ML050820561
ML050820561 | |
Person / Time | |
---|---|
Site: | Peach Bottom ![]() |
Issue date: | 03/21/2005 |
From: | NRC/NRR/DLPM |
To: | |
References | |
TAC MC2219, TAC MC2220 | |
Download: ML050820561 (74) | |
Text
iI r RPS Instrumentation 3.3.1.1 3.3 INSTRUMENTATION 3.3.1.1 Reactor Protection System (RPS) Instrumentation LCO 3.3.1.1 The RPS instrumentation for each Function in Table 3.3.1.1-1 shall be OPERABLE.
APPLICABILITY: According to Table 3.3.1.1-1.
ACTIONS
..----------------- NOTE-----------------------------------
Separate Condition entry is allowed for each channel.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or more required A.1 Place channel in 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> channels inoperable. trip.
.OR A.2 -------- NOTE--------- 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> Not applicable for Functions 2.a, 2.b, 2.c, 2.d, or 2.f. I Place associated trip system in trip.
B. -------- NOTE--------- 8.1 Place channel in one 6 hours0.25 days <br />0.0357 weeks <br />0.00822 months <br /> Not applicable for trip system in trip.
Functions 2.a, 2.bi 2.c, 2.d, or 2.f. I One or more Functions B.2 Place one trip system 6 hours0.25 days <br />0.0357 weeks <br />0.00822 months <br /> with one or more in trip.
required channels inoperable in both trip systems.
(continued)
PBAPS UNIT 2 3 .3-1 Amendment No. 251
e RPS Instrumentation 3.3.1.1 ACTIONS (continued)Y CONDITION REQUIRED ACTION - COMPLETION TIME H. As required by H.1 Initiate action to Immediately Required Action D.1 fully insert all and referenced in insertable control Table 3.3.1.1-1. rods in core cells containing one or more fuel assemblies.
I. As required by I.1 Initiate alternate 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> Required Action D.1 method to detect and and referenced in suppress thermal Table 3.3.1.1-1. hydraulic instability oscillations.
1.2 -------- NOTE--------
LCO 3.0.4 is not applicable.
Restore required 120 days channels to OPERABLE.
J. Required Action and J.1 Reduce THERMAL POWER 4 hours0.167 days <br />0.0238 weeks <br />0.00548 months <br /> associated Completion to <25% RTP.
Time of Condition I not met.
PBAPS UNIT 2 3.3-3 Amendment No. 10, 251
RPS Instrumentation 3.3.1.1 SURVEILLANCE REQUIREMENTS
- -------------- NOTES------------------------------------
- 1. Refer to Table 3.3.1.1-1 to determine which SRs apply for each RPS Function.
- 2. When a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours0.25 days <br />0.0357 weeks <br />0.00822 months <br /> provided the associated Function maintains RPS trip capability.
SURVEILLANCE FREQUENCY SR 3.3.1.1.1 Perform CHANNEL CHECK. 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> SR 3.3.1.1.2 ------------------ NOTE-------------------
Not required to be performed until 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> after THERMAL POWER . 25X RTP.
Verify the absolute difference between 7 days the average power range monitor (APRM) channels and the calculated power is s 2X RTP while operating at : 25X RTP.
(continued)
PBAPS UNIT 2 3.3-3a Amendment No.2+0, 251
RPS Instrumentation 3.3.1.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.1.1.9 Perform CHANNEL FUNCTIONAL TEST. 92 days SR 3.3.1.1.10 ------------ NOTE-------------------
Radiation detectors are excluded.
Perform CHANNEL CALIBRATION. 92 days SR 3.3.1.1.11 ------------------ NOTES------------------
- 1. For Function 2.a, not required to be performed when entering MODE 2 from MODE 1 until 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> after entering MODE 2.
- 2. For Functions 2.b and 2.f, the CHANNEL FUNCTIONAL TEST includes the recirculation flow input processing, excluding the flow transmitters.
Perform CHANNEL FUNCTIONAL TEST. 184 days SR 3.3.1.1.12 ------------------ NOTES------------------
- 1. Neutron detectors are excluded.
- 2. For Function 1, not required to be performed when entering MODE 2 from MODE 1 until 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> after entering MODE 2.
- 3. For Functions 2.b and 2.f, the recirculation flow transmitters that feed the APRMs are included.
Perform CHANNEL CALIBRATION. 24 months (continued)
PBAPS UNIT 2 3.3-5 Amendment No. £19, 216, 219, 222, 232, 251
f e RPS Instrumentation 3.3.1.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.1.1.13 Verify Turbine Stop Valve-Closure and 24 months Turbine Control Valve Fast Closure, Trip Oil Pressure-Low Functions are not bypassed when THERMAL POWER is 2 29.5% RTP.
SR 3.3.1.1.14 Perform CHANNEL FUNCTIONAL TEST. 24 months SR 3.3.1.1.15 Perform CHANNEL CALIBRATION. 24 months SR 3.3.1.1.16 Calibrate each radiation detector. 24 months SR 3.3.1.1.17 Perform LOGIC SYSTEM FUNCTIONAL TEST. 24 months SR 3.3.1.1.18 Verify the RPS RESPONSE TIME is within 24 months limits.
SR 3.3.1.1.19 Verify OPRM is not bypassed when APRM 24 months Simulated Thermal Power is 229.5X and recirculation drive flow is <60%.
PBAPS UNIT 2 3.3-6 Amendment No. 232, 247,
I-RPS Instrumentation 3.3.1.1 Table 3.3.1.1-1 (page 1 of 3)
Reactor Protection System Instrumentation APPLICABLE CONDITIONS PODES OR REQUIRED REFERENCED OTHER CHANNELS FROM SPECIFIED PER TRIP REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS SYSTEM ACTION D.1 RECUIREHENTS VALUE
- 1. Wtde Range Neutron Monitors
- a. Period-Short 2 3 G SR 3.3.1.1.1 213 seconds SR 3.3.1.1.5 SR 3.3.1.1.12 SR 3.3.1.1.17 SR 3.3.1.1.28 SWa) 3 H SR 3.3.1.1.1 2 13 seconds SR 3.3.1.1.6 SR 3.3.1.1.12 SR 3.3.1.1.17 SR 3.3.1.1.18
- b. Inop 2 3 G SR 3.3.1.1.5 NA SR 3.3.1.1.17 5 (a) 3 H SR 3.3.1.1.6 NA SR 3.3.1.1.17
- 2. Average Power Range Monitors
- a. Neutron Flux-High 2 3 (c) G SR 3.3.1.1.1 5.0S RTP 1s (Setdown) SR 3.3.1.1.8 SR 3.3.1.1.11 SR 3.3.1.1.12
- b. Simulated Thermal 1 3 (c) F SR 3.3.1.1.1 s 0.65 W Pover-Hi gh SR 3.3.1.1.2 4 63.7S RTP(b) and s 118.01 RTP SR 3.3.1.1.8 SR 3.3.1.1.11 SR 3.3.1.1.12
- c. Neutron Flux-High 1 3 F SR 3.3.1.1.1 S 119.75 RTP SR 3.3.1.1.2 SR 3.3.1.1.8 SR 3.3.1.1.11 SR 3.3.1.1.12
- d. Inop 1 2 3(c) G SR 3.3.1.1.11 NA
- e. 2-Out-Of-4 Voter 1.2 2 G SR 3.3.1.1.1 NA SR 3.3.1.1.11 SR 3.3.1.1.17 SR 3.3.1.1.18
- f. OPR.M Upscale Z25S 3 (c) I .SR 3.3.1.1.1 RTP SR 3 .3.12.1.8 SR 3.3 .12.1.11 SR 3.3 .1.1 .12 SR 3.3.1.1.19 (continued)
(a) With any control rod withdrawn from a core cell containing one or more fuel assemblies.
(b) 0.65 (v - AW) + 63.71 RtP vhen reset for single loop operation per LCO 3.4.1. Recirculation Loops Operating. I (c) Each APRM channel provides Inputs to both trip systems.
(d) See COLR for OPRlt period based detection algorithm (PBDA) setpoint limits.
PBAPS UNIT 2 3.3-7 Amendment No. 232, 24-7, 251
Recirculation Loops Operating 3.4.1 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.1 Recirculation Loops Operating LCO 3.4.1 Two recirculation loops with matched flows shall be in operation. I One recirculation loop shall be in operation with the I following limits applied when the associated LCO is applicable:
- a. LCO 3.2.1, "AVERAGE PLANAR LINEAR HEAT GENERATION RATE (APLHGR)," single loop operation limits specified in the I COLR;
- b. LCO 3.2.2, -MINIMUM CRITICAL POWER RATIO (MCPR)," single loop operation limits specified in the COLR; and
Instrumentation," Function 2.b (Average Power Range Monitors Simulated Thermal Power-High), Allowable Value of Table 3.3.1.1-1 is reset for single loop operation.
NOTE----------------------------
Required limit modifications for single recirculation loop operation may be delayed for up to 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> after transition from two recirculation loop operation to single recirculation loop operation.
APPLICABILITY: MODES 1 and 2.
PBAPS UNIT 2 3.4-1 Amendment No. 2+e, 232, 251
I r Recirculation Loops Operating 3.4.1 ACTIONS THIS PAGE LEFT BLANK INTENTIONALLY (The contents of this page have been deleted)
PBAPS UNIT 2 3.4-2 Amendment No. 2i.,
251
t I Recirculation Loops Operating 3.4.1 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME I
A. Requirements of the A.1 Satisfy the 24 hours1 days <br />0.143 weeks <br />0.0329 months <br /> LCO not met. requirements of the LCO.
B. No recirculation B.1 Be in MODE 3. 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> loops in operation.
DR Required Action and associated Completion Time of Condition A not met.
I PBAPS UNIT 2 3.4-3 Amendment No. 2+e, 251
Recirculation Loops Operating 3.4.1 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY
+
SR 3.4.1.1 ---------------------NOTE-------------------
Not required to be performed until 24 hours1 days <br />0.143 weeks <br />0.0329 months <br /> after both recirculation loops are in operation.
Verify recirculation loop jet pump flow 24 hours1 days <br />0.143 weeks <br />0.0329 months <br /> mismatch with both recirculation loops in operation is:
- a. < 10.25 X 106 lbm/hr when operating at
< 71.75 X 106 lbm/hr; and
- b. s 5.125 X 106 lbm/hr when operating at 2 71.75 X 10' ibm/hr.
PBAPS UNIT 2 3.4-4 Amendment No. 2£9, 251
Recirculation Loops Operating 3.4.1 I
THIS PAGE LEFT BLANK INTENTIONALLY (The contents of this page have been deleted)
PBAPS UNIT 2 3.4-5 Amendment No.2-0, 247, 251
I r RPS Instrumentation B 3.3.1.1 BASES APPLICABLE I.b. Wide Range Neutron Monitor-Inop (continued)
SAFETY ANALYSES, LCO, and Six channels of the Wide Range Neutron Monitor-mnop APPLICABILITY Function, with three channels in each trip system, are required to be OPERABLE to ensure that no single instrument failure will preclude a scram from this Function on a valid signal. Since this Function is not assumed in the safety analysis, there is no Allowable Value for this Function.
This Function is required to be OPERABLE when the Wide Range Neutron Monitor Period-Short Function is required.
Average Power Range Monitor (APRM)
The APRM channels provide the primary indication of neutron flux within the core and respond almost instantaneously to neutron flux increases. The APRM channels receive input signals from the local power range monitors (LPRMs) within the reactor core to provide an indication of the power distribution and local power changes. The APRM channels average these LPRM signals to provide a continuous indication of average reactor power from a few percent to greater than RTP. Each APRM also includes an Oscillation Power Range Monitor (OPRM) Upscale Function which monitors small groups of LPRM signals to detect thermal-hydraulic instabilities.
The APRM System is divided into four APRM channels and four 2-out-of-4 voter channels. Each APRM channel provides inputs to each of the four voter channels. The four voter channels are divided into two groups of two each, with each group of two providing inputs to one RPS trip system. The system is designed to allow one APRM channel, but no voter channels to be bypassed. A trip from any one unbypassed APRM wili result in a "half-trip" in all four of the voter channels, but no trip inputs to either RPS trip system.
APRM trip Functions 2.a, 2.b, 2.c, and 2.d are voted independently from OPRM Upscale Function 2.f. Therefore, any Function 2.a, 2.b, 2.c, or 2.d trip from any two unbypassed APRM channels will result in a full trip in each of the four voter channels, which in turn results in two trip inputs into each RPS trip system logic channel (Al, A2, B, and B2), thus resulting in a full scram signal.
Similarly, a Function 2.f trip from any two unbypassed APRM channels will result in a full trip from each of the four voter channels. Three of the four APRM channels and all four of the voter channels are required to be OPERABLE to ensure that no single failure will preclude a scram on a valid signal. In addition, to provide adequate coverage of the entire core consistent with the design bases for the APRM Functions L.a, 2.b, and 2.c, at least 20 LPRM inputs, with at least three LPRM inputs from each of the four axial levels at which the LPRMs are located, must be operable for each APRM channel, and the number of LPRM inputs that have become inoperable (and bypassed) since the last APRM calibration (SR 3.3.1.1.2) must be less than ten for each APRM channel. For the OPRM Upscale, Function 2.f, LPRMs are assigned to "cells" of 3 or 4 detectors. A minimum of 25 cells, each with a minimum of 2 OPERABLE LPRMs, must be OPERABLE for the OPRM Upscale Function 2.f to be OPERABLE.
(continued).
PBAPS UNIT 2 B 3.3-7 Revision No. ' .
RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.a. Average Power Range Monitor Neutron Flux-High SAFETY ANALYSES, £Setdown) (continued)
LCO, and APPLICABILITY For operation at low power (i.e., MODE 2), the Average Power Range Monitor Neutron Flux-High (Setdown)Function is capable of generating a trip signal that prevents fuel damage resulting from abnormal operating transients in this power range. For most operation at low power levels, the Avera9e Power Range Monitor Neutron Flux-High (Setdown)
Function will provide a secondary scram to the Wide Range Neutron Monitor Period-Short Function because of the relative setpoints. At higher power levels, it is possible that the Average Power Range Monitor Neutron Flux-High (Setdown) Function will provide the primary trip signal for a corewide increase in power.
No specific safety analyses take direct credit for the Average Power Range Monitor Neutron Flux-High (Setdown)
Function. However, this Function indirectly ensures that before the reactor mode switch is placed in the run position, reactor power does not exceed 25X RTP (SL 2.1.1.1) when operating at low reactor pressure and low core flow.
Therefore, it indirectly prevents fuel damage during significant reactivity increases with THERMAL POWER
< 25X RTP.
The Allowable Value is based on preventing si nificant increases in power when THERMAL POWER is < 25? RTP.
The Average Power Range Monitor Neutron Flux-High (Setdown)
Function must be OPERABLE during MODE 2 when control rods may be withdrawn since the potential for criticality exists.
In MODE 1, the Average Power Range Monitor Neutron Flux-High Function provides protection against reactivity transients and the RWM and rod block monitor protect against control rod withdrawal error events.
2.b. Average Power Range Monitor Simulated Thermal Power-High The Average Power Range Monitor Simulated Thermal Power-High Function monitors average neutron flux to approximate the THERMAL POWER being transferred to the reactor coolant. The APRM neutron flux is electronically filtered with a time constant representative of the fuel heat transfer dynamics to generate a signal proportional to the THERMAL POWER in the reactor. The trip level is varied as a function of recirculation drive flow (i.e., at lower core flows, the setpoint is reduced proportional to the reduction in power experienced as core flow is reduced with a fixed control rod pattern) but is clamped at an upper limit that is always lower than the Average Power Range Monitor Neutron Flux-High Function Allowable Value. A note is included, applicable when the plant is in single recirculation loop operation per LCO 3.4.1, which requires the flow value, used in the Allowable Value equation, be reduced by AlW. The value of AW (continued)
PBAPS UNIT 2 B 3.3-8 Revision No.
4 I RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.b. Average Power Rancie Monitor Simulated Thermal SAFETY ANALYSES, Power-High (continued)
LCO, and APPLICABILITY is established to conservatively bound the inaccuracy created in the core flow/drive flow correlation due to back flow in the jet pumps associated with the inactive recirculation loop. The Allowable Value thus maintains thermal margins essentially unchanged from those for two loop operation. The value of AW is plant specific and is defined in plant procedures. The Allowable Value equation for single loop operation is only valid for flows down to W = AW; the Allowable Value does not go below 63.7X RTP. This is acceptable because back flow in the inactive recirculation loop is only evident with drive flows of approximately 35Z or greater (Reference 19).
The Average Power Range Monitor Simulated Thermal Power-High Function is not specifically credited in the safety analysis but is intended to provide an additional margin of protection from transient induced fuel damage during operation where recirculation flow is reduced to below the minimum required for rated power operation. The Average Power Range Monitor Simulated Thermal Power-High Function provides protection against transients where THERMAL POWER increases slowly (such as the loss of feedwater heating event) and protects the fuel cladding integrity by ensuring that the MCPR SL is not exceeded. During these events, the THERMAL POWER increase does not significantly lag the neutron flux scram. For rapid neutron flux increase events, the THERMAL POWER lags the neutron flux and the Average Power Range Monitor Neutron Flux-High Function will provide a scram signal before the Average Power Range Monitor Simulated Thermal Power-High Function setpoint is exceeded.
Each APRM channel uses one total drive flow signal representative of total core flow. The total drive flow signal is generated by the flow processing logic, part of the APRM channel, by summing up the flow calculated from two flow transmitter signal inputs, one from each of the two recirculation loop flows. The flow processing logic OPERABILITY is part of the APRM channel OPERABILITY requirements for this Function. The APRM flow processing logic is considered inoperable whenever it cannot deliver a flow signal less than or equal to actual Recirculation flow conditions for all steady state and transient reactor conditions while in Mode 1. Reduced or'Downscale flow conditions due to planned maintenance or testing activities during derated Plant conditions (i.e. end of cycle coast down) will result in conservative setpoints for the APRM Simulated Thermal Power-High function, thus maintaining that function operable.
(continued)
PBAPS UNIT 2 B 3.3-9 Revision No.
RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.d. Average Power Range Monitor-Tnop SAFETY ANALYSES, LCO, and Three of the four APRM channels are required to be OPERABLE APPLICABILITY for each of the APRM Functions. This Function (Inop)
(continued) provides assurance that the minimum number of APRM channels are OPERABLE.
For any APRM channel, any time its mode switch is not in the "Operate" position, an APRM module required to issue a trip is unplugged, or the automatic self-test system detects a critical fault with the APRM channel, an Inop trip is sent to all four voter channels. Inop trip sfrom two or more unbypassed APRM channels result in a trip output from each of the four voter channels to it's associated trip system.
This Function was not specifically credited in the accident analysis, but it is retained for the overall redundancy and diversity of the RPS as required by the NRC approved licensing basis.
There is no Allowable Value for this Function.
This Function is required to be OPERABLE in the MODES where the APRM Functions are required.
2.e. 2-Out-Of-4 Voter The 2-Out-Of-4 Voter Function provides the interface between the APRM Functions, including the OPRM Upscale Function, and the final RPS trip system logic. As such, it is required to be OPERABLE in the MODES where the APRM Functions are required and is necessary to support the safety analysis applicable to each of those Functions. Therefore, the 2-Out-Of-4 Voter Function needs to be OPERABLE in MODES 1 and 2.
All four voter channels are required to be OPERABLE. Each voter channel includes self-diagnostic functions. If any voter channel detects a critical fault in its own processing, a trip is issued from that voter channel to the associated trip system.
The 2-Out-Of-4 Logic Module includes 2-Out-Of-4 Voter hardware and the APRM Interface hardware. The 2-Out-Of-4 Voter Function 2.e votes APRM Functions 2.a, 2.b, 2.c and 2.d independently of Function 2.f. This voting is accomplished by the 2-Out-Of-4 Voter hardware in the 2-Out-Of-4 Logic Module.
Each 2-Out-Of-4 Voter includes two redundant sets of outputs to RPS. Each output set contains two independent contac s; one contact for Functions 2.a, 2.b 2.c and 2.d, and the other contact for Function 2.f. The analysis in Reference 12 took credit for this redundancy in the justification of the 12-hour Completion Time for Condition A, so the voter Function 2.e must be declared inoperable if any of its functionality is inoperable. However the voter Function 2.e does not need to be declared inoperable due to any failure affecting only the plant interface portions of the 2-Out-Of-4 Logic Module that are not necessary to perform the 2-Out-Of-4 Voter function.
There is no Allowable Value for this Function.
(continued)
PBAPS UNIT 2 B 3.3-12 Revision No.
1 RPS Instrumentation RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.f. Oscillation Power Ranne Monitor (OPRM) Upscale SAFETY ANALYSES, LCO, and The OPRM Upscale Function provides compliance with 10 CFR APPLICABILITY 50, Appendix A, General Design Criteria (GDC) 10 and 12, (continued) thereby providing protection from exceeding the fuel MCPR safety limit (SL) due to anticipated thermal-hydraulic power oscillations.
References 14, 15 and 16 describe three algorithms for detecting thermal-hydraulic instability related neutron flux oscillations: the period based detection algorithm (PBDA), the amplitude based algorithm (ABA), and the growth rate algorithm (GRA). All three are implemented in the OPRM Upscale Function, but the safety analysis takes credit only for the PBDA. The remaining algorithms provide defense in depth and additional protection against unanticipated oscillations. OPRM Upscale Function OPERABILITY for Technical Specifications purposes is based only on the PBDA.
The OPRM Upscale Function receives input signals from the local power range monitors (LPRMs) within the reactor core, which are combined into "cells' for evaluation by the OPRM algorithms. Each channel is capable of detecting thermal-hydraulic instabilities, by detecting the related neutron flux oscillations, and issuing a trip signal before the MCPR SL is exceeded. Three of the-four channels are required to be OPERABLE.
The OPRM Upscale trip is automatically enabled (bypass removed) when THERMAL POWER is 2 29.5% RTP, as indicated by the APRM Simulated Thermal Power, and reactor core flow is
< 60% of rated flow, as indicated by APRM measured recirculation drive flow. This is the operating region where actual thermal-hydraulic instability and related neutron flux oscillations may occur (Reference 18). These setpoints, which are sometimes referred to as the "auto-bypass" setpoints, establish the boundaries of the OPRM Upscale trip enabled region.
The OPRM Upscale Function is required to be OPERABLE when the plant is at 2 25% RTP. The 25% RTP level is selected to provide margin in the unlikely event that a reactor power increase transient occurring while the plant is operating below 29.5% RTP causes a power increase to or beyond the 29.5% APRM Simulated Thermal Power OPRM Upscale trip auto-enable setpoint without operator action. This OPERABILITY requirement assures that the OPRM Upscale trip auto-enable function will be OPERABLE when required.
(continued)
PBAPS UNIT 2 B 3.3-12a Revision No. '
RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.f. Oscillation Power Range Monitor (OPRM)
SAFETY ANALYSES, Upscale (continued)
LCO, and APPLICABILITY An OPRM Upscale trip is issued from an APRM channel when (continued) the PBDA in that channel detects oscillatory changes in the neutron flux, indicated by the combined signals of the LPRM detectors in a cell, with period confirmations and relative cell amplitude exceeding specified setpoints. One or more cells in a channel exceeding the trip conditions will result in a channel trip. An OPRM Upscale trip is also issued from the channel if either the GRA or ABA detects oscillatory changes in the neutron flux for one or more cells in that channel.
There are four "sets" of OPRM related setpoints or adjustment parameters: a) OPRM trip auto-enable setpoints for Simulated Thermal Power (29.5Z) and drive flow (60X); b)
PBDA confirmation count and amplitude setpoints; c) PBDA tuning parameters; and d) GRA and ABA setpoints.
The first set, the OPRM auto-enable region setpoints, as discussed in the SR 3.3.1.1.19 Bases, are treated as nominal setpoints without the application of setpoint methodology per Reference 18. The settings, 29.5X APRM Simulated Thermal Power and 60X drive flow, are defined (limit values) in and confirmed by SR 3.3.1.1.19. The second set, the OPRM PBDA trip setpoints, are established in accordance with methodologies defined in Reference 16, and are documented in the COLR. There are no Technical Specifications allowable values for these setpoints.
The third set, the OPRM PBDA "tuning" parameters, are established or adjusted in accordance with and controlled by PBAPS procedures. The fourth set, the GRA and ABA setpoints, in accordance with References 14, 15 and 16, are established as nominal values only, and controlled by PBAPS procedures.
(continued)
PBAPS UNIT 2 B 3.3-12b Revision No.
RPS Instrumentation B 3.3.1.1 BASES ACTIONS A.1 and A.2 (continued)
Function's inoperable channel is in one trip system and the Function still maintains RPS trip capability (refer to Required Actions B.1, B.2, and C.1 Bases). If the inoperable channel cannot be restored to OPERABLE status within the allowable out of service time, the channel or the associated trip system must be placed in the tripped condition per Required Actions A.1 and A.2. Placing the inoperable channel in trip (or the associated trip system in trip) would conservatively compensate for the inoperability, restore capability to accommodate a single failure, and allow operation to continue. Alternatively, if it is not desired to place the channel (or trip system) in trip (e.g.,
as in the case where placing the inoperable channel in trip would result in a full scram), Condition D must be entered and its Required Action taken.
As noted, Action A.2 is not applicable for APRM Functions 2.a, 2.b, 2.c, 2.d, or 2.f. Inoperability of one required APRM channel affects both trip systems. For that condition, Required Action A.1 must be satisfied, and is the only action (other than restoring operability) that will restore capability to accommodate a single failure. Inoperability of more than one required APRM channel of the same trip function results in loss of trip capability and entry into Condition C, as well as entry into Condition A for each channel.
B.1 and B.2 Condition B exists when, for any one or more Functions, at least one required channel is inoperable in each trip system. In this condition, provided at least one channel per trip system is OPERABLE, the RPS still maintains trip capability for that Function, but cannot accommodate a single failure in either trip system.
Required Actions B.1 and B.2 limit the time the RPS scram logic, for any Function, would not accommodate single failure in both trip systems (e.g., one-out-of-one and one-out-of-one arrangement for a typical four channel Function). The reduced reliability of this logic arrangement was not evaluated in References 9, 12 or 13 for the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion Time. Within the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowance, the associated Function will have all required channels OPERABLE or in trip (or any combination) in one trip system.
(continued)
PBAPS UNIT 2 B 3.3-24 Revision No.
4- I RPS Instrumentation B 3.3.1.1 BASES ACTIONS B.1 and-B.2 (continued)
Completing one of these Required Actions restores RPS to a reliability level equivalent to that evaluated in References 9, 12 or 13, which justified a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> allowable out of service time as presented in Condition A. The trip system in the more degraded state should be placed in trip or, alternatively, all the inoperable channels in that trip system should be placed in trip (e.g., a trip system with two inoperable channels could be in a more degraded state than a trip system with four inoperable channels if the two inoperable channels are in the same Function while the four inoperable channels are all in different Functions). The decision of which trip system is in the more degraded state should be based on prudent judgment and take into account current plant conditions (i.e., what MODE the plant is in).
If this action would result in a scram or RPT, it is permissible to place the other trip system or its inoperable channels in trip.
The 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Completion Time is judged acceptable based on the remaining capability to trip, the diversity of the sensors available to provide the trip signals, the low probability of extensive numbers of inoperabilities affecting all diverse Functions, and the low probability of an event requiring the initiation of a scram.
Alternately, if it is not desired to place the inoperable channels (or one trip system) in trip (e.g., as in the case where placing the inoperable channel or associated trip system in trip would result in a scram, Condition D must be entered and its Required Action taken.
As noted, Condition B is not applicable for APRM Functions 2.a, 2.b, 2.c, 2.d, or 2.f. Inoperability of an APRM channel affects both trip systems and is not associated with a specific trip system as are the APRM 2-Out-Of-4 voter and other non-APRM channels for which Condition B applies. For an inoperable APRM channel, Required Action A.1 must be, satisfied, and is the only action (other than restoring operability) that will restore capability to accommodate a single failure. Inoperability of a Function in more than one required APRM channel results in loss of trip capability for that Function and entry into Condition C, as well as entry into Condition A for each channel. Because Condition A and C provide Required Actions that are appropriate for the inoperability of APRM Functions 2.a, 2.b, 2.c, 2.d, or 2.f, and these functions are not associated with specific trip systems as are the APRM 2-Out-Of-4 voter and other non-APRM channels, Condition B does not apply.
(continued)
PBAPS UNIT 2 B 3.3-25 Revision No.
RPS Instrumentation B 3.3.1.1 BASES ,
ACTIONS E.1. F.1. G.1. and J.1 (continued)
If the channel(s) is not restored to OPERABLE status or placed in trip (or the associated trip system placed in trip) within the allowed Completion Time, the plant must be placed in a MODE or other specified condition in which the LCO does not apply. The allowed Completion Times are reasonable, based on operating experience, to reach the specified condition from full power conditions in an orderly manner and without challenging plant systems. In addition, the Completion.Time of Required Actions E.1 and J.1 are consistent with the Completion Time provided in LCO 3.2.2, "MINIMUM CRITICAL POWER RATIO (MCPR)."
If the channel(s) is not restored to OPERABLE status or placed in trip (or the associated trip system placed in trip) within the allowed Completion Time, the plant must be placed in a MODE or other specified condition in which the LCO does not apply. This is done by immediately initiating action to fully insert all insertable control rods in core cells containing one or more fuel assemblies. Control rods in core cells containing no fuel assemblies do not affect the reactivity of the core and are, therefore, not required to be inserted. Action must continue until all insertable control rods in core cells containing one or more fuel assemblies are fully inserted.
If OPRM Upscale trip capability is not maintained, Condition I exists. References 12 and 13 justified use of alternate methods to detect and suppress oscillations for a limited period of time. The alternate methods are procedurally established consistent with the guidelines identified in Reference 17 requiring manual operator action to scram the plant if certain predefined events occur. The 12-hour allowed Completion Time for Required Action 1.1 is based on engineering judgment to allow orderly transition to the alternate methods while limiting the period of time during which no automatic or alternate detect and suppress trip capability is formally in place. Based on the small probability of an instability event occurring at all, the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> duration is judged to be reasonable.
(continued)
PBAPS UNIT 2 B 3.3-27 Revision No. Ad
4- e RPS Instrumentation B 3.3.1.1 BASES -
ACTIONS I (continued)
The alternate method to detect and suppress oscillations implemented in accordance with 1.1 was evaluated (References 12 and 13) based on use up to 120 days only. The evaluation, based on engineering judgment, concluded that the likelihood of an instability event that could not be adequately handled by the alternate methods during this 120-day period was negligibly small. The 120-day period is intended to be an outside limit to allow for the case where design changes or extensive analysis might be required to understand or correct some unanticipated characteristic of the instability detection algorithms or equipment. This action is not intended and was not evaluated as a routine alternative to returning failed or inoperable equipment to OPERABLE status.
Correction of routine equipment failure or inoperability is expected to normally be accomplished within the completion times allowed for Actions for Condition A.
A note is provided to indicate that LCO 3.0.4 is not applicable. The intent of that note is to allow plant startup while operating within the 120-day completion time for action 1.2. The primary purpose of this exclusion is to allow an orderly completion of design and verification activities, in the event of a required design change, without undue impact on plant operation.
SURVEILLANCE As noted at the beginning of the SRs, the SRs for each RPS REQUIREMENTS instrumentation Function are located in the SRs column of Table 3.3.1.1-1.
The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours0.25 days <br />0.0357 weeks <br />0.00822 months <br />, provided the associated Function maintains RPS trip capability. Upon completion of the Surveillance, or expiration of the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the reliability analysis (Refs. 9, 12 & 13) assumption of the average time required to perform channel Surveillance.
That analysis demonstrated that the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> testing allowance does not significantly reduce the probability that the RPS will trip when necessary.
(continued)
PBAPS UNIT 2 B 3.3-27a Revision No..
I I RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.9 and SR 3.3.1.1.14 (continued)
REQUI REM ENTS In addition, Function 5 and 7 instruments are not accessible while the unit is operating at power due to high radiation and the installed indication instrumentation does not provide accurate indication of the trip setting. For the Function 9 channels, verification that the trip settings are less than or equal to the specified Allowable Value during the CHANNEL FUNCTIONAL TEST is not required since the instruments are not accessible while the unit is operating at power due to high radiation and the installed indication instrumentation does not provided accurate indication of the trip setting. Waiver of these verifications for the above functions is considered acceptable since the magnitude of drift assumed in the setpoint calculation is based on a 24 month calibration interval. The 92 day Frequency of SR 3.3.1.1.9 is based on the reliability analysis of Reference 9.
The 24 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power.
Operating experience has shown that these components will ass the Surveillance when performed at the 24 month Frequency.
SR 3.3.1.1.10. SR 3.3.1.1.12. SR 3.3.1.1.15.
and SR 3.3.1.1.16 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies that the channel responds to the measured parameter within the necessary range and accuracy. CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations, consistent with the current plant specific setpoint methodology.
As noted for SR 3.3.1.1.10 radiation detectors are excluded from CHANNEL CALIBRATION due to ALARA reasons (when the plant is operating, the radiation detectors are generally in a high radiation area; the steam tunnel). This exclusion is acceptable because the radiation detectors are passive devices, with minimal drift. To complete the radiation CHANNEL CALIBRATION, SR 3.3.1.1.16 requires that the radiation detectors be calibrated on a once per 24 months Frequency.
The once per 92 days Frequency of SR 3.3.1.1.10 is conservative with respect to the magnitude of equipment drift assumed in the setpoint analysis. The Frequency of SR 3.3.1.1.16 is based upon the assumption of a 24-month calibration interval used in the determination of the equipment drift in the setpoint analysis.
As noted for SR 3.3.1.1.12, neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devices, with minimal drift, and because of the difficulty of simulating a meaningful signal. Changes in (continued)
PBAPS UNIT 2 B 3.3-32 Revision No.
RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.10. SR 3.3.1.1.12. SR 3.3.1.1.15.
REQUIREMENTS and SR 3.3.1.1.16 (continued) neutron detector sensitivity are compensated for by performing the 7 day calorimetric calibration (SR 3.3.1.1.2) and the 1000 MWD/T LPRM calibration against the TIPs (SR 3.3.1.1.8).
A second note is provided for SR 3.3.1.1.12 that allows the WRNM SR to be performed within 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> of entering MODE 2 from MODE 1. Testing of the MODE 2 WRNM Functions cannot be performed in MODE 1 without utilizing jumpers, lifted leads or movable links. This Note allows entry into MODE 2 from MODE 1, if the 24 month Frequency is not met per SR 3.0.2.
Twelve hours is based on operating experience and in consideration of providing a reasonable time in which to complete the SR.
A third note is provided for SR 3.3.1.1.12 that includes in the SR the recirculation flow (drive flow) transmitters, which supply the flow signal to the APRMs. The APRM Simulated Thermal Power-High Function (Function 2.b) and the OPRM Upscale Function (Function 2.f), both require a valid drive flow signal. The APRM Simulated Thermal Power-High Function uses drive flow to vary the trip setpoint. The OPRM Upscale Function uses drive flow to automatically enable or bypass the OPRM Upscale trip output to RPS. A CHANNEL CALIBRATION of the APRM drive flow signal requires both calibrating the drive flow transmitters and establishing a valid drive-flow /
core flow relationship. The drive flow /core flow relationship is established once per refuel cycle, while operating at or near rated power and flow conditions. This method of correlating core flow and drive flow is consistent with GE recommendations. Changes throughout the cycle in the drive flow / core flow relationship due to the changing thermal hydraulic operating conditions of the core are accounted for in the margins included in the bases or analyses used to establish the setpoints for the APRM Simulated Thermal Power-High Function and the OPRM Upscale Function.
The Frequencies of SR 3.3.1.1.12 and SR 3.3.1.1.15 are based upon the assumption of a 24-month calibration interval used in the determination of the equipment drift in the setpoint analysis.
SR 3.3.1.1.11 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the (continued)
PBAPS UNIT 2 B 3.3-33 Revision No.
RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.11 (continued)
REQUIREMENTS intended function. For the APRM Functions, this test supplements the automatic self-test functions that operate continuously in the APRM and voter channels. The scope of the APRM CHANNEL FUNCTIONAL TEST is limited to verification of system trip output hardware. Software controlled functions are tested only incidentally. Automatic internal self-test functions check the EPROMs in which the software-controlled logic is defined. Any changes in the EPROMs will be detected by the self-test function resulting in a trip and/or alarm condition. The APRM CHANNEL FUNCTIONAL TEST covers the APRM channels (including recirculation flow processing - applicable to Function 2.b and the auto-enable portion of Function 2.f only), the 2-Out-Of 4 voter channels, and the interface connections into the RPS trip systems from the voter channels. Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology. The 184 day Frequency of SR 3.3.1.1.11 is based on the reliability analyses of References 12 and 13. (NOTE: The actual voting logic of the 2-Out-Of-4 Voter Function is tested as part of SR 3.3.1.1.17. The actual auto-enable setloints for the OPRM Upscale trip are confirmed by SR 3.3.1. .19.)
A Note is provided for Function 2.a that requires' this SR to be performed within 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> of entering MODE 2 from MODE 1.
Testing of the MODE 2 APRM Function cannot be performed in MODE 1 without utilizing jumpers or lifted leads. This Note allows entry into MODE 2 from MODE 1 if the associated Frequency is not met per SR 3.0.2.
A second Note is provided for Function 2.b that clarifies that the CHANNEL FUNCTIONAL TEST for Function 2.b includes testing of the recirculation flow processing electronics, excluding the flow transmitters.
SR 3.3.1.1.13a This SR ensures that scrams initiated from the Turbine Stop Valve-Closure and Turbine Control Valve Fast Closure, Trip Oil Pressure-Low Functions will not be inadvertently bypassed when THERMAL POWER is k 29.5% RTP. This involves calibration of the bypass channels. Adequate margins for the instrument setpoint methodologies are incorporated into the Allowable Value (s 28.9% RTP which is equivalent to s 138.4 psig as measured from turbine first stage pressure) and the actual setpoint. Because main turbine bypass flow can affect this setpoint nonconservatively (THERMAL POWER is derived from turbine first stage pressure), the main turbine bypass valves must remain closed during the calibration at THERMAL POWER 2 29.5% RTP to ensure that the calibration is valid.
If any bypass channel's setpoint is nonconservative (i.e.,
the Functions are bypassed at 2 29.5% RTP, either due to open main turbine bypass valve(s) or other reasons), then the (continued)
PBAPS UNIT 2 B 3.3-34 Revision No. '
4 I RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.13 (continued)
REQUIREMENTS affected Turbine Stop Valve-Closure and Turbine Control Valve Fast Closure, Trip Oil Pressure-Low Functions are considered inoperable. Alternatively, the bypass channel can be placed in the conservative condition (nonbypass). If placed in the nonbypass condition, this SR is met and the channel is considered OPERABLE.
The Frequency of 24 months is based on engineering judgment and reliability of the components.
SR 3.3.1.1.17 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required trip logic for a specific channel. The functional testing of control rods (LCO 3.1.3), and SDV vent and drain valves (LCO 3.1.8),
overlaps this Surveillance to provide complete testing of the assumed safety function.
The 24 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power.
Operating experience has shown that these components will pass the Surveillance when performed at the 24 month Frequency.
The LOGIC SYSTEM FUNCTIONAL TEST for APRM Function 2.e simulates APRM and OPRM trip conditions at the 2-Out-Of-4 voter channel inputs to check all combinations of two tripped inputs to the 2-Out-Of-4 logic in the voter channels and APRM related redundant RPS relays.
SR 3.3.1.1.18 This SR ensures that the individual channel response times are maintained less than or equal to the original design value. The RPS RESPONSE TIME acceptance criterion is included in Reference 11.
RPS RESPONSE TIME tests are conducted on a 24 month Frequency. The 24 month Frequency is consistent with the PBAPS refueling cycle and is based upon plant operating experience, which shows that random failures of instrumentation components causing serious response time degradation, but not channel failure, are infrequent occurrences.
(continued)
PBAPS UNIT 2 B 3.3-35 Revision No.
I RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.19 REQUIREMENTS (continued) This surveillance involves confirming the OPRM Upscale trip auto-enable setpoints. The auto-enable setpoint values are considered to be nominal values as discussed in Reference 18.
This surveillance ensures that the OPRM Upscale trip is enabled (not bypassed) for the correct values of APRM Simulated Thermal Power and recirculation drive flow. Other surveillances ensure that the APRM Simulated Thermal Power and recirculation drive flow properly correlate with THERMAL POWER (SR 3.3.1.1.2) and core flow (SR 3.3.1.1.12),
respectively.
If any auto-enable setpoint is nonconservative (i.e., the OPRM Upscale trip is bypassed when APRM Simulated Thermal Power 229.5% and recirculation drive flow < 60X), then the affected channel is considered inoperable for the OPRM Upscale Function. Alternatively, the OPRM Upscale trip auto-enable setpoint(s) may be adjusted to place the channel in a conservative condition (not bypassed). If the OPRM Upscale trip is placed in the not-bypassed condition, this SR is met and the channel is considered OPERABLE.
The Frequency of 24 months is based on engineering judgment and reliability of the components.
REFERENCES 1. UFSAR, Section 7.2.
- 2. UFSAR, Chapter 14.
- 3. NEDO-32368, "Nuclear Measurement Analysis and Control Wide Range Neutron Monitoring System Licensing Report for Peach Bottom Atomic Power Station, Units 2 and 3,"
November 1994.
- 4. NEDC-32183P, "Power Rerate Safety Analysis Report for Peach Bottom 2 & 3," dated May 1993.
- 5. UFSAR, Section 14.6.2.
- 6. UFSAR, Section 14.5.4.
- 7. UFSAR, Section 14.5.1.
- 8. P. Check (NRC) letter to G. Lainas (NRC), "BWR Scram Discharge System Safety Evaluation," December 1, 1980.
- 9. NEDO-30851-P-A , "Technical Specification Improvement Analyses for BWR Reactor Protection System," March 1988.
(continued)
PBAPS UNIT-2 B 3.3-35a Revision No. "
4 I RPS Instrumentation B 3.3.1.1 BASES REFERENCES 10. MDE-87-0485-1, "Technical Specification Improvement (continued) Analysis for the Reactor Protection System for Peach Bottom Atomic Power Station Units 2 and 3," October 1987.
- 11. UFSAR, Section 7.2.3.9.
- 12. NEDC-32410P-A, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM)
Retrofit Plus Option III Stability Trip Function",
October 1995. I
- 13. NEDC-32410P Supplement 1, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function, Supplement 1", November 1997.
- 14. NEDO-31960-A, "BWR Owners' Group Long-Term Stability Solutions Licensing Methodology," November 1995.
- 15. NEDO-31960-A, Supplement 1, "BWR Owners' Group Long-Term Stability Solutions Licensing Methodology," November 1995.
- 16. NEDO-32465-A, "Reactor Stability Detect and Suppress Solutions Licensing Basis Methodology And Reload Applications," August 1996.
- 17. Letter, L. A. England (BWROG) to M. J. Virgilio, "BWR Owners' Group Guidelines for Stability Interim Corrective Action," June 6, 1994.
Phillips (NRC), "Guidelines for Stability Option III
'Enable Region' (TAC M92882)," September 17, 1996.
- 19. NEDO-24229-1, "Peach Bottom Atomic Power Station Units 2 and 3 Single-Loop Operation," May 1980.
PBAPS UNIT 2 B 3.3-35b Revision No.. X:l
Recirculation Loops Operating B 3.4.1 BASES APPLICABLE Plant specific LOCA and average power range monitor/rod SAFETY ANALYSES block monitor Technical Specification/maximum extended load (continued) line limit analyses have been performed assuming only one operating recirculation loop. These analyses demonstrate that, in the event of a LOCA caused by a pipe break in the operating recirculation loop, the Emergency Core Cooling System response will provide adequate core cooling (Refs. 2, 3, and 4).
The transient analyses of Chapter 14 of the UFSAR have also been performed for single recirculation loop operation (Ref. 5) and demonstrate sufficient flow coastdown characteristics to maintain fuel thermal margins during the abnormal operational transients analyzed provided the MCPR requirements are modified. During single recirculation loop operation, modification to the Reactor Protection System (RPS) average power range monitor (APRM) instrument setpoints is also required to account for the different relationships between recirculation drive flow and reactor core flow. The MCPR limits and APLHGR limits (power-dependent APLHGR multipliers, MAPFACp, and flow-dependent APLHGR multipliers, MAPFAC,) for single loop operation are specified in the COLR. The APRM Simulated Thermal Power-High Allowable Value is in LCO 3.3.1.1, 'Reactor Protection System (RPS) Instrumentation.'
(continued)
PBAPS UNIT 2 B 3.4-3 Revision No.
I Recirculation Loops Operating B 3.4.1 BASES APPLICABLE SAFETY ANALYSES (continued)
Recirculation loops operating satisfies Criterion 2 of the NRC Policy Statement.
LCO Two recirculation loops are normally required to be in operation with their flows matched within the limits specified in SR 3.4.1.1 to ensure that during a LOCA caused by a break of the piping of one recirculation loop the (conti nued)
PBAPS UNIT 2 B 3.4-4 Revision No. -
Recirculation Loops Operating B 3.4.1 BASES LCO (continued) assumptions of the LOCA analysis are satisfied. I Alternatively, with only one recirculation loop in operation, modifications to the required APLHGR limits (power- and flow-dependent APLHGR multipliers, MAPFAC, and MAPFAC,, respectively of LCO 3.2.1, "AVERAGE PLANAR LINEAR HEAT GENERATION RATE (APLHGR)"), MCPR limits (LCO 3.2.2, "MINIMUM CRITICAL POWER RATIO (MCPR)") and APRM Simulated Thermal Power-High Allowable Value (LCO 3.3.1.1) must be applied to allow continued operation consistent with the assumptions of.Reference 5. I The LCO is modified by a Note which allows up to 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> before having to put in effect the required modifications to required limits after a change in the reactor operating conditions from two recirculation loops operating to single recirculation loop operation. If the required limits are not in compliance with the applicable requirements at the end of this period, the associated equipment must be declared inoperable or the limits "not satisfied," and the ACTIONS required by nonconformance with the applicable specifications implemented. This time is provided due to the need to stabilize operation with one recirculation loop, including the procedural steps necessary to limit flow in the operating loop, and the complexity and detail required I to fully implement and confirm the required limit modifications.
APPLICABILITY In MODES 1 and 2, requirements for operation of the Reactor Coolant Recirculation System are necessary since there is considerable energy in the reactor core and the limiting design basis transients and accidents are assumed to occur.
In MODES 3, 4, and 5, the consequences of an accident are reduced and the coastdown characteristics of the recirculation loops are not important.
(continued)
PBAPS UNIT 2 B 3.4-5 Revision No.
Recirculation Loops Operating B 3.4.1 BASES THIS PAGE LEFT BLANK INTENTIONALLY (The contents of this page have been deleted)
PBAPS UNIT 2 B 3.4-6 Revision No.
4 r Recirculation Loops Operating B 3.4.1 BASES ACTIONS (continued)
With the requirements of the LCO not met, the recirculation I loops must be restored to operation with matched flows within 24 hours1 days <br />0.143 weeks <br />0.0329 months <br />. A recirculation loop is considered not in operation when the pump in that loop is idle or when the mismatch between total jet pump flows of the two loops is greater than required limits. The loop with the lower flow must be considered not in operation. Should a LOCA occur I with one recirculation loop not in operation, the core flow coastdown and resultant core response may not be bounded by the LOCA analyses. Therefore, only a limited time is allowed to restore the inoperable loop to operating status.
Alternatively, if the single loop requirements .of the LCO are applied to operating limits and RPS setpoints, operation with only one recirculation loop would satisfy the requirements of the LCO and the initial conditions of the accident sequence.
The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time is based on the low probability of an accident occurring during this time period, on a reasonable time to complete the Required Action, and on frequent core monitoring by operators allowing abrupt changes in core flow conditions to be quickly detected.
(continued)
PBAPS UNIT 2 B 3.4-7 Revision No.
Loops Operating Recirculation Recirculation Loops Operating B 3.4.1 BASES ACTIONS A1 (continued)
This Required Action does not require tripping the recirculation pump in the lowest flow loop when the mismatch between total jet pump flows of the two loops is greater than the required limits. However, in cases where large flow mismatches occur, low flow or reverse flow can occur in the low flow loop jet pumps, causing vibration of the jet pumps. If zero or reverse flow is detected, the condition should be alleviated by changing pump speeds to re-establish forward flow or by tripping the pump.
With no recirculation loops in operation or the Required Action and associated Completion Time of Condition A not met, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to MODE 3 within 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br />. In this condition, the recirculation loops are not required to be operating because of the reduced severity of DBAs and minimal dependence on the recirculation loop coastdown characteristics. The allowed Completion Time of 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> is reasonable, based on operating experience, to reach MODE 3 from full power conditions in an orderly manner and without challenging plant systems.
(continued)
PBAPS UNIT 2 B 3.4-8 Revision No. 5
ec L Recirculation Loops Operating B 3.4.1 BASES SURVEILLANCE SR 3.4.1.1 REQUIREMENTS This SR ensures the recirculation loops are within the allowable limits for mismatch. At low core flow (i.e.,
< 71.75 X 106 lbm/hr), the MCPR requirements provide larger margins to the fuel cladding integrity Safety Limit such that the potential adverse effect of early boiling transition during a LOCA is reduced. A larger flow mismatch can therefore be allowed when core flow is < 71.75 X 106 lbm/hr. The recirculation loop jet pump flow, as used in this Surveillance, is the summation of the flows from all of the jet pumps associated with a single recirculation loop.
The mismatch is measured in terms of core flow. (Rated core flow is 102.5 X 106 lbm/hr. The first limit is based on mismatch s 10% of rated core flow when operating at < 70% of rated core flow. The second limit is based on mismatch - 5%
of rated core flow when operating at > 70% of rated core flow.) If the flow mismatch exceeds the specified limits, the loop with the lower flow is considered not in operation.
The SR is not required when both loops are not in operation since the mismatch limits are meaningless during single loop or natural circulation operation. The Surveillance must be performed within 24 hours1 days <br />0.143 weeks <br />0.0329 months <br /> after both loops are in operation.
The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Frequency is consistent with the Surveillance Frequency for jet pump OPERABILITY verification and has been shown by operating experience to be adequate to detect off normal jet pump loop flows in a timely manner.
PBAPS UNIT 2 B 3.4-9 Revision No.
LopI prtn Recirclatio Recirculation Loops Operating B 3.4.1 BASES REFERENCES 1. UFSAR, Section 14.6.3.
- 2. NEDC-32163P, "PBAPS Units 2 and 3 SAFER/GESTR-LOCA Loss-of-Coolant Accident Analysis," January 1993.
- 3. NEDC-32162P, "Maximum Extended Load Line Limit and ARTS Improvement Program Analyses for Peach Bottom Atomic Power Station Unit 2 and 3," Revision 1, February 1993.
- 4. NEDC-32428P, "Peach Bottom Atomic Power Station Unit 2 Cycle 11 ARTS Thermal Limits Analyses," December 1994.
- 5. NEDO-24229-1, "PBAPS Units 2 and 3 Single-Loop Operation," May 1980.
- 6. NEDC-33064P, "Safety Analysis Report For Peach Bottom Atomic Power Station Units 2 & 3 Thermal Power Optimization," May 2002.
PBAPS UNIT 2 B 3.4-10 Revision No. a,
Reporting Requirements 5.6 5.6 Reporting Requirements (continued) 5.6.5 CORE OPERATING LIMITS REPORT (COLR)
- a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload cycle, and shall be documented in the COLR for the following:
- 1. The Average Planar Linear Heat Generation Rate for Specification 3.2.1;
- 2. The Minimum Critical Power Ratio for Specifications 3.2.2 and 3.3.2.1;
- 3. The Linear Heat Generation Rate for Specification 3.2.3;
- 4. The Control Rod Block Instrumentation for Specification 3.3.2.1; and
- 5. The Oscillation Power Range Monitor (OPRM)
Instrumentation for Specification 3.3.1.1.
- b. The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:
- 1. NEDE-24011-P-A, 'General Electric Standard Application for Reactor Fuel" (latest approved version as specified in the COLR);
- 2. NEDC-32162P, "Maximum Extended Load Line Limit and ARTS Improvement Program Analyses for Peach Bottom Atomic Power Station Units 2 and 3," Revision 2, March, 1995;
- 3. PECo-FMS-0001-A, "Steady-State Thermal Hydraulic Analysis of Peach Bottom Units 2 and 3 using the FIBWR Computer Code";
- 4. PECo-FMS-0002-A, "Method for Calculating Transient Critical Power Ratios for Boiling Water Reactors (RETRAN-TCPPECo)";
- 5. PECo-FMS-0003-A, "Steady-State Fuel Performance Methods Report";
(continued)
PBAPS UNIT 2 5.0-21 Amendment No. 210, 214, 236, 251
Reporting Requirements 5.6 5.6 Reporting Requirements 5.6.5 CORE OPERATING LIMITS REPORT (COLR) (continued)
- 7. PECo-FMS-0005-A, "Methods for Performing BWR Steady-State Reactor Physics Analysis"; I
- 8. PECo-FMS-0006-A, "Methods for Performing BWR Reload Safety Evaluations"; and I
- 9. NEDO-32465-A, "Reactor Stability Detect and Suppress Solutions Licensing Basis Methodology And Reload Applications," August 1996.
- c. The core operating limits shall be determined such that all applicable limits (e.g., fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.
- d. The COLR, including any midcycle revisions or supplements, shall be provided upon issuance for each reload cycle to the NRC.
5.6.6 Post Accident Monitoring (PAM) Instrumentation Report When a report is required by Condition B or F of LCO 3.3.3.1, "Post Accident Monitoring (PAM) Instrumentation," a report shall be submitted within the following 14 days. The report shall outline the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the Function to OPERABLE status.
PBAPS UNIT 2 5.0-22 Amendment No. 2+0, 214, 251
1I RPS Instrumentation 3.3.1.1 3.3 INSTRUMENTATION 3.3.1.1 Reactor Protection System (RPS) Instrumentation LCO 3.3.1.1 The RPS instrumentation for each Function in Table 3.3.1.1-1 shall be OPERABLE.
APPLICABILITY: According to Table 3.3.1.1-1.
ACTIONS
NOTE-------------------------------------
Separate Condition entry is allowed for each channel.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or more required A.1 Place channel in 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> channels inoperable. trip.
OiR A.2 -------- NOTE--------- 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> Not applicable for Functions 2.a, 2.b, 2.c, 2.d, or 2.f. I Place associated trip system in trip.
B. --------- NOTE--------- B.1 Place channel in one 6 hours0.25 days <br />0.0357 weeks <br />0.00822 months <br /> Not applicable for trip system in trip.
Functions 2.a, 2.b, 2.c, 2.d, or 2f. I One or more Functions B.2 Place one trip system 6 hours0.25 days <br />0.0357 weeks <br />0.00822 months <br /> with one or more in trip.
required channels inoperable in both trip systems.
(continued)
PBAPS UNIT 3 3.3-1 Amendment No. 214, 234, 25
RPS Instrumentation 3.3.1.1 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME H. As required by H.1 Initiate action to Immediately Required Action D.1 fully insert all and referenced in insertable control Table 3.3.1.1-1. rods in core cells containing one or more fuel assemblies.
I. As required by I.1 Initiate alternate 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> Required Action D.1 method to detect and and referenced in suppress thermal Table 3.3.1.1-1. hydraulic instability oscillations.
1.2 -------- NOTE--------
LCO 3.0.4 is not applicable.
Restore required 120 days channels to OPERABLE.
J. Required Action and J.1 Reduce THERMAL POWER 4 hours0.167 days <br />0.0238 weeks <br />0.00548 months <br /> associated Completion to <25X RTP.
Time of Condition I not met.
PBAPS UNIT 3 3.3-3 Amendment No. a4, 254
RPS Instrumentation 3.3.1.1 SURVEILLANCE REQUIREMENTS
--- --------- NOTES------------------------------------
- 1. Refer to Table 3.3.1.1-1 to determine which SRs apply for each RPS Function.
- 2. When a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours0.25 days <br />0.0357 weeks <br />0.00822 months <br /> provided the associated Function maintains RPS trip capability.
SURVEILLANCE FREQUENCY SR 3.3.1.1.1 Perform CHANNEL CHECK. 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> SR 3.3.1.1.2 ------------------NOTE-------------------
Not required to be performed until 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> after THERMAL POWER 2 25X RTP.
Verify the absolute difference between 7 days the average power range monitor (APRM) channels and the calculated power is s 2% RTP while operating at 2 25X RTP.
(continued)
PBAPS UNIT 3 3.3-3a Amendment No. 214, 154
RPS Instrumentation 3.3.1.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.1.1.9 Perform CHANNEL FUNCTIONAL TEST. 92 days SR 3.3.1.1.10 ------------------ NOTE-------------------
Radiation detectors are excluded.
Perform CHANNEL CALIBRATION. 92 days SR 3.3.1.1.11 ------------------ NOTES------------------
- 1. For Function 2.a, not required to be performed when entering MODE 2 from MODE I until 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> after entering MODE 2.
- 2. For Functions 2.b and 2.f, the CHANNEL FUNCTIONAL TEST includes the recirculation flow input processing, excluding the flow transmitters.
Perform CHANNEL FUNCTIONAL TEST. 184 days SR 3.3.1.1.12 ------------------ NOTES------------------
- 1. Neutron detectors are excluded.
- 2. For Function 1, not required to be performed when entering MODE 2 from MODE I until 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> after entering MODE 2.
- 3. For Functions 2.b and 2.f, the recirculation flow transmitters that feed the APRMs are included.
Perform CHANNEL CALIBRATION. 24 months (continued)
PBAPS UNIT 3 3.3-5 Amendment No.RP5 , 234, 254
4 r.
RPS Instrumentation 3.3.1.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.1.1.13 Verify Turbine Stop Valve-Closure and 24 months Turbine Control Valve Fast Closure, Trip Oil Pressure-Low Functions are not bypassed when THERMAL POWER is 2 29.5X RTP.
SR 3.3.1.1.14 Perform CHANNEL FUNCTIONAL TEST. 24 months SR 3.3.1.1.15 Perform CHANNEL CALIBRATION. 24 months SR 3.3.1.1.16 Calibrate each radiation detector. 24 months SR 3.3.1.1.17 Perform LOGIC SYSTEM FUNCTIONAL TEST. 24 months SR 3.3.1.1.18 Verify the RPS RESPONSE TIME is within 24 months limits.
SR 3.3.1.1.19 Verify OPRM is not bypassed when APRM 24 months Simulated Thermal Power is 229.5X and recirculation drive flow is <60X.
PBAPS UNIT 3 3.3-6 Amendment No. 234,250, 254
4 r RPS Instrumentation 3.3.1.1 Table 3.3.1.121 (page 1 of 3)
Reactor Protection System Instrumentation APPLICABLE CONDITIONS MODES OR REQUIRED REFERENCED OTHER CHANNELS FROM SPECIFIED PER TRIP REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS SYSTEM ACTION D.1 REQUIREMENTS VALUE
- 1. Uide Range Neutron Monitors
- a. Period-Short 2 3 t SR 3.3.1.1.1 > 13 seconds SR 3.3.1.1.5 SR 3.3.1.1.12 SR 3.3.1.1.17 SR 3.3.1.1.18 5(a) 3 H SR 3.3.1.1.1 2 13 seconds SR 3.3.1.1.6 SR 3.3.1.1.12 SR 3.3.1.1.17 SR 3.3.1.1.18
- b. Inop 2 3 G SR 3.3.1.1.5 NA SR 3.3.1.1.17 5(a) 3 H SR 3.3.1.1.6 NA SR 3.3.1.1.27
- 2. Average Power Range Monftars
- a. Neutron Flux-High 2 3(c) G SR 3.3.1.1.1 S 15.0 RTP (Setdown) SR 3.3.1.1.8 SR 3.3.1.1.11 SR 3.3.1.1.12 D. Simulated Thermal 1 3 (c) F SR 3.3.1.1.1 s 0.65 V Power-High SR 3.3.1.1.2 + 63.7S RTP(b) and s 118.0O RTP SR 3.3.1.1.8 SR 3.3.1.1.11 SR 3.3.1.1.12
- c. Neutron Flux-High 1 3(c) F SR 3.3.1.1.1 s 119.7S RTP SR 3.3.1.1.2 SR 3.3.1.1.8 SR 3.3.1.1.11 SR 3.3.1.1.12
- d. Inop 1.2 3 (c) t SR 3.3.1.1.11 NA
- e. 2-Out-Of-4 Voter 1.2 2 C SR 3.3.1.1.1 NA SR 3.3.1.1.11 SR 3.3.1.1.17 SR 3.3.1.1.18
- f. OPRM Upscale 225S NAWd) 3 (c) I SR 3.3.1.1.1 RTP SR 3.3.1.1.8 SR 3.3.1.1.11 SR 3.3.1.1.12 SR 3.3.1.1.19 (continued)
(a) WiYth any control rod withdrawn from a core cell containing one or more fuel assemblies.
(b) 0.65 (W - AU) + 63.71 RTP when reset for single loop operation per LCO 3.4.1. Recirculation Loops Operating., I Cc) Each APRM channel provides Inputs to both trip systems.
td) See COLR for OPRM period based detection algorithm (PBDA) setpoint limits. I PPAPS UNIT 3 3.3-7 Amendment No. 224, 259, 25'
k r Recirculation Loops Operating 3.4.1 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.1 Recirculation Loops Operating LCO 3.4.1 Two recirculation loops with matched flows shall be in operation. I DR One recirculation loop shall be in operation with the I following limits applied when the associated LCO is applicable:
- a. LCO 3.2.1, "AVERAGE PLANAR LINEAR HEAT GENERATION RATE (APLHGR),' single loop operation limits specified in the I COLR;
- b. LCO 3.2.2, "MINIMUM CRITICAL POWER RATIO (MCPR)," single loop operation limits specified in the COLR; and
Instrumentation," Function 2.b (Average Power Range Monitors Simulated Thermal Power-High), Allowable Value of Table 3.3.1.1-1 is reset for single loop operation.
NOTE---------------
Required limit modifications for single recirculation loop operation may be delayed for up to 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> after transition from two recirculation loop operation to single recirculation loop operation.
APPLICABILITY: MODES 1 and 2.
PBAPS UNIT 3 3 .4-1 Amendment No.-24, 234,25
i I Recirculation Loops Operating 3.4.1 ACTIONS THIS PAGE LEFT BLANK INTENTIONALLY (The contents of this page have been deleted)
PBAPS UNIT 3 3.4-2 Amendment No. 26A, 254
Recirculation Loops Operating 3.4.1 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME I
A. Requirements of the A.1 Satisfy the 24 hours1 days <br />0.143 weeks <br />0.0329 months <br /> LCO not met. requirements of the LCO.
B. No recirculation loops B.1 Be in MODE 3. 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> in operation.
Required Action and associated Completion Time of Condition A not met.
I PBAPS UNIT 3 3.4-3 Amendment No.-24, 254
Recirculation Loops Operating 3.4.1 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY 4
SR 3.4.1.1 -------------------- NOTE----------
Not required to be performed until 24 hours1 days <br />0.143 weeks <br />0.0329 months <br /> after both recirculation loops are in operation.
Verify recirculation loop jet pump flow 24 hours1 days <br />0.143 weeks <br />0.0329 months <br /> mismatch with both recirculation loops in operation is:
- a. s 10.25 X 106 ibm/hr when operating at
< 71.75 X 106 lbm/hr; and
- b. 5 5.125 X 106 ibm/hr when operating at 2 71.75 X 106 ibm/hr.
PBAPS UNIT 3 3.4-4 Amendment No. ?1-, 254
Recirculation Loops Operating 3.4.1 THIS PAGE LEFT BLANK INTENTIONALLY (The contents of this page have been deleted)
PBAPS UNIT 3 3.4-5 Amendment No. P4, 254
RPS Instrumentation B 3.3.1.1 BASES APPLICABLE L.b. Wide Range Neutron Monitor-mnop (continued)
SAFETY ANALYSES, LCO, and Six channels of the Wide Range Neutron Monitor-Inop APPLICABILITY Function, with three channels in each trip system, are required to be OPERABLE to ensure that no single instrument failure will preclude a scram from this Function on a valid signal. Since this Function is not assumed in the safety analysis, there is no Allowable Value for this Function.
This Function is required to be OPERABLE when the Wide Range Neutron Monitor Period-Short Function is required.
Average Power Range Monitor (APRM)
The APRM channels provide the primary indication of neutron flux within the core and respond almost instantaneously to neutron flux increases. The APRM channels receive input signals from the local power range monitors (LPRMs) within the reactor core to provide an indication of the power distribution and local power changes. The APRM channels average these LPRM signals to provide a continuous indication of average reactor power from a few percent to greater than RTP. Each APRM also includes an Oscillation Power Range Monitor (OPRM) Upscale Function which monitors small groups of LPRM signals to detect thermal-hydraulic instabilities.
The APRM System is divided into four APRM channels and four 2-out-of-4 voter channels. Each APRM channel provides inputs to each of the four voter channels. The four voter channels are divided into two groups of two each, with each group of two providing inputs to one RPS trip system. The system is designed to allow one APRM channel, but no voter channels to be bypassed. A trip from any one unbypassed APRM will result in a 'half-trip' in all four of the voter channels, but no trip inputs to either RPS trip system.
APRM trip Functions 2.a, 2.b, 2.c, and 2.d are voted independently from OPRM Upscale Function 2.f. Therefore, an yFunction 2.a, 2.b, 2.c, or 2.d trip from any two unpassed APRM channels will result in a full trip in each of the four voter channels, which in turn results in two trip inputs into each RPS trip system logic channel (Al, A2, B1, and B2), thus resulting in a full scram signal.
Similarly, a Function 2.f trip from any two unbypassed APRM channels will result in a full trip from each of the four voter channels. Three of the four APRM channels and all four of the voter channels are required to be OPERABLE to ensure that no single failure will preclude a scram on a valid signal. In addition, to Provide adequate coverage of the entire core consistent with the design bases for the APRM Functions L.a, 2.b, and 2.c, at least 20 LPRM inputs, with at least three LPRM inputs from each of the four axial levels at which the LPRMs are located, must be operable for each APRM channel, and the number of LPRM inputs that have become inoperable (and bypassed) since the last APRM calibration (SR 3.3.1.1.2) must be less than ten for each APRM channel. For the OPRM Upscale, Function 2.f, LPRMs are assigned to "cells" of 3 or 4 detectors. A minimum of 25 cells, each with a minimum of 2 OPERABLE LPRMs, must be OPERABLE for the OPRM Upscale Function 2.f to be OPERABLE.
(continued)
PBAPS UNIT 3 B 3.3-7 Revision No.
0 RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2a. Average Power Range Monitor Neutron Flux-High SAFETY ANALYSES, -(Setdown) (continued)
LCO, and APPLICABILITY For operation at low power (i.e., MODE 2), the Average Power Range Monitor Neutron Flux-High (Setdown) Function is capable of generating a trip signal that prevents fuel damage resulting from abnormal operating transients in this power range. For most operation at low power levels, the Average Power Range Monitor Neutron Flux-High (Setdown)
Function will provide a secondary scram to the Wide Range Neutron Monitor Period-Short Function because of the relative setpoints. At higher power levels, it is possible that the Average Power Range Monitor Neutron Flux-High (Setdown) Function will provide the primary trip signal for a corewide increase in power.
No specific safety analyses take direct credit for the Average Power Range Monitor Neutron Flux-High (Setdown)
Function. However, this Function indirectly ensures that before the reactor mode switch is placed in the run position, reactor power does not exceed 25% RTP (SL 2.1.1.1) when operating at low reactor pressure and low core flow.
Therefore, it indirectly prevents fuel damage during significant reactivity increases with THERMAL POWER
< 25% RTP.
The Allowable Value is based on preventing significant increases in power when THERMAL POWER is < 25% RTP.
The Average Power Range Monitor Neutron Flux-High (Setdown)
Function must be OPERABLE during MODE 2 when control rods may be withdrawn since the potential for criticality exists.
In MODE 1, the Average Power Range Monitor Neutron Flux-High Function provides protection against reactivity transients and the RWM and rod block monitor protect against control rod withdrawal error events.
2.b. Average Power Range Monitor Simulated Thermal Power-High The Average Power Range Monitor Simulated Thermal Power-High Function monitors average neutron flux to approximate the THERMAL POWER being transferred to the reactor coolant. The APRM neutron flux is electronically filtered with a time constant representative of the fuel heat transfer dynamics to generate a signal proportional to the THERMAL POWER in the reactor. The trip level is varied as a function of recirculation drive flow (i.e., at lower core flows, the setpoint is reduced proportional to the reduction in power experienced as core flow is reduced with a fixed control rod pattern) but is clamped at an upper limit that is always lower than the Average Power Range Monitor Neutron Flux-High Function Allowable Value. A note is included, applicable when the plant is in single recirculation loop operation per LCO 3.4.1, which requires the flow value, used in the Allowable Value equation, be reduced by AW. The value of AW (continued)
PBAPS UNIT 3 B 3.3-8 Revision No.
-I I RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.b. Average Power Range Monitor Simulated Thermal SAFETY ANALYSES, Power-High (continued)
LCO, and APPLICABILITY is established to conservatively bound the inaccuracy created in the core flow/drive flow correlation due to back flow in the jet pumps associated with the inactive recirculation loop. The Allowable Value thus maintains thermal margins essentially unchanged from those for two loop operation. The value of aW is plant specific and is defined in plant procedures. The Allowable Value equation for single loop operation is only valid for flows down to W = AW; the Allowable Value does not go below 63.7Z RTP. This is acceptable because back flow in the inactive recirculation loop is only evident with drive flows of approximately 35X or greater (Reference 19).
The Average Power Range Monitor Simulated Thermal Power-High Function is not specifically credited in the safety analysis but is intended to provide an additional margin of protection from transient induced fuel damage during operation where recirculation flow is reduced to below the minimum required for rated power operation. The Average Power Range Monitor Simulated Thermal Power-High Function provides protection against transients where THERMAL POWER increases slowly (such as the loss of feedwater heating event) and protects the fuel cladding integrity by ensuring that the MCPR SL is not exceeded. During these events, the THERMAL POWER increase does not significantly lag the neutron flux scram. For rapid neutron flux increase events, the THERMAL POWER lags the neutron flux and the Average Power Range Monitor Neutron Flux-High Function will provide a scram signal before the Average Power Range Monitor Simulated Thermal Power-High Function setpoint is exceeded.
Each APRM channel uses one total drive flow signal representative of total core flow. The total drive flow signal is generated by the flow processing logic, part of the APRM channel, by summing up the flow calculated from two flow transmitter signal inputs, one from each of the two recirculation loop flows. The flow processing logic OPERABILITY is part of the APRM channel OPERABILITY requirements for this Function. The APRM flow processing logic is considered inoperable whenever it cannot deliver a flow signal less than or equal to actual Recirculation flow conditions for all steady state and transient reactor conditions while in Mode 1. Reduced or Downscale flow conditions due to planned maintenance or testing activities during derated plant conditions (i.e. end of cycle coast down) will result in conservative setpoints for the APRM Simulated Thermal Power-High function, thus maintaining that function operable.
(continued)
PBAPS UNIT 3 B 3.3-9 Revision No.
RP Intuetio RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.d. Average Power Range Monitor-Inop SAFETY ANALYSES, LCO, and Three of the four APRM channels are required to be OPERABLE APPLICABILITY for each of the APRM Functions. This Function (Inop)
(continued) provides assurance that the minimum number of APRM channels are OPERABLE.
For any APRM channel, any time its mode switch is not in the "Operate" position, an APRM module required to issue a trip is unplugged or the automatic self-test system detects a critical fault with the APRM channel, an Inop trip is sent to all four voter channels. Inop trips from two or more unbypassed APRM channels result in a trip output from each of the four voter channels to it's associated trip system.
This Function was not specifically credited in the accident analysis, but it is retained for the overall redundancy and diversity of the RPS as required by the NRC approved licensing basis.
There is no Allowable Value for this Function.
This Function is required to be OPERABLE in the MODES where the APRM Functions are required.
- 2.e. 2-Out-Of-4 Voter The 2-Out-Of-4 Voter Function provides the interface between the APRM Functions, including the OPRM Upscale Function, and the final RPS trip system logic. As sucN, it is required to be OPERABLE in the MODES where the APRM Functions are required and is necessary to support the safety analysis applicable to each of those Functions. Therefore the 2-Out-Of-4 Voter Function needs to be OPERABLE in M6DES 1 and 2.
All four voter channels are required to be OPERABLE. Each voter channel includes self-diagnostic functions. If any voter channel detects a critical fault in its own processing, a trip is issued from that voter channel to the associated trip system.
The 2-Out-Of-4 Logic Module includes 2-Out-Of-4 Voter hardware and the APRM Interface hardware. The 2-Out-Of-4 Voter Function 2.e votes APRM Functions 2.a, 2.b, 2.c, and 2.d independently of Function 2.f. This voting is accomplished by the 2-Out-Of-4 Voter hardware in the 2-Out-Of-4 Logic Module. Each 2-Out-Of-4 Voter includes two redundant sets of outputs to RPS. Each output set contains two independent contacts; one contact for Functions 2.a 2.b, 2.c and 2.d, and the other contact for Function 2.f The analysis in Reference 12 took credit for this redundancy in the justification of the 12-hour Completion Time for Condition A, so the voter Function 2.e must be declared'inoperable if any of its functionality is inoperable. However, the voter Function 2.e does not need to be declared inoperable due to any failure affecting only the plant interface portions of the 2-Out-Of-4 Logic Module that are not necessary to perform the 2-Out-Of-4 Voter function.
There is no Allowable Value for this Function.
(continued)
PBAPS UNIT 3 B 3.3-12 Revision No..
e RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.f. Oscillation Power Range Monitor (OPRM) Upscale SAFETY ANALYSES, LCO, and The OPRM Upscale Function provides compliance with 10 CFR APPLICABILITY 50, Appendix A, General Design Criteria (GDC) 10 and 12, (continued) thereby providing protection from exceeding the fuel MCPR safety limit (SL) due to anticipated thermal-hydraulic power oscillations.
References 14, 15 and 16 describe three algorithms for detecting thermal-hydraulic instability related neutron flux oscillations: the period based detection algorithm MPBDA),
the amplitude based algorithm (ABA), and the growth rate algorithm (GRA). All three are implemented in the OPRM Upscale Function, but the safety analysis takes credit only for the PBDA. The remaining algorithms provide defense in depth and additional protection against unanticipated oscillations. OPRM Upscale Function OPERABILITY for Technical Specifications purposes is based only on the PBDA.
The OPRM Upscale Function receives input signals from the local power range monitors (LPRMs) within the reactor core, which are combined into "cells" for evaluation by the OPRM algorithms. Each channel is capable of detecting thermal-hydraulic instabilities, by detecting the related neutron flux oscillations, and issuing a trip signal before the MCPR SL is exceeded. Three of the four channels are required to be OPERABLE.
The OPRM Upscale trip is automatically enabled (bypass removed) when THERMAL POWER is 2 29.5% RTP, as indicated by the APRM Simulated Thermal Power, and reactor core flow is
< 60% of rated flow, as indicated by APRM measured recirculation drive flow. This is the operating region where actual thermal-hydraulic instability and related neutron flux oscillations may occur (Reference 18). These setpoints, which are sometimes referred to as the "auto-bypass" setpoints, establish the boundaries of the OPRM Upscale trip enabled region.
The OPRM Upscale Function is required to be OPERABLE when the plant is at 2 25% RTP. The 25% RTP level is selected to provide margin in the unlikely event that a reactor power increase transient occurring while the plant is operating below 29.5% RTP causes a power increase to or beyond the 29.5% APRM Simulated Thermal Power OPRM Upscale trip auto-enable setpoint without operator action. This OPERABILITY requirement assures that the OPRM Upscale trip auto-enable function will be OPERABLE when required.
(continued)
PBAPS UNIT 3 B 3.3-12a Revision No.
RPS Instrumentation B 3.3.1.1 BASES APPLICABLE 2.f. Oscillation Power Ranne Monitor (OPRM)
SAFETY ANALYSES, Upscale (continued)
LCO, and APPLICABILITY An OPRM Upscale trip is issued from an APRM channel when (continued) the PBDA in that channel detects oscillatory changes in the neutron flux, indicated by the combined signals of the LPRM detectors in a cell, with period confirmations and relative cell amplitude exceeding specified setpoints. One or more cells in a channel exceeding the trip conditions will result in a channel trip. An OPRM Upscale trip is also issued from the channel if either the GRA or ABA detects oscillatory changes in the neutron flux for one or more cells in that channel.
There are four "sets" of OPRM related setpoints or adjustment parameters: a) OPRM trip auto-enable setpoints for APRM Simulated Thermal Power (29.5X) and drive flow (60X); b) PBDA confirmation count and amplitude setpoints; c) PBDA tuning parameters; and d) GRA and ABA setpoints.
The first set, the OPRM auto-enable region setpoints, as discussed in the SR 3.3.1.1.19 Bases, are treated as nominal setpoints without the application of setpoint methodology per Reference 18. The settings, 29.5Z APRM Simulated Thermal Power and 60X drive flow, are defined (limit values) in and confirmed by SR 3.3.1.1.19. The second set, the OPRM PBDA trip setpoints, are established in accordance with methodologies defined in Reference 16, and are documented in the COLR. There are no allowable values for these setpoints.
The third set, the OPRM PBDA "tuning" parameters, are established or adjusted In accordance with and controlled by PBAPS procedures. The fourth set, the GRA and ABA setpolnts, in accordance with References 14, 15, and 16, are established as nominal values only, and are controlled by PBAPS procedures.
Ccontinued)
PBAPS UNIT 3 B 3.3-12b Revision No.
RPS Instrumentation B 3.3.1.1 BASES ACTIONS A.1 andLA.2 (continued)
Function's inoperable channel is in one trip system and the Function still maintains RPS trip capability (refer to Required Actions B.1, B.2, and C.1 Bases). If the inoperable channel cannot be restored to OPERABLE status within the allowable out of service time, the channel or the associated trip system must be placed in the tripped condition per Required Actions A.1 and A.2. Placing the inoperable channel in trip (or the associated trip system in trip) would conservatively compensate for the inoperability, restore capability to accommodate a single failure, and allow operation to continue. Alternatively, if it is not desired to place the channel (or trip system) in trip (e.g.,
as in the case where placing the inoperable channel in trip would result in a full scram), Condition D must be entered and its Required Action taken.
As noted, Action A.2 is not applicable for APRM Functions 2.a, 2.b, 2.c, 2.d, or 2.f. Inoperability of one required APRM channel affects both trip systems. For that condition, Required Action A.1 must be satisfied, and is the only action (other than restoring operability) that will restore capability to accommodate a single failure. Inoperability of more than one required APRM channel of the same trip function results in loss of trip capability and entry into Condition C, as well as entery into Condition A for each channel.
B-1 and B.-Z Condition B exists when, for any one or more Functions, at least one required channel is inoperable in each trip system. In this condition, provided at least one channel per trip system is OPERABLE, the RPS still maintains trip capability for that Function, but cannot accommodate a single failure in either trip system.
Required Actions B.1 and B.2 limit the time the RPS scram logic, for any Function, would not accommodate single failure in both trip systems (e.g., one-out-of-one and one-out-of-one arrangement for a typical four channel Function). The reduced reliability of this logic arrangement was not evaluated in References 9, 12 or 13 for the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Completion Time. Within the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowance, the associated Function will have all required channels OPERABLE or in trip (or any combination) in one trip system.
(continued)
PBAPS UNIT 3 B 3.3-24 B3Revision No.
RISIntumnato RPS Instrumentation B 3.3.1.1 BASES ACTIONS B.1 and BI (continued)
Completing one of these Required Actions restores RPS to a reliability level equivalent to that evaluated in References 9, 12 or 13, which justified a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> allowable out of service time as presented in Condition A. The trip system in the more degraded state should be placed in trip or, alternatively, all the inoperable channels in that trip system should be placed in trip (e.g., a trip system with two inoperable channels could be in a more degraded state than a trip system with four inoperable channels if the two inoperable channels are in the same Function while the four inoperable channels are all in different Functions). The decision of which trip system is in the more degraded state should be based on prudent judgment and take into account current plant conditions (i.e., what MODE the plant is in).
If this action would result in a scram or RPT, it is permissible to place the other trip system or its inoperable channels in trip.
The 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Completion Time is judged acceptable based on the remaining capability to trip, the diversity of the sensors available to provide the trip signals, the low probability of extensive numbers of inoperabilities affecting all diverse Functions, and the low probability of an event requiring the initiation of a scram.
Alternately, if it is not desired to place the inoperable channels (or one trip system) in trip (e.g., as in the case where placing the inoperable channel or associated trip system in trip would result in a scram, Condition D must be entered and its Required Action taken.
As noted, Condition B is not applicable for APRM Functions 2.a, 2.b, 2.c, 2.d, or 2.f. Inoperability of an APRM channel affects both trip systems and is not associated with a specific trip system as are the APRM 2-Out-Of-4 voter and other non-APRM channels for which Condition B applies. For an inoperable APRM channel, Required Action A.1 must be satisfied, and is the only action (other than restoring operability) that will restore capability to accommodate a single failure. Inoperability of a Function in more than one requited APRM channel results in loss of trip capability for that Function and entry into Condition C, as well as entry into Condition A for each channel. Because Condition A and C provide Required Actions that are appropriate for the inoperability.of APRM Functions 2.a, 2.b, 2.c, 2.d, or 2.f, and these functions are not associated with specific trip systems as are the APRM 2-Out-Of-4 voter and other non-APRM channels, Condition B does not apply.
(continued)
PBAPS UNIT 3 B 3.3-25 Revision No.-
L r i RPS Instrumentation B 3.3.1.1 BASES ACTIONS E.1. F.1. G.1. and J.1 (continued)
If the channel(s) is not restored to OPERABLE status or placed in trip (or the associated trip system placed in trip) within the allowed Completion Time, the plant must be placed in a MODE or other specified condition in which the LCO does not apply. The allowed Completion Times are reasonable, based on operating experience, to reach the specified condition from full power conditions in an orderly manner and without challenging plant systems. In addition, the Completion Time of Required Actions E.1 and J.1 are consistent with the Completion Time provided in LCO 3.2.2, "MINIMUM CRITICAL POWER RATIO (MCPR)."
If the channel(s) is not restored to OPERABLE status or placed in trip (or the associated trip system placed in trip) within the allowed Completion Time, the plant must be placed in a MODE or other specified condition in which the LCO does not apply. This is done by immediately initiating action to fully insert all insertable control rods in core cells containing one or more fuel assemblies. Control rods in core cells containing no fuel assemblies do not affect the reactivity of the core and are, therefore, not required to be inserted. Action must continue until all insertable control rods in core cells containing one or more fuel assemblies are fully inserted.
If OPRM Upscale trip capability is not maintained, Condition I exists. References 12 and 13 justified use of alternate methods to detect and suppress oscillations for a limited period of time. The alternate methods are procedurally established consistent with the guidelines identified in Reference 17 requiring manual operator action to scram the plant if certain predefined events occur. The 12-hour allowed Completion Time for Required Action 1.1 is based on engineering judgment to allow orderly transition to the alternate methods while limiting the period of time during which no automatic or alternate detect and suppress trip capability is formally in place. Based on the small probability of an instability event occurring at all, the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> duration is judged to be reasonable.
(conti nupd)
PBAPS UNIT 3 8 3.3-27 Revision No..
r RPS Instrumentation B 3.3.1.1 BASES ACTIONS Ti (continued)
The alternate method to detect and suppress oscillations implemented in accordance with 1.1 was evaluated (References 12 and 13) based on use up to 120 days only. The evaluation, based on engineering judgment, concluded that the likelihood of an instability event that could not be adequately handled by the alternate methods during this 120-day period was negligibly small. The 120-day period is intended to be an outside limit to allow for the case where design changes or extensive analysis might be required to understand or correct some unanticipated characteristic of the instability detection algorithms or equipment. This action is not intended and was not evaluated as a routine alternative to returning failed or inoperable equipment to OPERABLE status.
Correction of routine equipment failure or inoperability is expected to normally be accomplished within the completion times allowed for Actions for Condition A.
A note is provided to indicate that LCO 3.0.4 is not applicable. The intent of that note is to allow plant start-up while within the 120-day completion time for action 1.2. The primary purpose of this exclusion is to allow an orderly completion of design and verification activities, in the event of a required design change, without undue impact on plant operation.
SURVEILLANCE As noted at the beginning of the SRs, the SRs for each RPS REQUIREMENTS instrumentation Function are located in the SRs column of Table 3.3.1.1-1.
The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours0.25 days <br />0.0357 weeks <br />0.00822 months <br />, provided the associated Function maintains RPS trip capability. Upon completion of the Surveillance, or expiration of the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the reliability analysis (Refs. 9, 12 & 13) assumption of the average time required to perform channel Surveillance.
That analysis demonstrated that the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> testing allowance does not significantly reduce the probability that the RPS will trip when necessary.
(continued)
PBAPS UNIT 3 B 3.3-27a Revision No.
RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.9 and SR 3.3.1.1.14 (continued)
REQUIREMENTS In addition, Function 5 and 7 instruments are not accessible while the unit is operating at power due to high radiation and the installed indication instrumentation does not Provide accurate indication of the trip setting. For the Function 9 channels, verification that the trip settings are less than or equal to the specified Allowable Value during the CHANNEL FUNCTIONAL TEST is not required since the instruments are not accessible while the unit is operating at power due to high radiation and the installed indication instrumentation does not provided accurate indication of the trip setting. Waiver of these verifications for the above functions is considered acceptable since the magnitude of drift assumed in the setpoint calculation is based on a 24 month calibration interval. The 92 day Frequency of SR 3.3.1.1.9 is based on the reliability analysis of Reference 9.
The 24 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power.
Operating experience has shown that these components will pass the Surveillance when performed at the 24 month Frequency.
SR 3.3.1.1.10. SR 3.3.1.1.12. SR 3.3.1.1.15.
and SR 3.3.1.1.16 A CHANNEL CALIBRATION is a complete check of the instrument loop and the sensor. This test verifies that the channel responds to the measured parameter within the necessary range and accuracy. CHANNEL CALIBRATION leaves the channel ad usted to account for instrument drifts between successive calibrations, consistent with the current plant specific setpoint methodology.
As noted for SR 3.3.1.1.10, radiation detectors are excluded from CHANNEL CALIBRATION due to ALARA reasons (when the plant is operating, the radiation detectors are generally in a high radiation area; the steam tunnel). This exclusion is acceptable because the radiation detectors are passive devices, with minimal drift. To complete the radiation CHANNEL CALIBRATION, SR 3.3.1.1.16 requires that the radiation detectors be calibrated on a once per 24 months Frequency.
The once per 92 days Frequency of SR 3.3.1.1.10 is conservative with respect to the magnitude of equipment drift assumed in the setpoint analysis. The Frequency of SR 3.3.1.1.16 is based upon the assumption of a 24-month calibration interval used in the determination of the equipment drift in the setpoint analysis.
As noted for SR 3.3.1.1.12, neutron detectors are excluded from CHANNEL CALIBRATION because they are passive devices, with minimal drift, and because of the difficulty of simulating a meaningful signal. Changes in (continued)
PBAPS UNIT 3 B 3.3-32 Revision No.
RPS Instrumentation RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.10. SR 3.3.1.1.12. SR 3.3.1.1.15.
REQUIREMENTS and SR 3.3.1.1.16 (continued) neutron detector sensitivity-are compensated for by performing the 7 day calorimetric calibration (SR 3.3.1.1.2) and the 1000 MWDIT LPRM calibration against the TIPs (SR 3.3.1.1.8).
A second note is provided for SR 3.3.1.1.12 that allows the WRNM SR to be performed within 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> of entering MODE 2 from MODE 1. Testing of the MODE 2 WRNM Functions cannot be performed in MODE 1 without utilizing jumpers, lifted leads or movable links. This Note allows entry into MODE 2 from MODE 1, if the 24 month Frequency is not met per SR 3.0.2.
Twelve hours is based on operating experience and in consideration of providing a reasonable time in which to complete the SR.
A third note is provided for SR 3.3.1.1.12 that includes in the SR the recirculation flow (drive flow) transmitters, which supply the flow signal to the APRMs. The APRM Simulated Thermal Power-High Function (Function 2.b) and the OPRM Upscale Function (Function 2.f), both require a valid drive flow signal. The APRM Simulated Thermal Power-High Function uses drive flow to vary the trip setpoint. The OPRM Upscale Function uses drive flow to automatically enable or bypass the OPRM Upscale trip output to RPS. A CHANNEL CALIBRATION of the APRM drive flow signal requires both calibrating the drive flow transmitters and establishing a valid drive flow /
core flow relationship. The drive flow /core flow relationship is established once per refuel 'cycle, while operating at or near rated power and flow conditions. This method of correlating core flow and drive flow is consistent with GE recommendations. Changes throughout the cycle in the drive flow / core flow relationship due to the changing thermal hydraulic operating conditions of the core are accounted for in the margins included in the bases or analyses used to establish the setpoints for the APRM Simulated Thermal Power-High Function and the OPRM Upscale Function.
The Frequencies of SR 3.3.1.1.12 and SR 3.3.1.1.15 are based upon the assumption of a 24-month calibration interval used in the determination of the equipment drift in the setpoint analysis.
SR 33111 A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the entire channel will perform the (continued)
PBAPS UNIT 3 B 3.3-33 Revision No. -.
RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.11 (continued)
REQUI REMENTS intended function. For the APRM Functions, this test supplements the automatic self-test functions that operate continuously in the APRM and voter channels. The scope of the APRM CHANNEL FUNCTIONAL TEST is limited to verification of system trip output hardware. Software controlled functions are tested only incidentally. Automatic internal self-test functions check the EPROMs in which the software-controlled logic is defined. Any changes in the EPROMs will be detected by the self-test function resulting in a trip and/or alarm condition. The APRM CHANNEL FUNCTIONAL TEST covers the APRM channels (including recirculation flow processing - applicable to Function 2.b and the auto-enable portion of Function 2.f only), the 2-Out-Of-4 voter channels, and the interface connections into the RPS trip systems from the voter channels. Any setpoint adjustment shall be consistent with the assumptions of the current plant specific setpoint methodology. The 184 day Frequency of SR 3.3.1.1.11 is based on the reliability analyses of References 12 and 13. (NOTE: The actual voting logic of the 2-Out-Of-4 Voter Function is tested as part of SR 3.3.1.1.17. The actual auto-enable setpoints for the OPRM Upscale trip are confirmed by SR 3.3.1.1.19.)
A Note is provided for Function 2.a that requires this SR to be performed within 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> of entering MODE 2 from MODE 1.
Testing of the MODE 2 APRM Function cannot be performed in MODE 1 without utilizing jumpers or lifted leads. This Note allows entry into MODE 2 from MODE 1 if the associated Frequency is not met per SR 3.0.2.
A second Note is provided for Function 2.b that clarifies that the CHANNEL FUNCTIONAL TEST for Function 2.b includes testing of the recirculation flow processing electronics, excluding the flow transmitters.
SR 3.3.1.1.13 This SR ensures that scrams initiated from the Turbine Stop Valve-Closure and Turbine Control Valve Fast Closure, Trip Oil Pressure-Low Functions will not be inadvertently bypassed when THERMAL POWER is 2 29.5% RTP. This involves calibration of the bypass channels. Adequate margins for the instrument setpoint methodologies are incorporated into the Allowable Value (: 28.9% RTP which is equivalent to s 138.4 psig as measured from turbine first stage pressure) and the actual setpoint. Because main turbine bypass flow can affect this setpoint nonconservatively (THERMAL POWER is derived from turbine first stage pressure), the main turbine bypass valves must remain closed during the calibration at THERMAL POWER 2 29.5% RTP to ensure that the calibration is valid.
If any bypass channel's setpoint is nonconservative (i.e.,
the Functions are bypassed at 2 29.5% RTP, either due to open main turbine bypass valve(s) or other reasons), then the (eontniniued)
Revision No..
B 3.3-34 PBAPS UNIT 3 PBAPS UNIT 3 B 3.3-34 Revision No.-
RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.13 (continued)
REQUIREMENTS affected Turbine Stop Valve-Closure and Turbine Control Valve Fast Closure, Trip Oil Pressure-Low Functions are considered inoperable. Alternatively, the bypass channel can be placed in the conservative condition (nonbypass). If placed in the nonbypass condition, this SR is met and the channel is considered OPERABLE.
The Frequency of 24 months is based on engineering judgment and reliability of the components.
SR 3.3.1.1.17 The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the OPERABILITY of the required trip logic for a specific channel. The functional testing of control rods (LCO 3.1.3), and SDV vent and drain valves (LCO 3.1.8),
overlaps this Surveillance to provide complete testing of the assumed safety function.
The 24 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power.
Operating experience has shown that these components will pass the Surveillance when performed at the 24 month Frequency.
The LOGIC SYSTEM FUNCTIONAL TEST for APRM Function 2.e simulates APRM and OPRM trip conditions at the 2-Out-Of-4 voter channel inputs to check all combinations of two tripped inputs to the 2-Out-Of-4 logic in the voter channels and APRM related redundant RPS relays.
SR 3.3.1.1.18 This SR ensures that the individual channel response times are maintained less than or equal to the original design value. The RPS RESPONSE TIME acceptance criterion is included in Reference 11.
RPS RESPONSE TIME tests are conducted on a 24 month Frequency. The 24 month Frequency is consistent with the PBAPS refueling cycle and is based upon plant operating experience, which shows that random failures of instrumentation components causing serious response time degradation, but not channel failure, are infrequent occurrences.
(continued)
PBAPS UNIT 3 B 3.3-35 Revision No. --
RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE SR 3.3.1.1.19 REQUIREMENTS (continued) This surveillance involves confirming the OPRM Upscale trip auto-enable setpoints. The auto-enable setpoint values are considered to be nominal values as discussed in Reference 18.
This surveillance ensures that the OPRM Upscale trip is enabled (not bypassed) for the correct values of APRM Simulated Thermal Power and recirculation drive flow. Other surveillances ensure that the APRM Simulated Thermal Power and recirculation drive flow properly correlate with THERMAL POWER (SR 3.3.1.1.2) and core flow (SR 3.3.1.1.12),
respectively.
If any auto-enable setpoint is nonconservative (i.e., the OPRM Upscale trip is bypassed when APRM Simulated Thermal Power 229.5X and recirculation drive flow < 60X), then the affected channel is considered inoperable for the OPRM Upscale Function. Alternatively, the OPRM Upscale trip auto-enable setpoint(s) may be adjusted to place the channel in a conservative condition (not bypassed). If the OPRM Upscale trip is placed in the not-bypassed condition, this SR is met and the channel is considered OPERABLE.
The Frequency of 24 months is based on engineering judgment and reliability of the components.
REFERENCES 1. UFSAR, Section 7.2.
- 2. UFSAR, Chapter 14.
- 3. NEDO-32368, "Nuclear Measurement Analysis and Control Wide Range Neutron Monitoring System Licensing Report for Peach Bottom Atomic Power Station, Units 2 and 3,"
November 1994.
- 4. NEDC-32183P, "Power Rerate Safety Analysis Report for Peach Bottom 2 & 3," dated May 1993.
- 5. UFSAR, Section 14.6.2.
- 6. UFSAR, Section 14.5.4.
- 7. UFSAR, Section 14.5.1.
- 8. P. Check (NRC) letter to G. Lainas (NRC), "BWR Scram Discharge System Safety Evaluation," December 1, 1980.
- 9. NEDO-30851-P-A , "Technical Specification Improvement Analyses for BWR Reactor Protection System,"
March 1988.
(continued)
PBAPS UNIT 3 B 3.3-36 Revision No.
4 '-
RPS Instrumentation B 3.3.1.1 BASES REFERENCES 10. MDE-87-0485-1, "Technical Specification Improvement (continued) Analysis for the Reactor Protection System for Peach Bottom Atomic Power Station Units 2 and 3," October 1987.
- 11. UFSAR, Section 7.2.3.9.
- 12. NEDC-3241OP-A, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM)
Retrofit Plus Option III Stability Trip Function",
October 1995.
- 13. NEDC-32410P Supplement 1, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function, Supplement 1", November 1997.
- 14. NEDO-31960-A, "BWR Owners' Group Long-Term Stability Solutions Licensing Methodology," November 1995.
- 15. NEDO-31960-A, Supplement 1, "BWR Owners' Group Long-Term Stability Solutions Licensing Methodology,"
November 1995.
- 16. NEDO-32465-A, "Reactor Stability Detect and Suppress Solutions Licensing Basis Methodology And Reload Applications," August 1996.
- 17. Letter, L. A. England (BWROG) to M. J. Virgilio, "BWR Owners' Group Guidelines for Stability Interim Corrective Action," June 6, 1994.
Phillips (NRC), "Guidelines for Stability Option III
'Enable Region' (TAC M92882)," September 17, 1996.
- 19. NEDO-24229-1, "Peach Bottom Atomic Power Station Units 2 and 3 Single-Loop Operation," May 1980.
PBAPS UNIT 3 B 3.3-36a Revision No. HI
4 -.
Recirculation Loops Operating B 3.4.1 BASES APPLICABLE Plant specific LOCA and average power range monitor/rod SAFETY ANALYSES block monitor Technical Specification/maximum extended load (continued) line limit analyses have been performed assuming only one operating recirculation loop. These'analyses demonstrate that, in the event of a LOCA caused by a pipe break in the operating recirculation loop, the Emergency Core Cooling System response will provide adequate core cooling (Refs. 2, 3, and 4).
The transient analyses of Chapter 14 of the UFSAR have also been performed for single recirculation loop operation (Ref. 5) and demonstrate sufficient flow coastdown characteristics to maintain fuel thermal margins during the abnormal operational transients analyzed provided the MCPR requirements are modified. During single recirculation loop operation, modification to the Reactor Protection System (RPS) average power range monitor (APRM) instrument setpoints is also required to account for the different relationships between recirculation drive flow and reactor core flow. The MCPR limits and APLHGR limits (power-dependent APLHGR multipliers, MAPFACp, and flow-dependent APLHGR multipliers, MAPFACf) for single loop operation are specified in the COLR. The APRM Simulated Thermal Power-High Allowable Value is in LCO 3.3.1.1, "Reactor Protection System (RPS) Instrumentation."
(continued)
PBAPS UNIT 3 B 3.4-3 Revision No.
q e Recirculation Loops Operating B 3.4.1 BASES APPLICABLE SAFETY ANALYSES (continued)
Recirculation loops operating satisfies Criterion 2 of the NRC Policy Statement.
LCO Two recirculation loops are normally required to be in operation with their flows matched within the limits specified in SR 3.4.1.1 to ensure that during a LOCA caused by a break of the piping of one recirculation loop the (continued)
PBAPS UNIT 3 B 3.4-4 Revision No.
Loops Operating Recirculation Recirculation Loops Operating B 3.4.1 BASES LCO assumptions of the LOCA analysis are satisfied.
Alternatively, with only one recirculation loop in operation, modifications to the required APLHGR limits (power- and flow-dependent APLHGR multipliers, MAPFAC, and MAPFACf, respectively of LCO 3.2.1, "AVERAGE PLANAR LINEAR HEAT GENERATION RATE (APLHGR)"), MCPR limits (LCO 3.2.2, "MINIMUM CRITICAL POWER RATIO (MCPR)") and APRM Simulated Thermal Power-High Allowable Value CLCO 3.3.1.1) must be applied to allow continued operation consistent with the assumptions of Reference 5.
The LCO is modified by a Note which allows up to 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> before having to put in effect the required modifications to required limits after a change in the reactor operating conditions from two recirculation loops operating to single recirculation loop operation. If the required limits are not in compliance with the applicable requirements at the end of this period, the associated equipment must be declared inoperable or the limits "not satisfied," and the ACTIONS required by nonconformance with the applicable specifications implemented. This time is provided due to the need to stabilize operation with one recirculation loop, including the procedural steps necessary to limit flow in the operating loop, and the complexity and detail required to fully implement and confirm the required limit modifications.
APPLICABILITY In MODES 1 and 2, requirements for operation of the Reactor Coolant Recirculation System are necessary since there is considerable energy in the reactor core and the limiting design basis transients and accidents are assumed to occur.
In MODES 3, 4, and 5, the consequences of an accident are reduced and the coastdown characteristics of the recirculation loops are not important.
(continued)
PBAPS UNIT 3 B 3.4-5 Revision No.-
Recirculation Loops Operating B 3.4.1 BASES THIS PAGE LEFT BLANK INTENTIONALLY (The contents of this page have been deleted)
PBAPS UNIT 3 B 3.4-6 Revision No.
Recirculation Loops Operating B 3.4.1 BASES ACTIONS (continued)
A-A With the requirements of the LCO not met, the recirculation loops must be restored to operation with matched flows within 24 hours1 days <br />0.143 weeks <br />0.0329 months <br />. A recirculation loop is considered not in operation when the pump in that loop is idle or when the mismatch between total jet pump flows of the two loops is greater than required limits. The loop with the lower flow must be considered not in operation. Should a LOCA occur with one recirculation loop not in operation, the core flow coastdown and resultant core response may not be bounded by the LOCA analyses. Therefore, only a limited time is allowed to restore the inoperable loop to operating status.
Alternatively, if the single loop requirements of the LCO are applied to operating limits and RPS setpoints, operation with only one recirculation loop would satisfy the requirements of the LCO and the initial conditions of the accident sequence.
The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time is based on the low probability of an accident occurring during this time period, on a reasonable time to complete the Required Action, and on frequent core monitoring by operators allowing abrupt changes in core flow conditions to be quickly detected.
ItUll LI IIUtUJ PBAPS UNIT 3 B 3.4-7 Revision No..
i e Recirculation Loops Operating B 3.4.1 BASES ACTIONS AA1 (continued)
This Required Action does not require tripping the recirculation pump in the lowest flow loop when the mismatch between total jet pump flows of the two loops is greater than the required limits. However, in cases where large flow mismatches occur, low flow or reverse flow can occur in the low flow loop jet pumps, causing vibration of the jet pumps. If zero or reverse flow is detected, the condition should be alleviated by changing pump speeds to re-establish forward flow or by tripping the pump.
BI With no recirculation loops in operation or the Required Action and associated Completion Time of Condition A not met, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to MODE 3 within 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br />. In this condition, the recirculation loops are not required to be operating because of the reduced severity of DBAs and minimal dependence on the recirculation loop coastdown characteristics. The allowed Completion Time of 12 hours0.5 days <br />0.0714 weeks <br />0.0164 months <br /> is reasonable, based on operating experience, to reach MODE 3 from full power conditions in an orderly manner and without challenging plant systems.
(continued)
PBAPS UNIT 3 B 3.4-8 Revision No.
I Recirculation Loops Operating B 3.4.1 BASES SURVEILLANCE 5R 3.4.1.1 REQUIREMENTS This SR ensures the recirculation loops are within the allowable limits for mismatch. At low core flow (i.e.,
< 71.75 X 10ilbm/hr), the MCPR requirements provide larger margins to the fuel cladding integrity Safety Limit such that the potential adverse effect of early boiling transition during a LOCA is reduced. A larger flow mismatch can therefore be allowed when core flow is < 71.75 X 105 ibm/hr. The recirculation loop jet pump flow, as used in this Surveillance, is the summation of the flows from all of the jet pumps associated with a single recirculation loop.
The mismatch is measured in terms of core flow. (Rated core flow is 102.5 X 101 lbm/hr. The first limit is based on mismatch
- 10% of rated core flow when operating at < 70% of rated core flow. The second limit is based on mismatch s 5%
of rated core flow when operating at 2 70% of rated core flow.) If the flow mismatch exceeds the specified limits, the loop with the lower flow is considered not in operation.
The SR is not required when both loops are not in operation since the mismatch limits are meaningless during single loop or natural circulation operation. The Surveillance must be performed within 24 hours1 days <br />0.143 weeks <br />0.0329 months <br /> after both loops are in operation.
The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Frequency is consistent with the Surveillance Frequency for jet pump OPERABILITY verification and has been shown by operating experience to be adequate to detect off normal jet pump loop flows in a timely manner.
-(connti nuedi) I PBAPS UNIT 3 B 3.4-9 Revision No.
Recirculation Loops Operating B 3.4.1 BASES REFERENCES 1. UFSAR, Section 14.6.3.
- 2. NEDC-32163P, "PBAPS Units 2 and 3 SAFER/GESTR-LOCA Loss-of-Coolant Accident Analysis," January 1993.
- 3. NEDC-32162P, "Maximum Extended Load Line Limit and ARTS Improvement Program Analyses for Peach Bottom Atomic Power Station Unit 2 and 3," Revision 1, February 1993.
- 4. NEDC-32427P, "Peach Bottom Atomic Power Station Unit 3 Cycle 10 ARTS Thermal Limits Analyses," December 1994.
- 5. NEDO-24229-1, "PBAPS Units 2 and .3Single-Loop Operation," May 1980.
- 6. NEDC-33064P, "Safety Analysis Report for Peach Bottom Atomic Power Station Units 2 & 3 Thermal Power Optimization," May 2002.
PBAPS UNIT 3 B 3.4-10 Revision No. >
Reporting Requirements 5.6 5.6 Reporting Requirements (continued) 5.6.5 CORE OPERATING LIMITS REPORT (COLR)
- a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload cycle, and shall be documented in the COLR for the following:
- 1. The Average Planar Linear Heat Generation Rate for Specification 3.2.1;
- 2. The Minimum Critical Power Ratio for Specifications 3.2.2 and 3.3.2.1;
- 3. The Linear Heat Generation Rate for Specification 3.2.3;
- 4. The Control Rod Block Instrumentation for Specification 3.3.2.1; and
- 5. The Oscillation Power Range Monitor (OPRM)
Instrumentation for Specification 3.3.1.1.
- b. The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:
- 1. NEDE-24011-P-A, "General Electric Standard Application for Reactor Fuel" (latest approved version as specified in the COLR);
- 2. NEDC-32162P, "Maximum Extended Load Line Limit and ARTS Improvement Program Analyses for Peach Bottom Atomic Power Station Units 2 and 3," Revision 2, March, 1995;
- 3. PECo-FMS-0001-A, "Steady-State Thermal Hydraulic Analysis of Peach Bottom Units 2 and 3 using the FIBWR Computer Code";
- 4. PECo-FMS-0002-A, "Method for Calculating Transient Critical Power Ratios for Boiling Water Reactors (RETRAN-TCPPECo)"; .
- 5. PECo-FMS-0003-A, "Steady-State Fuel Performance Methods Report";
\ -- U, v - -. - -I PBAPS UNIT 3 5.0-21 Amendment No.225, 233, 254
Reporting Requirements 5.6 5.6 Reporting Requirements 5.6.5 CORE OPERATING LIMITS REPORT (COLR) (continued)
- 7. PECo-FMS-0005-A, "Methods for Performing BWR Steady-State Reactor Physics Analysis";
- 8. PECo-FMS-0006-A, 'Methods for Performing BWR Reload Safety Evaluations"; and
- 9. NEDO-32465-A, "Reactor Stability Detect and Suppress Solutions Licensing Basis Methodology And Reload Applications," August 1996.
- c. The core operating limits shall be determined such that all applicable limits (e.g., fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.
- d. The COLR, including any midcycle revisions or supplements, shall be provided upon issuance for each reload cycle to the NRC.
5.6.6 Post Accident Monitoring (PAM) Instrumentation Report When a report is required by Condition B or F of LCO 3.3.3.1,
'Post Accident Monitoring (PAM) Instrumentation," a report shall be submitted within the following 14 days. The report shall outline the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the Function to OPERABLE status.
P.BAPS UNIT 3 5.0-22 Amendment No.G, 4+9. 251