ML20236K646
| ML20236K646 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 08/03/1987 |
| From: | CAROLINA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20236K639 | List: |
| References | |
| 86TSB22, NUDOCS 8708070208 | |
| Download: ML20236K646 (10) | |
Text
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i OLOSURE1 TO Sc. L: NLS-87-010 PROPOSED TECHNICAL SPECIFICATION PAGES BRUNSWICK-1 CONTROL ROD BANKED POSITION WITHDRAWAL l
SEQUENCE (86TSB22) 870B070208 870003 PDR ADOCK 05000324 P
PDR 1
(5091 BAT /l ah )
SUMMARY
LIST OF REVISIONS Page No.
Description of Changes 3/41-14 Revised TS 4.1.4.l.2 to add the Banked Position Withdrawal Sequence requirement and added the word
" OPERATIONAL."
I B3/41-3 and Revised the Bases of section 3/4.1.4 to describe the l
B3/4 1-4 Control Rod Program Controls using the EPWS.
\\
(5091 BAT /leh)
(BSEP-1-97)
REACTIVITY CONTROL SYSTEMS 3/4.1.4 CONTROL ROD PROGRAM CONTROLS ROD WORTH MINIMIZER LIMITINC CONDITION FOR OPERATION 3.1.4.1 The Rod Worth Minimizer (RWM) shall be OPERABLE when THERMAL POWER is less than 20% of RATED THERMAL POWER.
APPLICABILITY: OPERATIONAL CONDITIONS 1 and 2*.
l4 ACT10N:
With the RWM inoperable, the provisions of Specification 3.0.4 are not applicable, operation may continue and control rod movement is permitted prcvided that a second licensed operator or other qualified member of the technical staff ir present at the reactor control console and verifies compliance with the prescribed control rod pattern.
SURVEILLANCE REQUIREMENTS 4.1.4.1.1 The RWM shall be demonstrated OPERABLE in OPERATIONAL CONDITION 2, l&
prior to withdrawal of control rods for the purpose of making the reactor critical and in OPERATIONAL CONDITION 1 when the RWM is initiated during l*
control rod insertion when reducing THERMAL POWER by:
A.
Verifying
>per : annunciation of the selection error of at least one out-of-se
. ce control rod, and b.
Verifyins _ae rod block function of the RWM by moving an out-of-sequence control rod.
4.1.4.1.2 The RWM shall be demonstrated OPERABLE by verifying the control rod Banked Position Withdracal Sequence input to the RWM computer is correct j
following any loading of the sequence program into the computer.
i
- Entry into OPERATIONAL CONDITION 2 and withdrawal of selected control rods is lA permitted for the purpose of determining the OPERABILITY of the RWM prior to withdrawal of control rods for the purpose of bringing the reactor to critica ity.
BRUNSWICK - UNIT 1 3/4 1-14 Amendment No.
(BSEP-1-97)
REACTIVITY CONTROL SYSTEM BASES CONTROL RODS (Continued) on a scram than has been analyzed even though control rods with inoperable accumulators may still be inserted with normal drive water pressure.
Operability of the accumulator ensures that there is a means available to insert the control rods even under the most unfavorable depressurization of the reactors.
Control rod coupling integrity is required to ensure compliance with the analysis of.the rod drop accident in the FSAR. The overtravel position feature provides the only positive means of determining that a rod is properly coupled and, therefore, this check must be performed prior to achieving criticality after reach refueling. The subsequent check is performed as a backup to the initial demonstration.
In order to ensure that the control rod patterns can be followed and, therefore, that other parameters are within their limits, the control rod position indication system must be OPERABLE.
The control rod housing support restricts the outward movement of a control rod to less than 3 inches in the event of a housing failure. The amount of rod reactivity which could be added by this small amount of rod withdrawal is less than a normal withdrawal increment and will not contribute I
to any damage to the primary coolant system. The support is not required when there is no pressure to act as a driving force to rapidly eject a drive housi,ng.
The required surveillance intervals are adequate to determine that the rods are OPERABLE and not so frequent as to cause excessive wear on the system components.
3/4.1.4 CONTROL ROD PROCRAM CONTROLS Control rod withdrawal and insertion sequences are established to assure that the maximum in sequence individual control rod or control rod segments which are withdrawn at any time during the fuel cycle could not be worth enough to result in a peak fuel enthalpy greater than 280 cal /gm in the event of a control rod drop accident. The specified sequences are characterized by homogeneous, scattered patterns of control rod withdrawal. When THERMAL POWER is greater than or equal to 20% of RATED THERMAL POWER, there is no possible rod worth which, if dropped at the design rate of the velocity limiter, could result in a peak enthalpy of 280 cal /gm. Thus, requiring the RSCS and RWM to j
be OPERABLE when THERMAL POWER is less than 20% of RATED THERMAL POWER provides adequate control.
Use of the Banked Position Withdrawal Seque'nce (BPWS) ensures that in the event of a control rod drop accident the peak fuel enthalpy will not be greater than 280 cal /gm (Reference 4).
BRUNSWICK - UNIT 1 B 3/4 1-3 Amendment No.
(BSEP-1-97)
REACTIVITY CONTROL SYSTEM BASES CONTROL ROD PROGRAM CONTROLS (Continued)
The RSCS and RWM provide automatic supervision to assure that out-of-sequence rods will not be withdrawn or inserted.
The analysis of the rod drop accident is presented in Section 15.4.6 of the Updated FSAR and the techniques of the analysis are presented in a topical l
report (Reference 1) and two supplements (References 2 and 3).
The RBM is designed to automatically prevent fuel damage in the event of erroneous rod withdrawal from locations of high power density during high power operation. Two channels are provided. Tripping one of the channels will block erroneous rod withdrawal soon enough to prevent fuel damage. This system backs up the written sequence used by the operator for withdrawal of control rods.
3/4.1.5 STANDBY LIQUID CONTROL SYSTEM The standby liquid control system provides a backup capability for maintaining the reactor suberitical in the event that insufficient rods are
' inserted in the core when a scram is called for. The volume and weight percent of poison material in solution is based on being able to bring the reactor to the subcritical condition as the plant cools to ambient condition. The temperature requirement is necessary to keep the sodium pentaborate in solution.
Checking the volume and temperature once each 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> assures that the solution is available for use.
With redundant pumps and a highly reliable control rod scram system, operation of the reactor is permitted to continue for short periods of time with the system inoperable or for longer periods of time with one of the redundant components inoperable.
Surveillance requirements are established on a frequency that assures a high reliability of the system. Once the solution-is established, boron concentration will not vary unless more boron or water is added, thus a check on the temperature and vclume once each 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> assures that the solution is available for use.
1.
C. J. Paone, R. C. Stirn, and J. A. Woodley, " Rod Drop Accident Analysis for Large BWRs, "C. E. Topical Report NEDO-10527, March 1972.
2.
C. J. Paone, R. C. Stirn, and R. M. Yound, Supplement 1 to NES0-10527, July 1972.
3.
J. A. Haum, C. J. Paone, and R. C. Stirn, addendum 2, " Exposed Cores",
supplement 2 to NEDO-10527, January 1973.
4.
NEDE-24011-P-A, " General Electric Standard Application for Reactor Fuel,"
Resision 6, Amendment 12.
F i
BRUNSWICK - UNIT 1 B 3/4 1-4 Amendment No.
m_._____
n- _. _. - _ -
ENCLOSURE 2 TO SERIAL: NLS-87-010 PROPOSED TECHNICAL SPECIFICATION PAGES BRUNSWICK-2 CONTROL ROD BANKED POSITION WITHDRAWAL SEQUENCE (86TSB22)
(5091 BAT /lah)
SUMMARY
LIST OF REVISION Page No.
Description of Changes 3/4 1-14 Revised TS 4.1.4.2 to add the Banked Position
~ Withdrawal Sequence requirement and added the word
" OPERATIONAL."
l B3/41-3 and Revised the bases of section 3/4.1.4 to describe the B3/41-4 Control Rod Program Controls using the BPWS.
l I
(5091BM/l ah )
a
(BSEP-2-98) l REACTIVITY CONTROL SYSTEMS 3/4 1.4 CONTROL ROD PROGRAM CONTROLS ROD WORTH MINIMIZER LIMITING CONDITION FOR OPERATION 3.1.4.1 The Rod Worth Minimizer (RWM) shall be OPERABLE when THERMAL POWER is less than 20% of RATED THERMAL POWER.
APPLICABILITY: OPERATIONAL CONDITIONS 1 and 2*.
l&
ACTION:
With the RWM inoperable, the provisions of Specification 3.0.4 are not applicable, operation may continue, and control rod movement is permitted provided that a second licensed operator or other qualified member of the technical staff is present at the reactor control console and verifies compliance with the prescribed control rod pattern.
SURVEILLANCE REQUIREMENTS 4.1.4.1.1 The RWM shall be demonstrated OPERABLE in OPERATIONAL CONDITION 2, lP prior to withdrawal of control rods for the purpose of making the reactor critical and in OPERATIONAL CONDITION 1 when the RWM is initiated during l4 control rod insertion when reducing THERMAL POWER by:
Verifying proper annunciation of the selection error of at least one a.
out-of-sequence control rod, and b.
Verifying the rod block function of the RWM by moving an out-of-sequence control rod.
4.1.4.1.2 The RWM shall be demonstrated OPERABLE by verifying the control rod Banked Position Withdrawal Sequence input to the RWM computer is correct l
following any loading of the sequence program into the computer.
- Entry into OPERATIONAL CONDITION 2 and withdraval of selected control rods is lk permitted for the purpose of determining the OPERABILITY of the RWM prior to withdrawal of control rods for t he purpose of bringing the reactor to criticality.
I I
i
. BRUNSWICK - UNIT 2 3/4 1-14 Amendment No.
. ( BS EP-2-98 ).
REACTIVITY CONTROL SYSTEM BASES CONTROL RODS (Continued) on a scram than has been analyzed even though. control rods with inoperable accumulators may still be. inserted with normal drive water pressure.
Operability of.the accumulator ensures that there is a means available to insert the control rods even under the most unfavorable depressurization of the reactors.
Control rod coupling integrity is required to ensure compliance with the_ analysis of the rod. drop accident'in the FSAR. The overtravel position feature.provides the only positive means.of determining that a rod is properly coupled and therefore this check must be performed prior to achieving criticality after each refueling. The subsequent check is performed as a backup to.the initial demonstration.
In' order to ensure that.the control. rod patterns can be followed and therefore that other parameters are within their limits, the control rod position indication system must be OPERABLE.
The control rod housing support restricts the outward movement'of a.
control rod to less than 3 inches in the event of a housing failure. The amount of rod reactivity which could be'added by this small amount of rod withdrawal is less than a normal withdrawal increment and will not contribute to any damage to the primary coolant system. The support is not required when there is no pressure to act as'a driving force to rapidly eject a drive housing.
The required surveillance intervals are adequate to determine that the rods are OPERABLE and not ou frequent as to cause excessive wear on the system components.
3/4.1.4 CONTROL ROD PROGRAM CONTROLS Control rod wi'thdrawal and insertion sequences are established to
' assure.that the maximum in sequence individual control rod or control rod segments which are withdrawn at any time during the fuel cycle could not be-worth enough to result'in a peak fuel enthalpy greater than 280 cal /gm in the l
event of a control rod drop accident.
The specified sequences are characterized by homogeneous, scattered patterns of control rod withdrawal.
When THERMAL POWER is greater than or equal to 20% of RATED THERMAL POWER, l
there is no possible rod worth which, if dropped at the design rate of the velocity limiter,.could result in a peak enthalpy of 280 cal /gm.
of RATED THERMAL POWER provides adequate control.
I BRUNSWICK - UNIT 2 B 3/4 1-3 Amendment No.
(BSEP-2-98) 6 REACTIVITY CONTROL SYSTEM
. BASES CONTROL' ROD PROCRAM CONTROLS (Continued)
Use of the Banked Position Withdrawal Sequence (BPWS) ensures that in the event of a control rod drop accident, the peak fuel enthalpy will not be greater than 280 cal /gm.(Reference 4).
j The.RSCS and RWM provide automatic supervision to assure that out-of-l sequence. rods will not be withdrawn or inserted.
1 The analysis of the. rod drop accident is p;esented in Section 15.4.6 of the. Updated FSAR, and the techniques of the analysis are presented in a topical. report (Reference 1) and two supplements (References 2 and 3).
The RBM is designed to automatically prevenb fuel damage in the event of erroneous rod withdrawal from locations of high power density during high power operation..Two channels are provided. Tripping one of the channels will block erroneous rod withdrawal soon enough to prevent fuel damage. This system backs up the written sequence used by the operator for withdrawal of control rods.
3/4.1.5 STANDBY LIQUID CONTROL SYSTEM The standby liquid control system provides a backup capability for maintaining the reactor suberitical in the event that insufficient rods are inserted in the core when a scram is called for. The volume and weight percent' of poison material in solution is based on being able to bring the reactor to the suberitical condition as the plant cools to ambient condition. -The' temperature r2quirement is necessary to, keep the sodium pentaborate in solution. Checking the volume and temperature once each 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> assures that the solution is available for use.
With redundant pumps and a highly reliable control rod scram system, operation of the reactor is permitted to continue for short periods of time with the system inoperable or for longer periods of time with one of the redundant components inoperable.
1.
C. J. Paone, R. C. Stirn, and J. A. Woodley, " Rod Drop Accident Analysis for Large BWRs " C. E. Topical Report NEDO-10527, March 1972.
2.
C. J. Paone, R. C. Stirn, and R. M. Yound, Supplement 1 to NED0-10527, July 1972.
3.
J.'A. Haum, C. J. Paone, and R. C. Stirn, addendum 2 " Exposed Cores" supplement 2 to NEDO-10527, January 1973.
4.
NEDE-24011-P-A, " General Electric Standard Application for Reactor Fuel,"
Revision 6, Amendment 12.
I i
BRUNSWICK - UNIT 2 B 3/4 1-4 Amendment No.