ML18065A384
| ML18065A384 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 01/05/1996 |
| From: | CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML18065A383 | List: |
| References | |
| NUDOCS 9601160235 | |
| Download: ML18065A384 (5) | |
Text
'sHUTDOWN coo~ (SOC)
Specification 3.1.9.3 One SOC train shall be in operation ~roviding ~ 1000 gpm flow through the reactor core, and at lea~t two of the means of decay heat removal listed below shall be OPERABLE:
- 1.
SOC train A cons,i sting of an OPERABLE SOC pump and an OPERABLE heat flow path to Lake Michigan.
- 2.
SOC train B consisting of an OPERABLE SOC pump and an OPERABLE heat flow path to Lake Michigan.
- 3.
The refueling cavity with water level ~ 647'.
Applicability Specification 3.1.9.3 applies when there is fuel in the reactor, with PCS Temperature is < 200°F and the PCS loops NOT filled.
Exceptions I.
All flow through the reactor core may be intentionally stopped for up to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> provided:
- a.
- b.
- c.
No operations are permitted that would cause reduction of the PCS boron concentration or PCS inventory, and Core outlet temperature stays ~ 200°F, and Two SOC trains are OPERABLE.
- 2.
One or both required SOC trains may be intentionally rendered inoperable for testing or maintenance for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> provided:
Action
- a.
One SOC train is providing flow through the reactor core, and
- b.
Core outlet temperature stays ~ 200°F, and
- c.
The refueling cavity water level is ~ 647'.
- I.
With fewer OPERABLE means of decay heat removal, than required:
- a.
Immediately initiate corrective action to return a second train to OPERABLE status, and
- b.
Maintain PCS temperature as low as practical with available equipment.
- 2.
With less flow through the core than required:
- a.
Immediately suspend all operations involving a reduction in PCS boron concentration, and
- b.
Immediately initiate corrective action to return a train to operation providing flow through the core.
- 9601160235 960105 PDR ADOCK 05000255 p
PDR 3-25j Amendment No. -l&l,
3.1.
3.1.9 Basis 0
PRIMARV COOL~SVSTEM (PCS)
SHUTDOWN COOLIN~
The Shutdown Cooling (SOC) spectfications require a minimum flow be maintained through the reactor core and two methods of decay heat removal to be OPERABLE, in each of three situations, PCS temi:>erature 200°F to 300°F, PCS temperature below 200°F with the loops filled, anCi PCS temperature below 200° F with the l OOJ>S not fi 11 ed.
"Loops Fil led" means the PCS loops are intact, not bloc keCi by dams, and tot a 11 y filled with cool ant.
The requirement to maintain 2810 gpm flow through the reactor core when the PCS loops are filled is based o~ an analysis of potential ~ilution events.
Maintenance of this flow assures that indication of increasing count rate will be available to warn the operator and allow compensating action. The requirement to maintain 1000 gpm flow throu~h the reactor core when the loops are not filled assures mixing of the PCS wh1le allowing flow to be reduced to avoid vortexing in the SOC suction piping.
The 1000 gpm is based on operating expertence, rather on analysis. With flow less than 2810 gpm, Specification 3.10.1 imposes additional requirements for Shutdown Margin and limits charging pump operabil i ty. Maintaining fl ow through the reactor core also allows use of the SOC temperature indication to determine core outlet temperature when the core outlet thermocouples are not in service.
Natural circulation.is adequate for decay heat removal, however it may not provide adequate mixing of the PCS coolant during PCS boron concentration chan~es or inadvertent dilution events. Therefore, forced circulation is requ1red except during short intervals when the requi.red loops or trains may be intentionally stopped prbvided additional constraints are followed.
The reactor cavity fi.lled to ~ 647' elevation provides backup decay heat removal capab.ility.
Decay heat is moved by natural circulation to the large mass of water:in the refueling cavity. The heat storage capacity of the filled reactor cavity provi'des a temi:>orary method of decay heat removal which provides time to restore the requireCi train of SOC.
An OPERABLE steam generator, for the purposes of this specification, must have both its primary and secondary sides intact, its tubes filled with primary coolant, and a secondary water level of at least -84% on the wide range level channels.
The specified steam generator secondary water level of
-84% ensures that at least one-third of the effective steam generator heat transfer area is cover~~
1 and is therefore sufficient to support natural circulation in the PCS *
- In addition, there must be ava1lable a method of feedwater addition and a controllable path for steam release.
A heat flow path to the lake may vary in actual component configuration, method of operation and control, but it shall always accomplish the objective of transferring decay heat from the reactor to Lake Michigan.
As a minimum, a heat flow path requires: a shutdown cooling pump, a shutdown cooling heat exchanger, a component cooling water pump, a component cooling heat exchanger; a service water pump, and appropriate piping, valves and controls for the equipment to perform its function. All of this equipment must be OPERABLE and must have adequate, but not necessarily redundant, electrical power.
3-25k Amendment No. l-,
ATIACHMENT 2 CONSUMERS POWER COMPANY PALISADES PLANT DOCKET 50-255 TECHNICAL SPECIFICATION CHANGE REQUEST SHUTDOWN COOLING (SDC)
Existing Pages Marked to Show Proposed Changes 2 Pages
'SHUTDOWN coo~ (SOC)
Specification 3.1.9.3 One SOC train shall be in operation ~roviding ~ 1000.gpm flow through the reactor core, and at least two of the means of decay heat removal listed below shall be OPERABLE:
- 1.
SOC train A consisting of an.OPERABLE SOC pump and an OPERABLE heat flow path to Lake Michigan.
- 2.
SOC train B consisting of an OPERABLE SOC pump and an OPERABLE heat flow path to Lake Michigan.
1@:::tt:::::::1:11::::::1i!i.il:i1m1i1:i::11m11:11::::::1:11,i.J1;~:11:1111rn~10:;111m:f::
Applicability Specification 3.1.9.3 applies when there is fuel in the reactor, with PCS Temperature is < 200°F and the PCS loops NOT filled.
Exceptions
- 1.
All flow through the reactor core may be intentionally stopped for up to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> provided:
- a.
- b.
- c.
No operations are permitted that would cause reduction of the PCS boron concentration or PCS inventory, and Core outlet temperature stays ~ 200°F, and Two SOC trains are OPERABLE.
- 2.
One or both SOC miiulirlU~tra ins may be intent i ona 11 y rendered i noperab 1 e for t'lfafl"ff9".... o
.. r maintenance for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> Action provided:
- a.
One SOC train is providing flow through the reactor core, and
- b.
Core outlet temperature stays ~ 200°F, and
- c.
The refueling cavity water level is ~ 647'.
- 1.
With fewer OPERABLE means of decay heat removal than required:
- a.
Immediately initiate corrective action to return a second train to OPERABLE status, and
- b.
Maintain PCS temperature as low as practical with available equipment.
- 2.
With less flow through the core than required:
- a.
Immediately suspend all operations involving a reduction in PCS boron concentration, and
- b.
Immediately initiate corrective action to return a train to operation providing flow through the core.
3-25j Amendment No. -l6-l
. 3.'i.
3.1.9 Basis
. PRIMARY COOL. SYSTEM (PCS)
SHUTDOWN COOLING The Shutdown Cooling (SOC) specifications require a minimum fiow be maintained through the reactor core and two methods of decay heat removal to be OPERABLE, in each of three situations, PCS temperature 200°F to 300°F, PCS temperature below*200°F with the loops filled, and PCS temperature below 200°F with the loops not filled.
"Loops Filled" means the PCS loops are intact, not blocked by dams, and tot a 11 y filled with cool ant.
The requirement to maintain 2810 gpm flow through the reactor core when the PCS loops are filled is based on an analysis of potential dilution events.
Maintenance of this flow assures that indication of increasing count rate will be available to warn the operator and allow compensating action.
The requirement to maintain 1000 gpm flow through the reactor core when the loops are not filled assures mixing of the PCS while allowing flow to be reduced to avoid vortexing in the SOC suction piping.
The 1000 gpm is based on operating experience, rather on analysis. With flow less tha~ 2810 gpm, Specification 3.10.1 imposes additional requirements for Shutdown Margin and limits charging pump operability. Maintaining flow through the reactor core also allows use of the SOC temperature indication to determine core outlet temperature when the core outlet thermocouples are not in service.
Natural circulation is adequate for decay heat removal, however it may not provide adequate mixing of the PCS coolant during PCS boron concentration changes or inadvertent dilution events. Therefore, forced circulation is required except during short intervals when the required loops or trains may be intentionally stopped provided additional constraints are followed.
An OPERABLE steam generator, for the purposes of this specification, must have both its primary and secondary sides intact, its tubes filled with primary coolant, and a secondary water level of at least -84% on the wide range level channels.
The specified steam generator secondary water level of
-84% ensures that at least one-third of the effective steam generator heat transfer area is coverM~ and is therefore sufficient to supfort natural circulation in the PCS'* 1*
In addition, there must be ava1 able a method of feedwater addition and a controllable path for steam release.
A heat flow path to the lake may vary in actual component configuration, method of operation and control, but it shall always accomplish the objective of transferring decay heat from the reactor to Lake Michigan.
As a minimum, a heat flow path requires: a shutdown cooling pump, a shutdown cooling heat exchanger, a component cooling water pump, a component cooling heat exchanger, a service water pump, and appropriate piping, valves and controls for the equipment to perform its function.
All of this equipment must be OPERABLE and must have adequate, but not necessarily redundant, electrical power.
3-25k Amendment No. -1&!