ML050610615

Issuance of License Amendment 258 Removal of Shutdown Cooling Automatic Closure Interlock

ML050610615
Person / Time
Site:	Arkansas Nuclear
Issue date:	03/30/2005
From:	Holland D NRC/NRR/DLPM/LPD4
To:	Forbes J Entergy Operations
Holland D, NRR/DLPM, 415-1436
References
TAC MC3799
Download: ML050610615 (13)

Text

March 30, 2005 Mr. Jeffrey S. Forbes Site Vice President Arkansas Nuclear One Entergy Operations, Inc.

1448 S. R. 333 Russellville, AR 72801

SUBJECT:

ARKANSAS NUCLEAR ONE, UNIT NO. 2 (ANO-2) - ISSUANCE OF AMENDMENT RE: REMOVAL OF SHUTDOWN COOLING AUTOMATIC CLOSURE INTERLOCK (ACI) (TAC NO. MC3799)

Dear Mr. Forbes:

The Commission has issued the enclosed Amendment No. 258 to Facility Operating License No. NFP-6 for ANO-2. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated July 8, 2004, as supplemented by letters dated February 2, March 8, and March 28, 2005.

The amendment removes the ACI function from the TSs and deletes the surveillance requirement associated with the ACI. Significant emphasis has been placed on increasing the shutdown cooling system (SDC) reliability in pressurized water reactors (PWRs). As a result, several PWRs have had the ACI function removed from the SDC because historical data indicate that ACI is a significant contributor to the loss of SDC events. The amendment also allows for a higher setpoint of the open permissive interlock (OPI) through a license condition.

A copy of our related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice.

Sincerely,

/RA/

Drew G. Holland, Project Manager, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-368

Enclosures:

1. Amendment No. 258 to NFP-6

2. Safety Evaluation cc w/encls: See next page

Mr. Jeffrey S. Forbes March 30, 2005 Site Vice President Arkansas Nuclear One Entergy Operations, Inc.

1448 S. R. 333 Russellville, AR 72801

SUBJECT:

ARKANSAS NUCLEAR ONE, UNIT NO. 2 (ANO-2) - ISSUANCE OF AMENDMENT RE: REMOVAL OF SHUTDOWN COOLING AUTOMATIC CLOSURE INTERLOCK (ACI) (TAC NO. MC3799)

Dear Mr. Forbes:

The Commission has issued the enclosed Amendment No. 258 to Facility Operating License No. NFP-6 for ANO-2. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated July 8, 2004, as supplemented by letters dated February 2, March 8, and March 28, 2005.

The amendment removes the ACI function from the TSs and deletes the surveillance requirement associated with the ACI. Significant emphasis has been placed on increasing the shutdown cooling system (SDC) reliability in pressurized water reactors (PWRs). As a result, several PWRs have had the ACI function removed from the SDC because historical data indicate that ACI is a significant contributor to the loss of SDC events. The amendment also allows for a higher setpoint of the open permissive interlock (OPI) through a license condition.

A copy of our related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice.

Sincerely,

/RA/

Drew G. Holland, Project Manager, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-368

Enclosures:

1. Amendment No. 258 to NFP-6

2. Safety Evaluation cc w/encls: See next page DISTRIBUTION:

PUBLIC PDIV-1 Reading RidsNrrDlpmLpdiv (HBerkow)

RidsNrrPMDHolland RidsOgcRp THsii RidsAcrsAcnwMailCenter GHill (2) RidsNrrDlpmLpdiv1 (AHowe)

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PHearn RidsNrrDlpmDpr HGarg Accession No.ML050610615 OFFICE PDIV-1/PM PDIV-1/LA SRXB EEIB IROB/BC OGC PDIV-1/SC NAME DHolland DBaxley SSun EMarinos TBoyce AHodgdon AHowe DATE 3/29/05 3/29/05 3/7/05 3/9/05 3/10/05 3/29/05 3/30/05 OFFICIAL RECORD COPY

ENTERGY OPERATIONS INC.

DOCKET NO. 50-368 ARKANSAS NUCLEAR ONE, UNIT NO. 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No.258 License No. NFP-6

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Entergy Operations, Inc. (the licensee) dated July 8, 2004, as supplemented by letters dated February 2, March 8, and March 28, 2005, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this license amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.c.(2) of Facility Operating License No. NFP-6 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 258, are hereby incorporated in the renewed license.

The licensee shall operate the facility in accordance with the Technical Specifications.

3. The license amendment is effective as of its date of issuance and shall be implemented within 30 days of issuance and is subject to the following license condition proposed in the licensee's letter dated March 28, 2005:

Entergy shall maintain the Open Permissive Interlock (OPI) function of the associated Shutdown Cooling System motor-operated valves. The OPI function shall serve to prevent inadvertant valve operation when Reactor Coolant System pressure is above 400 psia.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Allen G. Howe, Chief, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: March 30, 2005

ATTACHMENT TO LICENSE AMENDMENT NO. 258 RENEWED FACILITY OPERATING LICENSE NO. NFP-6 DOCKET NO. 50-368 Replace the following page of the Appendix A Technical Specifications with the attached revised page. The revised page is identified by amendment number and contains marginal lines indicating the areas of change.

Remove Insert 3/4 5-4 3/4 5-4

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 258 TO FACILITY OPERATING LICENSE NPF-6 ENTERGY OPERATIONS, INC.

ARKANSAS NUCLEAR ONE, UNIT NO. 2 DOCKET NO. 50-368

1.0 INTRODUCTION

By application dated July 8, 2004 (ML041960465), as supplemented by letters dated February 2, (ML050390334), March 8, and March 28, 2005, Entergy Operations, Inc.

(the licensee) requested changes to the Technical Specifications (TSs) for Arkansas Nuclear One, Unit 2 (ANO-2). The supplements dated February 2, March 8, and March 28, 2005, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the staff's original proposed no significant hazards consideration determination as published in the Federal Register on August 31, 2004 (69 FR 53106)

The proposed changes would remove the shutdown cooling (SDC) Automatic Closure Interlock (ACI) function from the TSs and delete the surveillance requirement associated with the ACI from ANO-2 TSs Surveillance Requirement (SR) 4.5.2.d.1. In addition, the licensee has proposed a license condition requiring that the Open Permissive Interlock (OPI) feature be maintained operable with the set point increased from 300 pounds per square inch absolute (psia) to 400 psia.

The SDC system is designed as a low pressure system. The SDC suction line inside containment contains two normally de-energized locked-closed motor operated isolation valves (MOVs) in series, which isolate the SDC low pressure piping from the normal reactor coolant system (RCS) pressure. Administrative controls, procedures, and interlocks prevent opening these valves before the RCS has been depressurized. Key-operated control switches are provided in the control room to permit opening of the isolation valves. Interlocks prevent the valves from being opened unless the RCS pressure is below 300 psia (OPI set point).

Although the reactor coolant pressure boundary ends at the second isolation valve inside containment, there is a third in-series MOV located just outside of containment. The third valve is normally de-energized and locked closed. The low pressure piping between the second inside isolation MOV and third MOV is protected from over-pressure by a relief valve.

Operating procedures, administrative controls, and the OPI provide assurance that the isolation valves are not open when the pressure in the RCS is greater than the design pressure of the SDC suction piping.

2.0 REGULATORY EVALUATION

Section 182a of the Atomic Energy Act (the Act) requires applicants for nuclear power plant operating licenses to include TSs as part of the license. These TSs are derived from the plant safety analyses.

The staff reviewed the proposed changes for compliance with 50.36 of Title 10 of the Code of Federal Regulations (10 CFR) and agreement with the precedent as established in NUREG-1432, Standard Technical Specifications [STS] Combustion Engineering Plants. In general, licensees cannot justify TS changes solely on the basis of adopting the model STS.

To ensure this, the staff must make a determination that proposed changes maintain adequate safety. Changes that result in relaxation (less restrictive condition) of current TS requirements require detailed justification.

In general, there are two classes of changes to TSs: (1) changes needed to reflect contents of the design basis (or are derived from the design basis), and (2) voluntary changes to take advantage of the evolution in policy and guidance as to the required content and preferred format of TSs over time. This amendment deals with the second class of change; namely, the licensee proposes to delete the surveillance requirement associated with the SDC ACI, ANO-2 TS SR 4.5.2.d.1.

Licensees may request revisions to the TSs to adopt improved STS format and content provided that plant-specific review supports a finding of continued adequate safety because:

(1) the change is editorial, administrative, or provides clarification (i.e., no requirements are materially altered), (2) the change is more restrictive than the licensees current requirement, or (3) the change is less restrictive than the licensees current requirement, but nonetheless still affords adequate assurance of safety when judged against current regulatory standards. The detailed application of this general framework, and additional specialized guidance, are discussed in section 3.0 below.

3.0 TECHNICAL EVALUATION

The SDC design pressure is 575 psig. The SDC suction line inside containment contains two normally de-energized locked-closed MOVs in series, ensuring that the low pressure piping is not exposed to normal operating RCS pressure or higher. Administrative controls, procedures, and interlocks prevent opening these valves before the RCS has been depressurized.

Currently the interlocks prevent the valves from being opened unless the RCS pressure is

below 300 psia (OPI set point). If a valve has been opened and the RCS pressure rises above the set point, the valve is automatically closed by the ACI. The proposed change deletes the surveillance requirement associated with the SDC ACI. Two low temperature over-pressure (LTOP) relief valves located outside containment have set points less than or equal to 430 pounds per square inch-gage pressure (psig). In the event of a loss of the ACI, the LTOP relief valves would protect the SDC system until the RCS could be isolated by the MOVs.

The industry has experienced a number of spurious valve closures that resulted in a loss of SDC system capability caused at least in part by the presence of ACI. Although the removal of the ACI may increase the potential for over-pressurizing the low pressure SDC system, the capability to isolate the system with the MOVs and the LTOP relief valves protecting the SDC system significantly reduces the potential for over-pressurizing the SDC system.

Removal of the ACI is expected to reduce the incidence of events resulting in or contributing to the loss of SDC system capability to cool the reactor core during shutdown or refueling operations due to inadvertent closure of a suction MOV.

Increasing the OPI set point from 300 psia to 400 psia provides a larger operating band during the transition to and from SDC operations for plant cooldown and heatup, while maintaining significant operating margin to both the LTOP relief valve set points and the SDC design pressure rating.

The ANO-2 SDC system and associated equipment, in conjunction with station procedures and strict administrative controls, provide sufficient assurance that the SDC system will not be inadvertently subjected to pressures above the system design pressure. The ACI function is, therefore, not required to provide this protection to the SDC system piping.

NRC Technical Position (BTP) 5-1 describes the ACI function. In order to increase the reliability of the SDC system as a method of removing core decay heat from the RCS and decrease the probability of future loss of SDC events, the licensee proposes to delete the ACI requirements from the ANO-2 TSs and physically remove this function.

Provided below is a review of the criteria set forth in 10 CFR 50.36 for TS limiting conditions for operation that must remain is TS and their applicability to the removal of the ACI function from TS:

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

Two diverse restricted-range pressure measurement channels provide a control room indication of RCS pressure during plant startup and shutdown in the control room. The operability of the ACI function will not affect these indications. The ACI function is not part of installed instrumentation used to detect abnormal degradation of the RCS pressure boundary.

Criterion 2- A process variable, design feature, or operating restriction that is an initial condition of a design basis accident (DBA) or transient analysis that either assumes the failure of or presents a challenge to the integrity of the fission product barrier.

A review of the Safety Analysis Report (SAR) Chapter 15 accident analysis for ANO-2 reveals that the ACI function is not credited in the mitigation or prevention of any accidents, is not assumed as an initial condition of a design basis accident or transient analysis, and, therefore, does not meet this criterion for inclusion in the TSs.

Criterion 3- A structure system or component that is part of the primary success path and which functions or actuates to mitigate a DBA or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

A review of the ANO-2 SAR Chapter 15 accident analysis indicates that the ACI function is not credited in the mitigation or prevention of any accidents and, therefore, does not meet this criterion for inclusion in the TSs.

Criterion 4- A structure, system, or component which operating experience or probabilistic risk assessment has shown to be significant to public health and safety.

The ACI function is considered not to be a significant risk-reduction contributor to core damage frequency and offsite dose. Based on an industry study as described in CE NPSD-550, Risk Evaluation of Removal of Shutdown Cooling System Auto-Closure Interlock, removal of the ACI function will result in an overall safety improvement.

The reason for this is that the removal of the ACI function eliminates spurious trips of SDC during shutdown and refueling, which are plant conditions during which core decay heat removal capability by SDC is crucial.

The staff finds that the licensees proposed TS revision is technically justified and complies with 10 CFR 50.36. On this basis, the NRC staff concludes that deleting the ACI from the TS and increasing the OPI set point for ANO-2 is acceptable.

4.0 REGULATORY COMMITMENTS The licensees July 8, 2004, application contains the following regulatory commitments:

The following table identifies those actions committed to by the licensee related to this action.

Any other statements in the related submittals are provided for information purposes and are not considered to be regulatory commitments.

TYPE (Check one) SCHEDULED COMPLETION COMMITMENT DATE (If Required)

ONE- CONTINUING TIME COMPLIANCE ACTION Prior to removal of the ACI function, independent X valve position indication powered separately from the normal control power source shall be established for each inside containment SDC suction MOV.

Following removal of the ACI function, independent X valve position indication of the inside containment SDC suction MOVs shall be verified functional with the associated breaker control power source de-energized.

Following removal of the ACI function, the OPI X function shall be verified to remain functional.

Prior to removal of the ACI function, Operations procedures will be revised to ensure LTOP relief valves are in service prior to placing SDC in service X and, SDC is removed from service prior to removing the LTOPs from service.

Following removal of the ACI function, the alarm circuitry associated with alerting operators of a high X SDC suction pressure event shall be verified functional.

Entergy commits to submit a request by July 1, 2005, to amend the ANO-2 license condition. This will be accomplished by either proposing a TS X July 1, 2005 surveillance for the OPI function or by providing technical justification that the function is not required to be addressed in the TSs.

The NRC staff finds that reasonable controls for the implementation and for subsequent evaluation of proposed changes pertaining to the above regulatory commitments are best provided by the licensees administrative processes, including its commitment management program. The above regulatory commitments do not warrant the creation of a regulatory requirement (item requiring prior NRC approval of subsequent changes).

5.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Arkansas State official was notified of the proposed issuance of the amendment. The State official had no comments.

6.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding published August 31, 2004 (69 FR 53106). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22 (c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

7.0 CONCLUSION

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

Principal Contributor: P. Hearn Y. Hsii D. Holland Date: March 30, 2005

Arkansas Nuclear One cc:

Senior Vice President Vice President, Operations Support

& Chief Operating Officer Entergy Operations, Inc.

Entergy Operations, Inc. P. O. Box 31995 P. O. Box 31995 Jackson, MS 39286-1995 Jackson, MS 39286-1995 Wise, Carter, Child & Caraway Director, Division of Radiation P. O. Box 651 Control and Emergency Management Jackson, MS 39205 Arkansas Department of Health 4815 West Markham Street, Slot 30 Little Rock, AR 72205-3867 Winston & Strawn 1400 L Street, N.W.

Washington, DC 20005-3502 Mr. Mike Schoppman Framatome ANP 3815 Old Forest Road Lynchburg, VA 24501 Senior Resident Inspector U.S. Nuclear Regulatory Commission P. O. Box 310 London, AR 72847 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 County Judge of Pope County Pope County Courthouse Russellville, AR 72801 March 2005