Palo Verde provides the following response: Palo Verde uses 4 different types of tungsten electrodes:
Lanthanated Ceriated Tri Mix tungsten and Pure tungsten . Because the thoriated tungsten electrodes release radioactivity we replaced these around 2-3 years ago. The thoriated electrodes used to set off the tool monitors at times but the newer electrodes do not. Palo Verde uses the other types of tungsten rods listed above depending on the application, e.g., pure tungsten is used to weld aluminum. ********************************************************************** Seth J. Kanter, CHP, RPT Sr. Health Physicist Palo Verde Nuclear Generating Station Mail Sta. 7397 5801 S. Wintersburg Rd. Tonopah, AZ 85354 Phone (623) 393-3130 Fax (623) 393-2487 Unless otherwise noted, all opinions are my own Liviu Librescu ********************************************************************** From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, November 16, 2010 9:50 AM To: [email protected] Subject: Powernet: WELD ROD TH232 CONTRIBUTES TO DETECTABLE ALPHA- DOES YOUR SITE USE LANTHANUM RODS? LaSalle is requesting the following information: 1. Does your site use lanthanum rods for welding? 1. Any other information such as site contact, application, etc., if available. Background; We had some Th-232 alpha issues in our spring outage related to grinding weld rod/tips. Out of that came the following action; RP to benchmark industry to see if other stations use lanthanum weld rod (lanthanum rods do not contain natural alpha emitter isotopes but provide as good a weld). From benchmark, determine if such rods should be considered for use at LaSalle. These type of rods are much more expensive than the regular weld rods. Thanks, EdWolfe ExelonNuclear LaSalleStation SeniorALARA Analyst *Telephone:815.415.2521 *Email:[email protected] *Fax: 815.415.4018 On-sitepager: 815.415.2521 Off-sitepager: 815.983.0811 ************************************************** This e-mail and any of its attachments may contain Exelon Corporation proprietary information, which is privileged, confidential, or subject to copyright belonging to the Exelon Corporation family of Companies. This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout. Thank You. ************************************************** Email Firewall made the following annotations --------------------------------------------------------------------- --- NOTICE --- This message is for the designated recipient only and may contain confidential, privileged or proprietary information. If you have received it in error, please notify the sender immediately and delete the original and any copy or printout. Unintended recipients are prohibited from making any other use of this e-mail. Although we have taken reasonable precautions to ensure no viruses are present in this e-mail, we accept no liability for any loss or damage arising from the use of this e-mail or attachments, or for any delay or errors or omissions in the contents which result from e-mail transmission. ---------------------------------------------------------------------
