ML033450397

Duke Power Co. Amendment Request for McGuire Technical Specifications 3.4.11

ML033450397
Person / Time
Site:	Mcguire, McGuire
Issue date:	12/04/2003
From:	Gordon Peterson Duke Power Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML033450397 (20)

Text

J^fuke GARY R. PETERSON rrWVPowere A Duke Energy Company Vice President McGuire Nuclear Station A Duke Energy Company Duke Power MGOI VP / 12700 Hagers Ferry Road Huntersville, NC 28078-9340 704 875 5333 704 875 4809 fax grpeters@duke-energy.com December 4, 2003 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk

SUBJECT:

Duke Energy Corporation McGuire Nuclear Station Units 1 and 2 Docket Nos. 50-369, 50-370 License Amendment Request for:

McGuire Technical Specifications 3.4.11, Pressurizer Power Operated Relief Valves, Surveillance Requirement 3.4.11.1 Pursuant to 10CFR50.90, Duke Energy Corporation (Duke) is submitting a license amendment request (LAR) for the McGuire Nuclear Station Facility Operating Licenses and Technical Specifications (TS). This LAR is applicable to TS 3.4.11, Pressurizer Power Operated Relief Valves (PORV), and the TS change proposed in this LAR extends the Frequency for Surveillance Requirement (SR) 3.4.11.1. This SR requires the closing of each Reactor Coolant System (NC) PORV Block Valve from its normally open position at the current test frequency of 92 days. This test is commonly referred to as the quarterly NC PORV Block Valve stroke time test, and within this LAR, Duke is proposing to extend this test Frequency to 18 months, consistent with the schedule for refueling outages. Conforming changes are also being made to the associated Bases and these are included for information.

As detailed in Attachment 3, the change being proposed to McGuire SR 3.4.11.1 is based upon the maintenance and testing histories for the NC PORV Block Valves and the provisions of NUREG-1482. These histories demonstrate that a reduction in surveillance testing Frequency will result in no decrease in the performance level of these valves, while contributing to an improvement in these valves reliability and maintenance requirements.

1 D www. duke-energy. corn

U. S. Nuclear Regulatory Commission December 4, 2003 Page 2 The contents of this amendment package are as follows:

• Attachment 1 provides a marked copy of the existing TS for McGuire Units 1 and 2. The marked copies show the proposed changes.

• Attachment 2 provides the reprinted Technical Specifications pages for McGuire Units 1 and 2.

• Attachment 3 provides a Description of the Proposed Changes and Technical Justification.

• Pursuant to 10 CFR 50.92, Attachment 4 documents Duke's determination that this LAR contains No Significant Hazards Consideration.

• Pursuant to 10 CFR 51.22(c)(9), Attachment 5 provides the basis for the categorical exclusion from performing an Environmental Assessment/Impact Statement.

Implementation of this LAR in the Facility Operating Licenses and Technical Specifications will not impact the McGuire Updated Final Safety Analysis Report (UFSAR). However, conforming changes to the McGuire Inservice Testing Program Manual will be necessary.

In accordance with Duke administrative procedures and the Quality Assurance Program Topical Report, the changes contained in this LAR have been reviewed and approved by the McGuire Plant Operations Review Committee. This LAR has also been reviewed and approved by the Duke Nuclear Safety Review Board.

Pursuant to 10 CFR 50.91, a copy of this LAR is being sent to the designated official of the State of North Carolina.

Implementation of the changes proposed in this LAR at McGuire will provide additional operational flexibility and reliability without a significant increase in risk. Duke is requesting NRC review and approval of this LAR by December 4, 2004. It has been determined that the NRC's standard 30-day implementation grace period will be adequate for this LAR.

U. S. Nuclear Reguiatory Commission December 4, 2003 Page 3 This submittal document contains these commitments:

1. Duke will implement this LAR within 30 days following NRC approval.

2. Duke will make the necessary revisions to the McGuire Inservice Testing Program Manual in accordance with the applicable codes and regulations.1 ' 2 Inquiries on this matter should be directed to J. S. Warren at (704) 382-4986.

Ver truly yrs, G. R. Peterson xc w/Attachments:

L. A. Reyes, Regional Administrator U. S. Nuclear Regulatory Commission, Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, GA 30303 R. E. Martin (Addressee Only)

NRC Senior Project Manager (MNS)

U. S. Nuclear Regulatory Commission Mail Stop 0-8 H12 Washington, DC 20555-0001 J. B. Brady Senior Resident Inspector U. S. Nuclear Regulatory Commission McGuire Nuclear Site Beverly 0. Hall, Section Chief Radiation Protection Section 1645 Mail Service Center Raleigh, NC 27699-1645 1 10 CFR 50.55a(a)(3)(ii), Codes and standards.

2 ASME Boiler and Pressure Vessel Code,Section XI, Subsection IWV.

U. S. Nuclear Regulatory Commission December 4, 2003 Page 4 G. R. Peterson, affirms that he is the person who subscribed his name to the foregoing statement, and that all the matters and facts set forth herein are true and correct to the best of his knowledge.

G. R. Peterson, Site Vice President N _

s;~ - -A,

--R Subscribed and sworn to me: Becher Date O r .r-YAd-- _ z

, -- , &vC,0 , Notary Public

,~~~~~~~~~~~~~~~~~~

My commission expires: , UaS / '71 -O6 Date SEAL

Attachment 1 McGuire Units 1 and 2 Technical Specifications Marked Copy

Pressurizer PORVs 3.4.11 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.11.1 -- D-NOTE--

Not required to be met with block valve closed in (

accordance with the Required Action of Condition A, B, or E.

Perform a complete cycle of each block valve. da SR 3.4.11.2 NOTE Required to be performed in MODE 3 or MODE 4 when the temperature of all RCS cold legs is > 3000F and the block valve closed.

Perform a complete cycle of each PORV. 18 months SR 3.4.11.3 Verify the nitrogen supply for each PORV is OPERABLE 18 months by:

a. Manually transferring motive power from the air supply to the nitrogen supply,

b. Isolating and venting the air supply, and

c. Operating the PORV through one complete cycle.

McGuire Units 1 and 2 3.4.1 1-4 Amendment Nos.

Pressurizer PORVs

- B 3.4.1 1 BASES  ;.A ACTIONS (continued)

H.1 and H.2 If the Required Actions of Condition F or G are not met, then the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODES 4 and 5, maintaining PORV OPERABILITY may be required. See LCO 3.4.12.

SURVEILLANCE CO '2 11I REQUIREMENTS, Bock valve clng verifes that the valvecan e closed i needed The basis r the Frequency of 92 days the ASME Code, Secti~ Xi (Ref. 4/ the block valve is closed t olate a PORV that is c ale of bein anually cycled, the OPERA LITY of the block valveiso im dance, because opening the lock valve is necessary to ermit the P RV to be used for manual c trol of reactor pressure. If e block valve is closed to isolate an o erwise inoperable PORV, e maximum Completion Time to restore e PORV and open the blol valve is 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, which is well Wi in the allowable limits (25%/to extend the

'block valve Frequency o 92 days. Furthermore, the test requirements would be completed by he reopening of a recently osed block valve upon restoration of th P.ORV to OPERABLE stats (i.e., completion of the Required Action fulfills the SR).

The Note modifies this SR by stating that it is not required to be met with the block valve closed, in accordance with the Required Action of this LCO.

SR 3.4.11.2 SR 3.4.11.2 requires a complete cycle of each PORV. Operating a PORV through one complete cycle ensures that the PORV can be manually actuated for mitigation of an SGTR. The Frequency of 18 months is based on a typical refueling cycle and industry accepted practice.

The SR is modified by a Note which states that the SR is required to be performed in MODE 3 or 4 when the temperature of the RCS cold legs is

> 3001F consistent with Generic Letter 90-06 (Ref. 5).

McGuire Units 1 and 2 B 3.4.1 1-6 Revision No/

INSERT Block valve cycling verifies that the valve(s) can be closed if needed. This testing is performed in order to comply with the ASME Code,Section XI (Ref. 4). The basis for the Frequency of 18 months or refueling outages is the deferral provisions of NUREG-1482 (Ref. 6). Performing stroke time testing during refueling outages is an accepted frequency for inservice testing to demonstrate operability for valves that create a hardship to test during Unit operation. Testing during unit operation under hardship conditions could result in a plant shutdown, which would cause unnecessary challenges to safety systems, undue stress on components, additional cycling of equipment, and could reduce the life expectancy of the plant systems and components.

The testing is performed just before unit outages at full NC pressure and temperature.

Pressurizer PORVs

• B 3.4.11 BASES - *, -

SURVEILLANCE REQUIREMENTS (continued)

SR 3.4.11.3 The Surveillance demonstrates that the emergency nitrogen supply can be provided and is performed by transferring power from normal air supply to emergency nitrogen supply and cycling the valves. The Frequency of 18 months is based on a typical refueling cycle and industry accepted practice.

REFERENCES 1. Regulatory Guide 1.32, February 1977.

2. UFSAR, Section 15.4.

3. 10 CFR 50.36, Technical Specifications, (c)(2)(ii).

4. ASME, Boiler and Pressure Vessel Code, Section Xi.

5. Resolution of Generic Issue 70, "Power-Operated Relief Valve and Block Valve Reliability," and Generic Issue 94, Additional Low-Temperature Overpressure Protection for Light-Water Reactors,"

Pursuant to 10 CFR 50.54(f) (Generic Letter 90-06).

Ak~e6- / A)2L"Gw 'elGV- Rne et .- F fser ,

McGuire Units 1 and 2 B 3.4.1 1-7 Revision No./

Attachment 2 McGuire Units 1 and 2 Technical Specifications Reprinted Pages Remove Page Insert Page 3.4.11-4 3.4.11-4 B3.4.11-6 B3.4.11-6 B3.4.11-7 B3.4.11-7

Pressurizer PORVs 3.4.11 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.11.1 ------------------------------ NOTE------------------------------------

Not required to be met with block valve closed in accordance with the Required Action of Condition A, B, or E.

Perform a complete cycle of each block valve. 18 months SR 3.4.11.2 -------------------------- NOTE---------------------------------

Required to be performed in MODE 3 or MODE 4 when the temperature of all RCS cold legs is > 3000 F and the block valve closed.

Perform a complete cycle of each PORV. 18 months SR 3.4.11.3 Verify the nitrogen supply for each PORV is OPERABLE 18 months by:

a. Manually transferring motive power from the air supply to the nitrogen supply,

b. Isolating and venting the air supply, and

c. Operating the PORV through one complete cycle.

McGuire Units 1 and 2 3.4.1 1-4 Amendment Nos.

Pressurizer PORVs B 3.4.11 BASES ACTIONS (continued)

H.1 and H.2 If the Required Actions of Condition F or G are not met, then the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODES 4 and 5, maintaining PORV OPERABILITY may be required. See LCO 3.4.12.

SURVEILLANCE SR 3.4.11.1 REQUIREMENTS Block valve cycling verifies that the valve(s) can be closed if needed.

This testing is performed in order to comply with the ASME Code, Section Xl (Ref. 4). The Frequency of 18 months is consistent with refueling outages and is based upon the deferral provisions of NUREG-1482 (Ref.

6). Performing stroke time testing during refueling outages is an accepted frequency for inservice testing to demonstrate operability for valves that create a hardship to test during Unit operation. Testing during unit operation under hardship conditions could result in a plant shutdown, which would cause unnecessary challenges to safety systems, undue stress on components, additional cycling of equipment, and could reduce the life expectancy of the plant systems and components. The testing is performed just before unit outages at full NC pressure and temperature.

The Note modifies this SR by stating that it is not required to be met with the block valve closed, in accordance with the Required Action of this LCO.

SR 3.4.11.2 SR 3.4.11.2 requires a complete cycle of each PORV. Operating a PORV through one complete cycle ensures that the PORV can be manually actuated for mitigation of an SGTR. The Frequency of 18 months is based on a typical refueling cycle and industry accepted practice.

The SR is modified by a Note which states that the SR is required to be performed in MODE 3 or 4 when the temperature of the RCS cold legs is

> 300OF consistent with Generic Letter 90-06 (Ref. 5).

McGuire Units 1 and 2 B 3.4.1 1-6 Revision No.

Pressurizer PORVs B 3.4.1 1 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.4.11.3 The Surveillance demonstrates that the emergency nitrogen supply can be provided and is performed by transferring power from normal air supply to emergency nitrogen supply and cycling the valves. The Frequency of 18 months is based on a typical refueling cycle and industry accepted practice.

REFERENCES 1. Regulatory Guide 1.32, February 1977.

2. UFSAR, Section 15.4.

3. 10 CFR 50.36, Technical Specifications, (c)(2)(ii).

4. ASME, Boiler and Pressure Vessel Code, Section Xl.

5. Resolution of Generic Issue 70, "Power-Operated Relief Valve and Block Valve Reliability," and Generic Issue 94, "Additional Low-Temperature Overpressure Protection for Light-Water Reactors,"

Pursuant to 10 CFR 50.54(f) (Generic Letter 90-06).

6. NUREG-1482, Guidelines for Inservice Testing at Nuclear Power Plants."l McGuire Units 1 and 2 B 3.4.11-7 Revision No.

Attachment 3 Description of Proposed Changes and Technical Justification DESCRIPTION OF PROPOSED CHANGES This license amendment request (LAR) proposes a change to the test Frequency for McGuire Technical Specifications (TS)

Surveillance Requirement (SR) 3.4.11.1. Duke Energy Corporation (Duke) is proposing that the Frequency for this SR be 18 months, which is consistent with scheduled refueling outages, instead of the present 92 days. The SR will be performed just before unit shutdown for the outage at full temperature and pressure.

Conforming changes are also being made to the associated Bases for this SR and these Bases changes are included for information within this LAR submittal package.

TECHNICAL JUSTIFICATION

Background

SR 3.4.11.1 is the quarterly stroke time test for the Reactor Coolant System Pressurizer Power Operated Relief Valves (NC PORV) Block Valves. The function of these valves is to remain open during normal operation and to close in the event of leak from an NC PORV. Except for movement to the closed position during unit shutdown to allow for NC PORV stroke time testing, these valves are normally only stroked closed for their own stroke time testing. A reduction in the surveillance testing Frequency will result in an overall improvement in these valves performance and reliability, and reduce maintenance requirements as discussed below. Recent improvements in the trending program maintained by McGuire staff have allowed identification of undesirable effects resulting from performance of the quarterly stroke time testing of the NC PORV Block Valves. These valves are double packed valves which makes it very difficult to achieve optimal loading on the lower packing ring set (below the lantern ring). Trending indicates that leakage thru the lower packing set is experienced to varying degrees following valve stem movement to the open and/or close position. The leakage is typically on the order of 0.100 gpm or less, and usually reseals itself within an operating shift (12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />). Occasionally, sustained lower packing leakage is experienced and tends to worsen until the affected valve is isolated or maintenance is performed.

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Attachment 3 Description of Proposed Changes and Technical Justification Discussion All quarterly stroke time test results for NC PORV Block Valves INC-31B, NC-33A, NC-35B, 2NC-31B, 2NC-33A, and 2NC-35B have been acceptable for all tests performed since October 21, 1996 to the present (203 total tests). This history of successfully meeting test acceptance criteria is a strong point in justifying a reduction in the surveillance test Frequency.

Significant maintenance activity has been focused on improving the reliability of the packing used in the block valves, but due to the inherent double-packed design and rigorous duty, it continues to present leakage risks each time these valves are stroked. Reduction in surveillance testing Frequency is therefore not a result of the inability or lack of effort to maintain these valves properly. The NC PORV Block Valves are 3 inch, ANSI Class 1528, Model 74380-1 Borg Warner flexible wedge gate valves with a Rotork 16NA1X-86 actuator. As discussed below, the packing load for the McGuire NC PORV Block valves is limited by the margin on the actuator size and space limitations preventing live loaded packing while maintaining necessary motor operated valve (MOV) clearance.

The actuator sizing is limited by the spring capability of the NAX actuator. The NAX design is a thrust compensator that is applied to high temperature applications in the event the valve is closed during unit operation. The spring compensator allows stem thermal growth without adding to wedging loads. If closing force is applied to the point where the spring compensator becomes solid (i.e., no spring take-up remains), thermal growth of the stem becomes an issue should the valve be required to close for any amount of time. The margin between minimum closing thrust requirements and the point where the spring compensator becomes solid is approximately 35%. Increases in packing load above normal levels erodes the margin available between minimum closing thrust requirements and the point where the spring compensator becomes solid. Therefore, it is important to keep packing loads at manageable levels.

Another sizing limitation for the MOV is the valve structural limit in the opening direction. These valves have been modified

• with a strengthened disc t-head design and material change from that originally supplied. Even with the improved design, the 2

Attachment 3 Description of Proposed Changes and Technical Justification disc t-head is limiting to the point where opening strokes should be accomplished under no differential pressure. These valves are not normally opened under a differential pressure, since the normally open NC PORV inlet drain valves 1NC-269, NC-270, NC-271, 2NC-269, 2NC-270, and 2NC-271 equalize pressure across the NC PORV Block Valves. The drain valves are ensured open prior to opening the NC PORV Block Valves by procedure.

Since opening loads are a concern, it is very desirable to limit the applied closing force which determines the disc unwedging load.

To facilitate MOV thrust diagnostic testing, a portion of the valve stem is required to be avaialbe for attaching a strain measurement device. Accessibility to the valve stem would be prevented by the presence of live loaded packing. The location of the packing gland studs is such that the portion of the valve stem used to attach the strain measuring device would be obstructed by live loading. If live loading were applied to the NC PORV Block Valves, it would need to be removed to allow MOV testing to be accomplished, which would render the diagnostic testing invalid with live loading later replaced.

The operating environment that these valves are subjected to is a saturated steam-hydrogen vapor at 2230 psig. When surveillance testing these valves, additional thermal cycles are induced by their movement to the closed position and back to the open position. A thorough review was cnducted, and it can be demonstrated that periodic valve stroking to meet the TS requirements increases the rate of packing failures. The most recent failure at McGuire can be directly linked to the stroking of the block valve for the TS requirement. Additionally, other occurrences of NC PORV Block Valve packing leakage resulting from stroke testing have been seen in INPO Operating Experience Reports. These leaks are undesirable from a stress and reliability perspective.

NUREG-1482 allows deferral of valve testing to cold shutdown or refueling outages for conditions that could: 1) result in a plant shutdown, 2) cause unnecessary challenges to safety systems, 3) cause undue stress on components, 4) cause additional cycling of equipment, and 5), contribute to a reduction in the life expectancy of the plant systems and components. Deferral of the quarterly NC PORV Block Valve 3

Attachment 3 Description of Proposed Changes and Technical Justification surveillance testing to a 18.months Frequency (refueling outages) is appropriate when applying the provisions of NUREG-1482 to these valves, and it would also be consistent with the current test Frequency of the McGuire NC PORVs themselves.

Since the PORV Block Valves quarterly surveillance testing Frequency is explicitly defined by the TS in SR 3.4.11.1, NRC approval of an LAR is required to reduce this Frequency to every 18 months (refueling outages). Duke is proposing this test Frequency reduction within this LAR.

Conclusion Duke has determined-that deferral of the quarterly NC PORV Block Valves surveillance testing Frequency to every 18 months (consistent with scheduled refueling outages) is appropriate when applying the provisions of NUREG-1482, and would be consistent with the current test Frequency of the NC PORVs themselves. Historical data at McGuire and other industry experience have demonstrated that the block valves performance is not a concern, and since there are obvious benefits from reducing the Frequency of these valves stroke time testing in regard to equipment reliability and maintenance, Duke is requesting that the NRC approve the proposed change to McGuire SR 3.4.11.1 that is contained in this LAR.

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Attachment 4 No Significant Hazards Consideration Determination Duke Energy Corporation (Duke) has made the determination that this license amendment request (LAR) involves No Significant Hazards Consideration by applying the standards established by the NRC's regulations in 10 CFR 50.92. These three standards are discussed below.

1. Would implementation of the changes proposed in this LAR involve a significant increase in the probability or consequences of an accident previously evaluated?

No, changing the stated Frequency for the Reactor Coolant System Pressurizer Power Operated Relief Valves (NC PORV)

Block Valves stroke time testing from 92 days to 18 months will not cause an increase in the probability of an accident which has been previously evaluated. Except for movement to the closed position during unit shutdown to allow for NC PORV stroke time testing, these valves remain open during normal operation and are only stroked closed for their own stroke time testing. These valves also function to close in the event of a leaking NC PORV.

All tests of these valves performed under the current TS requirements since 1996 (203 total tests) have been acceptable, providing substantial historical justification for the proposed change. Consequently, approval of this LAR will not create operating practices that would cause the failure of the block valves to be significantly more probable. In fact, reducing the number of stroke time tests undergone by these valves would contribute to the future reliability of these valves. Further, a leaking NC PORV is bounded by the McGuire transient analysis for a decrease in reactor coolant inventory; therefore, the proposed change would have no significant impact on any accident consequences that have been previously evaluated.

2. Would implementation of the changes proposed in this LAR create the possibility of a new or different kind of accident from any accident previously evaluated?

No, implementation of this amendment would not create the possibility of a new or different kind of accident from any accident previously evaluated. No new accident causal mechanisms will be created as a result of the NRC approval of this LAR. No changes are being made to the plant which will introduce any new accident causal mechanisms. This amendment does not otherwise impact 1

Attachment 4 No Significant Hazards Consideration Determination any plant systems that are accident initiators; therefore, no new accident types are being created.

3. Would implementation of the changes proposed in this LAR involve a significant reduction in a margin of safety?

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 situation. These barriers include the fuel cladding, the reactor coolant system, and the containment system.

These barriers are not significantly affected by the changes proposed in this LAR. The margin of safety is established through the design of the plant structures, systems, and components, the parameters within which the plant is operated, and the establishment of the setpoints for the actuation of equipment relied upon to respond to an event, and thereby protect the fission product barriers. The NC PORV Block Valves are part of the reactor coolant system, however the applicable transient analysis will remain bounding subsequent to McGuire's implementation of this amendment. Thus the performance of the fission product barriers will not be significantly impacted by implementation of this amendment and no safety margins will be impacted.

Conclusion Based upon the preceding discussion, Duke has concluded that this proposed amendment does not involve a significant hazards consideration.

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Attachment 5 Environmental Assessment/Impact Statement The proposed license amendment request has been reviewed against the criteria of OCFR51.22 for environmental considerations.

The proposed amendment does not involve a significant hazards consideration (see Attachment 4), nor increase the types and amounts of effluents that may be released offsite, nor increase individual or cumulative occupational radiation exposures.

Therefore, the proposed amendment meets the criteria given in 10CFR51.22(c)(9) for a categorical exclusion from the requirement for performing an Environmental Assessment/Impact Statement.

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