05000498/LER-2004-004
| South Texas | |
| Event date: | 04-06-2004 |
|---|---|
| Report date: | 06-07-2004 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(C), 50.54(x) TS Deviation 10 CFR 50.73(a)(2)(iii) |
| 4982004004R00 - NRC Website | |
I.�DESCRIPTION OF REPORTABLE EVENT
A. REPORTABLE EVENT CLASSIFICATION
This event is reportable pursuant to 10CFR50.73(a)(2)(i)(C) and 10CFR50.73(a)(2)(iii).
B. PLANT OPERATING CONDITIONS PRIOR TO THE EVENT
South Texas Project Unit 1 was in Mode 1 operating at 100% power and Unit 2 was in Mode 5 in a refueling outage.
C. STATUS OF STRUCTURES, SYSTEMS, OR COMPONENTS THAT WERE INOPERABLE AT
THE START OF THE EVENT AND THAT CONTRIBUTED TO THE EVENT
Not Applicable.
D. NARRATIVE SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES
On the morning of April 6, 2004, a Tornado Warning was issued for the South Texas Project.
Control Room directed all plant personnel to seek shelter over the public address system at 1140. Security Officers in elevated and ground positions were relocated inside the Mechanical Electrical Auxiliary buildings. Officers at the station checkpoints were relocated to the East Gate House and the Nuclear Support Center. At 1143 a Security Alert was declared by the Security Force Supervisor as defined in the Safeguards Contingency Plan. The adverse weather caused high intrusion detection system alarm rates and loss of assessment capabilities. Security Force personnel were not posted as compensatory actions.
Since the requirements of 10 CFR 73.55(e) and (h) were not met, the Unit 1 Shift Supervisor invoked 10CFR50.54(x) at 1151 for the protection of security personnel. The declaration of a Security Alert is an entry condition into the site Emergency Plan at the Unusual Event level. In accordance with site procedures the Unit 1 Shift Supervisor declared an Unusual Event at 1151 The Owner Controlled Area and Protected Area patrols were secured at 1151 for their safety.
At 1300, after the weather subsided, the security force began recovery by returning to the pre-tornado warning positions. At 1319, the site exited the Security Alert and the Unusual Event. The intrusion detection and threat assessment equipment were tested and compensatory measures established. A search of the Protected Area was conducted and completed satisfactorily at 1422.
E. THE METHOD OF DISCOVERY OF EACH COMPONENT OR SYSTEM FAILURE, OR
PROCEDURAL OR PERSONNEL ERROR
1� Not Applicable II.�COMPONENT OR SYSTEM FAILURES
A. FAILURE MODE, MECHANISM, AND EFFECTS OF EACH FAILED COMPONENT
None
B. CAUSE OF EACH COMPONENT OR SYSTEM FAILURE
None
C. SYSTEMS OR SECONDARY FUNCTIONS THAT WERE AFFECTED BY FAILURE OF
COMPONENTS WITH MULTIPLE FUNCTIONS
None
D. FAILED COMPONENT INFORMATION
None III.�ANALYSIS OF THE EVENT
A. SAFETY SYSTEM RESPONSES THAT OCCURRED
Not Applicable
B. DURATION OF SAFETY SYSTEM TRAIN INOPERABILITY
Not Applicable.
C. SAFETY CONSEQUENCES AND IMPLICATIONS
Not Applicable.
IV. CAUSE OF THE EVENT
The cause of the event was severe weather that included a tornado warning issued for the South Texas Project.
V.�CORRECTIVE ACTIONS None I.P PREVIOUS SIMILAR EVENTS There has been one previous instance where 10CFR50.54(x) was applied due to severe weather conditions at the South Texas Project. The event occurred on July 15, 2003 and was reported to the NRC in LER 1-03-004.