ML091120578

Request for Audit of Implementation of Long-Term Stability Solution

ML091120578
Person / Time
Site:	Monticello
Issue date:	04/22/2009
From:	Tam P Plant Licensing Branch III
To:	Gabor S, Loeffler R, Pointer K Northern States Power Co
Tam P
References
TAC MD9990
Download: ML091120578 (4)

Text

Accession No. ML091120578 From: Peter Tam Sent: Wednesday, April 22, 2009 11:52 AM To: 'Pointer, Kenneth'; 'Salamon, Gabor'; 'Loeffler, Richard A.'

Cc: Benjamin Parks; Tai Huang

Subject:

Monticello - Audit of Long-Term Stability Solution for the Proposed EPU Amendment (TAC MD9990)

Ken, Rick:

Northern States Power (NSPM), as the licensee for Monticello Nuclear Generating Plant (MNGP), has recently received NRC approval to implement a new long-term stability solution at MNGP (see Amendment No. 159, 1/30/2009). NSPM is also requesting an extended power uprate (EPU) amendment for MNGP; this request is currently under NRC staff review.

The long-term (L/T) stability solution is a technical matter that receives a significant amount of attention during the NRCs review of the proposed EPU amendment. Accordingly, the NRC staff routinely performs regulatory audits of licensees stability solutions in concert with both the EPU review and as an ongoing regulatory oversight activity with regard to the stability solution installed at domestic boiling water reactors.

Regulatory Bases This audit will be conducted in accordance with the guidelines presented in NRR Office Instruction LIC-111, Regulatory Audits.

The NRC staff will be evaluating the information gained during the audit using the General Design Criteria (GDC) presented in Appendix A to part 50, Title 10, of the US Code of Federal Regulations. Specifically, the NRC staff will consider GDC 10, Reactor Design, GDC 12, Suppression of Power Oscillations, and GDC 13, Instrumentation and Control.

The NRC staff acknowledges that the GDCs are not directly applicable to MNGP, as the plant was not licensed using the GDC. However, the NRC staff believes that the GDCs provide adequate technical guidance against which to evaluate the long-term stability solution installed at MNGP, and will be considering the criteria as regulatory guidance only.

Audit Scope This audit has two main goals: (1) to understand the implementation status of the Monticello Long Term Stability Option implementation, and (2) review the implementation of the ATWS EOPs, including the ATWS/Stability mitigation actions, as it relates to the EPU upgrade.

Information to be Discussed During the Audit The following are items to be covered during the Monticello audit. It will be helpful to have a Monticello presentation of these issues (cover list of items) in the morning and to have a hardware demonstration (control room, testing lab, plant simulator ) in the afternoon.

Questions relating to Implementation of L/T Stability Solutions:

1. Describe the process followed by Monticello to implement L/T Solutions

2. Describe where Monticello is today in the implementation schedule and implementation status.

3. Describe the Monticello Technical Specifications affected by the L/T Solution implementation

4. What is the Monticello experience with the period-based detection algorithm (PBDA)? Noise, false positives, etc.

5. Describe the acceptance testing process. Include a description of PBDA results where false alarms were detected

6. What are the tech spec operability requirements?

7. Describe the backup stability implementation (e.g., interim corrective actions) in MNGP for EPU as well as for the maximum extended load line limit analysis plus (MELLLA+)

operating domain.

8. Describe any Solution-III hardware implementation issues such as: location of the new hardware, periodic testing procedures, cable ringing for verification. Describe any future implications with MELLLA+

9. Describe the implications for operator training. How are false alarms handled?

Questions relating to ATWS, ATWS/Stability, and Emergency Operating Procedures (EOPs)

1. Provide a short summary of the EOPs that apply during ATWS (e.g. level control).

2. Describe how the ATWS/Stability Mitigation Actions are implemented in MNGP EOPs

3. Past ATWS analysis have shown that the suppression pool may reach high temperatures during ATWS. What is the effect on plant equipment (e.g. NPSH)?

4. Describe what effect, if any, the EPU upgrade has on ATWS and EOPs.

5. Provide an ATWS demonstration on the plant simulator with special emphasis on: (1) mitigation of instabilities, (2) effect of EPU (e.g. a comparison of two isolation ATWS transient pre- and post-EPU), (3) if possible, effect of MELLLA+.

Audit Team Assignments The audit will be conducted by the personnel:

(1) Tai Huang, NRR/Reactor Systems Branch, lead reviewer for the MNGP long-term stability solution license amendment; (2) Ben Parks, NRR/Reactor Systems Branch, lead reviewer for MNGP EPU amendment request;

(3) Jose Mach-Leuba, Oak Ridge National Laboratory, technical assistance contractor for MNGP long-term stability and EPU request.

Audit Support Personnel Qualifications Personnel from the licensees staff are requested to include licensed reactor operators, engineers familiar with the long-term stability solution, and engineers and licensing personnel who are or were cognizant of the NRC review of both the EPU request and the long-term stability solution license amendment.

Logistics The audit will be conducted over two days during the week of either May 4 or May 11, 2009, at the Monticello Nuclear Generating Plant.

Deliverables The NRC staff will develop an audit report that summarizes the information gained during the audit and incorporate the audit report into its safety evaluation for the extended power uprate request.

I plan to be onsite to observe the audit, but will not participate in audit activities. Please contact me ASAP to set up a conference call to discuss the above audit plan and make logistical arrangements.

Peter S. Tam Senior Project Manager (for Kewaunee and Monticello)

Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Tel. 301-415-1451 E-mail Properties Mail Envelope Properties ()

Subject:

Monticello - Audit of Long-Term Stability Solution for the Proposed EPU Amendment (TAC MD9990)

Sent Date: 04/22/2009 11:22:43 AM Received Date: 04/22/2009 11:52:00 AM From: Peter Tam Created By: Peter.Tam@nrc.gov Recipients:

Kenneth.Pointer@xenuclear.com ('Pointer, Kenneth')

Tracking Status: None Gabor.Salamon@xenuclear.com ('Salamon, Gabor')

Tracking Status: None Richard.Loeffler@xenuclear.com ('Loeffler, Richard A.')

Tracking Status: None Benjamin.Parks@nrc.gov (Benjamin Parks)

Tracking Status: None Tai.Huang@nrc.gov (Tai Huang)

Tracking Status: None Post Office:

Files Size Date & Time MESSAGE 22895 04/22/2009 Options Expiration Date:

Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: