ML20128C361

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Proposed Tech Specs Re CRD & CRD Scram Accumulators
ML20128C361
Person / Time
Site: Brunswick  Duke Energy icon.png
Issue date: 01/25/1993
From:
CAROLINA POWER & LIGHT CO.
To:
Shared Package
ML20128C076 List:
References
NUDOCS 9302030406
Download: ML20128C361 (20)
v • d • e


Text

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, a ENCLOSURE 4 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS 1 AND 2 NRC DOCKET NOS. 50-325 & 50 324 OPERATING LICENSE NOS, DPR 71 & DPR 62 RJOUEST FOR LICENSE AMENDMENT CRD AND CRD SCRAM ACCUMULATORS PROPOSED TECHNICAL SPECIFICATION CHANGES UNIT NO.1 1

l 9302030406 DR 930125 ADOCK 05000324 PDR

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' REACTIVITY CONTROL SYSTEMS LlHIT!NG CONDITION FOR OPERATION (Continued)

ACTION! (Continued)

2. If the inoperable control rod (s) it inserted:

a) Within one hour disarm the associated directional control valves either

1) Elect rically, or
2) Hydraulically by closing the drive water and exhaust water isolation valves.

b) Otherwise, be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, BOO [ % e pron yso,2 of 5pt.;hb.h% 3.M orL nst AMWaTKD

c. With more inan 5 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 byt*  !

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4.1.3.1.2 ~ All withdrawn control rods not required to have their directional control valves disarmed electrically or hydraulically shall be demonstrated OPERABLE by moving each control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 notchs

a. 'At least once per 7 days when above the preset power level of the RWM I and l.

i

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 l l RWM and any control rod is immovable as a result of excessive l 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4.1.3.1.3 All withdrawn control rods shall be determined OPERABLE by demonstrating the scram discharge volume drain and vent valves'0PERABLE, when-the reactor protection system logic is tested per Specification 4.3.1.2, by verifying that the drain and vent valvest

a. Close within 30 seconds after receipt of_a signal for control rods to

, cram, and

b. Open when the scram signal is reset or the scram discharge volume trip is bypassed.
  • These valves may be closed intermittently f or testing under administrative control.

BRUNSWICK - UNIT 1 3/4 1-4 Amendment No. 144 1

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-REACTIVITY CONTROL 3YSTEMS CONTROL ROD SCRAM ACCUMULATORS LlHITING CONDITION FOR OPERATION 3.1.3.5- All control rod scram accumulators shall be OPERABLE.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2, and 5*.

. .g.s . L. .

"" ACTION:

~ _

a. 'In OPE TIONAL CONDITION ' or 2 with one c 6 trol rod scram a c c ur. lator inoperable, he provisions of pecification 3.0 4.are n'ot app icable and operat'4n may continue, p ovided that with' 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />st'

. The inoperabl accumusator is re ored to OPERABL status, or

'2. The control rod associated wit the inoperable ceumulator is declared y' 1 operable, and the equirements of S ecification 3.1.3.1 tre satisfied.

3. And, within the prese power level of e RWH, the requ rements of Specifi ation 3.1.4.1.d re also satisfied.

Otherw' e, be in at least 10T SHUTDOWN wit in- the next 12 hou .

b. In 0 ERAT 10NAL CONDITIO 5* with a withy wn control rod se, ac ulator inoperabl , fully insert tVe affected controljfod and e} ctrically disarm edirectionalcdntrolvalveswithjdonehour.

The provisions of Specification 3.0.3 are not applicable.

l -

SURVEILLANCE REQUIREHENTS 4.1.3.5 The control rod scram ' accumulators shall be determined OPERABLE

a. At least once per 7 days by verifying that the pressure and leak detectors are not in the alarmed condition, and
b. At least once per 18 months by performance of at
1. CHANNEL FUNCTIONAL TEST of the leak detectors, and
2. CHANNEL CALIBRATION of the pressure detectors.

1)ELEd hfad arruMD Y

BRUNSWICK - UNIT 1 3/4 1-8 Amendment No. 144

PROPOSED CHANGES TO SPECIFICATION 3.1.3.5- ,

ACTION:

a. In OPERATIONAL CONDITIONS 1 or 2:
1. Below the preset power level of the RWM, the requirements of Specification .-

3.1.4.1.d are satisfied, and

2. With one control rod scram accumulator inoperable and -

a) reactor steam dome pressure a 950 psig, with!n 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> either:

1) Restore the control rod scram accumulator to OPERABLE status, or
2) Declare the associated control rod inoDerable, and satisfy the requirements of Specification 3.1.3.1.

b) reactor steam dome pressure < 950 psig, within 8 Lours either:

1) Restore the control rod scram accumulator to OPERABLE status, or
2) Fully insert and declare the associated control rod inoperable, and satisfy the requirements of Specification 3.1.3.1.
3. With two or more control rod scram accumulators inoperable, and a) reactor steam dome pressure a 950 psig, immediately verify charging water header preseure a 940 psig, and, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, either:
1) Restore all control rod scram accumulators to OPERABLE status,0:
2) Declare the associated control rods inoperable and satisfy the requirements of Specification 3.1.3.1; b) reactor steam dome pressure < 950 psig, immediately verify charging water header pressure a 940 psig, and, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, either:
1) Restore all control rod scram accumulators to OPERABLE status, or
2) Fully insert and declare the associated control rods inoperable and satisfy the requirements of Specification 3.1.3.1.

4 The provisions of Specification 3.0.4 are not applicable.

4

~

PROPOSED CHANGES TO SPECIFICATION 3.1.3.5 (CONTINUED)-

b, in OPERATIONAL CONDITION 5':

1. With the scram accumulator for one or more withdrawn control rod (s) inoperable, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> fully insert the affected control rod (s) and electrically disarm the directional control valves. The provisions of Specification 3.0.3 are not applicable.

iy ,

p REACTIVITY 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 tKme 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 ba 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 rod drive mechanism could be a generic 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 inoperable for other reasons _are permitted to be taken out of service provided that those in the non-fully-inserted position- I are consistent with the SHUTDOWN MARCIN requirements.-

- 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 shut down for investigation and resolution of the problem.

f The control-rod system is analyzed to bring-the reactor subcritical at a rare 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 that-the negative reactivity rates resulting from the scram _with the average response of all the drives as given in the spocifications, 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.

Con 1 rod [ inopera e and ation3[s-vithinoerableacc ulators

.3.1 t en applies. This pre pte entsdeclar a p een of i opera e Spe/ci acc lators hat wou result inj ess reae vity in tion-k, g

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B 3/4 1-2 BRUNSWICK - UNIT 1 Amendment No. 131

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.c REACTIVITY CONTROL SYSTEM Ali^p DGL W ,r .

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CONTROL RODS (Continued) r .on a s, dam thanj has been a alyzed even t ough control ds with ipoperabi accupulators pay still b inserted vi normal driv water pres Gre.

{ Operability 4f the ac .ulator ensu s that'ther as a means vailab to ,

\ dnsert t . control 4ds even und the most upfavorable d ressuri a) tion of I Q he reac ors. __ _

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 criticalit y af ter 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 crimary 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 so frequent as to cause excessive wear on the system components.

3/4.1.4 CONTROL ROD PROGRAM 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 10% of RATED THERMAL POWER, there is no possible l 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 RWM to be OPERABLE when THERMAL POWER is less than 10% of RATED THERMAL POWER-provides adequate control.

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).

BRUNSWICK - UNIT 1 B 3/4 1-3 Amendment No. - 144

PROPOSED BASES fantrglRod Ooerability 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 Iroperable control rod is demonstrated by inserting the control rod at least one notch by drive w' r pressure within the normal operating rango. Inserting a control rod ensures the shutdown an ' scram capabilities are not adversely aff acted. Adequate separation of inoperable withdrawn control rods (inoperable for reasons other than being immoveable or untrippable) is required to ensure consistency with the scram reactivity function assumed in the reload licenting 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.S, 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 eod operability specifications listed above (Reference 8).

I

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PROPOSED BASES Control Rod Scram Accumulators OPERABILITY of the control rod scram accumulators is required to ensure that adequate scram insertion capability exists.' Under normal reactor operating pressure, both the scram accumulator and reactor watrr pressure are available to jointly scram the drive. The scram accumulator is primarily used to scram the drive during plant startup or when the reactor pressure is less than 950 psig (Reference 1); therefore, ACTION statements for inoperable control rod scram accurniators in this specification are based on the status of the reactor (i.e., reactor steam dome pressure being above or below 950 psig).

The OPERABILITY of the individual scram accumulators is based on maintaining adequate:

accumulator pressure. Control rods with OPERABLE scram accumulators are considered to capable of meeting the required scram insertion times whenever the charging header pressure is sufficient' to keep the individual scram accumulators charged. The charging water header pressure required to ensure minimum scram performance is met is 940 psig (Reference 1); therefore, ACTION statements for inoperable accumulators are also based on ensuring the charging water pressure is 2 940 psig.

Inoperable accumulators are either repaired within defined time frames or the control rods.

associated with the inoperable accumulator are declared inoperable. Specification 3.1.3.1 is then applied for inoperable control rods. This ACTION prevents a pattern of inoperable accumulators that would result in less reactivity insertion on a scram than has been analyzed, even though control rods with inoperable accumulators may still be inserted with normal drive water pressure (at

  • normal reactor operating 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 reactor.

ACTION 3.1.3.5.a With a single control rod scram accumulator inoperable and the reactor steam dome pressure 2 950 psig, the control rod will still scram at the reactor operating pressure; however, since the accumulator provides extra drive pressure over the initial portion of the stroke, some degradation in the scram insertion time may occur. The accumulator must be restored to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, or the associated control rod is declared inoperable. The requirements of Specification 3.1.3.1, action b would then apply. This ACTION ensures both methods (reactor pressure and accumulator pressure) are available to insert the control rod or results in additional ACTIONS being

' performed on the inoperable control rod, consistent with the intent of the governing control rod .

specification.

With a single control rod scram accumulator inoperable and the reactor steam dome pressure

< 950 psig, the control rod may not fully insert during a scram following a depressurization event

' or at low reactor pressures. The associated control rod is either restored to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or is fully inserted and declared inoperable. The requirements of Specification 3.1.3.1, action b would then apply. This ACTION ensures that the accumulator is returned to OPERABLE status or the negative reactivity of the control rod is ensured with the control rod inserted (and disarmedh 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 for a single control rod with an inoperable accumulator, based on the large number of control rods available to provide the immediate scram function and the low probability of a DBA or transient occurring while the affected accumulator is

c w ,+ i J

- inoperable.-

Multiple inoperable accumulators may be indicative of a generic concern; therefore, with two or=

~

more control rod accumulators inoperable, adequate pressure must be verified in the charging water header; Without adequate charging water pressure, the control rod insertion capability may be severely degraded; therefore, charging water header verific'ation is a precursor to continued - <

operation with multiple accumulators inoperable.

With the reactor steam dome pressure d 950 psig, control rods with inoperobie accumulators will stillinsert with reactor pressure but may not satisfy the required scram times. The multiple inoperable scram accumulators must be restored to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, of the associated control rods are declared inoperable and the requirements of Specification 3.1.3,1, action b then apply. ACTION b of Specification _3.1.3.1 ensures that there is a means available to insert the control rod or result in the affected control rod being fully inserted and disarmed, thereby satisfying its intended function. The allowed completion time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is reasonable, based on the ability of only the reactor pressure to scram tho control rods and the low probability of a DBA or transient occurring while the affected accumulators are inoperable.

With the reactor steam dome pressure < 950 psig, the function of the accumulators in providing the inserting force becomes t' x" more important. Therefore, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, all control rods associated with inoperable acco.uulators must be verified to be fully inseded and declared inoperable.- Withdrawn control rods with inoperable accumulators may fail to scram under these low pressure conditions. The allowed Completion Time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is reasonable; considering the low probability of a DBA or transient occurring during the time that the accumulator is inoperable.

ACTION 3.1.Alb 10 CFR 50, Appendix A, General Design Criteria 26, requires that one of the reactivity controls systems be capable of holding the reactor core subcritical under cold conditions; The CRD System is the system which performs this function. This specification ensures that, during OPERATIONAL CONDITION 5, the accumulator associated with each withdrawn control rod remains OPERABLE.

This capability ensures that in the event of a scram; the withdrawn control rods willinsert and provide the required negative reactivity to maintain the reactor subcritical. Because of existing controls within Specifications 3.9.10.1 and 3.9.10.2, provisions of Specification 3.1.3.5.b are not applicable to control rods removed per the guidance of these specifications.

REFERENCES

1. GE Report No. RDE-47-1290
2. Updated FSAR, Section 15
3. NEDO-21231, " Banked Position Withdrawal Sequence," Section 7.2, January 1977.
4. 10 CFR 50, Appendix A, GDC 26, GDC 27, GDC 28 and GDC 29
5. Updated FSAR, Section 4.2
6. Updated FSAR, Section 3.1
7. Updated FSAR, Section 4.6
8. LLA-92-069, General Electric Technical Evaluation - Brunswick Technical Specification Change for LCO 3.1.3.1, November 5,1992.

-7 .

i ENCLOSURE 5 .-

BRUNSWICK STEAM ELECTRIC PLANT, Ue' int NOS.1 AND 2 *

- NRC DOCKET NOS. 50-325 & 50-324 OPERATING LICENSE NOS. DPR 71 & DPR 62 REQUEST FOR LICENSE AMENDMENT CRD AND CRD SCRAM ACCUMULATORS-PROPOSED TECHNICAL SPECIFICATION CHANGES UNIT NQJ "k

q'; o _ g.

'.J REACTIVITY CONTROL' SYSTEMS LiMITl NC CONDITION l'OR' OPERATION - (ConL inued)'

ACTIONI (Continued)

2. If thelinoperable. cont rol rod (s)~ is-insertedt:

a) - Within one hour disarm the associated directional cont rol valves either

1) Elect rically, or
2) Hydraulically-by closing the drive water and exhaust water

.DO i sola t ion val ve s. _

f it) Ot he rw i s ed_in . a t . I c asL11QIJililjTMWN_wi t hi n - th next 12-hours.- -

M L The p u,a u ns cf S eesh f u H w 3.6+ are ec,t afflic D

c. With more'than 5 controt rods inoperable, De in at Icast ilOT 5110TDOWN ,

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 byt*

a. Verifying each valve to be open,
b. Cycling each valve at least one complete cycle of. f ull travel.-

4.1.3.1.2 All withdrawn control rods not required to have their directional control valves disarmed electrically or hydraulically shall be demotistrated 3: OPERABLE by moving each control rod at least one notcht

a. At-least once per 7 days when above the preset power-level.of the~RWM-and -ll
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 l preset . power level of the- i RWM and any cnntrol rod is immovable as a result of excessive l.

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'0PERABLE,.when the reactor protect' ion. system logic is tested per Specification 4.3.1.2, by -

verifying that the drain and vent valvest-

a. Close within 30 seconds af ter receipt of a signal . f or control- rods to scram, and
b. Open when the scram signal is reset or the scram discharge volume t rip -is bypassed.
  • These valves may be closed intermittently for testing under administrative control.

BRUNSWICK - UNIT 2 3/4 1-4 Ame ndment No.-175

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  • -  :/

REA_CTIVITY CONTROL SYSTEMS- //ACb

APPLICABILITY: OPERATIONAL CONDI ONS 1, 2, and 5*.-

ACTION:

./ _ _ -

a. In OPERATIONAt' CONDITION 1 or 2 wik e cot. trol rod ser in a c c umul atst i no pe ra bl e , the pr pisions of Specificati 3.0.4 are not applic b'fe and operation ma ntinue, provided within 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />st _

The inoperable ac

~

1 lasor is restored to PERABLE status, or k

'/

/. 2. The control d associated with the i perable accumulator declared in perable, and the t equir tent s of Specificatl 3.1.3.1,dre satir.fied.

s-P j

3. An);ifwithinthepreset power level of = t he RWM, e yt>quirement s of Specif icat ien 3.1.4.1.d are al s satisfied.

Qt wise, be in at least il IUTDOWN within th next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

/

f in OPERATIONAL CONDITION.

  • with a withdrawn ontrol rod scrar accumulator inoperable /f ully insert the a ected control to and j electrically disarm phe directional cont valves within e hour./

The provisions of Specification 3,0.3 are not a ppli ca bl e. /

/

SURyFILLANCE REQUIREMENTS 4.1.3.5 The control rod scram accumulators shall be determined OPERABLE:-

a. At least-once per 7 days by verifying that the pressure and leak detectors are not in the alarmed condition, and
b. At least once per 18 months by perf ormance of a:
1. CHANNEL FUNCTIONAL TEST of the leak detectors, and
2. CHANNEL. CAllBRATION of the pressure detectors.

BRUNSWICK - UNIT 2 3/4 1-8 Amendment No. 175

. u .

PROPOSED CHANGES TO SPECIFICATION 3.1.3.5 l P

ACTION:

a. In OPERATIONAL CONDITIONS 1 or 2:

. Delow the preset power level of the RWM, the requirements of Specification 3.1.4.1.d are satisfied, and

2. With one control rod scram occumulator inoperable and a) resctor steam dome pressure a 950 psig, within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> either:
1) Restore the control rod scram secumulator to OPER ADLE status, or
2) Declare the associated control rod inoperable, and satisfy the requirements of Specification 3.1.3.1.

td reactor steam dome pressure < 950 psig, within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> either:

1) Restore the control rod scram accumulator to OPERABLE status,' or
2) Fully insert and declare the associated control rod inoperable, and -

satisfy the requirements of Spec!fication 3.1.3.1.

3. With two or more control rod scram accumulators inoperable, and a) rebetor steam dome pressure h 950 psig,immediately verify chargin0 water header pressure a 040 psig, and, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, either:
1) Restore all control rod scram accumulators to OPERABLE status, or
2) Declare the associated control rods inoperable and satisfy the requirements of Specification 3.1.3.1.

b) reactor steam dome pressure < 950 psig, immediately verify charging water header pressure t 940 psig, and, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, either:

1) Restore all control rod scram accumulators to OPERABLE status, or 21 Fully insert and declare the associated control rods inoperable and satisfy the requirements of Specification 3.1.3.1.
4. The provisions of Specificadon 3.0.4 are not applicable.

l

PflOPOSI:D CHANGES TO SPEClflCATION 3.1.3.t; 'CO'dTINUED)

b. In OPERATIONAL CONDITION 5*:
1. With the scram accumulator for one or more withd dWn control rod (s) inoperable, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> fully insert the affected control rod (s) and electrically disarm the directional control valves.
2. The provisions of Specification 3.0.3 are not applicablo.

1 l

1

a ,  !

REACTIVITY CONTROL SYSTEMS 3ASES _,  ;

CONTROL RODS (Continued)  !

potential effects cf the rod ejection accident are limited. The ACTION stat ments permit varlations from the basic requirements but at the same time ..

Impose more restrictive criteria for continued operation.- A Limitation on i~

inoperable rods is set such that the risultant 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 l drives will be investigated on a timely basis.

Damage within the control rod drive mechanism could be a generic problems therefore, with a control rod immovable because of excessive friction or e 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 operatio6 with a~~1arge nun.bu of inoperable control. rods.

Control rods that are inoperable for other reasons are rarmitted to be-taken out of service provided that thos6 in the non-fully-inserted position -

are consistent with the SHUTDOWN MARCIN requirements.

)

[. The number of control rods permitted to be inoperable could be more-than i

/ 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 shut down for investigation and resolution of the problem.

s The control rod system is analyzed to bring the reactor subcritical_at a rate f ast enough to prevent the MPCR from becoming less than the Safety Limit: .l HCpR of Specification 2.1.2 during the limiting power transient. analyzed in. t Section 14.3 of the FSAR. This analysis shows that. the negative reactivity l

rates resulting from the scram with the average response.of all.the drives as given in the specifications,' provide the required protection and NCpR 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 periode of

~

time with a potentially serious problem.

ntrolpoirvi ihoper ble accu ulators re dect.afed ino raole d Sp9 ificatjan 3.1.)f.1 then applies. This pr vents a ffattern f inop able -

peu.nulatges thap'would r suit in ess_reag ivity insertion

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BRUNSWICK a UNIT 2 B 3/4 1-2_. Amendment No._161 'I a

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REACTIVITY CONTROL SYSTEM g-f - hftACE g 77(

BASES

.J [>prw u&O ,

CONTROL RODS (Continued)

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f on a scydm ~than ha been anal ed even thoupd c ntrol 4ds with

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operab/e ) i L accu fators may still be i rted with npfmal drive ater pres are. / I l

Op bility of he accumul orensures)nattherej a means vailab to i ert the c trol rods venunderthe'mostunfadrabledergessuri tion f he reacto .

Control rod coupling integrity is required to ensure compliance with the analysis of the rod drop accident i n t i. i% R . The overtravel-position feature provides the only positive means of determining that a rod is properle 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 muet 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 f orce to rapidly eject a drive housing.

The required surveillance intervals are adequate to determine that the rods are OPERABLE and not so frequent as to cause eMeessive wear on the system components.

3/4.1.4 CONTROL ROD PROGRAM CONTROLS i

Control rod withdrawal and insertion sequences are established to assure ,

that the maximum in sequence individual control rod or control rod stgments

~

which are withdrawn at any time during the f uel cycle could not be worth enough to result in a peak fuel enthalpy 'reater g 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 10% of RATED THERHAL POWER, there is no possible- l 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 RWH to be OPERABLE when THERHAL POWER is less than 10% of RATED THERHAL POWER provides adequate control .

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 (Ref erence 4).

-BRUNSWICK - UNIT 2 B 3/4 1-3 Amendment No. 175

PROPOSED BASES Control Rod Ooerability With one or more withdrawn control rods Inoperable for reasons other than being stuck, operation may continue, provided within one hour, either al the inoperable withdrawn control rod (s) are fully inserted and disarmed felectrically or hydraulically), or b) the inoperable co.itrol 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 dsmonstrated 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 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 cL31ng 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, 3.1.3.0,' 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 er %ol rods and is -

consistent with the individual control rod operability specifications listed 'sove (Reference P,1.

i PROPOSED BASES i

Control Rod Scram Accumulators OPERABILITY of the control rod sciam accumulators is required to ensure that adequate scram insertion capability exists. Under normal reactor operating pressure, both the scram accumulator >

and reactor water pressure are available to jointly scram the drive. The scram accumulator is primarily used to scram the drive during plant startup or when the teactor pressure is less than i 950 psig (Reference Ib therefore, ACTION statements for inoperable control rod scram - _.

accumulators in this specification are based on the status of the reactor (l.c., reactor steam dome .

pressure being above or below 950 psig).  !

The OPERABILITY of the individual scram accumulators is based on maintaining adequate accumulator pressure. Control rods with OPERABLE scram accumulators are considered to capable ,

of meeting the required scram insertion timos whenever the charging header pressure is sulficient to keep the individual scram accumulators charged. The charging water header pressure required to ensure minirnum scram performance is met is 940 psig (Reference ih therefore, ACTION- ,

statements for inoperable accumulators are also based on ensuring the charging water pressure is l k 940 psig. ,

inoperable accumulators are either repaired within defined time immes or the control rods associated with the Inoperable accumulator are declared inoperable. Specification 3.1.3.1 is then applied for inoperable control rods. This ACTION prevents a pattern of inoperable accumulators -

that would result in less reactivity insertion on a scram than has been analyzed, even though  ?

control rods with inoperable accumulators may still be inserted with normal drive water pressura (at .  :

normal reactor operating pressure). Operability of the accumulator ensures that there is a meats available to insert the control rods even under the most unfavorablo depressurization of the reti; tor. ,

ACTION 3.1.3.5.g With a single control rod scram accumulator inoperablo and the reactor steam dome pressure ;

a 950 psig, the control rod will still scram at the reactor operating pressure; however, since ihe accumulator provides extra drive pressure over the initial portion of the stroke, some degradation in the scram insertion time may occur. The accumulator must be restored to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, or the associated control rod is declared inoperable. The requirements of Specificathn >

3.1.3.1, action b would then apply. This ACTION ensures both methods (reactor pressure ard -

accumulator pressure) are ava2able to insert the control rod or results in additional ACTIONS %eing performed on the inoperable control rod, consistent with the intent of the governing control rpd sper'irication.

With a single control rod scram accumula inoperable and the reacar steam dome pressuro;

< 950 psig, the control rod may not full nsert during a scram following a depressurization ovent' or at low reactor pressures. The assocl# sd control rod is either restored to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or is fully inserted and d( .lared inoperable. The requirements of Specification 3.1.3.1, action b would then apply. This ACTION ensures that the accumulator is returned to-OPERABLE status or the negative reactivity of the control rod is ensured with the control rod ;

inserted (and disarmed).

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 for a single control rod with an inoperable accumulator, based on the large number of control rods available to provide the immediato scram .

function and the low probability of a DBA or transient occurring while the affected accumulator is

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e o a inoperable.

Multiple inoperable accumulators may be indicative of a generic concern; therefore,' with two or ,

more control rod accumulators inoperable, adequate pressure must be verified in the charging water header. Without adequate charging water pressure, the control rod insertion capability may be ,

severely degraded; therefore, charging water header verificatbn is a precursor to continued operation with multiple accumulators inoperable. j With the reactor steam dome pressure a 950 psig, control rods with inoperable accumulators will .

stillinsert with reactor pressure but may not satisfy the required scram times. The multiple inoperable scram accumulators must be restored to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, or the associated control rods are declared inoperable and the requirements of Specification 3.1.3.1,_ '

action b then apply. ACTION b of Specification 3.1.3.1 ensures that thee is a means available to insert the control rod or result in the affected control rod being fully inserted and disarmed, thereby _ l satisfying its intended function. The allowed completion time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is reasonable, based on the ability of only the reactor pressure to scram the control rods and the low probability of a DBA of transient occurring while the affected accumulators are inoperable.

With the reactor steam dome pressure < 950 psig, the function of the accumulators in providing the inserting force becomes much more important. Therefore, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, all control rods associated with Inoperable accumulators must be verified to be fully inserted and declared inoperable. Withdrawn control rods with inoperable accumulators may fall to scram under these low press.ure conditions. The allowed Completion Time of I bour la reasonable, considering the low probability of a DBA or transient occurring during the time that the eccumulator is inoperable.

ACTION 3MJd2 10 CFR 60, Appendix A, General Design Criteria 20, requires that one of the reactivity controls systems be capable of holding the reactor core suberitical under cold conditions. The CRD System is the system which performs this function. This specification ensures that, during OPERATIONAL CONDITION 5, the accumulator associated with each withdrawn control rod remains OPERADLE.

This capability ensures that in the event of a scram, the withdrawn control rods willinsert and provide the required negative reactivity to maintain the reactor subcritical. Because of existing controls within Specifications 3.9.10.1 and 3.9.10.2, provisions of Specification 3.1.3.5.b are not applicable to control rods removed per the guidance of these specifications.

REFERENCES

1. GE Report No. RDE 471290
2. Updated FSAR, Section 15
3. NEDO 21231, ' Banked Position Withdrawal Sequence,* Section 7.2, January 1977.
4. 10 CFR 50, Appendix A, GDC 20. GDC 27, GDC 28 and GDC 29
5. Updated FSAR, Section 4.2
6. Updated FSAR, Section 3.1
7. Updated FSAR, Section 4.6
8. t.LA 92 069, General Electric Technical Evaluation Brunswick Technical Specification Change for LCO 3.1.3.1, November 5,1992.
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