05000454/LER-2006-001
| Docket Number | |
| Event date: | 01-24-2006 |
|---|---|
| Report date: | 03-24-2006 |
| 4542006001R00 - NRC Website | |
B. Description of Event:
On January 23, 2006, at approximately 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, a Chemistry Technician (CT) (non-licensed) was performing daily reactor coolant [AB] sampling activities. During this sampling activity he noted an abnormal condition with the pressurizer liquid space sample line in that he was able to obtain sample flow at the panel with the Pressurizer Liquid Sample Isolation Valve (1PS9350B) closed, the Pressurizer Liquid Inboard Containment Isolation Valve (1PS9355A) closed and the Pressurizer Liquid Outboard Containment Isolation Valve (1PS9355B) closed. The CT did not notify Shift operations and did not notify his Chemistry Supervisor (CS) (non-licensed) of this abnormal condition until approximately 1230 hours0.0142 days <br />0.342 hours <br />0.00203 weeks <br />4.68015e-4 months <br />. A Corrective Action Program (CAP) Issue Report (IR) was not generated to document the abnormal condition.
Not realizing the potential significance of the abnormal condition from a containment integrity perspective, the CS decided to perform a preliminary investigation/troubleshooting effort to gain more information before documenting the issue in an IR. After this preliminary effort, the CS wrote the IR the next morning on January 24, 2006, at 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br />. The CS did not promptly notify Shift Operations to screen the IR for operability.
Consequently, the IR was not identified as needing an operability determination until subsequent IR screening activities on the morning of January 25, 2006. The Shift Manager then engaged the appropriate plant staff to assess the abnormal condition and provide additional information to make an operability determination of the containment isolation valves involved.
The additional information provided to the Shift Manager could not support a reasonable expectation that the 1PS9355A and 1PS9355B containment isolation valves could perform their design function. Consequently, the valves were declared inoperable at 1250 hours0.0145 days <br />0.347 hours <br />0.00207 weeks <br />4.75625e-4 months <br /> on January 25, 2006 and Technical Specification 3.6.3, "Containment Isolation Valves," Required Actions A and B were entered. These actions require that the containment penetration be isolated within one hour by a closed and deactivated automatic or remote manual valve, closed manual valve, or blind flange. This was accomplished by 1350 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.13675e-4 months <br />. This event is reportable to the NRC in accordance with 10 CFR 50.73 (a) (2) (i) (B), as an event or condition prohibited by Technical Specifications.E Even though all Technical Specification actions were accomplished within the required completion times there was firm evidence to indicate the inoperable condition existed on the day before when the IR was generated. The operability evaluation and subsequent inoperability declaration should have occurred on January 24, 2006.
NRC FOM 366A (7-2001) (7-2001) FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) Byron Station 0500454 2006 001 (If more space is required, use additional copies of NRC Form 366A)(17)
C. Cause of the Event
The cause of this event was inadequate understanding within the Chemistry department concerning the threshold of when to report equipment issues to Shift Operations. Not recognizing the containment integrity aspects of this abnormal condition, the CT and CS involved did not believe the condition was significant enough to warrant prompt Shift Operations notification. In addition, the CS and CT involved failed to document the abnormal condition in the CAP in a timely manner.
D. Safety Analysis
This event had minimal safety consequences. The penetration flow path was always isolated during this delay period consistent with the Technical Specification required action except for one of the valves utilized to isolate the flow path was an automatic valve, which was closed but not deactivated. This valve was not intentionally nor inadvertently opened.
E. Corrective Actions
Expectations for prompt supervisor notification and IR initiation concerning equipment issues have been reinforced with Chemistry Department personnel.
Expectations for the prompt notification of Shift operations concerning equipment issues have been reinforced with Chemistry Department personnel.
Appropriate management actions have been performed with the CT and CS involved for their failure to follow CAP requirements.
The causes of the containment isolation valves' failure are unknown and will be further investigated and repaired in the fall 2006 refuel outage.
F. Previous Occurrences
There have been no previous LER occurrences of this nature at Byron in the previous 2 years.