05000400/LER-2003-006, Regarding Main Control Room Emergency Filtration System Degradation
| ML033570487 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 12/16/2003 |
| From: | Waldrep B Progress Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| HNP 03-023-153 LER 03-006-00 | |
| Download: ML033570487 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| 4002003006R00 - NRC Website | |
text
Progress Energy DEC 1 6 2003 U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 Serial: HNP-03-153 10CFR50.73 SHEARON HARRIS NUCLEAR POWER PLANT UNIT I DOCKET NO. 50-400/LICENSE NO. NPF-63 LICENSEE EVENT REPORT 2003-006-00 Ladies and Gentlemen:
The enclosed Licensee Event Report 2003-006-00 is submitted in accordance with 10 CFR 50.73. This report describes degradation of the Main Control Room Emergency Filtration System.
Please refer any questions regarding this submittal to Mr. John Caves, Supervisor -
Licensing/Regulatory Programs, at (919) 362-3137.
Sincerely, B. C. Waidrep Plant General Manager Harris Nuclear Plant BCW/rgh Enclosure C:
Mr. R. A. Musser (HNP Senior NRC Resident)
Mr. C. P. Patel (NRC-NRR Project Manager)
Mr. L. A. Reyes (NRC Regional Administrator, Region II)
Progress Energy Carolinas, Inc.
Harris Nuclear Plant P.O. Box 165 New Hill, NC 27562
-- re L--J
Abstract
Harris Nuclear Plant (HNP) personnel conducted surveillance testing of the Control Room Emergency Filtration System (CREFS) on October 17, 2003. Test results were inconsistent with past surveillances; as a result, interim administrative controls were established to ensure CREFS remained operable. An investigation identified two boundary leakage paths that allowed interaction between CREFS and the non-safety ventilation system in an adjacent area.
The condition could have prevented CREFS from meeting its required design function under various operating configurations of the non-safety ventilation system.
The root causes were inadequate design analyses and configuration controls related to the two boundary leakage paths. Corrective actions isolated the two identified leakage paths. Additional corrective actions will ensure the non-safety ventilation system is secured following receipt of a control room isolation actuation.
NIHI IUMM Job 1-UzUW)
(If more space is required, use additional copies of (If more space Is required, use additional copies of (If more space is required, use additional copies of (If more space Is required, use additional copies of NRC Form 366A)
HNP CR 9701088 CR 9701088 identified that the MCR ventilation system developed a positive pressure while operating in recirculation mode (the MCR should not develop a positive pressure while in recirculation). MCR ventilation was shutdown and the positive pressure remained. The cause of the positive pressure in the MCR was attributed to the RAB being at a positive pressure. RAB normal ventilation was in service with one supply fan and three exhaust fans. However, the three exhaust fans were at reduced flowrates, and were unable to maintain a negative differential pressure in the RAB. The interaction of the RAB to the MCR was attributed to air leaks through floor drain loop seals, AH15 loop seals and R2 loop seals.
The investigation and corrective actions from CR 9701088 did not identify the pipe chase as an adjacent area. One of the corrective actions for this event includes defining the MCR boundary and "adjacent areas."
HNP LER 96-007-00, Failure to Perform Technical Specification Surveillance Testing in accordance with Specification 4.7.6.d.3, (Reported 05/28196)
On April 25, 1996 HNP determined that the procedure for performing surveillance testing required by Technical Specification 3/4.7.6, Control Room Emergency Filtration System (CREFS), did not fully implement the 18 month surveillance testing requirements. The test only measured differential pressure for one of five adjacent areas. The cause of the inadequately developed test procedure was due to an incorrect interpretation of the necessary testing.
The cause determination did not identify the all the adjacent areas or identify the influence of the RAB normal ventilation. Corrective actions for this event include revising the surveillance test procedure and defining the MCR boundary and "adjacent area."