ML042780609
| ML042780609 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 10/04/2004 |
| From: | Howell A NRC/RGN-IV/DRP |
| To: | Alfred Sanchez NRC Region 4 |
| References | |
| Download: ML042780609 (5) | |
Text
October 4, 2004 MEMORANDUM TO: Alfred A. Sanchez, Jr.
Resident Inspector, Comanche Peak Steam Electric Station FROM:
Arthur T. Howell III, Director /RA/ AVegel for Division of Reactor Projects
SUBJECT:
CHARTER FOR THE SPECIAL INSPECTION TEAM AT RIVER BEND STATION REACTOR SCRAM WITH COMPLICATIONS A.
Basis On October 1, 2004, at approximately 7:19 a.m. (CDT), a fault occurred on Reserve Station Service (RSS) Line #1, causing a loss of the Division I emergency bus which was being supplied from off-site power through RSS1. The Division I emergency diesel generator started and loaded as designed.
At 7:30 a.m., a fault on the main transformer output line caused a generator lock-out, turbine trip, and subsequent reactor scram. The main steam isolation valves were closed by the operators due to lowering main condenser vacuum and lowering main steam line pressure. The reactor was stabilized using the High Pressure Core Spray system and Safety Relief Valves to maintain reactor level and pressure control.
The electrical faults resulted in a loss of main feedwater and condensate systems ability to provide makeup water to the reactor. Additionally, the Reactor Core Isolation Cooling system experienced a steam supply isolation in conjunction with the reactor scram.
In accordance with Management Directive 8.3, NRC Incident Investigation Program, the occurrence of multiple failures in systems used to mitigate an actual event in conjunction with the conditional core damage probability calculated utilizing conditions known to exist during the event comprise sufficient justification to initiate a special inspection.
B.
Scope The team is expected to perform data gathering and fact-finding in order to address the following items:
1.
Develop a complete sequence of events related to the fault on the RSS Line #1 and the subsequent fault on the main transformer, which lead to the reactor scram on October 1, 2004.
Alfred A. Sanchez, Jr. 2.
Evaluate pertinent industry operating experience and potential precursors to the condition, including the effectiveness of any action taken in response to the operating experience.
3.
Review the adequacy of the post-trip review. Include in this review the thoroughness of the licensees assessment of the event and whether potential complications on the plant systems (i.e., extent of conditions) were properly considered, the quality and adequacy of the operability evaluations, and the comprehensiveness and appropriateness of the immediate and long-term corrective actions.
4.
Review the licensee's root cause determination for independence, completeness, and accuracy, including the risk analysis of the event.
5.
Evaluate the adequacy of the operator response to the transient.
6.
Review all pertinent equipment performance, and system responses.
7.
Evaluate and determine the common-cause aspects of the event.
8.
Review the event to determine whether there are any generic issues.
C.
Team Members
- Alfred A. Sanchez, Jr., Resident Inspector and Team Leader
- James Drake, Operations Engineer
- Peter Alter, Senior Resident Inspector to assist as needed D.
Guidance Inspection Procedure 93812, "Special Inspection," dated July 7, 2003, provides additional guidance to be used by the Special Inspection Team.
This memorandum designates you as the Special Inspection Team leader. Your duties will be as described in Inspection Procedure 93812. The team composition will consist of yourself and Mr. James Drake, Operations Inspector, Region IV. Mr. Peter Alter, the River Bend Station Senior Resident Inspector, will provide assistance as needed during the inspection. During performance of the Special Inspection, the designated team member is separated from normal duties and reports directly to you. The team is to emphasize fact-finding in its review of the circumstances surrounding the event. Safety concerns identified that are not directly related to the event should be reported to the Region IV office for appropriate action.
Alfred A. Sanchez, Jr. The Team will report to the site, conduct an entrance, and begin inspection on October 4, 2004. Tentatively, the inspection should be completed by the close of business on October 8, 2004. A formal exit will be scheduled following completion of the on-site inspection. A report documenting the results of the inspection will be issued within 30 days of the completion of the inspection. While the team is onsite, you will provide daily status briefings to Region IV management.
This Charter may be modified should the team develop significant new information that warrants review. Should you have any questions concerning this Charter, contact Mr. David Graves at (817) 860-8141.
Alfred A. Sanchez, Jr. cc via E-mail:
B. Mallett T. Gwynn D. Chamberlain A. Howell A. Vegel A. Gody D. Powers R. Kopriva D. Loveless M. Runyan R. Bywater M. Mitchell, OEDO H. Berkow, NRR R. Gramm, NRR M. Webb, NRR ADAMS: Yes
No Initials: _DNG_____
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