3F0608-05, Response to Request for Additional Information Regarding Relief Requests 07-001-SS, Revision 0, Alternate Criteria for the Reactor Vessel Support Skirt to Perform Limited VT-3 Visual Examination on 3 Areas 120 Degrees Apart .

Response to Request for Additional Information Regarding Relief Requests #07-001-SS, Revision 0, Alternate Criteria for the Reactor Vessel Support Skirt to Perform Limited VT-3 Visual Examination on 3 Areas 120 Degrees Apart .

ML081720130
Person / Time
Site:	Crystal River
Issue date:	06/05/2008
From:	Cahill S Progress Energy Florida
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
07-001-SS, Revision 0, 3F0608-05, TAC MD7737
Download: ML081720130 (11)

Text

k Progress Energy Crystal River Nuclear Plant Docket No. 50-302 Operating License No. DPR-72 Ref: IOCFR50.55a June 5, 2008 3F0608-05 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

Subject:

Crystal River Unit 3 - Response to Request for Additional Information Regarding Relief Requests #07-001-SS, Revision 0, Alternate Examination Criteria for the Reactor Vessel Support Skirt to Perform Limited VT-3 Visual Examination on 3 areas 120 Degrees Apart on the Inside Surface in Accordance with 10 CFR 50.55a(a)(3)(i), TAC No.

MD7737

Reference:

Crystal River Unit 3 to NRC letter, 3F1207-04, dated December 21, 2007, "Crystal River Unit 3 - Inservice Inspection Program Plan, Ten Year Update," Accession No. ML073650362

Dear Sir:

Pursuant to 10 CFR 50.55a(a)(3)(i), Florida Power Corporation (FPC) doing business as Progress Energy Florida, Inc., Crystal River Unit 3 (CR-3) is hereby submitting the response to a Nuclear Regulatory Commission (NRC) request for additional information (RAI) received by email on May 14, 2008. This request for additional information is based on Relief Request #07-001-SS, Revision 0.

In addition, Attachment 3 is providing a revised page 7-14 of the Ten Year Inservice Inspection (ISI)

Program Plan for the Fourth Interval, as line item El.30 was discovered missing during a review subsequent to the referenced submittal.

Regulatory commitments are identified in Attachment 4.

If you have any questions regarding this submittal, please contact Dennis Herrin, Acting Supervisor, Licensing and Regulatory Programs at (352) 563-4633.

Sincerely, SteC ahilll Engineering Manager SJC/par Attachments: 1. Response to Request For Additional Information

2. Drawings

3. Revised Page 7-14 of the Ten Year ISI Inspection Program Plan

4. List of Regulatory Commitments xc: NRR Project Manager Regional Administrator, Region II Senior Resident Inspector Progress Energy Florida, Inc.

,Au47 Crystal River Nuclear Plant 15760 W. Powerline Street Crystal River, FL 34428

PROGRESS ENERGY FLORIDA, INC.

CRYSTAL RIVER UNIT 3 DOCKET NUMBER 50 - 302 / LICENSE NUMBER DPR - 72 ATTACHMENT 1 Response to Request for Additional Information

U. S. Nuclear Regulatory Commission Attachment 1 3F0608-05 Page 1 of 2 Response to Request for Additional Information NRC Request (1) Relief Request #07-001-SS, Revision 0 The American Society of Mechanical Engineers (ASME) Code, Section Xl, Examination Category F-A, Item F.130 requires a 100% VT-3 visual examination of weld and mechanical connections at intermediate joints in multi-connected integral and non-integralsupports, as defined by Figure IWF-1300-1. The licensee has proposed performing an alternative VT-3 visual examination on 10% of the reactor vessel (RV) support skirt for the fourth 10-year inspection interval for CR3. The proposed approach utilizes the identical approach from previous inspection intervals. The RR (98-003-11) for the third CR3 10-year ISI interval was authorized in the Safety Evaluation Report dated August 5, 1999. Relief was requested based on the radiation conditions below the RV, which would result in significant radiation exposure to inspection and support personnel. Because there have been substantial improvements in inspection techniques since the previous inspection interval, the staff requests that the licensee address the potential for increase in visual examination of the RV skirt through the use of improved state-of-the-artinspection techniques.

FPC Response Even with the improvements in the inspection techniques since the last inspection period, there are dose and other limitations, due to the physical configuration of under vessel area, which prevent a 100% VT-3 visual inspection from being performed. The area under the reactor vessel is a high radiation area, and the Crystal River Unit 3 (CR-3) commitment to ALARA requires minimization of time spent in this area.

The outside surface of the weld is restricted from access by a welded seal plate in the refueling cavity.

This plate would have to be removed and a person would have to be lowered down between the reactor vessel and the shield wall to remove the insulation and perform the inspection of the support skirt weld. An optional access point for the inspection would be to remove the concrete plug allowing access from below. This option involves the removal of 42 cubic feet of 5000 psi concrete, which is further complicated by the fact that the plug is overhead and there is insufficient room for jackhammers to be used. Therefore, only the inside surface of the support skirt weld is reasonably accessible, which automatically limits the examination to no more than 50%.

Additionally, removing the insulation panels on the bottom of the reactor vessel is not easily performed due to the number of incore monitoring tubing interferences in the bottom head. The panels are 30 inches in length and the physical shape of each panel is such that there would be significant difficulty in maneuvering them in the cramped area without potentially impacting one or more of the thin wall incore monitoring tubing. Since any leakage in one of these thimbles would be un-isolable, any activity that could potentially cause potential leakage at this location should be avoided.

The areas inspected are reviewed each time to note any trends of degradation. Any mechanism which could damage the vessel would be evident at these three locations examined and not confined to small areas around the vessel. If the entire vessel shifted, then the damage to the bolting, support skirt or associated weld would be visible over a majority of the examination area.

It is expected that more than 10% of the inside support skirt weld is inspected during the required VT-3 visual examination, but there is no accurate method of measurement. Therefore, CR-3 cannot commit to a larger percentage of the inspection area. The area is too confined to get a measurement device in place. The last time this examination was performed was in conjunction with the bare metal visual inspection of the bottom reactor vessel head during Refuel Outage 13 in 2003.

U. S. Nuclear Regulatory Commission Attachment 1 3F0608-05 Page 2 of 2 CR-3 will perform a VT-3 examination of the reactor vessel support skirt weld, to the extent practical, when maintenance or other activities remove the insulation covering the support skirt weld. This can be performed in conjunction with the bare metal visual inspection of the bottom reactor vessel head.

The inspection is performed with a pole mounted camera and enables a long reach around the circumference of the support skirt.

In summary, Florida Power Corporation recognizes that inspection and examination techniques have improved in the last ten years, but considers the relief request as valid due to the same concerns that were the basis for the previous interval relief requests from this requirement. It is expected that shifts in the reactor vessel, due to undetected cracks in the support skirt weld, would be noted in the VT-3 examination of those areas within the inspection scope.

PROGRESS ENERGY FLORIDA, INC.

CRYSTAL RIVER UNIT 3 DOCKET NUMBER 50 - 302 / LICENSE NUMBER DPR - 72 ATTACHMENT 2 Drawings

REACTOR PRESSURE VESSEL MK36 TO 81.121 IE SECTION X NDE PROGRAMI INSTRUMENTATION CR3-P-SK-lACI 2 NOZZLES N/A

PROGRESS ENERGY FLORIDA, INC.

CRYSTAL RIVER UNIT 3 DOCKET NUMBER 50 - 302 / LICENSE NUMBER DPR - 72 ATTACHMENT 3 Revised Page 7-14 of the Ten Year ISI Inspection Program Plan

U. S. Nuclear Regulatory Commission Attachment 3 3F0608-05 Page 1 of 1 ISIPrograin Plan Crystal River Unit 3, Fourth Interval TABLE 7.1-1 INSERVICE INSPECTION

SUMMARY

TABLE Examination Category (with Item Description Exam Total Number of Relief Request/ Notes Examination Category Number Requirements Components TAP Number Description)

E-A El. 11 Containment Vessel Pressure Retaining Boundary General Visual Liner Plates: 26 4 Containment Surfaces Accessible Surface Areas Penetrations: 155 Attachments: 867 EL.11 Containment Vessel Pressure Retaining Boundary Visual, VT-3 7 4 Bolted Connections, Surfaces E1.12 Containment Vessel Pressure Retaining Boundary Visual, VT-3 Sump: 1 5 Wetted Surfaces of Submerged Areas Penetrations: 2 Attachments: 0 EI.30 Moisture Barriers General Visual I E-C E4.11 Containment Surface Areas -Visible Surfaces Visual, VT-l1 0 6 Containment Surfaces E4.12 Containment Surface Areas -Surface Area Grid Volumetric 0 7 Requiring Grid Line Intersections and Minimum (Thickness)

Augmented Examination Wall Thickness Locations 7-14 PENO1. G03 Revision 0

PROGRESS ENERGY FLORIDA, INC.

CRYSTAL RIVER UNIT 3 DOCKET NUMBER 50 - 302 / LICENSE NUMBER DPR - 72 ATTACHMENT 4 List of Regulatory Commitments

U. S. Nuclear Regulatory Commission Attachment 4 3F0608-05 Page 1 of 1 LIST OF REGULATORY COMMITMENTS The following table lists regulatory commitments identified by Florida Power Corporation (FPC), in this document. Any other actions discussed in the submittal represent intended or planned actions by FPC.

They are described to the NRC for the NRC's information and are not regulatory commitments. Please notify the Supervisor, Licensing and Regulatory Programs of any questions regarding this document.

Regulatory Commitments Due Date CR-3 will perform a VT-3 examination of the reactor vessel support skirt weld, to the 09/30/2008 extent practical, when maintenance or other activities remove the insulation covering the support skirt weld.