UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

OFFICE OF NUCLEAR REACTOR REGULATION 

OFFICE OF NEW REACTORS 

WASHINGTON, DC 20555-0001 

April 3, 2009 

NRC REGULATORY ISSUE SUMMARY 2009-04 

STEAM GENERATOR TUBE INSPECTION REQUIREMENTS 

ADDRESSEES 

All holders of operating licenses for pressurized-water reactors under the provisions of 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 and applicants for nuclear power plant construction permits, early site permits, and 

limited work authorizations for a pressurized-water reactor under the provisions of 10 CFR 

Part 50, “Domestic Licensing of Production and Utilization Facilities.” 

All holders of and applicants for a combined license, manufacturing license, standard design 

certification, or standard design approval for a pressurized-water reactor under the provisions of 

10 CFR Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants.” 

INTENT 

The Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS) to 

clarify the NRC’s regulatory position on the implementation of the steam generator (SG) tube 

inspection requirements contained within the technical specifications (TS) of a plant. The NRC 

expects addressees to review this RIS for applicability to their facilities and to consider actions 

as appropriate. This RIS requires no action or written response from addressees. 

BACKGROUND INFORMATION 

After public discussions with the NRC staff, the Nuclear Energy Institute Technical Specification 

Task Force (TSTF) submitted a proposal containing performance-based programmatic 

requirements for addressing steam generator tube integrity in the Standard Technical 

Specifications (STS). They designated the proposed changes as TSTF-449, “Steam Generator 

Tube Integrity, Revision 0.” The industry made several revisions to TSTF-449 because of public 

interactions with the NRC staff, including Revisions 1 and 2. On March 2, 2005, the NRC staff 

published a notice for comment (70 FR 10298) of a model no significant hazards consideration 

determination and a model safety evaluation for TSTF-449, Revision 3 to facilitate licensees 

adopting the NRC-staff accepted changes to the STS. 

ML083470557 
RIS 2009-04 

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After minor editorial changes based on stakeholder feedback, the NRC approved Revision 4 to 

TSTF-449 and on May 6, 2005, in accordance with the NRC consolidated line item improvement 

process, issued a notice of availability (70 FR 24126) of the model application, and referenced 

the previously (March 2, 2005) noticed no significant hazards consideration determination and 

model safety evaluation for the adoption of TSTF-449, Revision 4. 

The revised, performance-based, generic TS focus on ensuring that SG tubes satisfy 

performance criteria commensurate with the assurance of adequate tube integrity. All currently 

operating pressurized-water reactor plants have adopted SG TS similar to those in TSTF-449, 

Revision 4. The NRC and the industry have interacted several times concerning proper 

implementation of the new SG tube inspection programmatic requirements, including public 

meetings on May 2, 2007 and November 29, 2007. This RIS clarifies the staff’s position related 

to issues raised by the industry in implementing these inspection requirements. 

The inspection requirements for SG tubes in TSTF-449 depend on the tube material and heat 

treatment these tubes received. The requirements are very similar for the three combinations of 

tube material and tube heat treatment process currently used in the United States. Although the 

following inspection requirements taken from TSTF-449 are directly applicable to units with 

thermally treated Alloy 600 tubes, the issues discussed in the subsequent section of this RIS 

(Summary of Issues) are generally applicable to all steam generators irrespective of the tube 

material and tube heat treatment process. The following is an excerpt from the “Steam 

Generator (SG) Program” section of the TS. 

d. Provisions for SG tube inspections. Periodic SG tube inspections shall 

be performed. The number and portions of the tubes inspected and 

methods of inspection shall be performed with the objective of detecting 

flaws of any type (e.g., volumetric flaws, axial and circumferential cracks) 

that may be present along the length of the tube, from the 

tube-to-tubesheet weld at the tube inlet to the tube-to-tubesheet weld at 

the tube outlet, and that may satisfy the applicable tube repair criteria. 

The tube-to-tubesheet weld is not part of the tube. In addition to meeting 

the requirements of d.1, d.2, and d.3 below, the inspection scope, 

inspection methods, and inspection intervals shall be such as to ensure 

that SG tube integrity is maintained until the next SG inspection. An 

assessment of degradation shall be performed to determine the type and 

location of flaws to which the tubes may be susceptible and, based on 

this assessment, to determine which inspection methods need to be 

employed and at what locations. 

1. Inspect 100% of the tubes in each SG during the first refueling 

outage following SG replacement. 

2. Inspect 100% of the tubes at sequential periods of 120, 90, and, 

thereafter, 60 effective full power months. The first sequential 

period shall be considered to begin after the first inservice 

inspection of the SGs. In addition, inspect 50% of the tubes by 

the refueling outage nearest the midpoint of the period and the 

remaining 50% by the refueling outage nearest the end of the 

period. No SG shall operate for more than 48 effective full power 

months or two refueling outages (whichever is less) without being 

inspected. 
RIS 2009-04 

Page 3 of 5 

3. If crack indications are found in any SG tube, then the next 

inspection for each SG for the degradation mechanism that 

caused the crack indication shall not exceed 24 effective full 

power months or one refueling outage (whichever is less). If 

definitive information, such as from examination of a pulled tube, 

diagnostic non-destructive testing, or engineering evaluation 

indicates that a crack-like indication is not associated with a 

crack(s), then the indication need not be treated as a crack. 

As the industry began to implement the new TS inspection requirements for SG tubes, several 

issues arose concerning acceptable approaches for implementing these new requirements. 

These issues were highlighted to the NRC in a letter from NEI dated September 13, 2007 

(Agencywide Documents Access and Management System (ADAMS) Accession No. 

ML072600574). 

SUMMARY OF ISSUES 

This RIS clarifies the NRC staff’s position related to the implementation of the SG inspection 

requirements in TSTF-449. 

Issue 1: A licensee may identify a new potential degradation mechanism after the first 

inspection in a sequential period. If this occurs, what are the expectations concerning the scope 

of examinations for this new potential degradation mechanism for the remainder of the period 

(e.g., do 100 percent of the tubes have to be inspected by the end of the period or can the 

sample be prorated for the remaining part of the period)?

The TS contain requirements that are a mixture of prescriptive and performance-based 

elements. Paragraph “d” of these requirements indicates that the inspection scope, inspection 

methods, and inspection intervals shall be sufficient to ensure that SG tube integrity is 

maintained until the next SG inspection. Paragraph “d” is a performance-based element 

because it describes the goal of the inspections but does not specify how to achieve the goal. 

However, paragraph “d.2” is a prescriptive element because it specifies that the licensee must 

inspect 100 percent of the tubes at specified periods. 

If an assessment of degradation performed after the first inspection in a sequential period 

results in a licensee concluding that a new degradation mechanism (not anticipated during the 

prior inspections in that period) may potentially occur, the scope of inspections in the remaining 

portion of the period should be sufficient to ensure SG tube integrity for the period between 

inspections. 

In addition, to satisfy the prescriptive requirements of paragraph “d.2” that the licensee must 

inspect 100 percent of the tubes within a specified period, a prorated sample for the remaining 

portion of the period is appropriate for this potentially new degradation mechanism. This 

prorated sample should be such that if the licensee had implemented it at the beginning of the 

period, the TS requirement for the 100 percent inspection in the entire period (for this 

degradation mechanism) would have been met. A prorated sample is appropriate because 

(1) the licensee would have performed the prior inspections in this sequential period consistently 

with the requirements, and (2) the scope of inspections must be sufficient to ensure that the 

licensee maintains SG tube integrity for the period between inspections. 
RIS 2009-04 

Page 4 of 5 

Issue 2: The TS clearly specify the starting point for the first sequential period. What is the 

starting point for the second and subsequent periods (i.e., after the accumulation of the effective 

full-power months listed in the TS or at the end of the last inspection in the previous period)?

The TS specify that the first sequential period begin after the first inservice inspection of the 

SGs. The starting point for the first sequential period is after the first inservice inspection of the 

SGs because the TS specify that the scope of the first inservice inspection is 100 percent of the 

tubes. The starting point for the second and subsequent periods shall be after the accumulation 

of the effective full-power months listed in the TS (e.g., the starting point for the 90 effective full 

power month period is 120 effective full power months after the completion of the first inservice 

inspection. 

Issue 3: Can the refueling outage that is nearest to the midpoint of the period occur after the 

midpoint of the period? Similarly, can the refueling outage nearest the endpoint of the period 

occur after the endpoint of the period?

The inspection nearest the midpoint of the period can be on either side of the midpoint; 

however, the inspection at the end of the period must take place during an outage before the 

end of the period because the TS clearly indicate the scope of the examinations that must be 

performed within the specified periods. 

BACKFIT DISCUSSION 

This RIS provides regulatory clarification and does not represent a new or different staff position 

about the implementation of 10 CFR 50.36, “Technical Specifications.” This RIS clarifies the 

staff’s position related to issues raised by the industry in implementing inspection requirements. 

It requires no action or written response beyond what is required in 10 CFR 50.36. Any action 

that addressees take to implement changes to their TS in accordance with the clarifications in 

this RIS is strictly voluntary, ensures compliance with current regulations, and therefore is not a 

backfit under 10 CFR 50.109, “Backfitting.” Consequently, the NRC staff did not perform a 

backfit analysis. 

FEDERAL REGISTER NOTIFICATION 

A notice of opportunity for public comment on this RIS was not published in the Federal Register 

because the RIS is informational and does not represent a departure from current regulatory 

requirements. However, the NRC held two public meetings on May 2, 2007, and November 29, 

2007 (ML071830174 and ML073470523). These meetings included discussions of steam 

generator inspection methodologies. 

CONGRESSIONAL REVIEW ACT 

The NRC has determined that this RIS is not a rule under the Congressional Review Act 

(5 U.S.C. §§ 801–808) and, therefore, is not subject to the Act. 

PAPERWORK REDUCTION ACT STATEMENT 

This RIS does not contain any information collections and, therefore, is not subject to the 

requirements of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). 
RIS 2009-04 

Page 5 of 5 

PUBLIC PROTECTION NOTIFICATION 

The NRC may not conduct or sponsor, and a person is not required to respond to, a request for 

information or an information collection requirement unless the requesting document displays a 

currently valid Office of Management and Budget control number. 

CONTACT 

Please direct any questions about this matter to the technical contact listed below. 

 Theodore R. Quay for 

 Timothy J. McGinty, Director 

 Division of Policy and Rulemaking 

 Office of Nuclear Reactor Regulation 

Technical Contact: Kenneth J. Karwoski 

(301) 415-2752 

kenneth.karwoski@nrc.gov

Note: The NRC’s generic communications may be found on the NRC public Web site, 

http://www.nrc.gov, under Electronic Reading Room/Document Collections.
RIS 2009-04 

Page 5 of 5 

PUBLIC PROTECTION NOTIFICATION 

The NRC may not conduct or sponsor, and a person is not required to respond to, a request for 

information or an information collection requirement unless the requesting document displays a 

currently valid Office of Management and Budget control number. 

CONTACT 

Please direct any questions about this matter to the technical contact listed below. 

 Theodore R. Quay for 

 Timothy J. McGinty, Director 

 Division of Policy and Rulemaking 

 Office of Nuclear Reactor Regulation 

Technical Contact: Kenneth J. Karwoski 

 (301) 415-2752 

 kenneth.karwoski@nrc.gov

Note: The NRC’s generic communications may be found on the NRC public Web site, 

http://www.nrc.gov, under Electronic Reading Room/Document Collections 

ADAMS ACCESSION NO.: ML083470557 

OFFICE NRR/ADES/DCI Tech Editor DCI/CSGB NRR/ADES/DCI 

NAME KKarwoski See attd. email AHiser MEvans 

DATE 12/01/2008 12/11/2008 12/19/2008 1/12/2009 

OFFICE NRR/ADRO/DORL NRR/DIRS/ITSB NRO/DE/CIB1 

NAME JGiitter RElliott DTerao 

DATE 1/06/2009 1/07/2009 12/17/2008 

OFFICE OE OGC/CRA OGC/NLO NRR/PMDA OIS 

NAME ASapountzis MSmith SUttal LHill GTrussell 

DATE 1/15/2009 12/18/2008 1/28/2009 1/22/2009 1/15/2009 

OFFICE LA: PGCB PGCB BC: PGCB D: DPR 

NAME CHawes CMH SStuchell MMurphy TMcGinty 

DATE 3/6/2009 3/ 6 /2009 4/02/2009 04/03/2009 

Official Record Copy