ML18033A810
| ML18033A810 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 06/20/1989 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML18033A808 | List: |
| References | |
| NUDOCS 8906280103 | |
| Download: ML18033A810 (38) | |
Text
ENCLOSURE 1 PROPOSED TECNNICAL SPECIFICATIONS REVISIONS BROGANS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3 (TVA BFN TS 271) 89062 OCK 05000259 80103 890620 PDR ADO PDC P
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a particular unit and the end of the next subsequent refueling outage for the same unit.
R.
Refue in Outa e Refueling outage is the period of time between the shutdown of the unit prior to a refueling and the startup of the unit after that refueling.
For the purpose of designating frequency of testing and surveillance, a refueling outage shall mean a regularly scheduled outage;
- however, where such outages occur within 8 months of the completion of the previous refueling outage, the required surveillance testing need not be performed until the next regularly scheduled outage.
S.
CORE ALTERATIO The addition, removal, relocation, or movement of fuel, sources, in-core instruments, or reactivity controls within the reactor pressure vessel with the head removed and fuel in the vessel.
Normal movement of in-core instrumentation and the traversing in-core probe is not defined as a Core Alteration.
Suspension of Core Alterations shall not preclude completion of the movement of a component to a safe conservative position.
T.
Reacto Vessel Pressure Unless otherwise indicated, reactor vessel pressures listed in the Technical 'Specifications are those measured by the reactor vessel steam space detectors.
U.
ermal Parameters l.
inimum C
tica Power Ratio MCPR Minimum Critical Power Ratio (MCPR) is the value of the critical power ratio associated with the most limiting assembly in the reactor core.
Critical Power Ratio (CPR) is the ratio of that power in a fuel assembly, which is calculated to cause some point in the assembly to -experience boiling transition, to the actual assembly operating power.
2.
Transition Boilin Transition boiling means the boiling regime between nucleate and film boiling.
Transition boiling is the regime in which both nucleate and film boiling occur intermittently with neither type being completely stable.
3.
Core Maximum Fraction of Limitin Power Densit CMFLPD The highest ratio, for all fuel types in the core, of the maximum fuel rod power density (kW/ft) for a given fuel type to the limiting fuel rod power density (kW/ft) for that fuel type.
4.
Avera e Planar Linear Heat Generation Rate APLHGR The Average Planar Heat Generation Rate is applicable to a specific planar height and is equ 1 to the sum of the linear heat generation rates for all the fuel iods in the specified bundle at the specified height divided by the number of fuel rods in the fuel bundle.
BFN Unit 1 1.0-7
4 1
'LIMITING CORE ALTERATIO CONDITIONS FOR OPERATION 3.10.A.
Re ue nte locks
'i SURVEILLANCE REQUIREMENTS 4.10.A.
Refue in nter ocks 7 ~
Any number of control rods may be withdrawn or removed from the reactor core providing the following conditions are satisfied:
a.
The reactor mode switch is locked in the REFUEL position.
The refueling interlock which prevents more than one control rod from being withdrawn may be bypassed on a withdrawn control rod after the fuel assemblies in the =ell containing (controlled by) that control rod have been removed from the reactor core.
All other refueling interlocks shall be OPERABLE.
7.
With the mode selection switch in the REFUEL or SHUTDOWN mode, no more than one control rod may be withdrawn without first removing fuel from the cell except as specified in 4.10.A.6.
Any number of rods may be withdrawn once verified by two licensed operators that the fuel has been removed from each cell.
B.
Core Monito in B.
Co e Monitorin 1.
During core alterations, except as specified in 3.10.B.2, two SRMs (FLCs) shall be
- OPERABLE, one in and one adjacent to any quadrant where fuel or control rods are being moved.
For an SRY. (FLC) to be considered
- OPERABLE, the following shall be satisfied:
Prior to making any alterations to the core the SRMs (FLCs) shall'e functionally tested and checked for neutron response.
Thereafter, while required to be OPERABLE, the SRMs will be checked daily for response.
a.
The SRM shall be inserted to the normal operating level.
(Use of special
- moveable, dunking type detectors during initial fuel loading BFN Unit 1 3.10/4.10-4
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i 0 4 0
CORE A
1
'LIMITING CONDITIONS FOR OPERATION
~
"'URVEILLANCE REQUIREMENTS 3.10.B.
Core Monitorin 3.10.B.l.a.
(Cont'd) and major core alterations in place of normal detectors is permissible as long as the detector is connected to the normal SRM circuit.)
b.
Mhen one or more fuel assemblies are in the
minimum indicated reading of 3 cps while monitoring the loaded assembly (assemblies) with all rods fully inserted in the core.
BFN Unit 1 3.10/4.10-5
1 4
CORE A
LIMITING CONDITIONS FOR OPERATION 3.10.B.
Core Monitorin SURVEILLANCE REQUIREMENTS 4.10.B Core Monitorin 2.
During a complete core
- removal, the SRMs shall have an initial minimum count rate of cps prior to fuel removal.
With all rods fully inserted and rendered electrically disarmed and inoperable, once the SRM count rate decreases below 3 cps, the SRM will no longer be required to be OPERABLE during fuel removal.
Individual control rods outside the periphery of the then existing fuel matrix may be electrically armed and moved for maintenance after all fuel in the cell containing (controlled by) that control rod have been removed from the reactor core.
BFN Unit 1 3.10/4.10-6
.4 REACTI RO
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LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.3.C.
Scram Insertion imes 4.3.C.
Scram Insertion Times 2.
The average of the scram insert-tion times for the three fastest operable control rods of all groups of four control rods in a two-by-two array shall be no greater. than:
5 20 50 90 0.398 0.954 2.120 3.800
% Inserted From Avg. Scram Insert-Full Withdra tion es sec 2.
At 16-week intervals, 10%
of the operable control rod drives shall be scram-timed above 800 psig.
Whenever such scram time measurements are made, an evaluation shall be made to provide reasonable assurance that proper control rod drive performance is being maintained.
3.
The maximum scram insertion time for 90% insertion of any operable control rod shall not exceed 7.00 seconds.
D.
Reactivit Anomal es D.
Reactivit Anomalies The reactivity equivalent of the difference between the actual critical rod configuration and the expected configuration during power operation shall not exceed 1% Wk.
If this limit is exceeded, the reactor will be placed in the SHUTDOWN CONDITION until the cause has been determined and corrective actions have been taken as appropriate.
During the startup test program and startup following refueling outages, the critical rod configurations will be compared to the expected configurations at selected operating conditions.
These comparisons will be used as base data for reactivity monitoring during subsequent power operation throughout the fuel cycle.
At specific power operating conditions, the critical rod configuration will be compared to the configuration expected based upon appropriately corrected past data.
This comparison will be made at least every full power month.
BFN Unit 1 3.3/4.3-11
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3.10 BASES (Cont'd)
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~ I B.
Core Mo itorin The SRMs are provided to monitor the core during periods of station shutdown and to guide the operator during refueling operations and station startup.
Requiring two operable SRMs (FLCs) one in and one adjacent to any core quadrant where fuel or control rods are being moved assures adequate monitoring of that quadrant during such alterations.
The requirement of three counts per second provides assurance that neutron flux is being monitored and ensures that startup is conducted only if the source range flux level is above the rqinimum assumed in the control rod drop accident.
During a full core reload, the fuel will be loaded in control cells that are continuous to previously loaded control cells.
This provided coupling of the loaded fuel matrix which is being monitored by the SRMs (FLCs).
Under the special condition of removing the full core with all control rods inserted and electrically disarmed, it is permissible to allow SRM count rate to decrease below three counts per second.
All fuel moves during core unloading will reduce reactivity. It is expected that the SRMs will drop below three counts per second before all of the fuel is unloaded.
Since there will be no reactivity additions during this
- period, the low number of counts will not present a hazard.
When sufficient fuel has been removed to the spent fuel storage pool to drop the SRM count rate below 3 cps, SRMs will no longer be required to be operable.
Requiring the SRMs to be functionally tested prior to fuel removal assures that the SRMs will be operable at the start of fuel removal.
The daily response cheek of the SRMs ensures their continued operability until the count rate diminishes due to fuel removal.
Control rods in cells from which all fuel has been removed and which are outside the periphery of the then existing.fuel matrix may be armed.
electrically and moved for maintenance purposes during full core removal, provided all rods that control fuel are fully inser'ted and electrically disarmed.
REFERENCES 1.
Neutron Monitoring System (BFNP FSAR Subsection 7.5) 2.
- Morgan, W. R., "In-Core Neutron Monitoring System for General Electric Boiling Water Reactors,"
General Electric Company, Atomic Power Equipment Department, November 1968, revised April 1969 (APED-5706)
BFN Unit 1 3.10/4.10-13
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IT 0 S (Cont'd)
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for a particular unit and the end of the next subsequent refueling outage for the same unit.
R.
Refue n
Outa e Refueling outage is the period of time between the shutdown of the unit prior to a refueling and the startup of the unit after that refueling.
For the purpose of designating frequency of testing and surveillance, a refueling outage shall mean a
regularly scheduled outage;
- however, where such outages occur within 8 months of the completion of the previous refueling outage, the required surveillance testing need not be performed until the next regularly scheduled outage.
S.
CORE ALTERATION The addition, removal, relocation, or movement of fuel, sources, incore instruments, or reactivity controls within the reactor pressure vessel with the head removed and fuel in the vessel.
Normal movement of in-core instrumentation and the traversing in-core probe, is not defined as a Core Alteration.
Suspension of Core Alterations shall not preclude completion of the movement of a component to a safe conservative position.
Reactor Vessel Pressure Unless otherwise indicated, reactor vessel pressures listed in the Technical Specifications are those measured by the reactor vessel steam space detectors.
U.
al Parameters 1.
Minimum C itical Power Ratio MCPR Minimum Critical Power Ratio (MCPR) is the value of the critical power ratio associated with the most=limiting assembly in the reactor core.
Critical Power Ratio (CPR) is the ratio of that power in a fuel assembly, which is calculated to cause some point in the assembly to experience boilinp transition, to the actual assembly operating power.
2.
Transition Boilin Transition'oiling means the boiling regime between nucleate and film boiling.
Transition boiling is the regime in which both nucleate and film boiling occur intermittently with neither type being completely stable.
3.
Core Maximum Fraction of Limitin Power Densit C
PD The highest ratio, for all fuel types in the core, of the maximum fuel rod power density (kW/ft) for a given fuel type to the
,limiting fuel rod power density (kW/ft) for that fuel type.
4.
Avera e Planar Liaear Heat Generation Rate APLHGR The Average Planar Heat Generation Rate is applicable to a specific planar height and is equal to the sum of the linear heat generation rates for all the fuel rods in the specified bundle at the specified height divided by the number of fuel rods in the fuel bundle.
BFN Unit 2 1.0-7
/4.1 COR A
LIMITING CONDITIONS FOR OPERATION 3.10.A.
Refuel n Inter ocks SURVEILLANCE REQUIREMENTS 4.10.A.
Refuelin nte ocks 7.
Any number of control rods may be withdrawn or removed from the reactor core providing the following conditions are satisfied:
1 a.
The reactor mode switch is locked in the REFUEL position.
The refueling interlock which prevents more than one control rod from being withdrawn may be bypassed on a withdrawn control rod after the fuel assemblies in the cell containing (controlled by) that control rod have been removed from the reactor core.
All other refueling interlocks shall be OPERABLE.
7.
With the mode selection switch in the REFUEL or SHUTDOWN mode, no more than one control rod may be withdrawn without first removing fuel from the cell except as specified in 4.10.A.6.
Any number of rods may be withdrawn once verified by two licensed operators that the fuel has been removed from each cell.
B.
Core Monitorin 1.
During core alterations, except as specified in 3.10.B.2, two SRMs (FLCs) shall be
- OPERABLE, one in and one adjacent to any quadrant where fuel or control rods are being moved.
For an SRM (FLC) to be considered
- OPERABLE, the following shall be satisfied:
Prior to making any alterations to the core the SRMs (FLCs) shall be functionally tested and checked for neutron response.
There after, while required to be OPERABLE, the SRMs will be checked daily for response.
a ~
The SRM shall be inserted to the normal operating level.
(Use of special
- moveable, dunking type detectors during initial fuel loading BFN Unit 2 3.10/4.10-4
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4 CORE ALTE TIO LIMITING CONDITIONS FOR OPERATION 0'URVEILLANCEREQUIREMENTS 3.10.B.
Core Monito in 3.10.B.l.a.
(Cont'd) and major core alterations in place of normal detectors is permissible as long as the detector is connected to the normal SRM circuit.)
b.
Shen one or more fuel assemblies are in the
minimum indicated reading of 3 cps while monitoring the loaded assembly (assemblies) with all rods fully inserted in the core.
BFN Unit 2 3.10/4.10-5
4 10 CORE ALTE TIO I
LIMITING CONDITIONS FOR OPERATION 0'URVEILLANCEREQUIREMENTS 4.10.B Core Monitorin 2.
During a complete core
- removal, the SRMs shall have an initial minimum count rate of 3 cps prior to fuel removal.
With all rods fully inserted and rendered electrically disarmed and inoperable.
Once the SRM count rate decreases below 3 cps, the SRMs will no longer be required to be OPERABLE during fuel removal.
Individual control rods outside the periphery of the then existing fuel matrix may be electrically armed and moved for maintenance after all fuel in the cell containing (controlled by) that control rod have been remov.d from the reactor core.
BFN Unit 2 3.10/4.10-6
P,
~ ~4 REACT V Y C LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.3.C.
Scram Insertion Times 4.3.C.
Scram Insertion Times
/ Inserted From Avg. Scram Inser-Full Withdrawn tion Times sec 5
20 50 90 0.398 0.954 2.120 3.800 2.
The average of the scram inser-tion times for the three fastest OPERABLE control rods of all groups of four control rods in a two-by-two array shall be no greater than:
- 2. At 16-week intervals, 10/
of the OPERABLE control rod drives shall be scram-timed above 800 psig.
Whenever such scram time measurements are made, an evaluation shall be made to provide reasonable assurance that proper control rod drive performance is being maintained.
3.
The maximum scram insertion time for 90/ insertion of any OPERABLE control rod shall not exceed 7.00 seconds.
D.
Reactivit A omalies D.
Reactivit Anomalies The'eactivity equivalent of the difference between the actual critical rod configuration and the expected configuration during power operation shall not exceed 1% Wk.
If this limit is exceeded, the reactor will be placed in SHUTDOWN CONDITION until the cause has been determined
- and, corrective actions have
'oeen taken as appropriate.
During the STARTUP test program and STARTUP following refueling outages, the critical rod configurations will be compared to the expected configurations at selected operating conditions.
These comparisons will be used as base data for reactivity monitoring during subsequent power operation throughout the fuel cycle.
At specific power operating conditions, the critical rod configuration will be compared to the configuration expected based upon appropriately corrected past'ata.
This comparison will be made at least every full power month.
BFN Unit 2 3.3/4.3-11
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3.10 BASES (Cont'd)
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B.
Core Mo torin
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The SRMs are provided to monitor the core during periods of station shutdown and to guide the operator during refueling operations and station startup.
Requiring two operable SRMs (FLCs) one in and one adjacent to any core quadrant where fuel or control rods are being moved assures adequate monitoring of that quadrant during such alterations.
The requirement of three counts per second provides assurance that neutron flux is being monitored and ensures that startup is conducted only if the source range flux level is above the minimum assumed in the control rod drop accident.
During a full core reload, the fuel will be loaded in control cells that are contiguous to previously loaded control cells.
This provides coupling of the loaded fuel matrix which is being monitored by the SRMs (FLCs).
During a full core reload SRM/FLC (Fuel Loading Chamber) operability will be verified using a portable external source at least once every eight hours until sufficient fuel has been loaded to maintain three counts per second.
A large number of fuel assemblies will not be required to maintain three counts per second.
This increased surveillance rate assures proper detector operability until that time.
I Under the special condition of removing the full core with all control rods inserted and electrically disarmed, it is permissible to allow SRM count rate to decrease below three counts per second.
All fuel moves during core unloading will reduce reactivity. lt is expected that the SRMs will drop below three counts per second before all of the fuel is unloaded.
Since there will be no reactivity additions during this
- period, the low number of counts will not present a hazard.
When sufficient fuel has been removed to the spent fuel storage pool to drop the SRM count rate below 3 cps, SRMs will no longer be required to be operable.
Requiring the SRMs to be functionally tested prior to fuel removal assures that the SRMs will be operable at the start of fuel removal.
The daily response check of the SRMs ensures their continued operability until the count;.'ate diminishes due to fuel removal.
Control rods in cells from which all fuel has been removed and which are outside the periphery of the then existing fuel matrix may be armed electrically and moved for maintenance purposes during full core removal, provided all rods that control fuel are fully inserted and electrically disarmed.
REFERENCES I
I 1.
Neutron Monitoring System (BFNP FSAR Subsection 7.5) 2.
- Morgan, W. R., "ln-Core Neutron Monitoring System for General Electric Boiling Water Reactors,"
General Electric Company, Atomic Power Equipment Department, November 1968, revised April 1969 (APED-5706)
BFN Unit 2 3.10/4.10-13
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ZONS (Cont'd for a particular unit and the end of the next subsequent refueling outage for the same unit.
R.
Re ue n
Outa e Refueling outage is the period of time between the shutdown of the unit prior to a refueling and the startup of the unit after that refueling.
For the purpose of designating frequency of testing and surveillance, a refueling outage shall mean a
regularly scheduled outage;
- however, where such outages occur within 8 months of the completion of the previous refueling outage, the required surveillance testing need not be performed until the next regularly scheduled outage.
S.
CORE ALTERAT 0 The addition, removal, relocation, or movement of fuel, sources, incore instruments, or reactivity controls within the reactor pressure vessel with the head removed and fuel in the vessel.
Normal movement of in-core instrumentation and the traversing in-core probe is not defined as a Core Alteration.
Suspension of Core Alterations shall not preclude completion of the movement of a component to a safe conservative position.
Reacto Vesse ressura Unless otherwise indicated, reactor vessel pressures listed. in the Technical'Specifications are those measured by the reactor vessel steam space detectors.
U.
Therma Parameters 1.
Minim Critica Powe Ratio MCPR Minimum Critical Power Ratio (MCPR) is the value of the critical power ratio associated with the most limiting assembly in the reactor core.
Critical Power Ratio (CPR) is the ratio of that power in a fuel assembly, which is calculated to cause
'some point in the assem'eely to experience boiling transition, to the actual assembly operating
'ower.
2.
Transition Boilin Transition boiling means the boiling regime between nucleate and film boiling.
Transition boiling is the regime in which both nucleate and film boiling occur intermittently with neither type being completely stabl'e.
3.
Core Maximum F action of Limitin Powe Densit CMFLPD The highest ratio, for all fuel types in the core, of the maximum fuel rod power density (kW/ft) for a given fuel type to the
,. limiting fuel rod power density (kW/ft) for that fuel type.
4.
Avera e Planar Linear Heat Generation Rate APLHGR The Average Planar Heat Generation Rate is applicable to a specific planar height and is equal to the sum of the linear heat generation rates for all the fuel rods in the specified bundle at the specified height divided by the number of fuel rods in the fuel bundle.
BFN Unit 3 1.0-7
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LIMITING CORE AL 0
CONDITIONS FOR OPERATION 3.10.A.
Refue in nterlocks SURVEILLANCE REQUIREMENTS 4.10.A.
Re uelin Interlocks 7 ~
Any number of control rods may be withdrawn or removed from the reactor core providing the following conditions are satisfied:
a.
The reactor mode switch is locked in the REFUEL position.
The refueling interlock which prevents more than one control rod from being withdrawn may be bypassed on a withdrawn control rod after the fuel assemblies in the cell containing (controlled by) that control rod have been removed from the reactor core.
All other refueling interlocks shall be OPERABLE.
7 ~
With the mode selector switch in the REFUEL or SHUTDOWN mode, no more than one control rod may be withdrawn without first removing fuel from the cell except as specified in 4.10.A.6.
Any number of rods may be withdrawn once verified by two licensed operators that the fuel has been removed from each cell.
B.
Core Monitorin 1.
During core alterations, except as specified in 3.10.B.2, two SRMs (FLCs) shall be OPERABLE, one in and one adjacent to any quadrant where fuel or control rods are being moved.
For an SRM (FLC) to be considered OPERABLE, the following shall be satisfied:
Prior to making any alterations to the core the SRMs (FLCs) sha11. be functionally tested and checked for neutron response.
Thereafter, while required to be OPERABLE, the SRMs will be checked daily for response.
a ~
The SRM shall be inserted to the normal operating level.
(Use of special moveable, dunking type detectors during initia3 fuel loading BFN Unit 3 3.10/4.10-4
$.1 4.10 CORE A
'LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.10.B.l.a.
(Cont'd) and major core alterations in place of normal detectors is permissible as long as the detector is connected to the normal SRM circuit.)
b.
When one or more fuel assemblies are in the
minimum indicated reading of 3 cps while monitoring the loaded assembly (assemblies) with all rods fully inserted in the core.
BFN Unit 3 3.10/4.10-5
t 1
4 1
CORE ALT
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LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.10.B.
Core Monitori 4.10.B Core Monitorin 2.
During a complete core
- removal, the SRMs shall have an initial minimum count rate of 3 cps prior to fuel removal.
With all rods fully inserted and rendered electrically disarmed and inoperable.
Once the SRM count rate decreases below 3 cps, the SRMs will no longer be required to be OPERABLE during fuel removal.
Individual control rods outside the periphery of the then existing fuel matrix may be electrically armed and moved for maintenance after all fuel in the cell containing (controlled by) that control rod have been removed from the reactor core.
BFN Unit 3 3.10/4.10-6
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4 REACTIVITY CONTROL LIMITING CONDITIONS FOR OPERATION 3.3.C.
Scram Inse tio mes SURVEILLANCE REQUIREMENTS 4.3.C.
Scr Insertion Times
% Inserted From Full Withdrawn Avg. Scram Inser-tion es sec 5
20 50 90 0.398 0.954 2.120 3.800 2.
The average of the scram inser-tion times for the three fastest OPERABLE control rods of all groups of four control rods in a two-by-two array shall be no greater than:
- 2. At 16-week intervals, 10%
of the OPERABLE control rod drives shall be scram-timed above 800 psig.
Whenever such scram time measurements are made, an evaluation shall be made to provide reasonable assurance that proper control rod drive performance is being maintained.
3.
The maximum scram insertion time for 90% insertion of any OPERABLE control rod shall not exceed 7.00 seconds.
D.
Reactivit nomal es D.
Reactivit Anomal es The reactivity equivalent of the difference between the actual critical rod configuration and the expected configuration during power operation shall not exceed-1%
Wk.
If this limit is exceeded, the reactor will be placed in the SHUTDOWN CONDITION until the cause has been determined and corrective actions have been taken as appropriate.
During the startup test program and startup following refueling outages, the critical rod configurations will be compared to the expected configurations at selected operating conditions.
These comparisons will be used as base data for reactivity monitoring during subsequent power operation throughout the fuel cycle.
At specific power operating conditions, the critical rod configuration will be compared to the configuration expected based upon appropriately corrected past data.
This comparison will be made at least every full power month.
BFN Unit 3 3.3/4.3-11
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3.10 DEBASES (Cont'd)
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~
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The SRMs are provided to monitor the core during periods of station shutdown and to guide the operator during refueling operations and station startup.
Requiring two OPERABLE SRMs (FLCs) one in and one
- adjacent, to any core quadrant where fuel or control rods are being moved assures adequate monitoring of that quadrant during such alterations.
The requirement of three counts per second.provides assurance that neutron flux is being monitored and insures that startup is conducted only if the source range flux level is above the minimum assumed in the control rod drop accident.
During a full core reload, the fuel will be loaded in control cells that are contiguous to previously loaded control cells.
This provides coupling of the loaded fuel'atrix which is being monitored by the SRMs (FLCs).
Under the special condition of removing the full core with all control rods inserted and electrically disarmed, it is permissible to allow SRM count rate to decrease below three counts per second.
All fuel moves during core unloading will reduce reactivity. It is expected that the SRMs will drop below three counts per second before all of the fuel is unloaded.
Since there will be no reactivity additions during this
- period, the low number of counts will not present a hazard.
When sufficient fidel has been removed to the spent fuel storage pool to drop the SRM count rate below 3 cps, SRMs will no longer be required to be operable.
Requiring the SRMs to be functionally tested prior to fuel removal assures that the SRMs will be OPERABLE at the start of fuel removal.
The daily response check of the SRMs ensures their continued operability until the count rate diminishes due to fuel removal.
Control rods in cells from which all fuel has been removed may be armed electrically and moved for maintenance purposes during full core removal, provided all rods that control fuel are fully inserted and electrically disarmed.
References 1.
Neutron Monitoring System (BFNP FSAR Subsection 7.5) 2.
- Morgan, W. R., "In-Core Neutron Monitoring System for General Electric Boiling Water Reactors,"
General Electric Company, Atomic Power Equipment Department, November 1968, revised Apri'1 1969 (APED-5706)
BFN Unit 3 3.10/4.10-13 l
c
Enclosure 2
0'escription and Justification Browns Ferry Nuclear Plant (BFN)
REASON FOR CHANGE BFN units 1, 2, and 3 technical specifications (TS), AORS, F 10.B, and 3 '0 AC are being revised.
The main purpose of this change is to delete TS 3'0 '.l.b.2 and 3 '0.Bable 3 which currently allows reactivity additions without continuous core monitoring and to clarify requirements for fuli core offloads.
The other changes associated with this proposed amendment are to correct other deficiencies identified with these sections.
These are interim changes resulting from agreements between NRC and TVA during an Enforcement Conference earlier this year.
There is currently no industry standard practice for neutron monitoring during core alterations.
GE is currently working with EPRI on a program to evaluate reactivity controls during refueling and expects to complete generic recommendations for use by the utilities in early 1990 'VAwill evaluate these generic recommendations when they become available to the industry.
Core loading is not anticipated with these proposed interim TS
- changes, however, the proposed TSs will support a core loading if needed.
BACKGROUND The initial BFN TS (3'0') required that 2 Source Range Monitors (SRMs) or Fuel Loading Chambers (FLCs) have at least 3
CPS during core alterations.
On June 2, 1975, TVA submitted a proposed TS change to allow a full core unload with the SRMs (FLCs) decreasing below 3 GPSS'his change was approved by NRC letter dated June 13, 1975
'VA proposed TS change (TVA BFNP TS 126) was submitted on July 20, 1979 for TS 3'0 '.l.b.2 which allowed fuel to be loaded with less than 3
CPS on the SRMs (FLCs) provided the SRM response was checked every eight hours and.the fuel was loaded in a spiral pattern.
This change was approved by NRC letter dated October ll, 1979
'n November 7, 1983, TVA submitted proposed TS change, TVA BFNP TS 193, to NRC for TS F 10.B.l.b.3 which added the fl'exibilityof first loading four irradiated fuel assemblies around each SRM to attain a 3 CPS and then loading in a spiral sequence from the center of the core.
This provides continuously observable detector response of the SRMs.
However, both TS 3'0 '.l.b.2 and 3.10 '.l.b.3 do not provide continuous monitoring of reactivity additions to the core until a sufficient number of fuel bundles have been loaded to overcome the neutron attenuation caused by geometry effects.
This proposed change was approved by NRC letter dated June 25, 1984
'n January
- 1989, BFN unit 2, cycle 6 fuel loading was initiated using existing TS 3'0 '.a.b.2 but stopped after loading 74 fuel assemblies'ue to inadequate core monitoring during the fuel loading.
Evaluation of the BFN TS revealed the need for changes to the TS and procedures to ensure that continuous monitoring of core alterations which could add reactivity to the core was provided.
TVA committed to revise the TS and Final Safety Analysis Report (FSAR) to ensure consistency in the licensing basis and adequate core monitoring for future reloading in TVA response to NRC Inspection Report Numbers 50-259/89-04, 50-260/89-04, and 50-296/89-04 for BFN dated March 1, 1989.
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'DESCRIPTION AND JUSTIFICATION FOR THE PROPOSED CHANGE l.
EXISTING DEFINITION 1.0.S CURRENTLY READS:
CORE ALTERATION The addition, removal, relocation, or movement of fuel,
- sources, in-core instruments, or reactivity controls within the reactor pressure vessel with the head removed and fuel in the vessel.
Normal control rod movement with the control rod drive hydraulic system is not defined as a Core Alteration.
Normal movement of in-core instrumentation and the traversing in-core PROPOSED CHANGE TO EXISTING DEFINITION 1.0.S WOULD READ:
CORE ALTERATION The addition, removal, relocation, or movement of fuel,
- sources, in-core instruments, or reactivity controls within the reactor pressure vessel with the head removed and fuel in the vessel.
Normal movement of the in-core instrumentation and the transversing in-core
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JUSTIFICATION FOR PROPOSED CHANGE TO 1.0.S This change deletes the sentence "Normal control rod movement with the control rod drive hydraulic system is not defined as a Core Alteration."
The current TS definition of core alteration encompasses all the activities which could result in increasing reactivity except for control rod withdrawal.
Since the objective stated in TS 3.10 is to. prevent criticality during refueling, anything that could potentially result in increasing the chances of an inadvertent criticality including control rod withdrawal should require similar controls and restrictions.
Therefore, TS equipment operability requirements during core alterations should also apply for normal control rod withdrawal with the reactor vessel head removed and fuel in the vessel.
In addition, this change is consistent with GE BWR Standard Technical Specifications NUREG-0123.
2.
EXISTING TS 3.10.B.l CURRENTLY READS:
During core alterations, except as in 3.10.B.2, two SRMs 'shall be OPERABLE, in or adjacent to any quadrant where fuel or control rods PROPOSED CHANGE TO EXISTING TS 3.10.B.l TO READ:
During core alterations, except as "specified" in 3.10.B.2, two SRMs (FLCs) "one" in "and one" adjacent to any quadrant where fuel or control rods are being moved.
JUSTIFICATION FOR PROPOSED CHANGE TO TS'.10.B.1 The proposed TS change will require that a minimum of two SRMs are opera/le during core alterations with one SRM (FLC) in the quadrant where the core alteration is being made and one SRM (FLC) operable in an adjacent quadrant.
The current TS require the two operable SRMs to be in or adjacent to any quadrant where core alterations are being made.
This change ensures that a
SRM close to the core alteration is operab1e, This change is more conservative than the existing TS and is also consistent with the guidance provided in the GE Standard Technical Specifications NUREG 0123.
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3.
EXISTING SR 4.10.B CURRENTLY READS:
. Therefore, while required to be OPERABLE, the SRMs will be checked daily for response, except as specified in 3.10.B.l.b.2.
PROPOSED CHANGE TO EXISTING SR 4.10.B.TO READ:
. Therefore, while required to be OPERABLE, the SRMs (FLCs) will be checked daily for response.
JUSTIFICATION FOR PROPOSED CHANGE TO SR 4.10.B This change is being made for consistency.
TS 3.10.B.l.b.2 is being deleted.
For justification see item 5 below.
4.
EXISTING TS 3.10.B.l.b.l (NEW TS NUMBER 3.10.B.l.b)
CURRENTLY READS:
The SRM shall have a minimum of 3 CPS with all rods fully inserted in the core, if on or more fuel assemblies are in the core, or PROPOSED CHANGE TO EXISTING TS 3.10.B.l.b.l (NEW TS NUMBER 3.10.B.l.b)
TO READ:
"When one or more fuel assemblies are in the core, except as specifies in 3.10.B.2, the SRM (FLC) shall have a minimum indicated reading of 3 CPS while monitoring the loaded assembly (assemblies) with all rods fully inserted in the core."
JUSTIFICATION FOR PROPOSED CHANGE TO NEW TS 3.10.B.l.b The change made to this TS is to provide consistency with the referenced TS 3.10.B.2 and to clarify how the SRMs (FLCs) will be used during a reload.
Additional justification is located in the justification section for TS 3.10.B.2 item 6 below.
5.
EXISTING TS 3.10.B.l.b.2 CURRENTLY READS:
During a full core reload where both irradiated and fresh fuel is being
- loaded, SRMs (FLCs) may have a count rate of 3 CPS provided <hat the SRMs are response checked at 1 ast once every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> with. a neutron source until 3 CPS can be maintaine4, and provided also that the core is loaded in a spiral sequence only, or EXISTING TS 3.10.B.l.b.3 CURRENTLY READS:
During full core reload where both irradiated and fresh fuel are being
- loaded, four (4) irradiated.,fuel assemblies will be placed adjacent to each SRM to establish a count rate of 3 CPS, provided each SRM is functionally tested prior to adjacent fuel loading, a neutron response is observed as the adjacent fuel is loaded,"
and the core is loaded in a spiral sequence only after the SRM adjacent fuel loading.
DELETE TS 3.10.B.l.b.2 and 3.10.B.l.b.3
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JUSTIFICATION FOR DELETING TS 3.10.B.l.b.2 AND 3.10.B.l.b.3 The current TS provides two options for performing full core reloads without adequately monitoring the changes in reactivity.
The first-option deleted is TS 3.10.b.l.B.2 which allows the SRM (FLC) count rate to be less than the 3
CPS if the core is loaded in a spiral sequence.
With the spiral loading from the center of the core, the SRMs can be several control cells away from the fuel.
Neutron attenuation prevents the SRMs from responding to an increase in neutron count rate in the core.
Continuous monitoring of reactivity changes is not available until a sufficient number of fuel assemblies is loaded to overcome the neutron attenuation caused by the geometry effects.
The second option deleted is TS 3.10.B.l.b.3 which allows the same spiral loading sequence after placing four irradiated fuel assemblies adjacent to each SRM is responding to neutrons.
However, the same problem exists as allowed by TS 3.10.B.l.b.2 where, due to neutron attenuation, the SRMs would not directly monitor all core, alterations when fuel assemblies are loaded in the center of the core.
These two options for full core reloads are being deleted to prevent the possibility of performing core alterations which add reactivity without being directly monitored by the SRMs at all times.
6.
EXISTING TS 3.10.B.2 CURRENTLY READS:
During a complete core removal, the SRMs shall have an initial minimum count rate of 3 CPS prior to fuel removal, with all rods fully inserted an rendered electrically inoperable.
The count rate will diminish during fuel removal.
Individual control rods outside periphery of the PROPOSED CHANGE TO EXISTING TS 3.10.B.2.
TO READ AS FOLLOWS:
During a complete core removal, the SRMs shall have an initial minimum count rate of 3 CPS prior to fuel removal."
With all rods fully inserted and rendered electrically disarmed and inoperable,"
once the SRM count rate decreases below 3 CPS, the SRMs will no longer be required to be OPERABLE" during fuel removal JUSTIFICATION FOR PROPOSED CHANGE 3.10.B.2 This change will clarify the intent of TS 3.10.B.2 and to ensure no inconsistencies exist within the TS section 3.10.B.
The intent of TS 3.10.B.2 is to allow the SRM count rate to decrease below 3 CPS during the special condition of removing the full core with all control rods inserted and electrically. disarmed.
TS 3.10.B.l provided an exception to the requirement for two operable SRMs fo'r full core offload in accordance with TS 3.10.B.2.
However, existing TS 3.10.B.l.b.l which requires SRMs to have 3
CPS did not specifically make an exception for the full core offload.
In addition, existing TS 3.10.B.2 is not clear in that after requiring an initial minimum SRM count rate of 3 CPS, 'it stated that "the count rate will diminish during fuel removal.":
The wording in t?Se basis more clearly stated the intent of the TS which would allow the SRM count rate to decrease below 3 CPS.
Since this TS applies only to removal of fuel which reduces reactivity with each fuel assembly move and since control rod withdrawal is not possible, there are no core alterations which add reactivity during the core offload.
Since the reactor is subcritical prior to starting the fuel removal, the only core alterations allowed make the reactor more subcritical.
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CHANGE EXISTING TS 3.3.C.2.a (PAGE 3.3/4.3-11)
TO 3.3.C.3.
JUSTIFICATION Existing TS 3.3.A.2.c references TS 3.3.C.3.
The existing BFN TS do not have a TS 3.3.C.3.
The correct reference is TS 3.3.C.2.a.
Changing TS 3.3.C.2.a to 3.3.C.3 not only corrects the reference as stated in existing TS 3.3.A.2.c but it provides numerical consistency,.vithin section 3.3.C.
This change only corrects the TS number and does not change or delete any TS requirements.
Making this change only provides the proper numerical sequence.
8.
REVISE BASES SECTION 3.10.B AS SHOWN IN PROPOSED TS I'USTIFICATION FOR PROPOSED BASES SECTION 3.10.B The Bases Section is being updated to reflect the changes discussed above.
This is to make the Bases Section consistent and provide clarification to the changes made above.
ENCLOSURE 3
DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION BROWS FERRY NUCLEAR PLANT (BFN)
UNITS 1, 2, AND 3 DESCRIPTION OF PROPOSED TS AMENDMENT BFN units 1, 2, and 3 technical specifications (TS), 1.0.S, 3.10.B.,
and 3.10.C are being revised.
The main purpose of this change is to delete TS 3.10.B.l.b.2 and 3.10.B.l.b.3 which currently allows reactivity additions without continuous core monitoring and to clarify requirements for full core offloads.
The other changes associated with this proposed amendment are to correct other deficiencies identified with these sections.
These are interim changes resulting from agreements between NRC and TVA during an Enforcement Conference earlier this year.
There is currently no industry standard practice for neutron monitoring during core alterations.
GE is currently working with EPRI on a program to evaluate reactivity controls during refueling and expects to complete generic recommendations for use by utilities in early 1990.
TVA will evaluate these generic recommendations when they become available to the industry.
Core loading is not anticipated with these proposed interim TS
- changes, however, the proposed TSs will support a core loading if needed.
BASIS FOR PROPOSED NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION NRC has provided standards for determining whether a significant hazards considerations exists as stated in 10CFR50.92(c).
A proposed amendment-to an operating license involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not (1) involve a significant increase in the probability or consequences of an accident previously evaluated, or (2) create the possibility of a new or different kind of accident from an accident previously evaluated, or (3) involve a significant reduction in a margin of safety.
1.
This proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
The design basis accident during core alterations is the dropping of a fuel assembly.
Since these changes increase the monitoring requirements for core alterations and there is no new fuel handling activity introduced that was not previously allowed by the current technical specifications, there is no increase in the probability or consequence of the dropped assembly accident.
These changes do not increase the probability or consequences of a control rod removal error or a fuel assembly insertion error so there is no increased
'robability or consequence of an accidental reactivity insertion or an inadvertent criticality.
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This proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
These TS changes result in improved monitoring requirements during core alterations that would add reactivity.
There are no new activities required during core alterations due to these proposed changes which could introduce any new or different accident.
The deletion of the two options of loading fuel without continuous SRM monitoring will require the use of fuel loading chambers (FLCs) during part of the fuel loading.
FLCs have been used during 13 previous fuel loadings at BFN.
The proposed clarification of the TS allowing the SRM count rate to decrease below 3 cps during the special conditions specified for complete core unloading do not change the intent of the current TS.
Since control rods are inserted and cannot be moved and only fuel moves which remove fuel are made, no core reactivity alteration will be made that would increase reactivity.
All other changes are more conservative than the current TS requirements on core, alterations, including normal control rod movement.
Therefore, the* possibility of a new kind of accident is not created.
3.
This change does not Involve a significant reduction in the margin of safety.
The only margin of safety applicable to fuel loading is the requirement for having a 0.38 percent 6 K shutdown margin.
The proposed changes to not affect shutdown margin however, they are conservative by requiring continuous SRM monitoring during core alterations which could add reactivity and by defining requirements for control rod withdrawal with the vessel head removed to be the same requirements as for core alterations.
-The use of SRMs for core monitoring during core alterations is not taken credit for in any margin of safety as defined in the TS bases.
Since these proposed TS changes are more restrictive, they will not result in the reduction of any margin of safety as defined in the TS bases.
DETERMINATION OF BASIS FOR PROPOSED NO SIGNIFICANT HAZARDS Since the application for amendment involves a proposed change that is encompassed be the criteria-for which no significant hazards consideration exists, TVA has made a proposed determination that the application involves no significant hazards consideration.
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