Text

Draft Model Safety Evaluation of Traveler TSTF-542, Revision 2, Reactor Pressure Vessel Water Inventory Control
	ML16250A206
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Site:	Technical Specifications Task Force
Issue date:	10/06/2016
From:	Michelle Honcharik; Licensing Processes Branch (DPR)
To:	;
	Honcharik M
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ML16250A231	List: ML16175A394; ML16250A206;
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Enclosure 2 General Directions: This model SE provides the format and content to be used when preparing 1

the plant-specific SE of an LAR to adopt TSTF-542. The bolded bracketed information shows 2

text that should be filled in for the specific amendment; individual licensees would furnish 3

site-specific nomenclature or values for these bracketed items. The italicized wording provides 4

guidance on what should be included in each section and should not be included in the SE.

5 6

DRAFT MODEL SAFETY EVALUATION 7

BY THE OFFICE OF NUCLEAR REACTOR REGULATION 8

TECHNICAL SPECIFICATIONS TASK FORCE TRAVELER 9

TSTF-542, REVISION 2 10 REACTOR PRESSURE VESSEL WATER INVENTORY CONTROL 11 12

1.0 INTRODUCTION

13 14 By application dated [enter date] (Agencywide Documents Access and Management System 15 (ADAMS) Accession No. [MLXXXXXXXXX]), [name of licensee] (the licensee) requested to 16 adopt Technical Specifications Task Force (TSTF) Traveler TSTF-542, Reactor Pressure 17 Vessel Water Inventory Control, Revision 2, which changes to the technical specifications (TS) 18 for [PLANT]. Traveler TSTF-542, Revision 2, was approved by the NRC on [enter date]

19 (ADAMS Accession No. [MLXXXXXXXXX]).

20 21 The proposed changes would replace the existing requirements in the TS related to operations 22 which have the potential for draining the reactor vessel (OPDRVs) with revised TS providing an 23 alternative for Reactor Pressure Vessel Water Inventory Control (RPV WIC). These alternative 24 requirements would protect Technical Specification Safety Limit 2.1.1.3, which requires reactor 25 pressure vessel (RPV) water level to be greater than the top of the active fuel (TAF).

26 27 Choose applicable paragraphs based on information provided in the LAR:

28

[The licensee is not proposing any variations from the TS changes described in the 29 TSTF-542 or the applicable parts of the NRC staffs safety evaluation of TSTF-542.]

30 31

[The licensee is proposing the following variations from the TS changes described in the 32 TSTF-542 or the applicable parts of TSTF-542 or the NRC staffs safety evaluation.]

33 34

[The [PLANT] TS utilize different [numbering][and][titles] than the Standard Technical 35 Specifications on which TSTF-542 was based. Specifically, [describe differences between 36 the plant-specific TS numbering and/or titles and the TSTF-542 numbering and titles.]

37 These differences are administrative and do not affect the applicability of TSTF-542 to the 38

[PLANT] TS.]

39 40

[The [PLANT] TS limiting condition for operation (LCO) 3.5.2 does do not contain a Note 41 regarding realignment to the Low Pressure Coolant Injection mode. This has no effect on the 42 adoption of the TSTF-542 and is an acceptable variation.]

43 44

2.0 REGULATORY EVALUATION

1 2

2.1 TECHNICAL SPECIFICATIONS 3

4 Section IV, The Commission Policy, of the Final Policy Statement on Technical Specifications 5

Improvements for Nuclear Power Reactors (58 Federal Register 39132), dated July 22, 1993, 6

states in part:

7 8

The purpose of Technical Specifications is to impose those 9

conditions or limitations upon reactor operation necessary to 10 obviate the possibility of an abnormal situation or event giving rise 11 to an immediate threat to the public health and safety by 12 identifying those features that are of controlling importance to 13 safety and establishing on them certain conditions of operation 14 which cannot be changed without prior Commission approval.

15

[T]he Commission will also entertain requests to adopt portions of 16 the improved STS [(e.g., TSTF-542)], even if the licensee does 17 not adopt all STS improvements 18 The Commission encourages all licensees who submit Technical 19 Specification related submittals based on this Policy Statement to 20 emphasize human factors principles 21 In accordance with this Policy Statement, improved STS have 22 been developed and will be maintained for [the BWR/4 and 23 BWR/6 designs]. The Commission encourages licensees to use 24 the STS as the basis for plant-specific Technical Specifications 25

[I]t is the Commission intent that the wording and Bases of the 26 improved STS be used [] to the extent practicable.

27 28 2.2 SYSTEM DESCRIPTION 29 30 The boiling water reactor (BWR) RPV have a number of penetrations located below the TAF.

31 These penetrations provide entry for control blades, recirculation flow, and shutdown cooling.

32 Since these penetrations are below the TAF, this gives potential to drain the reactor vessel 33 water inventory and thus lose effective core cooling. The loss of water inventory and effective 34 core cooling can potentially lead to fuel cladding failure and radioactive release.

35 36 During operation in Modes 1 (Power Operation with reactor mode switch position in run), 2 37 (Startup with reactor mode switch position in refuel or startup/hot standby) and 3 (Hot Standby 38 with reactor mode switch position in shutdown), the TS for instrumentation and emergency core 39 cooling systems (ECCS) require operability of sufficient equipment to ensure large quantities of 40 water can be injected into the vessel should level decrease below the preselected value. These 41 requirements are designed to mitigate the effects of a loss-of-coolant accident (LOCA), but also 42 provide protection for other accidents and transients that involve a water inventory loss.

43 44 During BWR operation in Mode 4 (Cold Shutdown with average reactor coolant temperature 45 200 °F), and Mode 5 (Refueling with one or more reactor vessel head closure bolts less than 46 fully tensioned), the pressures and temperatures that could cause a LOCA are not present.

1 During certain phases of refueling (Mode 5) a large volume of water is available above the RPV 2

(i.e., the RPV head is removed, the water level is [23 feet] over the top of the RPV flange, and 3

[for BWR/4 plants enter the spent fuel storage pool gates are removed or for BWR/6 4

plants enter the upper containment pool is connected to the RPV].

5 6

The large volume of water available in and above the RPV (during much of the time when in 7

Mode 5) provides time for operator detection and manual operator action to stop and mitigate an 8

RPV draining event. However, typically at other times during a refueling outage, during cold 9

shutdown (Mode 4) or refueling (Mode 5), there may be a potential for significant drainage paths 10 from certain outage activities, human error, and other events when it is more likely to have some 11 normally available equipment, instrumentation, and systems inoperable due to maintenance and 12 outage activities. There may not be as much time for operator action as compared to times 13 when there are large volumes of water above the RPV.

14 15 In comparison to Modes 1, 2, and 3, with typical high temperatures and pressures (especially in 16 Modes 1 and 2), Modes 4 and 5 generally do not have the high pressure and temperature 17 considered necessary for a LOCA envisioned from a high energy pipe failure. Thus, while the 18 potential sudden loss of large volumes of water from a LOCA are not expected, operators 19 monitor for BWR RPV water level decrease from potential significant or even unexpected 20 drainage paths. These potential drainage paths in Modes 4 and 5 generally would require less 21 water replacement capability to maintain water above TAF.

22 23 To address the drain down potential during Modes 4 and 5, the current TS contain specifications 24 that are applicable during an OPDRV, or require suspension of OPDRVs if certain equipment is 25 inoperable. The term OPDRV is not specifically defined in the TS and historically has been 26 subject to inconsistent application by licensees. The changes discussed in this safety 27 evaluation (SE) are intended to resolve any ambiguity by creating a new RPV WIC TS with 28 attendant equipment operability requirements, required actions and surveillance requirements, 29 and deleting references to OPDRVs throughout the TS.

30 31 2.3 CHANGES TO THE TS 32 33 The proposed changes would (1) provide a definition of a new term, DRAIN TIME; (2) revise 34 and rename TS 3.5.2 as Reactor Pressure Vessel Water Inventory Control; (3) provide a new 35 TS 3.3.5.2, Reactor Pressure Vessel Water Inventory Control Instrumentation; and (4) delete 36 existing references to operations with the potential to drain the reactor pressure vessel 37 throughout the TS. The descriptions of the proposed changes are provided in this section.

38 39 A summary statement of the bases or reasons for such specifications, other than those covering 40 administrative controls, were also included in the application, but these bases shall not become 41 part of the technical specifications.

42 43 2.3.1 Insertion of New Definition of DRAIN TIME 44 45 The following definition of DRAIN TIME would be added to the TS Section 1.1, Definitions:

46 47 48 The DRAIN TIME is the time it would take for the water inventory 1

in and above the Reactor Pressure Vessel (RPV) to drain to the 2

top of the active fuel (TAF) seated in the RPV assuming:

3 4

a) The water inventory above the TAF is divided by the limiting 5

drain rate; 6

7 b) The limiting drain rate is the larger of the drain rate through a 8

single penetration flow path with the highest flow rate, or the 9

sum of the drain rates through multiple penetration flow paths 10 susceptible to a common mode failure (e.g., seismic event, 11 loss of normal power, single human error), for all penetration 12 flow paths below the TAF except:

13 14

1. Penetration flow paths connected to an intact closed 15 system, or isolated by manual or automatic valves are 16 locked, sealed, or otherwise secured in the closed position, 17 blank flanges, or other devices that prevent flow or reactor 18 coolant through the penetration flow paths; 19 20

2. Penetration flow paths capable of being isolated by valves 21 that will close automatically without offsite power prior to 22 the RPV water level being equal to the TAF when actuated 23 by RPV water level isolation instrumentation; or 24 25

3. Penetration flow paths with isolation devices that can be 26 closed prior to the RPV water level being equal to the TAF 27 by a dedicated operator trained in the task, who is in 28 continuous communication with the control room, is 29 stationed at the controls, and is capable of closing the 30 penetration flow path isolation device without offsite power.

31 32 c) The penetration flow paths required to be evaluated per 33 paragraph b) are assumed to open instantaneously and are 34 not subsequently isolated, and no water is assumed to be 35 subsequently added to the RPV water inventory; 36 37 d) No additional draining events occur; and 38 39 e) Realistic cross-sectional areas and drain rates are used.

40 41 A bounding DRAIN TIME may be used in lieu of a calculated 42 value.

43 44 45 2.3.2 Changes to TS Section 3.5:

46 47 2.3.2.1 Title of TS 3.5 48 49 The title of Section 3.5 is being revised from Emergency Core Cooling System (ECCS) and 1

Reactor Core Isolation Cooling System (RCIC) to Emergency Core Cooling Systems (ECCS),

2 RPV Water Inventory Control, and Reactor Core Isolation Cooling (RCIC) System.

3 4

2.3.2.2 Title of TS 3.5.2 5

6 The title of TS 3.5.2 is being revised from ECCS - Shutdown to Reactor Pressure Vessel 7

(RPV) Water Inventory Control.

8 9

2.3.2.3 LCO 3.5.2 10 11 TS limiting condition for operation (LCO) 3.5.2 currently states Two low pressure ECCS 12 injection/spray subsystems shall be OPERABLE. The LCO note currently states: One LPCI 13 subsystem may be considered OPERABLE during alignment and operation for decay heat 14 removal if capable of being manually realigned and not otherwise inoperable.

15 16 For BWR/4 plants choose:

17

[LCO 3.5.2 would be revised to state:

18 19 20 DRAIN TIME of RPV water inventory to the top of active fuel 21 (TAF) shall be 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

22 23 AND 24 25 One low pressure ECCS injection/spray subsystem shall be 26 OPERABLE.

27 28 29 The note for LCO 3.5.2 would be revised to state:

30 31 32 A Low Pressure Coolant Injection (LPCI) subsystem may be 33 considered OPERABLE during alignment and operation for 34 decay heat removal if capable of being manually realigned 35 and not otherwise inoperable.]

36 37 38 For BWR/6 plants choose:

39

[The phrase low pressure in LCO 3.5.2 is omitted because the high pressure core spray 40 system is used to satisfy this requirement.]

41 42 2.3.2.4 Applicability of TS LCO 3.5.2 43 44 For BWR/4 plants choose: [LCO 3.5.2 is currently applicable in MODE 4 and in MODE 5, 45 except with the spent fuel storage pool gates removed and water level [23 ft] over the top of 46 the reactor pressure vessel flange.]

47 48 For BWR/6 plants choose: [LCO 3.5.2 is currently applicable in Mode 4 and Mode 5 except with 1

the upper containment [cavity to dryer] pool [gate] removed and water level [22 ft 8 inches]

2 over the top of the reactor pressure vessel flange.]

3 4

The applicability would be revised to be Modes 4 and 5, with no exceptions.

5 6

2.3.2.5 Actions Table of TS 3.5.2 7

8 The existing Actions Table of TS 3.5.2 contains requirements to restore at least one train of 9

ECCS injection/spray systems to operable status if the LCO is not met.

10 11 The revised TS 3.5.2 Actions Table would provide increasingly stringent requirements on 12

[secondary] containment, [secondary] containment isolation valves, the standby gas treatment 13 system and methods for water injection as the Drain Time decreases. If the Drain Time is one 14 hour1.62037e-4 days 0.00389 hours 2.314815e-5 weeks 5.327e-6 months or less, immediate action must be taken to increase the Drain Time.

15 16 2.3.2.6 TS 3.5.2 Surveillance Requirements 17 18 TS 3.5.2 currently contains Surveillance Requirements (SRs) to verify the availability of a 19 suction source, the availability of an appropriate flow path, and proper functioning of the ECCS 20 injection/spray system pump(s).

21 22 The revised SRs would verify the Drain Time is greater than or equal to 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months and verify the 23 availability of a suction source, appropriate flow path and proper functioning of the required 24 ECCS injection/spray system pump.

25 26 The existing and proposed TS 3.5.2 Surveillances provide the option to perform the 27 Surveillances at a fixed interval or in accordance with the Surveillance Frequency Control 28 Program (SFCP), for those plants that have adopted an SFCP.

29 30 2.3.3 Changes to TS Section 3.3:

31 32 NOTE: The STS contain two versions of certain specifications in Section 3.3, Instrumentation.

33 One is applicable for licensees that have not adopted a Setpoint Control Program (the A 34 version) and the other is applicable for licensees that have adopted a Setpoint Control Program 35 (the B version). In the A version of the STS, the Allowable Value column is retained in the 36 Instrumentation Table, and the Instrumentation Table contains footnotes that provide details 37 regarding SRs. In the B version of the STS, the Allowable Value has been relocated to the 38 Setpoint Control Program, and this column does not appear in the Instrumentation Table.

39 Additionally, in the B version, the footnotes that provide details regarding SRs are not 40 necessary. Choose the A or B version below to correspond with the plant-specific TS.

41 42 2.3.3.1 Changes to TS LCOs [3.3.5.1A or 3.3.5.1B], Emergency Core Cooling System 43 (ECCS) Instrumentation ([Without or With Setpoint Control Program])

44 45 The TS LCO [3.3.5.1A or 3.3.5.1B] states that "the ECCS instrumentation for each Function in 46 Table 3.3.5.1-1, shall be OPERABLE with the applicability as stated in the table.

47 Table 3.3.5.1-1 currently contains requirements for function operability during Modes 4 and 5 48 when associated ECCS subsystem(s) are required to be operable per LCO 3.5.2, ECCS -

49 Shutdown. Throughout this table, the applicability in Modes 4 and 5 is being deleted because 1

the instrumentation requirements during shutdown are being consolidated into the new TS 2

3.3.5.2. Conforming changes are made to the Actions Table of TS LCO [3.3.5.1A or 3.3.5.1B].

3 4

2.3.3.2 Insertion of new TS [3.3.5.2A or 3.3.5.2B], Reactor Pressure Vessel (RPV) 5 Water Inventory Control Instrumentation ([Without or With Setpoint Control 6

Program])

7 8

A new TS 3.3.5.2 is proposed to provide alternative instrumentation requirements to support 9

manual initiation of the ECCS injection/spray subsystem required in new TS 3.5.2 and automatic 10 isolation of penetration flow paths that may be credited in the determination of drain time. The 11 current TS contain instrumentation requirements related to OPDRVs in four TS. These 12 requirements are being consolidated into new TS 3.3.5.2.

13 14 The existing TS 3.3.5.2, Reactor Core Isolation Cooling (RCIC) System Instrumentation, is 15 being renumbered to 3.3.5.3 in order to maintain the TS numbering conventions.

16 17 2.3.3.2.1 New TS 3.3.5.2[A or B] LCO and Applicability 18 19 The proposed LCO 3.3.5.2 states:

20 21 The RPV Water Inventory Control instrumentation for each 22 Function in Table 3.3.5.2-1 shall be OPERABLE.

23 24 The applicability states, "According to Table 3.3.5.2-1."

25 26 The following sections describe the instrumentation functions contained in the new 27 Table 3.3.5.2-1.

28 29 2.3.3.2.2 New Table 3.3.5.2-1, RPV Water Inventory Control Instrumentation 30 31 For BWR/4 choose 2.3.3.2.2.1 through 2.3.3.2.2.5:

32 33 2.3.3.2.2.1 Function 1.a, Core Spray System, Reactor Steam Dome Pressure - Low 34 (Injection Permissive) 35 Function 2.a, Low Pressure Coolant Injection (LPCI) System, Reactor Steam 36 Dome Pressure - Low (Injection Permissive) 37 38 These functions were moved from current TS 3.3.5.1, Function 1.c and Function 2.c. The 39 following changes are made:

40 41 The applicability is changed. The existing TS 3.3.5.1 applicability for these functions in 42 Modes 4 and 5 is modified by a note that limits the applicability to when the associated 43 ECCS subsystem(s) are required to be operable per LCO 3.5.2, "ECCS - Shutdown. The 44 revised applicability is Modes 4 and 5 without exception, to be consistent with the 45 applicability of new LCO 3.5.2, "RPV Water Inventory Control."

46 47 The number of required channels per function is unchanged.

48 49 In the new table, a Channel Check and Channel Functional Test are required at the existing 1

frequency. Calibration of the trip units, Channel Calibration, Logic System Functional Test, 2

and ECCS Response Time tests are no longer required in Modes 4 and 5.

3 4

In new LCO 3.3.5.2A, the Allowable Value is revised to eliminate the low pressure limit and 5

to retain the high pressure limit. The RPV pressure is well below the lower limit in Modes 4 6

and 5, so the low pressure limit is not needed.

7 8

2.3.3.2.2.2 Functions 1.b and 2.b, Core Spray and Low Pressure Coolant Injection (LPCI) 9 Systems, Core Spray and Low Pressure Coolant Injection Pumps Discharge 10 Flow - Low (Bypass) 11 12 These functions were moved from current TS 3.3.5.1, Function 1.d and Function 2.g. The 13 following changes are made:

14 15 The applicability is changed. The current TS 3.3.5.1 applicability for these functions in 16 Modes 4 and 5 is modified by a note that limits the applicability to when the associated 17 ECCS subsystem(s) are required to be operable per current LCO 3.5.2, "ECCS -

18 Shutdown. The revised applicability is Modes 4 and 5 without exception, to be consistent 19 with the applicability of new LCO 3.5.2, "RPV Water Inventory Control."

20 21 The number of required channels per function is changed from [2] or [4] or [1 per pump], to 22

[1 per pump] and is modified by a note stating "Associated with an ECCS subsystem 23 required to be OPERABLE by LCO 3.5.2, 'Reactor Pressure Vessel Water Inventory 24 Control.'"

25 26 In the new table, a Channel Check and Channel Functional Test are required at the existing 27 frequency. A Channel Calibration and Logic System Functional Test are no longer required 28 in Modes 4 and 5.

29 30 In new LCO 3.3.5.2A, the allowable value is unchanged.

31 32 2.3.3.2.2.3 Function 1.c, Core Spray System, Manual Initiation, and 33 Function 2.c, Low Pressure Coolant Injection (LPCI) System, Manual Initiation 34 35 These functions were moved from current TS 3.3.5.1, Function 1.e and Function 2.h. The 36 following changes are made:

37 38 The applicability is changed. The current TS 3.3.5.1 applicability for these functions in 39 Modes 4 and 5 is modified by a note that limits the applicability to when the associated 40 ECCS subsystem(s) are required to be operable per current LCO 3.5.2, "ECCS -

41 Shutdown. The revised applicability is Modes 4 and 5 without exception, to be consistent 42 with the applicability of new LCO 3.5.2, "RPV Water Inventory Control.

43 44 The number of required channels per function is changed from [2, or 1 per subsystem,] to 45

[1 per subsystem] and is modified by a note stating "Associated with an ECCS subsystem 46 required to be OPERABLE by LCO 3.5.2, 'Reactor Pressure Vessel Water Inventory 47 Control.' New LCO 3.5.2 only requires a single ECCS subsystem and the change in 1

required channels reflects that requirement.

2 3

Both the existing TS 3.3.5.1 and the revised TS 3.3.5.2 require a Logic System Functional 4

Test on this function at the same frequency.

5 6

There is no allowable value for this function.

7 8

2.3.3.2.2.4 Function 3.a, RHR System Isolation, Reactor Vessel Water Level - Low, Level 3 9

10 This function was moved from current TS 3.3.6.1, Function 6.b. The following changes are 11 made:

12 13 The function name is changed from "Shutdown Cooling System Isolation Reactor Vessel 14 Water Level - Low, Level 3" to "Residual Heat Removal [RHR] System Isolation Reactor 15 Vessel Water Level - Low, Level 3. The current title is a misnomer in the TSs as the 16 Level 3 instruments isolate more than shutdown cooling isolation valves.

17 18 The applicability is changed. The existing TS 3.3.6.1 applicability for this function in 19 Modes 4 and 5 is being deleted. The revised applicability is "when automatic isolation of the 20 associated penetration flow path is credited in calculating Drain Time."

21 22 The number of required channels is changed from [2], with a column header that states 23 "Required Channels per Trip System," to [2 in one trip system]. This retains the 24 requirement that the two channels must be associated with the same trip system.

25 26 In the new table, a Channel Check and Channel Functional Test are required at the existing 27 frequency. A calibration of the trip unit, Channel Calibration, and Logic System Functional 28 Test are no longer required in Modes 4 and 5.

29 30 The allowable value is unchanged.

31 32 2.3.3.2.2.5 Function 4.a, Reactor Water Cleanup (RWCU) System Isolation, Reactor Vessel 33 Water Level - Low Low, Level 2 34 35 This function exists in the current TS 3.3.6.1, Function 5.e. The function is inserted into new 36 STS 3.3.5.2 as follows:

37 38 The current TS 3.3.6.1 applicability for this function is Modes 1, 2, and 3. The applicability in 39 STS 3.3.5.2 is "when automatic isolation of the associated penetration flow path is credited 40 in calculating Drain Time. In other words, if the drain time calculation assumes the RWCU 41 system will be automatically isolated, this function must be operable to perform that function.

42 This is consistent with the definition of drain time and the TS 3.5.2 requirements.

43 44 The number of required channels is changed from [2], with a column header that states 45 "Required Channels per Trip System," to [2 in one trip system]. This retains the 46 requirement that the two channels must be associated with the same trip system. Only one 47 trip system is required to ensure that automatic isolation of one of the two isolation valves 1

will occur on low reactor vessel water level.

2 3

A Channel Check and Channel Functional Test are required at the existing frequency. A 4

calibration of the trip unit, Channel Calibration, Logic System Functional Test, and Isolation 5

System Response Time tests are no longer required in Modes 4 and 5.

6 7

The allowable value is unchanged.

8 9

For BWR/6 choose 2.3.3.2.2.1 through 2.3.3.2.2.9:

10 11 2.3.3.2.2.1 Function 1.a, Low Pressure Coolant Injection-A (LPCI) and Low Pressure Core 12 Spray (LPCS) Subsystems, Reactor Steam Dome Pressure - Low (Injection 13 Permissive), and 14 Function 2.a, LPCI B and LPCI C Subsystems, Reactor Steam Dome Pressure -

15 Low (Injection Permissive) 16 17 These functions were moved from current TS 3.3.5.1, Function 1.d and Function 2.d. The 18 following changes are made:

19 20 The applicability is changed. The current TS 3.3.5.1 applicability for these functions in 21 Modes 4 and 5 is modified by a note that limits the applicability to when the associated 22 ECCS subsystem(s) are required to be operable per current LCO 3.5.2, "ECCS -

23 Shutdown. The revised applicability is Modes 4 and 5 without exception, to be consistent 24 with the applicability of new LCO 3.5.2, "RPV Water Inventory Control.

25 26 In the new table, the number of required channels per function remains [3] and is modified 27 by a note stating "Associated with an ECCS subsystem required to be OPERABLE by 28 LCO 3.5.2, 'Reactor Pressure Vessel Water Inventory Control.' New TS 3.5.2 only requires 29 a single ECCS subsystem to be operable and the change reflects that requirement.

30 31 A Channel Check and Channel Functional Test are required at the existing frequency.

32 Calibration of the trip units, Channel Calibration, Logic System Functional Test, and ECCS 33 Response Time tests are no longer required in Modes 4 and 5.

34 35 In new LCO 3.3.5.2A, the allowable value is revised to eliminate the low pressure limit and 36 to retain the high pressure limit.

37 38 2.3.3.2.2.2 Functions 1.b and 1.c, Low Pressure Coolant Injection-A (LPCI) and Low 39 Pressure Core Spray (LPCS) Subsystems, LPCS Pump Discharge Flow - Low 40 (Bypass) and LPCI Pump A Discharge Flow - Low (Bypass), and 41 Function 2.b, LPCI B and LPCI C Subsystems, LPCI Pump B and LPCI Pump C 42 Discharge Flow - Low (Bypass) 43 44 These functions were moved from current TS 3.3.5.1, Function 1.e, 1.f, and 2.e. The following 45 changes are made:

46 47 The applicability is changed. The current TS 3.3.5.1 applicability for these functions is 1

Modes 4 and 5 when the associated ECCS subsystem(s) are required to be operable per 2

LCO 3.5.2, "ECCS - Shutdown. The revised Applicability is Modes 4 and 5 without 3

exception, to be consistent with the Applicability of new LCO 3.5.2, "RPV Water Inventory 4

Control."

5 6

The number of required channels per function is changed from [1] to [1 per pump] and is 7

modified by a note stating "Associated with an ECCS subsystem required to be OPERABLE 8

by LCO 3.5.2, 'Reactor Pressure Vessel Water Inventory Control'. New TS 3.5.2 only 9

requires a single ECCS subsystem and the change in required channels reflects that 10 requirement.

11 12 A Channel Check and Channel Functional Test are required at the existing frequency.

13 Calibrating the trip unit, Channel Calibration and Logic System Functional Test are no longer 14 required in Modes 4 and 5.

15 16 In new LCO 3.3.5.2A, the allowable value is unchanged.

17 18 2.3.3.2.2.3 Function 1.d, Low Pressure Coolant Injection-A (LPCI) and Low Pressure Core 19 Spray (LPCS) Subsystems, Manual Initiation, and 20 Function 2.c, LPCI B and LPCI C Subsystems, Manual Initiation 21 22 These functions were moved from current TS 3.3.5.1, Function 1.g and Function 2.f. The 23 following changes are made:

24 25 The applicability is changed. The current TS 3.3.5.1 Applicability for these Functions in 26 Modes 4 and 5 is modified by a note that limits the applicability to when the associated 27 ECCS subsystem(s) are required to be operable per current LCO 3.5.2, "ECCS -

28 Shutdown. The revised applicability is Modes 4 and 5 without exception, to be consistent 29 with the applicability of new LCO 3.5.2, "RPV Water Inventory Control."

30 31 The number of required channels per function is changed from [1] to [1 per subsystem]

32 and is modified by a note stating "Associated with an ECCS subsystem required to be 33 OPERABLE by LCO 3.5.2, 'Reactor Pressure Vessel Water Inventory Control'. New 34 TS 3.5.2 only requires a single ECCS subsystem and the change in required channels 35 reflects that requirement.

36 37 Both the existing TS 3.3.5.1 and the revised TS 3.3.5.2 require a Logic System Functional 38 Test on this function at the same frequency.

39 40 There is no allowable value for this function.

41 42 2.3.3.2.2.4 Function 3.a, High Pressure Core Spray (HPCS) System, Reactor Vessel Water 43 Level - High, Level 8 44 45 This function was moved from current TS 3.3.5.1, Function 3.c. The following changes are 46 made:

47 48 The applicability is changed. The current TS 3.3.5.1 applicability for this function is Modes 4 1

and 5 when the associated ECCS subsystem(s) are required to be operable per existing 2

LCO 3.5.2, "ECCS - Shutdown. The revised applicability is Modes 4 and 5 without 3

exception, to be consistent with the applicability of new LCO 3.5.2, "RPV Water Inventory 4

Control."

5 6

The number of required channels per function is changed from [2] to [1] and is modified by 7

a note stating "Associated with an ECCS subsystem required to be OPERABLE by LCO 8

3.5.2, 'Reactor Pressure Vessel Water Inventory Control'. New TS 3.5.2 only requires a 9

single ECCS subsystem and the change in required channels reflects that requirement.

10 11 A Channel Check and Channel Functional Test are required at the existing frequency.

12 Calibration of the trip units, Channel Calibration, and Logic System Functional Test tests are 13 no longer required in Modes 4 and 5.

14 15 The allowable value in new LCO 3.3.5.2A is unchanged.

16 17 2.3.3.2.2.5 Function 3.b, High Pressure Core Spray (HPCS) System, Condensate Storage 18 Tank Level - Low 19 20 This function was moved from current TS 3.3.5.1, Function 3.d. The following changes are 21 made:

22 23 The applicability is changed. The current TS 3.3.5.1 applicability for this function is Modes 4 24 and 5 when the associated ECCS subsystem(s) are required to be operable per current 25 LCO 3.5.2, "ECCS - Shutdown. The revised applicability is Modes 4 and 5 when HPCS is 26 operable for compliance with new LCO 3.5.2 and aligned to the Condensate Storage Tank.

27 If HPCS is not being credited for meeting the new LCO 3.5.2 requirement for an operable 28 ECCS subsystem, or if HPCS is being credited but is aligned to the suppression pool, this 29 function is unneeded.

30 31 The number of required channels per function is changed from [2] to [1]. New TS 3.5.2 only 32 requires a single ECCS subsystem to be operable, and the change in required channels 33 reflects that requirement.

34 35 A Channel Check and Channel Functional Test are required at the existing frequency.

36 Calibration of the trip units, Channel Calibration, and Logic System Functional Test are no 37 longer required in Modes 4 and 5.

38 39 The allowable value in new LCO 3.3.5.2A is unchanged.

40 41 2.3.3.2.2.6 Functions 3.c and 3.d, High Pressure Core Spray (HPCS) System, HPCS Pump 42 Discharge Pressure - High (Bypass) and HPCS System Flow Rate - Low 43 (Bypass) 44 45 These functions were moved from current TS 3.3.5.1, Function 3.f and 3.g. The following 46 changes are made:

47 48 The applicability is changed. The current TS 3.3.5.1 applicability for this function is Modes 4 1

and 5 when the associated ECCS subsystem(s) are required to be operable per current 2

LCO 3.5.2, "ECCS - Shutdown. The revised applicability is Modes 4 and 5 without 3

exception, to be consistent with the applicability of new LCO 3.5.2, "RPV Water Inventory 4

Control."

5 6

The number of required channels per function is changed from [1] to [1 per pump] and is 7

modified by a note stating "Associated with an ECCS subsystem required to be OPERABLE 8

by LCO 3.5.2, 'Reactor Pressure Vessel Water Inventory Control'. New TS 3.5.2 only 9

requires a single ECCS subsystem and the change in required channels reflects that 10 requirement.

11 12 A Channel Check and Channel Functional Test are required at the existing frequency.

13 Calibration of the trip units, Channel Calibration, and Logic System Functional Test are no 14 longer required in Modes 4 and 5.

15 16 The allowable value is unchanged.

17 18 2.3.3.2.2.7 Function 3.e, High Pressure Core Spray (HPCS) System, Manual Initiation 19 20 This function is moved from current TS 3.3.5.1, Function 3.h. The following changes are made:

21 22 The applicability is changed. The current TS 3.3.5.1 applicability for these functions in 23 Modes 4 and 5 is modified by a note that limits the applicability to when the associated 24 ECCS subsystem(s) are required to be operable per existing LCO 3.5.2, "ECCS -

25 Shutdown. The revised applicability is Modes 4 and 5 without exception, to be consistent 26 with the applicability of new LCO 3.5.2, "RPV Water Inventory Control."

27 28 The number of required channels per function is changed from [1] to [1 per subsystem]

29 and is modified by a note stating "Associated with an ECCS subsystem required to be 30 OPERABLE by LCO 3.5.2, 'Reactor Pressure Vessel Water Inventory Control'. New 31 TS 3.5.2 only requires a single ECCS subsystem and the change in required channels 32 reflects that requirement.

33 34 Both the existing TS 3.3.5.1 and the revised TS 3.3.5.2 require a Logic System Functional 35 Test on this function at the same frequency.

36 37 There is no allowable value for this function.

38 39 2.3.3.2.2.8 Function 4.a, RHR System Isolation Reactor Vessel Water Level - Low, Level 3 40 41 This function was moved from current TS 3.3.6.1, Function 5.c. The following changes are 42 made:

43 44 The function name is changed from "Shutdown Cooling System Isolation Reactor Vessel 45 Water Level - Low, Level 3" to "Residual Heat Removal System Isolation Reactor Vessel 46 Water Level - Low, Level 3.

47 48 The applicability is changed. The current TS 3.3.6.1 applicability for this function is Modes 4 1

and 5. The revised applicability is "when automatic isolation of the associated penetration 2

flow path is credited in calculating drain time.

3 4

The number of required channels is changed from [2], with a column header that states 5

"Required Channels per Trip System," to [2 in one trip system]. This retains the 6

requirement that the two channels must be associated with the same trip system. Only one 7

trip system is required to ensure automatic isolation of one of the two isolation valves will 8

occur on low reactor vessel water level.

9 10 A Channel Check and Channel Functional Test are required at the existing frequency. A 11 calibration of the trip unit, Channel Calibration, Logic System Functional Test, and Isolation 12 System Response Time tests are no longer required in Modes 4 and 5.

13 14 The existing allowable value is retained in new TS 3.3.5.2.

15 16 2.2.3.2.2.9 Function 5.a, Reactor Water Cleanup (RWCU) System Isolation, Reactor Vessel 17 Water Level - Low Low, Level 2 18 19 This function exists in the current STS 3.3.6.1 as Function 4.k. The function is inserted into 20 new STS 3.3.5.2 as follows:

21 22 The current STS 3.3.6.1 applicability for this function is Modes 1, 2, and 3. The applicability 23 in STS 3.3.5.2 is "when automatic isolation of the associated penetration flow path is 24 credited in calculating Drain Time. In other words, if the drain time calculation assumes the 25 RWCU system would be automatically isolated, this function must be operable to perform 26 that function. This is consistent with the definition of drain time and the new TS 3.5.2 27 requirements.

28 29 The number of required channels is changed from [2], with a column header that states 30 "Required Channels per Trip System," to [2 in one trip system]. This retains the 31 requirement that the two channels must be associated with the same trip system. Only one 32 trip system is required to ensure that automatic isolation of one of the two isolation valves 33 will occur on low reactor vessel water level.

34 35 A Channel Check and Channel Functional Test are required at the existing frequency. A 36 calibration of the trip unit, Channel Calibration, Logic System Functional Test, and Isolation 37 System Response Time tests are no longer required in Modes 4 and 5.

38 39 The existing allowable value is retained in LCO 3.3.5.2A.]

40 41 2.3.3.2.3 New TS 3.3.5.2[A or B] Actions Table 42 43 Condition A is applicable when one or more instrument channels are inoperable from 44 Table 3.3.5.2-1. Required Action A.1 directs immediate entry into the condition referenced in 45 Table 3.3.5.2-1 for that channel.

46 47 Condition B is entered when the RHR system isolation and RWCU system isolation functions 1

operability requirements are not met when automatic isolation of the associated penetration flow 2

path is credited in calculating drain time. If the instrumentation is inoperable, Required 3

Action B.1 directs an immediate declaration that the associated penetration flow path(s) are 4

incapable of automatic isolation. Required Action B.2 requires an immediate calculation of drain 5

time.

6 7

Condition C is entered when the Low Reactor Steam Dome Pressure Injection Permissive 8

Functions necessary for ECCS subsystem manual initiation operability requirements are not 9

met. The channel must be placed in the trip condition within one hour.

10 11 For BWR/4 plants choose:

12

[Condition D is entered when the operability requirements for the Core Spray Pump Discharge 13 Flow - Low Bypass, Low Pressure Coolant Injection Pump Discharge Flow - Low Bypass, or 14 manual initiation of these functions operability requirements are not met. The Required Action 15 is to restore the channel to operable status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

16 17 Condition E is entered if the required Action and associated Completion Time of Condition C or 18 D, are not met. Required Action E.1 requires the associated low pressure ECCS injection/spray 19 subsystem to be declared inoperable immediately.]

20 21 For BWR/6 plants choose:

22

[Condition D is entered when the Condensate Storage Tank Level -Low operability 23 requirements are not met. Required Action D requires declaring the HPCS inoperable and 24 aligning the HPCS pump suction to the suppression pool within one hour.

25 26 Condition E is entered if the Reactor Vessel Water Level - High Level 8 instrumentation 27 operability requirements are not met. Action E.1 requires declaring the HCPS system 28 inoperable in 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and restoring the channel to Operable status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

29 30 Condition F is entered if the LPCS Pump Discharge Flow Low (Bypass), LPCI Pump A 31 Discharge Flow Low (Bypass), LPCI Pump B and LPCI Pump C Discharge Flow - Low 32 (Bypass), HPCS Pump Discharge Pressure - High (Bypass) HPCS System Flow Rate - Low -

33 (Bypass) or Manual Initiation associated with these Functions operability requirements are not 34 met. The required action is to restore the channel to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

35 36 Condition G is entered if the required action and associated completion time of Condition C, D, 37 E, or F is not met. Required Action G.1 requires the associated ECCS injection/spray 38 subsystem to be declared inoperable immediately.]

39 40 2.3.3.2.4 New Surveillance Requirements 3.3.5.2.1, 3.3.5.2.2 and 3.3.5.3 41 42 New Table 3.3.5.2-1 specifies which SRs apply for each ECCS function.

43 44 SR 3.3.5.2.1 requires the performance of a Channel Check at a Frequency of [12 hours or in 45 accordance with the Surveillance Frequency Control Program.]

46 47 SR 3.3.5.2.2 requires the performance of a Channel Functional Test at a Frequency of ((92]

48 days or in accordance with the Surveillance Frequency Control Program.]

49 1

SR 3.3.5.2.3 requires the performance of a Logic System Functional Test at a Frequency of 2

((18] months or in accordance with the Surveillance Frequency Control Program.]

3 4

2.3.3.3 Changes to Containment, Containment Isolation Valve and Standby Gas 5

Treatment System Requirements 6

7 The following TS are applicable during OPDRVs and/or contain Actions to suspend OPDRVs 8

when the LCO is not met:

9 10 For BWR/4 plants choose:

11

[3.6.1.3, Primary Containment Isolation Valves (PCIVs) 12 3.6.4.1, [Secondary] Containment 13 3.6.4.2, Secondary Containment Isolation Valves (SCIVs) 14 3.6.4.3, Standby Gas Treatment System]

15 16 For BWR/6 plants choose:

17

[3.6.1.3, Primary Containment Isolation Valves (PCIVs) 18 3.6.4.1, [Secondary] Containment 19 3.6.4.2, Secondary Containment Isolation Valves (SCIVs) 20 3.6.4.3, Standby Gas Treatment System]

21 22 For each of these TS, the applicability and required action sections are being revised to delete 23 references to OPDRVs.

24 25 2.3.3.4 Changes to Control Room Habitability and Temperature Control Requirements 26 27 The following LCOs are applicable during OPDRVs and contain required actions to immediately 28 initiate action to suspend OPDRVs when certain conditions of the LCO are not met:

29 30 For BWR/4 plants choose:

31

[3.7.4, [Main Control Room Environmental Control (MCREC)] System 32 3.7.5, [Control Room Air Conditioning (AC)] System]

33 34 For BWR/6 plants choose:

35

[3.7.3, [Control Room Fresh Air (CRFA)] System 36 3.7.4, [Control Room AC] System]

37 38 The references to OPDRVs are being deleted from the applicability and required actions of 39 these TS.

40 41 2.3.3.5 Changes to Electrical Sources Requirements 42 43 The following TS are applicable in Modes 4 and 5 and currently contain a required action to 44 initiate action to suspend operations with a potential for draining the reactor vessel immediately 45 if certain conditions are not met:

46 47 3.8.2, AC Sources - Shutdown 48 3.8.5, DC Sources - Shutdown 49 3.8.8, Inverters - Shutdown 1

3.8.10, Distribution Systems - Shutdown 2

3 TS 3.8.2 currently requires, in part, with one required offsite circuit inoperable or one required 4

diesel generator inoperable, to initiate action to suspend operations with a potential for draining 5

the reactor vessel immediately.

6 7

TS 3.8.5 currently requires, in part, with one [or more] required DC electrical power 8

subsystem[s] inoperable for reasons other than an inoperable battery charger, to initiate action 9

to suspend operations with a potential for draining the reactor vessel immediately 10 11 TS 3.8.3 currently requires, in part, with one [or more] [required] inverter[s] inoperable, to 12 initiate action to suspend operations with a potential for draining the reactor vessel immediately.

13 14 TS 3.8.10 currently requires, in part, with one or more required AC, DC, [or AC vital bus]

15 electrical power distribution subsystems inoperable, to initiate action to suspend operations with 16 a potential for draining the reactor vessel immediately.

17 18 These required actions are being deleted.

19 20 Note: Insert description of any licensee specific TS changes.

21 22 2.4 APPLICABLE REGULATORY REQUIREMENTS 23 24 Pursuant to 10 CFR 50.90, whenever a holder of an operating license desires to amend the 25 license, application for an amendment must be filed with the Commission fully describing the 26 changes desired, and following as far as applicable, the form prescribed for original 27 applications. The technical information to be included in an application for an operating license 28 is governed in particular by 10 CFR 50.34(b).

29 30 10 CFR 50.36(a)(1) requires each applicant for a license authorizing operation of a utilization 31 facility to include in the application proposed technical specifications in accordance with the 32 requirements of 10 CFR 50.36. The regulation at 10 CFR Section 50.36(a)(1) requires an 33 applicant to submit, as part of the application, a summary statement of the bases or reasons for 34 such specifications, other than those covering administrative controls. However, per 10 CFR 35 50.36(a)(1), these technical specification bases shall not become part of the technical 36 specifications.

37 38 As described in 10 CFR 50.92(a), in determining whether an amendment to a license will be 39 issued to the applicant, the Commission will be guided by the considerations which govern the 40 issuance of initial licenses applicable and appropriate. The general considerations that guide 41 the Commission include, as stated in 10 CFR 50.40(a), how the technical specifications provide 42 reasonable assurance the health and safety of the public will not be endangered. Also, to issue 43 an operating license, of which technical specifications are a part, the Commission must make 44 the findings of 10 CFR 50.57, including finding the 10 CFR 50.57(a)(3)(i) finding that there is 45 reasonable assurance that the activities authorized by the operating license can be conducted 46 without endangering the health and safety of the public.

47 48 As required by 10 CFR 50.36(b), the TS will be derived from the analyses and evaluation 1

included in the safety analysis report, and amendments thereto, submitted pursuant to 10 CFR 2

50.34 [Contents of applications; technical information]. The Commission may include such 3

additional technical specifications as the Commission finds appropriate.

4 5

The categories of items required to be in the TSs are provided in 10 CFR 50.36(c). As required 6

by 10 CFR 50.36(c)(2)(i), the TSs will include LCOs, which are the lowest functional capability 7

or performance levels of equipment required for safe operation of the facility. Per 10 CFR 8

50.36(c)(2)(i), when an LCO of a nuclear reactor is not met, the licensee shall shut down the 9

reactor or follow any remedial action permitted by the TSs until the condition can be met.

10 11 The regulations at 10 CFR 50.36(c)(2)(ii) state that LCOs must be established for each item 12 meeting one of four criteria:

13 14 Criterion 1. Installed instrumentation that is used to detect, and 15 indicate in the control room, a significant abnormal degradation of 16 the reactor coolant pressure boundary.

17 18 Criterion 2. A process variable, design feature, or operating 19 restriction that is an initial condition of a design basis accident or 20 transient analysis that either assumes the failure of or presents a 21 challenge to fission product barrier integrity.

22 23 Criterion 3. A structure, system, or component that is part of the 24 primary success path and which functions or actuates to mitigate a 25 design basis accident or transient that either assumes the failure of 26 or presents a challenge to the integrity of a fission product barrier.

27 28 Criterion 4. A structure, system, or component which operating 29 experience or probabilistic safety assessment has shown to be 30 significant to public health and safety.

31 32 The regulation at 10 CFR 50.36(c)(3) requires TSs to include items in the category of SRs, 33 which are requirements relating to test, calibration, or inspection to assure that the necessary 34 quality of systems and components is maintained, that facility operation will be within safety 35 limits, and that the LCOs will be met. Also, the regulation at 10 CFR 50.36(a)(1) states that a 36 summary statement of the bases or reasons for such specifications, other than those covering 37 administrative controls, shall also be included in the application, but shall not become part of the 38 TSs.

39 40 The NRC staffs guidance for review of TSs is in Chapter 16, Technical Specifications, of 41 NUREG-0800, Revision 3, Standard Review Plan for the Review of Safety Analysis Reports for 42 Nuclear Power Plants (SRP), dated March 2010, (ADAMS Accession No. ML100351425). As 43 described therein, as part of the regulatory standardization effort, the NRC staff has prepared 44 STS for each of the light-water reactor nuclear designs. Choose applicable NUREG: [NUREG-45 1433, Revision 4, contains the STS for BWR/4 plants] or [NUREG 1434, Revision 4, 46 contains the STS for BWR/6 plants)).

47 48

3.0 TECHNICAL EVALUATION

49 1

3.1 DRAIN TIME DEFINITION 2

3 The proposed drain time is the time it would take the RPV water inventory to drain from the 4

current level to the TAF assuming the most limiting of the RPV penetrations flow paths with the 5

largest flow rate, or a combination of penetration flow paths that could open due to a common 6

mode failure, were to open.

7 8

The NRC staff reviewed the proposed drain time definition. For the purpose of NRC staff 9

considerations, the term break describes a pathway for water to drain from the RPV that has 10 not been prescribed in the proposed DRAIN TIME definition. All RPV penetrations below the 11 TAF are included in the determination of drain time as potential pathways. The drain time is 12 calculated by taking the water inventory above the break and dividing by the limiting drain rate 13 until the TAF is reached. The limiting drain rate is a variable parameter depending on the break 14 size and the reduction of elevation head above break location during the drain down event. The 15 discharge point will depend on the lowest potential drain point for each RPV penetration flow 16 path on a plant-specific basis. This calculation provides a conservative approach to determining 17 the drain time of the RPV.

18 19 3.2 WATER SOURCES 20 21 For BWR/4 plants choose:

22

[The proposed LCO 3.5.2 states that, one low pressure Emergency Core Cooling System 23 (ECCS) injection/spray subsystem shall be OPERABLE.]

24 25 For BWR/6 plants choose:

26

[The proposed LCO 3.5.2 states that, one ECCS injection/spray subsystem shall be 27 OPERABLE.]

28 29 The NRC staff reviewed the water sources that would be applicable to the proposed TS 3.5.2.

30 The ECCS pumps are high-capacity pumps, with flow rates of thousands of gallons per minute 31 (gpm). Most RPV penetration flow paths would have a drain rate on the order of tens or 32 hundreds of gpm. The automatic initiation of an ECCS pump would provide the necessary 33 water source to counter these expected drain rates. The LPCI subsystem is to be considered 34 operable during alignment and operation for decay heat removal if capable of being manually 35 realigned and not otherwise inoperable. Decay heat removal in MODEs 4 and 5 is not affected 36 by the proposed change as these requirements on the number of RHR shutdown cooling 37 subsystems that must be operable and in operation to ensure adequate decay heat removal 38 from the core are unchanged. For BWR/4 plants choose: [These requirements can be found 39 in TS 3.4.9, Residual Heat Removal (RHR) Shutdown Cooling System - Cold Shutdown, 40 TS 3.9.8, Residual Heat Removal (RHR) - High Water Level, and TS 3.9.10, Residual 41 Heat Removal (RHR) - Low Water Level.] For the BWR/6 plants choose: [These 42 requirements can be found in TS 3.4.10, Residual Heat Removal (RHR) Shutdown 43 Cooling System - Cold Shutdown, TS 3.9.8, Residual Heat Removal (RHR) - High Water 44 Level, and TS 3.9.10, Residual Heat Removal (RHR) - Low Water Level.] Based on these 45 considerations, the NRC staff finds the water sources provide assurances that the lowest 46 functional capability required for safe operation is maintained and supports the safety limit.

47 48 3.3 TS 3.5.2 - REACTOR PRESSURE VESSEL (RPV) WATER INVENTORY CONTROL 1

2 The proposed TS 3.5.2, Reactor Pressure Vessel (RPV) Water Inventory Control, LCO 3

contains two parts. The first part states that drain time of RPV water inventory to the TAF shall 4

be 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . For BWR/4 choose: [The second part states, one low pressure ECCS 5

injection/spray subsystem shall be OPERABLE.] For BWR/6 plants choose: [The second 6

part states, one ECCS injection/spray subsystem shall be OPERABLE.] The proposed 7

applicability for TS 3.5.2 is MODEs 4 and 5.

8 9

The NRC staff reviewed the proposed TS 3.5.2, focusing on ensuring the fuel remains covered 10 with water and the changes made compared to the current TS. The proposed TS 3.5.2 contains 11 Conditions A through E based on either required ECCS injection/spray subsystem operability or 12 drain time.

13 14 The current TS LCO states that two ECCS injection/spray subsystems shall be operable, 15 whereas the proposed LCO 3.5.2 states that only one ECCS injection/spray subsystem shall be 16 operable. This change is reflected in Condition A. The change from two ECCS injection/spray 17 subsystem to one ECCS injection/spray subsystem is because this redundancy is not required.

18 With one ECCS injection/spray subsystem and non-safety related injection sources, defense-in-19 depth will be maintained. The defense-in-depth measure is consistent with other events 20 considered during shutdown with no additional single failure assumed. The drain time controls, 21 in addition to the required ECCS injection/spray subsystem, provide reasonable assurance that 22 an unexpected draining event can be prevented or mitigated before the RPV water level would 23 be lowered to the TAF.

24 25 The proposed Condition A states that if the required ECCS injection/spray subsystem is 26 inoperable, it is to be restored to operable status within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . Proposed Condition B states 27 that if Condition A is not met, a method of water injection capable of operating without offsite 28 electrical power should be established immediately. The proposed Condition B provides 29 adequate assurance of an available water source should Condition A not be met within the 30 4-hour completion time.

31 32 The proposed Condition C states that for a drain time < 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months and 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , to (1) verify 33

[secondary containment] boundary is capable of being established in less than 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , and 34 (2) verify each [secondary containment] penetration flow path is capable of being isolated in 35 less than 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , and (3) verify one standby gas treatment subsystem is capable of being 36 placed in operation in less than 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . The proposed Condition C provides adequate 37 protection should the DRAIN TIME be < 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months and 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months because of the ability to 38 establish secondary containment, isolate additional flow paths, and have the standby gas 39 treatment subsystem operable.

40 41 The proposed Condition D states that when drain time < 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months to (1) immediately initiate 42 action to establish an additional method of water injection with water sources capable of 43 maintaining RPV water level > TAF for 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , (2) immediately initiate action to establish 44

[secondary] containment boundary, (3) immediately initiate action to isolate each [secondary]

45 containment penetration flow path or verify it can be manually isolated from the control room, 46 and (4) immediately initiate action to verify one standby gas treatment subsystem is capable of 47 being placed in operation. Additionally, there is a note stating that required ECCS 48 injection/spray subsystem or additional method of water injection shall be capable of operating 49 without offsite electrical power, which is similar to proposed Condition B. The current TS for 1

Condition D are similar to the proposed for when Required Action C.2 is not met. The proposed 2

Condition D provides adequate protection should the DRAIN TIME be < 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months because of the 3

ability to establish secondary containment, isolate additional flow paths, and have the standby 4

gas treatment subsystem operable.

5 6

The proposed Condition E states that when the required action and associated completion time 7

of Condition C or D is not met, or the drain time is < 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months , then initiate action to restore drain 8

time to 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months immediately. The proposed Condition E is new, as it is not present in the 9

current TS. The proposed Condition E is acceptable as it provides the necessary step to 10 restore the drain time to 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months should the other conditions not be met, or if the drain time is 11

< 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months .

12 13 Based on the NRC staffs review, the proposed changes to TS 3.5.2 are acceptable based on 14 the actions taken to mitigate the water level reaching the TAF with the water sources available 15 and maintaining drain time 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The LCO correctly specifies the lowest functional 16 capability or performance levels of equipment required for safe operation of the facility. There is 17 reasonable assurance that the required actions to be taken when the LCO is not met can be 18 conducted without endangering the health and safety of the public 19 20 The existing TS 3.3.5.2, "RCIC System Instrumentation," is renumbered as TS 3.3.5.3. This 21 increases consistency within the TS as the Reactor Core Isolation Cooling (RCIC) System is 22 discussed in the section on TS 3.5.3. NOTE: Some licensees may choose to assign a different 23 number to this new TS. This is an acceptable alternative.

24 25 3.4 TS 3.3.5.2, REACTOR PRESSURE VESSEL WATER INVENTORY CONTROL 26 INSTRUMENTATION 27 28 The purpose of the RPV Water Inventory Control Instrumentation is to support the requirements 29 of new TS LCO 3.5.2, and the definition of drain time. There are instrumentation and controls 30 that are required for manual initiation or required as a permissive or operational controls on the 31 equipment of the systems that provide water injection capability, certain start commands, and 32 isolation functions. These instruments are required to be operable if the systems that provide 33 water injection and isolation functions are to be considered operable as described in the safety 34 evaluation of new TS 3.5.2. In some cases the reactor operators have alternate, often more 35 complex means, of starting and injecting water than the preferred simple push button start.

36 37 For BWR/4 plants choose:

38

[Specifically, the RPV Water Inventory Control Instrumentation supports operation of the 39 Core Spray and LPCI including manual initiation when needed as well as the system 40 isolation of the RHR system and the RWCU system. The equipment involved with each 41 of these systems is described in the evaluation of TS 3.5.2 and the Bases for LCO 3.5.2.]

42 43 For BWR/6 plants choose:

44

[Specifically, the RPV Water Inventory Control Instrumentation supports operation of the 45 LPCI with subsystems LPCI A, LPCI B, and LPCI C, LPCS, and HPCS, including manual 46 initiation when needed as well as the system isolation of the RHR system and the RWCU 47 system. The equipment involved with each of these systems is described in the 48 evaluation of TS 3.5.2 and the Bases for LCO 3.5.2.]

49 1

3.4.1 Proposed TS 3.3.5.2 LCO and Applicability 2

3 The proposed LCO 3.3.5.2 states, The RPV Water Inventory Control instrumentation for each 4

Function in Table 3.3.5.2-1 shall be OPERABLE.

5 6

The applicability states, "According to Table 3.3.5.2-1."

7 8

Section 3.3.1 of TSTF-542, states:

9 10 11 Table 3.3.5.2-1 contains those instrumentation Functions needed 12 to support manual initiation of the ECCS injection/spray 13 subsystem required by LCO 3.5.2, and automatic isolation of 14 penetration flow paths that may be credited in a calculation of 15 Drain Time. The Functions in Table 3.3.5.2-1 are moved from 16 existing TS 3.3.5.1, "ECCS Instrumentation," and TS 3.3.6.1, 17 "Primary Containment Isolation Instrumentation" Functions that 18 are required in Modes 4 or 5 or during OPDRVs. Creation of 19 TS 3.3.5.2 places these Functions in a single location with 20 requirements appropriate to support the safety function for 21 TS 3.5.2.

22 23 If plant-specific design and TS require different functions to 24 support manual initiation of an ECCS subsystem, those functions 25 should be included in TS 3.3.5.2.

26 27 28 3.4.2 Proposed TS 3.3.5.2 Actions 29 30 TS 3.3.5.2 contains actions to be followed when the LCO is not met.

31 32 TSTF-542, Section 3.3.2, Proposed TS 3.3.5.2 Actions, discusses the actions of TS 3.3.5.2 33 and LCO 3.3.5.2. The NRC staff finds these actions are sufficient and necessary, because 34 when one or more instrument channels are inoperable the equipment and function controlled by 35 these instruments cannot complete the required function in the normal manner and these 36 actions direct the licensee to take appropriate actions as necessary and enter immediately into 37 the Conditions referenced in Table 3.3.5.2-1. These actions satisfy the requirements of 10 CFR 38 50.36(c)(3) by providing a remedial action permitted by the TS until the LCO can be met. The 39 remedial actions provide reasonable assurance that an unexpected draining event can be 40 prevented or mitigated before the RPV water level would be lowered to the TAF.

41 42 For BWR/4 plants choose the following Section 3.4.3:

43 3.4.3 Proposed TS 3.3.5.2 Actions 44 45 TSTF-542, Section 3.3.2, Proposed TS 3.3.5.2 Actions, discusses the actions of TS 3.3.5.2 46 and LCO 3.3.5.2. The NRC staff finds these actions are sufficient and necessary, because 47 when one or more instrument channels are inoperable the equipment and function controlled by 48 these instruments cannot complete the required function in the normal way, and these actions 49 direct the licensee to take appropriate actions as required. The actions provide reasonable 1

assurance that an unexpected draining event can be prevented or mitigated before the RPV 2

water level would be lowered to the TAF.

3 4

Action A is applicable when one or more instrument channels are inoperable from 5

Table 3.3.5.2-1 and directs the licensee to immediately enter the Condition referenced in 6

Table 3.3.5.2-1 for that channel.

7 8

Action B (concerning the RHR system Isolation and RWCU system Isolation functions) are 9

applicable when automatic isolation of the associated penetration flow path is credited as not 10 having to be considered as a path for potential drainage in calculating drain time. If the 11 instrumentation is inoperable, Required Action B.1 directs an immediate declaration that the 12 associated penetration flow path(s) are incapable of automatic isolation. Required Action B.2 13 requires a re-calculation of drain time, but automatic isolation of the affected penetration flow 14 paths cannot be credited.

15 16 Action C (concerning low reactor steam dome pressure permissive Functions necessary for 17 ECCS subsystem manual initiation) addresses an event in which the permissive is inoperable 18 and manual initiation of ECCS using the control board pushbuttons is prevented. The function 19 must be placed in the trip condition within one hour. With the permissive function instrument in 20 the trip condition, manual initiation may now be performed using the preferred control board 21 pushbuttons. This one-hour completion time is acceptable, because despite the preferred start 22 method being prevented, the reactor operator can take manual control of the pump and the 23 injection valve to inject water into the RPV and achieve the safety function. The time of one 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months also provides reasonable time for evaluation and placing the channel in trip.

25 26 Action D (concerning pump discharge flow bypass Functions and the manual initiation 27 Functions) addresses actions when the bypass is inoperable and then there is a risk that the 28 associated ECCS pump could overheat when the pump is operating and the associated 29 injection valve is not fully open. In this condition, the operator can take manual control of the 30 pump and the injection. Similar to justification in Action C, while this is not the preferred 31 method, if a manual initiation function is inoperable, the ECCS subsystem pumps can be started 32 manually and the valves can be opened manually. The 24-hour completion time is acceptable, 33 because the functions can be performed manually and it allows time for the operator to evaluate 34 and have necessary repairs completed. Unlike the failure of a pushbutton that may concern 35 electronic component repairs, mechanical components may be involved in repairs, testing, and 36 return to service of pumps and valves. This further justifies a 24-hour completion time as 37 appropriate.

38 39 Action E is needed and becomes necessary, if the required action and associated completion 40 time of Condition C or D, are not met. If they are not met, then the associated low pressure 41 ECCS injection/spray subsystem may be incapable of performing the intended function, and the 42 ECCS subsystem must be declared inoperable immediately.]

43 44 For BWR/6 plants choose the following Section 3.4.3:

45 3.4.3 Proposed TS 3.3.5.2 Actions 46 47 TSTF-542, Section 3.3.2, Proposed TS 3.3.5.2 Actions, discusses the actions of TS 3.3.5.2 48 and LCO 3.3.5.2. The NRC staff finds these actions are sufficient and necessary, because 49 when one or more instrument channels are inoperable the equipment and function controlled by 1

these instruments cannot complete the required function in the normal way and these actions 2

direct the licensee to take appropriate actions as required. The remedial actions provide 3

reasonable assurance that an unexpected draining event can be prevented or mitigated before 4

the RPV water level would be lowered to the TAF.

5 6

Action A is applicable when one or more instrument channels are inoperable from Table 3.3.5.2 7

and directs the licensee to immediately enter the condition referenced in Table 3.3.5.2-1 for that 8

channel.

9 10 Action B (concerning the RHR system isolation and RWCU system isolation functions) are 11 applicable when automatic isolation of the associated penetration flow path is credited as not 12 having to be considered as a path for potential drainage in calculating drain time. If the 13 instrumentation is inoperable, Required Action B.1 directs an immediate declaration that the 14 associated penetration flow path(s) are incapable of automatic isolation. Required Action B.2 15 requires a re-calculation of drain time, but automatic isolation of the affected penetration flow 16 paths cannot be credited.

17 18 Action C (concerning low reactor steam dome pressure permissive Functions necessary for 19 ECCS subsystem manual initiation) addresses an event in which the permissive is inoperable 20 and manual initiation of ECCS using the control board pushbuttons is prevented. The function 21 must be placed in the trip condition within one hour. With the permissive function instrument in 22 the trip condition, manual initiation may now be performed using the preferred control board 23 pushbuttons. This one hour completion time is acceptable, because despite the preferred start 24 method being prevented, the reactor operator can take manual control of the pump and the 25 injection valve to inject water into the RPV and achieve the safety function. The time of one 26 hour3.009259e-4 days 0.00722 hours 4.298942e-5 weeks 9.893e-6 months also provides reasonable time for evaluation and placing the channel in trip.

27 28 Action D (concerning loss of adequate water supply for the HPCS System), addresses an event 29 in which there is an inadequate water supply. The instrumentation functions have the ability to 30 detect low-water setpoint in the Condensate Storage Tank and actuate valves to realign HPCS 31 suction water source to the Suppression Pool. The Condensate Storage Tank Level - Low 32 Function indicates multiple, inoperable channels within the same Function resulting in a loss of 33 the automatic ability to swap suction to the Suppression Pool. The HPCS system must be 34 declared inoperable within one hour or the HPCS pump suction must be realigned to the 35 Suppression Pool, since, if realigned, the Function is already performed. This one hour is 36 acceptable, because it provides sufficient time to take the action in order to minimize the risk of 37 HPCS being needed without an adequate water source by allowing time for restoration or 38 alignment of the HPCS pump suction to the suppression pool.

39 40 Action E (concerning HPCS high water level Function in the RPV) addresses actions when this 41 instrument function is inoperable. HPCS Reactor Vessel Water Level - High, Level 8 function 42 ensures that appropriate actions are taken if the HPCS Reactor Vessel Water Level - High, 43 Level 8 Function is inoperable. If the inoperability results in the channel being tripped, the 44 HPCS pump discharge valve will not open and HPCS injection is prevented. In that case the 45 HPCS System must be declared inoperable within one hour, and the function must be restored 46 to operable status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The one hour completion time is acceptable, because of the 47 ability to manually start the HPCS pumps and open the discharge valve. The 24-hour 48 completion time is acceptable, because it allows time for the operator to evaluate and arrange 1

for repairs.

2 3

Action F (concerning pump discharge flow bypass Functions and the manual initiation 4

Functions) addresses an event in which the bypass is inoperable and there is a risk that the 5

associated ECCS pump could overheat when the pump is operating and the associated 6

injection valve is not fully open. In this condition, the operator can take manual control of the 7

pump and the injection. Similar to justification in Action C, while this is not the preferred 8

method, if a manual initiation function is inoperable, the ECCS subsystem pumps can be started 9

manually and the valves can be opened manually. The 24-hour completion time is acceptable, 10 because the functions can be performed manually and it allows time for the operator to evaluate 11 and have necessary repairs completed. Unlike the failure of a pushbutton that may concern 12 electronic component repairs, mechanical components may be involved in repairs, testing, and 13 return to service of pumps and valves further justifying a 24-hour completion time as 14 appropriate.

15 16 Action G is needed and becomes necessary, if the required action and associated completion 17 time of Condition C, D, E, or F are not met. If they are not met, then the associated low 18 pressure ECCS injection/spray subsystem may be incapable of performing the intended 19 function, and the ECCS subsystem must be declared inoperable immediately.

20 21 3.4.4 Proposed TS 3.3.5.2 Surveillances 22 23 The TS 3.3.5.2 SR include Channel Checks, Channel Functional Tests, and Logic System 24 Functional Tests. There are three SRs numbered SR 3.3.5.2.1, SR 3.3.5.2.2, and SR 3.3.5.2.3.

25 The NRC staff finds these tests are sufficient and adequate, because they are essential to 26 ensure the Functions of TS 3.3.5.2 are operable (i.e., capable of performing the specified safety 27 function in support of TS 3.5.2, Drain Time, and the protection from a potential drain down of the 28 RPV in Modes 4 and 5). The NRC staff finds the proposed TS 3.3.5.2 surveillances of LCO 29 3.5.2 as described in Section 3.3.3 satisfies 10 CFR 50.36(c)(3) by providing the specific SRs 30 relating to test, calibration, or inspection to assure that the necessary quality of systems and 31 components is maintained.

32 33 SR 3.3.5.2.1 requires a Channel Check and is applied to all functions except manual initiation.

34 Performance of the Channel Check ensures that a gross failure of instrumentation has not 35 occurred. A Channel Check is normally a comparison of the parameter indicated on one 36 channel to a similar parameter on other related channels. A Channel Check is significant in 37 assuring that there is a low probability of an undetected complete channel failure and is a key 38 safety practice to verifying the instrumentation continues to operate properly between each 39 Channel Functional Test. The frequency of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , or in accordance with the Surveillance 40 Frequency Control Program, is consistent with the existing requirements and supports operating 41 shift situational awareness.

42 43 SR 3.3.5.2.2 requires a Channel Functional Test and is applied to all functions except manual 44 initiation. A Channel Functional Test is the injection of a simulated or actual signal into the 45 channel as close to the sensor as practicable to verify operability of all devices in the channel 46 required for channel operability. It is performed on each required channel to ensure that the 47 entire channel will perform the intended function. The frequency is in accordance with the 48 Surveillance Frequency Control Program or 92 days. The applicant states, This is acceptable 49 because it is consistent with the existing requirements for these Functions and is based upon 1

operating experience that demonstrates channel failure is rare. Since periods in MODEs 4 and 2

5 as refueling outages are often in the order of 30 days or less, licensees could include this SR, 3

if desired, as part of a refueling activity.

4 5

SR 3.3.5.2.3 requires a Logic System Functional Test and is only applied to the manual initiation 6

functions. The Logic System Functional Test is a test of all logic components required for 7

operability of a logic circuit, from as close to the sensor as practicable up to, but not including, 8

the actuated device, and demonstrates the operability of the required manual initiation logic for 9

a specific channel. The ECCS subsystem functional testing performed in proposed SR 3.5.2.7 10 overlaps this surveillance to complete testing of the assumed safety function. The TSTF-542, 11 Section 3.2.4.6, states:

12 13 14 The Frequency of [18] months, or in accordance with the 15 Surveillance Frequency Control Program, is consistent with the 16 existing requirements, and is based upon operating experience 17 that that has shown that these components usually pass the 18 Surveillance when performed at this Frequency.

19 20 21 There are no SRs included to verify or adjust the instrument setpoint derived from the allowable 22 value using a Channel Calibration or a surveillance to calibrate the trip unit. TSTF-542, 23 Section 3.3.3, states, 24 25 26 A draining event in Mode 4 or 5 is not an analyzed accident and, 27 therefore, there is no accident analysis on which to base the 28 calculation of a setpoint. The purpose of the Functions is to allow 29 ECCS manual initiation or to automatically isolate a penetration 30 flow path, but no specific RPV water level is assumed for those 31 actions. Therefore, the Mode 3 Allowable Value was chosen for 32 use in Modes 4 and 5 as it will perform the desired function.

33 Calibrating the Functions in Modes 4 and 5 is not necessary, as 34 TS 3.3.5.1 and TS 3.3.6.1 continue to require the Functions to be 35 calibrated on an [18] month Frequency.

36 37 And:

38 39 A draining event in Mode 4 or 5 is not an analyzed accident and, 40 therefore, there are no accident analysis assumptions on 41 response time.

42 43 44 This is acceptable, because this is adequate to ensure the channel responds with the required 45 pumping systems to inject water when needed and isolation equipment to perform when 46 commanded.

47 48 ECCS Response Time and Isolation System Response Time testing ensure that the individual 1

channel response times are less than or equal to the maximum values assumed in the accident 2

analysis. TS 3.3.5.2 does not include SRs to participate in any ECCS Response Time testing 3

and Isolation System Response Time testing. This is acceptable because the purpose of these 4

tests are to ensure that the individual channel response times are less than or equal to the 5

maximum values assumed in the accident analysis, but a draining event in Mode 4 or 5 is not an 6

analyzed accident and, therefore, there are no accident analysis assumptions on response time 7

and there are alternate manual methods for achieving the safety function. A potential draining 8

event in MODEs 4 and 5 is a slower event than a LOCA. More significant protective actions are 9

required as the calculated drain time decreases.

10 11 3.4.5 Conclusion of NRC Staff Review of TS 3.3.5.2 12 13 The NRC staff finds that proposed TS 3.3.5.2 and LCO 3.3.5.2 satisfies Criterion 4 of 14 10 CFR 50.36(c)(3), because specific instrumentation is provided that helps prevent or mitigate 15 a potential RPV drain down event. Operating experience highlights that RPV draining events 16 are potentially significant to public health and safety, as established in the following NRC 17 documents:

18 19

1.

Information Notice 84-81 "Inadvertent Reduction in Primary Coolant Inventory in 20 Boiling Water Reactors During Shutdown and Startup," November 1984.

21

2.

Information Notice 86-74, "Reduction of Reactor Coolant Inventory Because of 22 Misalignment of RHR Valves," August 1986.

23

3.

Generic Letter 92-04, "Resolution of the Issues Related to Reactor Vessel Water 24 Level Instrumentation in BWRs Pursuant to 10 CFR 50.54(f)," August 1992.

25

4.

NRC Bulletin 93-03, "Resolution of Issues Related to Reactor Vessel Water Level 26 draining event in Mode 4 Instrumentation in BWRs," May 1993.

27 28 The NRC staff finds that proposed LCO 3.3.5.2 correctly specifies the lowest functional 29 capability or performance levels of equipment required for safe operation of the facility. There is 30 reasonable assurance that the required actions to be taken when the LCO is not met can be 31 conducted without endangering the health and safety of the public.

32 33 3.5 TABLE 3.3.5.2-1, "RPV WATER INVENTORY CONTROL INSTRUMENTATION" 34 35 In order to support the requirements of TS 3.5.2, and LCO 3.5.2, Reactor Pressure Vessel 36 (RPV) Water Inventory Control, and the definition of DRAIN TIME; the instrumentation 37 requirements are designated in Table 3.3.5.2-1. These instruments are required to be operable 38 if the systems that provide water injection and isolation functions are to be considered operable 39 as described in the NRC staffs evaluation of TS 3.5.2.

40 41 Table 3.3.5.2-1 specifies the instrumentation that shall be operable for each function in the table 42 for Modes 4 and 5 (or other specified conditions), the required number of channels per function, 43 conditions referenced from required action A.1, SR for the functions, [the allowable value 44 (removed this if version B)], and footnotes concerning items of the table.

45 46 Note: Table 3.3.5.2-1 version A has a column for the allowable value. Version A has the 47 allowable value in brackets. The brackets indicate that a plant-specific value should be used in 48 the LAR to adopt TSTF-542. Table 3.3.5.2-1 version B does not have a column for the 1

allowable value.

2 3

Proposed Table TS 3.3.5.2-1, RPV Water Inventory Control Instrumentation, presents details 4

on the functions required to support the equipment and functions of TS 3.5.2. The NRC staff 5

finds the presentation in this table acceptable, because this section sufficiently discusses the 6

purpose of the functions, the applicability, the number of required channels, the references to 7

the Condition to be entered by letter (e.g., A, B, C) if the function is inoperable, the applicable 8

SRs, [the selection of the allowable value], and justification of differences between the 9

existing and proposed TS functions. This RPV Water Inventory Control Instrumentation set is 10 acceptable, because it is adequate to ensure the instruments of the channels responds with the 11 required accuracy permitting pumps systems to operate to inject water when needed and 12 isolation of equipment when commanded to support the prevention of or mitigate a potential 13 RPV draining event.

14 15 Each of the ECCS subsystems in MODEs 4 and 5 are initiated by manual pushbutton.

16 Automatic initiation of an ECCS injection/spray subsystem may be undesirable because it could 17 lead to overflowing the RPV cavity, due to injection rates of thousands of gallons per minute.

18 Thus, there is adequate time to take manual actions (e.g., hours versus minutes). Considering 19 the action statements as the drain time decreases (the proposed TS 3.5.2, Action E, prohibits 20 plant conditions that could result in drain times less than one hour), therefore, there is sufficient 21 time for the reactor operators to take manual action to stop the draining event, and to manually 22 start an ECCS injection/spray subsystem or the additional method of water injection as needed.

23 Consequently, there is no need for automatic initiation of ECCS to respond to an unexpected 24 draining event. This is acceptable, because a draining event is a slow evolution when 25 compared to a design basis LOCA assumed to occur at a significant power level.

26 27 For BWR/4 choose the following Section 3.5.1:

28 3.5.1 Proposed Table 3.3.5.2-1, Functions 29 30 For the Table 3.3.5.2-1 Functions 1.a and 2.a, BWR/4 CS and LPCI Systems, Reactor Steam 31 Dome Pressure - Low (Injection Permissive), these signals are used as permissives and 32 protection for these low pressure ECCS injection/spray subsystem manual initiation functions.

33 This function ensures that the reactor pressure has fallen to a value below these subsystems' 34 maximum design pressure before permitting the operator to open the injection valves of the low 35 pressure ECCS subsystems. Even though during MODEs 4 and 5 the reactor steam dome 36 pressure is expected to virtually always be below the ECCS maximum design pumping 37 pressure, the Reactor Steam Dome Pressure - Low signals are required to be operable and 38 capable of permitting initiation of the ECCS.

39 40 For the Table 3.3.5.2-1 Functions 1.b and 2.b, CS and LPCI Systems, Pump Discharge Flow -

41 Low (Bypass), these minimum flow instruments are provided to protect the associated low 42 pressure ECCS pumps from overheating when the pump is operating and the associated 43 injection valve is not fully open. The minimum flow line valve is opened when low flow is 44 sensed, and the valve is automatically closed when the flow rate is adequate to protect the 45 pump. Use for Version A TS: [Where applicable, allowable values specified are high enough 46 to ensure that the pump flow rate is sufficient to protect the pump, yet low enough to ensure that 47 the closure of the minimum flow valve is initiated to allow full flow into the core.] The LPCI 48 minimum flow valves are time delayed such that the valves will not open for 10 seconds after 49 the switches detect low flow. This time delay is acceptable, because it is provided to limit 1

reactor vessel inventory loss during the startup of the RHR shutdown cooling mode.

2 3

For the Table 3.3.5.2-1 Functions 1.c and 2.c, CS System Manual Initiation and LPCI, System 4

Manual Initiation, the manual initiation pushbutton channels introduce signals into the 5

appropriate ECCS logic to provide manual initiation capability. There is one push button for 6

each of the CS and LPCI subsystems (i.e., two for CS and two for LPCI). There is no allowable 7

value for this Function since the channels are mechanically actuated based solely on the 8

position of the push buttons. An instrument channel of the Manual Initiation Function (one 9

channel per subsystem) is required to be Operable in MODEs 4 and 5 when the associated 10 ECCS subsystems are required to be Operable per LCO 3.5.2.

11 12 For the Table 3.3.5.2-1 Function 3.a, RHR System Isolation, Reactor Vessel Water Level - Low, 13 Level 3, the function is only required to be operable when automatic isolation of the associated 14 penetration flow path is credited in the drain time calculation. The number of required 15 instrument channels is [2 in one trip system], which retains the requirement that the two 16 instrument channels must be associated with the same trip system. Each trip system isolates 17 one of two redundant isolation valves, and only one trip system is required to be operable to 18 ensure that automatic isolation of one of the two isolation valves will occur on low reactor vessel 19 water level indication. Use for Version A TS: [The allowable value was chosen to be the 20 same as the Primary Containment Isolation Instrumentation Reactor Vessel Water Level - Low, 21 Level 3 Allowable Value from LCO 3.3.6.1.]

22 23 For the Table 3.3.5.2-1 Function 4.a, RWCU, System Isolation, Reactor Vessel Water Level -

24 Low Low, Level 2, the function is only required to be operable when automatic isolation of the 25 associated penetration flow path is credited in the drain time calculation. The number of 26 required channels is [2 in one trip system], which retains the requirement that the two 27 instrument channels must be associated with the same trip system. Only one trip system is 28 required to be operable to ensure that automatic isolation of one of the two isolation valves will 29 occur on low reactor vessel water level. Use for Version A TS: [Allowable value was chosen 30 to be the same as the ECCS Reactor Vessel Water Level - Low Low, Level 2 Allowable Value 31 from LCO 3.3.5.1.]

32 33 For BWR/6 choose the following Section 3.5.2:

34 3.5.2 Proposed Table 3.3.5.2.-1, Functions 35 36 For the Table 3.3.5.2-1 Functions 1.a and 2.a, LPCS and LPCI Systems, Reactor Steam Dome 37 Pressure - Low (Injection Permissive), these signals are used as permissives and protection for 38 these low pressure ECCS injection/spray subsystem manual initiation functions. This function 39 ensures that the reactor pressure has fallen to a value below these subsystems' maximum 40 design pressure before permitting the operator from opening the injection valves of the low 41 pressure ECCS subsystems. Even though during MODEs 4 and 5 the reactor steam dome 42 pressure is expected to virtually always be below the ECCS maximum design pumping 43 pressure, the Reactor Steam Dome Pressure - Low signals are required to be operable and 44 capable of permitting initiation of the ECCS.

45 46 For the Table 3.3.5.2-1 Functions 1.b, 1.c, and 2.b, LPCS and LPCI Systems Low Pressure 47 Coolant Injection and Low Pressure Core Spray Pump Discharge Flow - Low (Bypass), these 48 instruments are provided to protect the associated low pressure ECCS pump from overheating 49 when the pump is operating and the associated injection valve is not fully open. The minimum 1

flow line valve is opened when low flow is sensed, and the valve is automatically closed when 2

the flow rate is adequate to protect the pump. Use for Version A TS: [Where applicable 3

allowable values specified are high enough to ensure that the pump flow rate is sufficient to 4

protect the pump, yet low enough to ensure that the closure of the minimum flow valve is 5

initiated to allow full flow into the core.]

6 7

For the Table 3.3.5.2-1 Functions 1.d and 2.c, LPCS and LPCI Systems, Manual Initiation, the 8

manual initiation pushbutton channels introduce signals into the appropriate ECCS logic to 9

provide manual initiation capability. There is one pushbutton for each subsystem in the two 10 divisions of low pressure ECCS (i.e., Division 1 ECCS, LPCS and LPCI A; Division 2 ECCS, 11 LPCI B and LPCI C). There are four subsystems, thus four pushbuttons for the low pressure 12 ECCS. The only manual initiation function required to be operable is that associated with the 13 ECCS subsystem that is required to be operable by LCO 3.5.2. Use for Version A TS: [Since 14 the channels are mechanically actuated based solely on the position of the pushbuttons, there is 15 no allowable value for this function.] When this instrument function is inoperable, manual 16 initiation with the control board push buttons is inoperable. However, the ECCS pumps can be 17 started manually and valves can be opened manually by the reactor operator. This is not the 18 preferred condition.

19 20 For the Table 3.3.5.2-1 Functions 3.a, HPCS System Reactor Vessel Water Level - High, Level 21 8, the High RPV water level, Level 8 signal, is used to close the HPCS injection valve to prevent 22 overflow into the main steam lines (MSLs). One instrument channel associated with the HPCS 23 system is required to be operable to support LCO 3.5.2. Use for Version A TS: [The 24 LCO 3.3.5.2 allowable value is chosen to isolate flow from the HPCS system prior to water 25 overflowing into the MSLs.]

26 27 For the Table 3.3.5.2-1 Functions 3.b, HPCS System, Condensate Storage Tank Level - Low, 28 the low level signal in the Condensate Storage Tank (CST) indicates the lack of an adequate 29 supply of makeup water from this primary source for HPCS. Normally, the water source for the 30 suction for HPCS is the CST. If the water level in the CST falls below a preselected level, 31 instrumentation logic controls valves so suction is then pulled from the Suppression Pool. First 32 the Suppression Pool suction valve is automatically opened and then the CST suction valve is 33 automatically closed in a manner to ensure that an adequate supply of makeup water is 34 available to the HPCS pump. The Condensate Storage Tank Level - Low signals are initiated 35 from two level transmitters. The Condensate Storage Tank Level - Low Function Allowable 36 Value is high enough to ensure adequate pump suction head while water is being taken from 37 the CST.

38 39 For the Table 3.3.5.2-1 Functions 3.c and 3.d, HPCS System, HPCS Pump Discharge Pressure 40

- High (Bypass) and HPCS System Flow Rate - Low (Bypass), the minimum flow instruments 41 are provided to protect the HPCS pump from overheating when the pump is operating and the 42 associated injection valve is not fully open. The minimum flow line valve is opened when low 43 flow and high pump discharge pressure are sensed, and the valve is automatically closed when 44 the flow rate is adequate to protect the pump or the discharge pressure is low (indicating the 45 HPCS pump is not operating).

46 47 For the Table 3.3.5.2-1 Function 3.e, HPCS System, Manual Initiation, the Manual Initiation 1

push button channel introduces a signal into the HPCS logic to provide manual initiation 2

capability. There is one pushbutton for the HPCS system.

3 4

For the Table 3.3.5.2-1 Function 4.a, BWR/6 RHR System Isolation, Reactor Vessel Water 5

Level - Low, Level 3, the Function is only required to be operable when automatic isolation of 6

the associated RHR system penetration flow path is credited in calculating drain time. The 7

definition of drain time allows crediting the closing of penetration flow paths that are capable of 8

being automatically isolated by RPV water level isolation instrumentation prior to the RPV water 9

level dropping below the TAF, but if the instrument function is inoperable, a closed path cannot 10 be credited and a drain time calculation must be re-performed.

11 12 For the Table 3.3.5.2-1 Function 5.a, RWCU System Isolation, Reactor Vessel Water Level -

13 Low Low, Level 2, the Function is only required to be Operable when automatic isolation of the 14 associated RWCU system penetration flow path is credited in calculating drain time. The 15 definition of drain time allows crediting the closing of penetration flow paths that are capable of 16 being automatically isolated by RPV water level isolation instrumentation prior to the RPV water 17 level dropping below the TAF, but if the instrument function is inoperable, a closed path cannot 18 be credited and a drain time calculation must be re-performed. This function is not applicable in 19 MODEs 4 or 5 in TS 3.3.6.1, but is being added to TS 3.3.5.2 to support crediting the automatic 20 isolation of the RWCU system in calculating drain time.

21 22 3.6 OTHER DIFFERENCES BETWEEN THE CURRENT AND PROPOSED TS 23 REQUIREMENTS 24 25 Sections [2.3.3.3 through 2.3.3.5] [NOTE: If there are licensee specific changes, adjust section 26 reference as needed] of this SE describe additional changes to the TSs in which references to 27 OPDRVs are deleted. The NRC staff has determined that deletion of these references is 28 appropriate because the specifications governing Reactor Pressure Vessel Water Inventory 29 Control and associated Instrumentation specifications provide an acceptable alternative set of 30 controls for ensuring water level is maintained above the TAF.

31 32 3.7 TS 3.5.2 - REACTOR PRESSURE VESSEL (RPV) WATER INVENTORY CONTROL 33 REVIEW CONCLUSIONS 34 35 Safety Limit 2.1.1.3 requires that reactor vessel water level shall be greater than the top of 36 active irradiated fuel. Maintaining water level above the TAF ensures that the fuel cladding 37 fission product barrier is protected during shutdown conditions. The changes to the TS 38 establish new LCO requirements that address the preventive and mitigative equipment and 39 associated instrumentation that provide an alternative means to support Safety Limit 2.1.1.3 40 during MODE 4 and 5 operations.

41 42 NOTE: NRC staff shall confirm statements in this paragraph are true for the plant. This 43 information should be available in the plants LAR or FSAR.

44 LOCAs are postulated accidents that would result from the loss of reactor coolant, at a rate in 45 excess of the capability of the normal reactor coolant makeup system, from piping breaks in the 46 reactor coolant pressure boundary. During operation in Modes 4 and 5, the reactor coolant 47 system is at a low operating temperature (<200 degrees Fahrenheit) and is depressurized. An 48 event involving a loss of inventory while in the shutdown condition is judged to not exceed the 49 capacity of one ECCS subsystem. The accidents that are postulated to occur during shutdown 1

conditions, the Fuel Handling Accident and the Waste Gas Decay Tank Rupture, do not involve 2

a loss of inventory. The equipment and instrumentation associated with the Reactor Vessel 3

Water Inventory Control TS do not provide detection or mitigation related to these design basis 4

accidents.

5 6

The revised TS LCO 3.5.2 contains requirements for operability of one ECCS subsystem along 7

with requirements to maintain a sufficiently long drain time that plant operators would have time 8

to diagnose and mitigate an unplanned draining event. The NRC staff has determined that the 9

LCO 3.5.2 and 3.3.5.2 provide for the lowest functional capability or performance levels of 10 equipment required for safe operation of the facility, and therefore, meet the LCO requirements 11 of 10 CFR 50.36(c)(2)(i).

12 13 Additionally, the revised TS LCOs 3.5.2 and 3.3.5.2 provide remedial actions to be taken in the 14 event the LCO is not satisfied, therefore meeting the requirements of 10 CFR 50.36(c)(2)(i).

15 The NRC staff has found that the remedial actions provide reasonable assurance that an 16 unexpected draining event can be prevented or mitigated before the RPV water level would be 17 lowered to the TAF.

18 19 The regulation at 10 CFR 50.36(c)(3) requires TSs to include items in the category of SRs, 20 which are requirements relating to test, calibration, or inspection to assure that the necessary 21 quality of systems and components is maintained, that facility operation will be within safety 22 limits, and that the LCOs will be met. The NRC staff reviewed the SRs associated with the new 23 LCOs 3.5.2 and 3.3.5.2. The NRC staff reviewed the revised SRs and determined that they are 24 appropriate for ensuring the operability of the equipment and instrumentation specified in LCOs 25 3.5.2. Therefore, the NRC staff concludes that the requirements of 10 CFR 50.36(c)(3) are met.

26 27 NOTE: NRC staff shall confirm that the licensee did provide TS Bases consistent with the STS 28 Bases changes approved in TSTF-542 and that the any bracketed information in the STS Bases 29 has been filled in with plant-specific information.

30 The regulation at 10 CFR 50.36(a)(1) states that a summary statement of the bases or reasons 31 for such specifications, other than those covering administrative controls, shall also be included 32 in the application, but shall not become part of the TSs. In accordance with the 10 CFR 33 50.36(a)(1) requirement, the licensee provided TS Bases changes in Attachment 4 of the 34 licensees amendment request. The NRC staff has concluded that the TS Bases changes 35 provided describe the basis for the affected TS and follow the Final Policy Statement on 36 Technical Specifications Improvements for Nuclear Power Reactors (58 Federal Register 37 39132).

38 39 The NRC staffs guidance for review of TSs is in Chapter 16, Technical Specifications, of 40 NUREG-0800, Revision 3, Standard Review Plan (March 2010) (ADAMS Accession 41 No. ML100351425). As described therein, as part of the regulatory standardization effort, the 42 NRC staff has prepared STS for each of the light-water reactor nuclear designs. For BWR/4 43 plants: [NUREG-1433, Revision 4, contains the STS for BWR/4 plants.] For BWR/6 plants:

44

[NUREG 1434, Revision 4, contains the STS for BWR/6 plants.] The changes to the TS 45 were reviewed for technical clarity and consistency with customary terminology and format with 46 the existing requirements. The staff found that the proposed changes were consistent with 47 TSTF-542 and [NUREG-1433] or [NUREG-1434].

48 49 3.8 TECHNICAL CONCLUSION 1

2 The NRC staff evaluated the proposed changes to the TS of proposed drain time definition and 3

TS 3.5.2 related to RPV WIC and TS 3.3.5.2 which contains the instrumentation necessary to 4

support TS 3.5.2. Based on the considerations discussed above, the NRC staff concludes that 5

the proposed revisions to the TS via adding a DRAIN TIME definition and TS 3.5.2 and 6

TS 3.3.5.2 respectively are acceptable.

7 8

NOTE: Include other TS changes as necessary.

9 10

4.0 STATE CONSULTATION

11 12 This section is to be prepared by the PM.

13 14 The requirements with respect to State consultation are contained in 10 CFR 50.91(b). 10 CFR 15 50.91(b)(3) and (b)(4) require that: (1) the NRC make a good faith effort to telephone the State 16 official, prior to amendment issuance, to determine if the State has any comments; and (2) 17 consider any comments of the State official. If there are State comments, they should be 18 addressed in this section. Comments received from members of the public should be addressed 19 within the technical evaluation section or in a separate section of the safety evaluation. See 20 ADAMS Accession No. ML102710156 (Safety Evaluation Section 5.0, Public Comments) for 21 an example of a safety evaluation which addresses public comments.

22 23 In accordance with the Commission's regulations, the [Name of State] State official was notified 24 of the proposed issuance of the amendment. The State official had [no] comments. [If 25 comments were provided, they should be addressed here.]

26 27

5.0 ENVIRONMENTAL CONSIDERATION

28 29 This section is to be prepared by the PM in accordance with current procedures.

30 31

6.0 CONCLUSION

32 33 This section is to be prepared by the PM.

34 35 The Commission has concluded, based on the considerations discussed above, that: (1) there 36 is reasonable assurance that the health and safety of the public will not be endangered by 37 operation in the proposed manner, (2) there is reasonable assurance that such activities will be 38 conducted in compliance with the Commission's regulations, and (3) the issuance of the 39 amendment will not be inimical to the common defense and security or to the health and safety 40 of the public.

41 42

7.0 REFERENCES

43 44 Optional section to be prepared by the PM and primary reviewers. If document is publicly 45 available, the ADAMS Accession No. should be listed.

46 47 Principal Contributor:

48 49 Date: October 6, 2016 1

v t e Letter Sequence Draft Approval
TAC:MF3487, Reactor Pressure Vessel Water Inventory Control (Approved, Closed)
Initiation Request Acceptance Administration Meeting Questions 10 October 2014 18 December 2014 8 December 2015 Answers 15 September 2015 14 March 2016 Results Approval, Approval Other:
MONTHYEAR2015-12-08 [Table View]

ML16250A206

Text

1.0 INTRODUCTION

2.0 REGULATORY EVALUATION

3.0 TECHNICAL EVALUATION

4.0 STATE CONSULTATION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 CONCLUSION

7.0 REFERENCES

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