CNS-14-026, Exigent License Amendment Request (LAR) to Revise Technical Specification (TS) 3.3.4, Remote Shutdown System.

Exigent License Amendment Request (LAR) to Revise Technical Specification (TS) 3.3.4, Remote Shutdown System.

ML14050A346
Person / Time
Site:	Catawba
Issue date:	02/17/2014
From:	Henderson K Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNS-14-026
Download: ML14050A346 (15)

Text

Kelvin Henderson 4DUKE Vice President ENERGY Catawba Nuclear Station Duke Energy CNO1VP 1 4800 Concord Road CNS-14-026 York, SC 29745 o: 803.701.4251 February 17, 2014 10 CFR 50.90 f: 803.701.3221 10 CFR 50.91(a)(6)

U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001

Subject:

Duke Energy Carolinas, LLC (Duke Energy)

Catawba Nuclear Station, Units 1 and 2; Docket Nos. 50-413 and 50-414 Exigent License Amendment Request (LAR) to Revise Technical Specification (TS) 3.3.4, "Remote Shutdown System" In accordance with the provisions of 10 CFR 50.90 and 10 CFR 50.91(a)(6), Duke Energy is submitting an exigent LAR for Catawba Nuclear Station, Units 1 and 2. Although the specifics of the LAR only involve Unit 2, this LAR is being docketed for both units since Unit 1 and Unit 2 utilize common TS. Specifically, Duke Energy requests NRC review and approval of a proposed change to TS 3.3.4 as a result of an inoperable instrumentation function on Unit 2.

Table 3.3.4-1, "Remote Shutdown System Instrumentation and Controls" specifies requirements for Function 3.b., Decay Heat Removal via Steam Generators (SGs) - Reactor Coolant System (RCS) Cold Leg Temperature - Loop A and B as "1 per loop". Loop A of this function is presently inoperable on Unit 2 due to a failed resistance temperature detector (RTD). Loop B of this function is operable with a reliable maintenance history. The failed RTD on Loop A cannot be replaced in the present operating mode of Unit 2 (Mode 1). Therefore, Duke Energy is requesting NRC approval of this LAR to allow Unit 2 to remain in Mode 1 until such time that the failed RTD can be replaced. The replacement would occur in the next refueling outage or the next outage that would facilitate replacement, whichever occurs first.

Enclosure 1 provides Duke Energy's evaluation of the LAR which contains a description of the proposed changes, the technical analysis, the determination that this LAR contains No Significant Hazards Consideration, and the basis for the categorical exclusion from performing an Environmental Assessment/Impact Statement.

Duke Energy is requesting that the NRC review and approve this LAR on an exigent basis in accordance with 10 CFR 50.91(a)(6). Enclosure 1 contains a discussion as to the exigent nature of this submittal and why the exigent circumstances are necessitated. Duke Energy is requesting NRC approval of this LAR no later than February 26, 2014. RCS Cold Leg Temperature - Loop A must be restored to operable status by March 2, 2014 at 0918 hours0.0106 days <br />0.255 hours <br />0.00152 weeks <br />3.49299e-4 months <br />.

The target date for implementation of the approved amendments is February 27, 2014. Absent NRC approval of this request, a TS required Unit 2 shutdown would need to commence on March 2, 2014 at 0918 hours0.0106 days <br />0.255 hours <br />0.00152 weeks <br />3.49299e-4 months <br />.

www.duke-energy.com

U.S. Nuclear Regulatory Commission Page 2 February 17, 2014 Future revision to the Catawba Updated Final Safety Analysis Report (UFSAR) necessary to reflect approval of this LAR will be made in accordance with 10 CFR 50.71(e).

In accordance with Duke Energy administrative procedures and the Quality Assurance Program Topical Report, this LAR has been previously reviewed and approved by the Catawba Plant Operations Review Committee.

Pursuant to 10 CFR 50.91, a copy of this LAR has been forwarded to the appropriate State of South Carolina official.

There are no regulatory commitments contained in this letter or its enclosure.

If you have any questions or need additional information on this matter, please contact L.J.

Rudy at (803) 701-3084.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on February 17, 2014.

Very truly yours, Kelvin Henderson Vice President, Catawba Nuclear Station LJR/s Enclosure

U.S. Nuclear Regulatory Commission Page 3 February 17, 2014 xc (with enclosure):

V.M. McCree Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 G.A. Hutto, III Senior Resident Inspector (Catawba)

U.S. Nuclear Regulatory Commission Catawba Nuclear Station J.C. Paige (addressee only)

NRC Project Manager (Catawba)

U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 8 G9A 11555 Rockville Pike Rockville, MD 20852-2738 S.E. Jenkins Manager Radioactive & Infectious Waste Management Division of Waste Management South Carolina Department of Health and Environmental Control 2600 Bull St.

Columbia, SC 29201

Enclosure LICENSEE EVALUATION

Subject:

Exigent License Amendment Request (LAR) to Revise Technical Specification (TS) 3.3.4, "Remote Shutdown System" 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 Significant Hazards Consideration 4.4 Conclusions

5.0 ENVIRONMENTAL CONSIDERATION

Page 1 of 9

Enclosure LICENSEE EVALUATION 1.0

SUMMARY

DESCRIPTION This evaluation supports a request to amend TS 3.3.4, "Remote Shutdown System" as a result of an inoperable instrumentation function on Unit 2.

Table 3.3.4-1, "Remote Shutdown System Instrumentation and Controls" specifies requirements for Function 3.b., Decay Heat Removal via Steam Generators (SGs) - Reactor Coolant System (RCS) Cold Leg Temperature - Loop A and B as "1 per loop". Loop A of this function is presently inoperable on Unit 2 due to a failed resistance temperature detector (RTD). Loop B of this function is operable with a reliable maintenance history. The failed RTD on Loop A cannot be replaced in the present operating mode of Unit 2 (Mode 1). Therefore, Duke Energy is requesting NRC approval of this LAR to allow Unit 2 to remain in Mode 1 until such time that the failed RTD can be replaced. The replacement would occur in the next refueling outage or the next outage that would facilitate replacement, whichever occurs first.

2.0 DETAILED DESCRIPTION The Remote Shutdown System provides the control room operator with sufficient instrumentation and controls to place and maintain the unit in a safe shutdown condition from a location other than the control room. This capability is necessary to protect against the possibility that the control room becomes inaccessible. A safe shutdown condition is defined as Mode 3. With the unit in Mode 3, the Auxiliary Feedwater (AFW) System and the SG safety valves or the SG power operated relief valves (PORVs) can be used to remove core decay heat and meet all safety requirements. The long term supply of water for the AFW System and the ability to borate the RCS from outside the control room allows extended operation in Mode 3.

If the control room becomes inaccessible, the operators can establish control at the remote shutdown panel, and place and maintain the unit in Mode 3. Not all controls and necessary transfer switches are located at the remote shutdown panel. Some controls and transfer switches will have to be operated locally at the switchgear, motor control panels, or other local stations. The unit automatically reaches Mode 3 following a unit shutdown and can be maintained safely in Mode 3 for an extended period of time.

The operability of the remote shutdown control and instrumentation functions ensures there is sufficient information available on selected unit parameters to place and maintain the unit in Mode 3 should the control room become inaccessible.

As indicated above, the failed instrument is the RTD associated with RCS Cold Leg Temperature - Loop A (Loop B is presently operable). The equipment identifier for this component is 2NCRD5860. This RTD is a dual-element Conax Model 7D56-10000. The 7D56-10000 is a fast-response, unitized RTD assembly consisting of an RTD probe, a spring-loaded adapter, and armored nuclear grade cabling. Each element consists of a platinum temperature detector with monofilament wires on each side of the RTD capable of indicating from 32°F (1000) to 700OF (2370). The end of each monofilament wire is connected to a pair of leads to provide redundancy in the event one of the leads fails.

2NCRD5860 has been assigned to the 1 through 4 leads (cables 2*NC962 and 2*NC685) on the dual-element RTD. The remaining 5-8 leads can be utilized as an installed spare, and the wires have been coiled up and stored for usage inside containment. Leads 1 (2RD5860A) and Page 2 of 9

Enclosure 2 (2RD5860B) connect to one of the monofilament wires, while leads 3 (2RD5860C) and 4 (2RD5860D) connect to the other monofilament wire. All four leads travel from the RTD enclosure through containment penetration 2PENT0222.

After leaving the containment penetration, the four leads are routed through conduit to the Unit 2 AFW pump room to 2TBOX0400. The leads are terminated to sliding links DD-1 through DD-4 in 2TBOX0400. From there, they proceed to Amphenol plug P2 in 2TBOX0400. In normal plant operation, plug P2 is connected to receptacle R4 which transmits the temperature signal to the control room. While aligned to the control room, the signal provides indication to control board gauge 2NCP5860, Operator Aid Computer point C2A0700, and chart recorder 2NCCR5860.

When the control room is evacuated per procedure API2/A/5500/017, "Loss of Control Room",

plug P2 is removed from receptacle R4 and connected to receptacle R3. This will transmit the temperature signal to remote shutdown panel A. The signal can be read on gauge 2NCP5861.

The signal is also sent to a "Low Pressure Mode" light at the panel, which is actuated when RCS Cold Leg Temperature - Loop A falls below 300°F to assist in plant cooldown.

TS Limiting Condition for Operation (LCO) 3.3.4 requires the Remote Shutdown System functions in Table 3.3.4-1 to be operable in Modes 1, 2, and 3. With one or more required functions inoperable (Condition A), the required function(s) must be restored to operable status within 30 days (Required Action A.1). With this Required Action and associated Completion Time not met (Condition B), the unit must be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (Required Action B.1) and in Mode 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (Required Action B.2).

RCS Cold Leg Temperature is also an instrumentation function required by TS 3.3.3, "Post Accident Monitoring (PAM) Instrumentation". However, the inoperability of RCS Cold Leg Temperature - Loop A by itself does not require the unit to enter a TS Condition necessitating a unit shutdown per TS 3.3.3. It requires the submission of a PAM Report pursuant to TS 5.6.7.

Therefore, no relief is needed or is being requested from TS 3.3.3.

Description of Proposed TS Change Function 3.b. of Table 3.3.4-1 is proposed to be modified by placing the following footnote:

3.b. RCS Cold Leg Temperature - Loop A* and B

• For Unit 2 only, Loop A of this Function is not required to be operable until such time that its associated resistance temperature detector (RTD) can be replaced either during the Cycle 20 Refueling Outage or another outage that facilitates replacement, whichever occurs first.

The Unit 2 Cycle 20 Refueling Outage is scheduled for Spring 2015.

The marked-up and reprinted TS pages are contained in this submittal at the end of this enclosure.

No changes to the TS Bases are necessary in conjunction with this LAR.

Page 3 of 9

Enclosure

3.0 TECHNICAL EVALUATION

Regarding the need for an exigent request, the circumstances leading to the exigency were unforeseen. The failed RTD could not have been anticipated. There was no adverse maintenance history concerning this component. This Remote Shutdown System function had previously passed its required TS surveillance and other required testing. On January 31, 2014, the Unit 2 RCS Cold Leg Temperature - Loop A was declared inoperable to perform periodic TS required calibration. Following the calibration, but before the function could be declared operable, erratic indications were observed and troubleshooting activities were initiated to determine the cause of the erratic indications. After extensive troubleshooting, it was determined on February 14, 2014 that the loop RTD had failed and required replacement, which would necessitate a unit shutdown. The following timeline identifies key points between January 31 and February 14:

1/31/14 - Unit 2 RCS Cold Leg Temperature - Loop A was declared inoperable at 0918 hours0.0106 days <br />0.255 hours <br />0.00152 weeks <br />3.49299e-4 months <br /> due to required calibration per work order 02098565. There were no known issues following the calibration and all indications were normal; however, a functional check still needed to be performed.

2/3/14 - Monthly performance test ( the functional check) was scheduled but was not performed due to erratic indications in the control room. Work order 02098565 remained open.

Maintenance was first engaged regarding the indications on this function. The work was made an emergent priority commensurate with the TS 30-day Required Action.

2/5/14 - Problem Investigation Process (PIP) C-14-01307 was written for 2NCP5860 erratic indication. Work request 1103614 was written to troubleshoot the continued erratic indication.

2/7-8/14 - Monthly performance test was performed per PT/2/AI4600/003 A, "Monthly Surveillance Items". The acceptance criterion was not met for this function. PIP C-14-01432 was written.

2/10-11/14 - Work request 1103614 was upgraded to highest priority for completion within 7 days. Work request 1103614 was planned to work order 2139323. Maintenance performed initial troubleshooting of this function. Initial indications were inconclusive as to the exact problem. Maintenance and Engineering developed further troubleshooting instructions.

2/12/14 - Maintenance could not perform further troubleshooting activities on this function because of other ongoing plant activities.

2/13/14 - A winter storm resulted in a significant shortage of manpower to perform troubleshooting activities.

2/14/14 - Maintenance determined that this function's RTD had failed and needed to be replaced. The failed RTD could not have been anticipated. At this point, the decision was made to pursue a LAR on an exigent basis.

This failure, and the subsequent need for a TS change, could not have been anticipated, as the function had passed its previous TS required surveillance testing (channel check on January 9, 2014 and channel calibration on May 30, 2012). A review of the maintenance history for this RTD did not reveal any previous problems with it. Therefore, this failure could not have been anticipated and this LAR meets the criteria for an exigent request.

Page 4 of 9

Enclosure In support of this exigent request, a review of Operations procedures has been performed to ascertain the impact of the inoperable function. The impact is as follows:

Identify where in Emergency Procedures (EPs) and Abnormal Procedures (APs) the indication is used. Identify what alternate indication is available in place of this instrument.

2NCP5860 (control room gauge) is not specifically used in any EP/AP. However, the following procedures could use 2NCP5861 (Remote Shutdown System gauge):

AP121A15500/017, "Loss of Control Room" Auxiliary Shutdown Panel (ASP) operator actions references T-Cold indication at the ASP when controlling RCS temperature.

When using this indication, the procedure gives the option of T-Cold indication or SG pressure.

EPI2/AI5000IES-0.2, "Natural Circulation Cooldown" has the operator verify all RCS wide-range temperatures less than 200°F prior to removing containment spray and safety injection from standby readiness. Other loop temperatures or the Operator Aid Computer could be used for this indication.

Temperature control guidance from other EPs require T-Cold indication when in natural circulation, but other loop T-Colds and Operator Aid Computer indication can be used.

OP/2/AI61001020, "Shutdown Outside the Control Room Following Fire" uses T-Cold -

near saturation temperature for SG pressures when verifying natural circulation, but the operator can alternatively use core exit thermocouples and T-Hot - stable or decreasing.

OP121AI61001004, "Achieving Cold Shutdown From Outside the Control Room" uses RCS T-Cold indication as guidance for low temperature overpressure protection.

Indication from the opposite train ASP would need to be relied on given the inoperable function.

• Identify any additional training that may be necessary related to these changes.

No additional training is required due to alternate indications of cold leg temperatures.

Therefore, based on the diversity of RCS temperature indication available to plant operators, redundant indication will be available to respond to any plant event that may require the use of the Remote Shutdown System.

This request has been reviewed from a probabilistic risk analysis (PRA) perspective. It should be noted that this LAR is not being submitted as a risk-based LAR. The LAR is being submitted as a deterministic LAR with risk insights.

The risk of extended plant operation with the inoperable function out of service is qualitatively assessed to be very low. Except as specifically indicated above, the wide-range cold leg temperature instrumentation is not used for any control room actions in any EPs or APs.

Operator actions at the ASP reference T-Cold indication at the ASP when controlling RCS temperature. The ASP is used in the event of a control room evacuation, but local operator Page 5 of 9

Enclosure action is required to swap terminal plugs so that these RTDs can be read from the ASP. The procedure gives the operator the option of using T-Cold indication or SG pressure indication.

This instrumentation is not modeled in the Catawba PRA or in the Catawba Fire PRA since it does not support accident mitigation systems or operator actions credited in the PRA. The likelihood of a control room evacuation scenario which might use this instrumentation is very low. The associated operator actions at the ASP are not significantly impacted by the unavailability of a single T-Cold loop, since the other loop is indicated on the adjacent panel and SG pressure indication can also be used. Operations has been briefed on the inoperable function and has been instructed not to rely on this indication. The Standby Shutdown System (SSS) is the primary means of maintaining safe shutdown conditions for control room fire scenarios rather than the ASP, and the SSS does not rely on the same instrument loops for RCS temperature monitoring. Therefore, it is concluded that extended plant operation with an inoperable wide-range T-Cold indication loop constitutes a very low risk based on 1) a very low probability event requiring this indication and 2) the availability of redundant equipment and alternate means of monitoring RCS system temperatures.

No changes will be required to the Catawba Emergency Plan, Fire Plan, or Security Plan as a result of this request.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria The criteria governing the design and specific system requirements of the Remote Shutdown System are located in 10 CFR 50, Appendix A, General Design Criterion 19, Control Room. This LAR is being submitted in accordance with 10 CFR 50.90.

4.2 Precedent A search of the NRC's Agencywide Documents Access and Management System (ADAMS) revealed a similar exigent request for license amendment to the NRC. Reference letter from Chandu P. Patel, NRC to Karl W. Singer, Tennessee Valley Authority, "Watts Bar Unit 1 - Issuance of Exigent Technical Specification Amendment Concerning Inoperable Reactor Coolant System Temperature Indicator (TAC No. MC4979)", dated November 19, 2004 (ADAMS Accession Number ML043140476). This amendment provided a one-time change to Function 4a, "Reactor Coolant System (RCS) Hot Leg Temperature Indication", of TS Table 3.3.4-1. Specifically, this amendment allowed the Loop 4 RCS hot leg temperature indicator in the Auxiliary Control Room to be inoperable for the remainder of Cycle 6, which was scheduled to end at the conclusion of the spring 2005 refueling outage.

4.3 Significant Hazards Consideration Duke Energy has evaluated whether or not a significant hazards consideration is involved with the proposed amendments by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

Page 6 of 9

Enclosure

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

Response: No.

The proposed amendments do not affect the probability of any accident occurring since the Remote Shutdown System is not an accident initiator or a precursor to the initiation of any analyzed accident. Therefore, there can be no increase in the probability of any accident occurring. The Remote Shutdown System functions to provide an auxiliary means to shut down the unit should the control room become inoperable or uninhabitable. Procedural guidance will ensure that plant operators can compensate for the inoperable Remote Shutdown System function (Reactor Coolant System Cold Leg Temperature -

Loop A) while this license amendment is in effect. The risk of extended plant operation with the inoperable function out of service was qualitatively assessed to be low. In addition, the proposed amendments will not affect the performance of any other plant equipment used to mitigate the consequences of an analyzed accident. There will be no significant impact on the source term or pathways assumed in accidents previously evaluated. No analysis assumptions will be violated and there will be no adverse effects on offsite or onsite dose as the result of an accident.

Therefore, the proposed amendments do 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.

The proposed amendments do not change the methods governing normal plant operation; nor are the methods utilized to respond to plant transients and accidents altered. Procedural guidance will ensure that plant operators appropriately respond to transients and accidents even with the inoperable Remote Shutdown System function. In addition, the proposed amendments will not create the potential for any new initiating transients or accidents to occur in the actual physical plant.

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

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

Response: No.

Margin of safety is related to the confidence in the ability of the fission product barriers to perform their design functions during and following an accident.

These barriers include the fuel cladding, the Reactor Coolant System, and the containment system. The proposed amendments will not challenge the acceptability of any analytical limits under normal, transient, and accident Page 7 of 9

Enclosure conditions. All applicable design and safety limits will continue to remain satisfied such that the fission product barriers will continue to perform their design functions.

Therefore, the proposed amendments do not involve a significant reduction in a margin of safety.

Based on the preceding discussion, Duke Energy concludes that the proposed amendments do 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 manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

5.0 ENVIRONMENTAL CONSIDERATION

Pursuant to 10 CFR 51.22(b), an evaluation of this license amendment request has been performed to determine whether or not it meets the criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) of the regulations. Implementation of this amendment will have no adverse impact upon the Catawba units; neither will it contribute to any additional quantity or type of effluent being available for adverse environmental impact or personnel exposure.

It has been determined there is:

1. No significant hazards consideration;

2. No significant change in the types or significant increase in the amounts of any effluents that may be released offsite; and

3. No significant increase in individual or cumulative occupational radiation exposure.

Therefore, these proposed amendments to the Catawba Nuclear Station TS meet the criteria of 10 CFR 51.22(c)(9) for categorical exclusion from an environmental impact statement.

Page 8 of 9

Enclosure Marked-Up and Reprinted TS Pages Page 9 of 9

Remote Shutdown System 3.3.4 Table 3.3.4-1 (page 1 of 1)

Remote Shutdown System Instrumentation and Controls FUNCTION/INSTRUMENT REQUIRED OR CONTROL PARAMETER NUMBER OF FUNCTIONS Reactivity Control

a. Reactor Trip Breaker Position 1 per trip breaker

2. Reactor Coolant System (RCS) Pressure Control

a. Pressurizer Pressure

3. Decay Heat Removal via Steam Generators (SGs) 1 per loop

a. RCS Hot Leg Temperature - Loop A and B 1 per loop

b. RCS Cold Leg Temperature - Loop A and B 1 per SG

c. SG Pressure 1 per SG

d. SG Level or AFW Flow 1IeS

4. RCS Inventory Control

a. Pressurizer Level

• -, (5-ce, f\eýý-t Faii-)

Catawba Units 1 and 2 3.3.4-3 Amendment Nos. 6T)

INSERT

• For Unit 2 only, Loop A of this Function is not required to be operable until such time that its associated resistance temperature detector (RTD) can be replaced either during the Cycle 20 Refueling Outage or another outage that facilitates replacement, whichever occurs first.

Remote Shutdown System 3.3.4 Table 3.3.4-1 (page 1 of 1)

Remote Shutdown System Instrumentation and Controls FUNCTION/INSTRUMENT REQUIRED OR CONTROL PARAMETER NUMBER OF FUNCTIONS

1. Reactivity Control

a. Reactor Trip Breaker Position 1 per trip breaker

2. Reactor Coolant System (RCS) Pressure Control

a. Pressurizer Pressure

3. Decay Heat Removal via Steam Generators (SGs)

a. RCS Hot Leg Temperature - Loop A 1 per loop and B

b. RCS Cold Leg Temperature - Loop A* 1 per loop and B

c. SG Pressure 1 per SG

d. SG Level 1 per SG or AFW Flow

4. RCS Inventory Control

a. Pressurizer Level For Unit 2 only, Loop A of this Function is not required to be operable until such time that its associated resistance temperature detector (RTD) can be replaced either during the Cycle 20 Refueling Outage or another outage that facilitates replacement, whichever occurs first.

Catawba Units 1 and 2 3.3.4-3 Amendment Nos.