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Industry SNM Operating Experience. Tom Morello and Nicole Walker Constellation Energy. Overview. Introduction SNM Operating Experience Cause Compliance Conclusion. Incore Detector Containing Special Nuclear Material Inappropriately Released From Storage (OE24386). February 12, 2007
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Industry SNM Operating Experience Tom Morello and Nicole Walker Constellation Energy
Overview Introduction SNM Operating Experience Cause Compliance Conclusion
Incore Detector Containing Special Nuclear Material Inappropriately Released From Storage (OE24386) • February 12, 2007 • Event: • Maintenance removed an incore detector from its storage location without prior notification to Radiation Protection. • The incore detector contained SNM, but there were no labels signifying this on the detector storage area. • The area housing the detector was controlled with a Radiation Protection key.
Incore Detector Containing Special Nuclear Material Inappropriately Released From Storage (OE24386) • Event Continued: • Assumed that detector was not under RWP control (not labeled SNM) • Causes: • SNM storage areas not labeled, but required by procedure • The supervisor of storeroom maintained a key which RP should have had instead
Incore Detector Containing Special Nuclear Material Inappropriately Released From Storage (OE24386) • Ensuring Compliance: • Label SNM storage areas • Train personnel about SNM storage and accountability (Radiation Protection, Security, etc) • Ensure SNM is stored separately from other non-SNM materials
Inadequte Control of Special Nuclear Material Located Outside Protected Area (OE29504) • December 6, 2008 • Event: • An intermediate range nuclear instrument detector was found in a storage area outside the plant’s Protected Area, but within the Owner Controlled Area. • The detector contained about 7.12 g of U-235 • The SNM custodian understood SNM requirements: • Stored in a locked, radiologically-controlled area
Inadequte Control of Special Nuclear Material Located Outside Protected Area (OE29504) • Event Continued: • SNM custodian unaware SNM required by procedure to be in Protected Area (PA) • Security review of procedures in 2009 led to discovery of the source’s location • The SNM was relocated inside the PA and tamper-indicating tape was placed on container • Cause: • Procedure for SNM Control- inadequate
Inadequte Control of Special Nuclear Material Located Outside Protected Area (OE29504) • Ensuring Compliance: • Correct procedure use • Procedure should only allow storage of SNM in ICA’s in the protected area
Loss of Accountability of Less Than 1 Gram of SNM (OE24760) • April 4, 2007 • Event: • In 1990, an assembly was disassembled for rod inspections • One of the rods was confirmed failed, but bent and snapped while in fuel inspection funnel. • A bucket placed under the broken fuel rod segments contained small dark particles and a small piece of material
Loss of Accountability of Less Than 1 Gram of SNM (OE24760) • Event Continued: • The small piece of material was suspected to be less than 10% of a single pellet’s worth (less than 1 gram). • Greater than 400 Rad/hr on contact- most likely a piece of fuel pellet • The bucket and its contents were hung on a wall in the Spent Fuel Pool
Loss of Accountability of Less Than 1 Gram of SNM (OE24760) • Event Continued: • The next refueling outage, the bucket was knocked into the pool resulting in a loss of control of licensed material. • This was reportable under 10CFR20.2201 • Causes: • Not understanding the requirements for tracking less than 1 gram of SNM
Loss of Accountability of Less Than 1 Gram of SNM (OE24760) • Ensuring Compliance: • Understand reporting requirements for all SNM • Do not use an open container, like a bucket, to store SNM
Reportable Quantity of SNM Was Not Being Reported (OE29634) • August 4, 2009 • Event: • Audit showed the Plutonium-Beryllium(PuBe) source was not being reported on the annual NRC form 742. • The source had material type 83 (Pu-238). • The source contained 0.33 g of Pu-238. Type 83 material should have been tracked to the nearest 0.1g (NuReg/BR-0007)
Reportable Quantity of SNM Was Not Being Reported (OE29634) • Event Continued: • There was no form 741 because there was less than 1.0 g of SNM. • Radiation Protection manuals processed the receipt of the source; documentation is limited • The source was tracked and verified semiannually. • A form 741 will be generated, and the source will be added to the yearly Material Balance Report.
Reportable Quantity of SNM Was Not Being Reported (OE29634) • Cause: • Lack of understanding of tracking and reporting of requirements of material type 83. • Ensuring Compliance: • Report type 83 material to nearest 0.1g. • Ensure understanding of material types in any sources on site.
Special Nuclear Material Reporting Requirements Not Met on Reactor Vessel Head (OE25343) • June 19, 2009 • Event: • Comanche Peak agreed to notify NMMSS within 30 days of plant start up of it’s new Japanese reactor vessel head. • Because part of the vessel head was made in Japan, CPNPP had new SNM tracking requirements. • After 59 days of operation, there was still no report on the change in obligations.
Special Nuclear Material Reporting Requirements Not Met on Reactor Vessel Head (OE25343) • Event Continued: • CPNPP also discovered errors in their obligation codes for the fuel that was in the core. • Upon agreement between NMMSS, Reg Affairs, and the NRC, CPNPP had to submit the corrections from the fuel receipt, and then submit the Japanese obligation. • Causes: • Errors in tracking and documenting SNM
Special Nuclear Material Reporting Requirements Not Met on Reactor Vessel Head (OE25343) • Ensuring Compliance: • Report head obligation material in accordance with the agreement with the NRC.
Plutonium and U234/U235 Sources Not Tracked by the SNM Program (OE24419) • February 2, 2007 • Event: • Radiation Protection asked to identify any non-fuel SNM. • Discovered 14 electroplated Pu-239 disk sources and 6 U234/U235 sources • RP procedures require inventory every 3 months, so the detectors were accounted for and controlled as licensed material
Plutonium and U234/U235 Sources Not Tracked by the SNM Program (OE24419) • Event Continued: • The sources were never part of the SNM inventory (already inventoried by RP procedures) • All non-fuel SNM are required to be included in the SNM inventory • Causes: • Lack of understanding of the SNM reporting requirements for non-fuel SNM.
Plutonium and U234/U235 Sources Not Tracked by the SNM Program (OE24419) • Ensuring Compliance: • Update procedures to include any sources (even ones owned by RP) in the SNM physical inventory. • Incorporate RP so that they report SNM inventory to the SNM custodian. • Track check sources (either SNM custodian or RP)
Special Nuclear Material Inventory Error (OE24314) • February 6, 2007 • Event: • Failed source range monitors, intermediate range monitors, and TIP detectors were stored in a designated location in Radwaste Building • In November 2000, a non-irradiating traversing in-core probe (TIP) was documented as being in storage drum 471 with tamper proof seal.
Special Nuclear Material Inventory Error (OE24314) • Event continued: • A source range monitor (SRM) documented to be in a drum numbered 742 with tamper proof seal. • Storage drum 742 was shipped off-site. • Reactor engineering was performing inventory and noticed that the TIP detector was not in its specified location in the SNM Inventory Account. • A radioactive material bag labeled “TIP cables” was found in drum 471, instead.
Special Nuclear Material Inventory Error (OE24314) • Event Continued: • The tamper proof seal on drum 741 was not breached from 2000-2007. • A radioactive material bag labeled SRM cable had an SRM. The SRM was not included in the annual inventory. • Cause: • Site personnel relied on the description and date of the RAM tag to identify the contents.
Special Nuclear Material Inventory Error (OE24314) • Ensuring Compliance: • Follow procedures and SNM inventory requirements • Update procedures to label/tag storage areas better. • Do not rely on tags/labels
Tamper Indicating Devices on Detector Storage Containers Inadequate (OE25059) • June 14, 2007 • Event: • An NRC Material Control and Accountability Audit performed. • Locks on storage areas for fission chambers not adequate. • A controlled key is not an acceptable substitute even though site personnel argued the locks would have to be physically broken for an unapproved access.
Tamper Indicating Devices on Detector Storage Containers Inadequate (OE25059) • Ensuring Compliance: • Install tamper evident devices on storage containers used to store non-exempt detectors • Perform a piece count of the detectors.
Special Nuclear Material Movement Authorization Sheet did not Specify Correct Location for Fuel Assembly in SFP During MPC Loading (OE29837) • June 25, 2009 • Event: • After first ISFSI campaign, there were supplemental moves that needed to be done before the 2nd loading. • The supplemental moves were not completed until a week later, so only the first ISFSI loading move sheets were updated in the fuel accountability database.
Special Nuclear Material Movement Authorization Sheet did not Specify Correct Location for Fuel Assembly in SFP During MPC Loading (OE29837) • Event continued: • The second cask loading move sheets were issued without first completing the supplemental moves. • The supplemental moves were completed that same day, as was the database. • During the 2nd cask loading, the fuel handling supervisor noticed that there was not an assembly in the location specified by the move sheet. • Work stopped until the issue was resolved.
Special Nuclear Material Movement Authorization Sheet did not Specify Correct Location for Fuel Assembly in SFP During MPC Loading (OE29837) • Event Continued: • The SFP map was accurate, not the move sheets for the 2nd cask loading. • Cause: • Move sheets were made before the previous set of move sheets were retrieved and used to update the fuel accountability database.
Special Nuclear Material Movement Authorization Sheet did not Specify Correct Location for Fuel Assembly in SFP During MPC Loading (OE29837) • Ensuring Compliance: • Procedures should allow only one set of move sheets at a time (except for core alterations) • Update database before planning more moves. • Require that all move sheets be returned to the SNM custodian at the end of shift for database updates (except for core alterations) • Use a database or procedure that ensures plant configurations are up to date.
Special Nuclear Material Inventory Discrepancy (OE29563) • July 22, 2009 • Event: • A SFP cleanup campaign held in February 2005. It staged detectors into a shipping cask for disposal. No LPRM canisters were shipped offsite. • An unirradiated local power range monitor detector was expected to be stored in a canister in a SFP drum. • The detector continued to be on the SNM inventory
Special Nuclear Material Inventory Discrepancy (OE29563) • Event continued: • The detector could not be located during an SNM inventory. • SNM Tracking Sheet STS-1-14-21 showed the detector being shipped to Barnwell, SC in February 2005. • Causes: • Assuming the detector was stored in the detector canister.
Special Nuclear Material Inventory Discrepancy (OE29563) • Ensuring Compliance: • Adhere to procedure to properly store SNM in identifiable containers.