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#REDIRECT [[1CAN101701, License Amendment Request Revision to Technical Specification Bases Related to Emergency Feedwater Turbine-Driven Pump Steam Supply Valves]]
| number = ML17275A910
| issue date = 10/02/2017
| title = Arkansas Nuclear One, Unit 1, License Amendment Request Revision to Technical Specification Bases Related to Emergency Feedwater Turbine-Driven Pump Steam Supply Valves
| author name = Anderson R L
| author affiliation = Entergy Operations, Inc
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000313
| license number = DPR-051
| contact person =
| case reference number = 1CAN101701
| document type = Letter, License-Application for Facility Operating License (Amend/Renewal) DKT 50
| page count = 21
}}
 
=Text=
{{#Wiki_filter:
10 CFR 50.90 1CAN101701 October 2, 2017
 
ATTN:  Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC  20555
 
==SUBJECT:==
License Amendment Request Revision to Technical Specification Bases related to Emergency Feedwater Turbine-Driven Pump Steam Supply Valves Arkansas Nuclear One, Unit 1 Docket No. 50-313 License No. DPR-51  Pursuant to 10 CFR 50.90, Entergy Operations, Inc. (Entergy), hereby requests NRC approval of a proposed change to the Arkansas Nuclear One, Unit 1 (ANO-1) Technical Specification (TS) 3.7.5, "Emergency Feedwater (EFW) System," Bases. The change would stipulate the conditions in which the TS 3.7.5, Condition A, 7-day Completion Time should apply to the ANO-1 turbine-driven EFW pump steam supply valves. The proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c).
 
The Enclosure provides a description and assessment of the proposed change. Attachment 1 of the enclosure provides the existing TS Bases page marked to show the proposed change. provides the revised (clean) TS Bases page. Approval of the proposed amendment is requested by November 1, 2018. Once approved, the amendment shall be implemented within 60 days. Note that due to the absence of historical docketed information related to the DC-powered ANO-1 turbine-driven EFW pump steam supply valves, Entergy is currently applying a 72-hour Completion Time to these valves in accordance with TS 3.7.5, Condition B. Unexpected inoperability of one or more DC-powered steam supply valves during the NRC review period relevant to this proposed amendment may result in a request for enforcement discretion, depending on the circumstances related to the subject inoperability.
 
No new regulatory commitments are included in this amendment request. In accordance with 10 CFR 50.91, Entergy is notifying the State of Arkansas of this amendment request by transmitting a copy of this letter and enclosure to the designated State Official.
Entergy Operations, Inc. 1448 S.R. 333 Russellville, AR  72802 Tel  479-858-3110 Richard L. Anderson ANO Site Vice President 1CAN101701 Page 2 of 2 If there are any questions or if additional information is needed, please contact Stephenie Pyle at 479-858-4704.
 
I declare under penalty of perjury that the foregoing is true and correct.
Executed on October 2, 2017. Sincerely,
 
ORIGINAL SIGNED BY RICHARD L. ANDERSON RLA/dbb
 
==Enclosure:==
Evaluation of the Proposed Change 
 
cc: Mr. Kriss Kennedy Regional Administrator U. S. Nuclear Regulatory Commission RGN-IV 1600 East Lamar Boulevard Arlington, TX  76011-4511  NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR  72847  U. S. Nuclear Regulatory Commission Attn: Mr. Thomas Wengert MS O-08B1 One White Flint North 11555 Rockville Pike Rockville, MD  20852  Mr. Bernard R. Bevill Arkansas Department of Health Radiation Control Section 4815 West Markham Street Slot #30 Little Rock, AR  72205 Enclosure to  1CAN101701  Evaluation of the Proposed Change Enclosure to 1CAN101701 Page 1 of 14    EVALUATION OF THE PROPOSED CHANGE  1.0 SUMMARY DESCRIPTION  The proposed amendment would modify Technical Specification (TS) Bases associated with Arkansas Nuclear One, Unit 1 (ANO-1) Renewed Operating License DPR-51 to stipulate the ANO-1 turbine-driven Emergency Feedwater (EFW) pump steam supply valves in which the TS 3.7.5, Condition A, 7-day Completion Time, should apply. While the subject 7-day Completion Time is known to apply to the AC-powered turbine driven EFW pump steam supply valves, it is unclear whether the 7-day Completion Time can be applied to the associated DC-powered steam supply valves. Because historical correspondence does not clearly stipulate the inclusion of the DC-powered steam supply valves in application of the 7-day Completion Time, Entergy requests NRC review and approval of an amendment to the subject TS Bases which will clearly indicate applicability of the 7-day Completion Time to all four turbine-driven EFW pump steam supply valves, regardless of power supply.
 
2.0 DETAILED DESCRIPTION 2.1 System Design and Operation  EFW is supplied to the two ANO-1 Steam Generators (SGs) when either the Main Feedwater (MFW) pumps or the Reactor Coolant Pumps (RCPs) are not available. The ANO-1 EFW system consists of two, full capacity, independent trains, one containing a turbine-driven pump (P-7A) and the other an electric-driven pump (P-7B). P-7B is supported by 4160 VAC vital power backed by an Emergency Diesel Generator (EDG) and is considered a "red AC" train, although there are DC interfaces. Conversely, P-7A is supplied steam from either or both SGs and is considered a "green DC" train, although there are red train DC interfaces and AC interfaces. Each pump has the flow capacity to remove heat load equal to 31/2 percent full power. The total required feedwater can be supplied to either SG from either pump. EFW flow is supplied to the SGs through piping independent of the MFW piping and via a separate feed ring located near the top of each SG. EFW flow is supplied from each pump to each SG. There are two valves in each line automatically operated by the Emergency Feedwater Initiation and Control (EFIC) system. The first valve in each line is a DC solenoid operated, modulating valve used for flow control. The second valve is a motor operated valve (MOV) used for EFW isolation to a faulted SG. An EFIC signal will result in full actuation of both EFW trains.
 
EFIC inputs include low SG level, low SG pressure (to isolate a faulted SG), loss of both MFW pumps, loss of all RCPs, receipt of an Engineered Safeguards Actuation System (ESAS) signal, and signals from the Automatic Trip Without Scram (ATWS) circuitry. Because the proposed amendment request is limited to the P-7A steam supply portion of the system, further detail of other EFW system operations is not included herein. However, additional detail of the actuation aspects and design of the EFW system is included in the ANO-1 Safety Analysis Report (SAR), Section 7.1.4 (EFIC), Section 10.4.8 (EFW), and Chapter 14 (accident analyses). A simplified schematic of the EFW system, with focus on the steam supply portion of the system, is provided below.
 
Enclosure to 1CAN101701 Page 2 of 14     
 
As illustrated above, the system alignment (i.e., valve positions - normally open or normally closed), power supply type (DC or AC), and power supply trains ensure that EFW can be provided to, or isolated from, the SGs assuming a single failure of any component or power source. The flow control and isolation valves are normally open and DC solenoid valves fail open upon loss of power.
With respect to the P-7A steam supply, the AC-powered MOVs are maintained open because the ANO-1 EFW system was designed to ensure EFW flow upon a loss of all onsite AC power. However, these valves do receive an EFIC open signal. Upon EFIC actuation, the normally open AC-powered MOVs and the normally closed DC-powered Bypass MOVs receive an open signal. The flow orifice in the bypass line limits the initial steam flow to the P-7A turbine, allowing time for the turbine governor to take control of pump speed prior to the main DC-powered steam supply valves opening (i.e., prevents a potential overspeed event). The main DC-powered steam supply MOVs receive an open signal ~15 seconds following initial EFIC actuation, and upon reaching ~90% open, the EFW turbine speed ramps upward to ~3600 rpm to support full flow requirements. Red DC Red DCGreen DC (Bypass) EFICM Red DCSG "A" P-7A P-7B EFW PUMPSLoop 1        Service Water M M Loop 2        Service Water M M Condensate Storage Tanks SSM MSM SRed DC Green DC Green DCGreen ACGreen AC SG "B" Red DC (Bypass) EFIC CV-2665EFIC      CV-2613 CV-2615Main Steam #1Red AC CV-2667 EFIC MMain Steam #2 Green AC CV-2617 EFIC M M MRed DC CV-2663 EFIC M M Green DCSteam Trap Enclosure to 1CAN101701 Page 3 of 14    Other Feedwater Sources  A non-vital powered, 5% full power capacity, motor-driven Auxiliary Feedwater (AFW) pump is connected in parallel with the MFW pumps which is normally used during plant heatup, startup, and cooldown operations (ANO-1 SAR Section 10.4.7). A non-vital powered Common Feedwater (CFW) pump has recently been installed although will not be operational for ANO-1 until startup from the upcoming spring 2018 refueling outage. The CFW system provides a non-safety related backup source of water to either or both SGs on either ANO-1 or ANO, Unit 2 (ANO-2), in the event that the EFW system is not available during certain fire scenarios. Further information related to the CFW system is available in Section 10.4.11 of the ANO-2 SAR. 
 
2.2 Current TS Requirements  The ANO-1 TSs were converted to the improved TSs (ITS) in 2001, consistent with Revision 1 of NUREG 1430, "Standard Technical Specifications for Babcock & Wilcox Plants."  The current ITS version available is Revision 4 of NUREG 1430. ANO-1 has not yet adopted Technical Specification Task Force (TSTF) 412, "Provide Actions for One Steam Supply to Turbine Driven AFW/EFW Pump Inoperable," Revision 3. TSTF-412 included changes that addressed inoperability of a steam supply path to the turbine driven EFW pump coincident with inoperability of the electric driven pump. ANO-1 has applied for adoption of TSTF-412 in Reference 3. Absent TSTF-412, the ANO-1 EFW TS is otherwise consistent with NUREG 1430 and is included below.
 
Note that the proposed EFW TS Bases change subject to this amendment request, as described in Section 2.4 below, will not create a conflict with the Reference 3 request to adopt TSTF-412, currently under NRC review.
CONDITION REQUIRED ACTION COMPLETION TIME A. One steam supply to turbine driven EFW pump inoperable. OR  --------------NOTE------------ Only applicable if MODE 2 has not been entered following refueling.
----------------------------------  Turbine driven EFW pump inoperable in MODE 3 following refueling. A.1 Restore affected equipment to OPERABLE status. 7 days  AND 10 days from discovery of failure to meet the LCO (continued next page)
Enclosure to 1CAN101701 Page 4 of 14    CONDITION REQUIRED ACTION COMPLETION TIME B. One EFW train inoperable for reasons other than Condition A in MODE 1, 2, or 3. B.1 Restore EFW train to OPERABLE status. 72 hours AND  10 days from discovery of failure to meet the LCO  C. Required Action and associated Completion Time of Condition A or B not met. C.1 Be in MODE 3. AND C.2 Be in MODE 4.
6 hours 
 
18 hours
 
D. Two EFW trains inoperable in MODE 1, 2, or 3. D.1 -------------NOTE---------------- LCO 3.0.3 and all other LCO Required Actions requiring MODE changes are suspended until one EFW train is restored to OPERABLE status. -----------------------------------  Initiate action to restore one EFW train to OPERABLE status. 
 
Immediately E. Required EFW train inoperable in MODE 4. E.1 Initiate action to restore EFW train to OPERABLE status. Immediately The associated TS Bases relevant to the steam supply portion of the ANO-1 EFW system and subject to this amendment request are included below. Emphasis is added where appropriate.
The turbine driven EFW pump receives steam from either of the two main steam headers, upstream of the main steam isolation valves (MSIVs). For both EFW trains to be considered OPERABLE, the components and flow paths are required to be capable of providing EFW flow to both steam generators. This requires that the turbine driven EFW pump be OPERABLE with two steam supplies (one from each of the main steam lines upstream of the MSIVs) and capable of supplying EFW flow to the steam generators.
Enclosure to 1CAN101701 Page 5 of 14    (Required Action A.1)  With one of the two steam supplies to the turbine driven EFW pump inoperable, or if the turbine driven EFW pump is inoperable in MODE 3 immediately following refueling, action must be taken to restore the steam supply to OPERABLE status within 7 days. The 7-day Completion Time is reasonable, based on the following reasons:  a. For the inoperability of a steam supply to the turbine driven EFW pump, the 7-day Completion Time is reasonable since there is a redundant steam line for the turbine driven pump. b. For the inoperability of the turbine driven EFW pump while in MODE 3 immediately subsequent to a refueling, the 7-day Completion Time is reasonable due to the minimal decay heat levels in this situation. c. For both the inoperability of a steam supply line to the turbine driven pump and an inoperable turbine driven EFW pump while in MODE 3 immediately following a refueling, the 7-day Completion Time is reasonable due to the availability of the redundant OPERABLE motor driven EFW pump; and due to the low probability of an event requiring the use of the turbine driven EFW pump. Condition A is modified by a Note which limits the applicability of the Condition to when the unit has not entered MODE 2 following a refueling. Condition A allows one EFW train to be inoperable for 7 days vice the 72-hour Completion Time in Condition B. This longer Completion Time is based on the reduced decay heat following refueling and prior to the reactor being critical.  (Required Action B.1)  This Condition includes the loss of two steam supply lines to the turbine driven EFW pump.
2.3 Reason for the Proposed Change  The TS and TS Bases excerpts in Section 2.2 above focus on steam "lines" or supplies, and do not differentiate between the AC-powered and DC-powered steam supply MOVs. ANO recently polled other pressurized water reactor (PWR) plants to determine if the ANO-1 EFW steam supply design was similar to another plant. Responses received did not identify a like design.
In general, plants were designed with valves similar to the ANO-1 AC-powered steam supply MOVs which joined into a common line containing a single valve and bypass valve arrangement prior to steam reaching the EFW turbine governor. As illustrated above, ANO-1 has dual (parallel) valves and bypass valves prior to steam reaching the P-7A turbine governor.
In addition, historical correspondence did not include sufficient detail to determine if the NRC had specifically reviewed the ANO-1 design when the 7-day Completion Time for one inoperable steam supply path was adopted into the TSs (additional detail in Section 3.0 below).
Because of the apparent unique design of the ANO-1 EFW turbine steam supply and the lack of historical evidence related to NRC review of this design against the subject 7-day Completion Time, Entergy requests NRC approval of a change to the respective TS Bases, clarifying the applicability of the 7-day Completion Time to any combination of ANO-1 EFW steam supply valve inoperabilities, provided at least one steam path remains available at all times.
Enclosure to 1CAN101701 Page 6 of 14    2.4 Description of the Proposed Change  The following change to the EFW TS 3.7.5 Bases is proposed (associated with Required Action A.1):  With one of the two steam supply pathies to the turbine driven EFW pump inoperable, or if the turbine driven EFW pump is inoperable in MODE 3 immediately following refueling, action must be taken to restore the steam supply to OPERABLE status within 7 days. An OPERABLE steam supply path must include an OPERABLE AC-powered steam supply valve (CV-2617 or CV-2667), an OPERABLE DC-powered steam supply valve (CV-2613 or CV-2663), and an OPERABLE DC-powered steam supply bypass valve (CV-2615 or CV-2665). The 7-day Completion Time is reasonable, based on the following reasons: 
 
==3.0 TECHNICAL EVALUATION==
History The 7-day Completion Time of TS 3.7.5, Required Action A.1, has historically been applied to the two AC-powered MOVs located at the ANO-1 Main Steam (MS) headers where the piping exits the Reactor Building (see above drawing). However, Entergy believes this Completion Time is also applicable to the two parallel DC-powered MOVs, and the associated MOV DC-powered bypass valves, located near the turbine-driven EFW pump P-7A.
NUREG 1430, "Standard Technical Specifications Babcock and Wilcox Plants," Revision 1, was adopted and approved for ANO-1 in 2001. Prior to conversion to the improved TSs (ITS), ANO-1 had adopted a 7-day Completion Time for a condition when one of the two steam supply paths to EFW pump P-7A is inoperable. If either EFW pump is otherwise inoperable, the standard 72-hour Completion Time would remain in effect. In Entergy letter to the NRC dated June 22, 1994 (original letter requesting various changes to the EFW TS of the time), the changes were proposed in accordance with Revision 0 of NUREG 1430 (September 1992). The following is the discussion provided in the subject letter (Reference 1). Note that TS reference numbers are pre-ITS numbering.
The turbine-driven EFW pump is powered by steam from either steam generator, upstream of the main steam line isolation valves. A new action (TS 3.4.4.2) has been incorporated which allows one steam generator supply path to the turbine-driven EFW pump to be inoperable for 7 days. This condition was not previously specified in the ANO-1 TSs and results in a clarification of the operability requirements of the EFW system. The changes revising the Limiting Conditions for Operation also incorporate an Allowable Outage Time for the turbine-driven EFW pump steam supply valves which was not previously specified. The 7 day AOT is reasonable based on:
1. The redundant steam supply (from the opposite steam generator) to the turbine-driven EFW pump is operable, Enclosure to 1CAN101701 Page 7 of 14    2. The motor-driven EFW pump is operable, and  3. The probability of an event occurring that would require the inoperable steam supply valve to actuate is relatively low. The "probability" reference was qualitative in nature; no quantitative evaluation was performed in the development of the subject 7-day Completion Time when it was included in Revision 0 of NUREG 1430.
No further discussion or drawing of the ANO-1 EFW steam supply system was included in the Reference 1 letter. No Requests for Additional Information were issued in relation to the subject amendment request. The changes to the respective EFW TS Bases supporting this TS amendment with respect to the 7-day Completion Time included the justification above. In addition, the following statement was added to the TS Bases to clarify P-7A operability requirements (associated with the Limiting Condition for Operation at the time, not the 7-day Completion Time):
This requires that the turbine driven EFW pump be operable with redundant steam supplies from each of the main steam lines upstream of the MSIVs (CV-2617 and CV-2667) and capable of supplying EFW flow to either of the two steam generators. The two valves listed in the TS Bases refer to the AC-powered MOVs in the drop legs from the respective MS headers (discussed in detail in Section 2.0 above). Again, the design and function of these valves, or a description of the remaining portions of the EFW steam supply system, were not discussed in the body of the Reference 1 letter. Note, however, that the EFW system was originally a manually-initiated system and underwent substantial modification in 1980-1981 as a post-Three Mile Island (TMI) action. During this period, several meetings and significant correspondence between the NRC and ANO personnel occurred, resulting in eventual NRC approval of the upgraded "automated" ANO-1 EFW system. Therefore, the current ANO-1 design of the EFW system had been previously reviewed by the NRC, although not with respect to the acceptability of the proposed 7-day Completion Time for one EFW steam supply path inoperability.
The NRC approved the Reference 1 amendment request by letter dated March 1, 1995 (Reference 2). The following is discussion included in the NRC Safety Evaluation Report (SER) with respect to the subject 7-day Completion Time (emphasis added). The turbine-driven EFW pump is powered by steam from upstream of the main steam isolation valve of either steam generator. The motor-driven EFW pump is powered from a 4160v engineered safety bus backed by an emergency diesel generator. The staff finds that this proposed change which allows one steam generator supply path to the turbine-driven EFW pump to be inoperable for 7 days results in a new action not specified in the current ANO-1 TSs and is a clarification of the operability requirements of the EFW system, and is more restrictive than the current TS requirement. Therefore, the staff finds this proposed TS change acceptable.
The SER contained no specific discussion of the P-7A steam supply system design or operation.
 
Enclosure to 1CAN101701 Page 8 of 14    The three bullets incorporated in the TS Bases at the time were revised to address the Mode 3 aspects of TS 3.7.5, Condition A, during the conversion to ITS as follows:
With one of the two steam supplies to the turbine driven EFW pump inoperable, or if the turbine driven EFW pump is inoperable in MODE 3 immediately following refueling, action must be taken to restore the steam supply to OPERABLE status within 7 days. The 7-day Completion Time is reasonable, based on the following reasons:  a. For the inoperability of a steam supply to the turbine driven EFW pump, the 7-day Completion Time is reasonable since there is a redundant steam line for the turbine driven pump. b. For the inoperability of the turbine driven EFW pump while in MODE 3 immediately subsequent to a refueling, the 7-day Completion Time is reasonable due to the minimal decay heat levels in this situation. c. For both the inoperability of a steam supply line to the turbine driven pump and an inoperable turbine driven EFW pump while in MODE 3 immediately following a refueling, the 7-day Completion Time is reasonable due to the availability of the redundant OPERABLE motor driven EFW pump; and due to the low probability of an event requiring the use of the turbine driven EFW pump. The P-7A operability statement added to the EFW TS Bases related to the Reference 2 TS amendment was also revised during conversion to ITS for consistency with NUREG 1430, Revision 1 (i.e., specific valve references removed):  This requires that the turbine driven EFW pump be OPERABLE with two steam supplies (one from each of the main steam lines upstream of the MSIVs) and capable of supplying EFW flow to the steam generators. Acceptability of Proposed Change  TS actions provide a relatively short time interval to recover inoperable equipment in order to avoid the potentially unnecessary risks and challenges to plant systems associated with a shutdown of the unit. The time intervals (or Completion Times) permitted for recovery take into account the fact that if a single failure of a component redundant to the inoperable component were to occur at the onset of an accident, the respective safety function would likely not be met.
As discussed above, conditions involving the inoperability of one of the two steam paths to the turbine-driven EFW pump are limited to 7 days. During this period, any accident, coupled with a single active failure, will not prevent EFW from providing feed flow to the SGs, although automatic features may be affected. Note, however, that a single failure is not assumed to occur when in compliance with a TS Action.
Entergy has determined that, regardless of the combination of valves in the ANO-1 EFW steam supply path which may be inoperable at a given time, the EFW system remains capable of fulfilling its safety function assuming a single active failure following the onset of an accident, provided at least one steam path is maintained available, except in two unique cases (described later). In most cases, whether AC-powered or DC-powered steam supply path valves are affected (or both), the bases for the previously approved 7-day Completion Time is supported Enclosure to 1CAN101701 Page 9 of 14    and may be applied accordingly. The following table illustrates the various single failures and accidents of interest in order to substantiate this conclusion. The accidents of interest are those for which the EFW was designed to mitigate:  1) Loss of Offsite Power (LOOP), 2) Loss of All AC Power (LOAC), 3) Main Feedwater Line Break (MFLB), 4) Main Steam Line Break (MSLB), and 5) Small Break Loss of Coolant Accident (SBLOCA). EFW is not specifically credited in the ANO-1 accident analysis of a Steam Generator Tube Rupture (SGTR) because a LOOP is not assumed concurrent with a SGTR. Absent a LOOP, Main and Auxiliary Feedwater is used to feed the unaffected SG as desired.
The following assessment assumes one AC-powered MOV, one DC-powered MOV, and one DC-powered Bypass MOV are inoperable (cross-train inoperability does not impact results except on EFIC failures). Hot shorts are also not considered since an accident is not assumed coincident with a fire. For completeness, the SGTR accident is also assessed below.
Single Failure Accident EFW Response Remaining AC-powered steam MOV LOOP, SBLOCA EFW function is met by motor-driven AC train via power from red train EDG. Because AC-powered MOV is normally open, P-7A remains available. Remaining AC-powered steam MOV MFLB, MSLB, SGTR EFW function is met by motor-driven AC train via power from red train EDG. Because AC-powered MOV is normally open, P-7A may also be available, depending on the affected SG. Remaining AC-powered steam MOV LOAC Because AC-powered MOV is normally open, P-7A remains available. DC-powered steam valves are unaffected. Remaining DC-powered steam MOV and/or Bypass MOV LOOP, SGTR, SBLOCA, MSLB, MFLB EFW function is met by motor-driven AC train via power from red train EDG. Remaining DC-powered steam MOV and/or Bypass MOV LOAC Automatic EFW function is unavailable. P-7A may be started locally by manually opening DC-powered Bypass MOV, followed by a DC-powered MOV. The station blackout diesel can be started/connected to restore power to the motor-driven EFW pump. Motor-driven EFW Pump P-7B ALL EFW function is met by P-7A via remaining steam path.
Enclosure to 1CAN101701 Page 10 of 14    Single Failure Accident EFW Response EFIC Channel A OR Red Train DC ALL If the green train DC-powered MOV and Bypass MOV are inoperable, EFW will not automatically feed the SGs since EFIC Channel A actuates the red train steam MOVs and the red train motor-driven EFW pump (the motor-driven EFW pump breaker also requires red train DC control power to close). Affected steam-driven EFW components may still be manually manipulated from the Control Room following a loss of EFIC Channel A provided red train DC power remains available. On loss of red train DC power, the motor-driven pump can be started at the switchgear. EFIC Channel B OR Green Train DC ALL EFW function is met by motor-driven AC train via power from red train EDG. P-7A remains available if red train DC-powered MOV and Bypass MOV are operable. It is important to recognize that any EFW steam valve inoperability requires entry into TS 3.7.5, following which a single failure is no longer assumed while complying with the respective TS Action(s). However, the subject of this amendment request is focused on the time allotted to restore an EFW steam valve to operable status. Therefore, it is reasonable to assess potential accident consequences should a single failure occur in order to determine an appropriate Completion Time for the subject EFW components. As illustrated above, a LOAC coupled with the failure of a remaining DC-powered steam MOV or Bypass MOV will prevent automatic start of the EFW system (local manual operation remains available). However, ANO has additional power sources that can be manually connected in the event of a loss of both EDGs coincident with a LOOP:  1) the station blackout diesel generator, and 2) a portable diesel generator (part of the station flexible and diverse coping strategy, or FLEX).
 
In relation to 10 CFR 50.63(c)(2), "Loss of All Alternating Current Power," specifically Part 50.63(c)(2), ANO is committed to starting and connecting the station blackout diesel (Alternate AC Diesel Generator) within 10 minutes of a LOAC. This action can be performed from the Control Room and provides power to the motor-driven EFW pump. In relation to EFW, the use of the station blackout power source would only be initially necessary during a LOAC if a single failure of the remaining DC-powered steam valve(s) occurred.
 
The remaining failure mode that could prevent automatic EFW function is the loss of all red train DC power or the loss of EFIC Channel A, assuming green train DC-powered steam MOVs were initially inoperable. The redundant red train DC-powered steam MOVs require red train DC power to operate and receive an open signal from EFIC Channel A only.
 
As discussed above, the DC-powered EFW steam MOVs present two potentials for defeating the automatic function of the EFW system which are not experienced during scenarios involving the AC-powered EFW steam MOVs. In one case, the accident must be a LOAC and must include a single failure of at least one operable DC-powered EFW steam MOV. In the remaining case, the green train DC-powered MOV(s) must be initially inoperable followed by a Enclosure to 1CAN101701 Page 11 of 14    single failure of a specific EFIC channel or specific vital DC train. The initial NRC approval of the 7-day Completion Time for an inoperable EFW steam path was based, in part, on the unquantified, but reasonably low probability of an event requiring the use of the turbine-driven EFW pump during the 7-day period. Given the specific failures and or accident scenarios required to defeat the automatic function of the EFW when DC-powered steam MOVs are inoperable and the ability to recover EFW in a relatively short period of time by use of the Alternate AC Diesel Generator (AACDG) or manual operation of EFW components, Entergy believes the 7-day Completion Time currently provided in TS 3.7.5 should apply to the DC-powered EFW steam MOVs. As discussed previously, additional defense-in-depth exists via the AFW pump, utilized during plant heatup, cooldown, and startup (up to 5% full power). Similar to the recovery of the motor-driven EFW pump during a LOAC, power to the AFW pump is also restored when the AACDG is connected to the associated 4160 VAC bus. In addition, ANO-1 is currently in transition to National Fire Protection Association (NFPA) 805 with respect to its fire protection requirements and programs. The transition includes a new CFW pump, capable of supply SGs on either ANO unit. This pump is currently operational for ANO-2 and is required to be operational for ANO-1 prior to startup from the next ANO-1 refueling outage (spring 2018). The CFW pump is also restored and can be used, if needed, following a LOAC via the AACDG power source and can be powered directly from an offsite power source (London Line). These additional feedwater sources further minimize the probability of a prolonged loss of feedwater following a LOAC or any other accident involving a loss of the aforementioned automatic EFW function.
 
Summary As stated previously, the acceptability of the 7-day Completion Time when one steam supply path is inoperable was based on 1) the availability of the remaining steam supply, 2) the availability of the redundant electric-driven EFW train, and 3) the low probability of losing both the remaining steam supply and the electric-driven EFW train at the onset of an accident.
Entergy believes inclusion of the DC-powered EFW steam supply MOVs meets the acceptability conclusions of the currently approved 7-day Completion Time. Therefore, Entergy requests NRC approval of the proposed TS 3.7.5 Bases change supporting application of the 7-day Completion Time to any condition in which one steam "path" to the turbine-driven EFW pump P-7A is inoperable.
 
==4.0 REGULATORY EVALUATION==
4.1 Applicable Regulatory Requirements/Criteria Pursuant to 10 CFR 50.36(c), TS are required to include items in the following categories: (1) safety limits, limiting safety system settings, and limiting control settings, (2) limiting conditions for operation (LCOs), (3) surveillance requirements (SRs), (4) design features, and (5) administrative controls. 10 CFR 50, Appendix A, General Design Criteria (GDC) 34 and 44 state that the EFW system is required to assure (1) the capability to transfer heat loads from the reactor system to a heat sink under both normal operating and accident conditions, (2) the redundancy of components for performance of the safety function under accident conditions, assuming a single active component failure, and (3) the capability to isolate components, subsystems, or piping if required to maintain system safety function.
Enclosure to 1CAN101701 Page 12 of 14    The proposed change to the TS 3.7.5 Bases continues to support the intent of the TS rule and does not invalidate the EFW system's capability with respect to compliance with GDC 24 and 44 as stated above. Note that single failure criterion is not considered while in compliance with a TS Action statement.
4.2 Precedent While many U.S. pressurized water reactors have adopted the current 7-day Completion Time for an inoperable steam supply to the respective turbine-driven EFW pump, the ANO-1 EFW steam supply is unique in that a second set of steam supply valves powered from redundant vital DC trains is included in the system design. Therefore, no applicable precedent was identified during development of this amendment request that would directly correspond to the ANO-1 design. 4.3 No Significant Hazards Consideration Analysis Entergy Operations, Inc. (Entergy) has evaluated the proposed change to the Technical Specification (TS) Bases associated with TS 3.7.5, "Emergency Feedwater (EFW) System,"
using the criteria in 10 CFR 50.92 and has determined that the proposed change does not involve a significant hazards consideration.
Entergy proposes a change to the Arkansas Nuclear One, Unit 1 (ANO-1) TS 3.7.5 Bases that would clarify application of the current 7-day Completion Time for an inoperable turbine-driven EFW pump steam supply to any combination of steam supply path valve inoperabilities provided at least one steam supply path remains operable and available.
Basis for no significant hazards consideration determination:
 
As required by 10 CFR 50.91(a), Entergy analysis of the issue of no significant hazards consideration is presented below. 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?  Response:  No  The EFW system is not an initiator of any design basis accident or event and, therefore, the proposed change does not increase the probability of any accident previously evaluated.
The proposed change to clarify the conditions in which the current 7-day Completion Time for an inoperable steam supply path to turbine-driven EFW pump does not change the response of the plant to any accidents, since single failure criterion is not applicable when complying with associated TS Actions. The proposed change does not adversely affect accident initiators or precursors, nor alter the design assumptions, conditions, and configuration of the facility or the manner in which the plant is operated and maintained. The proposed change does not adversely affect the ability of structures, systems, and components (SSCs) to perform their intended safety function to mitigate the consequences of an initiating event within the assumed acceptance limits. The proposed change does not affect the source term, containment isolation, or Enclosure to 1CAN101701 Page 13 of 14    radiological release assumptions used in evaluating the radiological consequences of any accident previously evaluated. Further, the proposed change does not increase the types and amounts of radioactive effluent that may be released offsite, nor significantly increase individual or cumulative occupational/public radiation exposures. Therefore, this change does not involve a significant increase in the probability or consequences of an accident previously evaluated. 
: 2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?  Response:  No  The proposed change does not result in a change in the manner in which the EFW system provides plant protection. Absent a single failure (which is not assumed while in compliance with TS Actions), the EFW system will continue to supply water to the Steam Generators (SGs) to remove decay heat and other residual heat by delivering at least the minimum required flow rate to the SGs, as required. There are no design changes associated with the proposed change. The change to the associated TS Bases does not change any existing accident scenarios, nor create any new or different accident scenarios. The change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. In addition, the change clarifies the application of the current 7-day Completion Time for an inoperable steam supply path to the turbine-driven EFW pump and does not impose any new or different requirements or eliminate any existing requirements. The change does not alter assumptions made in the safety analysis. The proposed change is consistent with the safety analysis assumptions, which does not assume an EFW system single failure when complying with TS Actions, and current plant operating practice. Therefore, this change does not create the possibility of a new or different kind of accident from an accident previously evaluated. 
: 3. Does the proposed change involve a significant reduction in a margin of safety?
Response:  No  The proposed change does not alter the manner in which safety limits, limiting safety system settings, or limiting conditions for operation are determined. The safety analysis acceptance criteria are not impacted by these changes. The proposed change will not result in plant operation in a configuration outside the design basis. The associated TS will continue to limit the time in which one steam supply path to the turbine-driven EFW pump may be inoperable. Therefore, this change does not involve a significant reduction in a margin of safety.
Based upon the reasoning presented above, Entergy concludes that the requested change involves no significant hazards consideration, as set forth in 10 CFR 50.92(c), "Issuance of Amendment."
 
Enclosure to 1CAN101701 Page 14 of 14    4.4 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 Commission's 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.
 
==5.0 ENVIRONMENTAL CONSIDERATION==
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 Part 20, and 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. 
 
==6.0 REFERENCES==
1. Entergy letter dated June 22, 1994, "Technical Specification Change Request Concerning the Arkansas Nuclear One - Unit 1 Emergency Feedwater System" (TAC No. M89817) (1CAN069401) 
: 2. NRC letter dated March 1, 1995, "Issuance of Amendment No. 177 to Facility Operating License No. DPR-51 - Arkansas Nuclear One, Unit No. 1" (TAC No. M89817) (1CNA039501) (ML021280113)  3. Entergy letter dated July 17, 2017, "License Amendment Request - Application for Technical Specification Improvement to Revise Actions for One Steam Supply to Turbine Driven Emergency Feedwater Pump Inoperable using the Consolidated Line Item Improvement Process," (ML17198F072) (1CAN071701)
ATTACHMENTS 
: 1. Technical Specification Bases Page Markup 2. Retyped Technical Specification Bases Page Enclosure Attachment 1 to  1CAN101701  Technical Specification Bases Page Markup EFW System B 3.7.5  ANO-1 B 3.7.5-3 Amendment No. 215,    Rev. 22,52  APPLICABILITY (continued)
In MODE 4, the EFW system must be OPERABLE when the steam generators are relied upon for decay heat removal since EFW is the safety related source of feedwater to the steam generators. In MODE 4, the steam generators are normally used for heat removal until the DHR system is in operation.
In MODES 5 and 6, the steam generators are not used for DHR and the EFW system is not required. ACTIONS A Note prohibits the application of LCO 3.0.4.b to an inoperable EFW train when entering MODE 1. There is an increased risk associated with entering MODE 1 with EFW inoperable and the provisions of LCO 3.0.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.
 
A.1  With one of the two steam supply pathies to the turbine driven EFW pump inoperable, or if the turbine driven EFW pump is inoperable in MODE 3 immediately following refueling, action must be taken to restore the steam supply to OPERABLE status within 7 days. An OPERABLE steam supply path must include an OPERABLE AC-powered steam supply valve (CV-2617 or CV-2667), an OPERABLE DC-powered steam supply valve (CV-2613 or CV-2663), and an OPERABLE DC-powered steam supply bypass valve (CV-2615 or CV-2665). The 7-day Completion Time is reasonable, based on the following reasons:  a. For the inoperability of a steam supply to the turbine driven EFW pump, the 7-day Completion Time is reasonable since there is a redundant steam line for the turbine driven pump. b. For the inoperability of the turbine driven EFW pump while in MODE 3 immediately subsequent to a refueling, the 7-day Completion Time is reasonable due to the minimal decay heat levels in this situation. c. For both the inoperability of a steam supply line to the turbine driven pump and an inoperable turbine driven EFW pump while in MODE 3 immediately following a refueling, the 7-day Completion Time is reasonable due to the availability of the redundant OPERABLE motor driven EFW pump; and due to the low probability of an event requiring the use of the turbine driven EFW pump. The second Completion Time for Required Action A.1 establishes a limit on the maximum time allowed for any combination of required EFW components to be inoperable during any continuous failure to meet this LCO.
 
The 10-day Completion Time provides a limitation on the time allowed in this specified Condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which Conditions A and B are entered concurrently. The AND connector between 7 days and 10 days dictates that both Completion Times apply simultaneously, and the more restrictive must be met.
Enclosure Attachment 2 to  1CAN101701  Retyped Technical Specification Bases Page EFW System B 3.7.5  ANO-1 B 3.7.5-3 Amendment No. 215,    Rev. 22,52  APPLICABILITY (continued)
In MODE 4, the EFW system must be OPERABLE when the steam generators are relied upon for decay heat removal since EFW is the safety related source of feedwater to the steam generators. In MODE 4, the steam generators are normally used for heat removal until the DHR system is in operation.
In MODES 5 and 6, the steam generators are not used for DHR and the EFW system is not required. ACTIONS A Note prohibits the application of LCO 3.0.4.b to an inoperable EFW train when entering MODE 1. There is an increased risk associated with entering MODE 1 with EFW inoperable and the provisions of LCO 3.0.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.
 
A.1  With one of the two steam supply paths to the turbine driven EFW pump inoperable, or if the turbine driven EFW pump is inoperable in MODE 3 immediately following refueling, action must be taken to restore the steam supply to OPERABLE status within 7 days. An OPERABLE steam supply path must include an OPERABLE AC-powered steam supply valve (CV-2617 or CV-2667), an OPERABLE DC-powered steam supply valve (CV-2613 or CV-2663), and an OPERABLE DC-powered steam supply bypass valve (CV-2615 or CV-2665). The 7-day Completion Time is reasonable, based on the following reasons:  a. For the inoperability of a steam supply to the turbine driven EFW pump, the 7-day Completion Time is reasonable since there is a redundant steam line for the turbine driven pump. b. For the inoperability of the turbine driven EFW pump while in MODE 3 immediately subsequent to a refueling, the 7-day Completion Time is reasonable due to the minimal decay heat levels in this situation. c. For both the inoperability of a steam supply line to the turbine driven pump and an inoperable turbine driven EFW pump while in MODE 3 immediately following a refueling, the 7-day Completion Time is reasonable due to the availability of the redundant OPERABLE motor driven EFW pump; and due to the low probability of an event requiring the use of the turbine driven EFW pump. The second Completion Time for Required Action A.1 establishes a limit on the maximum time allowed for any combination of required EFW components to be inoperable during any continuous failure to meet this LCO.
 
The 10-day Completion Time provides a limitation on the time allowed in this specified Condition after discovery of failure to meet the LCO. This limit is considered reasonable for situations in which Conditions A and B are entered concurrently. The AND connector between 7 days and 10 days dictates that both Completion Times apply simultaneously, and the more restrictive must be met. 
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