Event Notification Report for July 12, 2010

PLANNED TECHNICAL SUPPORT CENTER OUTAGE

"A condition is being reported per Technical Requirements Manual 13.13.1 Emergency Response Facilities Action B.2. The functionality of the Technical Support Center (TSC) has been lost due to planned maintenance being performed on the TSC HVAC.

"Alternate facilities are available to provide emergency response functions and actions are proceeding to return the TSC to FUNCTIONAL status with high priority. A 10CFR50.54 (q) evaluation has been performed for this planned maintenance activity."

The licensee notified the NRC Resident Inspector.


* * * UPDATE FROM RICHARD COTTY TO JOHN KNOKE AT 2100 EDT ON 07/14/10 * * *

The licensee has completed the required maintenance on the TSC HVAC. The Technical Support Center is now fully functional.

The licensee will notify the NRC Resident Inspector.

PART 21 REPORT FOR CERTAIN MODEL 3051N PRESSURE TRANSMITTERS

Pursuant to 10 CFR Part 21, section 21.21 (b), Rosemount Nuclear Instruments, Inc. (RNII) is writing to inform you that a limited number of Model 3051N pressure transmitters listed in the attachment may exhibit non-linear and non-repeatable performance. The affected transmitters were shipped from RNII between August 12, 2002 and September 27,2006.

1.0 Name and address of the individual providing the information;

Mr. Marc D. Bumgarner
Vice President & General Manager
Rosemount Nuclear Instruments, Inc.
8200 Market Boulevard
Chanhassen, MN 55317

2.0 Identification of items supplied:

Certain Model 3051N pressure transmitters identified in the attachment.

3.0 Identification of firm supplying the item:

Rosemount Nuclear Instruments. Inc.
8200 Market Boulevard
Chanhassen, MN 55317

4.0 Nature of the failure and potential safety hazard;

The Model 3051N Smart Pressure Transmitter is dedicated for nuclear use consistent with the requirements of 10 CFR Part 21. It is qualified for use in safety related applications per IEEE 323-1983 (mild environment) and IEEE 344À1987 for seismic applications as documented in its associated qualification reports.

Procurement and production records indicate that 53 Model 3051N pressure transmitters (Ranges 1, 2 and 3) manufactured between August 2002 and September 2006 have sensor module castings that were not solution annealed, and therefore may contain elevated levels of hydrogen in the sensor module fill fluid. Solution annealing is a heat treatment process for castings. It is used to homogenize the casting by reducing any segregated elements that include carbon, which can greatly reduce corrosion resistance. This process also reduces the level of mobile hydrogen in the casting to a point where out gassing is no longer a reliability concern.

Elevated levels of hydrogen in the sensor module casting can create a reliability concern because mobile hydrogen can diffuse through the metal into the sensor module fill fluid and may eventually reach gas solubility limits of the fill fluid. When this occurs, gas vapor bubbles may form, primarily under vacuum process conditions, resulting in a sensor output shift. A transmitter with hydrogen bubbles in the sensor module fill fluid will annunciate
itself by exhibiting non-linear and non-repeatable performance.

To date, RNII has not received any 3051N field returns for this issue. However, there have been two confirmed failures related to this issue on a commercially available Rosemount product using the identical sensor module casting. Additionally, there have been other confirmed failures related to this issue on a commercially available Rosemount product using a similar, but not identical casting. These commercial grade product returns
prompted additional internal testing and analysis that indicated a potential reliability concern on 3051N transmitters that were manufactured with non-solution annealed module castings.

As a result, a thorough evaluation was completed and a notification about the potential substantial safety hazard identified on 7/1/10 is being made in accordance with 10 CFR Part 21 to customers that purchased a 3051N pressure transmitter from the potentially affected population.

5.0 The corrective action which is taken, the name of the individual or organization responsible for that action, and the length of time taken to complete that action:

- The last shipment of a 3051N transmitter With a non-solution annealed sensor module casting was September 2006.

- Following September 2006, all sensor module castings utilized on the 3051N have been solution annealed.

- Procurement drawings for the module castings have been reviewed and the requirement to solution anneal all module castings for a model 3051N transmitter has been verified.

- Model 3051N pressure transmitters affected by this notification may be returned to RNII for replacement at no charge.

6.0 Any advice related to the potential failure of the item:

The end user is advised to determine the impact of this potential reliability issue upon its plant's operation and safety, and take action as deemed necessary. Affected transmitters may be returned to RNII for replacement at no charge.

Rosemount Nuclear Instruments, Inc. is committed to the nuclear industry and remains dedicated to the supply of high quality products to our customers. If you have any questions, or require additional information related to this issue, please contact: Mike Dougherty (208) 865-1112, Gerard Hanson (952) 949-5233, Bob Cleveland (952) 949-5206, or Matt Doyle (952) 949-5204.

The attachment provided with this notification identified pressure transmitters delivered to the following power plants: Vermont Yankee (U.S.), Krsko (Slovenia), Santa Marie de Garona (Spain), Kuosheng Nuclear Power Station (Taiwan), and Ulchin 5 and 6 facilities (Korea).

ELECTRICAL FAULT DISABLED PUBLIC ADDRESS SYSTEM WHICH SUPPORTS VARIOUS ALARM ANNUNCIATORS

"At approximately 1200 hours (EST) on 7/12/2010, an electrical fault was identified in the fire alarm system. This fault disabled the public address portion of the system which supports annunciation of plant alarms including the following: fire alarm, criticality alarm, take-cover alarm, [carbon dioxide] discharge alarms. Trouble shooting of the problem is continuing. There is no impact to actual detection, suppression, etc. systems. Compensatory measures include the following: stop SNM handling and movement, fire patrols, restriction of hot work, notification to facility personnel, evacuation of nonessential personnel from production areas, fire brigade on standby and radios provided to fire brigade officers and some fire brigade members.

"It is believed that the condition was associated with heavy rainfall and possible water intrusion.

"There were no actual safety consequences to workers, the public, or the environment associated with the event. Potential consequences to workers, the public, or the environment are mitigated by compensatory measures."

The licensee notified the NRC Resident Inspector.

* * * UPDATE FROM RANDY SHACKELFORD TO JOHN KNOKE AT 1628 ON 7/15/10 * * *

"The public address portion of the plant alarm system was restored on 7/13/2010. It appears that recent rain storms caused some wiring to develop short circuits. These short circuits were corrected. The system is continuing to be monitored and wiring may be identified that requires replacement. It was confirmed that the criticality alarm portion of the plant alarm system was not impacted during the recent outage."

The licensee notified the NRC Resident Inspector. Notified R2 DO (Seymour), NMSS EO (Hiltz) , Fuels Grp (Email)

HPCI INADVERTENTLY ISOLATED DURING TESTING

"On 07/12/10 at 1310 CDT, while performing 2-SR-3.3.6.1.2(3B), High Pressure Coolant Injection (HPCI) System Steam Supply Low Pressure Functional Test, HPCI inadvertently isolated. The cause of isolation is unknown with an]investigation in progress. HPCI has been returned to standby readiness.

"This incident is reportable as an 8-hour ENS notification under 10CFR 50.72 (b)(3)(v) as any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. It also requires a 60 day written report.

"The NRC Resident Inspector has been notified."