ML040090131
| ML040090131 | |
| Person / Time | |
|---|---|
| Issue date: | 03/16/2004 |
| From: | Boger B NRC/NRR/DIPM |
| To: | Floyd S Nuclear Energy Institute |
| Hickman D, NRR/DIPM 415-8541 | |
| References | |
| G20030670, TAC MC1357 | |
| Download: ML040090131 (5) | |
Text
March 16, 2004 Stephen D. Floyd Vice President, Regulatory Affairs Nuclear Generation Division Nuclear Energy Institute 1776 I Street, NW Suite 400 Washington, DC 20006-3708
Dear Mr. Floyd:
I am responding to your October 31, 2003, letter regarding performance indicator (PI) IE-02, Unplanned Scrams with Loss of Normal Heat Removal. Your views on the scrams with loss of normal heat removal PI are appreciated and the staff has given serious consideration to your recommendation that this PI be eliminated. In addition to sharing similar concerns about this PI, we are concerned about the status of activities related to the PI program as a whole, including the resolution of issues raised by licensees through the frequently asked questions (FAQ) process. We consider the timely resolution of FAQs to be a very important aspect of the PI program. As discussed at the public Nuclear Regulatory Commission (NRC)/Nuclear Energy Institute (NEI) senior management meeting on December 18, 2003, we consider the time and resources recently required to address PI issues to be neither efficient nor effective.
The four points raised in your letter are discussed in an attachment to this letter. The staff concludes that it would be premature to eliminate the scrams with loss of normal heat removal PI at this time. However, based upon the importance of an indicator which monitors complex scrams and the need to improve its usefulness, we conclude that a fresh look at the PI and the implementation issues associated with it is appropriate.
Over the last several years, the staff and industry have attempted to better define what constitutes a loss of the normal heat removal path. While it is true in hindsight that the PI could have been better defined in the beginning and that the definition of what constitutes a scram with loss of normal heat removal has changed several times since then, some of the issues discussed in your letter have been resolved through the FAQ process. During the last two years, the staff has proposed a number of alternatives in an attempt to reach agreement with the industry on a clear and appropriate definition for this PI. We believe we can find an acceptable definition for this PI that more appropriately addresses plant transients beyond a routine scram and ask for NEIs support in meeting this goal.
Regarding the FAQ process, when the ROP was initially implemented, the FAQ panel members were focused on broad implementation issues that needed resolution in order for the concept to succeed. Over time, that focus has shifted to plant specific issues. NEIs support is also requested in returning the panels focus to the broad implementation of the PI program.
Mr. S. Floyd In summary, the staff believes that a PI that identifies plant transients beyond routine scrams that have risk-significance in some important accident sequences has merit, and is presently worth retaining. The scrams with loss of normal heat removal PI provides a performance insight that is not obtainable from the unplanned scrams PI or the significance determination process. We will be in contact with NEI shortly to discuss the next steps in finding an acceptable definition for the scrams with loss of normal heat removal PI.
Sincerely,
/RA/
Bruce A. Boger, Director Division of Inspection Program Management Office of Nuclear Reactor Regulation
Attachment:
As stated
Mr. S. Floyd In summary, the staff believes that a PI that identifies plant transients beyond routine scrams that have risk-significance in some important accident sequences has merit, and is presently worth retaining. The scrams with loss of normal heat removal PI provides a performance insight that is not obtainable from the unplanned scrams PI or the significance determination process. We will be in contact with NEI shortly to discuss the next steps in finding an acceptable definition for the scrams with loss of normal heat removal PI.
Sincerely, Bruce A. Boger, Director Division of Inspection Program Management Office of Nuclear Reactor Regulation
Attachment:
As stated DISTRIBUTION:
W. Travers W. Kane J. Craig L. Reyes, RII P. Norry S. Collins W. Borchardt J. Caldwell, RIII C. Paperiello W. Dean C. Carpenter B. Mallett, RIV J. Dyer A. Thadani H. Miller, RI FAST G20030670 Accession Number:ML040090131 OFFICE:
DIPM/IIPB DIPM/IIPB:SC DIPM/IIPB:BC DIPM:D NAME:
DHickman*
JAndersen*
SRichards*
BBoger* CAC for DATE:
01/16/2004 01/16/2004 03/03/2004 03/16/2004 OFFICIAL RECORD COPY
Unplanned Scrams with Loss of Normal Heat Removal Performance Indicator (PI)
Discussion of Four Key Points from Letter dated October 31, 2003 The Nuclear Energy Institutes (NEIs) letter dated October 31, 2003, lists four key points that NEI believes supports elimination of Performance Indicator (PI) IE-02, Unplanned Scrams with Loss of Normal Heat Removal. The following provides the key points discussed in NEIs letter, and the NRC response.
Issue #1: The PI is duplicative of the existing performance indicator IE-01, Unplanned Scrams per 7000 Critical Hours.
NRC Response: Scrams with loss of normal heat removal constitute a class of events, important to plant safety in certain accident sequences, that have sufficient data to be useful as a performance indicator. In the event of a transient, maintaining the availability of the normal heat removal path can preclude the plant from relying on safety systems to remove decay heat, or can lessen the probability of a more severe event developing in the event of a failure of these safety systems. The value from this PI is the ability to identify an adverse trend (over a 12 calendar quarter period) in plant equipment that plays an important role in safely shutting down a nuclear power plant. The unplanned scrams PI does not accomplish this.
Issue #2: The NRC inspection practice of assessing every reactor scram, including scrams with loss of normal heat removal, and considering any associated findings in the significance determination process. The NEI letter concludes in part that the scrams with loss of normal heat removal PI adds no value because of these activities.
NRC Response: Under the reactor oversight process (ROP), the performance indicators are combined with inspection findings to determine in which response column of the Action Matrix a reactor unit is placed. The response column helps define the scope and depth of supplemental inspection activities at a site. In this manner, the scrams with loss of normal heat removal PI, combined with other PIs and inspection findings, potentially has a much greater impact on NRC inspection activities than may occur from the inspection of every scram. For example, the transition of the scrams with loss of normal heat removal PI from green to white could result in a reactor unit moving into the Degraded Cornerstone column from the Regulatory Response column or from the Degraded Cornerstone column into the Multiple/Repetitive Degraded Cornerstone column (assuming other greater than green inspection findings/performance indicators exist). The supplemental inspections performed in the Degraded Cornerstone and Multiple/Repetitive Degraded Cornerstone columns are typically much broader in scope than the follow-up to a reactor scram. Repeated losses of the normal heat removal path during plant scrams, trended over 12 calendar quarters, is a valid input to consider when deciding whether to expend supplemental inspection resources to determine if more wide spread performance deficiencies exist.
Attachment Issue #3: There is no evidence or analysis to suggest that this is a leading indicator or a precursor of degraded performance.
NRC Response: The majority of the ROP PIs are not leading indicators or precursors of degraded performance. Not withstanding that, as discussed above, a PI that includes the more complicated scrams, including a loss of normal heat removal path, is considered by the NRC to be a valid input to the Action Matrix.
Issue #4: This PI has been an inordinate resource burden for the industry and the NRC staff in dealing with its intent and complexity. This PI has contributed to extended and inconclusive debate within the FAQ panel, which is comprised of both industry representatives and NRC staff, and has resulted in delayed submission of PI inputs from licensees.
NRC Response: In order for the PIs and inspection findings to properly risk-inform the NRC inspection process, the PI inputs must occur in a timely manner. As the NRC staff and NEI have previously discussed and agreed, the process for evaluating and resolving FAQ's will be modified to allow for adequate discussion by the FAQ panel and timely FAQ resolution. Going forward, FAQ's will be introduced during a monthly ROP meeting and discussed, if necessary, for two subsequent meetings. If after that time a consensus does not exist between the licensee representatives and the NRC staff, the NRC staff will determine the resolution. NEI will then incorporate the NRC resolution into the FAQ database by the next ROP meeting and into the next revision of NEI 99-02, if necessary. The final staff resolution will be made by the NRC Chief, Inspection Program Branch, and any industry appeal, if desired, will be directed to and addressed by the NRC Director, Division of Inspection Program Management.