ML20207E723

Safety Evaluation Authorizing Proposed Alternative Exam Methods Proposed in Alternative Exam 99-0-002 to Perform General Visual Exam of Accessible Areas & Detailed Visual Exam of Areas Determined to Be Suspect

ML20207E723
Person / Time
Site:	Arkansas Nuclear
Issue date:	06/02/1999
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20207E718	List: ML20207E713 ML20207E723
References
NUDOCS 9906070120
Download: ML20207E723 (6)

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• ] NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30806 4001

\ ..... j' SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST FROM SECTION XI REQUIREMENTS ENTERGY OPERATIONS. INC.

ARKANSAS NUCLEAR ONE. UNIT NOS.1 AND 2 DOCKET NOS. 50-313 AND 50-368

1.0 INTRODUCTION

Title 10 of the Code of Federal Reaulations (10 CFR), Section 50.55a, requires that inservice inspection (ISI) of certain American Society of Mechanical Engineers (ASME) Code Class 1,2, and 3 piping be performed in accordance with Section XI of the ASME Boiler and Pressure

- Vessel Code (Code, or the Code) and applicable addenda, except where altamatives have been authorized or relief has been requested by the licensee and granted by the Commission pursuant to paragraphs (a)(3)(l), (a)(3)(ii), or (g)(6)(i) of 10 CFR 50.55a. In proposing

altomatives or requesting relief, the licensee must demonstrate that (1) the proposed altomatives provide an acceptable level of quality and safety, (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety, or (3) conformance is impractical for its facility.

As published in'the Federal Register (61 FR 41303, dated August 8,1996), the NRC announced an amendment to its regulation in 10 CFR Part 50, Section 50.55a (rule). The rule I incorporated, by reference, the 1992 Edition with 1992 Addenda of Subsections IWE and IWL of Section XI of the ASME Code. Subsections IWE and IWL provide the requirements for ISI of Class CC (concrete containment components) and Class MC (metallic containment components) of light-water cooled power plants. The effective date for the amended rule was September 9,1996, and requires licensees tr> incorporate the new requirements into their ISI plans and complete the first containment ir action by September 9,2001. However, a licensee may submit a request for relief frot one or more requirements of the regulation (or the endorsed Code requirements) with proper Jt tification.

I in accordance with 10 CFR 50.55a(g)(6)(ii)(B), all licensees shall implement the inservice examinations specified for the first period of the first inspection interval in Subsection IWE,

" Requirements for Class MC and Metallic Uners of Class CC Concrete Components of I Light-Water Cooled Plants," of the 1992 Edition with the 1992 Addenda in conjunction with the

. requirements of 10 CFR 50.55a(b)(2)(ix) by September 9,2001. Licensees shall also i

. implement the inservice examinations that correspond to the number of years of operation that  ;

are specified in Subsection IWL, " Requirements for Class CC Concrete Components of Light-Water Cooled Plants," of the 1992 Edition with the 1992 Addenda in conjunction with the requirements of 10 CFR 50.55a(b)(2)(ix) by September 9,2001.

Enclosure 9906070120 990602 PDR ADOCK 05000313 P PDF .

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By letter dated April 1,1999, Entergy Operations, Inc. (the licensee), proposed an attemative to

the requirements of IWL for Arkansas Nuclear One, Units 1 and 2. The NRC's finding with respect to authorizing the altematives or denying the proposed relief request is given below.

2.0 - ALTERN6 The licensee proposes attemative examination methods to those specified in ,

- Table IWL-2500-1, Examination Category L-A (ltem Nos. L1.11 and L1.12), IWL-2310, and i IWL-2510.- The attemative is to perform a general visual examination of the accessible areas

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and a detailed visual examination of those areas determined to be suspect. The proposed examination methods will be consistent with the methods described in the 1997 Addenda of

~ Subsection lWL.

The licensee also proposes alternative examination methods to those specified in Table IWL-2500-1, Examination Category L-B litem No. L2.30), IWL-2310, and IWL-2524. The altemative is to perform a detailed visual exam. nation of both the anchorage hardware and the surrounding concrete.- The proposed examination methods will be consistent with the methods described in the 1997 Addenda of Subsection IWL.

l 2.1 Licensee's Basis for Reauestina Relief The licensee states:

In accordance with 10CFR50.55a(a)(3)(i), Arkansas Nuclear One (ANO) is requesting approval to implement altamative examination methods to those specified in Table IWL-2500-1, Examination Category L-A (Item Nos. L1.11 and L1.12), IWL-2310, and IWL-2510. ANO proposes to perform a general visual examination of the accessible areas and a detailed visual examination of those areas determined to be suspect.

In accordance with 10CFR50.55a(a)(3)(1), ANO is also requesting approval to implement alternative examination methods to those specified in Table IWL-2500-1, Examination Category L-B (item No. L2.30), IWL-2310, and IWL-2524. ANO proposes to perform a detailed visual examination of both the anchorage hardware and the surrounding concrete.

The proposed altamative examination methods have been evaluated by ANO,

' and have determined that the implementation of the attemative methods will provide an acceptable level of quality and safety for the following reasons:

1. ~ The visual examination methods (VT-1C & VT-3C) specified in Examination Category L-A and the visual examination methods (VT-1 and VT-10) specified in Examination Category L-B requires that the visual examination and qualification of the examiners meet the applicable requirements of IWA-2210 and IWA-2300.

The requirements specified in these ASME Code,Section XI provisions for the VT-3C and VT-1C examinations were developed for detecting flaws in metal components and for this reason, are more stringent than those that would be required for

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the detection of degradation on a concrete structure. The requirements of IWA 2210 and IWA 2300 were first introduced in Subsection IWL in the 1992 Addenda. Until the issuance of this Addenda to Subsection lWL, Examination Categories L-A & L-B only required visual examination performed by or under direction of the Responsible Engineer, who is a Registered Professional Engineer. As stated in the NRC's response to Public Comment 2.3 in Attachment 6, Part lli to SECY-96-080, issuance of Final Amendment to 10CFR50.55a to incorporate by Reference the ASME Boller and Pressure Vessel Code,Section XI, DMslon 1,

' Subsection IWE and Subsection IWL, ' Comments received from ASME members on the containment committee indicate that the newer more stringent requirements of IWA-2210 were not intended to be used for the examination of containments and were

- inadvertently included in Subsection lWL." in the 1997 Addenda, the reouirements of IWA-2210 and IWA-2300 were removed, in

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evaluating the requirements of these ASME Code,Section XI '

provisions, ANO concluded that these requirements are not warranted for the examination of concrete surfaces nor the anchorage hardware and its surrounding concrete surfaces and would not provide a compensating increase in quality and safety. 4 2.' Degradation mechanisms for a concrete structure are differant from the degradation mechanisms of Class 1,2, and 3  !

components to which the applicable requirements of IWA 2210 and IWA-2300 were developed. Concrete deterioration and distress, as defined in ACI 201.1, Guide for Making a Condition Survey of Concrete in Service, can be effectively identified by the

_ performance of a general visual examination. As such, ANO has established controls for the performance of a general visual examination of the concrete structure. The generalvisual examination performed by ANO will be a thorough examination of the accessible areas as will the detailed visual examination of the

_ tendon anchorage hardware and its surrounding concrete and will

_ be performed by certified and properly trained examiners. If an area is determined to be suspect during the general visual examination, ANO will take additional actions to ensure the magnitude and extent of deterioration and/or distress is properly characterized for evaluation. To ensure the controls and

' techniques meet this expectation, the Responsible Engineer will periodically witness the performance of these examinations.

3. The general visual examination of the concrete surfaces and the

' detailed visual examination of the suspect areas detected by the general visual examination and the tendon anchorage hardware and its surrounding concrete will be performed in accordance with

- an ANO approved procedure. The examination methods outlined in this procedure will be written to be consistent with the methods approved in the rewrite of Subsection lWL (1997 Addenda) and i

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will be approved by the Responsible Engineer. These approved

. methods will delineate the necessary controls for ensuring these examinations are performed in a manner sufficient to detect evidence of degradation. When the examiner detects evidence of

' degradation, the procedure also requires a detailed visual examination to be performed and compared to established _

reporting and acceptance criteria. The reporting criteria, along with acceptance criteria, will be approved by the Responsible Engineer and will be consistent with the guidance outlined in the American Concrete Institute (ACl) Standard 349.3R-96, i Evaluation of Existing Nuclear Safety-Related Concreta Structure. i if the detailed visual examination cannot be performed for some reason (e.g., access limitation), ANO will evaluate the acceptability of the suspect area. This engineering evaluation will assume the suspect area is inaccessible and will address the ,

requirements outlined in 10CFR50.55a(b)(2)(ix)(E). The engineering evaluation will be approved by the Responsible Engineer.

4. The general and/or detailed visual examination will be performed by certified and properly trained personnel. Personnel performing these visual examinations will be certified in accordance with ANSI N45.2.6, Qualification ofInspection, Examination, and Testing Personnel for Nuclear Power Plants, and by ANO procedure. This level of certification will ensure the capability and visual acuity of the examiners is sufficient to detect evidence of degradation of the concrete structure or the post tensioning system. Prior to performing the examinations, the examiners will be required to successfully complete ANO approved training (i.e., training developed by the Electric Power Research Institute or equivalent) on the proper techniques for examining components subject to the requirements of Subsection lWL. In addition, the examiners will receive site specific training regarding the methods outlined in the approved plant procedure. The site-specific training will be conducted under the direction of the Responsible Engineer and will be held at the beginning of each -

subsequent inservice inspection used to satisfy the applicable requirements of IWL-2410. Successful completion of the above j training will ensure the examiners have a basic working knowledge of the components being examined and the types of degradation to be detected.

5. The ASME Main Committee and the Board of Nuclear Codes and Standards have also determined that Code provisions outlined in IWA-2210 and IWA-2300 were not warranted for the visual examination of concrete surfaces or post tensioning system anchorage hardware or surrounding concrete. Both organizations have approved the rewrite of Subsection lWL that eliminated the .

requirement of IWA-2210 and IWA-2300. This rewrite of

Subsection IWL was published in the 1997 Addenda of the ASME Code,Section XI. The altemative examination methods proposed

, ' by ANO is consistent with the approved rewrite of Subsection IWL

l. and will provide an acceptable level of quality and safety.

l l- 2.2 Altemative Examination l

l The licensee proposes:

To satisfy the requirements of Examination Category L-A (Item Nos. L1.11 and -

L1.12) and Examination Category L-B (Item No. L2.30), ANO will perform the l following:  ;

l l A general visual examination of the accessible concrete surfaces, and a f detailed visual examination of the suspect areas detected by the general j visual examination and the tendon anchorage hardware and its i

surrounding concrete, as applicable, during the ANO-1 and ANO-2 first  ;

containment inspection intervals [ sic). For the first containment l inspection interval, ANO will establish the beginning of the ANO-1 twenty-five year tendon surveillance and the beginning of the ANO-2 twenty year tendon surveillance as the effective start date of the first containment inspection interval for IWL-related activities. When evidence of degradation is detected by the examiners on the accessible concrete surfaces, ANO will perform a detailed visual examination. If a detailed visual examination cannot be performed, an engineering evaluation

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approved by the Responsible Engineer will be provided which will evaluate the suspect area. To ensure the controls and techniques are adequate for detecting evidence of degradation the Responsible Engineer will periodically witness the performance of these examinations.

in addition, each examiner will successfully complete ANO approved training, including site specific, to ensure they have a basic working

( knowledge of the components being examined and the types of degradation to be detected. 1 l

3.0 EVALUATION 1

Table IWL-2500-1, Examination Category L-A (item Nos. L1.11 and L1.12), IWL-2310, and j

. IWL-2510 require a visual (VT-3C) examination of the accessible concrete susiace areas and a l visual (VT-1C) examination of suspect areas. Table IWL-2500-1, Examination Category L-B )

(item No. L2.30), IWL-2310, and IWL-2524 require the performance of a visual (VT-1) i examination of the anchorage hardware'and a visual (VT-10) examination of the surrounding j concrete. The licensee proposes an attemative to these Code requirements for all accessible

. concrete surface areas, and all tendon anchorage hardware and surrounding concrete, which

are subject to these examinations. In its submittal, the licensee states that alternative examination methods are consistent with the methods published in the 1997 Addenda of

, Subsection IWL.  !'

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. The visual examination methods (VT-1C, VT-3C, and VT-1) required by the Code dictate that the examination, and the qualification of the examiners, meet the requirements of IWA-2210 L

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and IWA-2300. However, the requirements specified in these sections were developed for detecting flaws in metal components and, as a result, are more stringent than those that would be required for the detection of degradation of concrete structures. In the 1997 Addenda of Subsection lWL, the requirements of IWA-2210 and IWA-2300 were removed.

.The licensee's submittal states that the personnel performing the examinations will be certified in accordance with ANSI N45.2.6, Qualification ofInspection, Examination, and Testing

.' Personnel for Nuclear Power Plants and will have successfully completed site specific training ,

on proper examination techniques. The Responsible Engineer will periodically witness the

- performance of the examinations. For the type of examinations being performed, the staff finds this provides an acceptable level of quality and safety.

4.0 CONCLUSION

- The staff has 6 valuated the information contained in the licensee's April 1,1999, submittal for ANO-1 and ANO-2. On the basis of the preceding evaluation, the staff concludes that the proposed altemative contained in Altemative Examination 99-0-002 provides an acceptable ,

level of quality and safety and, therefore, the licensee's proposed attemative is authorized l pursuant to 10 CFR 50.55a(a)(3)(i).

Principal Reviewer: M. Kotzalas i

Date: June 2, 1999 l i

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