Information Notice 2010-01, Pipe Support Anchors Installed Improperly
| ML090830184 | |
| Person / Time | |
|---|---|
| Issue date: | 03/01/2010 |
| From: | Dan Dorman, Mcginty T, Tracy G NRC/NMSS/FCSS, Division of Construction Inspection and Operational Programs, NRC/NRO/DCIP/CCIB, Division of Policy and Rulemaking |
| To: | |
| Gaslevic, J.,NRO/DCIP/CCIB, 415-2776 | |
| References | |
| IN-10-001 | |
| Download: ML090830184 (5) | |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
OFFICE OF NEW REACTORS
WASHINGTON, DC 20555-0001 March 1, 2010
NRC INFORMATION NOTICE 2010-01: PIPE SUPPORT ANCHORS INSTALLED
IMPROPERLY
ADDRESSEES
All holders of an operating license or construction permit for a nuclear power reactor issued
under Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of
Production and Utilization Facilities, except those who have permanently ceased operations
and have certified that fuel has been permanently removed from the reactor vessel.
All holders of or applicants for an early site permit, standard design certification, standard
design approval, manufacturing license, or combined license issued under 10 CFR Part 52, Licenses, Certifications, and Approvals for Nuclear Power Plants.
All holders of or applicants for a license for a fuel cycle facility issued pursuant to
10 CFR Part 70, Domestic Licensing of Special Nuclear Material.
All holders of or applicants for a certificate of compliance issued under 10 CFR Part 76, Certification of Gaseous Diffusion Plants.
PURPOSE
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to alert
addressees of recent construction-related issues involving improperly installed pipe support
anchors at several German nuclear power plants. Recipients should review the information for
applicability to their facilities 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.
DESCRIPTION OF CIRCUMSTANCES
Improper Assembly of Pipe Support Undercut Anchors at Biblis, Unit A, in Germany
During a plant shutdown in September 2006 at Biblis Unit A, a four-loop pressurized-water
reactor located in South Hessian, Germany, a walkdown revealed that some Hilti HDA-T self- undercutting anchors had loosened from their positions on two feedwater system pipe supports.
These supports were recently installed as part of an upgrade program.
Inspections of other upgraded anchors of the same type revealed some additional improperly
installed anchors. The Hilti HDA-T was the only anchor design with this problem. Examination
revealed that bore holes for the affected anchors were either drilled too deep or not deep
enough because the utility staff did not use bits that limit drilling depth. As a result, the anchors
could not undercut properly. In places where bore holes were drilled to the correct depth, the
expander sleeves were not driven in deep enough. Further investigations revealed that in some
instances too few anchors were installed, anchors were installed in the wrong position, missing
washers were identified, wrong anchor types were used, and misdrilled holes were not plugged
properly. Of the approximately 15,000 Hilti HDA-T anchors installed in the two Biblis units since
2001, about 7,500 needed repair.
Insufficient oversight and training, improper tools, lack of detailed checklists, insufficient written
instructions, inadequate supervision during construction, lack of inspection after work was
completed, and inadequate quality assurance controls and quality control measures contributed
to the utilitys failure to achieve early detection and correction of these defects.
Other German plants inspected their safety relevant anchors after the problem was discovered.
Similar problems were found at Gundremmingen, Kruemmel, Brunsbuettel, Grohnde, Emsland, and Munich FRM-II research power plants. Hilti, Fischer, Paslode, TiFix, and Liebig
manufactured the affected anchors. The improperly installed anchors were undercut anchors, self-undercut anchors, and expansion anchors.
BACKGROUND
The following NRC communications related to this issue include:
- NUREG-1055, Improving Quality and the Assurance of Quality in the Design and
Construction of Nuclear Power Plants, issued May 1984, can be found on the NRCs
public website in the Agency Documents Access and Management System (ADAMS)
under Accession No. ML063000293.
- IN 2007-04, Construction Experience Related to the Assurance of Quality in the
Construction of Nuclear Facilities, dated February 7, 2007, ADAMS Accession
No. ML063040426.
- Regulatory Guide 1.199, Anchoring Components and Structural Supports in Concrete, issued November 2003, ADAMS Accession No. ML033360660.
- Inspection and Enforcement Bulletin 79-02, Pipe Support Base Plate Designs Using
Concrete Expansion Anchor Bolts, originally dated March 8, 1979, and revised
June 21, 1979, and November 8, 1979; ADAMS Accession Nos. ML031210357, ML031210363, and ML031210461, respectively.
DISCUSSION
Hangers, supports, pipe anchors, and restraints are selected to withstand all static and dynamic
loading conditions that act upon the piping system and associated equipment. They should be
considered as a total system, since failure of some supports could redistribute the loads to other
supports. Pipe supports control the effects of accident-related forces and displacement, seismic-induced displacement, and vibrations. Improperly installed pipe supports and anchors
can adversely affect the analyzed stresses of connected piping systems, which can lead to
piping failure and render the affected systems inoperable. Properly installed undercut anchors
are necessary to develop the anchor-bolt rated allowable loads. The risk significance of multiple
improper anchor installations is increased by a potential common-mode failure of other piping.
This IN stresses the importance of following anchor installation procedures and illustrates some
of the consequences of departure from the required procedures. Appendix B, Quality
Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants, to 10 CFR Part 50
establishes quality assurance requirements for safety-related equipment at U.S. nuclear power
plants. Adequate quality assurance and quality control measures provide for the early detection
and correction of such defects.
The affected utilities have since improved personnel training, post-installation checks, and
cooperation between the plants system design and construction departments.
CONTACT
This IN requires no specific action or written response. Please direct any questions about this
matter to the technical contacts listed below.
/RA/ /RA/
Timothy McGinty, Director Glenn Tracy, Director
Division of Policy and Rulemaking Division of Construction Inspection
Office of Nuclear Reactor Regulation & Operational Programs
Office of New Reactors
/RA/
Daniel H. Dorman, Director
Division of Fuel Cycle Safety and Safeguards
Office of Nuclear Material Safety and Safeguards
Technical Contacts: Omid Tabatabai, NRO Mahmoud Jardaneh, NRO
(301) 415-6616 (301) 415-2753 Omid.Tabatabai@nrc.gov Mahmoud.Jardaneh@nrc.gov
(301) 415-2258 Alexander.Tsirigotis@nrc.gov
Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections.
CONTACT
This IN requires no specific action or written response. Please direct any questions about this
matter to the technical contacts listed below.
/RA/ /RA/
Timothy McGinty, Director Glenn Tracy, Director
Division of Policy and Rulemaking Division of Construction Inspection
Office of Nuclear Reactor Regulation & Operational Programs
Office of New Reactors
/RA/
Daniel H. Dorman, Director
Division of Fuel Cycle Safety and Safeguards
Office of Nuclear Material Safety and Safeguards
Technical Contacts: Omid Tabatabai, NRO Mahmoud Jardaneh, NRO
(301) 415-6616 (301) 415-2753 Omid.Tabatabai@nrc.gov Mahmoud.Jardaneh@nrc.gov
(301) 415-2258 Alexander.Tsirigotis@nrc.gov
Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections.
ADAMS ACCESSION: ML090830184 ME0880 NRR-052 OFFICE CTSB:DCIP:NRO CCIB:DCIP:NRO Tech Ed. TL:CCIB:NRO BC:CCIB:NRO
NAME MJardaneh JGaslevic KAzariah-Kribb OTabatabai JStarefos
DATE 8/24/09 3/25/09 9/25/09 (via email) 4/2/09 4/20/09 OFFICE BC:OIP OGC (NLO) EMCB:NRR BC:EMCB:NRR PGCB:DPR
NAME CAbrams (BWittick for) SPrice ATsirigotis MKhanna DBeaulieu
DATE 8/26/09 9/24/09 12/4/09 12/4/09 (via email) 1/6/10
OFFICE PGCB:DPR BC:PGCB:DPR D:FCSS:NMSS D:DCIP:NRO D:DPR
NAME CHawes MMurphy DDorman GTracy TMcGinty
DATE 1/7/10 1/19/10 2/26/10 2/16/10 3/01/10
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