ML12125A307
| ML12125A307 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 05/02/2012 |
| From: | Entergy Operations |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| RBG-47236 G13.18.3.1-004, Rev 0 | |
| Download: ML12125A307 (13) | |
Text
Attachment 2 RBG-47236 Calculations G13.18.3.1-004 G13.18.3.1-005 G 13.18.6.2-ENS*002 G13.18.6.2-ENS*004 G 13.18.6.2-ENS*006 G13.18.6.2-ENS*007 El ANO-1 [-I ANO-2 [] GGNS El IP-2 El IP-3 EL PLP] JAF -]PNPS I RBS El VY El W3 EL NP-GGNS-3
--NP-RBS-3 CALCULATION 1)EC # LAR (2)Page 1 of 12 COVER PAGE (3) Design Basis Cale. E] YES [] NO (4) E] CALCULATION Z] EC Markup (5) Calculation No: G13.18.3.1-004 (6) Revision:
0 7 Title: Degraded Voltage Relay Setpoints for ENS-SWGO1A and ENS- (8) Editorial SWG01B [i YES IZNO (9) System(s):
302 (10) Review Org (Department):
Electrical Design Engineering (i" Safety Class: (12) Component/Equipment/Structure Type/Number:
[] Safety / Quality Related Z aey/ ult RltdENS-SWGI1A-62-2 ENS-SWGI1B-62-2 LI Augmented Quality Program ENS-SWG 1A-2-1 ENS-SWGIB-2-1 El Non-Safety Related ENS-SWG1A-27-1A, 1B, 1C ENS-SWG1B-27-1A, IB, 1C 1 1 3) Document Type: F43.02 (14) Keywords (Description/Topical Codes): degraded voltage relay, setpoint, GE setpoint methodology REVIEWS (15) Name/Signature/Date (16) Name/Signature/Date (17) Name/Signature/Date Charles Blackledge/See IAS Greg Svestka/See IAS Jason Arms/See IAS Responsible Engineer [ Design Verifier Supervisor/Approval Z Reviewer El Comments Attached El Comments Attached SETPOINT CALCULATION ENGINEERING DEPARTMENT RIVER BEND STATION G13.18.3.1-004 Rev. 0 PAGE 2 OF 12 ENTERGY CALCULATION REFERENCE CALCULATION NO: G13.18.3.1-004 SHEET REVISION:
0 I. EC Markups Incorporated (N/A to NP calculations)
- 1. None II. Relationships:
Sht Rev Input Output Impact Tracking No.Doc Doc Y/N 1. STP-302-1600
-- 20 E l Y 2. STP-302-1601
-- 20 0 0 Y 3. STP-302-1602
-- 23 0 0 Y 4. STP-302-1603
-- 24 0 0 y 5. G13.18.6.2-ENS*002 0 002 [0 N EC-27437 6. G13.18.6.2-ENS*006 0 001 0 0 N EC-27437 7. G13.18.3.6*016
-- 002 01 0 N 8. G13.18.3.1*001
-- 003 0] 10 Y 9. RBS Technical Specifications Table -- 0 0 Y 3.3.8.1-1 10. RBS Technical Requirements Manual 10 0 Y Table 3.3.8.1-1 III. 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 G13.18.3.1-004 ENGINEERING DEPARTMENT Rev. 0 RIVER BEND STATION PAGE 3 OF 12 ENTERGY R..evision 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.
.SETPOINT CALCULATION G13.18.3.1-004 ENGINEERING DEPARTMENT OR____ RIVER BEND STATION Pe 4~PAGE 4 OF 12 ENTERGY TABLE OF CONTENTS 5.0 PURPO SE .........................................................................................................................................................................
5 6.0 CO NCLUSIO NS ...............................................................................................................................................................
5 7.0 INPUT AND DESIG N CRITERIA ..................................................................................................................................
5 8.0 ASSUM PTIO NS ...............................................................................................................................................................
7 9.0 CALCULATIO N M ETH O DO LO GY ..............................................................................................................................
7 10.0 CALCULATIO N ..............................................................................................................................................................
8 SETPOINT CALCULATION G13.18.3.1-004 ENGINEERING DEPARTMENT
______ RIVER BEND STATION Pe 5*TRPAGE 5 OF 12 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 la >2850 V and < 3090 V > 3005 V and: <3302 V T.S. 3.3.8.1-1 Id > 53.4 s and < 66.6 s > 46.59 s and < 57.07 s TRM 3.3.8.1-1 la >2910 Vand< 3030 V > 3105 V TRM 3.3.8.1-1 ld > 54 s and< 66 s < 52.55 s 7.0 Input and Design Criteria 7.1. Div 1 and 2 Degraded Voltage Relays (Voltage Function)Relay: ENS-SWGIA-62-2 ENS-SWG1A-27-1A, 1B, IC ENS-SWG 1 B-62-2 ENS-SWG1B-27-1A, 1B, IC ENS-SWG1A-62-2 ENS-SWG1A-27-1A, 1B, IC Input ENS-SWG1B-62-2 ENS-SWG1B-27-1A, 11B, 1C Reference Document Loop Uncertainty (LU) +/-3.22 s 0.8675 V G13.18.6.2-ENS*006 G13.18.6.2-ENS*002 Total Loop Uncertainty (TLU) +/-3.795 s 1.019 V G13.18.6.2-ENS*006 G 13.18.6.2-ENS*002 G 13.1 8.6.2-ENS*006 Max. Loop Setting Tol. (CTL) +/-3 s 0.87 V G13.18.6.2-ENS*002 G 13.18.6.2-ENS*002 Current Setpoint 57.8 s 49 V G13.18.6.2-ENS*0O6 G13.18.6.2-ENS*002
7.2. Analytical
Limits For ENS-SWG 1 A-62-2 and ENS-SWG 1 B-62-2 Analytical Limit = 60 s (Ref: G 13.18.3.6*016)
For ENS-SWG1A-27-1A, IB, IC and ENS-SWGIB-27-1A, IB, IC Analytical Limit = 2950 VAC (Ref: G 13.18.3.6*016)
Maximum dropout for the Loss of Voltage Relays = 3318.27 VAC SETPOINT CALCULATION G13.18.3.1-004 ENGINEERING DEPARTMENT Is____ RIVER BEND STATION Pe 6 NPAGE 6 OF 12 ENTERGY 7.3. Bus to Relay Voltage Conversion The Division I & 2 Degraded Voltage bus (4160 kV) to relay input voltage conversion factor is (35 *'.3) (References ESK-08ENS0 1, ESK-08EGS09, ESK-08EGS 10, G 13.18.6.2-ENS*002 and G 13.18.6.2-ENS*006).7.4.Output Documents (Any Changes to the data, analyses, or conclusions of calculation G13.18.3.1-004 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-302-1600, ENS-SWG1A Loss of Voltage Channel Calibration and Logic System Functional Test.7.4.2.2 STP-302-1601, ENS-SWG1B Loss of Voltage Channel Calibration and Logic System Functional Test.7.4.2.3 STP-302-1602, ENS-SWGIA Degraded Voltage Channel Calibration and Logic System Functional Test.7.4.2.4 STP-302-1603, ENS-SWG IB Degraded Voltage Channel Calibration and Logic System 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 setpoiot 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 G13.18.3.1-004 ENGINEERING DEPARTMENT Rev. 0 RIVER BEND STATION PAGE 7 OF 12 ENTERGY 8.0 Assumptions 8.1. The Limiting Operating Transient Variation (XT) is assumed to be equal to the minimum voltage observed during a LOCA transient at the Lower Analytical Limit for the Degraded Voltage Relays (See calculation G 13.18.3.6*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 3318.27 VAC (Section 7.2). Therefore, XT = 3318.27 /(35 x 4I3) = 54.73 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*002 and G13.18.6.2-ENS*006 (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: 7224.300-000-001B).
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 SETPOINT CALCULATION G13.18.3.1-004 ENGINEERING DEPARTMENT Rev. 0 RIVER BEND STATION PAGE8 OF 12 ENTERGY 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.Upper NTSP2 < Upper AL -+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*002 and G 13.18.6.2-ENS*006 EC-27437) using the methodologies provided in EN-IC-S-007-R and 7224.300-000-00 1B.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 52.55 s.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 = 3.22 x New Setpoint/Current Setpoint LU = 3.22 x 52.55/57.8
= 2.93 s TLU = 3.795 x 52.55/57.8
= 3.450 s AV MAX < Upper AL -I +LU I = 60 -2.93 = 57.07 s AV MIN > (NTSP2 -(AV MAX -NTSP2)) x 0.97 = (52.55 -(57.07 -52.55)) x 0.97 = 46.59 s NTSP2 (TRM) < Upper AL -I +TLU -LER Avoidance Margin = 60 -3.450 -4 = 52.55 s STP MIN = NTSP2 -ICTLI = 52.55 -3 =49.55 s STP MAX = NTSP2 + CTL = 52.55 + 3 = 55.55 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 51.23 VAC.
SETPOINT CALCULATION G13.18.3.1-004 ENGINEERING DEPARTMENT Rev. 0__RIVER BEND STATION PAGE 9 OF 12 ENTERGY Following calculations below provide the calculated STP, Allowable Value and Nominal Trip Setpoints (NTSP2). A margin of 1.5 V is used for LER Avoidance.
LU = 0.8675x New Setpoint/Current Setpoint LU = 0.8675 x 51.23/49 = 0.9067 VAC TLU = 1.019 x 51.23/49 = 1.07 VAC AV MIN > Lower AL + I +LU I 2950 / (35 x 43) + 0.9067 = 48.66 + 0.9067 = 49.57 VAC (rounded up)AV MAX < (NTSP2 + (NTSP2 -AV MIN)) x 1.03 = (51.23 + (51.23 -49.57)) x 1.03 = 54.48 VAC NTSP2 (TRM) > Lower AL + I +TLU I + LER Avoidance Margin = 48.66 + 1.07 + 1.5 = 51.23 VAC STP MIN = NTSP2 -ICTLj = 51.23 -0.87 = 50.36 VAC STP MAX = NTSP2 + ICTLI = 51.23 + 0.87 = 52.1 VAC 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-XTl
'= 2+ (+ )2 Where:.NTSP2 = Calculated Nominal Trip Setpoint, Upper XT = Limiting operating transient CrM = standard deviation for the operating transient (equal to zero when the limiting operating transient is based on documented operating conditions).
=0 C'/= standard deviation of the NTSP2 SETPOINT CALCULATION G13.18.3.1-004 ENGINEERING DEPARTMENT Rev. 0 RIVER BEND STATION PAGE10OF12 ENTERGY)2 +(CL)2 +(DL)2 +(P)2 +(E)2 The Total Loop Uncertainty is defined in EN-IC-S-007-R as: TLU= V(AL +(CLp (DL E)2 AL = Total random uncertainty that makes up the loop from device (provided in G1 3.18.2.3-ENS*002 and G1 3.18.2.3-ENS*006 EC-27437)AN = The loop from device uncertainty for normal conditions (i.e. AL determined for normal conditions)
SAL > AN Since, a higher value of or, reduces the spurious trip avoidance probability, therefore, it is conservative to assume that AN = AL for the equation for standard deviation.
o't \ )2 )2 2 2(= ~TL~J K (AL) +(CL) +(DL) -(A.) (E)2 Since, TLUas provided in G13.18.6.2-ENS*002 and G13.18.6.2-ENS*002, contains the same random component, -j)V(AL)2
+(CL)2 +(DL)2 +(pM )2 +(PE)2 ,for both positive and negative direction, a, = +TLU/m in = 1.645 (for Loss of Voltage relay)= 2 (for Degraded Voltage Relay No-LOCA time delay)a = 1.07 / 1.645 V= 0.650 V (for Loss of Voltage Relay)-3.45 / 2 s-1.725 s (for Degraded Voltage Relay No-LOCA time delay; used in Section 10.3.2.1)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.
SETPOINT CALCULATION G13.18.3.1-004 ENGINEERING DEPARTMENT Rev. 0 RIVER BEND STATION PAGE 11 OF 12 ENTERGY 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= 51.23 (Per Section 10.2)XT = Limiting operating transient= 54.73 V (Per Assumption 8.1.1)UAI = standard deviation for the operating transient (equal to zero when the limiting operating transient is based on documented operating conditions).
=0+TLU/ m in7 = 1:645=1.07 / 1.645 V= 0.650 V Spurious Trip Calculation:
Z- = 151.23-54.731
((0)2 + (0.650)2)1/2
= 5.38 The calculated value for ZT is greater than the required 1.645. Therefore the calculated.Nominal Trip Setpoint is acceptable.
SETPOINT CALCULATION G13.18.3.1-004 ENGINEERING DEPARTMENT Rev. 1 EN Y __RIVER BEND STATION Rev.0~PAGE 12 OF 12 ENTERGY 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 -A V- NTSP21 0"I Where: AV= Allowable Value NTSP2 = Calculated Nominal Trip Setpoint (7I = standard deviation of the NTSP 10.3.2.1 Degraded Voltage Relay No-LOCA time delay relay ZLER = 157.07- 52.55[1.725-2.62 10.3.2.2 Loss of Voltage relay ZLER 149.57-51.231 0.65= 2.56 The LER Avoidance values are equal to or above 1.28. The calculated values for ZLER (upper and lower) are deemed acceptable and demonstrate sufficient probability for LER avoidance.