ML020850151

Memo from S. Newberry to J. Strosnider Regarding Indian Point 2 Safety Evaluation Report

ML020850151
Person / Time
Site:	Indian Point
Issue date:	02/26/2002
From:	Newberry S Office of Nuclear Regulatory Research
To:	Strosnider J Division of Engineering
References
FOIA/PA-2001-0256
Download: ML020850151 (3)

Text

MEMORANDUM TO: Jack Stronsnider, Director Division of Engineering FROM:

Scott Newberry, Chairman IP2 Lessons-Learned Task Group

SUBJECT:

IP2 SAFETY EVALUATION REPORT The memorandum that transmitted the Indian Point 2 Steam Generator Tube Failure Lessons Learned Task Group Charter, dated May 24, 2000, states that "should the task group identify concerns or issues that may need to be addressed by Indian Point 2 prior to restart, the group will forward them to the staff for appropriate action."

The purpose of this memorandum is to provide to you our current list of restart review areas consistent with the charter. Along with our lessons learned tasks, this list is a living document derived from the charter and our ongoing discussions and evaluation. [As we work on these issues and gain a more in-depth understanding of the technical arguments, some additional issues may be added and some that are listed may be found to be less relevant to the restart review.] We are not aware that any of these areas are not being pursued, but provide this list to you as we proceed with our effort concurrent with the staff restart review.

We would note that all issues may not be explicitly in the staff safety evaluation report if otherwise resolved or addressed by another aspect of the regulatory process (e.g., regional inspections, etc.).

I appreciate your continuing support for our efforts.

cc:

Roy Zimmerman Brian Sheron John Zwolinski Randy Blough Wayne Lanning Maitri Banergee Joe Donoghue Rick Ennis Tim Frye Jack Goldberg Louise Lund Alan Rubin Jimi Yerokun

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IP2 Lessons Learned Task Group Restart Review Rev. 0, July 14, 2000 Safety Evaluation for Restart

1.

How good/reliable was the licensee's inspection this year? Is the data quality (e.g.,

signal-to-noise ratio from copper deposits, sludge piles, etc.) in the year 2000 inspection good enough to have confidence that flaws in the tubes (i.e., greater than 40% or 70%

through wall) have been found?

2.

Will issues relating to the probability of detection and effective full power days be explicitly addressed in the SE?

3.

Continuous stressing as a result of additional tube bending increases the susceptibility to crack growth. How did Con Ed evaluate the contribution to crack growth resulting from deformation of the SG tubes (i.e., bending)?

4.

Use of the high frequency probe enhances the detection of inside diameter degradation such as PWSCC, and gives us more confidence in the 2000 inspection. Are we concerned about the potential for ODSCC in the U-bends?

5.

What is the technical basis for adequacy of the ODSCC inspection in the sludge pile region, since the high frequency probe would not have provided enhancement for detecting ODSCC.

6.

Is there too much focus by Con Ed and/or NRC staff on inner row U-bend tube failures such that other failure mechanisms/locations are not adequately considered (e.g.,

ODSSC in the free span region above top of the tube sheet (sludge pile))? What measures does the licensee use to consider other failure mechanisms or locations and what criteria are used to evaluate other mechanisms/locations if encountered?

7.

We now understand that, in all likelihood, the licensee is not capable of detecting cracks in the row 3 U-bends at 40% throughwall with 80% probability of detection with 95%

confidence. What alternative to this criteria is acceptable to the staff?

8.

Is sufficient attention being paid to PWSCC in the U-bend region of the low row SG tubes (i.e., row 3 and higher, since all the row 2 tubes have been plugged)?

9.

Have appropriate inspections/condition monitoring/operational assessment/corrective actions been taken to have necessary confidence that the tubes will meet structural and leakage integrity (considering any potential degradation mechanism in any region of the tubes) until the current SGs are replaced?

10.

Are the issues contained in the research review findings adequately addressed in the SE? (e.g., inadequate operational assessment - no growth rates or NDE uncertainty; significance of new forms of degradation - ODSCC at sludge pile and PWSCC in U-bends; whether dubious licensee arguments were considered in SE findings).

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11.

Does the SE consider one of the potential lessons learned, which is "SERs prepared by NRC,should clearly state the-bases for the conclusions reached and clearly identify lic;nsee information not 'reliedupon as part of the bases."

Regional Issues/Others

12.

Will issues on inadequate root cause and corrective actions with respect to SG integrity addressed in the SE?

13.

If there are differences between the licensee's Root Cause (s) and the NRC's Special Inspection Team's Root Cause(s) (there are), then can we have reasonable confidence that IP2's corrective actions will prevent recurrence?

14.

In a practical sense, how will the EPRI guidelines be used for their next cycle at IP2?

For example, how are the EPRI guidelines for primary to secondary leakage (both absolute values and rate-of-change values) being incorporated into their performance during their next cycle? [In the tranmittal letter from NEI to NRC for NEI 97-06, NEI promises "Each licensee will evaluate its existing steam generator program and, where necessary, revise and strengthen program attributes to meet the intent of the guidance provided in NEI 97-06, Steam Generator Program Guidelines, no later than the first refueling ouage starting after January 1, 1999." It is our understanding that the EPRI guidelines would become the basis for the licensee procedures.]

15.

Has the NRC communicated to the public and other stakeholders, in plain English, the basis for the restart decision, including the risk to the public from the operation of IP2 for a limited period of time with the current SGs?