Information Notice 2008-17, Construction Experience with Concrete Placement Process
| ML081850581 | |
| Person / Time | |
|---|---|
| Issue date: | 10/22/2008 |
| From: | Michael Case, Dan Dorman, Tracy G NRC/NMSS/FCSS, Office of New Reactors, Division of Policy and Rulemaking |
| To: | |
| References | |
| IN-08-017 | |
| Download: ML081850581 (5) | |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
OFFICE OF NEW REACTORS
WASHINGTON, DC 20555-0001 October 22, 2008 NRC INFORMATION NOTICE 2008-17: CONSTRUCTION EXPERIENCE WITH
CONCRETE PLACEMENT
ADDRESSEES
All current and potential applicants for an early site permit, combined license, or standard
design certification for a nuclear power plant under the provisions of Title 10 of the Code of
Federal Regulations (10 CFR) Part 52, Licenses, Certifications, and Approvals for Nuclear
Power Plants, all current holders of and potential applicants for construction permits under
10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities, and all licensees
and potential applicants for new fuel cycle facilities under 10 CFR Part 70, Domestic Licensing
PURPOSE
The United States (U.S.) Nuclear Regulatory Commission (NRC) is issuing this information
notice (IN) to alert addressees to the importance of considering lessons learned from
construction experience when planning for and constructing new nuclear power plants or fuel
cycle facilities. Recipients are expected to review the information for applicability to their
planned activities and consider actions to avoid similar problems. The suggestions contained in
this IN are not NRC requirements, and no specific action or written response is required.
BACKGROUND
The nuclear industry in the U.S. faced many construction quality and design issues in the 1970s
and 1980s. In 1984, the NRC issued NUREG-1055, Improving Quality and the Assurance of
Quality in the Design and Construction of Nuclear Power Plants, to document the lessons
learned from plant construction in the U.S. (Agencywide Documents Access and Management
System (ADAMS) Accession No. ML063000293). The NRC also issued IN 2007-04, Construction Experience Related to the Assurance of Quality in the Construction of Nuclear
Facilities (ADAMS Accession No. ML063040426), to alert addressees to the importance of
considering lessons learned from construction experience when planning for and constructing
new nuclear power plants or fuel cycle facilities.
Recently identified problems in some domestic and international construction projects could
provide new insights to the nuclear industry to understand the causal factors and to avoid
similar mistakes in the future. The experiences referenced in this IN mainly focus on problems
with concrete placement processes in the construction of new nuclear power plants and a fuel
fabrication facility. The NRC believes this information is appropriate for consideration in the
construction of any nuclear facilities.
DESCRIPTION OF CIRCUMSTANCES
Concrete Placement Issues at Olkiluoto 3 in Finland
An investigation report, issued July 10, 2006, on the construction problems and resulting delays
of Olkiluoto 3 by the Finnish Radiation and Nuclear Safety Authority (STUK), identified several
contributing factors. Among them was the concrete placement of the reactor building basemat.
During this phase of construction, Teollisuuden Voima Oy (TVO), the licensee, detected
inconsistencies in the concrete between different truckloads. TVO confirmed that the plasticizer
caused the variation. Other problems involved water-cement ratios outside of design
requirements and changes in the composition of the concrete made by the contractor outside of
the procedural process without the licensees knowledge. As a result, the licensee and
regulator required various tests on the concrete and also investigated the construction site
operations. Test results indicated that the concrete met minimum standards. Investigation of
site operations indicated that this event was, in part, caused by the lack of communication, the
lack of defined responsibilities, and poor quality control. Although the concrete was ultimately
found acceptable, this event caused lengthy construction delays and had a negative impact on
public confidence. The full STUK investigation report is available online at
http://www.stuk.fi/stuk/tiedotteet/2006/en_GB/news_419/_files/76545710906084186/default/inve
stigation_report.pdf
Concrete Mixing Issues at Mixed Oxide Fuel Fabrication Facility
In September 2007, an NRC inspector at the Mixed Oxide (MOX) Fuel Fabrication Facility
(MFFF) construction site observed various problems with concrete placement. Based on the
applicants rejection of five concrete truckloads due to concrete slumps being outside of the
design value, the inspector performed an inspection of the concrete batch plant. During
inspection at the batch plant, which was operated by a contractor, the inspector noted that
chemical plasticizer and water that exceeded the manufacturers recommendation and the
design specification were added to the design mix. The addition was made without procedural
guidance and was not documented. In response to the NRC inspection, the applicant, Shaw
AREVA MOX Services, assumed responsibility for concrete testing at the batch plant, provided
immediate quality assurance coverage of all batching operations, ensured that batch plant
procedures were written or revised as necessary, and consulted independent experts for
recommendations for improvement. NRC Team Inspection Report 70-3098/2007-004 is
available as a public document in ADAMS under Accession No. ML073030407.
In January 2008, at the construction site of the MFFF, a concrete reinforcement steel bar failed.
The reinforcement steel bar fractured near a bend location due to work hardening during the
bending process. In response, the NRC conducted a reactive inspection in February 2008, which revealed problems with bent rebar, primarily in the foundation of the facility. This led to
NRC inspections of the reinforcing steel vendor and the MFFF site. The inspection of the steel
vendor revealed the following five nonconformances: inadequate surveillance of the fabrication
of rebar, inadequate audits of sub-suppliers, failure to verify adequacy of design in the
dedication of commercial grade items, failure to write a corrective action process condition
report for a significant condition adverse to quality, and the failure to properly disposition a code
deficiency. The MFFF inspection yielded no findings. The applicant had already issued more
than 80 condition reports addressing problems with vendor parts and further increased oversight of vendor activities. NRC Team Inspection Reports 70-3098/2008-005 and 99900866/2008-001 are available as public documents under ADAMS Accession Nos. ML081340672 and
ML081410040. Additionally, NRC Inspection Report 07003098/2007-003 (ADAMS Accession
No. ML072080093), provides information on nonconformance reports issued by the licensee to
the steel vendor.
Concrete Placement Issues at Flamanville 3 in France
An inspection of the Electricite de France (EDF) Flamanville 3 European Pressurized Reactor
construction site by the Autorite de Surete Nucleaire (ASN) in March 2008 revealed several
problems with the reinforcement steel bars and concrete placement for the basemat of the fuel
storage buildings. The inspection revealed improperly spliced and tied rebar, and reinforcing
steel placement that did not conform to approved procedures and design requirements. Despite
these deficiencies, the concrete contractor had initiated the concrete placement procedure.
ASN was able to check that corrective action had been taken accordingly before concrete had
actually been placed in the area. In another case, the concrete reinforcement and placement
did not follow the construction specifications and drawings. A review of site conformance
records indicated that some aspects of the work were flagged with specific notations as
potential nonconformances, but the follow-up actions were not tracked. Accordingly, ASN
requested that the licensee provide additional information. For the issue of improperly spliced
and tied rebar and nonconforming reinforcing steel placement, assurances that prior concrete
placements were free of inconsistencies with the design requirements were requested. In the
case where implementation did not match the construction specifications and drawings, ASN
requested that the licensee document and validate the alternate methods, and explain the
reasons for the failure to follow approved construction procedures. ASN requested information
about the causes leading to the failure to track and close deficiencies identified in field records.
The letter from ASN to the licensee (in French) detailing the inspection findings and required
actions can be found online at http://www.asn.fr/sections/rubriquesprincipales/actualites/lettre- suite-d/genie-civil_10/downloadFile/file/INS_2008_EDFFA3_0012.pdf
On May 21, 2008, EDF informed ASN about another nonconformity concerning the
reinforcement steel of the basemat of the safeguard auxiliary buildings, specifically, a lack of
stirrups. Beyond the technical nonconformance, ASN considers the main issue to be the
licensees quality management system. A preliminary analysis of the root causes indicated that
the nonconformance had not been corrected before concrete placement although the lack of
stirrups had been identified on time by both the subcontractors and the licensee. Consequently, ASN stopped the concrete placement activities of all buildings relevant to safety, mainly the
pumping station and nuclear island basemat. ASN asked the licensee to provide detailed plans
to identify managerial and organizational enhancements to support improved oversight of field
activities, and to facilitate field task tracking. The licensee submitted its revised action plan, and
ASN determined that it would allow the proposed improvement to the quality management
system of Flamanville 3. On June 17, 2008, ASN authorized the licensee to resume concrete
placement activities on all buildings except the basemat of the safeguard auxiliary buildings.
For the safeguard auxiliary buildings, the licensee submitted a technical analysis of the
nonconformance and a proposed correction that have been assessed by ASN. ASN then
authorized the licensee to resume concrete placement activities on the safeguard auxiliary
buildings in July 2008.
DISCUSSION
Both abroad and in the U.S., interest in new reactor and fuel cycle facility construction is
resuming after many years. However, problems in nuclear construction, similar to those
identified in the U.S. more than 20 years ago, have resurfaced. Although the technical issues
vary, inspections repeatedly identify a lack of contractor oversight and poor quality control in
concrete placement. A commitment to quality, applied early in a construction project, ensures
that a facility is constructed and operated in conformance with its license and NRC regulations.
Particular attention should be given to quality assurance program effectiveness and the
implementation of 10 CFR 50, Appendix B requirements, especially when the construction work
is directly related to nuclear safety and is performed by contractors. Also, concrete placement
problems can be avoided by ensuring the correct installation of the rebar in accordance with the
approved drawing details and complying with the applicable American Concrete Institute codes.
Specifically, prevention of problems similar to those identified necessitates appropriate controls
in activities such as: (1) concrete batch plant inspections and truck mixer quality checks (e.g.,
slump tests), (2) rebar bending, (3) concrete placement and consolidation using vibrators, (4)
quality control checks of the rebar installation (prior to concrete placement), and the visual
inspection of the concrete placement activities, and (5) concrete testing (e.g., cylinder samples
and compressive strength breaks).
CONTACT
This information notice requires no specific action or written response. Please direct any
questions about this matter to the technical contact listed below.
/RA/ /RA/
Michael Case, Director Glenn Tracy, Director
Division of Policy and Rulemaking Division of Construction Inspection and
Office of Nuclear Reactor Regulation Operational Programs
Office of New Reactors
/RA/
Daniel Dorman, Director
Division of Fuel Cycle Safety and Safeguards
Office of Nuclear Materials Safety and Safeguards
Technical Contacts: Richard Laura Omid Tabatabai
NRO/DCIP/CCIB NRO/DCIP/CCIB
(301) 415-1837 (301) 415-6616 richard.laura@nrc.gov omid.tabatabai@nrc.gov
Principal Contributor: Genevieve Russo
NRO College Intern
Massachusetts Institute of Technology
Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections
DISCUSSION
Both abroad and in the U.S., interest in new reactor and fuel cycle facility construction is resuming after
many years. However, problems in nuclear construction, similar to those identified in the U.S. more than
20 years ago, have resurfaced. Although the technical issues vary, inspections repeatedly identify a lack
of contractor oversight and poor quality control in concrete placement. A commitment to quality, applied
early in a construction project, ensures that a facility is constructed and operated in conformance with its
license and NRC regulations. Particular attention should be given to quality assurance program
effectiveness and the implementation of 10 CFR 50, Appendix B requirements, especially when the
construction work is directly related to nuclear safety and is performed by contractors. Also, concrete
placement problems can be avoided by ensuring the correct installation of the rebar in accordance with
the approved drawing details and complying with the applicable American Concrete Institute codes.
Specifically, prevention of problems similar to those identified necessitates appropriate controls in
activities such as: (1) concrete batch plant inspections and truck mixer quality checks (e.g., slump tests),
(2) rebar bending, (3) concrete placement and consolidation using vibrators, (4) quality control checks of
the rebar installation (prior to concrete placement), and the visual inspection of the concrete placement
activities, and (5) concrete testing (e.g., cylinder samples and compressive strength breaks).
CONTACT
This information notice requires no specific action or written response. Please direct any questions about
this matter to the technical contact listed below.
/RA/ /RA/
Michael Case, Director Glenn Tracy, Director
Division of Policy and Rulemaking Division of Construction Inspection and
Office of Nuclear Reactor Regulation Operational Programs
Office of New Reactors
/RA/
Daniel Dorman, Director
Division of Fuel Cycle Safety and Safeguards
Office of Nuclear Materials Safety and Safeguards
Technical Contacts: Richard Laura Omid Tabatabai
NRO/DCIP/CCIB NRO/DCIP/CCIB
(301) 415-1837 (301) 415-6616 richard.laura@nrc.gov omid.tabatabai@nrc.gov
Principal Contributor: Genevieve Russo
NRO College Intern
Massachusetts Institute of Technology
Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections
DISTRIBUTION:
IN File
ADAMS ACCESSION: ML081850581 OFFICE CCIB:DCIP:NRO Tech Ed. TL:CCIB:DCIP:NRO BC:CCIB:DCIP:NRO BC:IAC:OIP BC:MB:FCSS:NMSS OGC (NLO)
NAME GRusso HChang RLaura RRasmussen CAbrams MKotzalaz MSpencer
DATE 07/15 /08 07/18 /08 08/18 /08 08/18 /08 10/15/2008 10/10/2008 08/22/08 OFFICE LA:PGCB:NRR PM:PGCB:NRR BC:PGCB:NRR D:DCIP:NRO D:FCSS:NMSS D:DPR:NRR
NAME CHawes DBeaulieu MMurphy GTracy DDorman MCase
DATE 09/17/08 10/03/08 10/22/08 09/12/08 10/21/2008 10/22/08 OFFICIAL RECORD COPY