IR 05000302/2011009

IR 05000302-11-009, on 01/01-04/22/2011; Crystal River Unit 3; Steam Generator Replacement Inspection

ML111330350
Person / Time
Site:	Crystal River
Issue date:	05/12/2011
From:	Mark Franke NRC/RGN-II/DRS/EB2
To:	Franke J Florida Power Corp, Progress Energy Florida
References
IR-11-009
Download: ML111330350 (328)

Text

May 12, 2011

SUBJECT:

CRYSTAL RIVER NUCLEAR PLANT - STEAM GENERATOR REPLACEMENT INSPECTION PROGRESS REPORT 05000302/2011009

Dear Mr. Franke:

On April 22, 2011, the U.S. Nuclear Regulatory Commission (NRC) completed inspections at

your Crystal River Unit 3 Nuclear Plant in accordance with NRC Inspection Procedure (IP)

50001, Steam Generator Replacement Inspection. The enclosed inspection report documents

inspection results, which were discussed on April 28, 2011, with you and members of your staff.

The inspections examined activities conducted under your license as they relate to safety and compliance with the Commission's rules and regulations and with the conditions of your license.

The inspectors reviewed selected procedures and records, observed activities, interviewed

personnel, and conducted plant walk downs, including visual examination of accessible portions

of the containment building structure.

In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and its

enclosure will be available electronically for public inspection in the NRC Public Document

Room or from the Publicly Available Reco rds (PARS) component of the NRC's Agencywide Documents Access and Management System (ADAMS

). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/

Mark E. Franke, Chief Operations Branch 2

Division of Reactor Safety

Docket No. 50-302

License No. DPR-72

Enclosures:

1: Inspection Report 05000302/2011009

w/Attachment: Supplemental Information

2: Licensee Question Tracking Database

REGION II Docket No.: 50-302

License No.: DPR-72

Report No.: 05000302/2011009

Licensee: Progress Energy (Florida Power Corporation)

Facility: Crystal River Unit 3

Location: Crystal River, FL

Dates: January 1, 2011 through April 22, 2011

Inspectors: R. Carrion, Senior Reactor Inspector L. Lake, Senior Reactor Inspector

Approved by: Mark E. Franke, Chief, Operations Branch 2

Division of Reactor Safety

Enclosure 1

SUMMARY OF FINDINGS

IR 05000302/2011009; 01/01-04/22/2011; Crystal River Unit 3; Steam Generator Replacement

Inspection

This report covered an infrequently performed Steam Generator Replacement Project (SGRP)inspection performed by regional reactor inspectors from January 1, 2011, through April 22, 2011. This report also includes a list of issued inspection reports and a summary of the SGRP inspections performed prior to December 31, 2010. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, "Reactor

Oversight Process," Revision 4, dated December 2006.

A. NRC-Identified

& Self-Revealing Findings No findings were identified.

B. Licensee-Identified Violations

None.

REPORT DETAILS

Background

The licensee scheduled the replacement of its steam generators during Crystal River Unit 3 (CR3) Refueling Outage 16, which began in September 2009. The steam generators are

housed in the reactor containment building. In preparation for the steam generator

replacement, the licensee evaluated options for moving the existing steam generators out of the

containment building and moving the new steam generators into the containment building. The

licensee decided to make a construction opening in the containment building wall, approximately forty feet directly above the equi pment hatch, to facilitate this evolution.

Fabricating the opening in the containment building wall included preparing the containment

building by detensioning its pre-stressed tendons and then removing the concrete with high

pressure water (a process known as hydro-demolition), removing the rebar and tendons from

the area of the construction opening, and cutting the containment liner plate. A concrete

delamination in Bay 3-4 of the containment structure was discovered while creating the SGR

opening in October 2009. The licensee determined that the root cause of the delamination was

related to the scope and sequence of the tendon detensioning process.

The licensee's containment building repair plan included:

(1) additional detensioning of

containment;

(2) removal of delaminated concrete;

(3) installation of reinforcement, including

radial reinforcement through the delamination plane;

(4) placing of new concrete;

(5) retensioning containment; and

(6) post-repair confirma tory system pressure testing. In early 2011, the licensee had completed repair steps 1 through 4 and was in the process of

retensioning the containment. On March 14, 2011, during the final stages of the re-tensioning

process, the licensee had indications that a new delamination occurred in Bay 5-6 of the

containment structure.

Since September 2009, and through the end of this inspection period, Crystal River Unit 3 has

remained shutdown, a mode of operation where containment building operability is not required.

The purpose of this inspection report is to document all inspection activities performed related to

the steam generator replacement project for Unit 3 containment restoration activities including

repairs due to the concrete delamination identified in October 2009.

OTHER ACTIVITIES

[OA]

4OA5 Steam Generator Replacement Inspection (IP50001)

.1 SGRP Inspection Activities through December 31, 2010

Inspection of the licensee's SGRP began in September 2009 when the inspectors

reviewed the preparations for heavy load movement and lifting and started the review of

the design modifications associated with the project. Inspection of the licensee's SGRP

continued in the fourth quarter of 2009 and throughout 2010. Results of the SGRP

inspections are documented in the quarterly integrated resident inspector reports. The

following is a summary of the activities inspected. Details of the inspections can be

found in the following inspection reports:

Inspection Report ADAMS ML # Report Section 05000302/2009004 ML093030165 4OA5.2 05000302/2009005 ML100250014 4OA5.2 05000302/2010002 ML101170619 4OA5.3 05000302/2010003 ML102090239 4OA5.2 05000302/2010004 ML103020127 4OA5.3 05000302/2010005 ML110270190 4OA5.2 Design and Planning The inspectors reviewed and examined the SGRP activities and compared them to the

requirements of the American Society of Mechanical Engineers (ASME) Code. The

inspectors reviewed Engineering Change (EC) 63038, Replacement Once Through

Steam Generators (ROTSGs or RSGs), which included the design changes, analyses, evaluations, safety analyses, 10 CFR Part 50.59 change evaluation, configuration, materials, implementation, and post-modification testing acceptance. The inspectors

reviewed EC 62500, RCS Hot Leg Cutting and Welding, EC 63016, Containment

Opening; EC 63025, Main Feedwater Flow Accelerated Corrosion (FAC) Pipe

Replacement, EC 63026, RCS Cold Leg Cutting and Welding, EC 63027, Secondary

Side Large Bore Pipe Cutting and Welding, EC 63034, Structural Interferences, and EC 63039, Replacement Steam Generator Anchorage. The inspectors also reviewed

selected work order (WO) packages prepared for the construction and implementation of

the ECs to determine whether appropriate work processes and quality control hold

points were implemented.

Steam Generator Removal and Replacement During the hydro-demolition process to create the construction opening in the

containment wall, the licensee identified concrete cracks/separations. The concrete

separations were located within the entire perimeter of the opening. An NRC Special

Inspection Team was chartered to inspect the separation issues. Results of the Special

Inspection, including the licensee's root cause analysis, are documented in NRC

Inspection Report 05000302/2009007 (ML1028610261). The licensee evaluated the

containment wall cracks to modify the hor izontal transfer system (HTS) supporting structures. Prior to the removal of the original steam generators (OSGs), the inspectors

reviewed, observed, and evaluated the associated temporary and permanent

modifications of the cutting, disconnecting, and the providing of temporary supports for

the OSGs and cutoff piping. The inspectors observed lifting, rigging, downending and

upending, and transporting of the OSGs, RSGs, and associated equipment; machining

and preparations of the existing piping for the connections to the RSGs; welding and

non-destructive examination (NDE) activities; and the radiological safety plan for the

temporary storage and disposal building of the retired steam generators. The inspectors

reviewed and observed the major structural modifications. The inspectors observed the

licensee performance inspection of the steam generator hold-down bolts to verify that

the bolts were acceptable to hold down the RSGs after the OSGs were moved from their

cubicles. During the steam generator (SG) removal and replacement, the inspectors

observed licensee activities associated with controls for excluding foreign material, including the primary and secondary side of the steam generators and in the related

RCS openings, and the establishment of operating conditions including defueling, RCS

draindown and system isolation. The inspecto rs also reviewed procedures, examination results, modification packages, and WO packages related to the modifications, including the construction opening steel containment vessel (SCV)reinstallation, to ensure compliance with the requirements of the ASME Code.

RSG Fabrication, Preservice Inspection, and Baseline Inspection The inspectors reviewed records associated with the materials, fabrication, examination, and testing for the RSGs, and replacement hot leg piping subassemblies ("Candy

Canes"), to verify compliance with the ASME Code. The inspectors also reviewed

documentation and interviewed plant personnel regarding the pre-service and baseline

testing of RSG tubing. The inspectors also reviewed documentation regarding the

manufacture of the RSG tubing, including heat treatment records and nonconformance

reports.

Welding The inspectors reviewed a sample of welding activities associated with the installation of

the RSGs to evaluate compliance with licensee/contractor procedures and the applicable

ASME Code. The inspectors reviewed joint configuration drawings, welding procedures, welding specifications, welding procedure qualifications, welder qualification records, weld data records, nuclear condition reports (NCRs), and post-weld heat treatment

procedures.

Non-Destructive Examination The inspectors reviewed the NDE procedures, calibration and examination reports, and

NCRs, and observed in-process NDEs, including liquid penetrant examinations (PTs),

magnetic particle examinations (MTs), radi ographic examinations (RTs), and ultrasonic examinations (UTs), and compared them to the requirements of the procedures and the ASME Code for the construction, pre-service, and baseline inspections.

Containment Construction Opening and Closure - Steel and Concrete Containment The inspectors reviewed the licensee's activities associated with the concrete removal

and the removal and restoration of the steel containment liner plate (SCLP) for the

containment construction hatch opening, as detailed in the EC 63016, Containment

Opening. The inspectors reviewed the plans for the cutting and restoration of the SCLP

for the construction opening and compared post-testing requirements to the applicable

ASME Code. The inspectors observed the hydro-demolition of concrete for the

containment construction opening and reviewed the WO packages for the cutting of the

liner plate to verify that the steps had been completed and documented. The inspectors

also reviewed the welding procedures, procedure qualification records, and welder

qualification records to confirm that the Code-required essential and supplemental

essential welding variables were met. The inspectors reviewed the WO packages, including welding electrode receipt inspection, vacuum box leak testing, MT records, material certification records, and qualification and certification records for NDE

personnel, equipment, and consumables.

Heavy Load, Rigging, Lifting, and Transporting Activities The inspectors reviewed the SG lifting preparation activities and lifting equipment load

test data to ensure that they were prepared in accordance with regulatory requirements, appropriate industrial codes and standards, and to verify that the maximum anticipated loads to be lifted would not exceed the capacity of the lifting equipment and supporting structures. The inspectors reviewed procedures, calculations, drawings, work packages, crane and equipment operator training and certificates, and load and function test

records to verify that they were in accordance with regulatory requirements and

appropriate industrial codes and standards. The inspectors also examined SGRP lifting, rigging, and transporting equipment, including the polar crane, mobile crane, the

Temporary Lifting Device (TLD), the Horizontal Transfer System (HTS) (including its skid

system), the down/upender device, the Outside Lift System (OLS), and the self-propelled modular transporter (SPMT). The inspectors observed a selective sampling of rigging, lifting, transportation, and positioning of the original and replacement SGs.

Quality Assurance (QA) Program and Corrective Actions The inspectors conducted a review of the quality assurance program and its

implementation for the SG replacement to assess compliance with the requirements of

10 CFR Part 50, Appendix B. The inspectors also reviewed the surveillance reports and

nonconformance reports issued for the root cause analyses, evaluations, repairs, or

disposition during the manufacturing of the RSGs.

SG Post-Installation Verification and Testing The inspectors reviewed the SG post-installation verification and testing program to

verify that the required post-installation verification and testing, procedural changes, and

the adjustment of the instruments were properly identified.

Containment Detensioning The inspectors conducted a review of the licensee's detensioning activities for the repair

of the delaminated containment wall and restoration of the containment wall to it

pre-construction opening condition, including associated ECs and Work Packages (WPs). The inspectors also observed vertical and horizontal tendon detensioning. The

inspectors observed and reviewed the records of the acoustic monitors and strain

gauges used to detect sound volumes and concrete strain changes potentially due to

new cracks or compressive or tensile stress changes in the concrete during the

detensioning process. The inspectors reviewed the procedures, drawings, calibrations, equipment and personnel qualifications, and the tendon detensioning communication

plan associated with detensioning to verify that the licensee performed the activities in

accordance with approved procedures.

Concrete Removal, Surface Preparation, and Concrete Placement Activities The inspectors conducted a review of the licensee's activities associated with the

removal of the damaged concrete and restoration of the containment wall. The

inspectors reviewed associated documents, including ECs, WPs, specifications, drawings, test reports, and NCRs. The inspectors observed the process of the

hydro-demolition of damaged concrete, the surface preparation of concrete after the

hydro-demolition, and pull-out testing to assure that the concrete surface would have

enough tensile strength to bond the new and original concrete. The inspectors reviewed

radial rebar drilling; grouting; and identified void problems, and their respective

resolutions. The inspectors observed rebar and formwork installation and tendon sleeve

condition in preparation of the concrete pour. The inspectors also reviewed the

associated engineering packages, WPs, and drawings to verify that licensee activities were performed in accordance with approved documents. The inspectors observed concrete placement activities to verify that activities pertaining to concrete delivery time, flow distance, layer thickness, etc. conformed to industry standards established by the

American Concrete Institute (ACI). The inspectors also observed that concrete

placement activities were monitored by the licensee and contractor's quality control

personnel and engineers. The inspectors observed in-process concrete testing and

reviewed the results for slump, air content, temperature, and unit weight, to verify that

this was done in accordance with applicable American Society for Testing and Materials (ASTM) requirements. The inspectors checked the batch plant for its certification and

reviewed its preparation for the concrete pour. During the concrete placement activities, the inspectors identified a finding of very low safety significance and an associated non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion IX, "Control of Special

Processes," for the licensee's failure to establish measures to assure that testing of

rebar splices would adhere to the requirements of ASME Boiler and Pressure Vessel

Code. (Refer to Section 4OA5.3 of Inspection Report 05000302/2010004 (ML103020127) for additional details about NCV 05000302/2010004-03, Failure to

Submit Production Splices of Swaged Mechanical Splices for Testing.)

Containment Dome Cracks On April 14, 1976, a delamination was identified in the containment dome during the final

stages of containment construction and before initial plant startup. The area of the

delaminated concrete was approximately circular in shape with a 105-foot diameter. The

dome repair process included removal of the delaminated dome cap; removal of

meridional, hoop, and radial reinforcement; and placement of a new dome cap.

Instrumentation was installed to monitor the dome during tendon detensioning, retensioning and the initial structural integrity. As part of the Special Inspection to

assess the circumstances associated with the delamination discovered in 2009, NRC

inspectors conducted a review of the licensee's conclusion that the delamination

identified in 1976 is not related to the current delamination. Additional background

information and the results of these inspections are presented in NRC Inspection Report 05000302/2009007 (ML1028610261).

In 2009, NRC Special Inspection Team inspectors conducted concrete surface

inspections on the containment dome and identified a rough and uneven surface

condition of the dome surface. The inspectors reviewed the evaluation and corrective

action that determined the rough and uneven surface condition of the dome has existed

since the 1976 repair. The licensee had periodically completed numerous surface

patches in an attempt to address the surface spalls. Following additional reviews of the

dome tendon stresses and monitoring, the uneven surface also appeared to be a result

of concrete installation and finishing from the 1976 repair and not related to settlement of

the dome or the 2009 containment concrete wall delamination issue.

In 2010, the inspectors reviewed a condition assessment of the containment dome

documented in the licensee's engineering change package EC 74801. The licensee had

included this assessment in the activities associated with its 2009 containment extent-of-

condition investigation. Included was Impulse Response (IR) testing and core bores

made in support of evaluating the IR data. Anomalies were identified and, to evaluate

the anomalies, additional examinations were performed. A total of about 10,000 points

were tested and a total of 30 core samples were removed. Visual inspections were

performed of each core sample and a video scope inspection of each core hole was

performed after the core sample was removed. This evaluation revealed cracking in the plane of the dome (laminar cracking). The licensee determined that these anomalies were remnants of the repairs performed in 1976.

The inspectors reviewed the CTLGroup Project No. 059176 - Dome Report, which

included the results of the examinations identified above. The information contained in

this report was subsequently utilized in an engineering evaluation documented in

Containment Dome Evaluation, Report No. CR-3-LI-537934-52-SE-0059. The

engineering evaluation determined that the repairs made to the dome structure in 1976

are intact; that there are no significant anomalies, discrepancies, or structural issues

which would affect the overall structural integrity of the dome structure; and that the

structure is capable of performing its design basis functions as described in the Updated

Final Safety Analysis Report (UFSAR).

Additional information is presented in NRC Inspection Report 05000302/2009007 (ML1028610261).

Containment Tendon Retensioning Plan The inspectors reviewed the containment tendon retensioning plan, testing plan, and

schedule. The inspectors also interviewed licensee personnel and reviewed documents

related to the retensioning and testing plans. The licensee conducted a detailed

analysis to develop a tendon retensioning sequence that would minimize the possibility of causing new cracks or delaminations in the containment during the retensioning

process. The retensioning process began in January 2011. The inspectors also

reviewed licensee plans for Containment Building testing after completion of tendon

retensioning and post-maintenance testing after restart.

.2 SGRP Inspection Activities January 1, 2011 through April 22, 2011

Discussion of Technical Issues The following issues were discussed with licensee personnel during this inspection

period: Bulges of Liner Plate The inspectors completed a review of the licensee's actions related to containment liner

bulges. The licensee developed a calculation to evaluate bulges in the CR3

containment liner plate. It was directed at determining an apparent cause for the bulges

and establishing an analytically-based acceptance criterion for the bulges within the CR3

design basis. The analyses included finite element modeling of the liner and the

associated anchorage to the concrete containment structure. The apparent cause for

the bulges was determined to be a combination of elements, including geometrical

imperfections in the original liner plate during construction. The calculations considered

worst case configurations and a threshold for bulge size was established considering the

effects that occur due to normal operation and accident conditions. The primary

variables in the bulge evaluation were determined to be bulge size and thermal loading.

The calculation found that the bulges have an insignificant effect on the response of the

structure due to various load combinations. The current bulges are bounded by the

acceptance criteria in the analysis. To ensure that conditions are acceptable in the

future, the licensee planned to include the bulges in the IWE program. The licensee

added a summary evaluation to the EC, which includes steps to validate the effect of retensioning on bulge size by measurement and evaluation of a representative sample before initiating Structural Integrity Test (SIT) pressurization as well as requirements to

perform a complete baseline scan after completion of the SIT.

50.59 Evaluation The inspectors reviewed the licensee's evaluation of the containment building

modification resulting from the introduction of the construction opening and its

subsequent restoration with respect to requirements of 10 CFR, § 50.59, Changes, Tests and Experiments, to verify that the design bases, licensing bases, and

performance capability of the containment had not been degraded through the

modification and to verify that the design and license basis documentation used to

support changes reflect the design and license basis of the facility after the change had

been made.

The inspectors' review remained ongoing at the end of the inspection period. Remaining

activities necessary to complete the 50.59 review included: verification that tendon

retensioning activities and containment testing validated licensee design assumptions;

verifying that post-modification testing adequately confirmed containment functionality

via the scheduled Structural Integrity Test (SIT) and Integrated Leak Rate Test (ILRT)

prior to unit startup; verifying that design basis documentation used to support changes

and design basis documentation affected by changes had been adequately updated and

reflected the modified design and license basis of the facility consistent with the

restoration; and verifying that the license's UFSAR had been updated accordingly.

Vertical Cracks of Containment Building One of the licensee's design assumptions for containment repair was that vertical cracks discovered on the exterior wall of the containment building would close as the building's tendons were retensioned. The inspectors walked down selected vertical cracks being monitored by the licensee to evaluate their condition. The licensee had measured the cracks periodically and determined that they were closing as the tendon retensioning process continued. The inspectors also visited the tendon control center where the retensioning process was controlled, and which housed the acoustic monitoring and strain gage instrumentation, and interviewed personnel in the center to better understand the operation of the systems being used and how the information obtained was interpreted.

The inspectors' review of vertical cracks remained ongoing pending inspection of the containment building after all repairs are completed and tendons are fully retensioned, and the completion of the SIT and ILRT.

Tendon Re-tensioning Activities The inspectors reviewed the licensee's re-tensioning plans, procedures, and drawings.

In addition the inspectors observed some of the re-tensioning work being performed on

selected hoop tendons to verify that the work was being conducted per approved

procedures.

SIT/ILRT Preparations The inspectors interviewed licensee personnel responsible for the planned SIT/ILRT to

determine the status of the test preparations; walked down the containment building to

verify the locations of the extensometers to be used to measure the containment

movements during the SIT/ILRT; and discussed the licensee's procedures to ensure that

they conformed to industry standards and ASME Code requirements.

Events of March 14, 2011 On the afternoon of March 14, 2011, the licensee had completed the first retensioning

sequence (Sequence #100, Hoop Tendons 42H41, 62H41, and 64H41) of the final pass (Pass #11). Per procedure, the licensee was waiting for the containment building to

stabilize before beginning the next sequence and monitoring the structural behavior of

the containment building via acoustical emissions monitors and strain gauges, specifically placed at various points of the structure to detect any abnormal/unexpected

response to tendon retensioning. During this monitoring period, the strain gauges

indicated an increase in strain and then failed high, and the acoustic monitors indicated

a high level of acoustic activity in the bay bordered by Butresses #5 and #6 (Bay 5-6).

The phenomenon reportedly lasted for about twenty minutes. The licensee conducted

impulse response (IR) non-destructive examination NDE techniques to determine the

condition of the wall in Bay 5-6. The IR scans of the bay determined that there were

numerous indications consistent with a delamination. By the end of the inspection

period, the licensee had determined that the delamination was extensive in Bay 5-6 and

was continuing to evaluate the condition of the entire containment structure. Future

inspection activities by the NRC relating to the March 14, 2011, event are to be

determined.

4OA6 Meetings, Including Exit

Exit Meeting Summary

On April 28, 2011, the inspectors presented the inspection results to Mr. J. Franke, Site

Vice President, and other members of licensee management via a telephone call. The

inspectors confirmed that proprietary info rmation was not provided or examined during the inspection.

ATTACHMENT:

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Licensee personnel

S. Cahill, Manager, Engineering

P. Dixon, Progress Energy

P. Fagan, RNP Technical Services Superintendent

G. Flavors, Nuclear Upgrades

J. Franke, Site Vice-President

T. Howard, Engineering

J. Holt, Site General Manager

J. Huegel, Nuclear Oversight

R. Knott, NPC Lead Engineer

M. Rigsby, Manager - Support Services

NRC personnel

D. Rich, Chief, Branch 3, Division of Reactor Projects

T. Morrissey, Senior Resident Inspector

R. Reyes, Resident Inspector

LIST OF ITEMS

Opened

None.

Closed

None.

Discussed

05000302/2010004-03 NCV Failure to Submit Production Splices of

Swaged Mechanical Splices for Testing