ML021230184
| ML021230184 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 04/26/2002 |
| From: | Subbaratnam R NRC/NRR/DLPM |
| To: | Thomas Koshy NRC/NRR/DLPM |
| Subbaratnam R, NRR/DLPM, 415-1478 | |
| References | |
| TAC MB2773 | |
| Download: ML021230184 (8) | |
Text
April 26, 2002 MEMORANDUM TO: Thomas Koshy, Acting Chief, Section 2 Project Directorate II Division of Licensing Project Management FROM:
Ram Subbaratnam, Project Manager, Section 2 /RA/
Project Directorate II Division of Licensing Project Management
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI) SENT VIA E-MAIL ON JANUARY 10, 2002, TO CAROLINA POWER & LIGHT COMPANY (CP&L) ON A RELIEF REQUEST FOR THE INSERVICE INSPECTION PROGRAM FOR THE FOURTH 10-YEAR INTERVAL - H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 (HBRSEP2) (TAC NO. MB2773)
Attached is an RAI that was E-mailed to CP&L on January 10, 2002, concerning their August 17, 2001, requests for relief for HBRSEP2.
By copy of this memorandum, I am requesting that this RAI be included in the HBRSEP2 Docket File.
Docket No. 50-261
Attachment:
MEMORANDUM TO: Thomas Koshy, Acting Chief, Section 2 April 26, 2002 Project Directorate II Division of Licensing Project Management FROM:
Ram Subbaratnam, Project Manager, Section 2/RA/
Project Directorate II Division of Licensing Project Management
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI) SENT VIA E-MAIL ON JANUARY 10, 2002, TO CAROLINA POWER & LIGHT COMPANY (CP&L) ON A RELIEF REQUEST FOR THE INSERVICE INSPECTION PROGRAM FOR THE FOURTH 10-YEAR INTERVAL - H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 (HBRSEP2) (TAC NO. MB2773)
Attached is an RAI that was E-mailed to CP&L on January 10, 2002, concerning their August 17, 2001, requests for relief for HBRSEP2.
By copy of this memorandum, I am requesting that this RAI be included in the HBRSEP2 Docket File.
Docket No. 50-261
Attachment:
RAI DISTRIBUTION:
PUBLIC PDII Reading File T. Koshy R. Subbaratnam E. Dunnington B. Bonser, RII ADAMS ACCESS.NO.ML021230184 PM:PDII-S2 LA:PDII-S2 SC:PDII-S2 RSubbaratnam EDunnington T. Koshy 04/08/02 04/08/02 04/08/02 Yes/No Yes/No Yes/No OFFICIAL RECORD COPY
2 REQUESTS FOR ADDITIONAL INFORMATION FOURTH 10-YEAR INSERVICE INSPECTION INTERVAL REQUEST FOR RELIEF CAROLINA POWER AND LIGHT COMPANY H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 DOCKET NUMBER: 50-261 1.
SCOPE By letter dated August 17, 2001, the licensee, Carolina Power and Light (CP&L)Company, submitted multiple requests for relief from the requirements of the ASME Code,Section XI, for the H. B. Robinson Steam Electric Plant, Unit 2. These relief requests are for the fourth 10-year inservice inspection (ISI) interval. Brookhaven National Laboratory (BNL) reviewed the information submitted by the licensee and based on this review, the following information for each relief request is required to complete this evaluation.
2.
REQUESTS FOR ADDITIONAL INFORMATION 2.1 Request for Relief No. RR Pursuant to 10 CFR 50.55a(g)(5), the licensee requested relief from performing Code-required 100% volumetric examination of the pressurizer surge line nozzle inside radius section.
The pressurizer surge line nozzle is examined by VT-2 visual examination during pressure testing each refueling outage. In order for the proposed alternative to be evaluated, please provide the following:
(1)
Please provide sketches or photos with sufficient details so that the staff could determine the impracticality in performing the Code-required surface examinations of the subject welds.
2.2 Request for Relief No. RR Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee requested relief from the Code-required surface, volumetric, and VT-3 visual examination of regenerative heat exchanger vessel head weld, tube sheet-to-shell weld, vessel welds, inlet, outlet, intermediate connecting piping welds, inside radius section, and component supports.
The licensee did not propose any alternatives to the Code-required examinations. VT-2 visual examination during the pressure testing of the heat exchanger pressure-retaining boundary will be performed each refueling outage. In order for the proposed alternative to be evaluated, please provide the following:
(1)
Since the justification for the relief is based on hardship in meeting the ALARA requirements in the regenerative heat exchanger room, please clarify if all welds identified in this relief request are located in this room, specifically the B-J welds and component supports which are referenced for general applications. Also, provide the actual exposure levels estimated for performing the Code-required examinations for each weld included in this relief request.
3 (2)
VT-2 examination during the pressure testing of the regenerative heat exchanger in each refueling outage can be accomplished without exceeding the ALARA limits.
Please explain why all Code-required examinations during refueling outage exceed the ALARA limits.
(3)
The staff has approved similar reliefs; however, the VT-3 visual examinations were performed and was part of the basis for authorizing the alternative. Suggest the licensee review Virginia Electric and Power Companys letter dated December 14, 2000 for North Anna, Unit 2, TAC NO. MB0750 for information required.
2.3 Request for Relief No. RR Pursuant to 10 CFR 50.55a(g)(5), the licensee requested relief from using actual component materials for calibration blocks to be used in ultrasonic testing.
The licensee proposes to use calibration blocks fabricated of similar materials, i.e., SA-533, Grade B, in lieu of SA-302, Grade B, and SA-508 in lieu of SA-336. Also, the licensee proposed to use manually clad reactor vessel calibration blocks that would facilitate comparison of data obtained during the Fourth Ten-Year ISI Interval with examination data obtained during the previous interval. In order for the proposed alternative to be evaluated, please provide the following:
(1)
Based on chemical and physical properties, SA-533, Grade B, is considered to be essentially equivalent to SA-302, Grade B. This parity is also evident in the properties of the SA-336 and SA-508 materials. These materials are considered to be acoustically equivalent, thereby meeting the intent of the Code. Please provide additional details which support this conclusion. Also, why are the Code-required calibration blocks not available ? If this is permanent situation, relief should be pursued with the Code Committee.
(2)
The use of manually clad reactor vessel calibration blocks would facilitate comparison of data obtained during the Fourth Ten-Year ISI Interval with examination data obtained during the previous interval. Please provide additional details supporting the impracticality of using the Code-required calibration blocks.
2.4 Request for Relief No. RR Pursuant to 10 CFR 50.55a(g)(5), the licensee requested relief from the Code-required volumetric examination of the reactor pressure vessel closure head peel segment-to-disk circumferential weld. In order for the proposed relief to be evaluated, please provide the following:
(1)
Accessibility for examination of this weld was not provided in the original plant design, which occurred prior to issuance of the Section XI ISI examination requirements. The closure head peel segment-to-disk weld is completely enclosed within the pattern of Control Rod Drive Mechanism (CRDM) penetrations inside the reactor vessel shroud, such that no portion of the weld is accessible for either surface or volumetric examination. Please provide sketches or photos showing the inaccessibility of the subject weld.
2.5 Request for Relief No. RR Pursuant to 10 CFR 50.55a(g)(5), the licensee requested relief from performing the Code-required volumetric and surface examination of essentially
4 100% of the reactor coolant system piping cold leg circumferential butt welds. In order for the proposed alternative to be evaluated, please provide the following:
(1)
Is there any surrogate welds that could be surface and/or volumetrically examined to assure structural integrity ?
2.6 Request for Relief No. RR-07 - Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee requested relief from performing Code-required volumetric and surface examinations of six RPV nozzle-to-safe end welds.
The licensee proposes to perform volumetric examinations during vessel examinations and a VT-2 examination in accordance with IWA-5242 requirements. In order for the proposed alternative to be evaluated please provide the following:
(1)
Previous examination history supports for Proposed Alternative Examinations in lieu of the Code-required volumetric and surface examinations. No rejectable indications have been identified by examinations conducted during the Third Ten-Year ISI Interval. The dissimilar metal welds, as well as the safe end-to-pipe welds, were examined at the conclusion of the Third Ten-Year Interval for the ASME Code-required volume. Two indications were identified in the hot leg B safe end on the nozzle side, and one indication was identified in the cold leg C nozzle side. These three indications were evaluated in accordance with Code requirements and found to be acceptable. (a) Please provide additional details regarding this conclusion. (b) Please explain why the Code-required volumetric and surface examinations for the Fourth ISI interval face hardship when they were performed during previous ISI intervals. (c) Is there any trending program for the three benign indications noted during Third ISI Interval ?
(2)
Due to the configuration of the RPV nozzles as they penetrate the biological shield wall, the weld area accessible for the Code-required examinations is approximately the top one-third of the weld outside diameter. Explain why the accessible one-third of the weld can not be inspected for the Code-required surface examination.
2.7 Request for Relief No. RR-08 - Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee requested relief from performing Code-required VT-3 visual examination of the reactor vessel interior during each inspection period.
The licensee proposes to perform the Code-required VT-3 visual examination of the reactor vessel interior during the third inspection period and prior to the third inspection period should the reactor vessel lower internals be removed for inspection, maintenance, or repair activities.
In order for the proposed alternative to be evaluated, please provide the following:
(1)
Performance of visual examinations of the reactor vessel interior when the reactor vessel is disassembled for a normal refueling outage provides for an extremely limited examination. The lower internals and core barrel remain installed during a normal refueling outage, which generally limits the examination to the reactor vessel flange surface and inside nozzle surfaces. Please explain how the B-N-2 and B-N-3 inspection activities for the reactor vessel internals during each inspection period are performed without removing the reactor vessel internal components.
5 (2)
Recent performance of these visual examinations during Refueling Outage 20 as part of the Third Ten-Year ISI interval identified no unacceptable conditions or indications that might warrant performance of these examinations on the Code-required periodicity.
This is not adequate to assume that any future inspection will not find an unacceptable condition and an acceptable level of quality will be achieved by the proposed inspection periodicity. Please demonstrate that an Code-required equivalent level of quality will be achieved by the proposed inspection frequency.
2.8 Request for Relief No. RR-10 - Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee requested relief from the Code-required actions to be taken when leakage occurs at a bolted connection other than a gaseous system during the conduct of a system pressure test.
The licensee proposes an alternative similar to Code Case N-566-1. In order for the proposed alternative to be acceptable, please provide the following:
(1)
The use of VT-1 examination in lieu of the Code-required VT-3 visual examination will provide a comparable level of quality and safety. The ASME B&PV Code,Section XI, reference the VT-1 visual examination for pressure retaining bolting. Guidance for performing VT-1 visual examinations of bolting are already incorporated within examination procedures and are considered more stringent than those associated with the VT-3 visual examination. (a) Please identify the Section XI section where VT-1 visual examination for pressure retaining bolting is mentioned. (b) Justify how VT-1 visual examinations of bolting is considered more stringent than those associated with the VT-3 visual examination.
(2)
The proposed alternative does not address actions that should be taken to stop the leakage. Please explain what actions will be taken when the leak from the joint does not stop.
2.9 Request for Relief No. RR-11 - Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee requested relief from performing a system hydrostatic test on Class 3 components at or near the end of each inspection interval.
The licensee will perform a system pressure test at nominal operating pressure on applicable Class 3 systems at the end of the interval during the third inspection period. This system pressure testing will be in lieu of the Code-required hydrostatic pressure testing, and will satisfy the third inspection period system leakage test required by Table IWD-2500-1, Examination Category D-B, Item Nos. D2.10, D2.30, D2.50, and D2.70. Test boundaries will be in accordance with IWD-5240, Boundaries. In order for the proposed alternative to be acceptable, please provide the following:
(1)
Class 3 system leaks generally result from erosion-corrosion, microbiologically induced corrosion, or general corrosion. HBRSEP, Unit No. 2, has existing programs for the prevention, detection, and evaluation of erosion-corrosion and microbiologically induced corrosion. Leakage from general corrosion is readily identified by VT-2 visual examinations performed during system pressure testing conducted at nominal operating pressure. Please provide additional details on the existing activities, specifically how they provide an acceptable level of quality.
6 (2)
Experience has demonstrated that Class 3 system leaks are generally identified with systems at nominal operating pressure, not as a result of hydrostatic test pressure propagating a pre-existing, through-wall flaw. Please discuss the experience that supports this conclusion.
2.10 Request for Relief No. RR-12 - Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee requested relief from extending the pressure retaining boundary during the system leakage tests conducted at or near the end of each inspection interval to Class 1 pressure retaining components within the system boundary.
The Class 1 system boundary during leakage tests will be maintained in a normal, operational alignment with items identified within Table 1 constituting exceptions to the Code-required boundary. The VT-2 visual examination will extend to the Class 1 boundary. In order for the proposed alternative to be evaluated, please provide the following:
(1)
The title of the relief request refers to hydrostatic test and the relief is requested for system leakage tests. The basis for relief discusses for hydrostatic tests while the conclusion and the proposed alternative refer to system leakage tests. Please clarify these discrepancies.
(2)
The HBRSEP, Unit No. 2, design of Class 1 vents and drains typically consists of a single isolation valve with a capped end that constitutes the Class 1 system boundary.
Please clarify how the draining and venting operations are performed when the ends are capped.
(3)
The HBRSEP, Unit No. 2, design also requires substantial effort to extend the Class 1 system boundary where check valves or non-redundant components serve as the first system isolation from the reactor coolant system. Such configurations may require check valve disassembly or other temporary configurations to achieve test pressures at upstream piping and valves. Since the Class 1 system hydrostatic testing is performed in Mode 3, these temporary configurations could conflict with Technical Specification requirements. Please provide the actual conditions of those Class 1 lines associated with check valves and how many of these temporary configurations conflict with the technical specifications.
(4)
In the proposed alternative, items within Table 1 will be visually examined for evidence of leakage during system leakage testing without being pressurized. Please clarify the status of the subject valves in each Class 1 system.
2.11 Request for Relief No. RR-16 - Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee requested relief from scheduling the examinations for RPV shell-to-flange and head-to-flange welds.
Examination of the RPV shell-to-flange and head-to-flange welds will be deferred to the end of the inspection interval without conducting partial examinations from the flange face. In order for the proposed alternative to be acceptable, please provide the following:
7 (1)
The Code-requirements included in the relief request are confusing. Item no. B1.40 requires both surface and volumetric examinations. Also, this does not require partial examination during the first period. Please clarify.
(2)
HBRSEP, Unit No. 2, plans to examine 100% of the RPV shell-to-flange weld and 100%
of the threads in the flange utilizing automated techniques that will eliminate or greatly reduce worker radiation exposures associated with the examination. (a) Please clarify what thread in the flange are examined. (b) Please provide an estimate of the worker radiation exposures associated with the examination (current vs. proposed).
(3)
Examination of the RPV head-to-flange weld involves the potential for significant worker radiation exposure that are not commensurate with the benefits achieved from performance of the Code-required examinations. Please quantify what significant worker radiation exposure.
(4)
The relief is requested under 10 CFR 50.55a(a)(3)(i). The basis for relief is based on hardship due to higher worker radiation exposure. Explain how the proposed alternative will provide an acceptable level of quality and safety.
2.12 Request for Relief No. RR-17 - Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee requested relief from performing welding and brazing procedure qualification requirements by the Code.
The licensee will use the welding and brazing procedure qualification requirements stated in Code Case N-573. In order for the proposed alternative to be evaluated, please provide the following:
(1)
The first bullet stated that the owner performed the procedure qualification test will certify, by signing the PQR, that testing was performed in accordance with Section XI.
The Code Case refers to Section IX, Welding and Brazing Qualification. Clarify.