ML20087D349
| ML20087D349 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 08/04/1995 |
| From: | CAROLINA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20087D323 | List: |
| References | |
| NUDOCS 9508100290 | |
| Download: ML20087D349 (7) | |
Text
BC REACTIVITY CONTROL SYSTEMS'
- LIMITING CONDITION'FOR OPERATION (Continued)_
ACTION:
(Continued) 2 '.
If the inoperable control rod (s) is inserted:
a)
Within one hour disarm the associated directional control valves either:
1)
Electrically. or Hydraulically by.'closin 2) water isolation valves.g the drive water and exhaust b)
Otherwise,beinadleastHOTSHUTDOWNwithinthenext12 hours.
~
3.
The provisions of Specification 3.0.4 are not applicable.
I c.
With more than 8 control rods inoperable, be in at least HOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
SURVEILLANCE REQUIREMENTS l
1 II I IIII 4.1.3.1.1 The scram discharge volume drain and vent valves shall be demonstrated OPERABLE at least once per 31 days by:*
a.
Verifying each valve to be open.
~
b.
Cycling each valve at least one complete cycle of full travel.
4.1.3.1.2 All withdrawn control rods not required to have their directional:
control' valves disarmed electrically or hydraulically shall be demonstrated OPERABLE by moving each control rod at least one notch:
a.
At least once per 7 days when above the preset power level of the RWM and b.
At least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />'when above the preset power-level of the RWM and any control rod is imovable as a result of excessive friction or mechanical interference.
4.1.3.1.3 All withdrawn control rods shall be determined OPERABLE by demonstrating the scram discharge volume drain and vent valves OPERABLE. when the reactor protection system logic is tested per Specification 4.3.1.2. by verifying that the drain and vent valves:
a.
Close within 30 seconds after receipt of a signal for control rods to scram. and o.
Open when the scram signal is reset or the scram discharge volume trip is bypassed.
These valves may be closed intermittently for testing under administrative control, PR DC O O O 24 P
PDR BRUNSWICK -' UNIT 1 3/4 1-4 Amendment No.
i'
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-T REACTfVITY CONTROL SYSTEMS BASES I
CONTROL RODS (Continued) potential effects of the rod ejection accident are limited.
The ACTION statements permit variations from the basic requirements but at the same time
-impose more restrictive criteria for continued operation. A limitation on inoperable rods is set such that the resultant effect on total rod worth and
. scram shape will be kept to a minimum. The requirements for the various scram time measurements ensure that any indication of systematic problems with rod drives will be investigated on a timely' basis.
Damage within the control rodfdrive mechanism could be a generic problem: therefore, with a control rod imovable because of excessive friction i
or mechanical interference. operation of the reactor is limited to a time period which is reasonable to determine the cause of the inoperability and at the same time prevent operation with a large number of inoperable control rods.
)
Control rods that are ino3erable for other reasons are permitted to be taken out of service 3rovided tlat those in the non-fully-inserted position are consistent with tie SHUTDOWN MARGIN requirements.
With one or more withdrawn control rods inoperable for reasons other than being stuck, operation may continue provided within one hour, either a) the inoperable withdrawn control rod (s) are fully inserted and disarmed 1
l (electrically or hydraulically), or b) the inoperable control rod (s) are separated from other inoperable control rods by at least two control cells in all directions, and the insertion capability of each inoperable control rod is demonstrated by inserting the control rod at least one notch by drive water pressure within the normal operating range.
Inserting a control rod ensures the shutdown and scram capabilities are not adversely affected. Adequate separation of inoperable withdrawn control rods (inoperable for reasons other than being immoveable or untrippable) is required to ensure consistency with l
t.he scram reactivity function assumed in the reload licensing analysis.
i Inserted inoperable control rods are disarmed to prevent inadvertent withdrawal during subsequent operations. The control rods can be hydraulically disarmed by closing the drive and exhaust water isolation valves, or electrically disarmed by disconnecting power from all four directional control valve solenoids.
Technical Specification 3.1.3.1. ACTION b is generic to the other control rod Technical Specifications 3.1.3.2. 3.1.3.4. 3.1.3.5. 3.1.3.6. and 3.1.3.7. which identify individual types of control rod inoperability.
Each of the individual control rod Technical Specifications identifies that the provisions of Technical Specification 3.0.4 are not applicable provided the specification ACTIONS are satisfied, the affected control rod is declared inoperable, and the requirements of Technical Specification 3.1.3.1 are satisfied.
Inclusion of an exemption from the requirements of Technical Specification 3.0.4 in Specification 3.1.3.1. ACTION b allows changing from OPERATIONAL CONDITION 2 to OPERATIONAL CONDITION 1 with inoperable control rods and is consistent with the individual control rod operability specifications listed above (Reference 8).
a l
BRUNSWICK - UNIT 1 B 3/4 1-2 Amendment No.
l
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l REACTIVITY CONTROL SYSTEMS q
BASES CONTROL ROOS (Continued)
The number of control rods permitted to be inoperable could be more than the eight allowed by the specification, but the occurrence of eight ino)erable rods could be indicative of a generic problem and the reactor must be slut down for investigation and resolution of the problem.
The control rod system is analyzed'to bring the reactor subcritical at a rate fast enough to prevent the MPCR from becoming less than the Safety Limit MCPR of Specification 2.1.2 during the limiting power transient analyzed in Section 14.3 of the FSAR. This analysis shows t1at the negative reactivity rates resulting from the scram with the average response of all the drives as given in the s)ecifications, provide the required protection and MCPR remains greater than t1e Safety Limit MCPR of Specification 2.1.2 The occurrence of scram times longer than those specified should be viewed as an indication of a systemic problem with the rod drives and, therefore, the surveillance interval is reduced in order to prevent operation of the reactor for long periods of time with a potentially serious problem.
Control rods with inoperable accumulators are declared inoperable and Specification 3.1.3.1 then applies.
This prevents a pattern of inoperable accumulators that would result in less reactivity insertion l
l i
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l
]
BRUNSWICK - UNIT 1 8 3/4 1-2a Amendment No.
1
p
-1 L
s ENCLOSURE 2 -
BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 NRC DOCKET NOS. 50-325 AND 50-324 OPERATING LICENSE NOS. DPR-71 AND DPR-62 REQUEST FOR LICENSE AMENDMENTS CONTROL ROD DRIVE ACCUMULATOR OPERABILITY TYPED TECHNICAL SPECIFICATION PAGES - UNIT 2 0
g' l}
/.g a
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%,,/- }{
t REACTIVITY CONTROL SYSTEMS-eLIMITING CONDITION'FOR OPERATION ~(Continued)'
(
' ACTION:
(Continued) 2.
If the inoperable control rod (s) is inserted:
a)-
Within one hour: disarm the associated directional control valves-either:
1)
Electrically, or 2)
Hydraulically by closing the drive water and exhaust water isolation valves.
b)
Otherwise.bein5tleastHOTSHUTDOWNwithinthenext12 4
hours.
3.
The provisions of Specification 3.0.4 are not applicable.
^
I c.
With more than 8 control rods inoperable, be in at least HOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
SURVEILLANCE REQUIREMENTS 4.1.3.1.1 The scram discharge volume drain and vent valves 'shall be demonstrated OPERABLE at least once per 31 days by:*
p a.
Verifying each valve to be open.
b.
Cycling each valve at least one complete cycle of_ full travel.
4.1.3.1.2 -All withdrawn control rods not required to have their directional control valves disarmed electrically or hydraulically shall be demonstrated OPERABLE by moving each control rod at least one notch:
a.
At least once per 7 days when above the preset power level of the RWM and b.
At least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when above the preset power level of the RWM and any control rod is immovable as a result of excessive friction or mechanical interference.
4.1.3.1.3 All withdrawn control rods shall be determined OPERABLE by demonstrating the scram discharge volume drain and vent valves OPERABLE, when the reactor protection system logic is tested per Specification 4.3.1.2, by verifying that the drain and vent valves:
a.
Close within 30 seconds after receipt of a signal for control rods to scram, and b.
Open when the scram signal is reset or the scram discharge volume trip is bypassed.
These valves may be closed intermittently for testing under administrative control.
E
-BRUNSWICK - UNIT 2 3/4-1-4 Amendment No.
- l
y u
~
REACTfVITY CONTROL SYSTEMS BASES q
CONTROL R005 (Continued)
. potential effects of the rod ejection accident are limited.
The ACTION statements permit variations from the basic requirements but at the same time impose more restrictive criteria for continued operation.
A limitation on inoperable rods is set such-that the resultant effect on total rod worth and scram shape will be kept to a minimum.
The requirements for the various scram l
time measurements ensure that any indication of systematic problems with rod drives will be investigated on a timely basis.
Damagewithinthecontrolroditrivemechanismcouldbeageneric-problem: therefore, with a control rod immovable because of excessive friction or mechanical interference, operation of the reactor is limited to a time period which is reasonable to determine-the cause of the inoperability and at the same time _ prevent operation with a large number of inoperable control rods.
Control rods that are ino)erable for other reasons are permitted to be.
taken out of service. ]rovided tlat those in the non-fully-inserted position are consistent with t1e SHUTDOWN MARGIN requirements.
With one or more withdrawn control rods inoperable for reasons other than being stuck, operation may continue provided within one hour, either'-
a) the inoperable withdrawn control rod (s) are fully inserted and disarmed (electrically or hydraulically), or b) the inoperable control rod (s) are separated from other inoperable control rods by at least two control cells in all directions, and the insertion capability of each inoperable control rod is demonstrated by inserting the control rod at least one notch by drive water pressure within the normal operating range.
Inserting a control rod ensures the shutdown and scram capabilities are not adversely affected. Adequate separation of inoperable withdrawn control rods (inoperable for reasons other than being immoveable or Lntrippable) is required to ensure consistency with the scram reactivity function assumed in the reload licensing analysis.
Inserted inoperable control rods are disarmed to prevent inadvertent withdrawal during subsequent operations. The control rods can be-hydraulically disarmed by closing the drive and exhaust water isolation valves, or electrically disarmed by disconnecting power from all four directional control valve solenoids.
Technical Specification 3.1.3.1. ACTION b is generic to the other control rod Technical Specifications 3.1.3.2. 3.1.3.4. 3.1.3.5. 3.1.3.6.-and 3.1.3.7. which identify individual types of control rod inoperability.
Each of the individual control rod Technical Specifications identifies that the provisions of Technical Specification 3.0.4 are not applicable provided the specification ACTIONS are satisfied, the affected control rod is declared inoperable, and the requirements of Technical Specification 3.1.3.1 are satisfied.
Inclusion of an exemption from the requirements of Technical Saecification 3.0.4 in Specification 3.1.3.1. ACTION b allows changing from i
03ERATIONAL CONDITION 2 to OPERATIONAL CONDITION 1 with inoperable control rods and is consistent with the individual control rod operability specifications listed above (Reference 8).
BRUNSWICK - UNIT 2
.B 3/4 1-2 Amendment No.
l
~
REACTIVITY C0ffTROL SYSTEMS BASES CbHTROLRODS(Continued)
The number of control rods permitted to be inoperable could be more than the eight allowed by the specification. but the occurrence of eight inoperable rods could be indicative of a generic problem and the reactor must be slut down for investigation and resolution of the problem.
The control rod system is analyzed to bring the reactor subcritical at a rate fast enough to prevent the MPCR from becoming less than the Safety Limit MCPR of Specification 2.1.2 during the limiting aower transient analyzed in Section 14.3 of the FSAR. Thisanaljsisshowstlatthenegativereactivity rates resulting from the scram with the average response of all the drives as given in the specifications, provide the required protection and MCPR remains greater than the Safety Limit MCPR of Specification 2.1.2 The occurrence of scram times longer than those specified should be viewed as an indication of a systemic problem with the rod drives and. therefore the surveillance interval is reduced in order to prevent operation of the reactor for long periods of time with a potentially serious problem.
Control rods with inoperable accumulators are declared inoperable and Specification 3.1.3.1 then applies. This prevents a pattern of inoperable accumulators that would result in less reactivity insertion BRUNSWICK - UNIT 2 B 3/4 1-2a Amendment No. I i