NG-12-0167, License Amendment Request (TSCR-135): Application for One-Time Technical Specification Change Regarding Core Spray Operability During Shutdown Section Affected: 3.3.5.1: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(Created page by program invented by StriderTol)
Line 1: Line 1:
{{Adams
#REDIRECT [[ML12122A212]]
| number = ML12122A212
| issue date = 05/01/2012
| title = License Amendment Request (TSCR-135): Application for One-Time Technical Specification Change Regarding Core Spray Operability During Shutdown Section Affected: 3.3.5.1
| author name = Wells P
| author affiliation = NextEra Energy Duane Arnold, LLC
| addressee name =
| addressee affiliation = NRC/NRR, NRC/Document Control Desk
| docket = 05000331
| license number = DPR-049
| contact person =
| case reference number = NG-12-0167, TSCR-135
| document type = Letter type:NG, License-Application for (Amend/Renewal/New) for DKT 30, 40, 70
| page count = 26
| project =
| stage = Request
}}
 
=Text=
{{#Wiki_filter:Attachment 1 to NG-12-0167 Page 1 of 12 License Amendment Request (TSCR-135):
Application for One-Time Technical Specification Change Regarding Core Spray Operability during Shutdown; Section Affected:  3.3.
 
==5.1
 
DESCRIPTION==
AND ASSESSMENT
 
1.0
 
==SUMMARY==
DESCRIPTION
 
===2.0 DETAILED===
DESCRIPTION
 
==3.0 TECHNICAL EVALUATION==
 
==4.0 REGULATORY EVALUATION==
 
===4.1 Applicable===
Regula tory Requirements 
 
===4.2 Precedent===
 
4.3 No Significant Hazards Consideration
 
===4.4 Conclusions===
 
==5.0 ENVIRONMENTAL CONSIDERATION==
 
==6.0 REFERENCES==
to NG-12-0167 Page 2 of 12 1.0
 
==SUMMARY==
DESCRIPTION
 
The proposed amendment would revise t he DAEC TS on a one-time basis by adding a note to TS Table 3.3.5.1-1, Func tion 1d, Modes 4 and 5, specifying that Function 1d is not required to be met during RFO 23 in Modes 4 and 5.
 
NextEra Energy Duane Ar nold requests NRC review and approval of the proposed license amendment by October 6, 2012. 
 
===2.0 DETAILED===
DESCRIPTION
 
The proposed amendment would revise t he DAEC TS on a one-time basis by adding a note to TS Table 3.3.5.1-1, Func tion 1d, Modes 4 and 5, specifying that Function 1d is not required to be met during RFO 23 in Modes 4 and 5.
 
NextEra Energy Duane Ar nold has a license renewal commitment for DAEC to re-coat the internal Suppr ession Chamber surface.
During the upcoming Refuel Outage (RFO23), NextEra Energy Duane Arnold plans to fulfill that commitment.
Prior to the discovery of the need for this amendment request, NextEra Energy Duane Arnold had already planned and obtai ned vendor contracts to perform the Suppression Chamber re-coating in RFO
: 23. Therefore, the upcoming RFO 23 is the only practical planned outage w here NextEra Energy Duane Arnold can fulfill this commitment.
 
TS Bases associated with this change will be revised to describe the proposed TS change. Revised Bases pages are attached for information only and do not require NRC approval. The final TS Ba ses pages will be submitted with a future update in accordance with TS 5.5.10, "Technical Specifications (TS) Bases Control Program."  It should be noted that Bases pages B3.3.5.1-109 and B3.5-21 have no changes associated with th is amendment request, but are included for clarity.
 
TS SR 3.5.2.2 specifies the fo llowing must be performed on a Frequency determined by the Surveillance Frequency Control Program:    to NG-12-0167 Page 3 of 12 "Verify, for each required Core Spray (CS) subsystem, the: a. Suppression pool water level is 8.0 ft; or
: b.  -------------
---------NOTE------
-------------------
Only one required CS subsystem may take credit for this option during
 
OPDRVs. [Operations with the Potential for Draining the Reactor Vessel]
 
---------------
---------------
-------------
------------
Condensate storage tank water level in one CST is 11 ft or 7 ft in both CSTs."
When suppression pool level is < 8.0 ft, the CS System is considered OPERABLE only if it can take suction from the Condensate St orage Tank (CST), and the CST water level is sufficient to provide the required NPSH for the CS pump. Therefore, a verification that either the suppression pool water level is  8.0 ft or that CS is aligned to take suction from the CSTs and the CSTs contain  75,000 gallons of water, equivalent to 11 ft in one CST or 7 ft in both CSTs, ensures that the CS System can supply at least 75,000 gallons of makeup water to the RPV. However, as noted, only one required CS subsystem may take credit for the CST option during OPDRVs.
 
During OPDRVs, the volume in the CST may not provide adequate makeup if the
 
Reactor Pressure Vessel (RPV) were co mpletely drained. Therefore, only one CS subsystem is allowed to use the CST. This ensures the other required ECCS subsystem has adequate makeup volume.
 
During the Suppression Chamber re-coat pr oject, all of the water will be removed from the Suppression Cham ber, i.e., there will be no su ppression pool available as an Emergency Core Cooling System (E CCS) suction source for a significant portion of this refueling outage. Because the Residual Heat Removal (RHR) system suction piping cannot be cross-tied to the CSTs, no RHR pumps will be available for satisfying LCO 3.5.2 whenever the Suppression Chamber is drained below the SR 3.5.2.1 requirements (Suppression Pool Level  7ft). Thus, in order to satisfy LCO 3.5.2 during its A pplicability (MODE 4 and MODE 5, except when the cavity level is  21 ft, 1 inch above the RPV flange, with the Spent Fuel Pool gates removed), Next Era Energy Duane Arnold will need to rely exclusively on the CS subsystems for meeting LCO 3.5.2 when the Suppression Chamber is drained. 
 
Additionally, during the Suppression Chamber re-coat project, it is necessary to isolate the CS minimum flow path to the Suppression Chamber to preclude draining of water from the CSTs to the Suppression Chamber during the re-coating process (i.e., the Suppression Cham ber is completely drained to strip off    to NG-12-0167 Page 4 of 12 the existing coating and to re-apply t he new coating, including the curing process). The CS minimum flow valves are "normally open" valves and only close when CS flow > 600 gpm (nominal) is sensed. So, when the CS pump is not running, the minimum flow instrument s send an open signal to the valves. 
 
The current TS requires this minimum flow path to be available in order to maintain the CS subsystems Operable:
 
LCO 3.3.5.1 (ECCS Instrumentation) in Table 3.3.5.1-1, Function 1d, (Core Spray Pump Discharge Flow - Low (Bypass)) requires the CS minimum flow logic to be Operable whenever CS is required to be Operable per LCO 3.5.2 (see footnote a), and  SR 3.5.2.4 also requires the mini mum flow valve to be Operable. 
 
Thus, during the Suppression Chamber re-coat process, i.e., with the suppression pool drained, and both CS subsystems aligned to the CSTs for suction with the minimum flow path secu red, there would be no Operable ECCS subsystems. It should be noted that while both CS subsystems would be declared inoperable, they would be fully f unctional for injection during this time period. Therefore, NextEra Energy Duane Arnold requests the following TS change on a one-time basis:
 
A note is proposed to be added to Table 3.3.5.1-1, Function 1d, Modes 4 and 5, specifying the following:
 
"This requirement is not required to be met during Refueling Outage (RFO) 23."
 
==3.0 TECHNICAL EVALUATION==
 
===3.1 System===
Description
 
The CS System is composed of two independent subsystems. Each subsystem consists of a motor driven pump, a sp ray sparger above the core, and piping and valves to transfer water from the suppr ession pool to the sparger. The CS System is designed to provide cooling to the reactor core when reactor pressure is low. Upon receipt of an initiation si gnal, the CS pumps in both subsystems are automatically started approx imately 5 seconds after AC power is available. When the RPV pressure drops sufficiently, CS System flow to the RPV begins. A full flow test line is provided to route water from and to the suppression pool to allow on-line testing of the CS System without spraying water in the RPV. to NG-12-0167 Page 5 of 12 The CS pumps are provided with minimum flow bypass lines, which discharge to the suppression pool. The valves in t hese lines automatical ly open to prevent pump damage due to overheating when other discharge line valves are closed.
 
The minimum flow instruments are provided to protect the associated low pressure ECCS pump(s) from overheat ing when the pump is operating and the associated injection valve is not fully open. The minimum flow line valves (normally open for the CS System) rece ive an open signal when low flow is sensed, and automatically close when the flow rate is adequate to protect the associated pump. The CS Pump Dischar ge Flow - Low Function is assumed to be OPERABLE and capable of closing the mi nimum flow valves to ensure that the low pressure ECCS flow rates assumed during the transients and accidents analyzed in the Update Final Safety Analysis Report (UFSAR) are met. The core cooling function of the ECCS, along with the scram action of the RPS, ensures that the fuel peak claddi ng temperature remains below the limits of 10 CFR 50.46.
 
One flow switch per CS pump divisi on is used to detect the associated subsystems' flow rates. The logic is a rranged such that each flow switch causes its associated minimum flow valve to receive an open signal. The logic will close the minimum flow valve once the closure setpoint is exceeded. The Pump Discharge Flow - Low Allowable Values are high enough to ensure that the pump flow rate is sufficient to protec t the pump, yet low enough to ensure that the closure of the minimum flow valve is initiated to allow the assumed flow into the core. Each channel of Pump Di scharge Flow - Low Function (two CS channels, one per pump) is only required to be OPERABLE when the CS is
 
required to be OPERABLE to ensure t hat no single instrument failure can preclude the CS function.
 
The purpose of the CS minimum flow logic and associated valve is to protect the pump during initial pump st art-up. When the reactor is at normal operating conditions (MODE 1, 2 and 3), the reactor pressure is higher than the rating of the CS piping outboard of the injection valves. Thus, there is a low pressure permissive for opening the injection valv es (See LCO 3.3.5.1, Table 3.3.5.1, Function 1c). Therefore, there could be some time between the initiation signal for CS pumps to start (L OCA signals) and reactor pressure decaying to below this low pressure injection valve pe rmissive; hence, the need for the minimum flow path to preclude overheating the CS pumps without an available injection pathway (i.e., "dead headed"). Once the in jection valves open, full flow to the Reactor is achieved and the minimum flow logic closes the minimum flow valve to direct all the available CS flow to t he Reactor, as intended. See figure below:
 
to NG-12-0167 Page 6 of 12 CoreSpraySystemSimplifiedDiagram 
 
to NG-12-0167 Page 7 of 12
 
===3.2 Operating===
Experience
 
LER 266/01-005 dated January 28, 2002 from Point Beach (ML020560352) (Reference 1) details misalignment between system design and Emergency Operating Procedures (EOPs). If the Auxiliary Feedw ater System (AFWS) pump discharge or flow control valves were throttled closed with the minimum recirculation valve failed closed, it is possible that the AFW pumps could be placed in a condition of insufficient flow. This could result in pump damage in a short interval of time. The operator s were trained on the significance of maintaining adequate AFW recirculation flow.
However; early in the post reactor trip emergency operating procedures, t he operators were directed to control AFWS flow without specific written guidanc e to maintain mini mum AFW flow. It was postulated that the loss of instrument air together with a common operator response to high steam generator level or overcooling of the Reactor Coolant System (RCS) had some probability to result in failure of one or all of the AFWS pumps.
 
===3.3 Technical===
Evaluation
 
During MODEs 4 and 5, the Reactor is fully depressurized and the low pressure
 
permissive ( 450 psig nominal) for the CS injection valves is always satisfied, i.e., there is virtually no time between the CS initiation signal (low-low-low reactor vessel water level  64" nominal) and injection valv e opening. However, the CS pump starts will be delayed for approximately five (5) seconds (See LCO 3.3.5.1, Function 1e). The purpose of this time delay relay is to st agger the start of the CS pumps that are in each of Divisions 1 and 2, thus limiting the starting transients on the 4.16 kV emergency buses. Based on Inservice Testing (IST) data, the CS injection Motor Operated Valves (MOVs) have a reference stroke time of approximately eight (8) seconds. 
 
Therefore, the injection MOVs will be substantially open prior to the CS pump start to allow full flow to the Reactor and the likelihood of "dead heading" the CS pump is essentially nil. Consequently , there is no functional need for the minimum flow logic and valve(s) to be Operable in these MODES as this pump start sequence poses no risk to pump over heating. With the minimum flow path secured (manual valves closed), there is no diversion of CS away from the Reactor. 
 
Current operating procedure guidance is adequate to ensure the pump is protected from runout conditi ons. Specifically, plant procedures direct "As RPV pressure lowers, throttle INBD IN JECT MO-2117 [MO-2137] valve using handswitch HS-2117 [HS-2137] on 1C03 to maintain <3100 gpm."  Plant procedures will need to be enhanced to ensure a CS pump flow path is    to NG-12-0167 Page 8 of 12 established and flow verified to be  600 gpm immediately following CS initiation and maintained as such during pump operati on. The manual startup / initiation procedure will need to be temporarily re vised to open the INBD INJECT MO-2117 [MO-2137] prior to starting a CS pump in MODES 4 and 5 for RFO 23 only.
Direct indication for CS pump flow is available in Panel 1C03 (refer to the diagram on Page 6). Alte rnate indications for confirming CS pump flow is  600 gpm, such as min-flow valve position which will be available as long as the associated instrumentation remains in se rvice, should be used. If a flow path and required flow rate can not be confirmed, the pump shall prom ptly be secured.
Short duration operation of a CS pump at pump shutoff head (i.e. dead headed), sufficient for the Operators to diagnose the condition and secure the pump, is not detrimental to the pump. However, extended operation beyond a few minutes could cause pump damage.
 
Potential human errors of consequence that could result from this activity are:
: 1. CS Pump damage from prolonged low flow or dead head operation. 2. Diversion of CS injection flow through min-flow line as a result of failure to ensure the line is isolated.
 
Strict administrative and procedural contro ls, operator training, and use of human performance tools will be essential to preventing these types of consequential human errors. Furthermore, both CS subsystems will be guarded and no work or testing will be permitted on either of the CS subsystems during RFO 23 when both CS subsystems are needed to be Oper able to meet the requirements of LCO 3.5.2.
 
NextEra Energy Duan e Arnold also plans to comply with the requirements of EGM-11-003, Enforcement Guidance Memorandum on Dispositioning Boiling Water Reactor Licensee Noncompliance with Technical Specification
 
Containment Requirements dur ing OPDRVs (Reference 2).
 
Conclusion
 
The proposed change and RFO23 strategy to maintain the Core Spray system Operable with the minimum flow line administratively isolated is acceptable and poses no unacceptable risk to nuclear safety or the reliability of the Core Spray system.
 
to NG-12-0167 Page 9 of 12
 
==4.0 REGULATORY EVALUATION==
 
===4.1 Applicable===
Regu latory Requirements
 
10 CFR 50.36 requires in part that the operating license of a nuclear production facility include technical specifications.
Paragraph (c)(2)(ii) of that part requires that a Limiting Condition For Operation (LCO) of a nuclear reactor must be established for each item meeting one or more of four criteria. ECCS Instrumentation identified in LCO 3.3.5.1 me ets Criterion 3, "A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to t he integrity of a fission product barrier."
Paragraph (c)(3) further requires the establishment of Surveillance Requirements, "relating to test, calibration , or inspection to assure ... that the limiting conditions for oper ation will be met."  As discussed above, the proposed one-time change to add a note to TS Tabl e 3.3.5.1-1, Function 1d, Modes 4 and 5, specifying that Function 1d is not r equired to be met during RFO 23 in Modes 4 and 5 is sufficient to demonstrate Operability of the CS Syst em and therefore, are sufficient to ensure t hat the LCO is met. 
 
===4.2 Precedent===
None 4.3 No Significant Hazards Consideration Determination
 
NextEra Energy Duane Ar nold has evaluated whethe r or not a significant hazards consideration is involved with the proposed amendment(s) using the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below: 
: 1)  Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No.
The proposed amendment would revise t he DAEC TS on a one-time basis by adding a note to TS Table 3.3.5.1-1, Function 1d, Modes 4 and 5, specifying that Function 1d is not required to be met during RFO 23 in Modes 4 and 5.
Accidents are initiated by the malf unction of plant equipment, or the catastrophic failure of plant structures, systems, or components.
to NG-12-0167 Page 10 of 12 The low pressure Emergency Core Cooling System (ECCS) subsystems are designed to inject to reflood or to spra y the core after any size break up to and including a design basis Loss of Coolant Accident (LOCA). The proposed change to the Core Spray System Operability requirements does not change the operating configurations or minimum amount of operating equipment assumed in the safety analys is for accident mitigation. The change does not require any change in sa fety analysis methods or results.
Also, it does not change the amount of core spray provided to the core in the accident analyses. No changes are proposed to the manner in which the ECCS provides plant protection or wh ich would create new modes of plant operation. The proposed change does not re sult in any new or affect the probability of any accident initiators.
There will be no d egradation in the performance of, or an increase in the number of challenges imposed on, safety related equipment assumed to function during an accident situation. There will be no change to normal plant operating parameters or accident mitigation performance. This change will only apply when the plant is in MODES 4 and 5 where LOCAs are not postu lated to occur. In MODES 4 and 5, the CS function is to mitigate OPDRVS. Therefor e, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
: 2)  Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No.
This change does not affect the method by which any plant systems perform a safety function. It does not in troduce any new equipment, or hardware changes, which could create a new or di fferent kind of a ccident. No new release pathways or equipment failure mo des are created. No new accident scenarios failure mechanisms or limiting single failures are introduced as a result of this request. This request does not affect the normal methods of plant operation. The Core Spray Syst em retains its ability to function following any accident previously evaluat ed and provide the proper flow rate to the core. This change will only apply when the plant is in MODES 4 and 5
 
where LOCAs are not postulated to o ccur. In MODES 4 and 5, the CS function is to mitigate OPDRVS. Strict administrative and procedural controls, operator training, and use of human performance tools will be essential to preventing these types of consequential human errors. Furthermore, both CS subsystems will be guarded and no work or testing will be permitted on either of the CS subsystems during RFO 23 when both CS subsystems are needed to be Operable to meet the requirement s of LCO 3.5.2.
Therefore, the implementation of the proposed change will not create a possibility for an accident of a new or different type than those previously evaluated. to NG-12-0167 Page 11 of 12
: 3)  Does the proposed amendment involve a significant reduction in a margin of safety?  Response: No.
The ECCS are designed with sufficient redundancy such that if a Core Spray subsystem were unavailable, or did not provide the required flowrate, the remaining Core Spray subsystem is capable of providing water and removing heat loads to satisfy the Updated Final Safety Analysis Report requirements for accident mitigation. A minimum of two low pressure ECCS subsystems continue to be required to be OPERABLE in MODES 4 and 5, except with the spent fuel storage pool gates removed and water level 21 ft 1 inch over the top of the reactor pressure vessel fl ange. There is no change in the Limiting Conditions for Operation.
For these reasons, t he proposed amendment does not involve a significant reduc tion in a margin of safety.
 
Based on the above, Next Era Energy Duane Arnol d concludes that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.
92(c), and, accordingly, a finding of "no significant hazards consideration" is justified. 
 
===4.4 Conclusions===
 
In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed m anner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be in imical to the common defense and security or to the health and safety of the public. 
 
==5.0 ENVIRONMENTAL CONSIDERATION==
 
10 CFR Section 51.22(c)(9) identifies certain licensing and regulatory actions which are eligible for categorical exclusion from the requirement to perform an environmental assessment. A proposed amendment to an operating license for a
 
facility requires no environmental assessm ent if operation of the facility in accordance with the proposed amendment would not: (1) involve a significant hazards consideration; (2) result in a significant change in the types or significant increase in the amounts of any effluents that may be released offsite; and (3) result in a significant increase in indivi dual or cumulative occupational radiation exposure. NextEra Energy Duane Ar nold has reviewed this request and determined that the proposed amendment meets the elig ibility criteria for    to NG-12-0167 Page 12 of 12 categorical exclusion set forth in 10 CFR Section 51.22(c)(9). Pursuant to 10 CFR Section 51.22(b), no env ironmental impact stat ement or environmental assessment needs to be prepared in connection with the issuance of the amendment. The basis for this determination follows:
 
Basis The change meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22(c)(9) for the following reasons:
: 1. As demonstrated in the 10 CFR 50.92 ev aluation included in Section 4.3, the proposed amendment does not involve a significant hazards consideration.
: 2. The proposed change does not result in an increase in power level, do not increase the production, nor alter the fl ow path or method of disposal of radioactive waste or byproducts. There is no significant change in the types or significant increase in the amounts of any effluents that may be released offsite. 
: 3. The proposed change does not result in changes in the level of control or methodology used for processing of radi oactive effluents or handling of solid radioactive waste nor will the proposal result in any change in the normal radiation levels within the plant. There is no significant increase in individual or cumulative occupational radiation exposure.
 
==6.0 REFERENCES==
: 1. LER-266-2001-005, PRA Assessment of Auxiliary Feedwater System Reveals Procedural Vulnerability Related To Loss Of Instrument Air Point Beach Nuclear Plant, Units 1 And 2, dated January 28, 2002 (ML020560352) 2. EGM-11-003, Enforcement Guidance Memorandum on Dispositioning Boiling Water Reactor Licensee Noncompliance with Technical Specification Containment Require ments during Operations with a Potential for Draining the Reac tor Vessel, October 4, 2011 to NG-12-0167 1 page follows
 
Attachment 2
 
TSCR-132  Technical Specification Page (Markups)
ECCS Instrumentation 3.3.5.1  DAEC 3.3-41 TSCR-135 Table 3.3.5.1-1 (page 1 of 5) Emergency Core Cooling System Instrumentation FUNCTION APPLICABLE MODES OR OTHER SPECIFIED CONDITIONS REQUIRED CHANNELS PER FUNCTION CONDITIONS REFERENCED FROM REQUIRED ACTION A.1 SURVEILLANCE REQUIREMENTS ALLOWABLE VALUE
: 1. Core Spray System
: a. Reactor Vessel Water Level - Low Low Low 1,2,3, 4(a), 5(a) 4(b)  B SR  3.3.5.1.1 SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 38.3 inches b. Drywell Pressure -
High 1,2,3 4(b) B SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
< 2.19 psig c. Reactor Steam Dome Pressure - Low (Injection Permissive) 1,2,3  4(a), 5(a) 4  4 C  B SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9 SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 363.3 psig and < 485.1 psig
> 363.3 psig and < 485.1 psig d. Core Spray Pump Discharge Flow - Low (Bypass) 1,2,3, 4(a)*, 5(a)* 1 per pump E SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 256.6 gpm and < 2382.1 gpm e. Core Spray Pump Start Time Delay Relay 1,2,3, 4(a), 5(a) 1 per pump C SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 2.6 seconds and < 6.8 seconds
: f. 4.16 kV Emergency Bus Sequential Loading Relay 1,2,3, 4(a), 5(a) 1 per pump F SR  3.3.5.1.5 SR  3.3.5.1.6 SR  3.3.5.1.9
 
< 3500 V 2. Low Pressure Coolant Injection (LPCI) System
: a. Reactor Vessel Water Level- Low Low Low
 
1,2,3, 4(a), 5(a)      4 
 
B 
 
SR  3.3.5.1.1 SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 38.3 inches
: b. Drywell Pressure -
High  1,2,3  4  B  SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
  < 2.19 psig
 
(continued)
 
(a)  When associated ECCS subsystem(s) are required to be OPERABLE per LCO 3.5.2, ECCS-Shutdown.
 
(b)  Also required to initiate the associated Diesel Generator (DG).
* This requirement is not required to be met during Refueling Outage (RFO) 23.
to NG-12-0167 1 page follows
 
Attachment 3
 
TSCR-132  Technical Specification Page (Clean typed)
 
ECCS Instrumentation 3.3.5.1  DAEC 3.3-41 Amendment Table 3.3.5.1-1 (page 1 of 5) Emergency Core Cooling System Instrumentation FUNCTION APPLICABLE MODES OR OTHER SPECIFIED CONDITIONS REQUIRED CHANNELS PER FUNCTION CONDITIONS REFERENCED FROM REQUIRED ACTION A.1 SURVEILLANCE REQUIREMENTS ALLOWABLE VALUE
: 1. Core Spray System
: a. Reactor Vessel Water Level - Low Low Low 1,2,3, 4(a), 5(a) 4(b)  B SR  3.3.5.1.1 SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 38.3 inches b. Drywell Pressure -
High 1,2,3 4(b) B SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
< 2.19 psig c. Reactor Steam Dome Pressure - Low (Injection Permissive) 1,2,3  4(a), 5(a) 4  4 C  B SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9 SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 363.3 psig and < 485.1 psig
> 363.3 psig and < 485.1 psig d. Core Spray Pump Discharge Flow - Low (Bypass) 1,2,3, 4(a)*, 5(a)* 1 per pump E SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 256.6 gpm and < 2382.1 gpm e. Core Spray Pump Start Time Delay Relay 1,2,3, 4(a), 5(a) 1 per pump C SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 2.6 seconds and < 6.8 seconds
: f. 4.16 kV Emergency Bus Sequential Loading Relay 1,2,3, 4(a), 5(a) 1 per pump F SR  3.3.5.1.5 SR  3.3.5.1.6 SR  3.3.5.1.9
 
< 3500 V 2. Low Pressure Coolant Injection (LPCI) System
: a. Reactor Vessel Water Level- Low Low Low
 
1,2,3, 4(a), 5(a)      4 
 
B 
 
SR  3.3.5.1.1 SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
> 38.3 inches
: b. Drywell Pressure -
High  1,2,3  4  B  SR  3.3.5.1.3 SR  3.3.5.1.8 SR  3.3.5.1.9
 
  < 2.19 psig
 
(continued)
 
(a)  When associated ECCS subsystem(s) are required to be OPERABLE per LCO 3.5.2, ECCS-Shutdown.
 
(b)  Also required to initiate the associated Diesel Generator (DG).
* This requirement is not required to be met during Refueling Outage (RFO) 23.
to NG-12-0167 5 pages follow
 
Attachment 4
 
TSCR-135  Technical Specification BASES pages (Markups)
FOR INFORMATION ONLY ECCS Instrumentation B 3.3.5.1 (continued)
DAEC B 3.3-109  Amendment 223 BASES  APPLICABLE
 
SAFETY
: ANALYSES, LCO, and APPLICABILITY 1.c, 2.c. Reactor Steam Dome Pressure - Low (Injection Permissive)
  (continued)
 
Four channels of Reactor Steam Dome Pressure - Low Function are only required to be OPERABLE when the ECCS is required to be OPERABLE to ensure that no single instrument failure can preclude ECCS initiation. Refe r to LCO 3.5.1 and LCO 3.5.2 for Applicability Bases for the low pressure ECCS  subsystems.
1.d, 2.f. Core Spray and Low Pr essure Coolant Injection Pump Discharge Flow - Low (Bypass)
The minimum flow instruments are provided to protect the associated low pressure ECCS pump(s) from overheating when the pump is operating and the associated injection valve is not fully open. The minimum flow line valves (normally open for the
 
CS System and normally closed for the LPCI System) receive an
 
open signal when low flow is sensed, and automatically close when the flow rate is adequate to protect the associated pump. The LPCI and CS Pump Discharge Flow - Low Functions are
 
assumed to be OPERABLE and c apable of closing the minimum flow valves to ensure that the low pressure ECCS flow rates assumed during the transients and accidents analyzed in References 1, 2, and 3 are met.
The core cooling function of the ECCS, along with the scram action of the RPS, ensures that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.
 
One flow switch per CS pump and one differential pressure switch for the two RHR pumps in each division are used to detect the associated subsystems' flow rates.
The logic is arranged such that each differential pressure swit ch or flow switch causes its associated minimum flow valve to receive an open signal. The logic will close the minimum flow valve once the closure setpoint is exceeded. The LPCI minimum flow valves are time delayed such that the valves will not open for 10 seconds after the
 
switches detect low flow. The time delay is provided by design to limit reactor vessel inventory lo ss during the startup of the RHR shutdown cooling mode although, typically, the minimum flow
 
valves are prevented from openi ng when operating in the shutdown cooling mode. The Pump Discharge Flow - Low
 
Allowable Values are high enough to ensure that the pump flow rate is sufficient to protect the pump, yet low enough to ensure ECCS Instrumentation B 3.3.5.1 (continued)
DAEC B 3.3-110 TSCR-135 BASES  APPLICABLE SAFETY
: ANALYSES, LCO, and APPLICABILITY 1.d, 2.f. Core Spray and Low Pr essure Coolant Injection Pump Discharge Flow-Low (Bypass)
  (continued) that the closure of the minimum flow valve is initiated to allow the assumed flow into the core. Each channel of Pump Discharge
 
Flow - Low Function (two CS channels, one per pump and two LPCI channels, one per loop) is only required to be OPERABLE when the associated ECCS is required to be OPERABLE to
 
ensure that no single instrument failure can preclude the ECCS function. Refer to LCO 3.5.1 and LCO 3.5.2 for Applicability
 
Bases for the low pressure ECCS subsystems.
* 2.d. Reactor Vessel Shroud Level - Low The Reactor Vessel Shroud Level-Low Function is provided as a permissive to allow the RHR System to be manually aligned from
 
the LPCI mode to the suppression pool cooling/spray or drywell spray modes with a LPCI initiati on signal still present. This function ensures:  1) that the permissive is removed prior to
 
reaching two thirds core height when vessel level is decreasing, and 2) that the permissive is not restored until two thirds core height is reached when vessel level is increasing. This ensures
 
that LPCI is available to prevent or minimize fuel damage. This function may be overridden during accident conditions as allowed
 
by plant procedures to allow cont ainment cooling/spray regardless of the level present in the shroud.
Reactor Vessel Shroud Level - Low signals are initiated from
 
four level transmitters that s ense the difference between the pressure due to a constant column of water (reference leg) and the pressure due to the actual wa ter level (variable leg) in the vessel. The Reactor Vessel Shroud Level - Low Allowable
 
Value is chosen to allow the low pressure core flooding systems to activate and provide adequate cooling before allowing a manual transfer.
Four channels of the Reacto r Vessel Shroud Level - Low Function are only required to be OPERABLE in MODES 1, 2, and 3. In MODES 4 and 5, the specified initiati on time of the LPCI subsystems is not assumed, and ot her administrative controls are adequate to control the valves that this Function isolates (since the containment cooling mode of RHR is not required to be OPERABLE in MODES 4 and 5 and is normally not used).
* During Refueling Outage (RFO) 23, the CS minimum flow path is not required to be available for CS to be considered OPERABLE.
 
ECCS - Shutdown B 3.5.2  (continued)
DAEC B 3.5-21 Amendment 223 B 3.5  EMERGENCY CORE COOLING SYSTEMS (ECCS) AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM
 
B 3.5.2  ECCS - Shutdown
 
BASES  BACKGROUND A description of the Core Spra y (CS) System is provided in the Bases for LCO 3.5.1, "ECCS-Operating".
 
The Low Pressure Coolant Injecti on (LPCI) Mode of the Residual Heat Removal (RHR) System, for the application of this specification, takes on a differ ent definition than is described in the Bases for LCO 3.5.1 "ECCS-Oper ating". In the application of "ECCS-Shutdown", the low pressure ECCS subsystems consist of two CS subsystems and two LPCI subsystems. Each LPCI
 
subsystem consists of one moto r driven RHR pump, piping, and valves to transfer water from t he suppression pool to the Reactor Pressure Vessel (RPV). Only a single RHR pump is required per subsystem because of the larger in jection capacity in relation to a CS subsystem.
APPLICABLE SAFETY ANALYSES The ECCS performance is evaluated for the entire spectrum of break sizes for a postulated Loss of Coolant Accident (LOCA).
The long term cooling analysis following a design basis LOCA (Ref. 1) demonstrates that only one low pressure ECCS pump is required, post LOCA, to mainta in adequate reactor vessel water level. It is reasonable to assume, based on engineering judgement, that while in MODES 4 and 5, one low pressure ECCS subsystem can maintain adequate reactor vessel water level. To
 
provide redundancy, a minimum of two low pressure ECCS subsystems are required to be OPERABLE in MODES 4 and 5.
 
The low pressure ECCS subsystem s satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO Two low pressure ECCS subsystems are required to be OPERABLE. For this specification, the low pressure ECCS subsystems consist of two CS subsystems and two LPCI
 
subsystems. Each CS subsystem consists of one motor driven pump, piping, and valves to trans fer water from the suppression pool or Condensate Storage Tank (C ST) to the Reactor Pressure ECCS - Shutdown B 3.5.2  (continued)
DAEC B 3.5-22 TSCR-135 BASES  LCO (continued)
Vessel (RPV)
*. Each LPCI subsystem consists of one motor driven RHR pump, piping, and valves to transfer water from the suppression pool to the RPV. Only a single RHR pump is required per subsystem because of t he larger injection capacity in relation to a CS subsystem. In MODES 4 and 5, the RHR System cross tie valve is not required to be open. The necessary portions
 
of Emergency Service Water are also required to provide
 
appropriate cooling to each required CS subsystem. One LPCI subsystem may be aligned for decay heat removal and 
 
considered OPERABLE for the E CCS function, if it can be manually realigned (remote or local) to the LPCI mode and is not otherwise inoperable. Because of low pressure and low temperature conditions in MODES 4 and 5, sufficient time will be available to manually align and initiate LPCI subsystem operation to provide core cooling prior to postulated fuel uncovery.
APPLICABILITY OPERABILITY of the low pr essure ECCS subsystems is required in MODES 4 and 5 to ensure ad equate coolant inventory and sufficient heat removal capability for the irradiated fuel in the core in case of an inadvertent draindown of the vessel. Requirements for ECCS OPERABILITY during MODES 1, 2, and 3 are
 
discussed in the Applicability sectio n of the Bases for LCO 3.5.1.
ECCS subsystems are not requi red to be OPERABLE during MODE 5 with the spent fuel storage pool gates removed and the water level maintained at  21 ft 1 inch above the RPV flange.
This provides sufficient coolant inventory to allow operator action to terminate the inventory loss prior to fuel uncover in case of an inadvertent draindown.
 
The Automatic Depressurization System is not required to be OPERABLE during MODES 4 and 5 because the RPV pressure is  100 psig, and the CS and LPCI subsystems can provide core cooling without any depressuriza tion of the primary system.
 
The High Pressure Coolant Injecti on System is not required to be OPERABLE during MODES 4 and 5 since the low pressure ECCS
 
subsystems can provide sufficient flow to the vessel and because insufficient reactor pressure is ava ilable to drive the HPCI turbine.
* During Refueling Outage (RFO) 23, the CS minimum flow path is not required to be available for CS to be considered OPERABLE.
 
ECCS - Shutdown B 3.5.2  (continued)
DAEC B 3.5-25 TSCR-135 BASES  SURVEILLANCE REQUIREMENTS SR  3.5.2.1 and SR  3.5.2.2 (continued)
When suppression pool level is
< 8.0 ft, the CS System is considered OPERABLE only if it c an take suction from the CST, and the CST water level is sufficient to provide the required NPSH
 
for the CS pump. Therefore, a verification that either the suppression pool water level is  8.0 ft or that CS is aligned to take suction from the CSTs and the CSTs contain  75,000 gallons of water, equivalent to 11 ft in one CST or  7 ft in both CSTs, ensures that the CS System can supply at least 75,000 gallons of makeup water to the RPV. However, as noted, only one required CS subsystem may take credit for the CST option during OPDRVs. During OP DRVs, the volume in the CST may not provide adequate makeup if the RPV were completely drained. Therefore, only one CS subsystem is allowed to use the CST. This ensures the other required ECCS subsystem has
 
adequate makeup volume.
The Surveillance Frequency is controlled under the Surveillance
 
Frequency Control Program. The Frequency of these SRs was developed considering operati ng experience related to suppression pool water level and CST water level variations
 
during the applicable MODES.
Furthermore, the Frequency is considered adequate in view of other indications available in the control room to alert the operator to an abnormal suppression pool or CST water level condition.
SR  3.5.2.3, SR  3.
5.2.5, and SR  3.5.2.6 The Bases provided for SR 3.5.1.
1, SR 3.5.1.4, and SR 3.5.1.7 are applicable to SR 3.5.2.3, SR 3.5.2.5, and SR 3.5.2.6, respectively.
SR  3.5.2.4 Verifying the correct alignment for power operated and automatic valves in the ECCS flow paths provides assurance that the proper flow paths will exist for ECCS operation.
* This SR does not apply to valves that are locked, sealed, or otherwise secured in position, since these valves were verified to be in the correct position prior to locking, sealing, or securing. A valve that receives an initiation signal is allowed to be in a nonaccident position provided the
* During Refueling Outage (RFO) 23, the CS minimum flow path is not required to be available for CS to be considered OPERABLE
. to NG-12-0167 Page 1 of 2
 
Attachment 5 TSCR-135  Commitment    to NG-12-0167 Page 2 of 2 Commitment
: 1. NextEra Energy Duane Arnold will guard both CS subsystems and will not perform any work or testing on either of the CS subsystems during RFO 23 when both CS subsystems are needed to be Operable to meet the
 
requirements of LCO 3.5.2.}}

Revision as of 00:46, 30 April 2019

Redirect to:

Retrieved from "https://kanterella.com/w/index.php?title=NG-12-0167,_License_Amendment_Request_(TSCR-135):_Application_for_One-Time_Technical_Specification_Change_Regarding_Core_Spray_Operability_During_Shutdown_Section_Affected:_3.3.5.1&oldid=1551603"