ML14191A591

Forwards Request for Addl Info on Inservice Insp Program Plan for Plant.Response Requested by 920215

ML14191A591
Person / Time
Site:	Robinson
Issue date:	01/13/1992
From:	Dan Dorman Office of Nuclear Reactor Regulation
To:	Eury L Carolina Power & Light Co
References
TAC-M81310 NUDOCS 9201150205
Download: ML14191A591 (8)

Text

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January 13, 1992 DISTRIBUTION ee next page Docket No. 50-261 Mr. Lynn W. Eury Executive Vice President Power Supply Carolina Power & Light Company Post Office Box 1551 Raleigh, North Carolina 27602

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION ON THE INSERVICE INSPECTION PROGRAM PLAN FOR H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 (TAC NO. M81310)

The NRC staff, with assistance from its contractor, Idaho National Engineering Laboratory, is reviewing and evaluating the Third Ten-Year Inservice Inspection (ISI) Program Plan and requests for relief from the ASME Code,Section XI requirements for H. B. Robinson, Unit No. 2. The staff requires additional information in order to complete its review. You are requested to respond to the enclosed list of questions by February 15, 1992, to facilitate timely completion of the staff's review. In addition, to expedite the process, you are requested to send one copy of your response directly to the staff's contractor at the following address:

Boyd W. Brown EG&G Idaho, Inc.

INEL Research Center 2151 North Boulevard P.O. Box 1625 Idaho Falls, ID 83415-2209 Sincerely, Orignal signed by:

Daniel H. Dorman, Acting Project Manager Project Directorate II-1 Division of Reactor Projects -

I/II Office of Nuclear Reactor Regulation cc:

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LTR TO EURY ROBINSON 9201150205 920113 PDR ADOCK 05000261 0

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DISTRIBUTION Docket File NRC PDR Local PDR S. Varga 14-E-4 G. Lainas 14-H-3 L. Reyes RH E. Adensam 14-8-20 P. Anderson 14-B-20 D. Dorman 14-8-20 C. Y. Cheng 7-D-4 OGC 15-B-18 ACRS (10)

P-315 PD21 Reading File cc:

Robinson Service List

Mr. L. W. Eury H. B. Robinson Steam Electric Carolina Power & Light Company Plant, Unit No. 2 cc:

Mr. H. Ray Starling Mr. Dayne H. Brown, Director Manager - Legal Department Department of Environmental, Carolina Power & Light Company Health and Natural Resources P. 0. Box 1551 Division of Radiation Protection Raleigh, North Carolina 27602 P. 0. Box 27687 Raleigh, North Carolina 27611-7687 Mr. H. A. Cole Special Deputy Attorney General Mr. Robert P. Gruber State of North Carolina Executive Director P. 0. Box 629 Public Staff - NCUC Raleigh, North Carolina 27602 P. 0. Box 29520 Raleigh, North Carolina 27626-0520 U.S. Nuclear Regulatory Commission Mr. C. R. Dietz Resident Inspector's Office Vice President H. B. Robinson Steam Electric Plant Robinson Nuclear Department Route 5, Box 413 H. B. Robinson Steam Electric Plant Hartsville, South Carolina 29550 P. 0. Box 790 Hartsville, South Carolina 29550 Regional Administrator, Region II U.S. Nuclear Regulatory Commission Mr. Heyward G. Shealy, Chief 101 Marietta Street Bureau of Radiological Health Suite 2900 South Carolina Department of Health Atlanta, Georgia 30323 and Environmental Control 2600 Bull Street Mr. Ray H. Chambers, Jr.

Columbia, South Carolina 29201 General Manager H. B. Robinson Steam Electric Plant P. 0. Box 790 Hartsville, South Carolina 29550

Request for Additional Information -

Third 10-Year Interval Inservice Inspection Program Plan

1. Scope/Status of Review Throughout the service life of a water-cooled nuclear power facility, 10 CFR 50.55a(g)(4) requires that components (including supports) that are classified as American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Class 1, Class 2 and Class 3 meet the requirements, except design and access provisions and preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. This section of the regulations also requires that inservice examinations of components and system pressure tests conducted during the successive 120-month inspection interval comply with the requirements in the latest edition and addenda of the Code incorporated by reference in 10 CFR 50.55a(b) on the date 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The components (including supports) may meet requirements set forth in subsequent editions and addenda of the Code that are incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein. The Licensee, Carolina Power and Light Company (CP&L), has prepared the H. B. Robinson Nuclear Project, Unit 2, Third Ten-Year Inservice Inspection (ISI) Program Plan to meet the requirements of the 1986 Edition of the ASME Code,Section XI, except that, as allowed by 10 CFR 50.55a(b)(2)(ii), the extent and frequency of examination for Code Class 1, Category B-J piping welds has been determined by the 1974 Edition through Summer 1975 Addenda (74S75).

As required by 10 CFR 50.55(g)(5), if the licensee determines that certain Code examination requirements are impractical and relief is requested, the licensee shall submit information to the Nuclear Regulatory Commission (NRC) to support that determination.

The staff has reviewed the available information in the H. B. Robinson Nuclear Project, Unit 2, Third Ten Year Interval ISI Program Plan, Revision 0, submitted August 1, 1991, including the requests for relief from the ASME Code Section XI requirements that the Licensee has determined to be impractical.

2. Additional Information Required Based on the above review, the staff has concluded that the following information and/or clarification is required in order to complete the review of the ISI Program Plan:

A.

It appears that the Containment Spray system has been completely excluded from volumetric examination based on wall thickness.

Paragraph 10 CFR 50.55a(b)(2)(iv) requires that ASME Code Class 2 piping welds in the Residual Heat Removal (RHR), Emergency Core 1

Cooling (ECC), and Containment Heat Removal (CHR) be examined.

Please confirm that the Containment Spray system, and all other portions of the ECC, RHR, and CHR systems, will be included in the 7.5% examination sample.

B.

In the H. B. Robinson, Unit 2, Third Ten-Year ISI Program Plan it has been stated that no effort has been made to identify individual welds in the ten year plan where restrictions (geometric configuration and surface conditions that are associated with fitting-to-fitting and fitting-to-pipe weld joints) exist. These welds will be examined to the extent practical. If an ASME Section XI Code requirement cannot be performed, the Licensee is required to submit documentation demonstrating the basis for the determination of impracticality to the NRC. CP&L has not identified specific welds that are not receiving the Code-required examinations or, in those cases where a partial examination is being performed, the percentage of Code required examination that can and will be completed. In those cases where these generalities exist (e.g., Relief Requests #6,

1. 7, #11, #14, and #15), please provide the specific information necessary for evaluation.

C.

Augmented examinations have been established by the NRC when added assurance of structural reliability is deemed necessary. Examples of documents that address augmented examination are:

(1) Branch Technical Position MEB 3-1, "High Energy Fluid Systems, Protection Against Postulated Piping Failures in Fluid Systems Outside Containment;"

(2) Regulatory Guide 1.150, "Ultrasonic Testing of Reactor Vessel Welds During Preservice and Inservice Examinations;"

and (3) Regulatory Guide 1.14, "Reactor Coolant Pump Flywheel Integrity."

Paragraph F-2300(d) of the H. B. Robinson ISI Program Plan references Regulatory Guides 1.14 and 1.150 as applicable documents. Address the degree of compliance with the examples given above and also discuss any other augmented examinations that may have been incorporated in the H. B. Robinson Nuclear Project, Unit 2, Third 10-Year Interval Inservice Inspection Program Plan.

As stated in the Program Plan, the surface examination discussed in Regulatory Guide 1.14 will not be performed due to painted surfaces. A Licensee Event Report was prepared and issued on July 18, 1990, for another utility because of a failure to perform the surface examination of painted RCP flywheels. At least one other plant is using eddy current (ET) testing with a saturation probe as an acceptable surface examination technique. Discuss the implementation of this Regulatory Guide and the associated examinations.

2

D.

Relief Request #1:

The Licensee has requested total relief from volumetric examination of the Class 1 pressurizer nozzle inside radius sections. Although the Licensee may not have confidence in this examination for determining the condition of the subject components, sufficient information has not been supplied to establish that the Code-required volumetric examination is impractical to perform. If relief is to be considered, sufficient technical justification demonstrating impracticality must be provided. What attempts have been made to obtain construction drawings, select transducers, and perform the Code-required volumetric examination of the nozzle inner radius sections? If the full Code-required volumetric examination cannot be completed, describe a "best effort" volumetric examination that could and would be performed. The Program Plan states that an alternative visual examination will be performed "only if the pressurizer is opened for other types of examinations or for maintenance purposes."

Estimate how often the pressurizer would be opened under these circumstances. What does a "visual examination...

to the extent practical" represent in terms of percentage of inner radius sections examined?

E.

Relief Request #4:

Relief is requested from the surface examination of 100% of the primary nozzle safe end welds. The Licensee's proposed alternative is to perform surface examinations to the extent practical.

Because the consequences of a failure in this area are severe, the Code-required examinations are considered essential. Please provide an estimate of the percent that can and will be examined for each of the welds for which relief is requested.

Other utilities with similar plant designs have proposed a volumetric examination of the nozzle safe ends and dissimilar metal welds from the inside diameter using the automated reactor vessel tool as an alternative to the Code-required surface examination. This proposed alternative examination has been considered acceptable per IWA-2240, provided the following conditions are met (other utilities have met these conditions):

(1) The remote volumetric examination includes the entire weld volume and heat affected zone instead of only the inner one-third of the weld; and (2) The ultrasonic testing instrumentation and procedure are demonstrated to be capable of detecting OD surface-connected defects, in the circumferential orientation, in a laboratory test block. The demonstration sample defects must be cracks and not machined notches.

Discuss CP&L's intentions with regard to an acceptable alternative for the surface examination.

F.

Relief Requests #6 and #15:

Relief is requested from performing the Code-required surface examinations of certain circumferential and longitudinal pipe welds in Class 1 and 2 systems. The Licensee proposes a full volumetric examination of the weld area 3

be performed in lieu of the required surface examination. This proposal could be considered an acceptable alternative, as allowed by IWA-2240, provided the same conditions described in Item E above are met. In addition, the performance demonstration samples should have weld surface geometries representative of the actual plant weld conditions. Confirm that the volumetric examination will include the entire weld volume and heat affected zone, and that the UT instrumentation and procedure are demonstrated to be capable of detecting OD surface-connected defects.

G.

Relief Request #7:

Relief is requested from performing 100% of the Code-required volumetric examination of the 900 elbow welds in the crossover legs of the reactor coolant system. This request for relief contains no discussion of, or justification for, the granting of relief based on impracticality. An electroslag weld can be difficult to examine ultrasonically, but this does not explain the impracticality of examining the associated circumferential welds. Similar plants are successfully performing these examinations on cast stainless steel.

The staff has continued to monitor the development of new or improved examination techniques. As improvements in these areas are achieved, the staff is requiring that these new techniques be made part of the ISI examination procedures. Discuss attempts that have been made by CP&L to examine these cast elbow welds and any other cast stainless steel components ultrasonically.

H.

Relief Requests #9 and #10:

Relief is requested from 100%

volumetric examination of Class 1 integrally welded attachments for piping and pumps. A surface or combination of volumetric and surface examinations are proposed. The ASME Code requirement is a volumetric or surface examination as applicable. It appears that CP&L is interpreting the Code to require volumetric and surface examinations. This same situation was addressed in Code Interpretation question XI-1-89-11, submitted to the ASME Code Committee and issued on February 6, 1989. Therefore, it is the opinion of the staff that relief is not required if one or more examination methods are employed and essentially 100% of the length of the attachment weld is subject to examination. Discuss the specific Code requirement for which relief is required.

I.

Relief Requests #2, #11 and #14:

Relief Requests #2, #11 and #14 appear to be asking for relief for the same welds. Relief Request

1. 2 seeks total relief from any examinations; Relief Requests #11 and #14 portray a best effort, with visual and surface examinations as supplements. Please provide clarification of why these three relief requests are conflicting along with an estimate of the percentage of the Code-required volumetric examination that can and will be performed on each of the subject welds for which relief is requested. In each case describe the impracticality or "geometric configuration" which is preventing the Code-required examination from being performed.

J.

Relief Request #14 states that volumetric examination of the regenerative heat exchanger tubesheet-to-shell weld will be performed "to the extent practical."

Examination Category C-A 4

requires that the vessel areas selected for the initial examination be reexamined over the service lifetime of the component. The specific geometric interferences and the practical extent of examination should have been identified by the third interval. Provide an estimate of the percentage of the Code required volumetric examination that can and will be completed.

Is it CP&L's proposed alternative to examine the accessible portions of all three welds (Weld Nos. 3, 7, and 11) or the accessible portions of one weld?

K.

Relief Request #12:

Relief is requested from the volumetric examination requirements for the steam generator Class 1 nozzle inner radii.

In the Licensee's submittal, the proposed alternative states that a visual examination will be performed if the steam generators are opened for maintenance or eddy current examination. Why is CP&L making the proposed alternative conditional? Regulatory Guide 1.83 necessitates tubing inspections every 12 to 24 months provided a reduced inspection plan is not in effect. Confirm CP&L's commitment to performing the proposed alternative examination.

L.

Relief Request #13:

Relief is requested from performing the volumetric examination of the reactor coolant pump casing welds.

ASME Code Case N-481 specifically addresses the issue of alternative examination requirements for cast austenitic pump casings, and is expected to be included in Revision 9 of Regulatory Guide 1.147. Please discuss the applicability of using this Code Case or the alternative of performing the Code-required volumetric examination of the pump casing welds if the pump is disassembled for maintenance.

M.

Relief Request #16 and #17:

Relief Request #16 is seeking to use one calibration block for examination of the reactor coolant piping. It is noted that CP&L is intending to use Code Case N-461, "Alternative Rules for Piping Calibration Block Thickness,"

in Relief Request #17.

This Code Case was approved by the NRC in Revision 8 of Regulatory Guide 1.147 with the stipulation that "thickness measurements and weld joint contour of the pipe/component must be known and used by the inspector who conducts the UT examination."

Confirm that CP&L will use the added NRC stipulation with Code Case N-461 for Relief Request #17.

Discuss why this same Code Case is not applied to Relief Request #16.

If a Code Case is being implemented in accordance with the requirements of Regulatory Guide 1.147, a relief request is not necessary.

However, the Licensee is required to report the intended use to the NRC in the program plan.