ML090830184

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 selfundercutting anchors had loosened from their positions on two feedwater system pipe supports. 

These supports were recently installed as part of an upgrade program. 
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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 utility’s 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 NRC’s 

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. 
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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 plant’s system design and construction departments. 
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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 

 Alexander Tsirigotis, NRR 

 (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.
IN 2010-01 

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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 

 Alexander Tsirigotis, NRR 

 (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 

OFFICIAL RECORD COPY