ML20095A173

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Proposed Tech Specs,Changing Minimum Allowable Control Rod Scram Accumulator Pressure & Charging Water Header Pressure from Value of 955 Psig to Value of 940 Psig
ML20095A173
Person / Time
Site: Peach Bottom  Constellation icon.png
Issue date: 11/30/1995
From:
PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
Shared Package
ML20095A165 List:
References
NUDOCS 9512070013
Download: ML20095A173 (20)
v • d • e


Text

l 3,.

. Control R:d Scraa Accumulators

  • 3.1.5 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Two or more control B.1 Restore charging 20 minutes from rod scram accumulators water header pressure discovery of 1 inoperable with to k %5 psig. Condition B reactor steam dome 940 concurrent with pressure m 900 psig. charging water header pressure

< % E psig 94o AtiQ B.2.1 --------NOTE---------

Only applicable if the associated control rod scram time was within the limits of Table 3.1.4-1 during ,

the last scram time l Surveillance.

Declare the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> associated control rod scram time

" slow."

08 B.2.2 Declare the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> associated control rod inoperable.

(continued)

PBAPS UNIT 2 3.1-16 Amendment No. 210 9512070013 951130 PDR ADOCK 0500o277 P. . _ _ ._ PDR_ __,

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,j

.' 3.1.5 ,

i 1 ACTIONS (continued) )

' CONDITION REQUIRED ACTION COMPLETION TIME )i i

1 d

C. One or more control C.1 Verify all control Immediately upon j rod scram accumulators rods associated with discovery of inoperable with inoperable charging water ,

reactor steam dome accumulators are header pressure >

j pressure < 900 psig, fully inserted. < JS5 psig I Ho

! m

)

i C.2 Declare the I hour i i associated control l i rod inoperable. l 1 ,

l 2

i D. Required Action B.1 or D.1 --------NOTE---------

C.) and associated Not applicable if all i Completion Time not inoperable control

! met. rod scram

! accumulators are

associated with fully 1

inserted control rods.

Place the reactor Immediately mode switch in the shutdown position.

I

-4 SURVEILLANCE REQUIREMENTS j 1

SURVEILLANCE FREQUENCY

! SR 3.1.5.1 Verify each control rod scram accumulator 7 days pressure is a:DB5 psig.

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PBAPS UNIT 2 3.1-17 Amendment No. 210 e

f

S. i Control Rod OPERABILITY--Refueling  !

3.9.5 3.9 REFUELING OPERATIONS i 3.9.5 Control Rod OPERABILITY--Refueling LCO 3.9.5 Each withdrawn control rod shall be OPERABLE.

l APPLICABILITY: MODE 5.

~

i ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME  :

i A. One or more withdrawn A.1 Initiate action to Immediately control rods fully insert i inoperable. inoperable withdrawn control rods.  ;

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.9.5.1 -------------------NOTE--------------------

Not required to be performed until 7 days after the control rod is withdrawn.

Insert each withdrawn control rod at least 7 days one notch.

SR 3.9.5.2 Verify each withdrawn control rod scram 7 days accumulator pressure is a:)65 psig.

940 i

PBAPS UNIT 2 3.9-8 Amendment No. 210

SDM Test--Refueling  :

-. 3.10.8 ,.

SURVEILLANCE REQUIRENENTS (continued)

SURVEILLANCE FREQUENCY SR .3.10.8.5 Verify each withdrawn control rod does not Each time the j go to the withdrawn overtravel position. control rod is .

withdrawn to

" full out" position -

8!E Prior to satisfying r LC0 3.10.8.c requirement after work on ,

control rod or CRD System that could affect coupling  ;

SR 3.10.8.6 Virify CRD charging water header pressure 7 days a: DSS psig.

94o l

1 l

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PBAPS UNIT 2 3.10-23 Amendment No. 210 1

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BASES ACTIONS A.1 and A.2 (continued) control rod is declared inoperable (Required Action A.2) and LCO 3.1.3 is entered. This would result in requiring the affected control rod to be fully inserted and disarmed, thereby satisfying its intended function, in accordance with ACTIONS of LC0 3.1.3.

The allowed Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is reasonable, based on the large number of control rods available to provide the scram function and the ability of the affected control rod to scram only with reactor pressure at high reactor pressures.

. B.1. B.2.1. and B.2.2 With two or more control rod scram accumulators inoperable and reactor steam dome pressure 2: 900 psig, adequate pressure must be supplied to the charging water header.

With inadequate charging water pressure, all of the accumulators could become inoperable, resulting in a potentially severe degradation of the scram performance.

Therefore, within 20 minutes from discovery of charging N" water header pressure <.ir55 psig concurrent with condition B, adequate charging water header pressure must be restored. The allowed Completion Time of 20 minutes is reasonable, to place a CRD pump into service to restore the j charging water header pressure, if required. This Completion Time is based on the ability of the reactor ,

pressure alone to fully insert all control rods.

The control rod may be declared " slow," since the control I rod will still scram using only reactor pressure, but may  !

not satisfy the times in Table 3.1.4-1. Required Action B.2.1 is modified by a Note indicating that declaring the control rod " slow" only applies if the associated

, control scram time is within the limits of Table 3.1.4-1 during the last scram time test. Otherwise, the control rod would already be considered " slow" and the further degradation of scram performance with an inoperable accumulator could result in excessive scram times. In this event, the associated control rod is declared inoperable (Required Action B.2.2) and LCO 3.1.3 entered. This would (continued)

PBAPS tlNIT 2 B 3.1-31 Revision No. 0

J e, l

- Control Rod Scram Accumulators B 3.1.5 BASES ACTIONS B.1. B.2.1. and B.2.2 (continued) result in requiring the affected control rod to be fully inserted and disarmed, thereby satisfying its intended function in accordance with ACTIONS of LC0 3.1.5.

The allowed Completion Time of I hour is reasonable, based on the ability of only the reactor pressure to scram the control rods and the low probability of a DBA or transient occurring while the affected accumulators are inoperable.

1 C.1 and C.2 With one or more control rod scram accumulators inoperable and the reactor steam dome pressure < 900 psig, the pressure supplied to the charging water header must be adequate to ensure that accumulators remain charged. With the reactor steam dome pressure < 900 psig, the function of the accumulators in providing the scram force becomes much more  ;

important since the scram function could become severely degraded during a depressurization event or at low reactor pressures. Therefore, immediately upon discovery of 94C) - charging water header pressure <;955 psig, concurrent with 1 Condition C, all control rods associated with inoperable I accumulators must be verified to be fully inserted. l Withdrawn control rods with inoperable accumulators may fail to scram under these low pressure conditions. The  !

associated control rods must also be declared inoperable within I hour. The allowed Completion Time of I hour is reasonable for Required Action C.2, considering the low  !

probability of a DBA or transient occurring during the time l that the accumulator is inoperable.  ;

D.d i

The reactor mode switch must be immediately placed in the i shutdown position if either Required Action and associated l Completion Time associated with the loss of the CRD charging pump (Required Actions B.1 and C.1) cannot be met. This 1 ensures that all insertable control rods are inserted and I that the reactor is in a condition that does not require the (continued) 1 PBAPS UNIT 2 B 3.1-32 Revision No. O

l e.'

+ Control Rod Scram Accumulators

  • B 3.1.5 BASES ACTIONS Q 1 (continued)

I active function (i.e., scram) of the control rods. This Required Action is modified by a Note stating that the l action is not applicable if all cont'o1 rods associated with  ;

the inoperable scram accumulators are fully inserted, since i the function of the control rods has been performed.

SURVEILLANCE SR 3.1.5.1 .

REQUIREMENTS SR 3.1.5.1 requires that the accumulator pressure be checked  :

every 7 days to (nsure adequate accumulat~or pressure exists to provide sufficient scram force. The primary indicator of j accumulator OPERABILITY is the accumulator pressure. A  ;

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minimum accumulator pressure is specified, below which the capability of the accumulator to perform its intended function becomes degraded and the accumulator is considered cf 40 '- inoperable. The minimum accumulator pressure oflB&E psig is  ;

well below the expected pressure of approximately 1450 psig i (Ref.1). Declaring the accumulator inoperable when the minimum pressure is not maintained ensures that significant degradation in scram times does not occur. The 7 day Frequency has been shown to be acceptable through operating experience and takes into account indications available in 1 the control room.

REFERENCES 1. UFSAR, Section 3.4.5.3 and Figure 3.4.10.

2. UFSAR, Appendix K,Section VI.
3. UFSAR, Chapter 14.

PBAPS UNIT 2 B 3.1-33 Revision No. 0

Control Rod OPERABILITY-Refueling

- B 3.9.5 B 3.9 REFUELING OPERATIONS B 3.9.5 Control Rod OPERABILITY-Refueling BASES BACKGROUND Contral rods are components of the Control Rod Drive-(CRD)-

System, the primary reactivity control system for the

~

reactor. In conjunction with the Reactor Protection System, the CRD System provides the means for the reliable control of reactivity changes during refueling operation. In addition, the control rods provide the capability to maintain the reactor subcritical under all conditions and to limit the potential amount and rate of reactivity increase caused by a malfunction in the CRD System.

UFSAR design criteria require that one of the two required independent reactivity control systems be capable of holding the reactor core subcritical under cold conditions (Ref.1).

The CRD System is the system capable of maintaining the reactor suberitical in cold conditions.

APPLICABLE Prevention and mitigation of prompt reactivity excursions SAFETY ANALYSES during refueling are provided by refueling interlocks (LCO 3.9.1 and LCO 3.9.2), the SDM (LCO 3.1.1), the intermediate range monitor neutron flux scram (LCO 3.3.1.1),

and the control rod block instrumentation (LCO 3.3.2.1).

The safety analyses for the control rod withdrawal error during refueling (Ref. 2) and the fuel assembly insertion error (Ref. 3) evaluate the consequences of control rod withdrawal during refueling and also fuel assembly insertion with a control rod withdrawn. A prompt reactivity excursion during refueling could potentially result in fuel failure with subsequent release of radioactive material to the environment. Control red scram provides protection should a prompt reactivity excursion occur.

Control rod OPERABILITY during refueling satisfies Criterion 3 of the NRC Policy Statement.

LCO Each withdrawn control rod must be OPERABLE. The withdrawn control rod is considered OPERABLE if the scram accumulator pressure is a:186 psig and the control rod is capable of 940 (continued)

PBAPS UNIT'2 B 3.9-14 Revision No. O

l Control Rod OPERABILITY-Refueling

- B 3.9.5 BASES 1

LC0 being automatically inserted upon receipt of a scram signal.  ;

(continued) Inserted control rods have already completed their reactivity control function, and therefore, are not required to be OPERABLE.

APPLICABILITY During MODE 5, withdrawn control rods must be OPERABLE to

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ensure that in a scram the control rods will insert and provide the required negative reactivity to maintain the reactor subcritical.

For MODES I and 2, control rod requirements are found in  !

LCO 3.1.2, " Reactivity Anomalies," LCO 3.1.3, " Control Rod  :

OPERABILITY," LCO 3.1.4, " Control Rod Scram Times," and ,

LCO 3.1.5, " Control Rod Scram Accumulators." During MODES 3  ;

and 4, control rods are not able to be withdrawn since the reactor mode switch is in shutdown and a control rod block -

is applied. This provides adequate requirements for control rod OPERABILITY during these conditions.

ACTIONS Ad With one or more withdrawn control rods inoperable, action must be immediately initiated to fully insert the inoperable i control rod (s). Inserting the control rod (s) ensures the shutdown and' scram capabilities are not adversely affected. ,

Actions must continue until the inoperable control rod (s) is  ;

! fully inserted. j i l

, SURVEILLANCE SR 3.9.5.1 and SR 3.9.5.2 5 '

REQUIREMENTS During MODE 5, the OPERABILITY of control rods is primarily  :

required to ensure a withdrawn control rod will

automatically insert if a signal requiring a reactor

, shutdown occurs. Because no explicit analysis exists for l automatic shutdown during refueling, the shutdown function

is' satisfied if the withdrawn control rod is capable of '
automatic insertion and the associated CRD scram accumulator j pressure is a
psig.

l

! The 7 day Frequency takes into consideration equipment '

reliability, procedural controls over the scram

, accumulators, and control room alarms and indicating lights

that indicate low accumulator charge pressures.

(continued)

. i i

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PBAPS UNIT 2 B 3.9-15 Revision No. O  !

b

____.__.-_m - _. . . ~ , _ _ m _._. _ __, _

SDM Test--Refueling B 3.10.8 BASES SURVEILLANCE SR 3.10.8.6 I

REQUIREMENTS (continued) CRD charging water header pressure verification is performed to ensure the motive force is available to scram the control rods in the event of a scram signal. Since the reactor is depressurized in MODE 5, there is insufficient reactor pressure to scram the control rods. Verification of

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charging water header pressure ensures that if a scram were required, capability for rapid control rod insertion would D exist. The minimum pressure of $5E psig is well below the expected pressure of approximately 1450 psig while still ensuring sufficient pressure for rapid control rod insertion. The 7 day Frequency has been shown to be acceptable through operating experience and takes into account indications available in the control room.

REFERENCES 1. NEDE-24011-P-A-US, General Electric Standard Application for Reactor Fuel, Supplement for United States, February 1991.

2. Letter from T. Pickens (BWROG) to G.C. Lainas, NRC,

" Amendment 17 to General Electric Licensing Topical Report NEDE-24011-P-A," August 15, 1986.

1 PBAPS UNIT 2 B 3.10-36 Revision No. 0

s. Control Rod Scram Accumulators 1

. 3.1.5

)

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME l

B. Two or more control B.1 Restore charging 20 minutes from  !

rod scram accumulators water header pressure discovery of inoperable with to a: 955 psig. Condition B reactor steam done 94o concurrent with pressure 2: 900 psig. charging water header pressure

< 155 psig 940 AND B.2.1 --------NOTE---------

Only applicable if the associated control rod scram time was within the limits of  ;

Table 3.1.4-1 during the last scram time Surveillance.

Declare the I hour  !

associated control rod scram time

" slow."

QB B.2.2 Declare the I hour associated control rod inoperable.

I (continued) '

l l

PBAPS UNIT 3 3.1-16 Amendment No. 214

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j

I

, - Control Rod Scram Accumulators .

s. 3.1.5 '

ACTIONS (continued) l.

l CONDITION REQUIRED ACTION COMPLETION TIME 4

C. One or more control C.1 Verify all control Immediately upon rod' scram accumulators rods associated.with discovery of inoperable with inoperable charging water i reactor steam dome accumulators are header pressure i

j. pressure < 900 psig, fully inserted. < SS1f psig j

940  !

l AND t i

C.2 Declare the I hour associated control  :

rod inoperable.

l 1

l D. Required Action B.1 or D.1 --------NOTE---------  !

C.1 and associated Not applicable if all
Completion Time not inoperable control

. met. rod scram

accumulators are i associated with fully inserted control i

rods.

Place the reactor Immediately i mode switch in the j shutdown position.

t a

i i SURVEILLANCE REQUIREMENTS 4 SURVEILLANCE FREQUENCY i

i

. SR 3.1.5.1 Verify each contrpl rod scram accumul'ator 7 days i

! pressure is a: 955 psig.

2 940 i

i

j. PBAPS UNIT 3 3.1-17 Amendment No. 214 f

l

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Control Rod OPERABILITY--Refueling

.' 3.9.5 3.9 REFUELING OPERATIONS 3.9.5 Control Rod OPERABILITY--Refueling I LC0 3.9.5 Each withdrawn control rod shall be OPERABLE.

l APPLICABILITY: MODE 5.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or more withdrawn A.1 Initiate action to Immediately control- rods fully insert inoperable. inoperable withdrawn control rods. ,

i SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.9.5.1 -------------------NOTE--------------------

Not required to be performed until 7 days after the control rod is withdrawn.

Insert each withdrawn control rod at least 7 days one notch.

SR 3.9.5.2 Verify each withdrawn control rod scram 7 days accumulator pressure is at )65 psig.

940 a

i

, PBAPS UNIT 3 3.9-8 Amendment No. 214 1

') l l

SDM Test--Refueling j 3.10.8 !

)

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY l 1

SR 3.10.8.5 Verify each withdrawn control rod does not Each time the go to the withdrawn overtravel position. control rod is withdrawn to

" full out"  :

position  !

A!iD Prior to satisfying LC0 3.10.8.c requirement after work on control rod or CRD System that could affect coupling SR 3.10.8.6 Verify CRD charging water header pressure 7 days a: 965 psig.

94o )

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i I

l l

. i l

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j PBAPS UNIT 3 3.10-23 Amendment No. 214 l l

l

i . Control Rod Scram Accumulators B 3.1.5 BASES i

4 ACTIONS A.1 and A.2 (continued) 4 i_ control rod is declared inoperable (Required Action A.2) and LCO 3.1.3 is entered. This would result in requiring the ,

4 affected control rod to be fully inserted and disarmed, l thereby satisfying its intended function, in accordance with

, ACTIONS of LCO 3.1.3.

I I L The allowed Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is reasonable, based

! on the large number of control rods available to provide the scram function and the ability of the affected control rod

to scram only with reactor pressure at high reactor _
pressures.

i

! B.l. B.2.1. and B.2.2 i

With two or more control rod scram accumulators inoperable i and reactor steam done pressure a: 900 psig, adequate e pressure must be supplied to the charging water header.

With inadequate charging water pressure, all of the i accumulators could become inoperable, resulting in a

! potentially severe degradation of the scram performance.

?

Therefore. within 20 minutes from discovery of charging H water header pressure <.PS1fpsig concurrent with

Condition B, adequate charging water header pressure must be

! restored. The allowed Completion Time of 20 minutes is .

l reasonable, to place a CRD pump into service to restore the '

i charging water header pressure, if required. This i

Completion Time is based on the ability of the reactor pressure alone to fully insert all control rods.

4 The control rod may be declared " slow," since the control l rod will still scram using only reactor pressure, but may

not satisfy the times in Table 3.1.4-1. Required
Action B.2.1 is modified by a Note indicating that declaring the control rod " slow" only applies if the associated
control scram time is within the limits of Table 3.1.4-1 i during the last scram time test. Otherwise, the control rod would already be considered " slow" and the further degradation of scram performance with an inoperable accumulator could result in excessive scram times. In this event, the associated control rod is declared inoperable
(Required Action B.2.2) and LCO 3.1.3 entered. This would (continued)

! PBAPS UNIT 3 B 3.1-31 Revision No. O

_. _ . . _ _ ~ _ _ _ ._. _. _ _ . _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ . .

BASES ACTIONS B.I. B.2.1. and B.2.2 (continued) result in requiring the affected control rod to be fully inserted and disarmed, thereby satisfying its intended  ;

function in accordance with ACTIONS of LCO 3.1.3.

5 The allowed Completion Time of I hour is reasonable, based

' on the ability of only the reactor pressure to scram the control rods and the low probability of a DBA or transient ,

occurring while the affected accumulators are inoperable.

1 1

1 C.1 and C.2  ;

! With one or more control rod scram accumulators inoperable and the reactor steam dome pressure < 900 psig, the pressure >

supplied to the charging water header must be adequate to

, ensure that accumulators remain charged. With the reactor steam dome pressure < 900 psig, the function of the i accumulators in providing the scram force becomes 'much more important since the scram function could become severely l degraded during a depressurization event or at low reactor pressures. Therefore.-immediately upon discovery of j

HO cnarging water header pressure < ,951Fpsig, concurrent with i

Condition C, all control rods associated with inoperable accumulators must be verified to be fully inserted.

Withdrawn control rods with inoperable accumulators may fail to scram under these low pressure conditions. The associated control rods must also be declared inoperable within I hour. The allowed Completion Time of I hour is reasonable for Required Action C.2, considering the low

< probability of a DBA or transient occurring during the time l

that the accumulator is inoperable.

M i

The reactor mode switch must be immediately placed in the

shutdown position if either Required Action and associated
completion Time associated with the loss of the CRD charging pump (Required Actions B.1 and C.1) cannot be met. This

! ensures that all insertable control rods are inserted and that the reactor is in a condition that does not require the (continued) f r

PBAPS UNIT 3 B 3.1-32 Revision No. 0 1

. Centrol Rcd Scram Accumulators l B 3.1.5 i

BASES l

l j . ACTIONS E l .(continued) l I

active function (i.e., scram) of the control rods. This 4 Required Action is modified by a Note stating that the  !

action is not applicable if all control rods associated with the inoperable scram accumulators are fully inserted, since .

the function of the control rods has been performed.

} SURVEILLANCE SR 3.1.5.1

REQUIREMENTS
SR 3.1.5.1 requires that the accumulator pressure be checked
every 7 days to ensure adequate accumulator pressure exists

! to provide sufficient scram force. The primary indicator of j accumulator OPERABILITY is the accumulator pressure. A i minimum accumulator pressure is specified, below which the i capability of the accumulator to perform its intended

! function becomes dearaded and the accumulator is considered l l

HO inoperable. The minimum accumulator pressure of.955 psig is ,

! well below the expected pressure of approximately 1450 psig l (Ref. 1). Declaring the accumulator inoperable when the 1 minimum pressure is not maintained ensures that significant

degradation in scram times does not occur. The 7 day l Frequency has been shown to be acceptable through operating i

experience and takes into account indications available in the control room.

! REFERENCES 1. UFSAR, Section 3.4.5.3 and Figure 3.4.10.

! 2. UFSAR, Appendix K,Section VI.

3. UFSAR, Chapter 14.

i

)

i I

PBAPS UNIT 3 8 3.1-33 Revision No. 0

~

System, the primary reactivity control system for the reactor. In conjunction with the Reactor Protection System, the CRD System provides the means for the reliable control of reactivity changes during refueling operation. In addition, the control rods provide the capability to maintain the reactor subcritical under all conditions and to limit the potential amount and rate of reactivity increase caused by a malfunction in the CRD System.

UFSAR design criteria require that one of the two required independent reactivity control systems be capable of holding the reactor core subcritical under cold conditions (Ref.1).

The CRD System is the system capable of maintaining the reactor subcritical in cold conditions.

APPLICABLE Prevention and mitigation of prompt reactivity excursions SAFETY ANALYSES during refueling are provided by refueling interlocks (LC0 3.9.1 and LC0 3.9.2), the SDM (LC0 3.1.1), the j intermediate range monitor neutron flux scram (LC0 3.3.1.1),  ;

and the control rod block instrumentation (LC0 3.3.2.1). l l

The safety analyses for the control rod withdrawal error 1 during refueling (Ref. 2) and the fuel assembly insertion error (Ref. 3) evaluate the consequences of control rod withdrawal during refueling and also fuel assembly insertion with a control rod withdrawn. A prompt reactivity excursion during refueling could potentially result in fuel failure with subsequent release of radioactive material to the environment. Control rod scram provides protection should a prompt reactivity excursion occur.

Control rod OPERABILITY during refueling satisfies Criterion 3 of the NRC Policy Statement.

I LC0 Each withdrawn control rod must be OPERABLE. The withdrawn i control rod is considered OPERABLE if the scram accumulator '

pressure is 2:y&S psig and the control rod is capable of 940 (continued)

PBAPS UNIT 3 B 3.9-14 Revision No. O I

. ...e

' B 3.9.5

, BASES LC0 being automatically inserted upon receipt of a scram signal. ,

(continued) Inserted control rods have already completed their reactivity control function, and therefore, are not required to be OPERABLE.

APPLICABILITY During MODE 5, withdrawn control rods must be OPERABLE to  !

- ensure that in a scram the contro' rods will insert and provide the required negative reactivity to maintain the reactor subcritical.

For MODES 1 and 2, control rod requirements are found in LC0 3.1.2, " Reactivity Anomalies," LC0 3.1.3, " Control Rod OPERABILITY," LC0 3.1.4, " Control Rod Scram Times," and LC0 3.1.5, " Control Rod Scram Accumulators." During MODES 3 and 4, control rods are not able to be withdrawn since the <

reactor mode switch is in shutdown and a control rod block is applied. This provides adequate requirements for control  :

rod OPERABILITY during these conditions.  !

l ACTIONS A.1 l i

With one or more withdrawn control rods inoperable, action must be immediately initiated to fully insert the inoperable control rod (s). Inserting the control rod (s) ensures the shutdown and scram capabilities are not adversely affected.

Actions must continue until the inoperable control rod (s) is fully inserted.

- SURVEILLANCE SR 3.9.5.1 and SR 3.9.5.2 REQUIREMENTS During MODE 5, the OPERABILITY of control rods is primarily required to ensure a withdrawn control rod will automatically insert if a signal requiring a reactor shutdown occurs. Because no explicit analysis exists for automatic shutdown during refueling, the shutdown function is satisfied if the withdrawn control rod is capable of automatic insertion and the associated CRD scram accumulator pressure is 2: 9 % psig.

94o The 7 day Frequency takes into consideration equipment reliability, procedural controls over the scram accumulators, and control room alarms and indicating lights that indicate low accumulator charge pressures.

(continued)

PBAPS UNIT 3 B 3.9-15 Revision No. O  !

l

  • *- SDM Test-Refueling

,. B 3.10.8 BASES' SURVEILLANCE SR 3.10.8.6 REQUIREMENTS (continued) CRD charging water header pressure verification is performed to ensure the motive force is available to scram the control rods in the event of a scram signal. Since the reactor is depressurized in MODE 5, there is insufficient reactor pressure to scram the control rods. Verification of

- charging water header pressure ensures that if a scram were required, capability for rapid control rod insertion would g, exist. The minimum pressure of %![psig is well below the expected pressure of approximately 1450 psig while still ensuring sufficient pressure for rapid control rod insertion. The 7 day Frequency has been shown to be acceptable through operating experience and takes into account indications available in the control room.

REFERENCES 1. NEDE-24011-P-A-US, General Electric Standard Application for Reactor Fuel, Supplement for United States, February 1991.

2. Letter from T. Pickens (BWROG) to G.C. Lainas, NRC,

" Amendment 17 to General Electric Licensing Topical Report NEDE-24011-P-A," August 15, 1986.

PBAPS UNIT 3 B 3.10-36 Revision No. 0

.

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