ML102700614

Part 21 60-Day Interim Report Notification: Failure to Include Seismic Input in Channel-Control Blade Interference Customer Guidance

ML102700614
Person / Time
Site:	Hatch, Monticello, Dresden, Peach Bottom, Browns Ferry, Nine Mile Point, Perry, Fermi, Oyster Creek, Hope Creek, Grand Gulf, Cooper, Pilgrim, Susquehanna, Columbia, Brunswick, Limerick, River Bend, Vermont Yankee, Duane Arnold, Clinton, Quad Cities, FitzPatrick, LaSalle
Issue date:	09/27/2010
From:	Porter D E GE-Hitachi Nuclear Energy Americas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
MFN 10-245 Rev. 1
Download: ML102700614 (7)

Text

GE Hitachi Nuclear Energy

September 27, 2010 MFN 10-245 Revision 1 Attn: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Part 21 60-Day Interim Report Notification: Failure to Include Seismic Input in Channel-Control Blade Interference Customer Guidance

Reference:

GEH Letter to NRC, Part 21 60-Day Interim Report Notification: Failure to Include Seismic Input in Channel-Control Blade Interference Customer Guidance, September 2, 2010, MFN 10-245 GEH Letter to NRC, Update to GEH Surveillance Program for Channel-Control Blade Interference Monitoring, December 19, 2008, MFN 08-420 This letter provides a revision to the information transmitted on September 2, 2010 in MFN 10-245 concerning an evaluation being performed by GE Hitachi Nuclear Energy (GEH) regarding the failure to include seismic input in channel-control blade interference customer guidance. Two changes have been made in Revision 1:

• A statement was added regarding the applicability of this issue to the ABWR and ESBWR design certification documentation.

• The original MFN 10-245 referenced the Safety Communication SC 08-05 R1 that was transmitted to the US NRC via MFN 08-420. The references to SC 08-05 were changed to MFN 08-420 to prevent possible confusion. As stated herein, GEH has not concluded that this is a reportable condition in accordance with the requirements of 10CFR 21.21(d) and continued evaluation is required to determine the impact of a seismic event on the guidance contained in MFN 08-420.

The information required for a 60-Day Interim Report Notification per §21.21(a)(2) is provided in Attachment 3. The commitment for follow-on actions is provided in Attachment 3, item (vii).

Dale E. Porter GE-Hitachi Nuclear Energy Americas LLC Safety Evaluation Program Manager 3901 Castle Hayne Rd., Wilmington, NC 28401 USA T 910 819-4491 Dale.Porter@GE.Com MFN 10-245 Revision 1 Page 2 of 2 If you have any questions, please call me at (910) 819-4491.

Sincerely, Dale E. Porter Safety Evaluation Program Manager

GE-Hitachi Nuclear Energy Americas LLC

Attachments: 1. Description of Evaluation 2. US Plants Previously Notified of Channel-Control Blade Interference Concerns

3. 60-Day Interim Report Notification Information per §21.21(a)(2) cc: S. S. Philpott, USNRC S. J. Pannier, USNRC O. Tabatabai-Yazdi, USNRC J. F. Harrison, GEH J. G. Head, GEH P. L. Campbell, GEH Washington A. A. Lingenfelter, GNF

PRC File DRF Section No. 0000-0122-6045

MFN 10-245 Revision 1 Attachment 1 Page 1 of 2 Attachment 1

- Description of Evaluation Summary GE Hitachi Nuclear Energy (GEH) has identified that engineering evaluations that support the guidance provided in MFN 08-420, do not address the potential impact of a seismic event on the ability to scram as it relates to the channel-control blade interference issue. Note that the seismic loads are not a consideration in the scram timing, but rather the ability to insert the control blades. In other words, the control blades must be capable of inserting during the seismic event, but not to the timing requirements of the Technical Specifications. GEH is evaluating the impact of the seismic loads between the fuel channel and the control blade associated with an Operating Basis Earthquake (OBE), and a Safe Shutdown Earthquake (SSE) on BWR/2-5 plants. The scram capability is expected to be affected due to the added seismic loads at low reactor pressures in the BWR/2-5 plants. The ability to scram for the BWR/6 plants is not adversely affected by the seismic events. Additional evaluation is required to determine to what extent the maximum allowable friction limits specified for the BWR/2-5 plants in MFN 08-420 is affected by the addition of seismic loads.

GEH issues this 60-Day Interim Report in accordance with the requirements set forth in 10CFR 21.21(a)(2) to allow additional time to for this evaluation to be completed.

Background In 2008, GEH issued Safety Communication MFN 08-420, that provided guidance for monitoring plants for channel-control blade interference while maintaining acceptable scram performance under normal, transient, and low pressure conditions for BWR/2-6 plants.

Recently it was discovered that the basis for that Safety Communication did not address the affects of a seismic event on the ability to insert the control blades and affect a shutdown when a scram is demanded. GEH continues to evaluate the impact of the seismic events on the guidance provided in MFN 08-420.

Evaluation

To date GEH has determined the following:

1. The required scram performance for the BWR/6 plant is not adversely impacted by the seismic events. The guidance specified in MFN 08-420 continues to ensure that the BWR/6 control rods will fully insert during a seismic event (OBE or SSE). 2. For the BWR/2-5 plants, at reactor pressures of 1000 psig and above, the required scram capability is not adversely impacted by the seismic events (OBE of SSE). The MFN 10-245 Revision 1 Attachment 1 Page 2 of 2 guidance specified in MFN 08-420 will continue to ensure that the BWR/2-5 control blades will fully insert during a seismic event (OBE or SSE). 3. For the BWR/2-5 plants, the potential exists that during a seismic event, control blades with scram friction near the limits specified in MFN 08-420, may not fully insert at the main steam isolation valve (MSIV) isolation pressure condition, or at a 550 psig pressure condition as defined in the Safety Communication. 4. It is unlikely that a Substantial Safety Hazard exists for BWR/2-5 plants currently operating under the guidance provided in MFN 08-420 based upon the following: a. The evaluation completed to date indicates that this issue applies only to the BWR/2-5 plants, and only for low-pressure scram conditions. b. For control blades exhibiting channel-control blade interference as described in MFN 08-420, it is expected that these control blades will completely or partially insert upon scram during a seismic event, even at lower pressure conditions. c. Any control blade that did not fully insert during the seismic event can be inserted manually, either by normal control blade insertion or by resetting and re-scramming the particular control blade. d. The time spent at low reactor pressure is limited.

ABWR and ESBWR Design Certification Documentation Applicability The issues described above have been reviewed for applicability to documentation associated with 10CFR 52 and it has been determined that there is no affect on the technical information contained in either the ABWR certified design or the ESBWR design in certification.

Recommendation

To assist in a control blade insertion under the low-pressure condition, the accumulator pressure for no-settle control blades may be increased as described in MFN 08-420 Table 2-3 or the control blade inserted manually prior to operating at a reactor pressure less than 1000 psig.

Corrective/Preventive Actions GEH will complete the following evaluations on the dates specified herein. This task will be

completed by December 15, 2010.

Refer to Attachment 3, Item (vii) for corrective actions.

MFN 10-245 Revision 1 Attachment 2 Page 1 of 1 Attachment 2

- US Plants Previously Notified of Channel-Control Blade Concerns (1) = Surveillance program recommended (2) = Provided for information (1) (2) Utility Plant X Constellation Nuclear Nine Mile Point 1 X Constellation Nuclear. Nine Mile Point 2 X Detroit Edison Co. Fermi 2 X Energy Northwest Columbia X Entergy Nuclear Northeast FitzPatrick X Entergy Nuclear Northeast Pilgrim X Entergy Nuclear Northeast Vermont Yankee X Entergy Operations, Inc. Grand Gulf X Entergy Operations, Inc. River Bend X Exelon Generation Co. Clinton X Exelon Generation Co. Oyster Creek X Exelon Generation Co. Dresden 2 X Exelon Generation Co. Dresden 3 X Exelon Generation Co. LaSalle 1 X Exelon Generation Co. LaSalle 2 X Exelon Generation Co. Limerick 1 X Exelon Generation Co. Limerick 2 X Exelon Generation Co. Peach Bottom 2 X Exelon Generation Co. Peach Bottom 3 X Exelon Generation Co. Quad Cities 1 X Exelon Generation Co. Quad Cities 2 X First Energy Nuclear Operating Co. Perry 1 X FPL Energy Duane Arnold X Nebraska Public Power District Cooper X Nuclear Management Co. Monticello X PPL Susquehanna LLC. Susquehanna 1 X PPL Susquehanna LLC Susquehanna 2 X Progress Energy Brunswick 1 X Progress Energy Brunswick 2 X PSEG Nuclear. Hope Creek X Southern Nuclear Operating Co. Hatch 1 X Southern Nuclear Operating Co. Hatch 2 X Tennessee Valley Authority Browns Ferry 1 X Tennessee Valley Authority Browns Ferry 2 X Tennessee Valley Authority Browns Ferry 3

MFN 10-245 Revision 1 Attachment 3 Page 1 of 2

Attachment 3 Day Interim Report Notification Information per §21.21(a)(2)

(i) Name and address of the individual or individuals informing the Project.

Dale E. Porter

GE Hitachi Nuclear Energy Safety Evaluation Program Manager 3901 Castle Hayne Road, Wilmington, NC 28401 (ii) Identification of the facility, the activity, or the basic component supplied for such facility which fails to comply or contains a defect.

See Attachment 2 for a list of potentially affected plants (iii) Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.

GE Hitachi Nuclear Energy

(iv) Nature of the defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply.

GE Hitachi Nuclear Energy (GEH) has identified that engineering evaluations that support the guidance provided in MFN 08-420, do not address the potential impact of a seismic event on scram performance as it relates to the channel-control blade interference issue. GEH is evaluating the impact of the seismic loads between the fuel channel and the control blade associated with an Operating Basis Earthquake (OBE), and a Safe Shutdown Earthquake (SSE) on BWR/2-5 plants. The scram capability is expected to be affected due to the added seismic loads at low reactor pressures in the BWR/2-5 plants. The scram capability for the BWR/6 plants is not adversely affected by the concurrent seismic events. Additional evaluation is required to determine to what extent the maximum allowable friction limits specified for the BWR/2-5 plants in MFN 08-420 is affected by the addition of seismic loads.

(v) The date on which the information of such defect or failure to comply was obtained.

A Potential Reportable Condition Evaluation in accordance with 10CFR Part 21 was initiated on July 7, 2010.

(vi) In the case of a basic component which contains a defect or fails to comply, the number and location of these components in use at, supplied for, being supplied for, or may be supplied for, manufactured, or being manufactured for one or more facilities or activities subject to the regulations in this part.

See Attachment 2 for a list of potentially affected plants.

(vii) The corrective action, which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action.

MFN 10-245 Revision 1 Attachment 3 Page 2 of 2

GEH will complete the following evaluations on the dates specified herein. This task will be completed by December 15, 2010.

Elements of the evaluation will include friction estimates under seismic conditions and re-evaluation of the MFN 08-420 recommendations.

(viii) Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees.

To assist in a control blade insertion under the low-pressure condition, the accumulator pressure for no-settle control blades may be increased as described in MFN 08-420 Table 2-3 or the control blade inserted manually prior to operating at a reactor pressure less than 1000 psig.

(ix) In the case of an early site permit, the entities to whom an early site permit was transferred.

This is not an early site permit concern.