Event Notification Report for October 13, 2009

TECHNICAL SUPPORT CENTER UNAVAILABLE DUE TO PLANNED MAINTENANCE

"At 0744 [EDT] on Tuesday, October 13, 2009, the Cook Nuclear Plant (CNP) Technical Support Center (TSC) air conditioning and charcoal filtration systems were removed from service for scheduled maintenance. Under certain accident conditions the TSC may become unavailable due to the inability of the air conditioning and charcoal filtration systems to maintain a habitable atmosphere. Compensatory measures exist to relocate TSC personnel to the unaffected unit's control room if necessary. TSC ventilation system maintenance is scheduled to be completed at 1500 [EDT] on Tuesday, October 13, 2009.

"This notification is being made in accordance with 10CFR50.72(b)(3)(xiii) due to the loss of an emergency response facility."

The licensee notified the NRC Senior Resident Inspector.

* * * UPDATE FROM BUD HINCKLEY TO DONALD NORWOOD AT 1336 EDT ON 10/13/09 * * *

"The CNP TSC ventilation system was returned to functional status following scheduled maintenance at 1333 [EDT] on Tuesday, October 13, 2009.

"This follow-up notification is being made to provide closure from the initial notification under 10CFR50.72.(b)(3)(xiii) due to the loss of an emergency response facility. The licensee has notified the NRC Senior Resident Inspector of the return to service of the TSC Ventilation System."

Notified R3DO (Eric Duncan)

TROXLER MOISTURE DENSITY GAUGE STOLEN FROM OFFICE

A Troxler Model 3440 (S/N 18635) containing two sources, i.e., 8 millicuries Cs-137 and 40 millicuries Am-241/Be, was stolen from the Indiana Department of Transportation field office in Elkhart, Indiana. The field office was broken into during the weekend and Troxler gauge was found missing from a locked closet. The licensee will conduct an investigation and inform their local law enforcement.

The licensee notified the NRC Region 3 Office (Jim Lynch).

THIS MATERIAL EVENT CONTAINS A "CATEGORY 3" LEVEL OF RADIOACTIVE MATERIAL

Category 3 sources, if not safely managed or securely protected, could cause permanent injury to a person who handled them, or were otherwise in contact with them, for some hours. It could possibly - although it is unlikely - be fatal to be close to this amount of unshielded radioactive material for a period of days to weeks. These sources are typically used in practices such as fixed industrial gauges involving high activity sources (for example: level gauges, dredger gauges, conveyor gauges and spinning pipe gauges) and well logging. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

Although IAEA categorization of this event is typically based on device type, the staff has been made aware of the actual activity of the source, and after calculation determines that it is a Category 3 event.

Note: the value assigned by device type "Less than Cat 3" is different than the calculated value "Category 3"

HISTORIC CONDITION WITH CONTAINMENT COOLER FAN RELAYS

"[This is a] historical condition previously reported in LER 2009-001 [that] should also have been reported in accordance with 10 CFR 50.72(b)(3)(v)(D).

"Due to misapplication of Potter and Brumfield Rotary Relays, both operating Containment Air Cooler Fans were declared inoperable on October 13, 2009, and the fans switched from their normal fast speed alignment to the slow speed alignment used for accidents, which eliminated the relay issue and allowed them to be declared operable. This issue was reported in LER 2009-001 as an operation prohibited by the Technical Specifications on December 14, 2009. The fan control circuitry was modified to correct the condition.

"Upon further review, this condition should have been reported per the requirements of 10 CFR 50.72(b)(3)(v)(D) due to both required Containment Air Cooler Fan trains being declared inoperable for the condition. A revision to LER 2009-001 will be submitted per 10 CFR 50.73(a)(2)(v)(D).

"The NRC Senior Resident Inspector has been notified."

NITROUS OXIDE (NOx) GENERATION RATE HIGHER THAN EXPECTED AFTER ALUMINUM FINES WERE INTRODUCED

"Bldg 333's U-Aluminum Bowl Cleaning system is designed to remove uranium from centrifuge bowls by circulating nitric acid through the bowls. The system has historically produced NOx (nitrous oxide, etc) during the nitric acid dissolution process. Safety controls designated as Items Relied On For Safety (IROFS) include a NOx detection system (IROFS BPF-43) with sensors located at the nitric acid knockout column's siphon break potential NOx release point if process ventilation fails and at employee working level.

"On October 13, 2009, NFS began using the Bowl Cleaning system to dissolve U-Al fines (very small particles of U-AI) rather than adding them to the normal dissolver column. The fines were loaded into strainers and placed directly into the bowls to be dissolved with nitric acid. After the dissolution process began, the Operator noticed that the temperature of the system was increasing and that NOx (in the form of a brown cloud) was beginning to form inside the Bowl Cleaning station containment vessels. The system was shutdown. The Nox detector designated as an IROFS alarmed and the facility was evacuated. Immediate corrective actions included building, and health and safety personnel re-entry in SCBA to validate shutdown conditions and remote monitoring of Nox levels in Bldg 333. Based on re-entry data and remote Nox detector readings, Nox levels inside the building (outside of containment) were not significant.

"Laboratory analysis of similar U-AI fines material was conducted October 14-October 16. It behaved in the laboratory in the same manner as what was observed during the operational event. Based on the lab testing, a Nox generation rate specific for the fines material was estimated. Based on engineering calculations, it was determined that the Nox generation for the fines was significantly higher than the previously analyzed Nox generation for the U-AI ingots. The previous Nox evaluation for the U-Al Bowl Cleaning station resulted in an intermediate occupational consequence. Using the generation rate specific for the fines results in high occupational consequences.

"On October 19, 2009, based on the revised Nox generation rate, it was determined that insufficient lROFS were in place and that the performance criteria of 10 CFR 70.61 were not met.

"a) Radiological Hazards involved including: High- enrichment Uranium: quantity Approx 1,000 g; Isotope: U-235 quantity Approx 710 g

"b) Chemical Hazards involved including: Chemical: Nox gas; Quantity: Approx. 1.85 lbs.

"c) Discuss the actual or potential health and safety consequences to the workers, the public, and the environment, including relevant chemical and radiation data for actual personnel exposures to radiation or radioactive materials or hazardous chemicals produced from licensed materials. Include in the discussion below the concentration of chemicals and duration of exposure, if any: Potential worker and public exposure to Nox. Process ventilation and Nox detection worked as designed. No actual exposure to workers or the public were recorded.

"d) Discuss the sequence of occurrences leading to the event, including degradation or failure of structures, systems, equipment, components and activities of personnel relied on to prevent potential accidents or mitigate their consequences: See above.

"e) Discuss whether the remaining structures, systems, equipment components, and activities of personnel relied on to prevent potential accidents or mitigate their consequences are available and reliable to perform their function: IROFS BPF-43 is in place and functioned correctly during the event. Operating personnel responded to the alarm as specified in the operating procedure and evacuated the facility.

"External conditions affecting the event: None.

"Additional actions taken in response to the event: Discussed situation with Operations, Safety management and with the NRC Resident Inspector. The U-Al Bowl Cleaning system is currently not operating."

* * * UPDATE FROM JENNIFER WHEELER TO DONG PARK AT 1005 EDT ON 10/22/09 * * *

The "(nitrous oxide, etc)" in the first paragraph of the original report is updated to state "(NO, NO2, etc)." The licensee has notified the NRC Resident Inspector.

Notified the R2DO (Henson) and NMSS EO (Rubenstone) via email.