05000498/LER-2004-002, Inoperable Control Room Makeup and Cleanup Filtration Systems
| ML041420093 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 05/17/2004 |
| From: | Halpin E South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-04001724, STI:31743778 LER 04-002-00 | |
| Download: ML041420093 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| 4982004002R00 - NRC Website | |
text
Nuclear Operating Company SaWtTw f/ld Eicctrlc GanSJ Staton PO. BcP 289 WjdwoWA Teas 77483 May 17,2004 NOC-AE-04001724 STI: 31743778 1 OCFR50.73 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Licensee Event Report LER 1-04-002 Inoperable Control Room Makeup and Cleanup Filtration Systems Pursuant to 1 OCFR50.73, the South Texas Project submits the attached Licensee Event Report 1-04-002 regarding failure to complete a Limiting Condition for Operation (LCO). This event did not have an adverse effect on the health and safety of the public.
On March 17, 2004, with Units 1 and 2 operating in Mode 1, the South Texas Project declared all three trains of Control Room Makeup and Cleanup Filtration Systems (CRMCFS) inoperable in both units. The basis for this conclusion was the fact that the CRMCFS did not maintain the Control Room Envelope (CRE) at sufficient positive pressure relative to adjacent areas during tests performed in March 2003 for Unit 2 and early March 2004 for Unit 1, as required by a surveillance requirement. This event is reportable as a condition prohibited by the Technical Specifications.
There are no commitments contained in this event report.
Resulting corrective actions will be handled in accordance with the South Texas Project Corrective Action Program.
If there are any questions on this submittal, please contact S. M. Head at (361) 972-7136 or me at (361) 972-7849.
E. D. Halpin Plant General Manager jaV Attachment: LER 1-04-002
NOC-AE-04001724 Page 2 of 3 cc:
(paper copy)
(electronic copy)
Bruce S. Mallett Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 Richard A. Ratliff Bureau of Radiation Control Texas Department of Health 1100 West 4 9th Street Austin, TX 78756-3189 Jeffrey Cruz U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP L. D. Blaylock City Public Service Michael K. Webb U. S. Nuclear Regulatory Commission R. L. Balcom Texas Genco, LP A. Ramirez City of Austin C. A. Johnson AEP Texas Central Company Jon C. Wood Matthews & Branscomb C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704
Abstract
At 1242 on 3/17/04, with Units 1 and 2 operating in Mode 1, the South Texas Project (STP) declared all three trains of the Control Room Makeup and Cleanup Filtration Systems (CRMCFS) inoperable in both Units. The basis for this conclusion was the fact that the CRMCFS did not maintain the Control Room Envelope (CRE) at sufficient positive pressure relative to adjacent areas during tests performed in March 2003 for Unit 2 and early March 2004 for Unit 1, as required by a surveillance requirement.
Pursuant to 1 OCFR50.73, STP submits this Licensee Event Report regarding the inoperability of all three CRMCFS trains of each unit as a condition prohibited by the Technical Specifications.
The direct causes of this condition were degraded Unit 1 and Unit 2 CRE system health, coupled with the station's non-conservative interpretation regarding the applicability of the surveillance requirement to certain adjacent areas. The CRMCFS was capable of performing its safety function of limiting control room operator doses to less than 5 rem whole body.
This condition resulted in no personnel injuries, no offsite radiological releases, and no damage to safety-related equipment. There were no challenges to plant safety.
NRC FORM 366 (7-2001)
(If more space Is required, use additional copies of SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES From 3/1 - 3/6/04, STP performed testing to measure unfiltered in-leakage into the Unit 1 CRE in accordance with commitments made in response to Generic Letter 2003-01, "Control Room Habitability." The Component Test method described in NEI 99-03, "Control Room Habitability Guidance," was utilized for this purpose in order to gather data that would support future use of this method in lieu of Tracer Gas Testing, which was considered a less desirable option.
During the test, several test points measured less than the acceptance criteria specified in OPEP05-HE-0002, "Control Room Envelope Differential Pressure Test." Extensive air balancing was unsuccessful in restoring affected test points above the acceptance criteria. The Test Manager and Component Test Project Manager subsequently decided to terminate balancing efforts despite the fact that six test points did not meet the test acceptance criteria. The basis for this conclusion was that the purpose of the testing was to measure in-leakage pursuant to Generic Letter 2003-01, and no in-leakage was detected by virtue of all measured points being positive.
This supported the understanding that the failed points, while representing degraded conditions, did not impact operability, and a correlation to the Technical Specification surveillance requirement that relied on measuring the same parameter was not made. The same determination had been made when concluding Component Testing in Unit 2 in March 2003 with seven test points remaining outside of the acceptance criteria.
On 3/7/04, the NRC Resident Inspectors inquired on the potential impact of the failed measurements on CRMCFS operability. After being briefed regarding the station's position that the failures did not affect operability, the Resident Inspectors expressed their intent to raise the issue with the NRC Regional Office. The following day, the STP Project Manager developed a white paper detailing the station position and forwarded it to the NRC Resident Inspectors to facilitate discussions. Several days of frequent, intensive interactions between the NRC and STP followed.
(if more space is required, use additional copies of (If more space Is required, use additional copies of (It more space Is required, use additional copies of NRC Form 366A) (17)
IV.
CORRECTIVE ACTIONS
A. Develop and implement measures that ensure the optimal system health of the Control Room Envelope. The measures adopted shall consider the overall condition of the CRE, as opposed to narrow measures primarily focused on satisfying associated technical specification surveillance requirements.
B. Revise the Control Room Emergency Air Cleanup System Function Test Procedure to incorporate Component Testing, such that the operability impact of any points that fail to meet minimum differential pressure requirements is clear to the user.
C. Develop and communicate expectations that STP personnel will not assume NRC concurrence with a station position based upon verbal communications.
V.
PREVIOUS SIMILAR EVENTS
LER 1-02-001: CRE HVAC failed to maintain a positive pressure in the Control Room due to the failure of a fire damper. The causes were cited as inadequate communications between operators and engineers, as well as knowledge issues regarding CRE failure modes and appropriate compensatory actions.
VI.
ADDITIONAL INFORMATION
None.
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