Event Notification Report for March 06, 2005

SMALL HYDROGEN FLUORIDE LEAK

The following information was obtained from the Paducah Gaseous Diffusion Plant via facsimile (text in quotes);


"At 1140, on 03-6-05, the Plant Shift Superintendent was notified that the C-360 Toll and Transfer Facility Zone 1 PGLD (Process Gas Leak Detection) system (Q Safety System) on # 4 Sample Cabinet actuated. The operators evacuated to the proper assembly point. The emergency Squad entered the building and sampled for Hydrogen Fluoride and sample results were positive. The autoclave and sample cabinet UF6 lines were evacuated and purged. Operators gave bioassay sample and the results indicated an uptake of Uranium. Event investigation is ongoing.

"This event is reportable as a 24 hour event in accordance with the plant procedure UE2-RA-RE1030, Nuclear Regulatory Event Reporting (no 10 CFR section is referenced). An automatic or manual actuation of a Q safety system that results from an event or condition that has the potential for significant impact on the health or safety of personnel. Event having the potential for significant impact are those events where actual plant conditions existed that the system was designed to protect against.

"The NRC Senior Resident Inspector has been notified of this event.

"PGDP Problem Report No. ATRC-05-0892; PGDP Event Report No. PAD-2005-07; Worksheet
Responsible Division: Operations"


Atmospheric leak was on line between the autoclave and the sample cabinet. C-360 Toll and Transfer Facility is a stand alone facility. Operations were secured and two individuals had uptakes (Minimal risk): One had an uptake of 7.3 mg/ liter uranium and the other individual had an uptake level of 5.2 mg/ liter uranium. The limit is 5.0 mg/ liter uranium. There was no smoke (very small leak) and a slight smell of Hydrogen Fluoride caused by the leak.

* * * UPDATE 1230 EST ON 3/24/05 FROM THOMAS WHITE TO S. SANDIN * * *

This report is being retracted based on the following information received from the regulatee via fax:

"This report is being retracted. Subsequent analysis of the actuation determined that the PGLD head actuation occurred from a minor incidental release of UF6 from a valve packing that is not considered a breach of the pressure boundary. Reporting is required if the safety system actuates in response to a condition that the system is designed against and that could result in significant impact on the safety and health of personnel. The PGLD systems safety function, described in the PGDP accident analysis, is to mitigate pigtail/line failures outside of the autoclave that could cause offsite consequences. This incidental UF6 leak did not have the potential for significant impact on personnel or offsite consequences and is not what the safety system is designed to protect against. Thus, the reporting criteria were not met in this case. [The] resident inspector has been notified of this retraction."

Notified R2DO (Ayres) and NMSS (Essig).

POST-ACCIDENT MONITORING INSTRUMENTATION INOPERABLE

The following information was provided by the licensee via facsimile (licensee text in quotes):

"At 1500, on March 6, 2005, the Control Room declared both required divisions for three functions (Primary Containment Pressure, Primary Containment Hydrogen and Oxygen Analyzer, and Drywell Atmosphere Temperature) of Post Accident Monitoring Instrumentation (a Safety System) inoperable. The control room was notified of 'Non Quality' (non-Q) parts installed in both required divisions of a Post Accident Monitoring Instrumentation Recorder. The appropriate LCO Conditions were entered for one or more functions with two required channels inoperable. This equipment has passed all surveillance requirements and has been functional since installation.

"Plans are being developed to replace the non-qualified parts.

"This is being reported as an event or condition that could have prevented fulfillment of a safety function required to mitigate the consequences of an accident in accordance with 10CFR50.72(b)(3)(v)(D)."

The licensee notified the NRC Resident Inspector.


* * * UPDATE ON 03/30/05 @ 1128 BY JIM HUFFORD TO CHAUNCEY GOULD * * * RETRACTION

The following information was provided by the licensee via facsimile (licensee text in quotes):

"On March 6, 2005, PPL Susquehanna, LLC reported a perceived loss of safety function for three functions of Post Accident Monitoring Instrumentation on Unit 1. The notification was made pursuant to the reporting requirements of 10CFR50,72(b)(3)(v)(d). Engineering analysis has subsequently determined that the use of non-Q fuse holders in the Quality application did not adversely affect the safety-related functions which they supported. The fuse holders were removed, subjected to testing, and determined to be electrically and functionally equivalent 'to Quality fuse holders maintained at the station. This analysis conclusion provides the basis for retraction of the ENS report of March 6."

The NRC Resident Inspector was notified.

The Reg 1 RDO (Jim Trapp) was informed.

INVALID SAFETY SYSTEM ACTUATION DURING AN OUTAGE

"This 60-day ENS report is being made per 10CFR 50.73(a)(2)(iv)(A) to report an invalid automatic actuation of systems listed in paragraph (a)(2)(iv)(B), namely ECCS, emergency diesel generator (EDG), and emergency service water (ESW).

"On March 6, 2005 at 15:07 hours a Unit 2 Division 3 LOCA signal was inadvertently initiated during replacement of a power supply on ECCS. Continuity on the 24 VDC power distribution signal common was lost while lifting leads on the power supply. One terminal on the power supply was part of a daisy chain circuit connection. This resulted in an unplanned actuation of the high drywell pressure relays.

"Two 24 VDC power supplies are connected in parallel to supply power to Division 3 ECCS trip units and relays. It was planned to replace one of these power supplies while the power distribution network remained energized by the redundant power supply. However, the continuity of the power distribution network relied on the connection of two leads on one terminal on the out-of-service power supply. When the two leads were separated several relays lost their normal connection to the signal common. Reverse currents caused the false actuation of the Division 3 high drywell pressure relays.

"D23 EDG automatically started and ran unloaded. The C ESW pump automatically started due to the EDG start. The 2A Core Spray (CS) loop received a partial actuation in that the Division 3 signal was initiated but the Division 1 signal was not initiated. 2C CS pump started as designed and 2A CS pump did not start which was expected. The 2A CS loop automatic valve alignment is initiated by the Division 1 signal; therefore, no automatic 2A CS loop valve alignment occurred. All systems functioned as designed during the event.

"The cause of the event was that the work package planner for the power supply replacement failed to recognize the impact on plant systems and as a result applied less than adequate technical rigor. The maintenance planning procedure will be revised to ensure the appropriate level of technical rigor is applied for work packages that lift or manipulate a signal common lead.

"This event Is reportable per 10CFR50.73(a)(2)(iv)(A) since 2C Core Spray pump, D23 EDG and C ESW pump automatically actuated on an invalid signal."

The NRC Resident Inspector has been notified.