2CAN079903, Application for Amend to License NPF-6,revising SRs Pertaining to ISI Requirements for SG Tube Circumferential Cracking at top-of-tubesheet During 2P99 Planned mid-cycle Outage

Application for Amend to License NPF-6,revising SRs Pertaining to ISI Requirements for SG Tube Circumferential Cracking at top-of-tubesheet During 2P99 Planned mid-cycle Outage

ML20210K349
Person / Time
Site:	Arkansas Nuclear
Issue date:	07/29/1999
From:	Hutchinson C ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20210K354	List: 2CAN079903, Application for Amend to License NPF-6,revising SRs Pertaining to ISI Requirements for SG Tube Circumferential Cracking at top-of-tubesheet During 2P99 Planned mid-cycle Outage ML20210K357
References
2CAN079903, NUDOCS 9908060082
Download: ML20210K349 (9)

Text

9 Ent rgy operations,Inc.

-Entergy =u Tel $01 +58-4888 C. Randy Hutchinson Vre Presdmt Operatons ANO July 29,1999 2CAN079903 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station OPI-17 Washington, DC 20555'

Subject:

Arkansas Nuclear One - Unit 2 Docket No. 50-368 License No. NPF-6 Proposed Technical Specification Change for Special Steam Generator Inspection Gentlemen-Attached for your review and approval is a proposed Technical Specification (TS) change revising the requirements associated with Arkansas Nuclear One, Unit 2 (ANO-2), provisions for steam generator tubing and repair. The proposed change primarily affects the ANO-2 Surveillance Requirements pertaining to inservice inspection requirements for steam generator tube circumferential cracking at the top-of-tubesheet (TTS) during the 2P99 planned mid-cycle outage.

On June 2,1999, Entergy Op'erations submitted the operational assessment for steam generator (SG) tubing for the 14 operational cycle at ANO-2 (2CAN069901) to the NRC.

The operational assessment was also discussed vith the Staff during a meeting held June 28,1999. The ' operational assessment concluded that a mid-cycle limited scope inspection of the hot leg tubes for axial cracks would be appropriate, while a full operating cycle between inspections for TTS circumferential cu.cking was acceptable. However for conservatism, Entergy Operations indicated our intent during the June meeting to also perform a limited scope TTS inspection during the planned 2P99 mid-cycle outage to minimize the potential for primary-to-secondary leakage through the SG tubing. The.

proposed scope and expansion criteria for this limited scope inspection does not correspond i with the current ANO-2 TSs, therefore requiring a one time change. Additionally, current TSs prohibit SG tubing inservice inspections at a frequency ofless 12 months. The 2P99 SO ,f inspection will be performed approximately nine months after the previous inspection. A j similar aingle inspection change was previously approved by the Staff on January 5,1995, in ANO-2 TS Amendment 158 for the 2P95-1 steam generator inspection which occurred in

\[0 January 1995.

The proposed change has been evaluated in accordance with 10CFR50.91(a)(1) using criteria in 10CFR50.92(c) and it has been determined that this change involves no significant hazards considerations. The bases for these determinations are included in the attached submittal.

9908060082 990729 PDR ADOCK.05000368 P- PDR ._

U. S. NRC July 29,1999 2CAN079903 Page 2 4

Although this request is neither exigent nor emergency, prompt review and approval of this proposed amendment is requested prior to the beginning of the mid-cycle outage which is currently scheduled to begin on November 5,1999. We request that the license amendment be eff'ective upon issuance.

Very truly y s ,/) [/// _

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.) C Jjd g attachment To the best of my knowledge and belief, the statements contained in this submittal are true.

SUBSCRIBED AND SWORN TO before me, a Nota Public in and for b County and the State of Arkansas, this M" day of Oil >_ , 1999. '

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, U. S. NRC '

July 29,1999 2CAN079903 Page 3 l .

cc: Mr. Ellis W. Merschoff Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 l NRC Senior Resident Inspector Arkansas Nuclear One P.O. Box 310 I

London, AR 72847 l

l Mr. Chris Nolan NRR Project Manager Region IV/ANO-2 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-D-18 One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. David D. Snellings Director, Division ofRadiation Control and Emergency Management Arkansas Department ofHealth 4815 West Markham Street Little Rock, AR 72205 l

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ATTACHMENT IQ ,

I 2CAN079903 PROPOSED TECHNICAL SPECIFICATION AND l

RESPECTIVE SAFETY AN_ALYSES IN_THE MATTER OF AMENDING LICENSENO NPEdli l

ENTERGY OPERATIONS. INC. I ARKANSAS NUCLEAR ONE. UNIT TWO DOCKET NO. 50-368 l

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Attachment to 2CAN079903 I

Page 1 sf 5 DESCRIPTION OF PROPOSED CHANGES The proposed changes to the Arkansas Nuclear One, Unit 2 (ANO-2), Technical

, Specifications (TSs) allow the performance of a special steam generator (SG) tubing inspection during the 2P99 mid-cycle outage at a shorter frequency and utilizing different '

scope and expansion criteria than currently specified. A note is to be added to TS 4.4.5.0 specifying the following:

• The surveillance requirements of Specification 3.4.5 do not apply to the special steam generator tube inspection to be performed during the 2P99 outage scheduled to begin in November 1999, e The scope and expansion criteria for the inspection are specified in correspondence to the NRC submitted under separate cover, e The s; ope and expansion criteria shall be approved by the NRC prior to entering Mode 4, and e The results of the special inspection shall be reviewed by the Plant Safety Committee prior to entering Mode 4 and reported to the NRC within 30 days of entering Mode 4. ,

BACKGROUND l

Since the development and addition of the essentially generic augmented SG inservice inspection requirements in the TSs based upon Rwgulatory Guide 1.83, new degradation mechanisms and specific areas of concern in the SGs have become more prominent which l require inspection programs that supplement current TS requirements. Areas for which special SG tube inspections may vary from the standardized TS inspections are described below:

1. Inspection Frequency Surveillance Requirement 4.4.5.3.a requires inservice inspections to be performed at intervals not less than 12 months after the previous inspection. The next ANO-2 mid-cycle outage for a special steam generator inspection is scheduled to start November 5,1999. This is approximately nine months after the last inservice j inspection conducted during refueling outage 2R13 and, therefore, is considered a special inspection since it cannot be credited as an insenice inspection.

2. Inspection Scope Surveillance Requirement 4.4.5.2.b.3 requires the first sample of tubes selected for each inservice inspection to be inspected from the point of entry (hot leg side) completely around the U-bend to the top support of the cold leg. This requirement is j i

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A**ehmaat to 2CAN079903 Page 2 cf 5 not appropriate for special inspections such as the ANO-2 inspection to be conducted during the next planned mid-cycle outage (2P99), since the specific areas ofinterest have already been determined based on previous inspection history to include only the straight portion of the tubes in the hot leg for a general bobbin coil inspection and a smaller portion of the tube length (the top of the hot leg tubesheet, TTS) for a specific inspection for circumferential cracking.

3. Expansion Criteria i l

Table 4.4-2 of the TSs includes required expansions of the SG inspection based upon the results of the previous sample inspected. For example, if the first sample inspected resulted in one tube being plugged or repaired, an additional 6% of the tubes in that generator, assuming a one steam generator inspection, would need to be inspected. If more than 1% of the tubes needed to be plugged or repaired, all the tubes in the SG '

i would need to be inspected as well as 12% in the second SG. If the same expansion criteria were applied to the 2P99 TTS inspection, many tubes in areas where circumferential cracking has nev:r been seen would be required to be inspected.

On June 2,1999, Entergy Operations submitted the operational assessment for SG tubing for i I

the 14* operational cycle at ANC 2 (2CAN069901) to the NRC. The operational assessment was also discussed with the Staff during a meeting held June 28,1999. The operational assessment concluded that a mid-cycle limited scope inspection of the hot leg tubes for axial cracks would be appropriate, while a full operating cycle between inspections for TTS circumferential cracking was acceptable. However for conservatism, Entergy Operations indicated our intent during the June meeting to also perform a limited scope TTS inspection during the planned 2P99 mid-cycle outage to minimize the potential for primary-to-secondary leakage through the SG tubing. The proposed scope and expansion criteria for this limited scope inspection does not correspond with the current ANO-2 TSs, therefore requiring a one time change. Additionally, current TS: prohibit SG tubing inservice inspections at a frequency ofless 12 months. The 2P99 SG inspection will be performed approximately nine months after the previous inspection. A similar single inspection change was previously approved by the Staff on January 5,1995, in ANO-2 TS Amendment 158 for the 2P95-1 steam generator )

inspection which occurred in January 1995.  !

DISCUSSION OF CHANGE The proposed change to TS 4.4.5.0 will resolve the problems described above with compliance to the TSs during tie special inspection to be conducted during 2P99 by specifying that the Surveillance Requirements of TS 3.4.5 do not apply to the 2P99 special steam generator inspection. Several general requirements are added for the specific inspection to be conducted during 2P99. First, the appropriate scope and expansion criteria for the special inspection will be developed by Entergy Operations and approved by the Staff. A new requirement has also been added for the Plant Safety Committee (PSC) to review the results of the 2P99 special inspection prior to entering Mode 4, at whicl time the steam generators

Attachment to 2CAN079903 Page 3 of 5 are declared operable. Typically, the PSC review would assure the adequacy of the inspection considering previously identified damage mechanisms and any newly identified phenomena A requirement to provide a special report to the NRC within 30 days of entering Mode 4 discussing the 2P99 inspection results has also been added to the TSs.

The proposed change has been determined to be acceptable since the one-time inspection will be performed after a shorter interval between inspections, approximately nine months, than required by the TSs. The special one-time inspection will not affect the current TS interval between normal inservice inspections; it is an additional inspection, not a replacement. The proposed change requires the Staff to review and approve the scope and expansion criteria for the one-time special inspection to provide additional oversight of their adequacy. All defective tubes found during this special inspection will be appropriately repaired.

DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION Entergy Operations, Inc. is proposing that the Arkansas Nuclear One Unit 2 (ANO-2)

Operating License be amended to exempt the special steam generator (SG) tubing inspection to be conducted during the 2P99 mid-cycle outage from the current Technical Specification (TS) requirements for augmented SG tubing inspections. The special inspection will be in addition to, not in lieu of, the SG tubing inspections currently required by the TSs. The NRC will approve the scope and expansion criteria for the special inspection.

An evaluation of the proposed change has been performed in accordance with 10CFR50.91(a)(1) regarding no significant hazards considerations using the standards in 10CFR50.92(c). A discussion of these sisndards as they relate to this amendment request i

follows:  ;

Criterion 1 - Does Not Involve a Significant Increase in the Probability or Consequences of an Accident Previously Evaluated.

This change has no actual impact on any previously analyzed accident in the final  ;

safety analysis report (FSAR). A double-ended break of one steam generator tube is i postulated as part of the ANO-2 design basis accident evaluation. The change peridts Entergy Operations to determine the appropriate scope and expansion criteria for a special steam generator tube inspection that is being performed at a frequency more conservative than that of the augmented inservice inspection program included in the TSs. The special inspection will find and repair certain steam generator tubing flaws that would otherwise remain in service until the next scheduled refueling outage. The increased inspection frequency reduces the probability that a flaw in a steam generator l tube could grow to a size that would affect the leakage or structural integrity of the tube. The augmented inservice inspection program contained in the TSa is not being modi 6ed.

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Attachment to 2CAN079903 Page 4 cf 5 This change does not modify any parameter that will increase radioactivity in the primary system or increase the amount of radioactive steam released from the secondary safety valves or atmospheric dump valves in the event of a tube rupture.

Therefore, this change does Dol involve a significant increase in the probability or consequences of any accident previously evaluated.

l Criterion 2 - Does Not Create the Possibility of a New or Different Kind of Accident from any Previously Evaluated.

The scope of this change does not establish a potential new accident precursor. The design basis accident analyses for ANO-2 include the consequences of a double-ended break cf one steam generator tube which bounds other postulated failure mechanisms.

The proposed change would permit determination of alternate inspection criteria for a  ;

special inspection which is in addition to the periodic inservice inspections required by j the TSs. The equipment used in the special inspection would not affect any plant  !

components differently than those used for current TS required inspections. I Therefhre, this chrage does not create the possibility of a new or different kind of accident from any previously evaluated. ,

I Criterion 3 - Does Not Involve a Significant Reduction in the Margin of Safety.

As previously stated, a double-ended rupture of one steam generator tube is accounted for in the ANO-2 design basis accident analysis. Considering that the 2P99 special inspection is in addition to the inservice inspection program defined in the ANO-2 TSs and that leakage detection capability is not being modified, performance of a special inspection of any scope will increase the margin of safety over the current TS requirements.

Therefore, this change does not involve a significant reduction in the margin of safety.

Therefore, based upon the reasoning presented above and the previous discussion of the amendment regeest, Entergy Operations has determined that the requested change does nel involve a significant hazards consideration.

1 ENVIRONMENTALIMPACT EVALUATION 10 CFR 51.22(c) provides criteria for and identification of licensing and regulatory actions eligible for categorical exclusion from performing an environmental assessment. A proposed I

amendment to an operating license for a facility requires no environmental assessment 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

At*-hmaat to 2CAN079903 Page 5 of 5 increase in the amounts of any effluents that may be released off-site, or (3) result in a significant increase in individual or cumulative occupational radiation exposure. Entergy Operations, Inc. has reviewed this license amendment and has determined that it meets the eligibility criteria for categorical exclusion set forth in 10 CFR St.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 proposed license amendment. The basis for this determinationis as follows:

1. The proposed license amendment does not involve a significant hazards consideration as described previously in the evaluation.

2. As discussed in the significant hazards evaluation, this change does not result in a significant change or significant increase in the radiological doses for any Design Basis Accident. The proposed lice ise amendment does not result in a significant change in the types or a significant increase in the amounts of any effluents that msy be released off-site.

3. The proposed license amendment does not result in a significant increase to the individual or cumulative occupational radiation exposure because most steam generator inspection activities are performed using robotics to limit occupational doses while ALARA practices are maintained for the remaining SG inspection activities.

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