TSTF-15-13, TSTF Comments on Draft Model Safety Evaluation of Traveler TSTF-547, Revision 0, Clarification of Rod Position Requirements, and Transmittal of TSTF-547, Revision 1

TSTF Comments on Draft Model Safety Evaluation of Traveler TSTF-547, Revision 0, Clarification of Rod Position Requirements, and Transmittal of TSTF-547, Revision 1

ML15365A610
Person / Time
Site:	Technical Specifications Task Force
Issue date:	12/31/2015
From:	Clark J, Gustafson O, Hegrat H, Morris J B&W Pantex, BWR Owners Group, Combustion Engineering, PWR Owners Group, Technical Specifications Task Force, Westinghouse
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TSTF-15-13
Download: ML15365A610 (98)

Text

TECHNICAL SPECIFICATIONS TASK FORCE TSTF A JOINT OWNERS GROUP ACTIVITY December 31, 2015 TSTF-15-13 PROJ0753 Attn: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

TSTF Comments on Draft Model Safety Evaluation of Traveler TSTF-547, Revision 0, "Clarification of Rod Position Requirements," and Transmittal of TSTF-547, Revision 1

REFERENCE:

Letter from Michelle Honcharik (NRC) to the TSTF, "Draft Model Safety Evaluation of Technical Specifications Task Force Traveler TSTF-547, Revision 0, "Clarification of Rod Position Requirements," dated November 20, 2015 (ADAMS Accession No. ML15187A235).

On March 6, 2014, the TSTF submitted traveler TSTF-547, Revision 0, "Clarification of Rod Position Requirements," to the Nuclear Regulatory Commission (NRC) for review (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14065A582). In the referenced letter, the NRC provided for comment the draft model Safety Evaluation of TSTF-547.

Attachment 1 contains a summary table and mark-up providing the TSTF's comments on the draft model Safety Evaluation (SE).

The NRC has recently revised the approval process for TSTF travelers and will no longer publish a Notice of Availability in the Federal Register. This necessitates a revision to the model application contained in TSTF-547. Revision 1 of TSTF-547 is included in Attachment 2. The revisions to the model application are indicated by change bars in the right margin.

11921 Rockville Pike, Suite 100, Rockville, MD 20852 Phone: 301-984-4400, Fax: 301-984-7600 Administration by EXCEL Services Corporation

TSTF 15-13 DATE Page 2 Should you have any questions, please do not hesitate to contact us.

James R. Morris (PWROG/W) Joseph A. Clark (BWROG)

Otto W. Gustafson (PWROG/CE) Henry L. Hegrat (PWROG/B&W) - TSTF Comments on the Model Safety Evaluation - TSTF-547, Revision 1 cc: Michelle Honcharik, Licensing Processes Branch, NRC Robert Elliott, Technical Specifications Branch, NRC

TSTF 15-13 DATE Page 3 Attachment 1 TSTF Comments on the Model Safety Evaluation Summary Table of TSTF Comments Section Comment 2.1 Fourth paragraph. The description should be revised to differentiate between Digital Rod Position Indication (DRPI) and the more generic term Rod Position Indication (RPI). In the first sentence, change "Digital Rod Position Indication (DRPI)" to "Rod Position Indication (RPI)." In the seventh, ninth, and tenth sentences, change references to "DRPI" to "RPI". Add the following sentence to the end of the paragraph, "Depending on the plant design, the RPI system may be analog or digital.

The digital system is called the Digital Rod Position Indication (DRPI) system. In the STS, the acronym "[D]RPI" is used to indicate either system design."

2.2 First sentence. Change "STSs" to "STS". The acronym is already plural (Standard Technical Specifications).

2.2.2 Penultimate paragraph, first sentence. Delete bracket before "12".

2.2.2 Penultimate paragraph, second sentence. For clarity, add "proposed to be" before the word modified to indicate that it is describing the proposed change.

2.2.3 Last paragraph, second sentence. Change "RPIs" to "[D]RPIs" for consistency with the rest of the document.

3.2 Second paragraph, first sentence. Change "DRPI" to "[D]RPI" for consistency with the rest of the document.

3.2 Third paragraph, first sentence. Change "RPI" to "[D]RPI" for consistency with the rest of the document.

Draft Model Safety Evaluation Mark-Up DRAFT SAFETY EVALUATION OF TECHNICAL SPECIFICATIONS TASK FORCE TRAVELER TSTF-547, REVISION 0, "CLARIFICATION OF ROD POSITON REQUIREMENTS"

1.0 INTRODUCTION

By letter dated March 6, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14065A582), the Technical Specifications (TS) Task Force (TSTF) submitted Traveler TSTF-547, Revision 0, "Clarification of Rod Position Requirements," for U.S. Nuclear Regulatory Commission (NRC) review and approval. Traveler TSTF-547 proposes changes to Volumes 1 and 2 of NUREG-1431, Revision 4, "Standard Technical Specifications: Westinghouse Plants," dated April 30, 2012 (ADAMS Accession No. ML12100A222 and ML12100A228, respectively).

The proposed changes would revise the standard technical specifications (STS) to provide time to correct rod movement failures that do not affect operability, provide an alternative to frequent verification of rod position using the movable incore detectors, and allow time for thermal equilibrium of analog rod position indication. The proposed changes would also align requirements of TS 3.1.4, "Rod Group Alignment Limits," and TS 3.1.7, "Rod Position Indication," eliminate an unnecessary Required Action (RA) from TS 3.1.7, and make some editorial improvements to TSs 3.1.4, 3.1.5, "Shutdown Bank Insertion Limits," 3.1.6, "Control Bank Insertion Limits," and 3.1.7.

2.0 REGULATORY EVALUATION

2.1 Description of Rod Cluster Control Assemblies The rod cluster control assemblies (RCCA), or rods, are moved by their control rod drive mechanisms (CRDM). Each CRDM moves its RCCA one step (approximately 5/8 inch) at a time, but at varying rates (steps per minute) depending on the signal output from the Rod Control System. The RCCAs are divided among control banks and shutdown banks. Each bank may be further subdivided into two groups to provide for precise reactivity control. A group consists of two or more RCCAs that are electrically paralleled to step simultaneously. If a bank of RCCAs consists of two groups, the groups are moved in a staggered fashion, but always within one step of each other. All units have four control banks and at least two shutdown banks.

The shutdown banks are maintained either in the fully inserted or fully withdrawn position. The control banks are moved in an overlap pattern, using the following withdrawal sequence: When control bank A reaches a predetermined height in the core, control bank B begins to move out with control bank A. Control bank A stops at the position of maximum withdrawal, and control bank B continues to move out. When control bank B reaches a predetermined height, control bank C begins to move out with control bank B. This sequence continues until control banks A, B, and C are at the fully withdrawn position, and control bank D is approximately halfway withdrawn. The insertion sequence is the opposite of the withdrawal sequence. The control rods

are arranged in a radially symmetric pattern, so that control bank motion does not introduce radial asymmetries in the core power distributions.

The control banks are used for precise reactivity control of the reactor. The positions of the control banks are normally automatically controlled by the Rod Control System, but they can also be manually controlled. They are capable of adding negative reactivity very quickly (compared to borating). The control banks must be maintained above designed insertion limits and are typically near the fully withdrawn position during normal full power operations.

The axial position of shutdown rods and control rods is indicated by two separate and independent systems, which are the Bank Demand Position Indication System (commonly called group step counters) and the Digital Rod Position Indication (DRPI) System. The Bank Demand Position Indication System counts the pulses from the rod control system that moves the rods.

There is one step counter for each group of rods. Individual rods 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 Bank Demand Position Indication System is considered highly precise (+/- 1 step or +/- 5/8 inch). If a rod does not move one step for each demand pulse, the step counter will still count the pulse and incorrectly reflect the position of the rod. The DRPI System provides a highly accurate indication of actual rod position, but at a lower precision than the step counters. This system is based on inductive analog signals from a series of coils spaced along a hollow tube. To increase the reliability of the system, the inductive coils are connected alternately to data system A or B. Thus, if one data system fails, the DRPI will go on half accuracy. The DRPI System is capable of monitoring rod position within at least +/- 12 steps with either full accuracy or half accuracy. Depending on the plant design, the RPI system may be analog or digital. The digital system is called the Digital Rod Position Indication (DRPI) system.

In the STS, the acronym "[D]RPI" is used to indicate either system design.

The shutdown margin (SDM) is defined in NUREG-1431 as the instantaneous amount of reactivity by which the reactor is subcritical or would be subcritical from its present condition assuming:

a. All RCCAs are fully inserted except for the single RCCA of highest reactivity worth, which is assumed to be fully withdrawn. However, with all RCCAs verified fully inserted by two independent means, it is not necessary to account for a stuck RCCA in the SDM calculation.

With any RCCA not capable of being fully inserted, the reactivity worth of the RCCA must be accounted for in the determination of SDM, and

b. In Power Operation and Startup, the fuel and moderator temperatures are changed to the nominal zero power design level.

The Core Operating Limits Report (COLR) is defined in NUREG-1431 as the unit specific document that provides cycle specific parameter limits for the current reload cycle. These cycle specific parameter limits must be determined for each reload cycle in accordance with TS 5.6.3.

Plant operation within these limits is addressed in individual Specifications.

2.2 Description of Changes This safety evaluation addresses changes to the STSs governing rod group alignment limits (TS 3.1.4), shutdown bank insertion limits (TS 3.1.5), control bank insertion limits (TS 3.1.6),

and rod position indication instrumentation (TS 3.1.7). The specific changes are described in the following subsections.

2.2.1 Provide Time to Correct Rod Movement Failures that Do Not Affect Operability The limiting condition for operation (LCO) 3.1.5 requires that each shutdown bank be within required insertion limits. Current Condition A for one or more shutdown banks not within the limits, requires:

A.1.1 Verify SDM is within the limits specified in the COLR within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

OR A.1.2 Initiate boration to restore SDM to within limit within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

AND A.2 Restore shutdown banks to within limits 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

LCO 3.1.6 requires that each control bank be within required insertion limits. Current Condition A for control bank insertion limits not met requires:

A.1.1 Verify SDM is within the limits specified in the COLR within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

OR A.1.2 Initiate boration to restore SDM to within limit within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

AND A.2 Restore control banks to within limits 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

The proposed change would add a new Condition A to LCO 3.1.5 that would require, with one shutdown bank inserted [16] steps beyond the insertion limits specified in the COLR:

A.1 Verify all control banks are within the insertion limits specified in the COLR within one hour.

AND A.2.1 Verify SDM is within the limits specified in the COLR within one hour.

OR A.2.2. Initiate boration to restore SDM to within the limit within one hour.

AND A.3 Restore the shutdown bank to within the insertion limits specified in the COLR within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The existing Condition A would be renumbered as Condition B and would be modified to apply for one or more shutdown banks not within limits for reasons other than Condition A. The existing RAs A.1.1, A.1.2, and A.2 would be renumbered B.1.1, B.1.2, and B.2. The existing Condition B and RA B.1 would be renumbered Condition C and RA C.1.

The proposed change would add a new Condition A to LCO 3.1.6 that would require control bank A, B, or C to be inserted [16] steps beyond the insertion, sequence, and overlap limits specified in the COLR to:

A.1 Verify all shutdown banks are within the insertion limits specified in the COLR within one hour.

AND A.2.1 Verify SDM is within the limits specified in the COLR within one hour.

OR A.2.2. Initiate boration to restore SDM to within the limit within one hour.

AND A.3 Restore the control bank to within the insertion, sequence, and overlap limits specified in the COLR within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The existing Condition A would be renumbered as Condition B and would be modified to apply for control bank insertion limits not met for reasons other than Condition A. The existing RAs A.1.1, A.1.2, and A.2 would be renumbered B.1.1, B.1.2, and B.2.

The existing Condition B would apply when control bank sequence or overlap limits are not met.

Condition B would be modified to apply when control bank sequence or overlap limits are not met for reasons other than Condition A. Existing Condition B and RAs B.1.1, B.1.2, and B.2 would be renumbered as Condition C and RAs C.1.1, C.1.2, and C.2. Existing Condition C and RA C.1 would be renumbered as Condition D and RA D.1.

The shutdown banks must be within their insertion limits any time the reactor is critical or approaching criticality. This ensures that a sufficient amount of negative reactivity is available to shut down the reactor and maintain the required SDM following a reactor trip.

The limits on control banks sequence, overlap, and physical insertion, as defined in the COLR, must be maintained because they serve the function of preserving power distribution, ensuring that the SDM is maintained, ensuring that ejected rod worth is maintained, and ensuring adequate negative reactivity insertion is available on trip.

2.2.2 Provide an Alternative to Frequent Verification of Rod Position Using the Movable Incore Detectors LCO 3.1.7, "Rod Position Indication," requires that the [D]RPI and the Demand Positon Indication System be operable during Startup and Power Operation. Condition A applies for one

[D]RPI per group of rods inoperable for one or more groups of rods. The associated RAs are:

A.1 Verify the position of the rods with inoperable [D]RPI position indicators indirectly by using the movable incore detectors once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

OR A.2 Reduce thermal power to 50 percent rated thermal power within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

The proposed change would add two new RAs to Condition A as alternatives to the once-per-8-hour indirect determination of rod position. The revised RAs would be:

A.1 Verify the position of rods with inoperable [D]RPI indirectly by using the moveable incore detectors once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> OR A.2.1 Verify the position of rods with inoperable [D]RPI indirectly by using the moveable incore detectors within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, once per 31 days of full power operation thereafter, within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after discovery of each unintended rod movement, within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after each movement of rods with inoperable [D]RPI > [12] steps, prior to exceeding 50 percent rated thermal power and within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after reaching rated thermal power.

AND A.2.2 Restore inoperable [D]RPI to operable status prior to entering Startup from Hot Standby OR A.3 Reduce thermal power to 50 percent rated thermal power The 12-step agreement limit between the Bank Demand Position Indication System and the

[D]RPI System indicates that the Bank Demand Position Indication System is adequately calibrated, and can be used for indication of the measurement of control rod bank position.

When one [D]RPI channel per group fails, the position of the rod may still be determined indirectly by use of the movable incore detectors.

SR 3.1.4.1 requires verification that the individual rods are within the alignment limit every

[12 hours or in accordance with the Surveillance Frequency Control Program. This SR is proposed to be modified by a Note to indicate that the SR is not applicable for rods with an inoperable [D]RPI.

Verification that individual rod positions are within alignment limits at a Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> provides a history that allows the operator to detect a rod that is beginning to deviate from its expected position. The specified Frequency takes into account other rod position information that is continuously available to the operator in the control room, so that during actual rod motion, deviations can immediately be detected. Alternatively, the SR frequency may be controlled by the Surveillance Frequency Control Program.

2.2.3 Allow Time for Thermal Equilibrium of Analog RPI The accuracy of the analog RPI system is affected by rod temperatures. With this effect, movement of associated rods may make the indications of the analog RPI system inaccurate.

The proposed revision would allow a 1-hour period for the drive shaft to reach thermal equilibrium following rod movement to ensure the accuracy of the RPI analog indications, prior to requiring verification of compliance with TS limits. This change affects SR 3.1.4.1, SR 3.1.5.1, SR 3.1.6.2, SR 3.1.6.3, and LCO 3.1.7, and is only applicable to analog RPIs.

SR 3.1.4.1 requires verification that individual rods are within the alignment limits every

[12 hours or in accordance with the Surveillance Frequency Control Program]. The proposed change adds a Note to the Surveillance that states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]"

SR 3.1.5.1 requires verification that each shutdown bank is within the insertion limits every

[12 hours or in accordance with the Surveillance Frequency Control Program]. The proposed change adds a Note to the Surveillance that states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]"

Since the shutdown banks are positioned manually by the control room operator, a verification of shutdown bank position at a frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, after the reactor is taken critical, is adequate to ensure that they are within their insertion limits. Also, the 12-hour frequency takes into account other information available in the control room for the purpose of monitoring the status of shutdown rods. Alternatively, the SR frequency may be controlled by the Surveillance Frequency Control Program.

SR 3.1.6.2 requires verification that each control bank is within the insertion limits every

[12 hours or in accordance with the Surveillance Frequency Control Program]. The proposed change adds a Note to the Surveillance that states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]"

Verification of the control bank insertion limits at a frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient to detect control banks that may be approaching the insertion limits since, normally, very little rod motion occurs in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Alternatively, the SR frequency may be controlled by the Surveillance Frequency Control Program.

SR 3.1.6.3 requires verification that each control bank that is not fully withdrawn from the core is within the sequence and overlap limits every [12 hours or in accordance with the Surveillance Frequency Control Program]. The proposed change adds a Note to the Surveillance that states,

"[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]"

When control banks are maintained within their insertion limits as verified by SR 3.1.6.2, it is unlikely that their sequence and overlap will not be in accordance with requirements provided in the COLR. A frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is consistent with the insertion limit verification in SR 3.1.6.2. Alternatively, the SR frequency may be controlled by the Surveillance Frequency Control Program.

LCO 3.1.7, "Rod Position Indication," requires that the [D]RPI and the Demand Positon Indication System be operable during Startup and Power Operation. LCO 3.1.7 is revised to add a Note that states individual [D]RPIs are not required to be Operable following movement of associated rods.

2.2.4 Clarify SRs in TS 3.1.4 and TS 3.1.7 SR 3.1.4.1 requires verification of individual rod positions are within the alignment limits once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or in accordance with the Surveillance Frequency Control Program. The proposed change is the addition of a Note to SR 3.1.4.1 stating that the SR is not required to be performed for rods associated with an inoperable demand position indicator. This Note is being added because SR 3.1.4.1 cannot be performed for rods with an inoperable demand position indicator.

LCO 3.1.4 specifies that all shutdown and control rods shall be operable and individual indicated rod positions shall be within 12 steps of their group step counter demand position. SR 3.1.7.1 requires verification that each [D]RPI agrees within the required steps of the group demand position for the [full indicated range] of rod travel. The proposed change is the addition of a Note to SR 3.1.7.1 stating that the SR would not be required to be met for rods known not to meet LCO 3.1.4.

2.2.5 Eliminate an Unnecessary RA from TS 3.1.7 LCO 3.1.7, "Rod Position Indication," requires that the [D]RPI and the Demand Positon Indication System be operable during Startup and Power Operation. Condition B, is applicable when more than one [D]RPI per group is inoperable. Existing RA B.2 states, "Monitor and Record Reactor Coolant System Tavg."

RA B.2 is proposed to be deleted.

The existing RA B.3 is also being deleted as described below in Section 2.2.6, Item 5. Existing RA B.4 is being renumbered as B.2.

2.2.6 Other Proposed Changes The proposed changes described in this section are editorial and do not change the technical content and are therefore acceptable.

1. LCO 3.1.4, Condition B, is revised to eliminate RA B.1 and to combine RAs B.2.4 and B.2.5. Condition B applies when one rod is not within the alignment limits and RA B.1 requires restoring the rod to within limits within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. An alternative set of RA is provided in the RA section, and will continue to be required when Condition B is applicable. RA B.1 is an Action that requires restoration of equipment such that the Condition does not apply. Restoring equipment to operable status is understood to be an option. Therefore, stating this as an RA is not necessary.

2. LCO 3.1.5 and LCO 3.1.6 contain a note modifying the Applicability that states "This LCO is not applicable while performing SR 3.1.4.2." The proposed change moves the LCO 3.1.5 and LCO 3.1.6 Applicability Notes to LCO Notes and revises the Notes to state, "Not applicable to shutdown banks inserted while performing SR 3.1.4.2" for

LCO 3.1.5 and "Not applicable to control banks inserted while performing SR 3.1.4.2" for LCO 3.1.6. This change clarifies the note and does not alter its meaning.

3. TS 3.1.7 is revised to consistently use the defined abbreviation "[D]RPI." This affects the Actions Note, RA A.1, RA B.2, and RA C.1.

4. TS 3.1.7, Condition A, is revised from "for one or more groups" to the more standard terminology "in one or more groups," and TS 3.1.7, Condition B is revised to include the phrase "in one or more groups" to be more consistent with the wording of Condition A.

5. TS 3.1.7, RA B.3 is redundant to RA A.1. RA B.3 is proposed to be deleted.

Condition A applies when one [D]RPI per group is inoperable and Condition B applies when more than one [D]RPI per group is inoperable. Each entry into Condition B also requires entry into Condition A. Restating the RA is not necessary.

6. TS 3.1.7, Condition C is revised to contain similar terminology to Conditions A and B.

The existing Condition C states, "One or more rods with inoperable position indicators have been moved > 24 steps in one direction since the last determination of the rod's position." Conditions A and B are worded such that the condition describing the inoperable equipment (e.g., "One [D]RPI per group inoperable...") is listed first. The proposed change rewords Condition C to state, "One or more [D]RPI inoperable in one or more groups and associated rods have been moved >24 steps in one direction since the last position determination."

7. LCO 3.1.7, Condition D is revised from "One demand position indicator per bank inoperable for one or more banks" to "One or more demand position indicators per bank inoperable in one or more banks." The proposed change makes the terminology consistent with the Note modifying the RAs.

The current TS 3.1.7 is modified by a Note which states, "Separate Condition entry is allowed for each inoperable rod position indicator and each demand position indicator."

The Bases for the Note states that the Note is acceptable because the RAs for each condition provide appropriate compensatory actions for each inoperable indicator.

There is one demand position indicator per group of rods. For banks with two groups of rods, there are two demand indicators per bank. The separate condition entry Note modifying the TS 3.1.7 Actions states that separate condition entry is allowed for inoperable demand position indicators which means that the Condition D is applicable to more than one inoperable demand position indicator per bank. The proposed change makes the existing Condition D terminology consistent with the Note.

2.3 Regulatory Review The categories of items required to be in the TSs are provided in Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36(c). As required by 10 CFR 50.36(c)(2)(i), the TSs will include LCOs, which are the lowest functional capability or performance levels of equipment

required for safe operation of the facility. Per 10 CFR 50.36(c)(2)(i), when an LCO of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the TSs until the condition can be met. The regulation at 10 CFR 50.36(c)(3) requires TSs to include items in the category of SRs, which are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the LCOs will be met.

Also, 10 CFR 50.36(a)(1) states that a summary statement of the bases or reasons for such specifications, other than those covering administrative controls, shall also be included in the application, but shall not become part of the TSs.

The NRC staffs guidance for review of TSs is in Chapter 16, Technical Specifications, of NUREG-0800, Revision 3, Standard Review Plan (March 2010) (ADAMS Accession No. ML100351425). As described therein, as part of the regulatory standardization effort, the NRC staff has prepared STS for each of the light-water reactor nuclear designs. NUREG-1431 contains the STS for Westinghouse-designed plants.

3.0 TECHNICAL EVALUATION

The NRC staff reviewed the proposed changes to NUREG-1431 and the technical justification for the changes provided in Traveler TSTF-547. The NRC staff reviewed the technical justification for the proposed changes to ensure the reasoning was logical, complete and clearly written as described in Chapter 16 of NUREG-0800. The NRC staff reviewed the proposed changes for continued compliance with the requirements of 10 CFR 50.36 and for consistency with conventional terminology and with the format and usage rules embodied in the STS. The NRC staff considered whether there should be any limitations or conditions placed on adoption of the Traveler by future applicants.

Although the TS bases are not part of the TS, the staff confirmed that that TS bases described the basis for each revised TS requirement accurately as described in Chapter 16 of NUREG-0800.

3.1 Provide Time to Correct Rod Movement Failures that Do Not Affect Operability Review The proposed new Condition A of TSs 3.1.5 and 3.1.6 for shutdown and control bank insertion limits, would allow 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore a single bank to be within its insertion limit when inserted below the insertion limit. With one shutdown or control bank inserted a maximum of [16] steps below the rod insertion limit, the RAs associated with new Condition A also require verification that all control or shutdown banks are within the insertion limits; and verification that the reactor can be shutdown using control rods or boration. The Completion Time for these RAs is 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

The new conditions define limits of both duration and insertion if a bank is immovable due to failures external to the CRDM. A maximum of one control or shutdown bank may be inserted beyond the limits for a maximum of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided all other banks are within the insertion limits and that the reactor could be shut down using control rods. The new Condition A imposes a limit on the insertion of [16] steps less than the insertion limit. The value of [16] steps corresponds to the minimum number of steps that the rods must be moved to ensure correct performance of SR 3.1.4.2. NOTE: The minimum number of steps that the rods must be moved

to ensure correct performance of SR 3.1.4.2 is typically 16 steps but the number of steps varies by plant.

The NRC staff reviewed the justification for the proposed addition of Condition A to TS 3.1.5 and TS 3.1.6 provided in the Technical Evaluation Section of Traveler TSTF-547, to ensure the reasoning is logical, complete and clearly written. The justification in Traveler TSTF-547 states:

1. All control and shutdown rod assemblies are required to be Operable. If a rod is untrippable (i.e., inoperable), then a plant shutdown is required in accordance with LCO 3.1.4, Condition A.

2. Only one control bank and shutdown bank may be inserted beyond insertion limits by more than [16] steps. If one or more control banks or shutdown banks exceed the insertion limit, a brief time period is permitted to correct the condition and then a plant shutdown is required.

3. If one rod is not within the alignment limits, adequate SDM is verified and a power reduction is required by LCO 3.1.4, Condition B. If more than one rod is not within the alignment limit, adequate SDM is verified and a plant shutdown is required.

The insertion limits are established to ensure a sufficient amount of negative reactivity can be rapidly inserted to shutdown the reactor. The NRC staff finds that allowing continued full-power operations for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with a rod movement failure is acceptable for the following reasons:

(1) The Shutdown Margin continues to be met (2) all control and shutdown rods are trippable - i.e., capable of being rapidly inserted into the core (3) only one bank may exceed insertion limits by no more than a specified number of steps (4) all immovable rod assemblies are aligned, and (5) the rods must be restored to within the insertion limits within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The change to TS 3.1.5 and TS 3.1.6 to provide time to correct rod movement failures that do not affect Operability will allow sufficient time for diagnosis and repairs while maintaining the safety function of the control rods since the affected rods are still trippable. In addition, alignment must be maintained and it will be verified that the reactor could still be shutdown.

Therefore, the NRC staff has determined that the proposed 24-hour completion time for Condition A in LCO 3.1.5 and 3.1.6 specifying shutdown bank and control bank insertion limits is acceptable.

The NRC staff concludes that TS 3.1.5 and TS 3.1.6, as modified by the addition of Condition A, continue to specify the minimum performance level of equipment needed for safe operation of the facility as a LCO; and continue to specify the appropriate remedial measures if the LCO is not met. SRs are not being changed by the addition of Condition A. The NRC staff finds that the requirements of 10 CFR 50.36(c)(2) continue to be met because the minimum performance

level of equipment needed for safe operation of the facility is contained in the LCO and the appropriate remedial measures are specified if the LCO is not met.

3.2 Provide an Alternative to Frequent Verification of Rod Position Using the Movable Incore Detectors Review LCO 3.1.7 requires that the [D]RPI and the Demand Position Indication System be Operable in during Power Operation and Startup. When one or more [D]RPI are inoperable, current TS 3.1.7 requires verification of rod position once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> using the movable incore detector system or reduce thermal power to less than or equal to 50 percent rated thermal power (RTP) within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The proposed change provides an alternative set of RAs.

New RA A.2.1 requires use of the movable detector system to monitor the position of the rod within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the inoperability of [D]RPI, 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after discovery of each unintended rod movement, 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after each greater than 12 step movement of a rod with inoperable [D]RPI, prior to exceeding 50 percent RTP, 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after reaching RTP, and once per 31 effective full power days (EFPD) thereafter. New RA A.2.2 would require the inoperable [D]RPI to be restored to Operable status prior to entering Startup from Hot Standby.

The implementation of new RAs A.2.1 and A.2.2 would allow use of an alternative monitoring scheme until the next shutdown, after which the [D]RPI must be restored to an Operable status.

The NRC staff finds that the new RAs A.2.1 and A.2.2 and Completion Times are more appropriate because they require verification of rod position following circumstances in which rod motion could occur. This is more appropriate compared to current TS 3.1.7 RA A.1, which requires verification of rod position using the moveable incore detection system once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, regardless of whether the rods have moved or not. Additionally, the new RAs A.2.1 and A.2.2 contain a requirement to restore the [D]RPI to operable status prior to restart.

If the rod position indication is failed for an individual rod, its position is determined indirectly by use of the moveable incore detectors. The NRC staff has determined that the change to verify rod position using the movable incore detectors based on the occurrence of events requiring rod motion, rather than determining position on a specified frequency, is acceptable because events requiring rod motion of the shutdown banks and control banks A, B, and C are relatively infrequent during steady state operation. Events involving significant movement of rods in control bank D are also relatively infrequent. The indirect determination of rod position is required after significant changes in power level or following substantial rod motion.

The addition of the Note to SR 3.1.4.1 to state that the SR is not required to be performed for rods associated with an inoperable [D]RPI is appropriate because the RAs of TS 3.1.7 for an inoperable [D]RPI provide the appropriate actions for indirectly determining the position of the affected rods.

The NRC staff concludes that the addition of an alternative monitoring scheme to indirectly determine the position of rods associated with an inoperable [D]RPI is acceptable. TS 3.1.7, as modified, continues to specify the minimum performance level of equipment needed for safe operation of the facility as an LCO and continues to specify the appropriate remedial measures if

the LCO is not met. The revised SR 3.1.4.1, which has been clarified to specify when it is required to be performed, continues to be an appropriate test to ensure the necessary quality of systems is maintained. The NRC staff finds that the requirements of 10 CFR 50.36(c)(2) continue to be met because the minimum performance level of equipment needed for safe operation of the facility is contained in the LCO and the appropriate remedial measures are specified if the LCO is not met. The NRC staff finds that the requirements of regulations of 10 CFR 50.36(c)(3) continue to be met because the revised SR provides the appropriate testing to ensure the necessary quality of components is maintained and that the LCO will be met.

3.3 Allow Time for Thermal Equilibrium of Analog RPI Review Several changes are proposed to allow a 1-hour period for the drive shaft to reach thermal equilibrium following rod movement to ensure accuracy of the RPI analog indications to verify TS limits. LCO 3.1.7 would be revised with a Note that individual RPIs are not required to be operable for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following rod motion. SRs 3.1.4.1, 3.1.5.1, 3.1.6.2 and 3.1.6.3 would be revised to not be required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after the associated rod motion.

The 1-hour period is based on the necessary time to allow the rod drive shaft to reach thermal equilibrium following rod motion. There are thermal effects which cause the analog position indicators to drift following rod motion. During this period prior to establishment of thermal equilibrium, the indicators could be unstable and could indicate an inaccurate rod position.

During this 1-hour period, the Demand Position Indication System would be available to indicate the demand position of the rods.

The NRC staff reviewed the technical justification provided in the Traveler TSTF-547 to ensure the reasoning is logical, complete and clearly written as described in Chapter 16 of NUREG-0800.

The NRC staff concludes that TS 3.1.7, as modified by the addition of a Note, continues to specify the minimum performance level of equipment needed for safe operation of the facility, and continues to specify the appropriate remedial measures if the LCO is not met. The changes to the SRs ensure the SRs are performed when the position indication system has achieved thermal stability following rod motion. The SRs would continue to ensure the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and the limiting conditions for operation will be met. The NRC staff finds that the requirements of 10 CFR 50.36(c)(2) continue to be met.

3.4 Clarify SRs in TS 3.1.4 and TS 3.1.7 Review 3.4.1 Clarification of SR 3.1.4.1 LCO 3.1.4 requires that all shutdown and control rods shall be operable and individual indicated rod positions shall be within 12 steps of their group step counter demand position. SR 3.1.4.1 requires verification of the individual rod positions within the alignment limit periodically.

SR 3.1.4.1 cannot be performed for rods with an inoperable bank demand position indicator.

Failure to meet an SR is considered a failure to meet an LCO requirement. Therefore, if

SR 3.1.4.1 cannot be performed, entry is required into LCO 3.1.4 Condition D. LCO 3.1.4 Condition D applies when more than one rod is not within the alignment limit. The RA associated with Condition D requires, in part, that the reactor be in Hot Standby within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

LCO 3.1.7 requires the [D]RPI and bank demand position indication to be operable. LCO 3.1.7 Condition D applies if one demand position indicator per band is inoperable for one or more banks. The Condition D RAs require verification that all [D]RPIs for the affected banks are operable and verify the most withdrawn rod and least withdrawn rod of the affected banks are less than or equal to [12] steps apart once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Alternatively, thermal power must be reduced to less than or equal to 50 percent RTP.

A Note is being added to SR 3.1.4.1 stating that this SR is not required to be performed for rods associated with an inoperable demand position indicator. The alignment limit is based on the demand position indicator. If the bank demand position indicator is inoperable, the SR cannot be performed.

Following modification of SR 3.1.4.1, Condition D of LCO 3.1.7 would be the applicable Condition to be entered in the event of inoperable demand position indicators. The RAs associated with Condition D of LCO 3.1.7 provide the appropriate actions in this situation by requiring that the [D]RPIs are operable and that the individual rods in the bank are not misaligned by more than [12] steps.

3.4.2 Clarification of SR 3.1.4.1 and SR 3.1.7.1 LCO 3.1.4 requires that all shutdown and control rods shall be operable and individual indicated rod positions shall be within 12 steps of their group step counter demand position.

LCO 3.1.7 requires the [D]RPI and bank demand position indication to be operable.

SR 3.1.7.1 requires verification that each [D]RPI agree within [12] steps of the group demand position for the [full indicated range] of rod travel. This SR is performed once prior to criticality after each removal of the reactor head. Failure to meet an SR is considered a failure to meet the LCO per SR 3.0.1. The requirements of SRs must be satisfied in between performances of the surveillance test itself. If a control or shutdown rod is not within 12 steps of its bank demand position indication, then the requirements of both LCO 3.1.4 and LCO 3.1.7 are not met.

A Note is being added to SR 3.1.7.1 stating that this SR is not required to be performed for rods that are known not to meet LCO 3.1.4. If a rod is known not to be within [12] steps of the group demand position, LCO 3.1.4 provides the appropriate RAs. With one rod not within the alignment limit, Condition B requires either (1) verification of shutdown margin or boration until SDM is met; and a reduction in RTP or by (2) verification of shutdown margin or boration until SDM is met, hot channel factors must be verified within limits, and safety analyses must be re-evaluated to confirm continued operation is permissible. If more than one rod is misaligned, the SDM must be determined by requiring verification that the shutdown margin is within limits or initiate boration to restore required SDM and shutdown the plant.

The NRC staff reviewed the technical justification for the proposed changes provided in the Traveler TSTF-547 for logical reasoning, completeness and clarity. The purpose of the changes is to prescribe the appropriate Actions to be followed when equipment is inoperable.

TS 3.1.4 provides limits on rod alignment to ensure acceptable power peaking factors and local linear heat rates and an acceptable shutdown margin, all of which are initial conditions in the applicable safety analyses. It is appropriate to consolidate requirements associated with rod misalignments in this TS. TS 3.1.7 provides requirements for instrumentation to monitor rod position. The instrumentation is used to verify that the rod alignment limits in TS 3.1.4 are satisfied. Similarly, it is appropriate to consolidate requirements associated with instrumentation operability in this TS.

The NRC staff concludes that the clarifications to SRs 3.1.4.1 and 3.1.7.1 to specify configurations in which performance of the SRs is not required are appropriate. The TSs, as modified, continue to specify the minimum performance level of equipment needed for safe operation of the facility as an LCO, and continue to specify the appropriate remedial measures if the LCO is not met. The revised SRs 3.1.4.1 and 3.1.7.1 continue to be appropriate, because they ensure the necessary quality of systems is maintained. The NRC staff finds that the requirements of 10 CFR 50.36(c)(2) and 10 CFR 50.36(c)(3) continue to be met.

3.5 Eliminate an Unnecessary RA from LCO 3.1.7 Review The NRC staff reviewed the justification for deletion of LCO 3.1.7, RA B.2 that monitors and records reactor coolant average temperature (Tavg). RA B.2 is one of the RAs associated with LCO 3.17 Condition B. Condition B applies when more than one [D]RPI per group is inoperable in one or more groups. RA B.1 requires that the control rods be placed in manual control immediately and existing RA B.4 (renumbered as B.2) requires restoring the inoperable position indicators to operable status such that a maximum of one [D]RPI per group is inoperable within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The NRC staff has determined that RA B.2 provides no safety benefit for identifying trends in reactor coolant Tavg. This RA was intended to help assure that significant changes in power distribution and the ability to shutdown the reactor are avoided. During normal steady state power operation, there is very little rod motion. LCO 3.1.7 RA B.1 and RA B.4 (renumbered as RA B.2) continue to apply when more than one [D]RPI per group is inoperable. LCO 3.1.4 and LCO 3.1.7 provide the appropriate requirements for monitoring rod position and alignment and provide the appropriate actions, if a rod is misaligned. This provides the necessary verification that SDM is maintained. The nuclear instrumentation monitors neutron flux in the core providing indication of changes in power distribution. Therefore, the NRC staff concludes that RA B.2 of LCO 3.1.7 is unnecessary and can be deleted.

The NRC staff concludes that the proposed changes to LCO 3.1.7 are acceptable because the LCO continues to specify the minimum performance level of equipment needed for safe operation of the facility. As described in the preceding paragraph the appropriate remedial measures are prescribed when the LCO is not met. SRs are not being changed by the deletion of RA B.2. The NRC staff finds that the requirements of 10 CFR 50.36(c)(2) continue to be met.

3.6 Other Proposed Changes The NRC staff found that the following changes are editorial in nature and do not change the TS requirements, and are therefore acceptable.

1. LCO 3.1.4, Condition B, is revised to eliminate RA B.1 and to combine RAs B.2.4 and B.2.5. Condition B applies when one rod is not within the alignment limits and RA B.1 requires restoring the rod to within limits within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. An alternative set of RAs is provided in the RA section, and will continue to be required when Condition B is applicable. RA B.1 is an Action that requires restoration of equipment such that the Condition does not apply. Restoring equipment to operable status is understood to be an option. Therefore, stating this as an RA is not necessary.

2. LCO 3.1.5 and LCO 3.1.6 contain a note modifying the Applicability that states "This LCO is not applicable while performing SR 3.1.4.2." The proposed change moves the LCO 3.1.5 and LCO 3.1.6 Applicability Notes to LCO Notes and revises the Notes to state, "Not applicable to shutdown banks inserted while performing SR 3.1.4.2" for LCO 3.1.5 and "Not applicable to control banks inserted while performing SR 3.1.4.2" for LCO 3.1.6. This change clarifies the note and does not alter its meaning.

3. TS 3.1.7 is revised to consistently use the defined abbreviation "[D]RPI." This affects the Actions Note, RA A.1, RA B.2, and RA C.1.

4. TS 3.1.7, Condition A, is revised from "for one or more groups" to the more standard terminology "in one or more groups," and TS 3.1.7, Condition B is revised to include the phrase "in one or more groups" to be more consistent with the wording of Condition A.

5. TS 3.1.7, RA B.3 is redundant to RA A.1. RA B.3 is proposed to be deleted.

Condition A applies when one [D]RPI per group is inoperable and Condition B applies when more than one [D]RPI per group is inoperable. Each entry into Condition B also requires entry into Condition A. Restating the RA is not necessary.

6. TS 3.1.7, Condition C, is revised to contain similar terminology to Conditions A and B.

The existing Condition C states, "One or more rods with inoperable position indicators have been moved > 24 steps in one direction since the last determination of the rod's position." Conditions A and B are worded such that the condition describing the inoperable equipment (e.g., "One [D]RPI per group inoperable...") is listed first. The proposed change rewords Condition C to state, "One or more [D]RPI inoperable in one or more groups and associated rods have been moved >24 steps in one direction since the last position determination."

7. LCO 3.1.7, Condition D, is revised from "One demand position indicator per bank inoperable for one or more banks" to "One or more demand position indicators per bank

inoperable in one or more banks." The proposed change makes the terminology consistent with the Note modifying the RAs.

The current TS 3.1.7 is modified by a Note which states, "Separate Condition entry is allowed for each inoperable rod position indicator and each demand position indicator."

The Bases for the Note states that the Note is acceptable because the RAs for each condition provide appropriate compensatory actions for each inoperable indicator.

There is one demand position indicator per group of rods, two demand indicators per bank in those banks with two groups. The separate condition entry Note modifying the TS 3.1.7 Actions states that separate condition entry is allowed for inoperable demand position indicators which means that Condition D is applicable to more than one inoperable demand position indicator per bank. The proposed change makes the existing Condition D terminology consistent with the Note.

The regulation at 10 CFR 50.36(a)(1) states, in part: "A summary statement of the bases or reasons for such specifications shall also be included in the application, but shall not become part of the technical specifications." Accordingly, along with the proposed STS changes, the TSTF also submitted STS Bases changes that corresponded to the proposed STS changes.

3.7 Summary of NRC Staff Conclusions The regulations at 10 CFR 50.36 require that TSs will include items in specified categories, including LCOs and SRs. The proposed changes modify the LCOs, Conditions, RAs, Completion Times, and SRs applicable to control rod and shutdown rod insertion and alignment limits and the instrumentation to monitor rod position and alignment. The STS continue to specify the LCOs and specify the remedial measures to be taken if one of these requirements is not satisfied. The STS continue to specify the appropriate SRs for tests and inspections to ensure the necessary quality of affected structures, systems and components is maintained. The NRC staff finds that the proposed LCOs, and SRs meet the requirements of 10 CFR 50.36(c)(2) and 50.36(c)(3), respectively.

Principal Contributor: M. Chernoff, DSS/STSB Date:

Attachment 2 TSTF-547, Revision 1

WOG-209, Rev. 1 TSTF-547, Rev. 1 Technical Specifications Task Force Improved Standard Technical Specifications Change Traveler Clarification of Rod Position Requirements NUREGs Affected: 1430 1431 1432 1433 1434 Classification: 1) Technical Change Recommended for CLIIP?: Yes Correction or Improvement: Improvement NRC Fee Status: Not Exempt Changes Marked on ISTS Rev: 4.0 See attached justification.

Revision History OG Revision 0 Revision Status: Closed Revision Proposed by: PWROG Revision

Description:

Original Issue Owners Group Review Information Date Originated by OG: 14-Nov-12 Owners Group Comments Following PWROG LSC review, the PWROG forwarded the draft Traveler to the Rod Control Working Group for review.

Owners Group Resolution: Superceeded Date: 29-May-13 OG Revision 1 Revision Status: Closed Revision Proposed by: WOG Revision

Description:

TSTF-547 was revised to reflect the comments of the Rod Control Working Group, as well as other changes.

Owners Group Review Information Date Originated by OG: 22-Jan-14 Owners Group Comments (No Comments)

Owners Group Resolution: Approved Date: 18-Feb-14 TSTF Review Information TSTF Received Date: 21-Feb-14 Date Distributed for Review 21-Feb-14 OG Review Completed: BWOG WOG CEOG BWROG TSTF Comments:

31-Dec-15 Copyright(C) 2015, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

WOG-209, Rev. 1 TSTF-547, Rev. 1 OG Revision 1 Revision Status: Closed (No Comments)

TSTF Resolution: Approved Date: 06-Mar-14 NRC Review Information NRC Received Date: 06-Mar-14 NRC Comments: Date of NRC Letter: 20-Nov-15 TSTF-547, Revision 0, model application to be revised to reflect the change in NRC processes.

Final Resolution: Superceded by Revision Final Resolution Date: 20-Nov-15 TSTF Revision 1 Revision Status: Active Revision Proposed by: TSTF Revision

Description:

The model application is revised to no longer refer to a Notice of Availability published in the Federal Register. Administrative improvements are made to the model application. The traveler justification and the TS and Bases markups are not changed. Changes in the model application are indicated by revision bars in the right margin.

TSTF Review Information TSTF Received Date: 11-Dec-15 Date Distributed for Review 11-Dec-15 OG Review Completed: BWOG WOG CEOG BWROG TSTF Comments:

(No Comments)

TSTF Resolution: Approved Date: 31-Dec-15 NRC Review Information NRC Received Date: 31-Dec-15 Affected Technical Specifications Action 3.1.4.B Rod Group Alignment Limits Action 3.1.4.B Bases Rod Group Alignment Limits SR 3.1.4.1 Rod Group Alignment Limits SR 3.1.4.1 Bases Rod Group Alignment Limits 31-Dec-15 Copyright(C) 2015, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

WOG-209, Rev. 1 TSTF-547, Rev. 1 LCO 3.1.5 Shutdown Bank Insertion Limits LCO 3.1.5 Bases Shutdown Bank Insertion Limits Appl. 3.1.5 Shutdown Bank Insertion Limits Appl. 3.1.5 Bases Shutdown Bank Insertion Limits Action 3.1.5.A Shutdown Bank Insertion Limits Change

Description:

New Action Action 3.1.5.A Shutdown Bank Insertion Limits Change

Description:

Renamed B and revised Action 3.1.5.A Bases Shutdown Bank Insertion Limits Change

Description:

New Action Action 3.1.5.A Bases Shutdown Bank Insertion Limits Change

Description:

Renamed B and revised Action 3.1.5.B Shutdown Bank Insertion Limits Change

Description:

Renamed C and revised.

Action 3.1.5.B Bases Shutdown Bank Insertion Limits Change

Description:

Renamed C and revised.

SR 3.1.5.1 Shutdown Bank Insertion Limits SR 3.1.5.1 Bases Shutdown Bank Insertion Limits LCO 3.1.6 Control Bank Insertion Limits LCO 3.1.6 Bases Control Bank Insertion Limits Appl. 3.1.6 Control Bank Insertion Limits Appl. 3.1.6 Bases Control Bank Insertion Limits Action 3.1.6.A Control Bank Insertion Limits Change

Description:

Renamed B and revised Action 3.1.6.A Control Bank Insertion Limits Change

Description:

New Action Action 3.1.6.A Bases Control Bank Insertion Limits Change

Description:

New Action Action 3.1.6.A Bases Control Bank Insertion Limits Change

Description:

Renamed B and revised Action 3.1.6.B Control Bank Insertion Limits Change

Description:

Renamed C 31-Dec-15 Copyright(C) 2015, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

WOG-209, Rev. 1 TSTF-547, Rev. 1 Action 3.1.6.B Bases Control Bank Insertion Limits Change

Description:

Renamed C Action 3.1.6.C Control Bank Insertion Limits Change

Description:

Renamed D Action 3.1.6.C Bases Control Bank Insertion Limits Change

Description:

Renamed D SR 3.1.6.2 Control Bank Insertion Limits SR 3.1.6.2 Bases Control Bank Insertion Limits SR 3.1.6.3 Control Bank Insertion Limits SR 3.1.6.3 Bases Control Bank Insertion Limits LCO 3.1.7 Rod Position Indication LCO 3.1.7 Bases Rod Position Indication Action 3.1.7 Rod Position Indication Change

Description:

Action Note Action 3.1.7.A Rod Position Indication Action 3.1.7.A Bases Rod Position Indication Action 3.1.7.B Rod Position Indication Action 3.1.7.B Bases Rod Position Indication Action 3.1.7.C Rod Position Indication Action 3.1.7.C Bases Rod Position Indication Action 3.1.7.D Rod Position Indication Action 3.1.7.D Bases Rod Position Indication 31-Dec-15 Copyright(C) 2015, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

TSTF-547, Rev. 1

1.

SUMMARY

DESCRIPTION The Westinghouse plant Standard Technical Specifications (STS) contain four specifications related to rod cluster control assemblies (herein referred to as "rods").

There are two specifications on rod bank insertion limits, one on rod insertion time and alignment, and one on rod position indication. Operating experience has identified several issues related to the interaction of these requirements, internal consistency, and system hardware. Individual licensees have requested license amendments to address some of these issues. This proposed change addresses these issues in an integrated fashion in order to improve plant safety, improve the consistency and presentation of the Technical Specifications (TS), to remove unnecessary operational impediments.

The proposed change makes the following revisions to the TS:

1. TS 3.1.5, "Shutdown Bank Insertion Limits," and TS 3.1.6, "Control Bank Insertion Limits," are revised to provide time to repair rod movement failures that do not affect rod Operability;

2. TS 3.1.7, "Rod Position Indication," is revised to provide an alternative to frequent use of the movable incore detector system when position indication for a rod is inoperable;

3. TS 3.1.4, "Rod Group Alignment Limits," TS 3.1.5, TS 3.1.6, and TS 3.1.7 are revised to provide time for analog position indication instruments to read accurately after rod movement;

4. TS 3.1.4 and TS 3.1.7 are revised to correct conflict between the requirements of the two TS;

5. TS 3.1.7 is revised to eliminate an unnecessary action; and

6. TS 3.1.4, TS 3.1.5, TS 3.1.6, and TS 3.1.7 are revised to increase consistency and to improve the presentation.

The TS Bases are revised to reflect the proposed changes.

A model application is included at Attachment 1. The model may be used by licensees adopting the proposed change following NRC approval.

2. DETAILED DESCRIPTION

Background

The rod cluster control assemblies (herein referred to as "rods") are divided among control banks and shutdown banks. Each bank may be further subdivided into two groups to provide for precise reactivity control. When a bank of rods consists of two groups they are moved in a staggered fashion, but always within one step of each other.

All Westinghouse-design plants have four control banks and at least two shutdown banks.

Page 1

TSTF-547, Rev. 1 The control banks are used for precise reactivity control of the reactor. The positions of the control banks are normally automatically controlled by the Rod Control System, but they can also be manually controlled. They are capable of adding negative reactivity very quickly (compared to adding soluble boron). The control banks must be maintained above the design insertion limits and three of the four control banks are typically near the fully withdrawn position during full power operations.

During a startup, the shutdown banks are withdrawn first. The shutdown banks are designed to be fully withdrawn without the core going critical. The shutdown banks are controlled manually by the control room operator. The shutdown banks must be completely withdrawn from the core prior to withdrawing any control banks during an approach to criticality. The shutdown banks are then left in this position until the reactor is shut down.

The rod insertion limits of the shutdown and control rods are initial assumptions in all safety analyses that assume rod insertion upon reactor trip. The insertion limits ensure sufficient shutdown margin (SDM) is available when required for a reactor shutdown.

The sequence and overlap limits on the control rods govern the withdrawal sequence and overlap of the control rod banks to ensure consistent reactivity changes due to rod movement. The alignment limits govern the position of individual rods with respect to each other to maintain a consistent power distribution across the reactor core.

The shutdown and control bank insertion and alignment limits, axial flux difference (AFD), and quadrant power tilt ratio (QPTR) are process variables that are used to monitor and control the three dimensional power distribution of the reactor core.

Additionally, the control bank insertion limits control the reactivity that could be added in the event of a rod ejection accident.

The TS requirements on rod alignment ensure that the assumptions in the safety analyses will remain valid. Mechanical or electrical failures may cause a rod to become inoperable (i.e., not trippable), unable to be moved, or to become misaligned from its group. The requirements on rod Operability ensure that on a reactor trip, the assumed reactivity will be inserted. Rod Operability requirements (i.e., trippability) are not dependent upon the alignment requirements, which ensure that the rods and banks maintain the correct power distribution and rod alignment. The rod Operability requirement is satisfied if the rod will fully insert in the required rod drop time assumed in the safety analyses. Rod control malfunctions that result in the inability to move a rod (e.g., rod lift coil failures), but that do not impact trippability, do not result in rod inoperability. The associated Limiting Condition for Operation (LCO) require both rod Operability (i.e., trippability) and rod alignment, and provide appropriate Required Actions when the LCO is not met.

The axial position of rods is indicated by two separate and independent systems, which are the Bank Demand Position Indication System (also called group step counters) and the Rod Position Indication System. There are two types of Rod Position Indication Systems and both are capable of monitoring rod position within at least +/- 12 steps. Older plants use an analog system (RPI) and newer plants use a digital RPI system (DRPI).

Page 2

TSTF-547, Rev. 1 When referring to either system, the acronym "[D]RPI" is used. The brackets surrounding the letter "D" indicate it is plant-specific.

The analog RPI system takes advantage of the fact that a transformer output will change if a piece of conducting metal is placed between the coils of the primary and secondary windings. The detector is a linear transformer that is mounted outside of the rod drive pressure housing. The rod drive shaft acts as the movable armature of the transformer and the position of the rod drive shaft within the rod position detector determines the amount of coupling between the primary and secondary windings. When a rod is withdrawn from the core, the relative permeability of the rod shaft causes an increase in the magnetic coupling between the primary and secondary windings. The magnitude of this secondary output is proportional to the actual rod position.

The digital RPI system consists of a stack of individual coils mounted outside the rod drive shaft. When the top of the rod drive shaft is located within a coil, the current flow through that coil increases and is greater than that of the adjacent coil. The voltages across the coils are continuously sampled.

The Bank Demand Position Indication System counts the pulses from the rod control system that moves the rods. There is one step counter for each group of rods. Individual rods 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 Bank Demand Position Indication System is highly precise (+/- 1 step), however, if a rod does not move one step for each demand pulse, the step counter will still count the pulse and incorrectly reflect the position of the rod.

Description of Proposed Change & Technical Evaluation

1. Provide Time to Correct Rod Movement Failures that Do Not Affect Operability This proposed change would add a new Condition A to LCO 3.1.5 and LCO 3.1.6 (shutdown and control bank insertion limits) that is applicable when one bank is inserted

[16] steps below the insertion limits specified in the Core Operating Limits Report (COLR). As stated in a proposed Reviewer's Note in the associated Bases, "The bracketed number [16] in Condition A should be replaced with the plant-specific minimum number of steps that the rods must be moved to ensure correct performance of Surveillance Requirement (SR) 3.1.4.2." The Condition provides 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore the single bank to within the insertion limit. Use of the limited period would be dependent on confirming that all other banks are within their insertion limits, and SDM is maintained or established.

LCO 3.1.5, Condition A, is renamed Condition B and the Condition is revised to append, "for reasons other than Condition A."

LCO 3.1.6, Conditions A and B, are renamed Conditions B and C, and the Conditions are revised to append, "for reasons other than Condition A."

Page 3

TSTF-547, Rev. 1 Technical Evaluation The control and shutdown rods primary function is to provide negative reactivity on a reactor trip. To verify that the rods are Operable (i.e., capable of being tripped),

SR 3.1.4.2 requires movement of the control and shutdown rods a minimum of 10 steps in either direction. For all control and shutdown banks other than Control Bank D, performance of the SR may be the only movement of the banks during a fuel cycle and, therefore, is the most likely occurrence of a rod control failure. Plants have occasionally experienced failures of the rod control system that result in an inability to move one or more rods via the rod control system, yet do not affect the rods ability to trip. An electrical rod controller failure (e.g., rod urgent failure) is a failure in the rod control equipment that can affect the ability of the system to move rods. Automatic rod motion and overlapped rod motion are stopped on receipt of an urgent failure alarm. The failure may occur in either the power cabinet or in the system logic cabinet. Such failures do not affect the ability of the rods to trip. In other words, the rods remain Operable.

To permit performance of SR 3.1.4.2, the Applicability section of LCO 3.1.5 and LCO 3.1.6 currently contain a Note stating that the LCO is not applicable during performance of the SR. The most likely occurrence of a failure that prevents movement of the rods is during performance of SR 3.1.4.2, when one or more rods may be outside the LCO 3.1.5 or LCO 3.1.6 insertion limits. Because the failure may preclude continued performance of SR 3.1.4.2, the allowance provided by the existing Applicability Notes no longer applies and existing Condition A of either LCO 3.1.5 or LCO 3.1.6 would require the bank to be restored to within limits in two hours. The failure may not be correctable within the two hour Completion Time, which would necessitate a TS-required shutdown even though the rods remained Operable (i.e., trippable) and the automatic bank overlap may not be available during the power reduction leading to shutdown. Providing a reasonable time to restore the ability to move the rods prior to initiating a plant shutdown prevents power changes without automatic rod overlap protection.

This proposed change would add a new Condition A to LCO 3.1.5 and LCO 3.1.6 that is applicable when one bank is inserted [16] steps below the insertion limit. The specific number of steps is bracketed and will be replaced with the plant-specific minimum number of steps that the rods must be moved to perform SR 3.1.4.2. The Condition provides 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore the bank to within the insertion limits. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period is sufficient to repair most rod control failures.

The shutdown and control rods, including the rods in the bank that do not meet the insertion limits specified in the COLR (as would be allowed by the proposed change),

must remain Operable (i.e., trippable) or a plant shutdown is required by LCO 3.1.4.

During the limited 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, adequate SDM is required to be verified or established by the Condition A Required Actions. In addition, if the LCO is not met for a shutdown bank, the control banks must be within the insertion limits. If the LCO is not met for a control bank, the shutdown banks must be within the insertion limits. These requirements ensure that the SDM assumed in the accident analyses is available and minimize the effect on core power distribution. While in the Condition, the TS Page 4

TSTF-547, Rev. 1 requirements on core power distribution (AFD, QPTR, nuclear enthalpy rise hot channel factor, and heat flux hot channel factor) continue to apply to ensure the core power distribution remains within the assumptions of the accident analysis.

The proposed change protects the assumptions in the safety analysis and reduces the likelihood of a plant shutdown without automatic rod bank overlap control, while providing a reasonable amount of time to repair a rod bank that cannot be moved.

2. Provide an Alternative to Frequent Verification of Rod Position Using the Movable Incore Detectors The rod control system and the [D]RPI system are used to ensure that rod alignment and insertion limits are maintained. Operators utilize the [D]RPI system to monitor the position of the rods to establish that the plant is operating within the bounds of the accident analysis assumptions. Operability (i.e., trippability) and position of the rods are an initial condition assumption in all safety analyses that assume rod insertion upon a reactor trip.

If one or more [D]RPIs are inoperable, TS 3.1.7 requires verification of the position of the associated rods using the movable incore detector system once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The proposed change revises TS 3.1.7 to provide an alternative to using the moveable incore detectors every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> (approximately 90 times per month) by utilizing a different monitoring method. This reduces the wear on the movable incore detector system. Wear of the movable incore detector system does not pose a reduction in the margin of safety, but excessive wear could result in a loss of functionality of the system. This could lead to the inability to complete required Surveillances and a plant shutdown.

The proposed change adds two new Required Actions to LCO 3.1.7 as an alternative to the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> monitoring in the existing Condition A Required Actions. Proposed Required Actions A.2.1 requires verification of the position of rods associated with an inoperable

[D]RPI using the moveable incore detector system and includes six Completion Times:

a. Initial verification within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the inoperability of the [D]RPI;

b. Re-verification once every 31 Effective Full Power Days (EFPD) thereafter;

c. Verification within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if rod control system parameters indicate unintended rod movement;

d. Verification within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if the rod with an inoperable [D]RPI is intentionally moved greater than 12 steps;

e. Verification prior to exceeding 50% RTP if power is reduced below 50%

RTP; and

f. Verification within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after reaching RTP.

Page 5

TSTF-547, Rev. 1 Required Action A.2.2 states that the inoperable [D]RPI must be restored to Operable status prior to entering MODE 2 from MODE 3. Existing Required Action A.2 is relabeled A.3.

A Note is added to SR 3.1.4.1 to accommodate the proposed alternative for verifying rod position.

Technical Evaluation New Required Action A.2.1 continues to use the movable detector system to monitor the position of the rod with the inoperable [D]RPI. Periodic verification is less frequent and additional verification is made following circumstances in which the rod may have moved. The initial position of the rod is determined within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and every 31 EFPD thereafter. The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> initial Completion Time is the same as existing Required Action A.1 and the 31 EFPD period coincides with the typical Frequency of power distribution Surveillances that utilize the movable incore detector system. If there is unintended movement of a rod or if a rod with an inoperable [D]RPI is moved more than 12 steps, the movable incore detectors are used to verify the rod position within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. If there are changes in core power, which could result in changes in rod position, the rod position must be verified before exceeding 50% RTP and within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of reaching full power.

This confirms the position of the rod with an inoperable [D]RPI to ensure that power distribution requirements are not violated and to establish a starting point for the proposed alternate monitoring actions.

New Required Action A.2.2 requires the inoperable [D]RPI to be restored to Operable status prior to entering Mode 2 from Mode 3. This allows use of the alternative monitoring scheme until the next shutdown, after which the [D]RPI must be restored to Operable status.

The ability to immediately detect a rod drop or misalignment is not directly provided by the movable incore detectors used in current Required Action A.1, or by the alternate monitoring method proposed in Required Actions A.2.1 and A.2.2. However, should there be a drop of a rod, it will typically be detectable by the excore power range detectors. Additionally, a negative reactivity insertion corresponding to the reactivity worth of the dropped rod may cause a change in core parameters, such AFD and QPTR.

Note that the proposed Required Actions provide an alternative to the existing rod position indication requirements. The rod group alignment limits and the bank insertion limits of LCO 3.1.4, LCO 3.1.5, and LCO 3.1.6 continue to require the rods to be Operable and within the insertion limits.

SR 3.1.4.1 requires verification that the rods are within the alignment limit every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. If a [D]RPI is inoperable, LCO 3.1.7, Conditions A and C, require verification of rod position and under the proposed Required Action A.2.1, this verification may not be performed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Therefore, a Note is proposed to SR 3.1.4.1 to not require performance of the SR for rods associated with an inoperable rod position indicator.

However, LCO 3.1.4 requires rods to be within the alignment limit and is unchanged.

Page 6

TSTF-547, Rev. 1 The TS 3.1.7 Required Actions to determine the position of rods with inoperable [D]RPIs will be used to verify LCO 3.1.4 continues to be met.

3. Allow Time for Thermal Equilibrium of Analog RPI Rod temperature affects the accuracy of the analog RPI system. As a result, analog RPI indications may not be accurate following movement of the associated rod. The proposed change provides a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> period for the drive shaft to reach thermal equilibrium following rod movement to ensure the accuracy of the indication prior to using the analog RPI to verify TS limits.

The proposed change makes the following revisions to the TS:

• SR 3.1.4.1 requires verification that individual rod positions are within the alignment limit. The proposed change adds a Note to the Surveillance which states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after rod motion.]"

• SR 3.1.5.1 requires verification that each shutdown bank is within the insertion limits specified in the COLR. The proposed change adds a Note to the Surveillance which states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]"

• SR 3.1.6.2 requires verification that each control bank is within the insertion limits specified in the COLR. The proposed change adds a Note to the Surveillance which states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]"

• SR 3.1.6.3 requires verification that each control bank that is not fully withdrawn from the core is within the sequence and overlap limits specified in the COLR. The proposed change adds a Note to the Surveillance which states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]"

• LCO 3.1.7 requires the RPI and the Demand Position Indication System to be Operable. The proposed change adds an LCO Note that states that individual RPIs are not required to be Operable for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following movement of the associated rods.

The proposed change is only applicable to analog RPI systems. Plants with analog RPI systems may adopt the bracketed wording. Plants with digital RPI systems omit the bracketed wording. The use of brackets to indicate plant-specific information is a convention in the ISTS.

Technical Evaluation The analog RPI system derives the rod position signal from measurements using a linear variable differential transmitter (LVDT). An analog signal is produced for each rod by the associated LVDT. The rod drive shaft varies the amount of magnetic coupling between the primary and secondary windings of the coils and generates an analog signal proportional to the rod position. As a rod is raised by its magnetic jacks, the magnetic permeability of the rod drive shaft causes an increase in magnetic coupling. Thus, an analog signal that is proportional to the rod position is derived.

Page 7

TSTF-547, Rev. 1 Rod temperature affects the accuracy of the analog RPI System. Due to changes in the magnetic permeability of the drive shaft as a function of its temperature, the indicated position is expected to change with time as the drive shaft temperature changes. As a result, RPI indications may not be accurate following movement of the associated rod.

This occurs most often when the rod movement is associated with a reactor thermal power change. The proposed change provides a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> period for the drive shaft to reach thermal equilibrium following rod movement to ensure accuracy of the indication prior to the RPI being used to verify TS limits. During this period (commonly referred to as a "thermal soak"), the demand rod position is available using the Demand Position Indictor system.

The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> allowance is based on the time necessary to allow the rod drive shaft to reach thermal equilibrium. In the vast majority of cases, the rods are not actually misaligned (only the indication is incorrect) and the risk of an accident occurring during this 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> period is small. During the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> period, the Demand Position Indication system is available to indicate the demand position of the rods. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> allowance has been approved by the NRC for several plants with Westinghouse analog rod position indication systems. For example Salem Units 1 and 2 (Amendment No. 73/48 dated March 19, 1986) and Point Beach Units 1 and 2 (Amendment No. 200/205 dated May 8, 2001.) As stated previously in the discussion of proposed changes, this allowance does not apply to plants with digital RPI systems.

The proposed change to SR 3.1.4.1, SR 3.1.5.1, SR 3.1.6.2, and SR 3.1.6.3 states that the SRs are not required to be performed. These SRs are still required to be met. The difference between "met" and "performed" is explained in Section 1.4 of the TS, which states:

The use of "met" or "performed" in these instances conveys specific meanings. A Surveillance is "met" only when the acceptance criteria are satisfied. Known failure of the requirements of a Surveillance, even without a Surveillance specifically being "performed," constitutes a Surveillance not "met."

"Performance" refers only to the requirement to specifically determine the ability to meet the acceptance criteria.

Therefore, if a rod is known to not meet the SR acceptance criteria, the SR is declared not met even though performance of the SR is not required.

SR 3.1.4.1 requires verification that individual rods are within the alignment limits. The SR is revised to add a Note which states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]" The proposed change provides time for the rod drive shaft to reach thermal equilibrium before performing the SR on the moved rod, in order to ensure the indicated positions are accurate.

SR 3.1.5.1 requires verification that each shutdown bank is within the insertion limits specified in the COLR. The proposed change adds a Note to the Surveillance which states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]" The shutdown banks are not typically moved during power operation, but are required to be Page 8

TSTF-547, Rev. 1 inserted at least 10 steps for performance of SR 3.1.4.2. LCO 3.1.5 contains a Note which exempts the application of the LCO during performance of SR 3.1.4.2. However, following withdrawal of the shutdown rods following performance of SR 3.1.4.2, indicated position may be inaccurate and may incorrectly indicate some rods in the bank are below the insertion limits. As performance of SR 3.1.4.2 will have been completed, the exception Note would no longer apply. Without proposed the SR Note, the LCO may be declared not met when the rods are actually within the insertion limits.

SR 3.1.6.2 requires verification that each control bank is within the insertion limits specified in the COLR. The proposed change adds a Note to the Surveillance which states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]" When the control banks are moved (for example, for performance of SR 3.1.4.2), the indicated position may be inaccurate and may indicate some rods in the bank are below the insertion limits. LCO 3.1.6 contains a Note which exempts the application of the LCO during performance of SR 3.1.4.2. As performance of SR 3.1.4.2 will have been completed, the exception Note would no longer apply. Without proposed the SR Note, the LCO may be declared not met when the rods are actually within the insertion limits.

SR 3.1.6.3 requires verification that each control bank that is not fully withdrawn from the core is within the sequence and overlap limits specified in the COLR. The proposed change adds a Note to the Surveillance which states, "[Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion.]" When the control banks are inserted or withdrawn, the indicated rod positions may not be accurate following movement and may inaccurately indicate that the sequence or overlap limit are not met for some rods.

Without proposed the SR Note, the LCO may be declared not met when the rods are actually within the sequence and overlap limits.

LCO 3.1.4, LCO 3.1.5, and LCO 3.1.6 place requirements on actual rod position.

LCO 3.1.7 requires the RPI system and the Demand Position Indication System to be Operable (i.e., LCO 3.1.7 governs the measurement system and LCO 3.1.4, LCO 3.1.5, and LCO 3.1.6 govern the parameters being measured). LCO 3.1.7 is revised to add an LCO Note that states that individual RPIs are not required to be Operable for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following movement of the associated rods. The LCO Note is required because the analog RPI may not be capable of performing its function during the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following rod movement.

4. Correct Conflicts Between LCO 3.1.4 and LCO 3.1.7 LCO 3.1.4 requires individual indicated rod positions to be within 12 steps of their group step counter demand position, and SR 3.1.4.1 requires verification of the individual rod positions within the alignment limit (i.e., the demand bank position) every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. If a bank demand position indication is inoperable, SR 3.1.4.1 cannot be performed and the TS 3.1.4 Action for more than one rod not within the alignment limit applies, which requires the plant to be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. However, TS 3.1.7, which requires the bank demand position indication to be Operable, allows continued full power operation with one or more demand position indicators inoperable if compensatory Required Actions are taken. These compensatory Required Actions are to verify the [D]RPIs Page 9

TSTF-547, Rev. 1 associated with the affected banks are Operable and the associated rod are 12 steps apart. This satisfies the intent of SR 3.1.4.1. To correct this conflict, a Note is added to SR 3.1.4.1 which states that the SR is not required to be performed for rods associated with an inoperable demand position indicator. The Note is an exception to performing the SR, but not to meeting the SR. The TS 3.1.7 Required Actions verify that the acceptance criteria of SR 3.1.4.1 continue to be met.

Similarly, SR 3.1.7.1 requires verification that each [D]RPI agrees within [12] steps of the group demand position for the [full indicated range] of rod travel. The SR is performed prior to reactor criticality after each removal of the reactor head. However, SR 3.0.1 states that SRs must be met between performances. Therefore, if a control or shutdown rod is not within [12] steps of the group demand position, LCO 3.1.4 is not met and LCO 3.1.7 is not met. TS 3.1.4, Condition B, allows continued plant operation at reduced power, but there is no applicable Condition in TS 3.1.7. The TS 3.1.7 Actions only apply to inoperable [D]RPIs and demand position indicators, and in this situation both are Operable and accurately reflecting the actual position of the rod. With no applicable Condition in TS 3.1.7, LCO 3.0.3 requires a plant shutdown. To address this conflict, a Note is proposed to be added to SR 3.1.7.1 which states that the SR is not required to be met for rods known not to meet LCO 3.1.4.

Technical Evaluation The Actions of TS 3.1.4 are intended to address misaligned or inoperable rods. The Actions of TS 3.1.7 are intended to address inoperable [D]RPIs or inoperable demand position indicators. SR 3.0.1 states that SRs do not have to be performed on inoperable equipment, but in the cited situations, the equipment described in the associated LCO is Operable so the exception does not apply.

The proposed change clarifies the intent of TS 3.1.4 and TS 3.1.7 by ensuring that the appropriate Actions are followed when equipment is inoperable and eliminates unintended conflicts between the two specifications.

5. Eliminate an Unnecessary Action from TS 3.1.7 TS 3.1.7, Condition B, applies when more than one [D]RPI is inoperable per bank in one or more banks. Required Action B.2 states, "Monitor and record Reactor Coolant System Tavg."

The Bases of Required Action B.2 states:

"Monitoring and recording reactor coolant Tavg helps assure that significant changes in power distribution and SDM are avoided. The once per hour Completion Time is acceptable because only minor fluctuations in RCS temperature are expected at steady state plant operating conditions."

Required Action B.2 imposes an administrative burden with no safety benefit because there are no acceptance criteria associated with the Tavg values that are recorded and there are no actions associated with any trends identified. Monitoring Tavg provides no power Page 10

TSTF-547, Rev. 1 distribution information for unmonitored rods that isn't better provided by the existing requirements in Condition A and average coolant temperature provides no indication of changes in SDM. Therefore, the proposed Required Action is proposed to be deleted.

6. Other Proposed Changes The following changes are made to improve the presentation of the requirements:

a. LCO 3.1.4, Condition B, is revised to eliminate Required Action B.1 and to combine Required Actions B.2.4 and B.2.5. Condition B applies when one rod is not within the alignment limits and Required Action B.1 requires restoring the rod to within limits within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The Writer's Guide (Ref. 1), Section 4.1.6.g, states:

"A Required Action which requires restoration, such that the Condition is no longer met, is considered superfluous. It is only included if it would be the only Required Action for the Condition or it is needed for presentation clarity."

Required Action B.1 is an action that requires restoration and is not the only Required Action. Further, elimination of the unnecessary Required Action B.1 simplifies the Required Actions by eliminating a level of indenting (e.g., B.2.3 becomes B.3). Therefore, the Required Action is eliminated. Similarly, both Required Action B.2.4 and B.2.5 require performing Surveillances every 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Combining the Required Actions simplifies the presentation.

b. LCO 3.1.5 and LCO 3.1.6 contain a Note modifying the Applicability that states, "This LCO is not applicable while performing SR 3.1.4.2." The proposed change moves the LCO 3.1.5 and LCO 3.1.6 Applicability Notes to LCO Notes and revises the Notes to state, "Not applicable to shutdown banks inserted while performing SR 3.1.4.2" for LCO 3.1.5 and "Not applicable to control banks inserted while performing SR 3.1.4.2" for LCO 3.1.6. The current Note is improperly placed and worded.

The existing Note is not an exception to the Applicability of Modes 1 and 2. The allowance is an exception to the LCO. Further, the wording, "This LCO is not applicable while performing SR 3.1.4.2," is in direct conflict with the Writer's Guide (Ref. 1), Section 4.1.4.d, which states:

"Notes associated with the LCO will always follow the LCO. LCO Notes may allow a limited exception to the LCO requirement stated above the Note. Their use should be minimized. It is inherently understood what requirement the Note is referring to, based on the format used. It is therefore not appropriate to add clarifying clauses such as 'For this LCO..'." (emphasis added)

The proposed change does not alter the intent or application of the exception, while correcting an error in the placement and wording of the Notes.

Page 11

TSTF-547, Rev. 1

c. Specification 3.1.7 is revised to consistently use the defined abbreviation

"[D]RPI." This affects the Actions Note, Required Action A.1, Required Action B.2, and Required Action C.1.

d. TS 3.1.7, Condition A is revised from "for one or more groups" to the more standard terminology "in one or more groups," and TS 3.1.7, Condition B is revised to include the phrase "in one or more groups" to be more consistent with the wording of Condition A.

The existing Condition A states, "One [D]RPI per group inoperable for one or more groups." As an editorial improvement, Condition A is revised from "for one or more groups" to the more standard "in one or more groups." The existing Condition B states, "More than one [D]RPI per group inoperable." Condition B is revised to include the phrase "in one or more groups." This is a clarification to improve consistency with the existing Condition A and does not change the intent of Condition B, but increases consistency in the presentation.

e. TS 3.1.7, Required Action B.3 is redundant to Required Action A.1. This Required Action is proposed to be deleted. Condition A applies when one [D]RPI per group is inoperable and Condition B applies when more than one [D]RPI per group is inoperable. The Actions are modified by a separate condition entry Note.

Therefore, under the TS usage rules, every entry into Condition B is accompanied by separate entry into Condition A for the inoperable [D]RPI. Both Condition A and Condition B contain a Required Action (A.1 and B.3) to verify the position of the rods with inoperable [D]RPI indirectly by using the movable incore detectors.

Therefore, Required Action B.3, is redundant and unnecessary because Required Action A.1 is always applicable. Therefore, Required Action B.3 is proposed to be eliminated. This change has no effect on the actions performed when a [D]RPI is inoperable and improves the presentation of the requirements.

f. TS 3.1.7, Condition C is inconsistently worded and is revised without changing the intent. The existing Condition C states, "One or more rods with inoperable position indicators have been moved > 24 steps in one direction since the last determination of the rod's position." This Condition is poorly worded and inconsistent with Conditions A and B, which start the Condition describing the inoperable equipment (e.g., "One [D]RPI per group inoperable..."). The proposed change rewords the Condition to state, "One or more [D]RPI inoperable in one or more groups and associated rods have been moved > 24 steps in one direction since the last position determination." The proposed change does not change the intent and makes the Conditions more consistent.

g. TS 3.1.7, Condition D is revised to be consistent with the existing separate Condition entry note without changing the intent. It is proposed to state, "One or more demand position indicators per bank inoperable in one or more banks."

The proposed change revises Condition D from "One demand position indicator per bank inoperable for one or more banks" to "One or more demand position Page 12

TSTF-547, Rev. 1 indicators per bank inoperable in one or more banks." The proposed change makes the Condition wording consistent with the separate Condition entry Note modifying the Actions and does not alter the intent of Condition D. The current TS 3.1.7 is modified by an ACTIONS Note which states, "Separate Condition entry is allowed for each inoperable rod position indicator and each demand position indicator." The Bases for the Note state that the Note is acceptable because the Required Actions for each Condition provide appropriate compensatory actions for each inoperable indicator. LCO 3.1.7, Condition D, states "One demand position indicator per bank inoperable for one or more banks." There is one demand position indicator per group of rods, two demand indicators per bank in those banks with two groups. The separate Condition entry Note modifying the 3.1.7 ACTIONS clearly states that separate Condition entry is allowed for inoperable demand position indicators which means that the Condition D is applicable to more than one inoperable demand position indicator per bank. However, the existing Condition D wording is inconsistent with the separate Condition entry Note and could lead to the misapplication of the TS.

The proposed change does not alter the intent of the TS, but eliminates a potential misinterpretation that could lead to an unnecessary plant shutdown.

The Required Actions of Condition D provide appropriate compensatory measures for one or more inoperable demand position indicator. Required Action D.1.1 requires administrative verification that the [D]RPIs for the affected banks are Operable, thus providing indication of the rod position. Required Action D.1.2 also requires periodic verification that the most withdrawn and least withdrawn rods in the affected banks are within 12 steps apart. If these Actions cannot be performed, power is reduced to < 50% RTP. Without the proposed clarification to Condition D, and despite the separate Condition entry Note, it could be construed that Condition D cannot be entered for two demand position indicators in the same bank inoperable. Under this misinterpretation, two inoperable demand position indicators in the same bank would lead to an LCO 3.0.3 entry. This is inappropriate and is not what is intended under the separate Condition entry Note. The Required Actions provided in Condition D are equally applicable to two inoperable demand position indicators in a bank as to two inoperable demand position indicators in separate banks.

Technical Evaluation The other proposed changes affect only the presentation without changing the intent. As the changes are not technical in nature, no additional technical evaluation is provided.

4. REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria The following lists the regulatory requirements and plant-specific design bases related to the proposed change.

Page 13

TSTF-547, Rev. 1 10 CFR 50, Appendix A, General Design Criteria (GDC) 13 specifies that instrumentation shall be provided to monitor variables and systems over their operating ranges during normal operation, anticipated operational occurrences, and accident conditions. LCO 3.1.7 requires Operability of the [D]RPI system and the bank demand position indication system, to allow verification of compliance with the rod alignment and insertion limits.

10 CFR 50, Appendix A, GDC 26, "Reactivity control system redundancy and capability," states that control rods, preferably including a positive means for inserting the rods, shall be capable of reliably controlling reactivity changes to assure that under conditions of normal operation, including anticipated operational occurrences, and with appropriate margin for malfunctions such as stuck rods, specified acceptable fuel design limits are not exceeded.

10 CFR 50, Appendix A, GDC 28, "Reactivity Limits," states that the reactivity control systems shall be designed with appropriate limits on the potential amount and rate of reactivity increase to assure that the effects of postulated reactivity accidents can neither (1) result in damage to the reactor coolant pressure boundary greater than limited local yielding nor (2) sufficiently disturb the core, its support structures or other reactor pressure vessel internals to impair significantly the capability to cool the core.

Limits on control and shutdown rod insertion have been established, and all rod positions are monitored and controlled during power operation to ensure that the power distribution and reactivity limits defined by the design power peaking and SDM limits are preserved.

The proposed change does not affect the ability to satisfy these design criteria.

4.2 No Significant Hazards Consideration Determination The proposed change revises the requirements on control and shutdown rods, and rod and bank position indication to allow time for analog position indication instruments to read accurately after rod movement, to provide time to correct rod control system failures that do not affect Operability, to correct the rod position indication Technical Specifications (TS) to be internally consistent and eliminate actions that provide no safety benefit, to correct a conflict between the requirements of LCO 3.1.4 and LCO 3.1.7, and to provide an alternative to frequent use of the movable incore detector system.

The TSTF has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, Issuance of Amendment:

1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No Control and shutdown rods are assumed to insert into the core to shut down the reactor in evaluated accidents. Rod insertion limits ensure that adequate negative Page 14

TSTF-547, Rev. 1 reactivity is available to provide the assumed shutdown margin (SDM). Rod alignment and overlap limits maintain an appropriate power distribution and reactivity insertion profile.

Control and shutdown rods are initiators to several accidents previously evaluated, such as rod ejection. The proposed change does not change the limiting conditions for operation for the rods or make any technical changes to the Surveillance Requirements (SRs) governing the rods. Therefore, the proposed change has no significant effect on the probability of any accident previously evaluated.

Revising the TS Actions to provide a limited time to repair rod control system failures has no effect on the SDM assumed in the accident analysis as the proposed Action require verification that SDM is maintained. The effects on power distribution will not cause a significant increase in the consequences of any accident previously evaluated as all TS requirements on power distribution continue to be applicable.

Revising the TS Actions to provide an alternative to frequent use of the moveable incore detector system to verify the position of rods with inoperable rod position indicator does not change the requirement for the rods to be aligned and within the insertion limits. Therefore, the assumptions used in any accidents previously evaluated are unchanged and there is no significant increase in the consequences.

The consequences of an accident that might occur during the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> period provided for the analog rod position indication to stabilize after rod movement are no different than the consequences of the accident under the existing actions with the rod declared inoperable.

The proposed change to resolve the conflicts in the TS ensure that the intended Actions are followed when equipment is inoperable. Actions taken with inoperable equipment are not assumptions in the accidents previously evaluated and have no significant effect on the consequences.

The proposed change to eliminate an unnecessary action has no effect on the consequences of accidents previously evaluated as the analysis of those accidents did not consider the use of the action.

The proposed change to increase consistency within the TS has no effect on the consequences of accidents previously evaluated as the proposed change clarifies the application of the existing requirements and does not change the intent.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

Page 15

TSTF-547, Rev. 1

2. Does the proposed amendment create the possibility of a new or different kind of accident from any previously evaluated?

Response: No The proposed change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed).. The change does not alter assumptions made in the safety analyses. The proposed change does not alter the limiting conditions for operation for the rods or make any technical changes to the SRs governing the rods. The proposed change to actions maintains or improves safety when equipment is inoperable and does not introduce new failure modes.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3. Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No The proposed change to allow time for rod position indication to stabilize after rod movement and to allow an alternative method of verifying rod position has no effect on the safety margin as actual rod position is not affected. The proposed change to provide time to repair rods that are Operable but immovable does not result in a significant reduction in the margin of safety because all rods must be verified to be Operable, and all other banks must be within the insertion limits.

The remaining proposed changes to make the requirements internally consistent and to eliminate unnecessary actions do not affect the margin of safety as the changes do not affect the ability of the rods to perform their specified safety function.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, the TSTF concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

4.3 Conclusions In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Page 16

TSTF-547, Rev. 1

5. ENVIRONMENTAL CONSIDERATION Evaluation of the proposed change has determined that the change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in the individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), an environmental assessment of the proposed change is not required.

6. REFERENCES

1. TSTF-GG-05-01, "Writers Guide for Plant-Specific Improved Technical Specifications, TSTF-GG-05-01," Revision 1, August 2010.

Page 17

TSTF-547, Rev. 1 Attachment 1 Model Application

TSTF-547, Rev. 1

[DATE] 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

PLANT NAME DOCKET NO. 50-[xxx]

APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT TSTF-547, "CLARIFICATION OF ROD POSITION REQUIREMENTS"

Dear Sir or Madam:

Pursuant to 10 CFR 50.90, [LICENSEE] is submitting a request for an amendment to the Technical Specifications (TS) for [PLANT NAME, UNIT NOS.].

The proposed amendment revises the requirements on control and shutdown rods, and rod and bank position indication. Attachment 1 provides a description and assessment of the proposed changes. Attachment 2 provides the existing TS pages marked up to show the proposed changes. provides revised (clean) TS pages. Attachment 4 provides existing TS Bases pages marked to show the proposed changes for information only.

Approval of the proposed amendment is requested by [date]. Once approved, the amendment shall be implemented within [ ] days.

In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the designated [STATE] Official.

Page 19

TSTF-547, Rev. 1

[In accordance with 10 CFR 50.30(b), a license amendment request must be executed in a signed original under oath or affirmation. This can be accomplished by attaching a notarized affidavit confirming the signature authority of the signatory, or by including the following statement in the cover letter: "I declare under penalty of perjury that the foregoing is true and correct.

Executed on (date)." The alternative statement is pursuant to 28 USC 1746. It does not require notarization.]

If you should have any questions regarding this submittal, please contact [NAME, TELEPHONE NUMBER].

Sincerely,

[Name, Title]

Attachments: 1. Description and Assessment

2. Proposed Technical Specification Changes (Mark-Up)

3. Revised Technical Specification Pages

4. Proposed Technical Specification Bases Changes (Mark-Up) cc: NRC Project Manager NRC Regional Office NRC Resident Inspector State Contact Page 20

TSTF-547, Rev. 1 ATTACHMENT 1 - DESCRIPTION AND ASSESSMENT

1.0 DESCRIPTION

The proposed amendment revises the requirements on control and shutdown rods, and rod and bank position indication in Technical Specification (TS) 3.1.4, "Rod Group Alignment Limits,"

TS 3.1.5, "Shutdown Bank Insertion Limits," TS 3.1.6, "Control Bank Insertion Limits," and TS 3.1.7, "Rod Position Indication," [to provide time to repair rod movement failures that do not affect rod Operability, to provide an alternative to frequent use of the movable incore detector system when position indication for a rod is inoperable, to provide time for analog position indication instruments to read accurately after rod movement, to correct conflicts between the TS, to eliminate an unnecessary action, and to increase consistency and to improve the presentation.]

2.0 ASSESSMENT 2.1 Applicability of Safety Evaluation

[LICENSEE] has reviewed the safety evaluation for TSTF-547 provided to the Technical Specifications Task Force in a letter dated [DATE]. This review included a review of the NRC staffs evaluation, as well as the information provided in TSTF-547. [As described in the subsequent paragraphs,] [LICENSEE] has concluded that the justifications presented in the TSTF-547 proposal and the safety evaluation prepared by the NRC staff are applicable to

[PLANT, UNIT NOS.] and justify this amendment for the incorporation of the changes to the

[PLANT] TS.

2.2 Variations

[LICENSEE is not proposing any variations from the TS changes described in the TSTF-547 or the applicable parts of the NRC staffs safety evaluation dated [DATE].] [LICENSEE is proposing the following variations from the TS changes described in the TSTF-547 or the applicable parts of the NRC staffs safety evaluation dated [DATE]. These variations do not affect the applicability of TSTF-547 or the NRC staff's safety evaluation to the proposed license amendment.]

[The [PLANT] TS utilize different [numbering] [and titles] than the Standard Technical Specifications on which TSTF-547 was based. Specifically, [describe differences between the plant-specific TS numbering and/or titles and the TSTF-547 numbering and titles.] These differences are administrative and do not affect the applicability of TSTF-547 to the [PLANT]

TS.]

[The Traveler and safety evaluation discuss the applicable regulatory requirements and guidance, including the 10 CFR 50, Appendix A, General Design Criteria (GDC). [PLANT] was not licensed to the 10 CFR 50, Appendix A, GDC. The [PLANT] equivalent of the referenced GDC are [REFERENCE INCLUDING UFSAR LOCATION, IF APPLICABLE]. [DISCUSS THE EQUIVALENCE OF THE REFERENCED PLANT-SPECIFIC REQUIREMENTS TO THE Page 21

TSTF-547, Rev. 1 APPENDIX A GDC AS RELATED TO THE PROPOSED CHANGE.] This difference does not alter the conclusion that the proposed change is applicable to [PLANT].]

3.0 REGULATORY ANALYSIS

3.1 No Significant Hazards Consideration Analysis

[LICENSEE] requests adoption of TSTF-547, "Clarification of Rod Position Requirements,"

which is an approved change to the Standard Technical Specifications, into the [PLANT NAME, UNIT NOS] Technical Specifications (TS). The proposed change revises the requirements on control and shutdown rods, and rod and bank position indication to provide time to repair rod movement failures that do not affect rod Operability, to provide an alternative to frequent use of the movable incore detector system when position indication for a rod is inoperable, to provide time for analog position indication instruments to read accurately after rod movement, to correct conflicts between the TS, to eliminate an unnecessary action, and to increase consistency and to improve the presentation.

[LICENSEE] has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No Control and shutdown rods are assumed to insert into the core to shut down the reactor in evaluated accidents. Rod insertion limits ensure that adequate negative reactivity is available to provide the assumed shutdown margin (SDM). Rod alignment and overlap limits maintain an appropriate power distribution and reactivity insertion profile.

Control and shutdown rods are initiators to several accidents previously evaluated, such as rod ejection. The proposed change does not change the limiting conditions for operation for the rods or make any technical changes to the Surveillance Requirements (SRs) governing the rods. Therefore, the proposed change has no significant effect on the probability of any accident previously evaluated.

Revising the TS Actions to provide a limited time to repair rod movement control has no effect on the SDM assumed in the accident analysis as the proposed Action require verification that SDM is maintained. The effects on power distribution will not cause a significant increase in the consequences of any accident previously evaluated as all TS requirements on power distribution continue to be applicable.

Revising the TS Actions to provide an alternative to frequent use of the moveable incore detector system to verify the position of rods with inoperable rod position indicator does not change the requirement for the rods to be aligned and within the insertion limits.

Page 22

TSTF-547, Rev. 1 Therefore, the assumptions used in any accidents previously evaluated are unchanged and there is no significant increase in the consequences.

The consequences of an accident that might occur during the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> period provided for the analog rod position indication to stabilize after rod movement are no different than the consequences of the accident under the existing actions with the rod declared inoperable.

The proposed change to resolve the conflicts in the TS ensure that the intended Actions are followed when equipment is inoperable. Actions taken with inoperable equipment are not assumptions in the accidents previously evaluated and have no significant effect on the consequences.

The proposed change to eliminate an unnecessary action has no effect on the consequences of accidents previously evaluated as the analysis of those accidents did not consider the use of the action.

The proposed change to increase consistency within the TS has no effect on the consequences of accidents previously evaluated as the proposed change clarifies the application of the existing requirements and does not change the intent.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed amendment create the possibility of a new or different kind of accident from any previously evaluated?

Response: No The proposed change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed).. The change does not alter assumptions made in the safety analyses. The proposed change does not alter the limiting conditions for operation for the rods or make any technical changes to the SRs governing the rods.

The proposed change to actions maintains or improves safety when equipment is inoperable and does not introduce new failure modes.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3. Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No The proposed change to allow time for rod position indication to stabilize after rod movement and to allow an alternative method of verifying rod position has no effect on the safety margin as actual rod position is not affected. The proposed change to provide time to repair rods that are Operable but immovable does not result in a significant reduction in the margin of safety because all rods must be verified to be Operable, and all Page 23

TSTF-547, Rev. 1 other banks must be within the insertion limits. The remaining proposed changes to make the requirements internally consistent and to eliminate unnecessary actions do not affect the margin of safety as the changes do not affect the ability of the rods to perform their specified safety function.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, [LICENSEE] concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

3.2 Conclusions In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

4.0 ENVIRONMENTAL EVALUATION The proposed change would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed change.

{Note: Attachments 2, 3, and 4 are not included in the model application and will be provided by the licensee.}

Page 24

TSTF-547, Rev. 1 Rod Group Alignment Limits 3.1.4 3.1 REACTIVITY CONTROL SYSTEMS 3.1.4 Rod Group Alignment Limits LCO 3.1.4 All shutdown and control rods shall be OPERABLE.

AND Individual indicated rod positions shall be within 12 steps of their group step counter demand position.

APPLICABILITY: MODES 1 and 2.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or more rod(s) A.1.1 Verify SDM to be within the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> inoperable. limits specified in the COLR.

OR A.1.2 Initiate boration to restore 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> SDM to within limit.

AND A.2 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> B. One rod not within B.1 Restore rod to within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> alignment limits. alignment limits.

OR B.2.1.1 Verify SDM to be within the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> limits specified in the COLR.

OR Westinghouse STS 3.1.4-1 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits 3.1.4 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B.2.1.2 Initiate boration to restore 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> SDM to within limit.

AND B.2.2 Reduce THERMAL 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> POWER to 75% RTP.

AND B.2.3 Verify SDM is within the Once per limits specified in the 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> COLR.

AND B.2.4 Perform SR 3.2.1.1, and 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> SR 3.2.1.2, and SR 3.2.2.1.

AND B.2.5 Perform SR 3.2.2.1. 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AND B.2.65 Re-evaluate safety 5 days analyses and confirm results remain valid for duration of operation under these conditions.

C. Required Action and C.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time of Condition B not met.

D. More than one rod not D.1.1 Verify SDM is within the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> within alignment limit. limits specified in the COLR.

OR Westinghouse STS 3.1.4-2 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits 3.1.4 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D.1.2 Initiate boration to restore 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> required SDM to within limit.

AND D.2 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.1.4.1 -------------------- NOTES---------------------------------- [ 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />

1. Not required to be performed for rods associated with inoperable rod position indicator or demand OR position indicator.

In accordance

[2. Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after with the associated rod motion.] Surveillance

---

Frequency Control Program ]

Verify position of individual rods positions within alignment limit.

SR 3.1.4.2 Verify rod freedom of movement (trippability) by [ 92 days moving each rod not fully inserted in the core 10 steps in either direction. OR In accordance with the Surveillance Frequency Control Program ]

Westinghouse STS 3.1.4-3 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits 3.1.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.1.4.3 Verify rod drop time of each rod, from the fully Prior to criticality withdrawn position, is [2.2] seconds from the after each beginning of decay of stationary gripper coil voltage removal of the to dashpot entry, with: reactor head

a. Tavg 500°F and

b. All reactor coolant pumps operating.

Westinghouse STS 3.1.4-4 Rev. 4.0

TSTF-547, Rev. 1 Shutdown Bank Insertion Limits 3.1.5 3.1 REACTIVITY CONTROL SYSTEMS 3.1.5 Shutdown Bank Insertion Limits LCO 3.1.5 Each shutdown bank shall be within insertion limits specified in the COLR.

---

NOTE-----------------------------------------------

Not applicable to shutdown banks inserted while performing SR 3.1.4.2.

APPLICABILITY: MODES 1 and 2.

---

NOTE-----------------------------------------------

This LCO is not applicable while performing SR 3.1.4.2.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One shutdown bank A.1 Verify all control banks are 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> inserted [16] steps within the insertion limits beyond the insertion specified in the COLR.

limits specified in the COLR. AND A.2.1 Verify SDM is within the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> limits specified in the COLR.

OR A.2.2 Initiate boration to restore 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> SDM to within limit.

AND A.3 Restore the shutdown bank 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to within the insertion limits specified in the COLR.

BA. One or more shutdown BA.1.1 Verify SDM is within the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> banks not within limits limits specified in the for reasons other than COLR.

Condition A.

OR Westinghouse STS 3.1.5-1 Rev. 4.0

TSTF-547, Rev. 1 Shutdown Bank Insertion Limits 3.1.5 CONDITION REQUIRED ACTION COMPLETION TIME BA.1.2 Initiate boration to restore 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> SDM to within limit.

AND AB.2 Restore shutdown banks to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> within limits.

CB. Required Action and CB.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not met.

Westinghouse STS 3.1.5-2 Rev. 4.0

TSTF-547, Rev. 1 Shutdown Bank Insertion Limits 3.1.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.1.5.1 [---------------------------- NOTE ------------------------------ [ 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion. OR

---

]

In accordance Verify each shutdown bank is within the insertion with the limits specified in the COLR. Surveillance Frequency Control Program ]

Westinghouse STS 3.1.5-3 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits 3.1.6 3.1 REACTIVITY CONTROL SYSTEMS 3.1.6 Control Bank Insertion Limits LCO 3.1.6 Control banks shall be within the insertion, sequence, and overlap limits specified in the COLR.

---

NOTE-----------------------------------------------

Not applicable to control banks inserted while performing SR 3.1.4.2.

APPLICABILITY: MODE 1, MODE 2 with keff 1.0.

---

NOTE----------------------------------------------

This LCO is not applicable while performing SR 3.1.4.2.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Control bank A, B, or C A.1 Verify all shutdown banks 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> inserted [16] steps are within the insertion beyond the insertion, limits specified in the sequence, or overlap COLR.

limits specified in the COLR. AND A.2.1 Verify SDM is within the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> limits specified in the COLR.

OR A.2.2 Initiate boration to restore 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> SDM to within limit.

AND A.3 Restore the control bank to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> within the insertion, sequence, and limits specified in the COLR.

BA. Control bank BA.1.1 Verify SDM is within the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> insertion limits not met limits specified in the Westinghouse STS 3.1.6-1 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits 3.1.6 CONDITION REQUIRED ACTION COMPLETION TIME for reasons other than COLR.

Condition A.

OR BA.1.2 Initiate boration to restore 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> SDM to within limit.

AND BA.2 Restore control bank(s) to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> within limits.

CB. Control bank sequence CB.1.1 Verify SDM is within the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or overlap limits not met limits specified in the for reasons other than COLR.

Condition A.

OR CB.1.2 Initiate boration to restore 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> SDM to within limit.

AND Westinghouse STS 3.1.6-2 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits 3.1.6 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME CB.2 Restore control bank 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> sequence and overlap to within limits.

DC. Required Action and DC.1 Be in MODE 2 with keff 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion < 1.0.

Time not met.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.1.6.1 Verify estimated critical control bank position is Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> within the limits specified in the COLR. prior to achieving criticality SR 3.1.6.2 [---------------------------- NOTE ------------------------------ [ 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion. OR

---

]

In accordance Verify each control bank insertion is within the with the insertion limits specified in the COLR. Surveillance Frequency Control Program ]

SR 3.1.6.3 [---------------------------- NOTE ------------------------------ [ 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion. OR

---

]

In accordance Verify sequence and overlap limits specified in the with the COLR are met for control banks not fully withdrawn Surveillance from the core. Frequency Control Program ]

Westinghouse STS 3.1.6-3 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication 3.1.7 3.1 REACTIVITY CONTROL SYSTEMS 3.1.7 Rod Position Indication LCO 3.1.7 The [Digital] Rod Position Indication ([D]RPI) System and the Demand Position Indication System shall be OPERABLE.

---

NOTE ---------------------------------------------------

[Individual RPIs are not required to be OPERABLE for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following movement of the associated rods.]

APPLICABILITY: MODES 1 and 2.

ACTIONS

---

NOTE-----------------------------------------------------------

Separate Condition entry is allowed for each inoperable [D]RPI rod position indicator and each demand position indicator.

CONDITION REQUIRED ACTION COMPLETION TIME A. One [D]RPI per group A.1 Verify the position of the Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> inoperable infor one or rods with inoperable [D]RPI more groups. position indicators indirectly by using movable incore detectors.

OR A.2.1 Verify the position of the 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> rods with inoperable [D]RPI indirectly by using the AND moveable incore detectors.

Once per 31 EFPD thereafter AND AND 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after discovery of each unintended rod movement AND Westinghouse STS 3.1.7-1 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication 3.1.7 CONDITION REQUIRED ACTION COMPLETION TIME 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after each movement of rod with inoperable [D]RPI

> 12 steps AND Prior to THERMAL POWER exceeding 50% RTP AND 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after reaching RTP A.2.2 Restore inoperable [D]RPI Prior to entering to OPERABLE status. MODE 2 from MODE 3 OR A.32 Reduce THERMAL 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> POWER to 50% RTP.

B. More than one [D]RPI B.1 Place the control rods Immediately per group inoperable in under manual control.

one or more groups.

AND B.2 Monitor and record Reactor Once per 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Coolant System Tavg.

AND Westinghouse STS 3.1.7-2 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication 3.1.7 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B.3 Verify the position of the Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> rods with inoperable position indicators indirectly by using the movable incore detectors.

AND B.24 Restore inoperable [D]RPIs 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> position indicators to OPERABLE status such that a maximum of one

[D]RPI per group is inoperable.

C. One or more [D]RPI C.1 Verify the position of the [4] hours inoperable in one or rods with inoperable more groups and [D]RPIs position indicators associated rod has One indirectly by using movable or more rods with incore detectors.

inoperable position indicators have been OR moved > in excess of 24 steps in one C.2 Reduce THERMAL 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> direction since the last POWER to 50% RTP.

determination of the rod's position.

D. One or more demand D.1.1 Verify by administrative Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> position indicators per means all [D]RPIs for the bank inoperable for in affected banks are one or more banks. OPERABLE.

AND D.1.2 Verify the most withdrawn Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> rod and the least withdrawn rod of the affected banks are 12 steps apart.

OR Westinghouse STS 3.1.7-3 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication 3.1.7 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D.2 Reduce THERMAL 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> POWER to 50% RTP.

E. Required Action and E.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not met.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.1.7.1 -------------------- NOTE----------------------------------- Once prior to Not required to be met for [D]RPIs associated with criticality after rods that do not meet LCO 3.1.4. each removal of

---

the reactor head Verify each [D]RPI agrees within [12] steps of the group demand position for the [full indicated range]

of rod travel.

Westinghouse STS 3.1.7-4 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 B 3.3 INSTRUMENTATION B 3.1.4 Rod Group Alignment Limits BASES BACKGROUND The OPERABILITY (i.e., trippability) of the shutdown and control rods is an initial assumption in all safety analyses that assume rod insertion upon reactor trip. Maximum rod misalignment is an initial assumption in the safety analysis that directly affects core power distributions and assumptions of available SDM.

The applicable criteria for these reactivity and power distribution design requirements are 10 CFR 50, Appendix A, GDC 10, "Reactor Design,"

GDC 26, "Reactivity Control System Redundancy and Capability" (Ref. 1),

and 10 CFR 50.46, "Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Plants" (Ref. 2).

Mechanical or electrical failures may cause a control or shutdown rod to become inoperable or to become misaligned from its group. Rod inoperability or misalignment may cause increased power peaking, due to the asymmetric reactivity distribution and a reduction in the total available rod worth for reactor shutdown. Therefore, rod alignment and OPERABILITY are related to core operation in design power peaking limits and the core design requirement of a minimum SDM.

Limits on rod alignment have been established, and all rod positions are monitored and controlled during power operation to ensure that the power distribution and reactivity limits defined by the design power peaking and SDM limits are preserved.

Rod cluster control assemblies (RCCAs), or rods, are moved by their control rod drive mechanisms (CRDMs). Each CRDM moves its RCCA one step (approximately e inch) at a time, but at varying rates (steps per minute) depending on the signal output from the Rod Control System.

The RCCAs are divided among control banks and shutdown banks. Each bank may be further subdivided into two groups to provide for precise reactivity control. A group consists of two or more RCCAs that are electrically paralleled to step simultaneously. If a bank of RCCAs consists of two groups, the groups are moved in a staggered fashion, but always within one step of each other. All units have four control banks and at least two shutdown banks.

The shutdown banks are maintained either in the fully inserted or fully withdrawn position. The control banks are moved in an overlap pattern, using the following withdrawal sequence: When control bank A reaches a predetermined height in the core, control bank B begins to move out with Westinghouse STS B 3.1.4-1 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 BASES BACKGROUND (continued) control bank A. Control bank A stops at the position of maximum withdrawal, and control bank B continues to move out. When control bank B reaches a predetermined height, control bank C begins to move out with control bank B. This sequence continues until control banks A, B, and C are at the fully withdrawn position, and control bank D is approximately halfway withdrawn. The insertion sequence is the opposite of the withdrawal sequence. The control rods are arranged in a radially symmetric pattern, so that control bank motion does not introduce radial asymmetries in the core power distributions.

The axial position of shutdown rods and control rods is indicated by two separate and independent systems, which are the Bank Demand Position Indication System (commonly called group step counters) and the Digital Rod Position Indication (DRPI) System.

The Bank Demand Position Indication System counts the pulses from the rod control system that moves the rods. There is one step counter for each group of rods. Individual rods 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 Bank Demand Position Indication System is considered highly precise (+/- 1 step or +/- e inch). If a rod does not move one step for each demand pulse, the step counter will still count the pulse and incorrectly reflect the position of the rod.

The DRPI System provides a highly accurate indication of actual rod position, but at a lower precision than the step counters. This system is based on inductive analog signals from a series of coils spaced along a hollow tube. To increase the reliability of the system, the inductive coils are connected alternately to data system A or B. Thus, if one data system fails, the DRPI will go on half accuracy. The DRPI System is capable of monitoring rod position within at least +/- 12 steps with either full accuracy or half accuracy.

APPLICABLE Control rod misalignment accidents are analyzed in the safety analysis SAFETY (Ref. 3). The acceptance criteria for addressing control rod inoperability ANALYSES or misalignment are that:

a. There be no violations of:

1. Specified acceptable fuel design limits or

2. Reactor Coolant System (RCS) pressure boundary integrity and

b. The core remains subcritical after accident transients.

Westinghouse STS B 3.1.4-2 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 BASES APPLICABLE SAFETY ANALYSES (continued)

Two types of misalignment are distinguished. During movement of a control rod group, one rod may stop moving, while the other rods in the group continue. This condition may cause excessive power peaking.

The second type of misalignment occurs if one rod fails to insert upon a reactor trip and remains stuck fully withdrawn. This condition requires an evaluation to determine that sufficient reactivity worth is held in the control rods to meet the SDM requirement, with the maximum worth rod stuck fully withdrawn.

Two types of analysis are performed in regard to static rod misalignment (Ref. 4). With control banks at their insertion limits, one type of analysis considers the case when any one rod is completely inserted into the core.

The second type of analysis considers the case of a completely withdrawn single rod from a bank inserted to its insertion limit. Satisfying limits on departure from nucleate boiling ratio in both of these cases bounds the situation when a rod is misaligned from its group by 12 steps.

Another type of misalignment occurs if one RCCA fails to insert upon a reactor trip and remains stuck fully withdrawn. This condition is assumed in the evaluation to determine that the required SDM is met with the maximum worth RCCA also fully withdrawn (Ref. 5).

The Required Actions in this LCO ensure that either deviations from the alignment limits will be corrected or that THERMAL POWER will be adjusted so that excessive local linear heat rates (LHRs) will not occur, and that the requirements on SDM and ejected rod worth are preserved.

Continued operation of the reactor with a misaligned control rod is allowed if the heat flux hot channel factor ( FQ(Z)) and the nuclear enthalpy hot channel factor ( F N H ) are verified to be within their limits in the COLR and the safety analysis is verified to remain valid. When a control rod is misaligned, the assumptions that are used to determine the rod insertion limits, AFD limits, and quadrant power tilt limits are not preserved. Therefore, the limits may not preserve the design peaking factors, and FQ(Z) and F N H must be verified directly by incore mapping.

Bases Section 3.2 (Power Distribution Limits) contains more complete discussions of the relation of FQ(Z) and F N H to the operating limits.

Shutdown and control rod OPERABILITY and alignment are directly related to power distributions and SDM, which are initial conditions assumed in safety analyses. Therefore they satisfy Criterion 2 of 10 CFR 50.36(c)(2)(ii).

Westinghouse STS B 3.1.4-3 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 BASES LCO The limits on shutdown or control rod alignments ensure that the assumptions in the safety analysis will remain valid. The requirements on control rod OPERABILITY ensure that upon reactor trip, the assumed reactivity will be available and will be inserted. The control rod OPERABILITY requirements (i.e., trippability) are separate from the alignment requirements, which ensure that the RCCAs and banks maintain the correct power distribution and rod alignment. The rod OPERABILITY requirement is satisfied provided the rod will fully insert in the required rod drop time assumed in the safety analysis. Rod control malfunctions that result in the inability to move a rod (e.g., rod lift coil failures), but that do not impact trippability, do not result in rod inoperability.

The requirement to maintain the rod alignment to within plus or minus 12 steps is conservative. The minimum misalignment assumed in safety analysis is 24 steps (15 inches), and in some cases a total misalignment from fully withdrawn to fully inserted is assumed.

Failure to meet the requirements of this LCO may produce unacceptable power peaking factors and LHRs, or unacceptable SDMs, all of which may constitute initial conditions inconsistent with the safety analysis.

APPLICABILITY The requirements on RCCA OPERABILITY and alignment are applicable in MODES 1 and 2 because these are the only MODES in which neutron (or fission) power is generated, and the OPERABILITY (i.e., trippability) and alignment of rods have the potential to affect the safety of the plant.

In MODES 3, 4, 5, and 6, the alignment limits do not apply because the control rods are bottomed and the reactor is shut down and not producing fission power. In the shutdown MODES, the OPERABILITY of the shutdown and control rods has the potential to affect the required SDM, but this effect can be compensated for by an increase in the boron concentration of the RCS. See LCO 3.1.1, "SHUTDOWN MARGIN (SDM)," for SDM in MODES 3, 4, and 5 and LCO 3.9.1, "Boron Concentration," for boron concentration requirements during refueling.

ACTIONS A.1.1 and A.1.2 When one or more rods are inoperable (i.e., untrippable), there is a possibility that the required SDM may be adversely affected. Under these conditions, it is important to determine the SDM, and if it is less than the required value, initiate boration until the required SDM is recovered. The 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 adequate for determining SDM and, if necessary, for initiating emergency boration and restoring SDM.

In this situation, SDM verification must include the worth of the untrippable rod, as well as a rod of maximum worth.

Westinghouse STS B 3.1.4-4 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 BASES ACTIONS (continued)

A.2 If the inoperable rod(s) cannot be restored to OPERABLE status, the plant must be brought to a MODE or condition in which the LCO requirements are not applicable. To achieve this status, the unit must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

The allowed Completion Time is reasonable, based on operating experience, for reaching MODE 3 from full power conditions in an orderly manner and without challenging plant systems.

B.1.1 and B.1.2 When a rod becomes misaligned, it can usually be moved and is still trippable. If the rod can be realigned within the Completion Time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, local xenon redistribution during this short interval will not be significant, and operation may proceed without further restriction.

An alternative to realigning a single misaligned RCCA to the group average position is to align the remainder of the group to the position of the misaligned RCCA. However, this must be done without violating the bank sequence, overlap, and insertion limits specified in LCO 3.1.5, "Shutdown Bank Insertion Limits," and LCO 3.1.6, "Control Bank Insertion Limits." The Completion Time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> gives the operator sufficient time to adjust the rod positions in an orderly manner.

B.2.1.1 and B.2.1.2 With a misaligned rod, SDM must be verified to be within limit or boration must be initiated to restore SDM to within limit.

In many cases, realigning the remainder of the group to the misaligned rod may not be desirable. For example, realigning control bank B to a rod that is misaligned 15 steps from the top of the core would require a significant power reduction, since control bank D must be moved fully in and control bank C must be moved in to approximately 100 to 115 steps.

Power operation may continue with one RCCA trippable but misaligned, provided that SDM is verified within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The Completion Time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> represents the time necessary for determining the actual unit SDM and, if necessary, aligning and starting the necessary systems and components to initiate boration.

Westinghouse STS B 3.1.4-5 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 BASES ACTIONS (continued)

B.2.2, B.2.3, B.2.4, B.2.5, and B.2.56 For continued operation with a misaligned rod, RTP must be reduced, SDM must periodically be verified within limits, hot channel factors (FQ(Z) and F N H ) must be verified within limits, and the safety analyses must be re-evaluated to confirm continued operation is permissible.

Reduction of power to 75% RTP ensures that local LHR increases due to a misaligned RCCA will not cause the core design criteria to be exceeded (Ref. 7). The Completion Time of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> gives the operator sufficient time to accomplish an orderly power reduction without challenging the Reactor Protection System.

When a rod is known to be misaligned, there is a potential to impact the SDM. Since the core conditions can change with time, periodic verification of SDM is required. A Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient to ensure this requirement continues to be met.

Verifying that FQ(Z), as approximated by F QC ( Z) and F WQ ( Z ) , and F N H are within the required limits ensures that current operation at 75% RTP with a rod misaligned is not resulting in power distributions that may invalidate safety analysis assumptions at full power. The Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allows sufficient time to obtain flux maps of the core power distribution using the incore flux mapping system and to calculate FQ(Z) and F N H .

Once current conditions have been verified acceptable, time is available to perform evaluations of accident analysis to determine that core limits will not be exceeded during a Design Basis Event for the duration of operation under these conditions. The accident analyses presented in FSAR Chapter 15 (Ref. 5) that may be adversely affected will be evaluated to ensure that the analysis results remain valid for the duration of continued operation under these conditions. A Completion Time of 5 days is sufficient time to obtain the required input data and to perform the analysis.

C.1 When Required Actions cannot be completed within their Completion Time, the unit must be brought to a MODE or Condition in which the LCO requirements are not applicable. To achieve this status, the unit must be brought to at least MODE 2 with Keff < 1.0 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, which Westinghouse STS B 3.1.4-6 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 BASES ACTIONS (continued) obviates concerns about the development of undesirable xenon or power distributions. The allowed Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is reasonable, based on operating experience, for reaching MODE 3 from full power conditions in an orderly manner and without challenging the plant systems.

D.1.1 and D.1.2 More than one control rod becoming misaligned from its group average position is not expected, and has the potential to reduce SDM. Therefore, SDM must be evaluated. One hour allows the operator adequate time to determine SDM. Restoration of the required SDM, if necessary, requires increasing the RCS boron concentration to provide negative reactivity, as described in the Bases or LCO 3.1.1. The required Completion Time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> for initiating boration is reasonable, based on the time required for potential xenon redistribution, the low probability of an accident occurring, and the steps required to complete the action. This allows the operator sufficient time to align the required valves and start the boric acid pumps.

Boration will continue until the required SDM is restored.

D.2 If more than one rod is found to be misaligned or becomes misaligned because of bank movement, the unit conditions fall outside of the accident analysis assumptions. Since automatic bank sequencing would continue to cause misalignment, the unit must be brought to a MODE or Condition in which the LCO requirements are not applicable. To achieve this status, the unit must be brought to at least MODE 2 with Keff < 1.0 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

The allowed Completion Time is reasonable, based on operating experience, for reaching MODE 2 with Keff < 1.0 from full power conditions in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.1.4.1 REQUIREMENTS

[ Verification that the position of individual rods positions are is within alignment limits at a Frequency [of 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />s] provides a history that allows the operator to detect a rod that is beginning to deviate from its expected position. The specified Frequency takes into account other rod position information that is continuously available to the operator in the control room, so that during actual rod motion, deviations can immediately be detected.

Westinghouse STS B 3.1.4-7 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 BASES SURVEILLANCE REQUIREMENTS (continued)

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

---

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

---

]

The SR is modified by a Note that permits it to not be performed for rods associated with an inoperable demand position indicator or an inoperable rod position indicator. The alignment limit is based on the demand position indicator which is not available if the indicator is inoperable.

LCO 3.1.7, "Rod Position Indication," provides Actions to verify the rods are in alignment when one or more rod position indicators are inoperable.

---

Reviewer's Note ----------------------------------------

The bracketed SR Note is only applicable to plants with an analog rod position indication system.

[The Surveillance is modified by a Note which states that the SR is not required to be performed until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after associated rod motion. Control rod temperature affects the accuracy of the rod position indication system. Due to changes in the magnetic permeability of the drive shaft as a function of temperature, the indicated position is expected to change with time as the drive shaft temperature changes. The one hour period allows control rod temperature to stabilize following rod movement in order to ensure the indicated rod position is accurate.]

SR 3.1.4.2 Verifying each control rod is OPERABLE would require that each rod be tripped. However, in MODES 1 and 2 with Keff 1.0, tripping each control rod would result in radial or axial power tilts, or oscillations. Exercising each individual control rod provides increased confidence that all rods continue to be OPERABLE without exceeding the alignment limit, even if they are not regularly tripped. Moving each control rod by 10 steps will not cause radial or axial power tilts, or oscillations, to occur. [ The 92 day Frequency takes into consideration other information available to the operator in the control room and SR 3.1.4.1, which is performed more frequently and adds to the determination of OPERABILITY of the rods.

Westinghouse STS B 3.1.4-8 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

---

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

---

]

Between required performances of SR 3.1.4.2 (determination of control rod OPERABILITY by movement), if a control rod(s) is discovered to be immovable, but remains trippable, the control rod(s) is considered to be OPERABLE. At any time, if a control rod(s) is immovable, a determination of the trippability (OPERABILITY) of the control rod(s) must be made, and appropriate action taken.

Westinghouse STS B 3.1.4-9 Rev. 4.0

TSTF-547, Rev. 1 Rod Group Alignment Limits B 3.1.4 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.1.4.3 Verification of rod drop times allows the operator to determine that the maximum rod drop time permitted is consistent with the assumed rod drop time used in the safety analysis. Measuring rod drop times prior to reactor criticality, after reactor vessel head removal, ensures that the reactor internals and rod drive mechanism will not interfere with rod motion or rod drop time, and that no degradation in these systems has occurred that would adversely affect control rod motion or drop time. This testing is performed with all RCPs operating and the average moderator temperature 500°F to simulate a reactor trip under actual conditions.

This Surveillance is performed during a plant outage, due to the plant conditions needed to perform the SR and the potential for an unplanned plant transient if the Surveillance were performed with the reactor at power.

REFERENCES 1. 10 CFR 50, Appendix A, GDC 10 and GDC 26.

2. 10 CFR 50.46.

3. FSAR, Chapter [15].

4. FSAR, Chapter [15].

5. FSAR, Chapter [15].

6. FSAR, Chapter [15].

7. FSAR, Chapter [15].

Westinghouse STS B 3.1.4-10 Rev. 4.0

TSTF-547, Rev. 1 Shutdown Bank Insertion Limits B 3.1.5 B 3.1 REACTIVITY CONTROL SYSTEMS B 3.1.5 Shutdown Bank Insertion Limits BASES BACKGROUND The insertion limits of the shutdown and control rods are initial assumptions in all safety analyses that assume rod insertion upon reactor trip. The insertion limits directly affect core power and fuel burnup distributions and assumptions of available ejected rod worth, SDM and initial reactivity insertion rate.

The applicable criteria for these reactivity and power distribution design requirements are 10 CFR 50, Appendix A, GDC 10, "Reactor Design,"

GDC 26, "Reactivity Control System Redundancy and Protection," GDC 28, "Reactivity Limits" (Ref. 1), and 10 CFR 50.46, "Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Reactors" (Ref. 2). Limits on control rod insertion have been established, and all rod positions are monitored and controlled during power operation to ensure that the power distribution and reactivity limits defined by the design power peaking and SDM limits are preserved.

The rod cluster control assemblies (RCCAs) are divided among control banks and shutdown banks. Each bank may be further subdivided into two groups to provide for precise reactivity control. A group consists of two or more RCCAs that are electrically paralleled to step simultaneously.

A bank of RCCAs consists of two groups that are moved in a staggered fashion, but always within one step of each other. All plants have four control banks and at least two shutdown banks. See LCO 3.1.4, "Rod Group Alignment Limits," for control and shutdown rod OPERABILITY and alignment requirements, and LCO 3.1.7, "Rod Position Indication," for position indication requirements.

The control banks are used for precise reactivity control of the reactor.

The positions of the control banks are normally automatically controlled by the Rod Control System, but they can also be manually controlled.

They are capable of adding negative reactivity very quickly (compared to borating). The control banks must be maintained above designed insertion limits and are typically near the fully withdrawn position during normal full power operations.

Hence, they are not capable of adding a large amount of positive reactivity. Boration or dilution of the Reactor Coolant System (RCS) compensates for the reactivity changes associated with large changes in RCS temperature. The design calculations are performed with the assumption that the shutdown banks are withdrawn first. The shutdown banks can be fully withdrawn without the core going critical. This provides available negative reactivity in the event of boration errors. The Westinghouse STS B 3.1.5-1 Rev. 4.0

TSTF-547, Rev. 1 Shutdown Bank Insertion Limits B 3.1.5 BASES BACKGROUND (continued) shutdown banks are controlled manually by the control room operator.

During normal unit operation, the shutdown banks are either fully withdrawn or fully inserted. The shutdown banks must be completely withdrawn from the core, prior to withdrawing any control banks during an approach to criticality. The shutdown banks are then left in this position until the reactor is shut down. They affect core power and burnup distribution, and add negative reactivity to shut down the reactor upon receipt of a reactor trip signal.

APPLICABLE On a reactor trip, all RCCAs (shutdown banks and control banks), except SAFETY the most reactive RCCA, are assumed to insert into the core. The ANALYSES shutdown banks shall be at or above their insertion limits and available to insert the maximum amount of negative reactivity on a reactor trip signal.

The control banks may be partially inserted in the core, as allowed by LCO 3.1.6, "Control Bank Insertion Limits." The shutdown bank and control bank insertion limits are established to ensure that a sufficient amount of negative reactivity is available to shut down the reactor and maintain the required SDM (see LCO 3.1.1, "SHUTDOWN MARGIN (SDM)") following a reactor trip from full power. The combination of control banks and shutdown banks (less the most reactive RCCA, which is assumed to be fully withdrawn) is sufficient to take the reactor from full power conditions at rated temperature to zero power, and to maintain the required SDM at rated no load temperature (Ref. 3). The shutdown bank insertion limit also limits the reactivity worth of an ejected shutdown rod.

The acceptance criteria for addressing shutdown and control rod bank insertion limits and inoperability or misalignment is that:

a. There be no violations of:

1. Specified acceptable fuel design limits or

2. RCS pressure boundary integrity and

b. The core remains subcritical after accident transients.

As such, the shutdown bank insertion limits affect safety analysis involving core reactivity and SDM (Ref. 3).

The shutdown bank insertion limits preserve an initial condition assumed in the safety analyses and, as such, satisfy Criterion 2 of 10 CFR 50.36(c)(2)(ii).

Westinghouse STS B 3.1.5-2 Rev. 4.0

TSTF-547, Rev. 1 Shutdown Bank Insertion Limits B 3.1.5 BASES LCO The shutdown banks must be within their insertion limits any time the reactor is critical or approaching criticality. This ensures that a sufficient amount of negative reactivity is available to shut down the reactor and maintain the required SDM following a reactor trip.

The shutdown bank insertion limits are defined in the COLR.

The LCO is modified by a Note indicating the LCO requirement is not applicable to shutdown banks being inserted while performing SR 3.1.4.2.

This SR verifies the freedom of the rods to move, and may require the shutdown bank to move below the LCO limits, which would normally violate the LCO. This Note applies to each shutdown bank as it is moved below the insertion limit to perform the SR. This Note is not applicable should a malfunction stop performance of the SR.

APPLICABILITY The shutdown banks must be within their insertion limits, with the reactor in MODES 1 and 2. This ensures that a sufficient amount of negative reactivity is available to shut down the reactor and maintain the required SDM following a reactor trip. The shutdown banks do not have to be within their insertion limits in MODE 3, unless an approach to criticality is being made. In MODE 3, 4, 5, or 6, the shutdown banks are fully inserted in the core and contribute to the SDM. Refer to LCO 3.1.1 for SDM requirements in MODES 3, 4, and 5. LCO 3.9.1, "Boron Concentration,"

ensures adequate SDM in MODE 6.

The Applicability requirements have been modified by a Note indicating the LCO requirement is suspended during SR 3.1.4.2. This SR verifies the freedom of the rods to move, and requires the shutdown bank to move below the LCO limits, which would normally violate the LCO.

ACTIONS A.1, A.2.1, A.2.2, and A.3

---

Reviewer's Note -------------------------------------

The bracketed number [16] in Condition A should be replaced with the plant-specific minimum number of steps that the rods must be moved to ensure correct performance of SR 3.1.4.2.

If one shutdown bank is inserted less than or equal to [16] steps below the insertion limit, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is allowed to restore the shutdown bank to within the limit. This is necessary because the available SDM may be reduced with a shutdown bank not within its insertion limit. Also, verification of SDM or initiation of boration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is required, since the SDM in MODES 1 and 2 is ensured by adhering to the control and shutdown bank insertion limits (see LCO 3.1.1). If a shutdown bank is not within its insertion limit, SDM will be verified by performing a reactivity balance calculation, considering the effects listed in the BASES for SR 3.1.1.1.

Westinghouse STS B 3.1.5-3 Rev. 4.0

TSTF-547, Rev. 1 Shutdown Bank Insertion Limits B 3.1.5 While the shutdown bank is outside the insertion limit, all control banks must be within their insertion limits to ensure sufficient shutdown margin is available. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time is sufficient to repair most rod control failures that would prevent movement of a shutdown bank.

BA.1.1, BA.1.2, and BA.2 When one or more shutdown banks is not within insertion limits for reasons other than Condition A, 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> is allowed to restore the shutdown banks to within the insertion limits. This is necessary because the available SDM may be significantly reduced, with one or more of the shutdown banks not within their insertion limits. Also, verification of SDM or initiation of boration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is required, since the SDM in MODES 1 and 2 is ensured by adhering to the control and shutdown bank insertion limits (see LCO 3.1.1). If shutdown banks are not within their insertion limits, then SDM will be verified by performing a reactivity balance calculation, considering the effects listed in the BASES for SR 3.1.1.1.

The allowed Completion Time of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> provides an acceptable time for evaluating and repairing minor problems without allowing the plant to remain in an unacceptable condition for an extended period of time.

CB.1 If the Required Actions and associated Completion Times are not met, shutdown banks cannot be restored to within their insertion limits within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, the unit must be brought to a MODE where the LCO is not applicable. The allowed Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is reasonable, based on operating experience, for reaching the required MODE from full power conditions in an orderly manner and without challenging plant systems.

Westinghouse STS B 3.1.5-4 Rev. 4.0

TSTF-547, Rev. 1 Shutdown Bank Insertion Limits B 3.1.5 BASES SURVEILLANCE SR 3.1.5.1 REQUIREMENTS Verification that the shutdown banks are within their insertion limits prior to an approach to criticality ensures that when the reactor is critical, or being taken critical, the shutdown banks will be available to shut down the reactor, and the required SDM will be maintained following a reactor trip.

This SR and Frequency ensure that the shutdown banks are withdrawn before the control banks are withdrawn during a unit startup.

---

Reviewer's Note ----------------------------------------

The bracketed SR Note is only applicable to plants with an analog rod position indication system.

[The Surveillance is modified by a Note which states that the SR is not required to be performed for shutdown banks until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after motion of rods in those banks. Rod temperature affects the accuracy of the rod position indication system. Due to changes in the magnetic permeability of the drive shaft as a function of temperature, the indicated position is expected to change with time as the drive shaft temperature changes.

The one hour period allows rod temperature to stabilize following rod movement in order to ensure the indicated position is accurate.]

[ Since the shutdown banks are positioned manually by the control room operator, a verification of shutdown bank position at a Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, after the reactor is taken critical, is adequate to ensure that they are within their insertion limits. Also, the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Frequency takes into account other information available in the control room for the purpose of monitoring the status of shutdown rods.

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

---

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

---

]

REFERENCES 1. 10 CFR 50, Appendix A, GDC 10, GDC 26, and GDC 28.

2. 10 CFR 50.46.

3. FSAR, Chapter [15].

Westinghouse STS B 3.1.5-5 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 B 3.1 REACTIVITY CONTROL SYSTEMS B 3.1.6 Control Bank Insertion Limits BASES BACKGROUND The insertion limits of the shutdown and control rods are initial assumptions in all safety analyses that assume rod insertion upon reactor trip. The insertion limits directly affect core power and fuel burnup distributions and assumptions of available SDM, and initial reactivity insertion rate.

The applicable criteria for these reactivity and power distribution design requirements are 10 CFR 50, Appendix A, GDC 10, "Reactor Design,"

GDC 26, "Reactivity Control System Redundancy and Protection," GDC 28, "Reactivity Limits" (Ref. 1), and 10 CFR 50.46, "Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Reactors" (Ref. 2). Limits on control rod insertion have been established, and all rod positions are monitored and controlled during power operation to ensure that the power distribution and reactivity limits defined by the design power peaking and SDM limits are preserved.

The rod cluster control assemblies (RCCAs) are divided among control banks and shutdown banks. Each bank may be further subdivided into two groups to provide for precise reactivity control. A group consists of two or more RCCAs that are electrically paralleled to step simultaneously.

A bank of RCCAs consists of two groups that are moved in a staggered fashion, but always within one step of each other. All plants have four control banks and at least two shutdown banks. See LCO 3.1.4, "Rod Group Alignment Limits," for control and shutdown rod OPERABILITY and alignment requirements, and LCO 3.1.7, "Rod Position Indication," for position indication requirements.

The control bank insertion limits are specified in the COLR. An example is provided for information only in Figure B 3.1.6-1. The control banks are required to be at or above the insertion limit lines.

Figure B 3.1.6-1 also indicates how the control banks are moved in an overlap pattern. Overlap is the distance travelled together by two control banks. The predetermined position of control bank C, at which control bank D will begin to move with bank C on a withdrawal, will be at 118 steps for a fully withdrawn position of 231 steps. The fully withdrawn position is defined in the COLR.

Westinghouse STS B 3.1.6-1 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 BASES BACKGROUND (continued)

The control banks are used for precise reactivity control of the reactor.

The positions of the control banks are normally controlled automatically by the Rod Control System, but can also be manually controlled. They are capable of adding reactivity very quickly (compared to borating or diluting).

The power density at any point in the core must be limited, so that the fuel design criteria are maintained. Together, LCO 3.1.4, LCO 3.1.5, "Shutdown Bank Insertion Limits," LCO 3.1.6, LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)," and LCO 3.2.4, "QUADRANT POWER TILT RATIO (QPTR)," provide limits on control component operation and on monitored process variables, which ensure that the core operates within the fuel design criteria.

The shutdown and control bank insertion and alignment limits, AFD, and QPTR are process variables that together characterize and control the three dimensional power distribution of the reactor core. Additionally, the control bank insertion limits control the reactivity that could be added in the event of a rod ejection accident, and the shutdown and control bank insertion limits ensure the required SDM is maintained.

Operation within the subject LCO limits will prevent fuel cladding failures that would breach the primary fission product barrier and release fission products to the reactor coolant in the event of a loss of coolant accident (LOCA), loss of flow, ejected rod, or other accident requiring termination by a Reactor Trip System (RTS) trip function.

APPLICABLE The shutdown and control bank insertion limits, AFD, and QPTR LCOs SAFETY are required to prevent power distributions that could result in fuel ANALYSES cladding failures in the event of a LOCA, loss of flow, ejected rod, or other accident requiring termination by an RTS trip function.

The acceptance criteria for addressing shutdown and control bank insertion limits and inoperability or misalignment are that:

a. There be no violations of:

1. Specified acceptable fuel design limits or

2. Reactor Coolant System pressure boundary integrity and

b. The core remains subcritical after accident transients.

Westinghouse STS B 3.1.6-2 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 BASES APPLICABLE SAFETY ANALYSES (continued)

As such, the shutdown and control bank insertion limits affect safety analysis involving core reactivity and power distributions (Ref. 3).

The SDM requirement is ensured by limiting the control and shutdown bank insertion limits so that allowable inserted worth of the RCCAs is such that sufficient reactivity is available in the rods to shut down the reactor to hot zero power with a reactivity margin that assumes the maximum worth RCCA remains fully withdrawn upon trip (Ref. 4).

Operation at the insertion limits or AFD limits may approach the maximum allowable linear heat generation rate or peaking factor with the allowed QPTR present. Operation at the insertion limit may also indicate the maximum ejected RCCA worth could be equal to the limiting value in fuel cycles that have sufficiently high ejected RCCA worths.

The control and shutdown bank insertion limits ensure that safety analyses assumptions for SDM, ejected rod worth, and power distribution peaking factors are preserved (Ref. 5).

The insertion limits satisfy Criterion 2 of 10 CFR 50.36(c)(2)(ii), in that they are initial conditions assumed in the safety analysis.

LCO The limits on control banks sequence, overlap, and physical insertion, as defined in the COLR, must be maintained because they serve the function of preserving power distribution, ensuring that the SDM is maintained, ensuring that ejected rod worth is maintained, and ensuring adequate negative reactivity insertion is available on trip. The overlap between control banks provides more uniform rates of reactivity insertion and withdrawal and is imposed to maintain acceptable power peaking during control bank motion.

The LCO is modified by a Note indicating the LCO requirement is not applicable to control banks being inserted while performing SR 3.1.4.2.

This SR verifies the freedom of the rods to move, and may require the control bank to move below the LCO limits, which would normally violate the LCO. This Note applies to each control bank as it is moved below the insertion limit to perform the SR. This Note is not applicable should a malfunction stop performance of the SR.

APPLICABILITY The control bank sequence, overlap, and physical insertion limits shall be maintained with the reactor in MODES 1 and 2 with keff 1.0. These limits must be maintained, since they preserve the assumed power distribution, ejected rod worth, SDM, and reactivity rate insertion assumptions. Applicability in MODES 3, 4, and 5 is not required, since neither the power distribution nor ejected rod worth assumptions would be exceeded in these MODES.

Westinghouse STS B 3.1.6-3 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 The applicability requirements have been modified by a Note indicating the LCO requirements are suspended during the performance of SR 3.1.4.2. This SR verifies the freedom of the rods to move, and requires the control bank to move below the LCO limits, which would violate the LCO.

Westinghouse STS B 3.1.6-4 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 BASES ACTIONS A.1, A.2.1, A.2.2, and A.3

---

Reviewer's Note -------------------------------------

The bracketed number [16] in Condition A should be replaced with the plant-specific minimum number of steps that encompasses the rod positions during performance of SR 3.1.4.2.

If Control Bank A, B, or C is inserted less than or equal to [16] steps below the insertion, sequence, or overlap limits, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is allowed to restore the control bank to within the limits. Verification of SDM or initiation of boration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is required, since the SDM in MODES 1 and 2 is ensured by adhering to the control and shutdown bank insertion limits (see LCO 3.1.1). If a control bank is not within its insertion limit, SDM will be verified by performing a reactivity balance calculation, considering the effects listed in the BASES for SR 3.1.1.1.

While the control bank is outside the insertion, sequence, or overlap limits, all shutdown banks must be within their insertion limits to ensure sufficient shutdown margin is available and that power distribution is controlled. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time is sufficient to repair most rod control failures that would prevent movement of a shutdown bank.

Condition A is limited to Control banks A, B, or C. The allowance is not required for Control Bank D because the full power bank insertion limit can be met during performance of the SR 3.1.4.2 control rod freedom of movement (trippability) testing.

BA.1.1, BA.1.2, BA.2, CB.1.1, CB.1.2, and CB.2 When the control banks are outside the acceptable insertion limits for reasons other than Condition A, they must be restored to within those limits. This restoration can occur in two ways:

a. Reducing power to be consistent with rod position or

b. Moving rods to be consistent with power.

Also, verification of SDM or initiation of boration to regain SDM is required within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, since the SDM in MODES 1 and 2 normally ensured by adhering to the control and shutdown bank insertion limits (see LCO 3.1.1, "SHUTDOWN MARGIN (SDM)") has been upset. If control banks are not within their insertion limits, then SDM will be verified by performing a reactivity balance calculation, considering the effects listed in the BASES for SR 3.1.1.1.

Westinghouse STS B 3.1.6-5 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 Similarly, if the control banks are found to be out of sequence or in the wrong overlap configuration for reasons other than Condition A, they must be restored to meet the limits.

Operation beyond the LCO limits is allowed for a short time period in order to take conservative action because the simultaneous occurrence of either a LOCA, loss of flow accident, ejected rod accident, or other accident during this short time period, together with an inadequate power distribution or reactivity capability, has an acceptably low probability.

The allowed Completion Time of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for restoring the banks to within the insertion, sequence, and overlaps limits provides an acceptable time for evaluating and repairing minor problems without allowing the plant to remain in an unacceptable condition for an extended period of time.

DC.1 If the Required Actions A.1 and A.2, or B.1 and B.2 cannot be completed within the associated Completion Times, the plant must be brought to MODE 2 with keff < 1.0, where the LCO is not applicable. The allowed Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is reasonable, based on operating experience, for reaching the required MODE from full power conditions in an orderly manner and without challenging plant systems.

Westinghouse STS B 3.1.6-6 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 BASES SURVEILLANCE SR 3.1.6.1 REQUIREMENTS This Surveillance is required to ensure that the reactor does not achieve criticality with the control banks below their insertion limits.

The estimated critical position (ECP) depends upon a number of factors, one of which is xenon concentration. If the ECP was calculated long before criticality, xenon concentration could change to make the ECP substantially in error. Conversely, determining the ECP immediately before criticality could be an unnecessary burden. There are a number of unit parameters requiring operator attention at that point. Performing the ECP calculation within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> prior to criticality avoids a large error from changes in xenon concentration, but allows the operator some flexibility to schedule the ECP calculation with other startup activities.

SR 3.1.6.2

[ Verification of the control bank insertion limits at a Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient to detect control banks that may be approaching the insertion limits since, normally, very little rod motion occurs in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

---

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

---

]

---

Reviewer's Note ----------------------------------------

The bracketed SR Note is only applicable to plants with an analog rod position indication system.

[The Surveillance is modified by a Note stating that the SR is not required to be performed for control banks until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after motion of rods in those banks. Control rod temperature affects the accuracy of the rod position indication system. Due to changes in the magnetic permeability of the drive shaft as a function of temperature, the indicated position is expected to change with time as the drive shaft temperature changes. The one hour period allows control rod temperature to stabilize following rod movement in order to ensure the indicated rod position is accurate.]

Westinghouse STS B 3.1.6-7 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 SR 3.1.6.3 When control banks are maintained within their insertion limits as checked by SR 3.1.6.2 above, it is unlikely that their sequence and overlap will not be in accordance with requirements provided in the COLR.

---

Reviewer's Note ----------------------------------------

The bracketed SR Note is only applicable to plants with an analog rod position indication system.

[The Surveillance is modified by a Note stating that the SR is not required to be performed for control banks until 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after motion of rods in those banks. Control rod temperature affects the accuracy of the rod position indication system. Due to changes in the magnetic permeability of the drive shaft as a function of temperature, the indicated position is expected to change with time as the drive shaft temperature changes. The one hour period allows control rod temperature to stabilize following rod movement in order to ensure the indicated rod position is accurate.]

[ A Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is consistent with the insertion limit check above in SR 3.1.6.2.

Westinghouse STS B 3.1.6-8 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 BASES SURVEILLANCE REQUIREMENTS (continued)

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

---

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

---

]

REFERENCES 1. 10 CFR 50, Appendix A, GDC 10, GDC 26, GDC 28.

2. 10 CFR 50.46.

3. FSAR, Chapter [15].

4. FSAR, Chapter [15].

5. FSAR, Chapter [15].

Westinghouse STS B 3.1.6-9 Rev. 4.0

TSTF-547, Rev. 1 Control Bank Insertion Limits B 3.1.6 Figure B 3.1.6 (page 1 of 1)

Control Bank Insertion vs. Percent RTP Westinghouse STS B 3.1.6-10 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 B 3.1 REACTIVITY CONTROL SYSTEMS B 3.1.7 Rod Position Indication BASES BACKGROUND According to GDC 13 (Ref. 1), instrumentation to monitor variables and systems over their operating ranges during normal operation, anticipated operational occurrences, and accident conditions must be OPERABLE.

LCO 3.1.7 is required to ensure OPERABILITY of the control rod position indicators to determine control rod positions and thereby ensure compliance with the control rod alignment and insertion limits.

The OPERABILITY, including position indication, of the shutdown and control rods is an initial assumption in all safety analyses that assume rod insertion upon reactor trip. Maximum rod misalignment is an initial assumption in the safety analysis that directly affects core power distributions and assumptions of available SDM. Rod position indication is required to assess OPERABILITY and misalignment.

Mechanical or electrical failures may cause a control rod to become inoperable or to become misaligned from its group. Control rod inoperability or misalignment may cause increased power peaking, due to the asymmetric reactivity distribution and a reduction in the total available rod worth for reactor shutdown. Therefore, control rod alignment and OPERABILITY are related to core operation in design power peaking limits and the core design requirement of a minimum SDM.

Limits on control rod alignment and OPERABILITY have been established, and all rod positions are monitored and controlled during power operation to ensure that the power distribution and reactivity limits defined by the design power peaking and SDM limits are preserved.

Rod cluster control assemblies (RCCAs), or rods, are moved out of the core (up or withdrawn) or into the core (down or inserted) by their control rod drive mechanisms. The RCCAs are divided among control banks and shutdown banks. Each bank may be further subdivided into two groups to provide for precise reactivity control.

The axial position of shutdown rods and control rods are determined by two separate and independent systems: the Bank Demand Position Indication System (commonly called group step counters) and the [Digital]

Rod Position Indication ([D]RPI) System.

Westinghouse STS B 3.1.7-1 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 BASES BACKGROUND (continued)

The Bank Demand Position Indication System counts the pulses from the Rod Control System that move the rods. There is one step counter for each group of rods. Individual rods 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 Bank Demand Position Indication System is considered highly precise (+/- 1 step or +/- e inch). If a rod does not move one step for each demand pulse, the step counter will still count the pulse and incorrectly reflect the position of the rod.

The [D]RPI System provides a highly accurate indication of actual control rod position, but at a lower precision than the step counters. This system is based on inductive analog signals from a series of coils spaced along a hollow tube with a center to center distance of 3.75 inches, which is 6 steps. To increase the reliability of the system, the inductive coils are connected alternately to data system A or B. Thus, if one system fails, the [D]RPI will go on half accuracy with an effective coil spacing of 7.5 inches, which is 12 steps. Therefore, the normal indication accuracy of the [D]RPI System is +/- 6 steps (+/- 3.75 inches), and the maximum uncertainty is +/- 12 steps (+/- 7.5 inches). With an indicated deviation of 12 steps between the group step counter and [D]RPI, the maximum deviation between actual rod position and the demand position could be 24 steps, or 15 inches.

APPLICABLE Control and shutdown rod position accuracy is essential during power SAFETY operation. Power peaking, ejected rod worth, or SDM limits may be ANALYSES violated in the event of a Design Basis Accident (Ref. 2), with control or shutdown rods operating outside their limits undetected. Therefore, the acceptance criteria for rod position indication is that rod positions must be known with sufficient accuracy in order to verify the core is operating within the group sequence, overlap, design peaking limits, ejected rod worth, and with minimum SDM (LCO 3.1.5, "Shutdown Bank Insertion Limits," and LCO 3.1.6, "Control Bank Insertion Limits"). The rod positions must also be known in order to verify the alignment limits are preserved (LCO 3.1.4, "Rod Group Alignment Limits"). Control rod positions are continuously monitored to provide operators with information that ensures the plant is operating within the bounds of the accident analysis assumptions.

The control rod position indicator channels satisfy Criterion 2 of 10 CFR 50.36(c)(2)(ii). The control rod position indicators monitor control rod position, which is an initial condition of the accident.

Westinghouse STS B 3.1.7-2 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 BASES LCO LCO 3.1.7 specifies that one [D]RPI System and one Bank Demand Position Indication System be OPERABLE for each control rod. For the control rod position indicators to be OPERABLE requires meeting the SR of the LCO and the following:

a. The [D]RPI System indicates within 12 steps of the group step counter demand position as required by LCO 3.1.4, "Rod Group Alignment Limits,"

b. For the [D]RPI System there are no failed coils, and

c. The Bank Demand Indication System has been calibrated either in the fully inserted position or to the [D]RPI System.

The 12 step agreement limit between the Bank Demand Position Indication System and the [D]RPI System indicates that the Bank Demand Position Indication System is adequately calibrated, and can be used for indication of the measurement of control rod bank position.

A deviation of less than the allowable limit, given in LCO 3.1.4, in position indication for a single control rod, ensures high confidence that the position uncertainty of the corresponding control rod group is within the assumed values used in the analysis (that specified control rod group insertion limits).

These requirements ensure that control rod position indication during power operation and PHYSICS TESTS is accurate, and that design assumptions are not challenged.

OPERABILITY of the position indicator channels ensures that inoperable, misaligned, or mispositioned control rods can be detected. Therefore, power peaking, ejected rod worth, and SDM can be controlled within acceptable limits.

---

Reviewer's Note ----------------------------------------

The bracketed LCO Note is only applicable to plants with an analog rod position indication system.

[The LCO is modified by a Note stating that the RPI system is not required to be met OPERABLE for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following movement of the associated rods. Control and shutdown rod temperature affects the accuracy of the RPI System. Due to changes in the magnetic permeability of the drive shaft as a function of temperature, the indicated position is expected to change with time as the drive shaft temperature changes. The one hour period allows temperature to stabilize following rod movement in order to ensure the indicated position is accurate.]

Westinghouse STS B 3.1.7-3 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 APPLICABILITY The requirements on the [D]RPI and step counters are only applicable in MODES 1 and 2 (consistent with LCO 3.1.4, LCO 3.1.5, and LCO 3.1.6),

because these are the only MODES in which power is generated, and the OPERABILITY and alignment of rods have the potential to affect the safety of the plant. In the shutdown MODES, the OPERABILITY of the shutdown and control banks has the potential to affect the required SDM, but this effect can be compensated for by an increase in the boron concentration of the Reactor Coolant System.

Westinghouse STS B 3.1.7-4 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 BASES ACTIONS The ACTIONS Table is modified by a Note indicating that a separate Condition entry is allowed for each inoperable rod position indicator and each demand position indicator. This is acceptable because the Required Actions for each Condition provide appropriate compensatory actions for each inoperable position indicator.

A.1, A.2.1, and A.2.2 When one [D]RPI channel per group in one or more groups fails, the position of the rod may still be determined indirectly by use of the movable incore detectors. The Required Action may also be satisfied by ensuring at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> that FQ satisfies LCO 3.2.1, F N H satisfies LCO 3.2.2, and SHUTDOWN MARGIN is within the limits provided in the COLR, provided the nonindicating rods have not been moved. Based on experience, normal power operation does not require excessive movement of banks. If a bank has been significantly moved, the Required Action of C.1 or C.2 below is required. Therefore, verification of RCCA position within the Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is adequate for allowing continued full power operation, since the probability of simultaneously having a rod significantly out of position and an event sensitive to that rod position is small.

Required Action A.1 requires verification of the position of a rod with an inoperable [D]RPI once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> which may put excessive wear and tear on the moveable incore detector system, Required Action A.2.1 provides an alternative. Required Action A.2.1 requires verification of rod position using the moveable incore detectors every 31 EFPD, which coincides with the normal use of the system to verify core power distribution.

Required Action A.2.1 includes six distinct requirements for verification of the position of rods associated with an inoperable [D]RPI using the movable incore detectors:

a. Initial verification within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the inoperability of the [D]RPI;

b. Re-verification once every 31 Effective Full Power Days (EFPD) thereafter;

c. Verification within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if rod control system parameters indicate unintended rod movement. An unintended rod movement is defined as the release of the rod's stationary gripper when no action was demanded either manually or automatically from the rod control system, or a rod motion in a direction other than the direction demanded by the rod control system. Verifying that no unintended rod movement has occurred is performed by monitoring the rod Westinghouse STS B 3.1.7-5 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 control system stationary gripper coil current for indications of rod movement;

d. Verification within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if the rod with an inoperable [D]RPI is intentionally moved greater than 12 steps;

e. Verification prior to exceeding 50% RTP if power is reduced below 50% RTP; and

f. Verification within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of reaching 100% RTP if power is reduced to less than 100% RTP.

Should the rod with the inoperable [D]RPI be moved more than 12 steps, or if reactor power is changed, the position of the rod with the inoperable

[D]RPI must be verified.

Required Action A.2.2 states that the inoperable [D]RPI must be restored to OPERABLE status prior to entering MODE 2 from MODE 3. The repair of the inoperable RPI must be performed prior to returning to power operation following a shutdown.

A.23 Reduction of THERMAL POWER to 50% RTP puts the core into a condition where rod position is not significantly affecting core peaking factors (Ref. 3).

The allowed Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is reasonable, based on operating experience, for reducing power to 50% RTP from full power conditions without challenging plant systems and allowing for rod position determination by Required Action A.1 above.

B.1, B.2, B.3, and B.24 When more than one [D]RPI per group in one or more groups fail, additional actions are necessary. to ensure that acceptable power distribution limits are maintained, minimum SDM is maintained, and the potential effects of rod misalignment on associated accident analyses are limited. Placing the Rod Control System in manual assures unplanned rod motion will not occur. Together with the indirect position determination available via Westinghouse STS B 3.1.7-6 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 BASES ACTIONS (continued) movable incore detectors will minimize the potential for rod misalignment.

The immediate Completion Time for placing the Rod Control System in manual reflects the urgency with which unplanned rod motion must be prevented while in this Condition.

Monitoring and recording reactor coolant Tavg help assure that significant changes in power distribution and SDM are avoided. The once per hour Completion Time is acceptable because only minor fluctuations in RCS temperature are expected at steady state plant operating conditions.

The position of the rods may be determined indirectly by use of the movable incore detectors. The Required Action may also be satisfied by ensuring at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> that FQ satisfies LCO 3.2.1, F N H satisfies LCO 3.2.2, and SHUTDOWN MARGIN is within the limits provided in the COLR, provided the nonindicating rods have not been moved. Verification of control rod position once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is adequate for allowing continued full power operation for a limited, 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, since the probability of simultaneously having a rod significantly out of position and an event sensitive to that rod position is small. The inoperable [D]RPIs must be restored, such that a maximum of one [D]RPI per group is inoperable, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time provides sufficient time to troubleshoot and restore the [D]RPI system to operation while avoiding the plant challenges associated with the shutdown without full rod position indication.

Based on operating experience, normal power operation does not require excessive rod movement. If one or more rods has been significantly moved, the Required Action of C.1 or C.2 below is required.

C.1 and C.2 With one [D]RPI inoperable in one or more groups and the affected groups have moved greater than 24 steps in one direction since the last determination of rod position, additional actions are needed to verify the position of rods within inoperable [D]RPI. Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, the position of the rods with inoperable position indication must be determined using the moveable incore detectors to verify These Required Actions clarify that when one or more rods with inoperable position indicators have been moved in excess of 24 steps in one direction, since the position was last determined, the Required Actions of A.1 and A.2, [or B.1, as applicable]

are still appropriate but must be initiated promptly under Required Action C.1 to begin verifying that these rods are still properly positioned, relative to their group positions.

Westinghouse STS B 3.1.7-7 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 If, within [4] hours, the rod positions have not been determined, THERMAL POWER must be reduced to 50% RTP within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to avoid undesirable power distributions that could result from continued operation at > 50% RTP, if one or more rods are misaligned by more than 24 steps. The allowed Completion Time of [4] hours provides an acceptable period of time to verify the rod positions.

Westinghouse STS B 3.1.7-8 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 BASES ACTIONS (continued)

D.1.1 and D.1.2 With one or more demand position indicators per bank inoperable in one or more banks, the rod positions can be determined by the [D]RPI System. Since normal power operation does not require excessive movement of rods, verification by administrative means that the rod position indicators are OPERABLE and the most withdrawn rod and the least withdrawn rod are 12 steps apart within the allowed Completion Time of once every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is adequate.

D.2 Reduction of THERMAL POWER to 50% RTP puts the core into a condition where rod position is not significantly affecting core peaking factor limits (Ref. 3). The allowed Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provides an acceptable period of time to verify the rod positions per Required Actions C.1.1 and C.1.2 or reduce power to 50% RTP.

E.1 If the Required Actions cannot be completed within the associated Completion Time, the plant must be brought to a MODE in which the requirement does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The allowed Completion Time is reasonable, based on operating experience, for reaching the required MODE from full power conditions in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.1.7.1 REQUIREMENTS Verification that the [D]RPI agrees with the demand position within

[12] steps ensures that the [D]RPI is operating correctly. Since the

[D]RPI does not display the actual shutdown rod positions between 18 and 210 steps, only points within the indicated ranges are required in comparison.

This Surveillance is performed prior to reactor criticality after each removal of the reactor head, as there is the potential for unnecessary plant transients if the SR were performed with the reactor at power.

The Surveillance is modified by a Note which states it is not required to be met for [D]RPIs associated with rods that do not meet LCO 3.1.4. If a rod is known to not to be within [12] steps of the group demand position, the ACTIONS of LCO 3.1.4 provide the appropriate Actions.

Westinghouse STS B 3.1.7-9 Rev. 4.0

TSTF-547, Rev. 1 Rod Position Indication B 3.1.7 BASES REFERENCES 1. 10 CFR 50, Appendix A, GDC 13.

2. FSAR, Chapter [15].

3. FSAR, Chapter [15].

Westinghouse STS B 3.1.7-10 Rev. 4.0