L-PI-13-061, Supplement to License Amendment Request (LAR) to Revise Technical Specification (TS) 3.5.3, ECCS (Emergency Core Cooling System) - Shutdown.

Supplement to License Amendment Request (LAR) to Revise Technical Specification (TS) 3.5.3, ECCS (Emergency Core Cooling System) - Shutdown.

ML13178A024
Person / Time
Site:	Prairie Island
Issue date:	06/25/2013
From:	Jeffery Lynch Northern States Power Co, Xcel Energy
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-PI-13-061, TAC MF0727, TAC MF0728
Download: ML13178A024 (5)

Text

Xcel Energy L-PI-13-061 10 CFR 50.90 JUN 2 5. 2013 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Units 1 and 2 Dockets 50-282 and 50-306 Renewed License Nos. DPR-42 and DPR-60 Supplement to License Amendment Request (LAR) to Revise Technical Specification (TS) 3.5.3, "ECCS [Emergency Core Cooling System]- Shutdown" (TAC Nos. MF0727 and MF0728)

By letter dated February 20, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13053A199), Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), submitted a license amendment request for Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2, to remove Technical Specification (TS) 3.5.3 Limiting Condition for Operation (LCO) Note 1. By email dated May 29, 2013, NRC Staff requested additional information (RAI) on the February 20, 2013, LAR (ML13053A199). The enclosure to this letter provides the response to the NRC Staff request for information. NSPM submits this supplement in accordance with the provisions of 10 CFR 50.90.

The supplemental information provided in the enclosure to this letter modifies the Determination of No Significant Hazards Consideration. However, the revised Determination of No Significant Hazards Consideration does not change the conclusions of the Determination of No Significant Hazards Consideration or Environmental Assessment presented in the February 20, 2013, (ML13053A199) submittal.

In accordance with 10 CFR 50.91, NSPM is notifying the State of Minnesota of this LAR supplement by transmitting a copy of this letter and enclosure to the designated State Official.

If there are any questions or if additional information is needed, please contact Mr. Dale Vincent, P.E., at 651-388-1121.

1717 Wakonade Drive East

• Welch, Minnesota 55089-9642 Telephone: 651.388.1121

Document Control Desk Page 2 Summary of Commitments This letter contains no new commitments and no revisions to existing commitments.

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

Executed on /.:z )3 6 S J,~~~

Site Vice President, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota Enclosures (1) cc: Administrator, Region Ill, USNRC Project Manager, PINGP, USNRC Resident Inspector, PINGP, USNRC State of Minnesota

ENCLOSURE Supplement to License Amendment Request (LAR) to Revise Technical Specification (TS) 3.5.3, "ECCS [Emergency Core Cooling System] - Shutdown" TAC Nos. MF0727 and MF0728 By letter dated February 20, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13053A199), Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), submitted a license amendment request for Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2, to remove Technical Specification (TS) 3.5.3 Limiting Condition for Operation (LCO) Note 1. By email dated May 29, 2013, NRC Staff requested additional information on the February 20, 2013, LAR (ML13053A199).

NRC Request for Additional Information (RAil:

In Question 1 of Section 4.3, "Significant Hazards Consideration," of the February 20, 2013, submittal, the licensee provided the following statement, in part:

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

Response: No The ECCS [emergency core cooling system] and RHR [residual heat removal]

subsystem are not accident initiators and therefore the proposed removal of the LCO note does not involve an increase in the probability of an accident.

Please explain this statement in light of incidents that have occurred that were initiated by operator error, such as inappropriate valve manipulations.

NSPM Response:

License amendment requests are required to address question (1) in 10 CFR 50.92(c) which asks if the change would "Involve a significant increase in the probability or consequences of an accident previously evaluated". The NRC provided guidance for addressing 10 CFR 50.92(c) in Attachment 1 to RIS 2001-022, "Attributes of a Proposed No Significant Hazards Consideration Determination", which states:

Consider the effect of the change on structures, systems, and components (SSCs) of the plant to determine how the proposed change affects plant Page 1 of 3

RHR LCO Note RAI operations, any design function or an analysis that verifies the capability of an SSG to perform a design function. Determine if the proposed amendment would change any of the previously evaluated accidents in the updated final safety analysis report (UFSAR). The word "accidents" refers to anticipated (or abnormal) operational transients and postulated design basis accidents ...

The term "anticipated operational occurrences" is defined in 10 CFR Part 50, Appendix A, "General Design Criteria for Nuclear Power Plants", as those conditions of normal operation which are expected to occur one or more times during the life of the nuclear power unit. Further guidance is provided in NUREG-0800, "Standard Review Plan",

Chapter 15.0, which categorizes a single error of an operator as an example of anticipated operational occurrences (AOOs) in pressurized-water reactor (PWR) design.

NSPM recognizes that there have been operating experiences within the nuclear industry where inappropriate valve manipulations have caused system actuations, drain down events, and system or component inoperability. Based on the discussion above, inappropriate valve manipulation resulting in an impact to RHR system or ECCS operability could be considered an initiator of an AOO. Therefore, by this letter, NSPM is revising the response to question 1 of the Significant Hazards Consideration provided in the February 20, 2013 (ML13053A199), submittal. The original response to question 1 in Section 4.3, "Significant Hazards Consideration", of the February 20, 2013, Enclosure stated in part:

The ECCS and RHR subsystem are not accident initiators and therefore the proposed removal of the LCO Note does not involve an increase in the probability of an accident.

This portion of the response is revised as follows to address the NRC RAI and AOO discussion provided above:

The proposed changes do not affect the ECCS and RHR subsystem design, the interfaces between the RHR subsystem and other plant systems' operating functions, or the reliability of the RHR subsystem. The proposed changes do not change or impact the initiators and assumptions of the analyzed accidents.

Therefore, the ECCS and RHR subsystems will be capable of performing their accident mitigation functions, and the proposed removal of the LCO Note does not involve an increase in the probability of an accident.

The following response to question 1 of the Significant Hazards Consideration supersedes the entire response to question 1 of the Section 4.3 "Significant Hazards Consideration", previously provided in the Enclosure to the February 20, 2013 (ML13053A199), submittal:

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

Response: No.

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RHR LCO Note RAI This license amendment request proposes to revise the Technical Specification for ECCS operability requirements in Mode 4 by removing the LCO Note which allows the RHR subsystem to be considered operable for ECCS when aligned for shutdown cooling. These changes will require one train of RHR to be aligned for ECCS operation throughout the mode and other specified conditions of applicability.

The proposed changes do not affect the ECCS and RHR subsystem design, the interfaces between the RHR subsystem and other plant systems' operating functions, or the reliability of the RHR subsystem. The proposed changes do not change or impact the initiators and assumptions of the analyzed accidents.

Therefore, the ECCS and RHR subsystems will be capable of performing their accident mitigation functions, and the proposed removal of the LCO Note does not involve an increase in the probability of an accident.

The proposed removal of the LCO Note will require that one train of RHR is aligned for ECCS operation during the mode and other specified conditions of applicability which assures that one train of ECCS is operable to mitigate the consequences of a loss of coolant accident. Thus the proposed removal of the LCO Note does not involve a significant increase in the consequences of an accident.

Therefore, the proposed Technical Specification changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

Although the response to 10 CFR 50.92(c) question (1) is revised, the conclusion has not changed: Northern States Power Company, a Minnesota corporation (NSPM) 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.

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