05000395/LER-2003-001
| Virgil C. Summer Nuclear Station | |
| Event date: | 04-22-2003 |
|---|---|
| Report date: | 06-13-2003 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3952003001R00 - NRC Website | |
PLANT IDENTIFICATION
Westinghouse - Pressurized Water Reactor
EQUIPMENT IDENTIFICATION
DRIB/107
IDENTIFICATION OF EVENT
On April 22-23, 2003, steam propagation barrier door DRIB/107 was first discovered chained and strapped open and later found blocked open. The door was in this configuration to allow cooling for the Security Officer assigned to continuously monitor two drums of refrigerant stored in the room.
The door was immediately returned to the required position and the Security force was trained on the proper control of doors/barriers in the plant.
EVENT DATE
04/22./03
REPORT DATE
06/13/03
CONDITIONS PRIOR TO EVENT
Mode 1, 100% Power
DESCRIPTION OF EVENT
On April 22-23, 2003 Security Officers were assigned to continuously monitor two drums of refrigerant while maintenance was being performed on "C" HVAC chiller, which is the swing component. After the maintenance crew completed work on April 22, the drums were continuously monitored throughout the night as required by station security procedure. Door DRIB/107 is a double door designed as a steam propagation barrier for protection of the HVAC chillers and pumps from harsh environment during a steam
DESCRIPTION OF EVENT
line break. The temperature in the chiller room behind the door is relatively hot and not conducive to long stay times. As a result, a Security Officer opened the door in order to cool himself by securing one side of the door with a hoist chain and the other with a lifting strap.
During his rounds, an Operations Test Specialist noticed the door secured open and notified the duty Shift Supervisor. The door was returned to the closed position and the Security Officer was informed as to the required position of the door.
During shift rounds on the morning of April 23, the Auxiliary Building Operator found the door open again by another Security Officer who was standing with his back against the door. The Auxiliary Building Operator closed the door and informed the Security Officer as to the required position of the door.
With DRIB/107 open, both trains of Chilled Water are considered inoperable due to steam line break accident environment. This condition results in both trains of Control Room Ventilation being inoperable. This condition is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B).
Investigation of the event determined that the maximum time the door was opened for any given time was four hours and forty minutes. Fire protection procedures specifically address steam propagation barriers in that doors may be opened for normal ingress and egress only. However, it was determined that Security training does not include requirements for steam propagation barrier doors.
In addition to immediately returning the door to the required position, immediate corrective actions included Security training addressing the proper control of doors/barriers in the plant and that no door in the plant should be used for anything other than normal ingress/egress without prior approval from Operations.
Condition Event Report C-03-1364 was generated to address the event and to perform a root cause evaluation to understand why the event happened and to design effective corrective actions.
CAUSE OF EVENT
The cause of this event is a lack of specific training for the Security force on the requirements for steam propagation barrier doors.
ANALYSIS OF EVENT
During the investigation of this event, it was discovered that a Security Officer had restrained DRIB/107 in the open position using a hoist chain and lifting strap in an effort to provide cooling to himself in a hot environment. Another Security Officer used his body to block the door for cooling.
While the door was opened beyond normal ingress/egress, both trains of Chilled Water were considered inoperable which resulted in both trains of Control Room Ventilation being inoperable.
CORRECTIVE ACTIONS
The door was immediately returned to the required position when discovered open on both occasions. The Security force was trained on the requirements for steam propagation barrier doors in the plant. The event was documented in Condition Event Report C-03-1364 and root cause evaluation RCA03-1364 was performed. As an immediate interim measure, an information notice on Steam Propagation Barrier doors was provided to all personnel. Steam Propagation Barrier awareness training will be provided to all site personnel during initial and annual Station Orientation Training.
PRIOR OCCURRENCES
In August 2002, a non-cited violation (NCV) evaluated as having very low safety significance (Green) was issued for failure to follow procedural controls for steam propagation barrier doors. During the post maintenance testing process for a diesel generator jacket water heater replacement, the water fill hose was routed through a steam propagation barrier (SPB) door. Operators performing the fill evolution did not understand that routing a hose through the door did not constitute minor maintenance. Procedurally, SPB doors could remain open for up to one hour for minor maintenance. After discussions with control room supervision the activity was suspended until the alternate method of supplying water was implemented.
In order to prevent recurrence Condition Event Report (CER) C-02-2704 was generated with the following corrective actions.
- Fire Protection Procedure, FPP-025, Revision 3, Change E was issued 11/20/02 to clarify that minor maintenance applies only to the respective door.
- Station Operating Procedure, SOP-306, Revision 15, Change B was issued 11/11/02 to add mode requirements to which valve (or which door) is used to fill the expansion tank.
- Enhancements to Licensed/Auxiliary Operator Initial and Requal programs are being made to include training modules consisting of Steam Propagation Barriers, Flood Bathers and Fire Barriers. This action is scheduled for completion in December, 2003.
- A synopsis of CER C-02-2704 was included in the October 2002 Operator Required Reading.
SCE&G believes that completion of actions identified for the prior occurrence, supplemented by those for the most recent event, will ensure future compliance.