2CAN089802, Application for Amend to License NPF-6,revising TS 3.1.3.2 Action Requirements for CEA Position Indicator Channels

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Application for Amend to License NPF-6,revising TS 3.1.3.2 Action Requirements for CEA Position Indicator Channels
ML20236Y513
Person / Time
Site: Arkansas Nuclear Entergy icon.png
Issue date: 08/06/1998
From: Hutchinson C
ENTERGY OPERATIONS, INC.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20236Y515 List:
References
RTR-NUREG-1432 2CAN089802, 2CAN89802, GL-91-08, GL-91-8, NUDOCS 9808120272
Download: ML20236Y513 (10)
v • d • e


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, e Enttrgy operation 2,Inc.

-En.tergy =u Te'501858 4888 C. Randy Hutchinson Vr2 PresdM Ope'ato+ AND August 6,1998 2CAN089802 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station OPI-17 Washington, DC 20555

Subject:

Arkansas Nuclear One - Unit 2 Docket 'No. 50-368 Licerse No. NPF-6 Technical SpeciScation Change Request Concerning CEA Position Indication and the Relocation of the Containment Penetration Overcurrent Device Table Gentlemen:

Attached for your review and approval is a proposed technical specification change that revises the Action requirements for the Arkansas Nuclear One - Unit 2 (ANO-2) Control Element Assembly (CEA) position indicator channels. The Action requirements listed in Specification 3.1.3.2 are being modified consistent with the requirements of NUREG-1432, >

" Standard Technical Specifications for Combustion Engineering Plants."

This change also includes the relocation of Technical Specification Table 3.8-1, " Containment Penetration Conductor Overcurrent Protective Devices." On May 6,1991, the NRC issued Generic Letter (GL) 91-08, " Removal of Component Lists From Technical Specifications" providing guidance for the removal of this component list. This GL allows the relocation of this list into plant procedures as long as they are subject to the change control provisions in the Administrative Controls Section of the technical specifications.

All of the containment penetration conductor overcurrent protective devices listed in Table 3.8-1 have been verified to be listed in ANO-2 plant procedures. These procedures are subject to the change control provisions listed in the Administrative Controls Section of the ANO-2 Technical Specifications.

The proposed change has been evaluated in accordance with 10 CFR 50.91(a)(1) using criteria in 10 CFR 50.92(c) and it has been determined that this change involves no signi6 cant hazards considerations. The bases for these determinations are included in the attached submittal.

Entergy Operations requests that the effective date for this change be within 30 days of issuance. Although this request is neither exigent nor emergency, your prompt review is ,

requested. -

s4;, U. . g 9808120272 980806 ..

PDR ADOCK 05000368 '

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U. S. NRC August 6,1998 2CAN089802 Page 2 Very tmly y s,

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l l C /r c Attachments To the best of my knowledge and belief, the statements contained in this submittal are true.

SUBSCRIBED AND SWORN TO before me, a Nota ublic in and for Mo County and the State of Arkansas, this _6" day of u n.Eb ,199-8. /

a __ ___________

~

f ~ ~"OFFIClAE SFAlf I l Andrea Pierce '

m j L Notary Public, State of Arkarua County of Pope Notary Pubh,c My Commluion Ex"p.12/15/2007" " ' ,

My Commission Expires /.1//S/eRoo7 3 C="

cc: Mr. Ellis W. Merschoff Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 i NRC Senior Resident Inspector Arkansas Nuclear One P.O. Box 310 l London, AR72847 Mr. William D. Reckley NRR Project Manager Region IV/ANO-1 & 2 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-H-3  ;

One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. David D. Snellings Director, Division of Radiation Control and Emergency Management Arkansas Department of Health 4815 West Markham Street l Little Rock, AR 72205 l-

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ATTACHMENT ID f i

2CAN089802 PROPOSED TECHNICAL SPECIFICATION wu '

RESPECTIVE SAFETY ANALYSES IN THE MATTER OF AMENDING LICENSE NO. NPF-6 ENTERGY OPERATIONS. INC.

ARKANSAS NUCLEAR ONE. UNIT TWO DOCKET NO. 50-368 l

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. Attachment to 2CAN089802 Page1of7 DESCRIPTION OF PROPOSED CHANGES The Action requirements for Technical Specification (TS) 3.1.3.2 were modified as follows:

  • The requirement that allowed a maximum of one Control Element Assembly (CEA) per group with less than two position indicator channels was removed.
  • Action "a" was modified by the addition of the words "at least one of" and the word

" channel" was modi 6ed to " channels".

. Action "c" was modified by the removal of the associated CEA group requirements and to allow the use of the " Full In" limit. TS 3.1.3.5 was also added to Action "c" as a reference to be used when positioning CEAs along with the existing references to 3.1.3.1 and 3.1.3.6.

TS 3.8.2.5 has been modified by the removal of all references to Table 3.8-1 and the addition of

- the other changes required by Generic Letter 91-08 which includes the relocation of Table 3.8-1.

BACKGROUND FOR THE CEA POSITION INDICATION CHANGES The axial position of shutdown and regulating CEAs is indicated by two separate and independent

systems, which are the plant computer CEA pulse counting position indication system and the reed switch position transmitter (RSPT) indication system. The pulse counting position indication system counts the commands sent to the CEA gripper coils from the control elenwnt drive mechanism control system (CEDMCS) that moves the CEAs. There is one step counter for each group of CEAs. Individual CEAs in a group all receive the same signal to move and should, therefore, all be at the same position indicated by the group step counter for that group. The pulse counting position indication system is considered highly precise because one step equals

% inch of CEA movement. If a CEA does not move one step for each command signal, the step counter will still count the command and incorrectly reflect the position of the CEA.

The RSPT indication system provides a highly accurate indication of actual CEA position, but at a L lower precision than the step counters. The two reed switch stacks (RSPT #1 and RSPT #2) are mounted outside the reactor coolant system (RCS) pressure boundary, along the upper pressure housing. The individual reed switches are actuated by the permanent magnet attached to the top i l of the CEA extension shaft. No mechanical or electrical connections exist between the permanent i j magnet and the reed switches, only magnetic lines of flux that penetrate the RCS pressure boundary to actuate the switches.' This system is based on inductive analog signals from a series of reed switches spaced along a tube with a center to center distance of 1.5 inches, which equates to two steps.

In addition to RSPT #1 and RSPT #2, a pair of reed switches are positioned for the lower electrical limit (LEL) and se upper electrical limit (UEL) for each CEA. These reed switches are positioned at the fully inserted and the fidly withdrawn positions. The LELs and the UELs are referred to by TS 3.1.3.2 and its Bases as the " Full In" and " Full Out" limits respectively. These lindts provide a position indication system to the operator in the form of a light at the CEA control panel when the CEA is at the respective positions. The TS allow the use of the LELs and

r 1 Attachment to I

-3CAN089802  !

Page 2 of 7 I UELs as an independent means of determining CEA position. However, they are allowed if only two of the required CEA position indication for an individual CEA are inoperable and the associated CEA is positioned to the associated electrical limit.

TS 3.1.3.2 requires the operability of at least two of the three CEA position indicator channels to determine CEA positior,s and thereby ensure compliance with the CEA alignment and insertion limits. The three CEA position indication systema listed in TS 3.1.3.2 are RSPT #1, RS.PT #2, and the pulse counter. However, Action "c" to this specification allows continued operation with  !

only one of the three indication systems operable for a maximum of one CEA per group if the  !

CEA group is maintained fully withdrawn at its " Full Out" limit.

1 The Bases for TS 3.1.3.2 explain that the CEA " Full In" and " Full Out" limits provide an additional indapaadaat means for determining the CEA positions when the CEAs are at either their fully inserted or fully withdrawn positions. The Bases go on to state that the action-statements applicable to inoperable CEA position indicators permit continued operation when the positions of CEAs with inoperable position indicators can be verified by the " Full In" or " Full Out" limits. Although the intent of the TS 3.1.3.2 may have originally been to allow continued operation using the " Full In" limits, it has never been clearly addressed by Action "c" from its initialissuance )

ANO-2 has previously had a group of CEAs that contained two separate CEAs with an RSPT inoperable. This was in compliance with TS 3.1.3.2 without reliance on its associated actions.

The plant computer pulse counter was one of the two remaining onerable position indication systems for each of the two CEAs. If the plant computer had fa7 dng this period of time, entry into 3.0.3 would have been required because TS 3.1.3.2 allowe y one CEA cer aroup with only one indication to be operable.

During normal 100% power operation, the CEAs are fully withdrawn at the programmed insertion limit. Me progrunmed insertion limit was developed due to the concern with CEA j guide tube / fire. tip wear Doncerns The programmed insertion limit is discussed in letter dated June 16,1978, from Robert E. Martin of the NRC to Arkansas Power and Light Company (2CNA%7815). The programmed insertion limit starts the operating cycle with all the CEAs 3 l

fully withdrawn or at the UEL. At approximately every 90 effective full power days (EFPD) )

l through out the cycle the CEAs are inserted an additional step (one step equals % inch) until they are 3 steps inserted. At approximately every 90 EFPD interval thereafter, the CEAs are withdrawn a step. This process is continued until the CEAs are again at their UEL. The process

!' is then repeated until the particular operating cycle is over. This periodic movement of the CEAs l allows the CEA finger tips to be inserted inside the CEA guide tube varying amounts and thus spreading the wear pattern over a larger surface a ca.

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4 l Attachment to 2CAN089802 l

'Page 3 of 7 BACKGROUND FO'R THE TABLE 3.8-1 CHANGES ,

Generic Letter (GL) 91-08, " Removal of Component Lista From Technical Specifications," was issued as a line item improvement to the TS. The GL encouraged licensees to propose TS changes consistent with its guidance. Enclosure One of the GL provides guidance on the changes j j neces sary for the removal of specific lists of components from the TS. Table 3.8-1 is one of the  !

l specific lists of components contained in the GL. The GL provides guidance for preparing a I l request for a license amendment to remove component lists from TS. This provides an NRC acceptable alternative to identifying every component by its plant identification number within the TS. )

1 The GL allows the relocation of this !ist into plant procedures as long as they are subject to the change control provisions in the Administrative Controls Section of the Technical Specifications.

All of the containment penetration conductor overcurrent protective devices listed in Table 3.8-1

! have been verified to be listed in ANC-2 plant procedures. These procedures are subject to the

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change control provisions listed in the administrative Controls Section of the ANO-2 Technical Specificatiota.

DISCU$SION OF CHANGE f The . Action requirements for Technical Specification (TS) 3.1.3.2 were modified to be consistent l with the requirements of Revision 1 of NUREG-1432, " Standard Technical Specifications for Combustion Engineering Plants" or othetwise known as Improved Technical Specifications (ITS).

The requirement that restricted each CEA group to a maximum of one CEA with less thr.n two )

position indicator channels was removed. The ITS does not place any restrictions on the number

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of CEAs in a single group that can use Action "c." The ITS will permit any number of CEAs in an individual group with only one CEA position indication operable, as long as the associated CEAs are at the " Full In" or " Full Out" limit. -;

~ Additionally, the ITS does not require the piecement of the other CEAs in the associated group at the " Full Out" limit when one of the CEAs in the group has only one of the required position indication systems opersble. All of the remaining CEAs in the associated group have at least two j independent means of CEA position indication operable or they also would be required to be l positioned to their " Full Out" limit, Action "c" also requires the individual CEA and its group to l be properly aligned in accordance with Specifications 3.1.3.1 and 3.1.3.6. These requirements eliminate the need for pulling the remaining CEAs in the group to the " Full Out" limit because it  ;

will ensure the alignment requirements are maintained.

The " Full Out" limit that is discussed in the TS is provided for each individual CEA. It provides another position indication when the CEA is fully withdrawn at the UEL. If the entire group is to be veithdrawn from the programmed insertion limit to the " Full Out" limit as currently required by TS 3.1.3.2, each CEA will have to be withdrawn separately and not as a group. Group motion is

< ' Attachment to 2CAN089802 '

Page 4 of 7 inhibited while in the programmed insertion band and thus requires each CEA to be selected individually and withdrawn.

By eliminating the requirement to place the group at the " Full Out" limit, the operator will have more time to focus on the individual CEA position indication prob 1.em at hand, rather than moving the remaining CEAs in the group unnecessarily. Anytime that a CEA is moved, a small probability exists for it to slip or drop into the core. If this were to occur while attempting to align the group to the " Full Out" limit, a plant transient would be initiated. Additionally, anytime <

the CEAs are operated, there exists a small probability of an error. Thus, the CEA group withdrawal requirements currently listed in TS 3.1.3.2 could unnecessarily increase the probability of CEA misoperation.

Action "a" was modified by the addition of the words "at least one of' and modified the word channel to channels. This change is considered editorial in nature. When this action is entered, two of the position indicators are inoperable, either one of the position indicators restored to operable status is acceptable.

Action "c" was modified by the removal of the ast,ociated CEA group requirements and to allow i the use of the " Full In" limit. The associated CEA group position will continue to be verified every 12 honrs as required by specifications 4.1.3.2, 4.1.3.5 and 4.1.3.6. The Bases foi TS 3.1.3.2 clearly indicate that the CEA " Full In" and " Full Out" umits provide an additional independent means for determining the CEA positions when the CEAs are at either their fully inserted or fully withdrawn positions. The Bases also state that the action statements applicable to inoperable CEA position indicators permit continued operations when the positions of CEAs with inoperable position indicators can be verified by the " Full In" or " Full Out" limits. Although '

the intent of the TS 3.1.3.2 may have originally been to allow continued operation using the " Full In" limits, it has never been clearly addressed by Action "c" from its initial issuance. The ITS allows the use of either the " Full In" or " Full Out" limits.

TS 3.1.3.5 was added to Action "c" to ensure compliance with the requirements of this specification along with the requirements of 3.1.3.1 and 3.1.3.6. This will prevent the use of the

" Full In" limits for the shutdown CEAs when in the mode of applicability of TS 3.1.3.5.

Specification 3.1.3.5 requires all shutdown CEAs to be fully withdrawn and therefore, prohibits the use of the " Full In" limits for the shutdown CEAs.

TS 3.8.2.5 has been modified by the removal of all references to Table 3.8-1 and the addition of the other changes required by Generic Letter 91-08 for the relocation of Table 3.8-1. Table 3.8-1 which includes pages 3/4 8-13 through 3/4 8-32, were removed from the TS. All the pages that were left blank after the relocation of this list have been removed from the TS by this change.

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' Attachment to 2CAN089802 Page 5 of'i DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION An evaluation of the proposed change has been performed in accordance with l' 10 CFR 50.91(a)(1) regarding no - significant hazards considerations using the standards in 10 CFR 50.92(c). A discussion of these standards as they relate to this amendment request follows:

Criterion 1 - Does Not Involve a Significant Increase in the Probability or Consequences of i an Accident Previously Evaluated. I l

1 This technical. specification (TS) change request contains the relocation of Table 3.8-1, Containment Penetration Conductor Overcurrent Protective Devices, and changes to the control element assembly (CEA) position indication.

Generic Letter (GL) 91-08, " Removal of Component Lists From Technical Specifications," was issued as a TS line item improvement by the NRC. Table 3.8-1 is one of the specific lists of components contained in the GL. TS Table 3.8-1 and all its references have been removed from j Specification 3/4.8.2.5 in accordance with the GL. This change is considered administrative in nature because the requirements for operability, the limiting conditions for operation, the surveillance requirements and their frequencies for the containment penetration conductor overcurrent protective devices remains the same. This amendment request fundamentally modifies the physical location of the devices listed in Table 3.8-1 from the TS to the plant procedures. These changes have no affect on the probability or consequences of any accident previously evaluated.

The remaining changes included in this amendment request are those relating to the CEA position indication. The Action requirements for TS 3.1.3.2 were modified to be consistent with the requirements of NUREG-1432, " Standard Technical Specifications for Combustion Engineering Plants." The most recent revision of NUREG-1432 was used to produce this change because it represents the latest guidance for the TS CEA position indication requirements that are applicable to ANO-2 and acceptable to the NRC.

The requirement was removed from TS 3.1.3.2 that restricted each CEA group to a maximum of one CEA with less than two of the required position indicator channels. NUREG-1432 places no i

requirements on the number of CEAs in a group with less than two of the required position indicator channels. NUREG-1432 would allow all the CEAs in a group to have only one of the required CEA position indications operable. In this situation, the associated CEAs with less than two of the required position indicator channels would have to be placed at their " Full In" or " Full Out" limits.

TS 3.1.3.2 was modified to allow the use of the " Full In" or " Full Out" limits which ensures this specification is consistent with its bases and NUREG-1432. The TS will still maintain the requirements for two independent means of determining CEA position with this amendment request. With two independent means of determining CEA position, reliable determination of l l

actual CEA position will be maintained.

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' Attachment to 2CAN089802 Page 6 of 7 Additionally, NUREG-1432 does not require the placement of any other CEAs in the associated group at the " Full Out" limit when one of the CEAs in the group has only one of the required position indication systems operable. All of the remaining CEAs in the associated group still have at least two independent means of CEA position indication or they would already be required to be positioned to the " Full Out" limit to restore the second position indication. The TS retains the requirements for the individual and group CEA alignment in accordance with Specifications 3.1.3.1 and 3.1.3.6. These requirements also eliminate the need for pulling the remaining CEAs in the group to the " Full Out" limit as long as the alignment requirements are maintained.

These changes will allow the operator more time to focus on the individual CEA position indication problem rather than moving the remainder of the CEAs in the group unnecessarily.

Anytime that a CE.8 % moved, a small probability exists for it to slip or drop into the core. If this were to occur while attempting to align the group to the " Full Out limit, a reactor transient would be initiated. Additionally, anytime the CEAs are operated, a small probability of an error exists. Removing the unnecessary requirement for the group withdrawal could decrease the probability of CEA misoperation. CEA position indication is not considered as an accident initiator. Retaining the requirements to maintain at least two independent means of determining CEA position will ensure the consequences of all the accidents previously evaluated remain j unchanged.

I Therefore, this change does net involve a significant increase in the probability or consequences of any accident previously evaluated.

Criterion 2 - Does Not Create the Possibility of a New or Different Kind of Accident from any Previously Evaluated.

The portions of this _ change that are made in accordance with GL 91-08 are considered administrative in nature and do not result in the creation of a new or different kind of accident from any previously evaluated.

The bases for TS 3.1.3.2 state that the action statements applicable to inoperable CEA position indicators permit continued operation when the positions of CEAs with inoperable position indicators can be veri 6ed by the " Full In" or " Full Out" limits. Although TS 3.1.3.2 may have  ;

originally been intended to allow continued operation using the " Full In" limits, it has never been clearly addressed in the specification. NUREG-1432 allows the use of both the " Full In" or " Full Out" limits. This amendment request will not change the methods for CEA operation, although it l

will reduce unnecessary CEA manipulations due to CEA position indication problems.

The requirements of Specification 3.1.3.1 will ensure that an individual CEA is maintained in proper alignment with the remaining CEAs in the group. Specification 3.1.3.6 will ensure the CEA groups are maintained within the proper withdrawal sequence and insertion limits.

Speci6 cation 3.1.3.5 will ensure the shutdown CEA groups are maintained in the " Full Out" position. The CEA position indication changes allowed by this amendment request, including the I

  • Attachment to 2CAN089802 Page 7 of 7 allowance to use the " Full In" limits, can produce a CEA configuration that is different from that allowed by the current TSs. However, the allowed configurations will be bounded by the TS 3.1.3.2 Action "c" requirements for compliance with Specifications 3.1.3.1, 3.1.3.5, and 3.1.3.6.

Therefore, the action requirements of TS 3.1.3.2 will ensure the CEAs are operated consistent with the safety analysis assumptions.

Therefore, this change does RQt create the possibility of a new or different kind of accident from any previously evaluated. j Criterion 3 - Does Not Involve a Significant Reduction in the Margin of Safety.  !

The ponions of this change that are made in accordance with GL 91-08 are considered administrative in nature and have no effect on the margin of safety. The remaining changes can result in a lower probability of CEA misoperation and reduce the potential of plant transients due ta CEAs that slip or drop into the core while performing unnecessary group realignments. These changes can also reduce unnecessary plant shutdowns, due to unneeded restrictions on CEA position indication. An unnecessary plant shutdown produces an opportunity for plant upsets that can be avoided by this change. The proposed TS provide an equivalent level of safety as those specifications that currently exist. Therefore, this change does nat involve a significant reduction in the margin of safety.

Therefore, based upon the reasoning presented above and the previous discussion of the amendment request, Entergy Operations has determined that the requested change does act involve a significant hazards consideration.

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