ML20044F162

Proposed Amend PCOL-92/09 to License NPF-29,removing Unnecessary Operability Requirements for IRMs & APRMs During Plant Shutdown Conditions.Ts Changes Follow NUREG-1434, Rev 0 Requirements

ML20044F162
Person / Time
Site:	Grand Gulf
Issue date:	05/20/1993
From:	Hutchinson C ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20044F164	List: ML20044F162 ML20044F166
References
RTR-NUREG-1434 GNRO-93-00049, GNRO-93-49, NUDOCS 9305270094
Download: ML20044F162 (14)

Text

A k . T Ent.ergy g-aq"*"*'"=-

~ Operations .;;gy <

May 20, 1993

• U.S. Nuclear Regulatory Commission Mail Station P1-37 Washington, D.C. 20555 Attention: Document Control Desk

Subject:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Operability Requirements for the Intermediate Range Monitors and Average Power Range Monitors during Modes 3,4, and 5 Proposed Amendment to the Operating License (PCOL-92/09)

Reference:

NUREG-1434, Revision O of the Improved Standard Technical Specifications.

GNRO-93/00049 Gentlemen:

Entergy Operations,Inc. by this letter is submitting a proposed amendment to the Grand Gulf Nuclear Station (GGNS) Operating License. These Technical Specification (TS) changes follow the guidance of NUREG-1434 Revision O including subsequent changes agreed to by the NRC and the Owners' Group. The requested changes remove unnecessary operability requirements for the Intermediate Range Monitors (IRMs) and Average Power Range Monitors (APRMs) during plant shutdown conditions. These changes to the Technical Specifications are requested prior to the start of the sixth refueling outage currently scheduled for October 1993, since removing these requirements will assist in the scheduling of maintenance activities during the outage.

Attachment 2 of this letter provides a detailed description of the proposed TS changes and justification for the changes. Attachment 2 also details the basis for the Entergy Operations, Inc. determination that the proposed amendment involves no significant hazards considerations based on the guidelines presented in 10CFR50.92.

The affected TS pages marked up indicating the proposed changes are included as Attachment 3.  !

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May 20, 1993

- GNRO-93/00049 ,

Page 2 of 3 In accordance with the provisions of 10CFR50.4, the signed original of the requested amendment is enclosed. This amendment request has been reviewed and accepted by the Plant Safety Review Committee and the Safety Review Committee.

Yours truly,  ;

A f7 '

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./ e t C. R. utchinson ,

Vice President, Operations GGNS l BSF I attachments: 1. Affirmation per 10CFR50.30  ;

2. GGNS PCOL-92/09  :

3. Mark-up of Affected Technical Specification Pages  !

4. Sample Proposed Technical Specification Pages cc: Mr. R. H. Bernhard (w/a)  !

i Mr. H. W. Keiser (w/a)

Mr. R. B. McGehee (w/a) ,

Mr. N. S. Reynolds (w/a)

Mr. H. L. Thomas (w/o) ,

Mr. Stewart D. Ebneter (w/a) -

Regional Administrator U.S. Nuclear Regulatory Commission j Region il 101 Marietta St., N.W., Suite 2900 ,

Atlanta, Georgia 30323 i Mr. P. W. O'Connor, Project Manager (w/2) [

Office of Nuclear Reactor Regulation l U.S. Nuclear Regulatory Commission {

Mail Stop 13H3 l Washington, D.C. 20555  :

Dr. Alton B. Cobb (w/a) f State Health Officer l State Board of Health '

P.O. Box 1700 .

Jackson, Mississippi 39205 i i

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• Attachm:nt 1 to GNRO 93/00049

. BEFORE TEE Page 1 of 1. .

l UNITED STATES NUCLEAR REGULATORY COMMISSION l l

LICENSE NO. NPF-29 l

DOCKET NO. 50-416 ;s i

IN TEE MATTER OF

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i MISSISSIPPI POWER & LIGHT CCBEPANY and SYSTEK ENERGY RESOURCES, INC.

and SOUTE MISSISSIPPI ELECTRIC POWER ASSOCIATION and 3 ENTERGY OPERATIONS, INC.

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- AFFIRMATION I, C. R. Butchinson, being duly sworn, state that I am Vice President,  !

Operations GGNS of Entergy Operations, Inc.; that and on - behalf of Entergy South' Mississippi

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Operations, Inc., System . Energy Resources, Inc.,

Ulectric Power Association I an authorized by Entergy Operations, Inc. to j cign and file with the Nuclear Regulatory Commission, this application for- j amendnent of the Operating License of the Grand Gulf Nuclear Stations that I l oigned this application as Vice President, Operations . GGNS of Entergy 'l Operations, Inc.; and that the statements made and the matters set forth therein are true and correct to the best of my knowledge, information and i

-belief.

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C. R. Butchinson l i

STATE OF MISSISSIPPI -6 i

COUNTY OF CLAIBORNE i SUBSCRIBED AND SWORN TO before me, a Notary Public, in and for the County and? . ;

State above named, this Sei day of- m ,vj- , 1993.-  ;

(SEAL)

/-

hw 0$ne//J bMsake 4 Notary Public O i

i My commission expires: j Wy Commission Expires November 11,1996 l

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GGNS PCOL 92/09 ,

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Attachment 2 to GNRO-93/00049 Page 2 cf 11 i

A. SUBJECT PCOL-92:09 Operability Requirements for the Intermediate Range Monitors and Average Power Range Monitors dunng Modes 3,4, and 5 Affected Technical Specifications:

1. Table 3.3.1-1, Reactor Protection System Instrumentation, items 1.a 1.b, 2.a. and f 2.d, pages 3/4 3-2 and 3/4 3-5.  ;

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2. Table 4.3.1-1, Reactor Protection System instrumentation Surveillance Requirements, items 1.a.1.b. 2.a. and 2.d, pages 3/4 3-7 and 3/4 3-8. .

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3. Table 3.3.6-1, Control Rod Block Instrumentation,-item 2, item 4 and Note (d), f pages 3/4 3-53 and 314 3-54.

4 Table 3.3.6-2, Control Rod Block Instrumentation Setpoints, item 2 and item 4, pages 3/4 3-55 and 3/4 3-55a. ,

5. Table 4.3.6-1, Control Rod Stock instrumentation Surveillance Requirements, item

2. Item 4 and Notes f, g, and h, pages 3/4 3-56 and 3/4 3-57.

6. Limiting Condition For Operation 3.10.3, Shutdown Margin Demonstrations, page  ;

3/4 10-3.

l B. DISCUSSION AND JUSTIFICATION Currently the Grand Gulf Nuclear Station (GGNS) Technical Specifications (TSs) requite that the Average Power Range Monitors (APRMs) and Intermediate Range Monitors (IRMs) be  ;

operable in Operational Conditions (OPCONs) 3,4 (IRMs only) and 5 as part of the Reactor  !

Protection System (RPS) and OPCON 5 as part of the Control Rod Block System. This j requirement restricts outage maintenance activities and requires surveil 4nce and  ;

maintenance necessary to maintain system operability. The primary reast, ' for removing i these operability requirements is to reduce unnecessary outage schedulinh restrictions by l allowing maintenance activities to be performed on the Local Power Ranr,e Monitors -

(LPRMs) strings (which input to the APRM circuitry) and IRMs in conjun.; tion with other i refueling activities, in addition, the proposed change will preclude the need for testing and maintenance to maintain system operability when the unit is shutdown (i.e., OPCONs 3,4, and 5), except when any control rod is withdrawn from a fueled cell for the IRMs or v.t.en APRM operability is required during shutdown margin demonstrations.

The changes requested by this submittal are consistent with NUREG-1434, Revision 0, j

" improved Standard Technical Specifications," (Reference 1) although editorial changes j have been made in the presentation of the requirements to maintain consistency with the l current GGNS Technical Specifications. This requested change also relocates the l operability requirements for the APRMs and the IRMs associated with the Control Rod Block j System to be controlled by plant procedures consistent with NUREG-1434. J l

The changes requested for the RPS function of the IRMs are consistent with the I requ:rements contained in NUREG-1434 in only requiring the IRMs to be operable when the 1 unit is shutdown if a control rod is withdrawn from a fueled cell. The changes requested j for the APRMs are consistent with NUREG-1434 in removing the operability requirements j

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Attachment 2 to GNRO-93/00049  !

Page 3 of 11 for the APRMs as part of the RPS in OPCON 3 and restricting the operability requirements i

for the APRMs as part of the RPS during OPCON 5.  :

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The requested change to the APRM operability requirements differs from the requirements i identified in NUREG-1434 Revision 0 in that NUREG-1434 identifies that the neutron flux j and inoperative trips of the APRMs should be operable in OPCON 5 any time that a control  ;

tod is withdrawn from a fueled cell. The requested Change would only require that these i APRM trip functions be operable during the shutdown margin demonstrations allowed by TS 3.10.3. This modification in APRM operability requirements has been previously requested f

j by another utility and granted by the NRC (Reference 21. The Owners' Groups Technical  !

Specification Improvement Committee proposed a line item improvement to NUREG-1434 i consistent with the requested APRM operability requirements in the industry /NRC meeting l

in Dallas on 2/19/93. This improvement was accepted by the NRC in the Industry /NRC  :

meeting in New Orleans on 3/18/93.

l Entergy Operations has determined that revising the IRM and APRM operability ,

requirements while the plant is shutdown is acceptable because the IRMs and APRMs are .;

not necessary for safe operation since there are sufficient ievels of protective controls ,

4 designed to prevent inadvertent criticality and fuel damage during refueling. The Source ,

Range Monitors (SRMs), Refueling Interlocks (Ris), and plant procedures, each provide #

protection which maintains the needed defense-in-depth and, therefore, precludes the need {

for the IRMs and APRMs to be operable when the unit is shutdown. However, the i requirement for the IRMs to be operable whenever a control rod is withdrawn from a fueled  !

cell and the requirement for the APRMs to be operable during a shutdown margin demonstration when the mode switch is in Startup as allowed by TS Section 3.10.3 will remain in effect (TS Section 3.10.3 is a Special Test Exception which allows operators to  !

perform a shutdown margin demonstration.).

To assess the impact of the proposed change on safety and the design bases accidents, j Entergy Operations examined those systems and mechanisms which contributed to safe operation while the plant is shutdown. This examination focused on refueling operations  :

since during OPCONs 3 and 4 fexcept for a single control rod removed as allowed by TS l 3.9.10.1) all rods are required to be inserted into the core and the RPS and control rod '

d block functions of these instruments could have no affect ors core reactivity during those  ;

conditions. The current IRM and APRM operability requirements were found to be unnecessary to maintain the needed defense-in-depth for safe operation. A discussion of  !

this examination follows.

I System Description  ;

The Neutron Monitoring System (NMS) is composed of the following subsystems: SRM, j IRM, LPRM, APRM, and Traversing incore Probe (TIP). The purpose of the SRM, IRM, and )

APRM subsystems is to monitor local and core average neutron flux levels and provide trip i signals to the RPS and control rod block system as required. The NMS also provides local

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and core average power information to the reactor operator.  ;

The SRM subsystem is composed of six detectors that are inserted into the core during l shutdown conditions. The SRMs are required by TS to be operational in OPCON 5. This  !

, requirement will not be affected by the proposed change. During refueling operations, the  !

plant operators use the SRMs to ensure that neutron flux remains within an acceptable  !

range. Also, plant operators can monitor the SRMs for increases in neutron flux which may f indicate that the reactor is approaching criticality.  !

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Attachment 2 to GNRO-93/00049 Page 4 of 11 The IRM subsystem is composed of eight incere detectors that are inserted into the core.

The IRMs are five-decade instruments with ten ranges that are ranged up during normal power increases. The IRMs are designed to monitor neutron flux levels at a local core location and provide protection against local criticality events caused by control rod withdrawal errors. The IRMs monitor neutron flux levels from the upper portion of the SRM range to the lower portion of the APRM range. In terms of rated reactor power, the IRMs .

range from about 10E-4% of full reactor power to greater than 15% of full reactor power. I The IRMs provide control rod block and scram functions at 108 and 120, respectively, of a l 125 division scale.

The APRMs do not have incore detectors of their own but receive input from the LPRM detectors which are located at various levels throughout the core. The APRMs monitor '

core power from about 1% of full reactor power to 125% of full reactor power. The APRMs represent a core average power level while the IRMs and SRMs indicate a local power level. In OPCON 5 the APRMs operate in the setdown mode to provide a control rod block and scram function at 12% and 15% core average power, respectively.

The safety design bases of the IRM subsystem is to generate trip signals to prevent fuel damage resulting from anticipated or abnormal operational transients that could possibly

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occur while operating in the intermediate power range. The safety design bases of the ,

APRM subsystem is to generate trip signals in response to average neutron flux increases in time to prevent fuel damage while the plant is in the operating power range. The independence and redundancy incorporated in the design of the IRM and APRM subsystems are consistent with the safety design bases of the NMS and RPS. Following the requested change these design bases for the APRMs and IRMs will continue to be met.

Reactivity Control During Refueling Operations  !

There are various levels of control to prevent inadvertent reactor criticality and fuel damage during refueling operations. Each of these systems and mechanisms contribute to defense-in-depth design and operation.

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1) Licensed plant operators are trained to operate equipment and follow approved procedures.

! 2) Plant approved refueling and maintenance procedures specify core alteration steps.

3) SRMs indicate the potential for reactor criticality and generate a control rod block signal on high neutron flux levels. In addition, when shutdown margin has not been demonstrated. TS Section 3.9.2 requires the shorting links be removed so that the SRMs will operate in the noncoincident scram mode to caust a reactor scram as necessary, a

4) Refueling Interlocks (RIs) prevent the removal of more than one control rod and prevent the insertion of fuel bundles into the core unless all control rods are fully inserted. ,

5) The IRMs and APRMs provide an indication of local power and average power, respectively. IRMs and APRMs will provide rod blocks and scram signals on high neutron flux levels. ,

The IRMs will continue to be required by TS to be operationalin OPCON 5 any time a control rod is withdrawn from a fueled cell. The IRMs are designed to indicate and respond

t Attachment 2 to GNRO-93/00049  ;

Page 5 of 11 to neutron flux increases at local core locations. The APRMs are designed to monitor and respond (scram and/or control rod block) to a core average neutron flux level. The most likely reactivity insertion transient expected during refueling would be a core alteration type event, e.g., control rod withdrawal or fuel assembly insertion into the core (The R!s prevent the insertion of a fuel assembly any time a control rod is withdrawn; therefore, the RPS trip  !

function and the control rod block functions of the IRMs and APRMs would have no affect on this event.). A core alteration event would result in a local core criticality transient more readily detected by the IRMs and/or SRMs than by the APRMs.

The lRMs and SRMs are designed and calibrated to respond to a neutron flux level that is significantly less than the flux level monitored by the APRMs. For example, during refueling, when the IRMs are on their most sensitive range, the IRMs will generate a scram signal at less than 0.01% core average power while the APRMs will generate a scram signal at 15% core average power. The IRMs and the SRMs will continue to act as a

' backup protection system to the R!s during refueling operations.

Ris are required to be operational during refueling operations in OPCON 5. The purpose of the Ris is to restrict the movement of the control rods and the operation of the refueling equipment to reinforce operational procedures that prevent the reactor from becoming critical during refueling operations. Ris require that all control rods be fully inserted into the core prior to allowing reactor operators to select and withdraw a single control rod. Other .

Ris will prevent the withdrawal of a control rod if the fuel loaded refueling platform is over

, the core. Also, the Ris require an all-rods-in signal before allowing a fuel loaded refueling platform to go over the core.

TS and plant operating procedures allow only one control rod to be withdrawn at a time while the plant is in OPCON 5 and the mode switch is in

• Refuel.* The core loading pattern i

is designed to ensure that the core is subcritical by a specified margin under these

< conditions. Additional control rods can be removed from the core only if the core cell is

defueled.

The design of the control rod drive system reduces the probability of a control rod error during refueling. For example, the latching action of the collet finger assembly serves to '

j lock the index tube in place. The velocity limiter physically prevents the control blade from being removed from the core with fuel in place. >

Updated Final Safety Analysis Report 4

The GGNS Updated Final Safety Analysis Report (UFSAR) Secti on 15.4.1.1, " Rod

Withdrawal Error - Low Power," evaluated the potential for a control rod removal error during refueling. The concern is potential inadvertent criticality during shutdown conditions due to the following events.

1. Removal of the highest worth control rod.

2. Withdrawal of a second control rod.

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3. Control Rod removal from a fueled cell.

The UFSAR concludes that the above scenarios are adequately precluded by refueling interlocks, core design, and control rod hardware design. However, should operator errors, followed by equipment malfunctions, result in an inadvertent criticality event, necessary safety actions (control rod block or scram) will be taken prior to violation of a safety limit.

i Attachment 2 to GNRO-93/00049 '

Page 6 of 11 Following the proposed TS change the IRMs and SRMs will remain available to provide a rod block or scram function as appropriate.

Summary in summary, the IRMs and APRMs operability requirements being removed from the TS are not necessary for safe operation of the plant for the following reasons:

1. During OPCONs 3 and 4 (except for a single control rod removed as allowed by TS 3.9.10.1) all control rods are required to be inserted and, therefore, the operability ;

or inoperability of the RPS trip functions and control rod block functions of the IRMs and APRMs could have no affect on core reactivity.

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2. The IRMs will continue to be required by TS to be operable in OPCON 5 when any

, control rod is withdrawn from a fueled cell. The IRMs will generate an RPS scram or control rod block if neutron flux increased to the applicable setpoint.

3. The IRMs and SRMs are designed and calibrated to be more sensitive to neutron flux than the APRMS. '

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4. The IRMs and SRMs are designed to monitor local core events while the APRMs provide a measure of core average power condition. The IRMs and SRMs can I monitor and react to the most probable reactivity events expected during refueling, i.e., control rod withdrawal.

5. The IRMs and SRMs would detect and respond (control rod block or reactor scram, as applicable) to an inadvertent criticality event before the APRMs would provide a ,

trip function.  !

6. The withdrawal of only one control rod in OPCON 5 is permitted by the One-rod-out interlock while in " Refuel." The core is designed to be subcritical with any one rod ,

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7. The withdrawal of a second control rod or inadvertent addition of a fuel bundle in OPCON 5 is precluded by Ris, refueling procedures, and administrative controls.  !

8. The APRMs will still be required to be operational during a shutdown margin ,

demonstration performed in OPCON 5 (a special test exception in the TS).

9. The SRMs are required to be operational in OPCON 5 and will provide control rod blocks when required and a scram when the shorting links are removed as ;equired by the TS.

10. The transient analysis discussed in the UFSAR does not require the IRMs or APRMs to be operational in OPCONs 3,4, or 5 to mitigate an undesirable operational or transient condition except during shutdown margin demonstrations.

In conclusion, monitoring of neutron flux levels, administrative controls, plant procedures, and refueling interlocks provide and maintain the defense-in-depth design and operation j

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which precludes the need for the IRMs or APRMs to be operable when the unit is shutdown with all rods inserted. The proposed changes willinsure that the IRMs remain a backup level of protection when any control rod is withdrawn from a fueled cell and that the SRMs - ,

, 1 Attachment 2 to GNRO-93/00049 Page 7 of 11 and APRMs will be available dunng shutdown margin demonstrations.

The relocation of the requirements for these instruments associated Control Rod Block System involses no substantive changes (other than changes in the OPERABILITY requ;rements consistent with the changes requested for the RPS functions of the instrementation) to the surveillance and operability requirements currently contained in the GGNS TS. Deletion of the TS requirements is complemented by the incorporation of that information into plant procedures. This information will be adequately controlled via the administrative requirements specified in TS 6 8 ad TS 6.5.3. Those requirements include  !

review of changes for unreviewed safety ques: ^ is in accordance with the provisions of  ;

10CFR50.59. Such changes are reported to the NRC in the annual report submitted pursuant to 10CFR50.59. GGNS adheres to a policy of verbatim compliance with all plant procedures. These changas, therefore, constitute an administrative revision only. ,

The TS pages affected by this proposec; amendment are included as Attachment 3 and are  ;

marked up to reflect the proposed changes.

C. NO SIGNIFICANT HAZARDS CONSIDERATIONS  :

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, 1. Entergy Operations, Inc. ;.1 proposing that the GGNS TS be amended to remove the i operability requirements when the unit is shutdown for the Intermediate Range j Monitor (IRMs) except when any control rod is withdrawn from a fueled cell and  ;

from the Average Power Range Monitors (APRMs) except during shutdown margin  :

demonstrations. .

2. The Commission has provided standards for determining whether a no significant hazards consideration exists as stated in 10CFR50.92(c). A propoced amendment to an operating license involves no significant hazards if operation of the faci!ity in accordance with the proposed amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of i safety.

3. Grand Gulf Nuclear Station (GGNS) has evaluated the no significant hazards ,

considerations in its request for a license amendment. In accordance with  ;

10CFR50.91(a), GGNS is providing the following analysis of the proposed i amendment against the three standards in 10CFR50.92:

a. No significant increase in the probability or consequences of an accident previously evaluated results from this change.

Not requiring intermediate Range Monitor (IRMs) or Average Power Range Monitors (APRMs) to be operational when the unit is shutdown and all control rods are inserted will not increase the probability of inadvertent reactor criticality during refueling operations. The Refueling interlocks (Ris) and procedural restrictions provide assurance that inadvertent criticality does not occur due to the simultaneous withdrawal or removal of two control rods or due to the inadvertent insertion of a fuel bundle into a core locstion with a control blade removed. In addition, the Source Range Monitors (SRMs) wd! cor tinue to be available to monitor neutron flux and provide appropriate action during Operational Condition (OPCON) 5.

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Attachment 2 to GNRO-93/00049  :

Page 8 of 11  !

The Updated Final Safety Analysis Report (UFSAR) Section 15.4.1 discusses the potential for a control rod withdrawal error during refueling and start-up operations. The discussion concludes that the withdrawal of one control rod does not require a safety action because the total worth of one control }

rod is not sufficient to cause criticality. The attempted withdrawal of two control rods would result in a control rod block initiated by the RIs. The i SRMs and IRMs which will continue to be required by Technical  !

Specifications (TS) to be operable while in OPCON 5 and any control rod is i removed from a fueled cell, are designed to generate a rod block or reactor ,

scram on high neutron flux and will, therefore, continue to provide backup  :

protection for the Ris during refueling.

During OPCON 5, the IRMs, when any control rod is removed from a fueled f cell, and the SRMs will continue to be required by TS to be operable to support the safety design bases of the Reactor Protection System (RPS) and i the control rod block system. The SRMs provide the plant operator with  !

neutron flux levels from startup conditions to the IRM operating range. The SRMs and IRMs are designed to respond to local core conditions and would indicate and respond (control rod block or scram) to an accident condition to 4 mitigate the transient. Thus, the APRMs are not necessary to be operable when the plant is shutdown. The proposed TS change will not alter the current requirements that the APRMs he operable during shutdown margin demonstrations.

The consequences of an accident will not be increased by the proposed TS r 4 change because of the existing lines of defense assumed in the UFSAR to ,

prevent and mitigate an inadvertent enticality event during refueling, e.g., E i administrative restrictions, refueling procedures, licensed plant operators, and Ris. Furthermore, the SRMs and IRMs will continue to provided an i additionallayer of protection and should the number of operable IRM or SRM i channels be less than that required by TS, the TS require that core afteration activities be suspended and allinsertable control rods be inserted into the core, i The changes requested by this submittal are consistent with NUREG-1434, Revision 0, ' improved Standard Technical Specifications." (Reference 11 although editorial changes have been made in the presentation of the ,

! requirements to maintain consistency with the current GGNS TS. This  ;

requested change also relocates the operability requirements for the APRMs '

and the IRMs associateo with the Control Rod Block System to be controlled ,

4 by plant procedures consistent with NUREG-1434. ,

The relocation of the requirements for these instruments associated Control 7 Rcd Block System involves no substantive changes (other than changes in >

the OPERABILITY requirements consistent with the changes requested for ,

the RPS functions of the instrumentation) to the surveillance and operabi'ity l requirements currently contained in the GGNS TS. Deletion of the TS requirements is complemented by the incorporation of that information into f plant procedures. This information will be adequately controlled via the '

administrative requirements specified in TS 6.8 and TS 6.5.3. Those requirements include review of changes for unreviewed safety questions in accordance with the provisions of 10CFR50.59. Such changes are reported ,

to the NRC in the annual report submitted pursuant to 10CFR50.59. GGNS

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Attachment 2 to GNRO-93/00049 j Page 9 of 11  ;

t adheres to a policy of verbatim compliance with all plant procedures. These l changes, therefore, constitute an administrative revision only.

The changes requested for the RPS function of the IRMs are consistent with the requirements contained in NUREG-1434 in only requiring the IRMs to be operable when the unit is shutdown if a control fod is withdrawn from a fueled cellin OPCON 5. The changes requested for the APRMs are consistent with NUREG-1434 in removing the operability requirements for i the APRMs as part of the RPS in OPCON 3 and restricting the operability requirements for the APRMs as part of the RPS during OPCON 5.

The requested change to the APRM operability requirements differs from the requirements identified in NUREG-1434 Revision 0 in that NUREG-1434 identifies that the neutron flux and inoperative trips of the APRMs should be operable in OPCON 5 any time that a control rod is withdrawn. The requested change would only require that these APRM trip functions be operable during the shutdown margin demonstrations allowed by TS 3.10.3.

This modification in APRM operability requirements has been previously requested by another utility and granted by the NRC (Reference 2). The Owners Group Technical Specification Improvement Committee proposed a line item improvement to NUREG-1434 consistent with the requested APRM operability requirements in the Industry /NRC meeting in Dallas on 2/19/93.

This improvement was accepted by the NRC in the industry /NRC meeting in New Orleans on 3/18/93.

Therefore, there is no increase in the probability or consequences of a previously evaluated accident due to the proposed changes.

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b. This change would not create the possibility of a new or different kind of accident from any previously analyzed.

The proposed changes to the TS will remove the IRM and APRM cperability requirements while the unit is shutdown (except in OPCON 5 when any I control rod is wit., drawn from a fueled cell for the IRMs and during shutdown margin demonstration testing for the APRMs); however, the SRMs and IRMs will still be required to b6 operable whenever the unit is shutdown and their RPS trip functions or control rod block functions could affect core reactivity.

The IRMs and SRMs are designed to detect and respond to increases in ,

neutron flux within the local core regions. Any inadvertent increases in neutron flux during refueling would originate at a local core location, i.e., rod ,

withdrawal error or fuel bundle insertion. TS will continue to require IRM  !

and SRM operability and these systems will continue to generate a scram signal or control rod block if neutron flux increased to the setpoint when the scram signal or control rod block would affect core reactivity.

No new types of accidents would be introduced since the SRMs and IRMs are available and required to be operable when their RPS trip functions or control rod block functions could affect core reactivity. Both SRMs and  !

'PMs would indicate and provide a control rod block or scram signal, as ,

appropriate, to an increase in neutron flux to mitigate a transient event. ,

Furthermore, shou!d the number of operable IRM or SRM channels be less

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than that required by TS, the TS require that core alteration activities be  !

suspended and all insertable control rods be inserted into the core.  !

The proposed changes do not introduce any new modes of plant operation, make any physical changes, or alter any operational setpoints. When the l unit is shutdown, removing the IRM operability requirement except when a i control rod is withdrawn from a fueled cell and APRM operability except  ;

during shutdown margin demonstrations will not affect the response of j safety-related equipment as previously evaluated in the UFSAR.

2 4 The relocation of the requirements for these instruments associated Control  ;

Rod Block instrumentati on involve no substantive changes (other than changes in the OPERABILITY requirements consistent with the changes requested for the RPS functions of the instrumentation) to the surveillance and operability requirements currently contained in the GGNS TS. Deletion -

of the TS requirements is complemented by the incorporation of that f information into plant procedures. This information will be adequately i controlled via the administrative requirements specified in TS 6.8 and TS 6.5.3. Those requirements include review of changes for unreviewed safety  ;

questions in accordance with the provisions of 10CFR50.59. Such changes  !

are reported to the NRC in the annual report submitted pursuant to 10CFR50.59. GGNS adheres to a policy of verbatim compliance with all  ;

plant procedures. These changes, therefore, constitute an administrative

revision only.

i a t Therefore, the possibility of a new or different kind of accident from any j previously evaluated is not created. l

c. This change would not involve a significant reduction in the margin of I safety. ,

The Bases for TS 3/4.3.1, " Reactor Protection System Instrumentation" l identifies that one of the functions of the RPS is to prevent inadvertent  ;

l criticality. When the unit is shutdown, the revised specification will still i ensure that the RPS will be able to prevent an inadvertent criticality event.

The specification provides this assurance by requiring SRM operability during '

4 OPCON 5, IRM operability during OPCON 5 any time a control rod is withdrawn from a fueled cell, and APRM operability during shutdown margin j demonstrations. This willinsure that a scram signalis generated if neutron flux increased to the applicable setpoint when the scram signal would affect core reactivity.  ;

l l The Bases for TS 3/4.3.6, Control Rod Block Instrumentation identifies that i the operability of the control rod block instrumentation in OPCON 5 is to provide diversity to the one-rod-out interlock. During refueling operations, ,

the operability requirements for the SRMs and the relocated requirements for the IRMs when a control rod is withdrawn from a fueled cell, and the  !

APRMs during shutdown margin demonstrations will still ensure that this diversity is maintained.

t The proposed TS changes do not involve a significant reduction in a margin  !

of safety. The proposed changes do not alter the manner in which safety limits. limiting safety system settings, or limiting conditions for operation are L

.i t

Attachment 2 to GNRO-93/00049 Page 11 of 11 determined.

4. Based on the above evaluation, Entergy Operations, Inc. has concluded that  ;

operation in accordance with the proposed amendment involves no significant [

• f hazards considerations.

D. REFERENCES j I

1) NUREG-1434, Revision 0 of the improved Standard Technical Specifications.

2) Letter Richard J. Clark (NRC) to George A. Hunger (Philadelphia Electric Company),  ;

APRM Operability during OPCON 5 (TSCR NO. 90-02-0) Limerick Generating Station, Units 1 and 2 (TAC NOS. 76958/76959), dated July 30,1990. l f-t i

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