subtracting the difference between the AV MAX and the NTSP2 from the NTSP2. Then an additional margin of 3% is applied to give the final value of AV MIN. The Upper Limit (AV MAX) is calculated for the Loss of Voltage Relay Dropout by adding the difference between the NTSP2 and AV MIN to the NTSP2. An additional margin of 3% is applied to give the final value of AV MAX. Spurious trip avoidance analysis will ensure that these relays, if found drifted in the upper/lower limit not calculated, will not trip under unanalyzed conditions.
The upper AV for the Degraded Voltage Relay NO-LOCA time delay (AV MAX) must be below the upper Analytical Limit (AL) minus the absolute value of the positive Loop Uncertainty (LU). The lower AV for the Loss of Voltage Relay Dropout (AV MIN) must be above the lower AL plus the absolute value of the negative LU.Upper AV: <Upper AL -I +LUI Lower AV > Lower AL + I -LUI The upper NTSP2 must be below the upper AL minus the absolute value of the positive Total Loop Uncertainty (TLU). The lower NTSP2 must be above the lower AL plus the absolute value of the negative TLU.
SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT Rev. 0______ RIVER BEND STATION PAGE 8 OF 13 ENTERGY Upper NTSP2 < Upper AL -I +TLU Lower NTSP2 > Lower AL + I -TLU I The Loop Uncertainties and Total Loop Uncertainties used as input to this calculation are developed in the Loop Uncertainty Determination calculation (Ref: G 13.18.6.2-ENS*004 and G 13.18.6.2-ENS*007 EC-27437) using the methodologies provided in EN-IC-S-007-R and 7224.300-000-001B.
The Maximum Loop Setting Tolerance (CTLV) provides the tolerance for the desired setpoint of the relay.This tolerance is irrespective of the setpoint chosen and is, therefore, the same for the dropout and the reset values. The minimum and maximum for the Desired/TRM allowable value is calculated as follows: Desired Max. = Desired/TRM Trip Value + CTLV Desired Min. Desired/TRM Trip Value -CTLV 10.0 Calculation 10.1. Degraded Voltage Relay No-LOCA time delay relay The setpoint for the relays is calculated iteratively as the LU and TLU are proportional to the setpoint.The final Nominal setpoint (NTSP2) calculated iteratively is 50.49 s.The following calculations below provide the calculated STP, Allowable Value and Nominal Trip Setpoints (NTSP2). A margin of 4 s is used for LER Avoidance LU = 5.622 x New Setpoint/Current Setpoint LU = 5.622 x 50.49/54.9
= 5.17 s TLU = 5.99 x 50.49/54.9
= 5.51 s AVMAX<Upper AL -I+LUI =60-5.17=54.83 s AV MIN > (NTSP2 -(AV MAX -NTSP2)) x 0.97 = (50.49 -(54.83 -50.49)) x 0.97 = 44.7 s (rounded down)NTSP2 (TRM) _ Upper AL -I +TLU I -LER Avoidance Margin = 60 -5.51 -4 = 50.49 s STP MIN = NTSP2 -ICTLI = 50.49 -3 = 47.49 s STP MAX = NTSP2 + CTLI = 50.49 + 3 = 53.49 s 10.2. Loss of Voltage Relay The setpoint for the relays is calculated iteratively as the LU and TLU are proportional to the setpoint.The final Nominal setpoint (NTSP2) calculated iteratively is 90.24 VAC.The following calculations below provide the calculated STP, Allowable Value and Nominal Trip Setpoints (NTSP2). A margin of 0.865 V is used for LER Avoidance.
For LU, Calculation SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT RIVER BEND STATION Pe 9-,. PAGE 9 OF 13 ENTERGY G13.18.6.2-ENS*004 shows an additional margin of 1.392. This margin is removed in this setpoint calculation.
LU = (3.678-1.392) x New Setpoint/Current Setpoint LU = (3.678-1.392) x 90.24/87 = 2.37 VAC TLU = 5.31 x 90.24/87 = 5.51 VAC AV MIN > Lower AL + I +LU I = 2935 /(35) + 2.37 = 83.86 + 2.37 = 86.23 VAC (rounded up)AV MAX < (NTSP2 + (NTSP2 -AV MIN)) x 1.03 = (90.24 + (90.24 -86.23)) x 1.03 = 97.08 VAC 97.08 VAC x 35 = 3397.8 VAC Since AV MAX is calculated to be 3397.8 VAC, which is not within the Limiting Operating Transient Variation (assumption 8.1) for the Loss of Voltage Relays (3351 VAC), AV MAX will be chosen to be 3325 VAC to provide adequate margin to the Limiting Operating Transient Variation for the Loss of Voltage Relays.NTSP2 (TRM) > Lower AL + I +TLU I + LER Avoidance Margin = 83.86 + 5.51 + 0.865 = 90.24 VAC (Rounded Up)STP MIN = NTSP2 -ICTLI = 90.24 -2.61 = 87.63 VAC STP MAX = NTSP2 + ICTLI = 90.24 + 2.61 = 92.85 VAC SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT Rev. 0_____ RIVER BEND STATION PAGE10OF13 ENTERGY 10.3. Margin Checks: 10.3.1. Spurious Trip Avoidance Test The Spurious Trip Analysis is performed to demonstrate the acceptability of the calculated Nominal Trip Setpoint.
The Nominal Trip Setpoint should provide at least 95% probability that a spurious trip will not occur. The value calculated for Z should be = 1.645 to achieve the 95% criteria.Spurious Trip Equation (Ref: EN-IC-S-007-R):
= INTSP2 -XT1 V(4 )2+( ,)2 Where: NTSP2 XT UAM= Calculated Nominal Trip Setpoint, Upper= Limiting operating transient=.standard deviation for the operating transient (equal to zero when the limiting operating transient is based on documented operating conditions).
=0= standard deviation of the NTSP2= ~iJ~I(A)2
+ (CL )2 +(L 2 + (pA. ) 2 + (p)The Total Loop Uncertainty is defined in EN-IC-S-007-R as: TLU=- +/-(Lýh>(A, )2 + (CL )2 + (DL )2 + (pA.I)2 + (pE)2 AL = Total random uncertainty that makes up the loop from device (provided in GI 3.18.2.3-ENS*002 and G013.18.2.3-ENS*006 EC-27437)AN = The loop from device uncertainty for normal conditions (i.e. AL determined for normal conditions)
= AL > AN Since a higher value of cy, reduces the spurious trip avoidance probability, it is conservative to assume that AN = AL for the equation for standard deviation.
SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT Rev. 0_____ RIVER BEND STATION PAGE 11 OF 13 ENTERGY= ~ I~!~/()2 (C)2 (D)2 + (pM)2 +(pE)Since, TL U as provided in G13.18.6.2-ENS*004 and G 13.18.6.2-ENS*007, contains the same random component, -(AL) + (CL)2 + (DL )+2(P)- +(PE) for both positive and negative direction, cri = +TLUI/ n In = 1.645 (for Loss of Voltage relay)= 2 (for Degraded Voltage Relay No-LOCA time delay)5.51 / 1.645 V= 3.35 V (for Loss of Voltage Relay)= 5.51 / 2 s (for Degraded Voltage Relay No-LOCA time delay; used in Section 10.3.2.1)= 2.755 s (for Degraded Voltage Relay No-LOCA time delay)10.3.1.1 Degraded Voltage Relay No-LOCA time delay relay Spurious trip avoidance test for the time delay is bounded by the spurious trip avoidance for the Loss of Voltage relay dropout setpoint.
The purpose the Loss of voltage relays is to ensure that the RBS safety related motors will not experience less than 70% terminal voltage.The time delay ensures that, if such a condition occurs, the degraded voltage relay trips in less than 60 seconds. This condition is based on the analysis provided in calculation G 13.18.3.6*016.
There are no other conditions that are dependent upon the Time Delay function of the relay. However, a spurious trip avoidance test for the Loss of Voltage relays is required to ensure that the relays do not dropout during worst case LOCA transient conditions.
10.3.1.2 Loss of Voltage relay The Spurious Trip Analysis is performed to demonstrate the acceptability of the calculated Nominal Trip Setpoint.
The Nominal Trip Setpoint should provide at least 95% probability that a spurious trip will not occur. The value calculated for Z should be = 1.645 to achieve the 95% criteria.NTSP2 = Calculated Nominal Trip Setpoint= 90.24 V (Per Section 10.2)
SETPOINT CALCULATION ENGINEERING DEPARTMENT RIVER BEND STATION G13.18.3.1-005 Rev. 0 PAGE 12 OF 13 ENTERGY XT= Limiting operating transient= 95.75 V (Per Assumption 8.1.1)= standard deviation for the operating transient (equal to zero when the limiting operating transient is based on documented operating conditions).
=0=+TLU/m= 1.645= 5.51 / 1.645 V= 3.35 V (-/m o-1 Spurious Trip Calculation:
ZT = 190.24-95.751
((0)2 + (3.35)2)/2
= 1.6448 The calculated value for ZT is approximately 1.645. Therefore the calculated Nominal Trip Setpoint is acceptable.
10.3.2. LER Avoidance Analysis: LER avoidance analysis is performed to determine the acceptability of the margin between the calculated Nominal Trip Setpoint and the calculated Allowable Value. The margin should provide at least a 90% probability the instrument channel's trip setpoint will not exceed the allowable value. The calculated value for ZLER should be > 1.28.LER Avoidance Equation (Ref: EN-IC-S-007-R):
ZLER IA V -NTSP21 a7 1 Where: AV = Allowable Value NTSP2 = Calculated Nominal Trip Setpoint a 1= standard deviation of the NTSP SETPOINT CALCULATION G13.18.3.1-005 ENGINEERING DEPARTMENT Rev. 0 RIVER BEND STATION PAGE 13 OF 13 ENTERGY 10.3.2.1 Degraded Voltage Relay No-LOCA time delay relay ZLER= 150.49 -54.831 2.755= 1.575 10.3.2.2 Loss of Voltage relay ZLER= 186.23-90.241 3.35= 1.20 The LER Avoidance value for Degraded Voltage relay No-LOCA time delay is not greater than 1.28. However, the LER avoidance for Loss of Voltage relay is 1.20 which yields a probability of 88.5%. The STP limits on the relays ensure that the relays will not drift beyond the acceptable STP values.The calculated values for ZLER (upper and lower) are deemed acceptable and demonstrate sufficient probability for LER avoidance.