ML22240A042

From kanterella
Jump to navigation Jump to search
Changes Related to AP1000 Gts Subsection 3.3.7, RTS Trip Actuation Devices
ML22240A042
Person / Time
Issue date: 05/01/2015
From:
NRC/NRR/DSS/STSB
To:
Craig Harbuck NRR/DSS 301-415-3140
Shared Package
ML22240A001 List: ... further results
References
Download: ML22240A042 (33)
v • d • e


Text

GTST AP1000-O60-3.3.7, Rev. 1 Advanced Passive 1000 (AP1000)

Generic Technical Specification Traveler (GTST)

Title:

Changes Related to LCO 3.3.7, Reactor Trip System (RTS) Trip Actuation Devices I. Technical Specifications Task Force (TSTF) Travelers, Approved Since Revision 2 of STS NUREG-1431, and Used to Develop this GTST TSTF Number and

Title:

TSTF-411-A, Rev 1, Surveillance Test Interval Extensions for Components of the Reactor Protection System (WCAP-15376-P)

TSTF-418-A, Rev 2, RPS and ESFAS Test Times and Completion Times (WCAP-14333)

TSTF-519-T, Rev 0, Increase Standardization in Condition and Required Action Notes STS NUREGs Affected:

TSTF-411-A, Rev 1: NUREG 1431 TSTF-418-A, Rev 2: NUREG 1431 TSTF-519-T, Rev 0: NUREG 1430 and 1431 NRC Approval Date:

TSTF-411-A, Rev 1: 30-Aug-02 TSTF-418-A, Rev 2: 02-Apr-03 TSTF-519-T, Rev 0: 16-Oct-09 (TSTF Review)

TSTF Classification:

TSTF-411-A, Rev 1: Technical Change TSTF-418-A, Rev 2: Technical Change TSTF-519-T, Rev 0: NUREG Only Change Date report generated:

Friday, May 01, 2015 Page 1

GTST AP1000-O60-3.3.7, Rev. 1 II. Reference Combined License (RCOL) Standard Departures (Std. Dep.), RCOL COL Items, and RCOL Plant-Specific Technical Specifications (PTS) Changes Used to Develop this GTST RCOL Std. Dep. Number and

Title:

There are no Vogtle Electric Generating Plant Units 3 and 4 (Vogtle or VEGP) departures applicable to GTS 3.3.1.

RCOL COL Item Number and

Title:

There are no Vogtle COL items applicable to GTS 3.3.1.

RCOL PTS Change Number and

Title:

The VEGP License Amendment Request (LAR) proposed the following changes to the initial version of the PTS (referred to as the current TS by the VEGP LAR). These changes include Administrative Changes (A), Detail Removed Changes (D), Less Restrictive Changes (L), and More Restrictive Changes (M). These changes are discussed in Sections VI and VII of this GTST.

VEGP LAR DOC A024: Reformat of GTS 3.3.1 into Seven Parts; 3.3.1 through 3.3.7; note that this maps GTS 3.3.1 requirements into interim A024-modified TS (MTS) Subsection 3.3.7, to which the other changes are applied.

VEGP LAR DOC M02: Provision for Two or More Inoperable Divisions or Channels VEGP LAR DOC L07: Certain TS Required Actions Requiring the Reactor Trip Breakers (RTBs) to be Opened Are Revised into Two Required Actions VEGP LAR DOC D01: RTB Revisions Date report generated:

Friday, May 01, 2015 Page 2

GTST AP1000-O60-3.3.7, Rev. 1 III. Comments on Relations Among TSTFs, RCOL Std. Dep., RCOL COL Items, and RCOL PTS Changes This section discusses the considered changes that are: (1) applicable to operating reactor designs, but not to the AP1000 design; (2) already incorporated in the GTS; or (3) superseded by another change.

TSTF-411-A, Rev.1 provides justification to (1) increase the required action completion time and the bypass test time allowance for the reactor trip breakers and (2) increase the surveillance test intervals for the reactor trip breakers, master relays, logic cabinets, and analog channels based on analysis provided in WCAP-15376-P, Rev. 0, Risk-Informed Assessment of the RTS and ESFAS Surveillance Test Intervals and Reactor Trip Breaker Test and Completion Times.

WCAP-15376-P, Rev. 0 did not specifically consider the AP1000 design. The AP1000 GTS completion times and surveillance frequencies for instrumentation functions and reactor trip breakers were justified by APP-GW-GSC-020 (WCAP-16787), which is listed as Reference 6 in the GTS Subsection 3.3.2 Bases. Therefore, TSTF-411-A is not applicable to the AP1000 STS, and is not discussed further in this GTST.

TSTF-418-A adjusts the WOG STS (NUREG-1431) required action completion times for the conventional Westinghouse Plant Protection System instrumentation design for which the WOG STS instrumentation requirements are applicable. The changes in TSTF-418 are based on the analysis in WCAP-14333-P, which did not consider the AP1000 protection and safety monitoring system (PMS) instrumentation design. The AP1000 GTS required action completion times (and surveillance frequencies) for the PMS were justified by APP-GW-GSC-020 (WCAP-16787),

which is listed as Reference 6 in the GTS Subsection 3.3.2 Bases. APP-GW-GSC-020 does not reference WCAP-14333-P, but notes, the AP1000 protection and safety monitoring system (PMS) redundancy is as good as or better than that of the conventional Westinghouse Plant Protection System. Although the PMS equipment reliability is considered to be equivalent to or better than that of the conventional Westinghouse Plant Protection System, a common basis for comparison to the digital portion of the PMS is not readily available.

TSTF-519-T has already been incorporated into the AP1000 GTS regarding the Writer's Guide for Improved Standard Technical Specifications (Reference 4) placement of Notes in TS Actions tables.

Date report generated:

Friday, May 01, 2015 Page 3

GTST AP1000-O60-3.3.7, Rev. 1 IV. Additional Changes Proposed as Part of this GTST (modifications proposed by NRC staff and/or clear editorial changes or deviations identified by preparer of GTST)

APOG Recommended Changes to Improve the Bases For added clarity, revise the opening sentence of the ASA, LCO, and Applicability section of the Bases for STS Subsections 3.3.1 through 3.3.7 to state:

The RTS functions to maintain compliance with the SLs during all AOOs and mitigates the consequences of DBAs in all MODES in which the RTBs are closed.

Date report generated:

Friday, May 01, 2015 Page 4

GTST AP1000-O60-3.3.7, Rev. 1 V. Applicability Affected Generic Technical Specifications and Bases:

Section 3.3.7, Reactor Trip System (RTS) Trip Actuation Devices Changes to the Generic Technical Specifications and Bases:

GTS 3.3.1, Reactor Trip System (RTS) Instrumentation, is reformatted by VEGP DOC LAR A024 into multiple Specifications including interim A024-modified TS (MTS) 3.3.7, Reactor Trip System (RTS) Trip Actuation Devices. The reformatting relocates GTS 3.3.1 Function 17, Reactor Trip Breakers, and Function 18, Reactor Trip Breaker (RTB) Undervoltage and Shunt Trip Mechanisms, into MTS 3.3.7 as part of the LCO statement. The MTS format is depicted in Section XI of this GTST as the reference case in the markup of the GTS instrumentation requirements for the reactor trip system instrumentation.

MTS 3.3.7 LCO Title GTS 3.3.1 Function(s)

Reactor Trip System (RTS) 17. Reactor Trip Breakers Trip Actuation Devices 18. Reactor Trip Breaker (RTB) Undervoltage and Shunt Trip Mechanisms References 2, 3, and 6 provide details showing the correspondence of GTS 3.3.1 Functions and STS 3.3.1 through 3.3.7 Functions.

GTS 3.3.1 Conditions N and O are reordered and relabeled as AP1000 MTS 3.3.7 Conditions A, B, C, and D. No Function Table is required. (DOC A024)

GTS Table 3.3.1-1 footnote (a), With Reactor Trip Breakers (RTBs) closed and Plant Control System capable of rod withdrawal, applies to operation in MODEs 3, 4, and 5 for RTS Trip Actuation Devices. GTS Table 3.3.1-1 footnote (a) is incorporated into the MTS 3.3.7 LCO Applicability statement for MODEs 3, 4, and 5. (DOC A024)

In addition, the Applicability Statement for MODES 3, 4, and 5 (derived from GTS Table 3.3.1-1 footnote (a)) is revised to Plant Control System capable of rod withdrawal or one or more rods not fully inserted. This avoids undesirable plant secondary effects due to interlock actuation.

(DOC L07)

GTS SR 3.3.1.6 is retained and renumbered as MTS SR 3.3.7.1. (DOC A024)

MTS 3.3.7 Conditions C and D are revised by adding a second condition statement for the condition one or both Functions within three or more divisions inoperable. Otherwise, LCO 3.0.3 would apply when the LCO is not met and the associated Actions are not met or an associated Action is not provided. (DOC M02)

The requirement to open RTBs associated with MTS 3.3.7 Condition D is replaced by two Actions to initiate action to fully insert all rods and place the Plant Control System in a condition incapable of rod withdrawal. This provides flexibility to avoid potentially undesirable effects of opening RTBs and initiating certain interlocks. (DOC L07)

Date report generated:

Friday, May 01, 2015 Page 5

GTST AP1000-O60-3.3.7, Rev. 1 MTS SR 3.3.7.1 is rewritten to move the Note stating This Surveillance must be performed on both reactor trip breakers associated with a single division, into the Surveillance text to state Perform TADOT on both reactor trip breakers in one division. (DOC D01)

The Bases are revised to reflect these changes.

The following tables are provided as an aid to tracking the various changes to GTS 3.3.1 Conditions, Required Actions, Functions, Applicability Footnotes, and Surveillance Requirements that result in interim A024-modified TS (MTS) 3.3.7 and as further changed, STS 3.3.7.

Changes to Conditions GTS 3.3.1 MTS 3.3.7 STS 3.3.7 Other STS Subsections Additional Condition Condition Condition Addressing the Listed Condition DOC Changes A 3.3.1 ---

B 3.3.5 ---

C 3.3.5 ---

D 3.3.1 ---

E 3.3.1 ---

F 3.3.3 ---

G 3.3.3 ---

H 3.3.3 ---

I 3.3.2 ---

J 3.3.2 ---

K 3.3.1 ---

L 3.3.4, 3.3.6 ---

M 3.3.1 ---

N A A GTS Condition N split into 3 Conditions ---

N C C --- M02 N D D --- M02 L07 O B B --- L07 P 3.3.4, 3.3.6 ---

Q 3.3.2 ---

R 3.3.2 ---

Changes to Functions

Function [Modes(footnote)] ----------- STS 3.3.7 Other STS Subsections Additional GTS 3.3.1 MTS 3.3.7 STS 3.3.7 Conditions and Additional Changes DOC Changes 17 [1,2,3(a),4(a),5(a)] LCO 3.3.7 LCO 3.3.7 A, B, C --- D01 18 [1,2,3(a),4(a),5(a)] LCO 3.3.7 LCO 3.3.7 A, B, D --- D01 Changes to Applicability Footnotes GTS 3.3.1 MTS 3.3.7 STS 3.3.7 STS 3.3.7 STS Subsections Also Additional Changes Footnote Footnote Footnote Function Addressing Listed footnote DOC Number a -----LCO Applicability----- --- 3.3.2, 3.3.4, 3.3.5, 3.3.6 L07 Changes to Surveillance Requirements GTS 3.3.1 MTS 3.3.7 STS 3.3.7 STS Subsections Also Example Surveillance No.

SR SR SR Addressing the Listed SR Surveillance Description 3.3.1.1 3.3.1, 3.3.2, 3.3.3 3.3.1.1 CHANNEL CHECK 3.3.1.2 3.3.1 3.3.1.2 Compare calorimetric heat balance to NI channel output 3.3.1.3 3.3.1 3.3.1.3 Compare calorimetric heat balance to delta-T power calculation 3.3.1.4 3.3.1 3.3.1.4 Compare incore detector measurement to NI AXIAL FLUX DIFFERENCE 3.3.1.5 3.3.1 3.3.1.5 Calibrate excore channels Date report generated:

Friday, May 01, 2015 Page 6

GTST AP1000-O60-3.3.7, Rev. 1 GTS 3.3.1 MTS 3.3.7 STS 3.3.7 STS Subsections Also Example Surveillance No.

SR SR SR Addressing the Listed SR Surveillance Description 3.3.1.6 3.3.7.1 3.3.7.1 --- 3.3.7.1 Perform TADOT 3.3.1.7 3.3.4, 3.3.6 3.3.4.1 ACTUATION LOGIC TEST 3.3.1.8 3.3.1, 3.3.2 3.3.1.6 Perform COT 3.3.1.9 3.3.1, 3.3.2, 3.3.3 3.3.1.7 Perform COT 3.3.1.10 3.3.1 3.3.1.8 CHANNEL CALIBRATION 3.3.1.11 3.3.1, 3.3.2, 3.3.3 3.3.1.9 CHANNEL CALIBRATION 3.3.1.12 3.3.1, 3.3.5 3.3.1.10 Perform TADOT 3.3.1.13 3.3.1, 3.3.2, 3.3.3 3.3.1.11 Verify RTS RESPONSE TIME within limits The opening sentence of the ASA, LCO, and Applicability section of the Bases for STS Subsections 3.3.1 through 3.3.7 is revised to provide additional clarity. (APOG Comment)

Date report generated:

Friday, May 01, 2015 Page 7

GTST AP1000-O60-3.3.7, Rev. 1 VI. Traveler Information Description of TSTF changes:

Not Applicable Rationale for TSTF changes:

Not Applicable Description of changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes:

The Vogtle Electric Generating Plant Units 3 and 4 (VEGP) technical specifications upgrade (TSU) License Amendment Request (VEGP TSU LAR) (Reference 2) proposed changes to the initial version of the VEGP PTS (referred to as the current TS by the VEGP TSU LAR). As detailed in VEGP TSU LAR Enclosure 1, administrative change number 24 (DOC A024) reformats PTS 3.3.1 into multiple Specifications as follows:

Since PTS 3.3.1, Reactor Trip System (RTS) Instrumentation, is identical to GTS 3.3.1, it is appropriate for this GTST to consider the proposed changes to PTS 3.3.1 as changes to GTS 3.3.1 for incorporation in AP1000 STS 3.3.7. VEGP LAR DOC A024 is extensive, but retains the intention of PTS 3.3.1 while improving operational use of the TS. The numerous Functions, Conditions and extensive bases discussion associated with PTS 3.3.1 are repackaged into seven smaller parts. Therefore, the changes implemented by DOC A024 are presented in the attached Subsection 3.3.7 markup, in Section XI of this GTST, as the clean starting point for this GTST and are identified as interim A024-modified TS (MTS) 3.3.7. The specific details of the reformatting for MTS 3.3.7 can be found in VEGP TSU LAR (Reference 2), in Enclosure 2 (markup) and Enclosure 4 (clean). The NRC staff safety evaluation regarding DOC A024 can be found in Reference 3, VEGP LAR SER. The VEGP TSU LAR was modified in response to NRC staff RAIs in Reference 5 and the Southern Nuclear Operating Company RAI Response in Reference 6.

VEGP LAR DOC M02 addresses the fact that MTS 3.3.7, Reactor Trip System (RTS) Trip Actuation Devices, does not specify Actions for inoperability of more than two channels. This results in entry into LCO 3.0.3 when three or more channels are inoperable.

VEGP LAR DOC L07 revises the single action step to open the RTBs into a two-step process to initiate action to fully insert all rods, and place the Plant Control System in a condition incapable of rod withdrawal.

Date report generated:

Friday, May 01, 2015 Page 8

GTST AP1000-O60-3.3.7, Rev. 1 VEGP LAR DOC D01 revises the MTS SR 3.3.7.1 Note from This Surveillance must be performed on both reactor trip breakers associated with a single division, to Perform TADOT on both reactor trip breakers in one division.

A more detailed description of the changes by each of the above DOCs can be found in Reference 2, VEGP TSU LAR in Enclosure 1; the NRC staff safety evaluation can be found in Reference 3, VEGP LAR SER. The VEGP TSU LAR was modified in response to NRC staff RAIs (Reference 5) by Southern Nuclear Operating Companys RAI Response in Reference 6.

Rationale for changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes:

The reformatting per VEGP LAR DOC A024, except where addressed in other DOCs, addresses inconsistencies in formatting and approach between PTS 3.3.1 and PTS 3.3.2, respectively. Simplification and clarification are proposed for each Specification. In breaking down each PTS Specification into specific subsets of the Protection and Safety Monitoring System (PMS) function, improved human factored operator usability results.

These improvements also reflect the general approach currently in use in the Improved Standard Technical Specifications (STS) for Babcock and Wilcox Plants, NUREG-1430, Rev. 4.

That is to separate the functions for [sensor] instrumentation, Manual Actuation, Trip/Actuation Logic, and Trip Actuation Devices (e.g., Reactor Trip Breakers (RTBs)) into separate Specification subsections. Furthermore, the Actions for some ESFAS Functions generally involve a more complex presentation than needed for other Functions, such that simple common Actions are not reasonable. Such Functions are also provided with separate Specification subsections.

When TS instrument function tables are utilized to reference Actions, the generally preferred format of the Actions for an instrumentation Specification in NUREG-1430 is to provide the initial Actions that would be common to all of the specified functions (typically for bypassing and/or tripping one or two inoperable channels), then the default Action would direct consulting the function table for follow-on Actions applicable to the specific affected function. These follow-up Actions generally reflect the actions to exit the Applicability for that function.

This format also allows splitting the default Actions from the initial preferred actions. This general approach is the standard format for other Specifications and for Instrumentation Specifications for other vendors Improved STS.

VEGP LAR DOC M02 directly provides for the default Actions of LCO 3.0.3 without allowing for the additional hour that LCO 3.0.3 permits prior to initiating shutdown. This provides clarity for the operator and is more restrictive than LCO 3.0.3.

When the RTBs are opened, certain other interlocks can be initiated. The initiation of the associated interlocks may have an undesirable secondary effect on the ease of operation of the plant such as the initiation of the P-4 interlock, which, in the event of low Reactor Coolant System (RCS) temperature, can result in isolation of main feedwater to the steam generators.

VEGP LAR DOC L07 provides additional operator flexibility to achieve the same intent as opening the RTBs.

VEGP LAR DOC D01 allows that specific design details are not necessary for assuring operability or compliance with TS Actions. Removal of the channel design detail is consistent with PTS Conditions N and O that are based on division Operability, not individual component Operability.

Date report generated:

Friday, May 01, 2015 Page 9

GTST AP1000-O60-3.3.7, Rev. 1 Description of additional changes proposed by NRC staff/preparer of GTST:

The opening sentence of the ASA, LCO, and Applicability section of the Bases for STS Subsections 3.3.1 through 3.3.7 is revised to state:

The RTS functions to maintain compliance with the SLs during all AOOs and mitigates the consequences of DBAs in all MODES in which the RTBs are closed. (APOG Comment)

Rationale for additional changes proposed by NRC staff/preparer of GTST:

The opening sentence of the ASA, LCO, and Applicability section of the Bases for STS Subsections 3.3.1 through 3.3.7 is revised for additional clarity.

Date report generated:

Friday, May 01, 2015 Page 10

GTST AP1000-O60-3.3.7, Rev. 1 VII. GTST Safety Evaluation Technical Analysis:

AP1000 GTS LCO 3.0.3 is only applicable in MODES 1, 2, 3, and 4, and states:

When an LCO is not met and the associated ACTIONS are not met, an associated ACTION is not provided, or if directed by the associated ACTIONS, the unit shall be placed in a MODE or other specified condition in which the LCO is not applicable. Action shall be initiated within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to place the unit, as applicable,

a. MODE 3 within 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />; and
b. MODE 4 within 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br />; and
c. MODE 5 within 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br />.

GTS 3.3.1 and 3.3.2 Functions with applicability statements that include MODE 1, 2, 3, or 4, generally have no Actions specified for addressing a loss of function condition, such as when all required channels are inoperable. Upon discovery of such a condition, LCO 3.0.3 would apply.

The intent of LCO 3.0.3 (as stated in the TS Bases) is to impose time limits for placing the unit in a safe MODE or other specified condition when operation cannot be maintained within the limits for safe operation as defined by the LCO and its ACTIONS.

The Actions for inoperable RTS and ESFAS instrumentation provide restoration time and/or compensatory action allowances (e.g., place the inoperable channel in trip); but only for inoperability of some of the channels (e.g., 1 or 2 out of 4 required channels, typically). If these restoration and/or compensatory actions cannot be met in the required time, default actions are provided, which are designed to place the unit in a safe MODE or other specified condition -

typically, actions that result in exiting the Applicability for that Function.

The shutdown actions of LCO 3.0.3 are typical of default actions throughout the TS that direct plant shutdown to exit the Applicability, with the exception that LCO 3.0.3 includes an additional 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> before the shutdown is required to be initiated.

The revisions described in VEGP LAR DOC M02 address multiple-channel inoperability. The revisions will immediately impose the default Actions for that Function - without allowance for the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> delay that is provided in LCO 3.0.3. Furthermore, the Function-specific default actions (currently, or proposed to be, specified for some Functions) impose requirements intended to establish safe operation that are not necessarily required by LCO 3.0.3. Since each Function-specific default action is specifically considering that Functions safety-basis, such default actions necessarily result in more appropriate actions than the general default actions of LCO 3.0.3. Specifically, the Actions for each new Condition associated with VEGP LAR DOC M02 for RTS and ESFAS Functions applicable in MODES1, 2, 3, or 4, are compared to LCO 3.0.3, and in each case, the new Actions are equivalent to or more restrictive than the actions of LCO 3.0.3.

STS 3.3.7, Condition C leads to a new default action to be in Mode 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (from Mode 1 or 2), which is more restrictive than the time allowed by LCO 3.0.3. Further default actions of Condition D require initiating action to fully insert all rods within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and placing the Plant Control System in a condition incapable of rod withdrawal within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (from MODE 3, 4, or 5),

which are actions not required by LCO 3.0.3.

Date report generated:

Friday, May 01, 2015 Page 11

GTST AP1000-O60-3.3.7, Rev. 1 GTS 3.3.1 and 3.3.2 actions do not specify conditions that explicitly address multiple inoperable channels (that is, more than two inoperable channels or divisions, in most cases), and therefore default to LCO 3.0.3. In each instance, the proposed actions to address these conditions are more restrictive than the LCO 3.0.3 actions because completion times for reaching lower operational modes are shorter by 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In addition, Function-specific actions, where specified, are more appropriate for the affected Function than the unit-shutdown actions of LCO 3.0.3 alone. Therefore, the changes specified by VEGP LAR DOC M02 do not introduce any adverse impact on public health and safety.

VEGP LAR DOC L07 revises the Action to open the RTBs into a two-step process to initiate action to fully insert all rods, and place the Plant Control System in a condition incapable of rod withdrawal. Each of the PTS 3.3.1 required actions to open the reactor trip breakers (RTBs) is intended to ensure that control rods cannot be withdrawn thereby eliminating the possibility for control rod related positive reactivity additions and associated heat input into the reactor coolant. Additionally, all control rods are inserted by opening the RTBs. Therefore, replacing each required action to open RTBs with the two actions, which require initiating action to fully insert all rods and placing the Plant Control System in a condition incapable of rod withdrawal, maintains the intent of the existing PTS action requirements. VEGP LAR DOC L07 replaces the specific method of precluding rod withdrawal and ensuring all rods are inserted while maintaining the requirement for establishing the plant conditions equivalent to opening the RTBs. The revised actions still ensure rod withdrawal is precluded and all rods are inserted; therefore, the detail to open the RTBs is not required to be in the TS to provide adequate protection of the public health and safety.

To ensure that when the revised required actions are taken the unit is removed from the operational modes or other specified conditions in the Specifications Applicability, conforming revisions to the Applicability statements are made. The equivalent condition to the PTS Applicability statements that include RTBs closed is the condition of Plant Control System capable of rod withdrawal. However, since rods could have been withdrawn prior to making the Plant Control System incapable of rod withdrawal, the revised Specifications include the additional condition of or one or more rods not fully inserted. This change also aligns with the required actions to both fully insert all rods and place the Plant Control System in a condition incapable of rod withdrawal. The equivalent condition to the PTS Applicability statements that include RTBs open is the condition of Plant Control System capable of rod withdrawal and all rods fully inserted.

Removing the specific method of precluding rod withdrawal and establishing all rods inserted, and defining this condition solely in terms of the RTB status, from the TS is acceptable because this type of information is not necessary to be included to provide adequate protection of public health and safety. STS 3.3.5 retains requirements to ensure that control rod withdrawal is prohibited and all rods are inserted, when required.

VEGP LAR DOC D01 rewrites the MTS 3.3.7 SR 3.3.7.1 Note stating This Surveillance must be performed on both reactor trip breakers associated with a single division, into the Surveillance text to state Perform TADOT on both reactor trip breakers in one division. The design provides eight reactor trip breakers (RTBs) arranged in four divisions with two RTBs per division. Each RTB is equipped with an undervoltage trip attachment and a shunt trip device.

PTS 3.3.1 Conditions N and O, which become Conditions A and B in MTS 3.3.7, for inoperability of these Functions references inoperable divisions. Any breaker or trip device inoperability will result in entry into the Actions. The specific design details are not necessary for assuring operability or compliance with TS Actions. Removal of the channel design detail is consistent with PTS 3.3.1 Conditions N and O that are based on division operability, not individual component operability.

Date report generated:

Friday, May 01, 2015 Page 12

GTST AP1000-O60-3.3.7, Rev. 1 GTS SR 3.3.1.6 is performed on a Staggered Test Basis, based on the number of divisions.

Testing the two reactor trip breakers in the division for each surveillance interval is currently stated in the PTS Note. However, Surveillance Notes typically (refer to Improved TS Writers Guide, TSTF GG 05 01, subsection 4.1.7.d [Reference 4]) allow a limited exception to the Surveillance Requirement acceptance criteria or requirement to perform. In this case, the Note is stating expected attributes of each test and that is better presented within the Surveillance text. Rewriting the Note into the MTS SR 3.3.7.1 still retains the requirement for performing the Trip Actuating Device Operational Test (TADOT) on both reactor trip breakers within the division.

VEGP LAR DOC D01 is acceptable because these types of design and procedural details are adequately controlled in the FSAR and TS Bases.

The remaining changes, including VEGP LAR DOC A024, are editorial, clarifying, grammatical, or otherwise considered administrative. These changes do not affect the technical content, but improve the readability, implementation, and understanding of the requirements, and are therefore acceptable.

Having found that this GTSTs proposed changes to the GTS and Bases are acceptable, the NRC staff concludes that AP1000 STS Subsection 3.3.7 is an acceptable model Specification for the AP1000 standard reactor design.

References to Previous NRC Safety Evaluation Reports (SERs):

None Date report generated:

Friday, May 01, 2015 Page 13

GTST AP1000-O60-3.3.7, Rev. 1 VIII. Review Information Evaluator Comments:

None Randy Belles Oak Ridge National Laboratory 865-574-0388 bellesrj@ornl.gov Review Information:

Availability for public review and comment on Revision 0 of this traveler approved by NRC staff on 5/29/2014.

APOG Comments (Ref. 7) and Resolutions:

1. (Internal # 3) Throughout the Bases, references to Sections and Chapters of the FSAR do not include the FSAR clarifier. Since these Section and Chapter references are to an external document, it is appropriate (DOC A003) to include the FSAR modifier. This is resolved by adding the FSAR modifier as appropriate.
2. (Internal # 6) The GTST sections often repeat VEGP LAR DOCs, which reference existing and current requirements. The inclusion in the GTST of references to existing and current, are not always valid in the context of the GTS. Each occurrence of existing and current should be revised to be clear and specific to GTS, MTS, or VEGP COL TS (or other), as appropriate. Noted ambiguities are corrected in the GTST body.
3. (Internal # 7)Section VII, GTST Safety Evaluation, inconsistently completes the subsection References to Previous NRC Safety Evaluation Reports (SERs) by citing the associated SE for VEGP 3&4 COL Amendment 13. It is not clear whether there is a substantive intended difference when omitting the SE citation. This is resolved by removing the SE citation in Section VII of the GTST and ensuring that appropriate references to the consistent citation of this reference in Section X of the GTST are made.
4. (Internal # 116) In GTST for Subsection 3.3.7,Section VI, under the heading Rationale for changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes, the first paragraph mentions DOC A028. This DOC is for changes to ESFAS TS and does not affect Subsection 3.3.7. Note that it is not mentioned anywhere else in this Subsection. This is also stated in Subsections 3.3.1 through 3.3.6. Change DOCs A024 and A028 to DOC A024 in GTST 3.3.1 through GTST 3.3.7. This is resolved by making the recommended change.
5. (Internal # 126) In the ASA, LCO, and Applicability section of the Bases for STS Subsections 3.3.1 through 3.3.7, revise the opening sentence to state:

The RTS functions to maintain compliance with the SLs during all AOOs and mitigates the consequences of DBAs in all MODES in which the RTBs are closed This provides additional clarity. This is resolved by making the recommended change.

Date report generated:

Friday, May 01, 2015 Page 14

GTST AP1000-O60-3.3.7, Rev. 1

6. (Internal # 162) In GTST Section VII under the heading GTST Safety Evaluation the sixth paragraph, first sentence incorrectly cites both Conditions B and C. The correct citation is to only Condition C. The second sentence appropriately deals with Condition D. Also, the second sentence states that the default actions require fully inserting all rods and placing the Plant Control System in a condition incapable of rod withdrawal must be done in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The time for these Actions is actually 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In addition, the first action is not to require fully inserting all rods, but to initiating action to fully insert all rods. Replace the sixth paragraph with the following:

STS 3.3.7, Condition C leads to a new default action to be in Mode 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (from Mode 1 or 2), which is more restrictive than the time allowed by LCO 3.0.3. Further default actions of Condition D require initiating action to fully insert all rods within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and placing the Plant Control System in a condition incapable of rod withdrawal within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (from MODE 3, 4, or 5),

which are actions not required by LCO 3.0.3.

This is resolved by making the recommended change.

NRC Final Approval Date: May 1, 2015 NRC

Contact:

C. Craig Harbuck United States Nuclear Regulatory Commission 301-415-3140 Craig.Harbuck@nrc.gov Date report generated:

Friday, May 01, 2015 Page 15

GTST AP1000-O60-3.3.7, Rev. 1 IX. Evaluator Comments for Consideration in Finalizing Technical Specifications and Bases None Date report generated:

Friday, May 01, 2015 Page 16

GTST AP1000-O60-3.3.7, Rev. 1 X. References Used in GTST

1. AP1000 DCD, Revision 19, Section 16, Technical Specifications, June 2011 (ML11171A500).
2. Southern Nuclear Operating Company, Vogtle Electric Generating Plant, Units 3 and 4, Technical Specifications Upgrade License Amendment Request, February 24, 2011 (ML12065A057).
3. NRC Safety Evaluation (SE) for Amendment No. 13 to Combined License (COL) No.

NPF-91 for Vogtle Electric Generating Plant (VEGP) Unit 3, and Amendment No. 13 to COL No. NPF-92 for VEGP Unit 4, September 9, 2013, ADAMS Package Accession No. ML13238A337, which contains:

ML13238A355 Cover Letter - Issuance of License Amendment No. 13 for Vogtle Units 3 and 4 (LAR 12-002).

ML13238A359 Enclosure 1 - Amendment No. 13 to COL No. NPF-91 ML13239A256 Enclosure 2 - Amendment No. 13 to COL No. NPF-92 ML13239A284 Enclosure 3 - Revised plant-specific TS pages (Attachment to Amendment No. 13)

ML13239A287 Enclosure 4 - Safety Evaluation (SE), and Attachment 1 - Acronyms ML13239A288 SE Attachment 2 - Table A - Administrative Changes ML13239A319 SE Attachment 3 - Table M - More Restrictive Changes ML13239A333 SE Attachment 4 - Table R - Relocated Specifications ML13239A331 SE Attachment 5 - Table D - Detail Removed Changes ML13239A316 SE Attachment 6 - Table L - Less Restrictive Changes The following documents were subsequently issued to correct an administrative error in Enclosure 3:

ML13277A616 Letter - Correction To The Attachment (Replacement Pages) - Vogtle Electric Generating Plant Units 3 and 4-Issuance of Amendment Re:

Technical Specifications Upgrade (LAR 12-002) (TAC No. RP9402)

ML13277A637 Enclosure 3 - Revised plant-specific TS pages (Attachment to Amendment No. 13) (corrected)

4. TSTF-GG-05-01, Writer's Guide for Plant-Specific Improved Technical Specifications, June 2005.
5. RAI Letter No. 01 Related to License Amendment Request (LAR)12-002 for the Vogtle Electric Generating Plant Units 3 and 4 Combined Licenses, September 7, 2012 (ML12251A355).
6. Southern Nuclear Operating Company, Vogtle Electric Generating Plant, Units 3 and 4, Response to Request for Additional Information Letter No. 01 Related to License Amendment Request LAR-12-002, ND-12-2015, October 04, 2012 (ML12286A363 and ML12286A360)

Date report generated:

Friday, May 01, 2015 Page 17

GTST AP1000-O60-3.3.7, Rev. 1

7. APOG-2014-008, APOG (AP1000 Utilities) Comments on AP1000 Standardized Technical Specifications (STS) Generic Technical Specification Travelers (GTSTs), Docket ID NRC-2014-0147, September 22, 2014 (ML14265A493).

Date report generated:

Friday, May 01, 2015 Page 18

GTST AP1000-O60-3.3.7, Rev. 1 XI. MARKUP of the Applicable GTS Subsection for Preparation of the STS NUREG The entire section of the Specifications and the Bases associated with this GTST is presented next.

Changes to the Specifications and Bases are denoted as follows: Deleted portions are marked in strikethrough red font, and inserted portions in bold blue font.

Date report generated:

Friday, May 01, 2015 Page 19

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices 3.3.7 3.3 INSTRUMENTATION 3.3.7 Reactor Trip System (RTS) Trip Actuation Devices LCO 3.3.7 Four divisions of RTS trip actuation devices for the following Functions shall be OPERABLE:

a. Reactor Trip Breakers (RTBs); and
b. RTB Undervoltage and Shunt Trip Mechanisms.

APPLICABILITY: MODES 1 and 2, MODES 3, 4, and 5 with RTBs closed and Plant Control System capable of rod withdrawal or one or more rods not fully inserted.

ACTIONS

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

Separate Condition entry is allowed for each Function.

CONDITION REQUIRED ACTION COMPLETION TIME A. One or both Functions A.1 Open RTBs in inoperable 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> within one division division.

inoperable.

B. One or more Functions B.1 Restore one division to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> within two divisions OPERABLE status.

inoperable.

AP1000 STS 3.3.7-1 Amendment 0Rev. 0 Revision 19 Date report generated:

Friday, May 01, 2015 Page 20

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices 3.3.7 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME 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 A or B not met in MODE 1 or 2.

OR One or both Functions within three or more divisions inoperable in MODE 1 or 2.

D. Required Action and D.1 Initiate action to fully 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion insert all rods Open RTBs.

Time of Condition A or B not met in MODE 3, 4, AND or 5.

D.2 Place the Plant Control 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> OR System in a condition incapable of rod One or both Functions withdrawal.

within three or more divisions inoperable in MODE 3, 4, or 5.

AP1000 STS 3.3.7-2 Amendment 0Rev. 0 Revision 19 Date report generated:

Friday, May 01, 2015 Page 21

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices 3.3.7 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.3.7.1 -------------------------------NOTE------------------------------

This Surveillance must be performed on both reactor trip breakers associated with a single division.

Perform TADOT on both reactor trip breakers in 92 days on a one division. STAGGERED TEST BASIS AP1000 STS 3.3.7-3 Amendment 0Rev. 0 Revision 19 Date report generated:

Friday, May 01, 2015 Page 22

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices B 3.3.7 B 3.3 INSTRUMENTATION B 3.3.7 Reactor Trip System (RTS) Trip Actuation Devices BASES BACKGROUND A description of the RTS Instrumentation is provided in the Bases for LCO 3.3.1, Reactor Trip System (RTS) Instrumentation.

APPLICABLE The RTS functions to maintain compliance with the SLs during all SAFETY AOOs and mitigates the consequences of DBAs in all MODES in which ANALYSES, LCO, the RTBs are closed.

and APPLICABILITY The RTS Trip Actuation devices are required to ensure RTS Automatic and Manual Functions can provide the necessary protection.

The LCO requires OPERABILITY of four RTS divisions with two reactor trip breakers (RTB) per division, and one undervoltage and shunt trip mechanism per RTB.

The safety analyses and OPERABILITY requirements applicable to the RTS Trip Actuation Devices are discussed below:

1. Reactor Trip Breakers This trip Function applies to the RTBs exclusive of individual trip mechanisms. There are eight reactor trip breakers with two breakers in each division. The reactor trip circuit breakers are arranged in a two-out-of-four logic configuration, such that the tripping of the two circuit breakers associated with one division does not cause a reactor trip. This circuit breaker arrangement is illustrated in FSAR DCD Figure 7.1-7. The LCO requires four divisions of the Reactor Trip Switchgear to be OPERABLE with two trip breakers associated with each required division. This logic is required to meet the safety function assuming a single failure.

This trip Function must be OPERABLE in MODES 1 and or 2 when the reactor is critical. In MODES 3, 4, and or 5, this RTS trip Function must be OPERABLE when the RTBs are closed, and the Plant Control System (PLS) is capable of rod withdrawal or when one or more rods are not fully inserted.

AP1000 STS B 3.3.7-1 Amendment 0Rev. 0 Revision 19 Date report generated:

Friday, May 01, 2015 Page 23

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices B 3.3.7 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

2. Reactor Trip Breaker Undervoltage and Shunt Trip Mechanisms The LCO requires both the Undervoltage and Shunt Trip Mechanisms to be OPERABLE for each RTB that is in service. The trip mechanisms are not required to be OPERABLE for trip breakers that are open, racked out, incapable of supplying power to the PLS, or declared inoperable under Function 1 above. OPERABILITY of both trip mechanisms on each breaker ensures that no single trip mechanism failure will prevent opening the breakers on a valid signal.

This trip Function must be OPERABLE in MODES 1 and 2 when the reactor is critical. In MODES 3, 4, and 5, this RTS trip Function must be OPERABLE when the RTBs are closed, and the Plant Control System (PLS) is capable of rod withdrawal or when one or more rods are not fully inserted.

The RTS Trip Actuation Devices satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

ACTIONS A Note has been added in the ACTIONS to clarify the application of Completion Time rules. The Conditions of this Specification may be entered independently for each Function listed in LCO 3.3.7 on Table 3.3.7-1.

A.1 Condition A addresses the situation where one or both RTS Trip Actuation Device functions within one division are inoperable. With one division inoperable, the Required Action is to open the RTBs in the inoperable division within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time is considered reasonable since the protective function will still function.

B.1 Condition B addresses the situation where one or both RTS Trip Actuation Device functions within two divisions are inoperable. With two divisions inoperable, the Required Action is to restore one division to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is considered reasonable since the protective function will still function.

AP1000 STS B 3.3.7-2 Amendment 0Rev. 0 Revision 19 Date report generated:

Friday, May 01, 2015 Page 24

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices B 3.3.7 BASES ACTIONS (continued)

C.1 Condition C addresses the situation where the Required Action and associated Completion Time of Condition A or B are not met in MODE 1 or 2, or there are one or both RTS Trip Actuation Device functions within three or more divisions inoperable in MODE 1 or MODE 2.

Required Action C.1 directs that the plant must be placed in 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 Times for Required Action C.1 is reasonable, based on operating experience, to reach the specified condition from full power conditions in an orderly manner and without challenging plant systems.

D.1 and D.2 Condition D addresses the situation where the Required Action and associated Completion Time of Condition A or B are not met in MODE 3, 4, or 5, or there are one or both RTS Trip Actuation Device functions within three or more divisions inoperable in MODE 3, 4, or 5.

Required Action D.1 requires initiating action to fully insert all control rods the RTBs to be opened within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and Required Action D.2 requires that the Plant Control System be placed in a condition incapable of rod withdrawal within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The allowed Completion Times are is reasonable, based on operating experience, to reach the specified condition in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.3.7.1 REQUIREMENTS SR 3.3.7.1 is the performance of a TADOT on both reactor trip breakers associated with a single division every 92 days on a STAGGERED TEST BASIS for four divisions. This test shall verify OPERABILITY by actuation of the end devices.

The Reactor Trip Breaker (RTB) test shall include separate verification of the undervoltage and shunt trip mechanisms. Each RTB in a division shall be tested separately in order to minimize the possibility of an inadvertent trip. Both breakers in a single division are tested during each STAGGERED TEST.

AP1000 STS B 3.3.7-3 Amendment 0Rev. 0 Revision 19 Date report generated:

Friday, May 01, 2015 Page 25

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices B 3.3.7 BASES SURVEILLANCE REQUIREMENTS (continued)

The Frequency of every 92 days on a STAGGERED TEST BASIS is adequate based on industry operating experience, considering instrument reliability and operating history data. In addition, the AP1000 design provides additional breakers to enhance reliability.

The SR is modified by a Note to clarify that both breakers in a single division are to be tested during each STAGGERED TEST.

REFERENCES 1. FSAR Chapter 15.0, Accident Analysis.

AP1000 STS B 3.3.7-4 Amendment 0Rev. 0 Revision 19 Date report generated:

Friday, May 01, 2015 Page 26

GTST AP1000-O60-3.3.7, Rev. 1 XII. Applicable STS Subsection After Incorporation of this GTSTs Modifications The entire subsection of the Specifications and the Bases associated with this GTST, following incorporation of the modifications, is presented next.

Date report generated:

Friday, May 01, 2015 Page 27

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices 3.3.7 3.3 INSTRUMENTATION 3.3.7 Reactor Trip System (RTS) Trip Actuation Devices LCO 3.3.7 Four divisions of RTS trip actuation devices for the following Functions shall be OPERABLE:

a. Reactor Trip Breakers (RTBs); and
b. RTB Undervoltage and Shunt Trip Mechanisms.

APPLICABILITY: MODES 1 and 2, MODES 3, 4, and 5 with Plant Control System capable of rod withdrawal or one or more rods not fully inserted.

ACTIONS

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

Separate Condition entry is allowed for each Function.

CONDITION REQUIRED ACTION COMPLETION TIME A. One or both Functions A.1 Open RTBs in inoperable 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> within one division division.

inoperable.

B. One or more Functions B.1 Restore one division to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> within two divisions OPERABLE status.

inoperable.

AP1000 STS 3.3.7-1 Rev. 0 Date report generated:

Friday, May 01, 2015 Page 28

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices 3.3.7 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME 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 A or B not met in MODE 1 or 2.

OR One or both Functions within three or more divisions inoperable in MODE 1 or 2.

D. Required Action and D.1 Initiate action to fully insert 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion all rods.

Time of Condition A or B not met in MODE 3, 4, AND or 5.

D.2 Place the Plant Control 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> OR System in a condition incapable of rod withdrawal.

One or both Functions within three or more divisions inoperable in MODE 3, 4, or 5.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.3.7.1 Perform TADOT on both reactor trip breakers in one 92 days on a division. STAGGERED TEST BASIS AP1000 STS 3.3.7-2 Rev. 0 Date report generated:

Friday, May 01, 2015 Page 29

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices B 3.3.7 B 3.3 INSTRUMENTATION B 3.3.7 Reactor Trip System (RTS) Trip Actuation Devices BASES BACKGROUND A description of the RTS Instrumentation is provided in the Bases for LCO 3.3.1, Reactor Trip System (RTS) Instrumentation.

APPLICABLE The RTS functions to maintain compliance with the SLs during all AOOs SAFETY and mitigates the consequences of DBAs in all MODES in which the ANALYSES, LCO, RTBs are closed.

and APPLICABILITY The RTS Trip Actuation devices are required to ensure RTS Automatic and Manual Functions can provide the necessary protection.

The LCO requires OPERABILITY of four RTS divisions with two reactor trip breakers (RTB) per division, and one undervoltage and shunt trip mechanism per RTB.

The safety analyses and OPERABILITY requirements applicable to the RTS Trip Actuation Devices are discussed below:

1. Reactor Trip Breakers This trip Function applies to the RTBs exclusive of individual trip mechanisms. There are eight reactor trip breakers with two breakers in each division. The reactor trip circuit breakers are arranged in a two-out-of-four logic configuration, such that the tripping of the two circuit breakers associated with one division does not cause a reactor trip. This circuit breaker arrangement is illustrated in FSAR Figure 7.1-7. The LCO requires four divisions of the Reactor Trip Switchgear to be OPERABLE with two trip breakers associated with each required division. This logic is required to meet the safety function assuming a single failure.

This trip Function must be OPERABLE in MODES 1 and 2. In MODES 3, 4, and 5, this RTS trip Function must be OPERABLE when the Plant Control System (PLS) is capable of rod withdrawal or when one or more rods are not fully inserted.

AP1000 STS B 3.3.7-1 Rev. 0 Date report generated:

Friday, May 01, 2015 Page 30

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices B 3.3.7 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

2. Reactor Trip Breaker Undervoltage and Shunt Trip Mechanisms The LCO requires both the Undervoltage and Shunt Trip Mechanisms to be OPERABLE for each RTB that is in service. The trip mechanisms are not required to be OPERABLE for trip breakers that are open, racked out, incapable of supplying power to the PLS, or declared inoperable under Function 1 above. OPERABILITY of both trip mechanisms on each breaker ensures that no single trip mechanism failure will prevent opening the breakers on a valid signal.

This trip Function must be OPERABLE in MODES 1 and 2. In MODES 3, 4, and 5, this RTS trip Function must be OPERABLE when the Plant Control System (PLS) is capable of rod withdrawal or when one or more rods are not fully inserted.

The RTS Trip Actuation Devices satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

ACTIONS A Note has been added in the ACTIONS to clarify the application of Completion Time rules. The Conditions of this Specification may be entered independently for each Function listed in LCO 3.3.7.

A.1 Condition A addresses the situation where one or both RTS Trip Actuation Device functions within one division are inoperable. With one division inoperable, the Required Action is to open the RTBs in the inoperable division within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time is considered reasonable since the protective function will still function.

B.1 Condition B addresses the situation where one or both RTS Trip Actuation Device functions within two divisions are inoperable. With two divisions inoperable, the Required Action is to restore one division to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is considered reasonable since the protective function will still function.

AP1000 STS B 3.3.7-2 Rev. 0 Date report generated:

Friday, May 01, 2015 Page 31

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices B 3.3.7 BASES ACTIONS (continued)

C.1 Condition C addresses the situation where the Required Action and associated Completion Time of Condition A or B are not met in MODE 1 or 2, or there are one or both RTS Trip Actuation Device functions within three or more divisions inoperable in MODE 1 or MODE 2. Required Action C.1 directs that the plant must be placed in 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 Times for Required Action C.1 is reasonable, based on operating experience, to reach the specified condition from full power conditions in an orderly manner and without challenging plant systems.

D.1 and D.2 Condition D addresses the situation where the Required Action and associated Completion Time of Condition A or B are not met in MODE 3, 4, or 5, or there are one or both RTS Trip Actuation Device functions within three or more divisions inoperable in MODE 3, 4, or 5. Required Action D.1 requires initiating action to fully insert all control rods within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and Required Action D.2 requires that the Plant Control System be placed in a condition incapable of rod withdrawal within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the specified condition in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.3.7.1 REQUIREMENTS SR 3.3.7.1 is the performance of a TADOT on both reactor trip breakers associated with a single division every 92 days on a STAGGERED TEST BASIS for four divisions. This test shall verify OPERABILITY by actuation of the end devices.

The Reactor Trip Breaker (RTB) test shall include separate verification of the undervoltage and shunt trip mechanisms. Each RTB in a division shall be tested separately in order to minimize the possibility of an inadvertent trip. Both breakers in a single division are tested during each STAGGERED TEST.

AP1000 STS B 3.3.7-3 Rev. 0 Date report generated:

Friday, May 01, 2015 Page 32

GTST AP1000-O60-3.3.7, Rev. 1 RTS Trip Actuation Devices B 3.3.7 BASES SURVEILLANCE REQUIREMENTS (continued)

The Frequency of every 92 days on a STAGGERED TEST BASIS is adequate based on industry operating experience, considering instrument reliability and operating history data. In addition, the design provides additional breakers to enhance reliability.

REFERENCES 1. FSAR Chapter 15.0, Accident Analysis.

AP1000 STS B 3.3.7-4 Rev. 0 Date report generated:

Friday, May 01, 2015 Page 33

Retrieved from "https://kanterella.com/w/index.php?title=ML22240A042&oldid=3470183"