Information Notice 2010-14, Containment Concrete Surface Condition Examination Frequency and Acceptance Criteria
| ML101600151 | |
| Person / Time | |
|---|---|
| Issue date: | 08/04/2010 |
| From: | Mcginty T, Tracy G Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| IN-10-014 | |
| Download: ML101600151 (5) | |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
OFFICE OF NEW REACTORS
WASHINGTON, DC 20555-0001 August 4, 2010
NRC INFORMATION NOTICE 2010-14: CONTAINMENT CONCRETE SURFACE
CONDITION EXAMINATION FREQUENCY AND
ACCEPTANCE CRITERIA
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 standard design certification, standard design approval, or
combined license issued under 10 CFR Part 52, Licenses, Certifications, and Approvals for
Nuclear Power Plants.
PURPOSE
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to inform
addressees of recent issues identified by the NRC staff during license renewal application (LRA)
review audits at different nuclear power plant sites concerning the containment concrete surface
condition examination frequency and acceptance criteria. The NRC expects recipients to review
the information for applicability to their facilities and consider actions, as appropriate, to avoid
similar problems. The suggestions that appear in this IN are not NRC requirements; therefore, no specific action or written response is required.
DESCRIPTION OF CIRCUMSTANCES
During recent LRA audits, the NRC staff found that some nuclear plant licensees did not meet
the requirements for containment concrete surface examinations specified in 10 CFR 50.55a, Codes and Standards, dated August 8, 1996, and in Article IWL-2510, Surface Examination, of Subsection IWL, Requirements for Class CC Concrete Components of Light-Water-Cooled
Power Plants, of Section XI, Rules for Inservice Inspection of Nuclear Power Plant
Components, of the American Society of Mechanical Engineers (ASME) Boiler and Pressure
Vessel Code. Specifically, 10 CFR 50.55a incorporates, by reference, Subsection IWL, which
requires periodic inservice inspections (ISIs) of containment concrete. Paragraph IWL-2410(a),
as modified by 10 CFR 50.55a(g)(6)(ii)(B)(2) based on the final rulemaking of August 8, 1996, states, Concrete shall be examined in accordance with IWL-2510[at all operating nuclear
power plants by September 9, 2001] and every 5 years thereafter. However, during recent
LRA audits of some multiple-unit nuclear power plants, the NRC staff found that some licensees
of pressurized-water reactor (PWR) plants have been performing the containment concrete
condition surface examination every 10 years.
The NRC staff also found that the containment concrete surface degradation quantitative
acceptance criteria used by the licensees for the ASME Section XI, Subsection IWL, aging
management program (AMP) were significantly less stringent than the acceptance criteria
specified in American Concrete Institute (ACI) 201.1, Guide for Making a Condition Survey of
Concrete in Service, and ACI 349.3R, Evaluation of Existing Nuclear Safety-Related Concrete
Structures. Article IWL-2510 recommends the use of ACI 201.1 and ACI 349.3R guidelines in
developing site-specific inspection programs.
According to ACI 349.3R, concrete surfaces that are exposed and accessible for inspection and
that have popouts and voids that are more than 2 inches, scaling of more than 0.75 inch in
depth and 8 inches in diameter, and cracks larger than 0.04 inch in width are considered
unacceptable and in need of further technical evaluation. However, during the LRA audit at
some PWR plants, the NRC staff noted that the licensees inspection criteria allow popouts of
up to 4 inches, scaling of 3 inches in depth and 8 feet in diameter, and cracks of 0.4 inch in
width without further technical evaluation or repair.
BACKGROUND
NUREG-1801, Generic Aging Lessons Learned (GALL) Report, Revision 1, Volume 2, Tabulation of Results, issued September 2005, states that the evaluation of concrete
containment in accordance with 10 CFR 50.55a and Subsection IWL is part of an AMP for
license renewal. AMP XI.S2, ASME Section XI, Subsection IWL, in the GALL Report states
that Article IWL-2400 specifies the frequency of concrete inspection. In addition, AMP XI.S2 states that concrete acceptance criteria are qualitative and that guidance is provided in
Article IWL-2510, which references ACI 201.1 for the identification of concrete degradation.
Quantitative acceptance criteria based on the evaluation criteria provided in Chapter 5 of
ACI 349.3R should also be used to augment the qualitative assessment of the responsible
engineer.
DISCUSSION
Concrete containments are required to be operable as specified in plant technical specifications
to limit the leakage of fission product radioactivity from the containment to the environment and
to resist design-basis loads such as seismic and internal pressure during an accident. The
regulations at 10 CFR 50.55a and their modifications and limitations mandate the use of
Subsection IWL to perform ISIs for reinforced and prestressed concrete containments (Class
CC). The primary inspection method specified in Subsection IWL for concrete surface
examination is visual examination.
The ISI plan established by licensees at some multiple-unit PWR sites specifies a concrete
containment visual examination frequency of 10 years, which is two times the frequency (5 years) specified in Article IWL-2410 of Subsection IWL. This increase in ISI duration extends
the period that concrete and steel reinforcement degradation can go undetected, allowing
further progression until the degradation is corrected. In addition, licensees use of concrete surface degradation quantitative acceptance criteria that are significantly less stringent than the
ACI 349.3R recommendations can result in the progression of degradation such that it may
impact containment operability.
CONTACT
This IN requires no specific action or written response. Please direct any questions about this
matter to the technical contact listed below or to the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
/RA by TQuay for/ /RA by JTappert for/
Timothy McGinty, 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
Technical Contact:
Abdul Sheikh, NRR
301-415-6004 E-mail: abdul.sheikh@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. surface degradation quantitative acceptance criteria that are significantly less stringent than the
ACI 349.3R recommendations can result in the progression of degradation such that it may
impact containment operability.
CONTACT
This IN requires no specific action or written response. Please direct any questions about this
matter to the technical contact listed below or to the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
/RA by TQuay for/ /RA by JTappert for/
Timothy McGinty, 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
Technical Contact:
Abdul Sheikh, NRR
301-415-6004 E-mail: abdul.sheikh@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 Number: ML101600151 TAC ME3877 OFFICE RASB:DLR Tech Editor BC: RASB:DLR D:DLR LA:PGCB:NRR
NAME ASeikh KAzariah-Kribbs RAuluck BHolian MAG for CHawes
DATE 7/1/2010 06/28/10 e-mail 7/1/2010 7/7/10 07/07/10
OFFICE PM:PGCB:NRR BC:PGCB:NRR D:DCIP:NRO D:DPR:NRR
NAME DBeaulieu SRosenberg(TAlexion for) GTracy (JTappert for) TMcGinty(TQuay for)
OFFICE 07/07/10 07/10/10 07/26/10 08/04/10
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