ML13262A094
| ML13262A094 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 09/05/2013 |
| From: | Marc-Anthony Murray South Texas |
| To: | Mark Lombard Document Control Desk, NRC/NMSS/SFST |
| References | |
| NOC-AE-13003030 | |
| Download: ML13262A094 (6) | |
Text
Nuclear Operating Company South Texas Project Electric Generating Station PO. Box 289 Wadsworth, Texas 77483
/
September 5, 2013 NOC-AE-13003030 10 CFR 71.95 (a)(3)
Mark Lombard Director, Division of Spent Fuel Storage and Transportation Office of Nuclear Material Safety and Safeguards U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Unit I & 2 Docket Nos. STN 50-498, STN 50-499 10 CFR 71.95 Report on Non-Compliance with Conditions of Approval in the Certificate of Compliance for 8-120B Casks
Reference:
EnergySolutions Letter, Daniel B. Shrum to NRC, Mark Lombard, "10 CFR 71.95 Report on the 8-1208 Cask," dated August 14, 2013 (CD13-0232)
STP Nuclear Operating Company (STPNOC) submits the attached report providing the information required by 10 CFR 71.95 (a) (3) for instances in which the conditions of approval in the Certificate of Compliance for the 8-120B Cask (Certificate of Compliance #9168) were not observed in making certain shipments. On August 11,. 2013, STPNOC was notified by EnergySolutions of the potential issue identified in the referenced letter. STPNOC determined that several shipments in the past used 8-120B Casks which were not appropriately leak tested.
There are no regulatory commitments in this letter.
If there are any questions regarding this report, please contact Robyn Savage at 361-972-7438.
Michael P P y
- Manager, egulatory Affairs
Attachment:
Non-Compliance with Certificate of Compliance Conditions for 8-120B Cask Vent Port Leak Testing rds STI: 337442720,ot"
NOC-AE-13003030 Page 2 cc:
(paper copy)
(electronic copy)
Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 76011-4511 Balwant K. Singal Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 8 B1) 11555 Rockville Pike Rockville, MD 20852 NRC Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 Jim Collins Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 Dan Shrum Senior Vice President, Regulatory Affairs EnergySolutions 423 West 300 South, Suite 200 Salt Lake City, UT 84101 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP Balwant K. Singal U. S. Nuclear Regulatory Commission John Ragan Chris O'Hara Jim von Suskil NRG South Texas LP Kevin Polio Richard Pefia City Public Service Peter Nemeth Crain Caton & James, P.C.
C. Mele City of Austin Richard A. Ratliff Texas Department of State Health Services Robert Free Texas Department of State Health Services
Attachment NOC-AE-13003030 Page 1 of 4 Non-Compliance with Certificate of Compliance Conditions for 8-120B Cask Vent Port Leak Testing
- 1. Abstract This report provides the information required by 10 CFR 71.95 (a) (3) for two instances in which the conditions of approval in the Certificate of Compliance (CoC) for the 8-120B cask (Certificate of Compliance #9168) were not observed for radioactive waste shipments from the South Texas Project (STP). In addition, the report includes details on two instances where the conditions of the CoC for shipment of 8-120B casks were likely not met.
EnergySolutions air pressure drop test procedure describes a 20 minute hold time for the pre-shipment leak test of the cask vent port. Their 8-120B Safety Analysis Report (SAR),
specifies a hold time of 60 minutes for the leak test of the vent port; therefore the conditions of approval in the CoC were not observed in making four shipments. EnergySolutions now require new lids to be used on the 8-120B casks after August 31, 2013, using different testing procedures that are authorized in the latest revision of the CoC. Should the 8-120B casks be used in the future, STP Nuclear Operating Company (STPNOC) will use the current revision of EnergySolutions procedure to perform the leak tests.
- 2. Narrative Description of the Event EnergySolutions air pressure drop test procedure TR-TP-002 is the basis for leak tests on all EnergySolutions shipments, as well as the suggested procedure content for most shipments by EnergySolutions authorized users. The 8-120B CoC requires the package to be prepared for shipment and operated in accordance with Chapter 7 of the 8-120B SAR, and tested and maintained in accordance with Chapter 8 of the 8-120B SAR. TR-TP-002 captures the applicable 8-120B SAR requirements and provides further detail for shipper's operating procedures. Recently, an 8-120B cask user identified the hold time discrepancy between TR-TP-002 and the 8-120B SAR (i.e., 20 versus 60 minutes). Based on EnergySolutions review, it appears that this discrepancy has existed for approximately 12 years.
Upon notification and after confirmation of the discrepancy, STPNOC determined there were four shipments using the 8-120B cask. The 8-120B SAR requires pre-shipment leak testing of the vent port only when the port has been opened since the preceding vent port leak test.
STPNOC found that the test procedure for the vent port was performed using the 20 minute hold time for two of the four shipments. No vent port test was performed for the other two instances; however, since other licensees would also use the test procedure TR-TP-002, it is likely that the leak test that was performed prior to the STP shipments did not use the 60 minute hold time.
In EnergySolutions report required by 10 CFR 71.95 dated August 14, 2013, related to this subject, they noted that the licensing basis for the pre-shipment leak tests for all three of the 8-120B lid containment seals is a pressure drop calculation for the largest of the three seals (the primary lid seal). The required hold time is therefore conservative for the two seals with smaller test volumes. Because of the small size of the vent port seal test volume, EnergySolutions has determined that the 20 minute hold time meets the same criterion by which the 60 minute hold time was derived for the larger primary lid seal. In the case of the
Attachment NOC-AE-13003030 Page 2 of 4 vent port leak test, the 20 minute hold time provides substantial margin for detecting any leakage from the vent port. It therefore follows that there is no safety significance associated with these issues.
STPNOC has not used the 8-120B casks for shipments since 2008. EnergySolutions now requires that new lids be used on the 8-120B casks after August 31, 2013, using different testing procedures that are authorized in the latest revision of the CoC. Should the 8-120B casks be used in the future, STPNOC will use the current revision of EnergySolutions procedure that incorporates the required leak testing in accordance with the latest CoC. No further corrective actions are necessary to address this issue.
(i)
Status of Components STP has no 8-120B casks onsite.
(ii)
Dates of Occurrence The following shipments were made from the South Texas Project to the Barnwell Waste Management Facility used 8-120B casks:
STP-1-01-0077 shipped on 12-06-2001 (No vent port test performed)
STP 2-04-0043 shipped on 11-04-2004 (No vent port test performed)
STP-1-07-0008 shipped on 06-07-2007 (Vent port test used 20 minute hold time)
STP-2-08-010 shipped on 03-13-2008 (Vent port test used 20 minute hold time)
(iii)
Cause of Error Discrepancy between EnergySolutions air pressure drop test procedure TR-TP -002 and Chapter 8 of the 8-120B SAR.
(iv)
Failure Mode, Mechanism, and Effects Not applicable; no 8-120B packaging components failed.
(v)
Systems or Secondary Functions Affected Not applicable (vi)
Method of Discovery of the Error The condition was identified by an 8-120B cask user. EnergySolutions, subsequently notified STP Nuclear Operating Company of the issue on August 11, 2013.
(vii)
For each human performance-related root cause, a discussion of the causes and circumstances Reference EnergySolutions letter to the NRC from Daniel B. Shrum entitled "10 CFR
Attachment NOC-AE-13003030 Page 3 of 4 71.95 Report on the 8-120B Cask," dated August 14, 2013 (CD13-0232).
(viii)
Manufacturer and model number (or identification) of Each Component STP-1-01-0077 shipped cask serial number 8-120B-2S on 12-06-2001 STP 2-04-0043 shipped cask serial number 8-120B-1 on 11-04-2004 STP-1-07-0008 shipped cask serial number 8-120B-2 on 06-07-2007 STP-2-08-010 shipped cask serial number 8-12OB-2S on 03-13-2008 (ix)
Quantities and Chemical and Physical form(s) of the Package Contents STP-1-01-0077 shipment containing 133 Curies total activity consisting of dewatered mechanical filters - Solid/Metal Oxides with the following radionuclides present: C-14, Mn-54, Fe-59, Co-58, Ni-63, Zr-95, Nb-95, Sn-113, Sb-1 25, Ce-144, Pu-239, Am-241, Cm-243, Cr-51, Fe-55, Co-57, Co-60, Zn-65, Nb-94, Ag-110m, Sb-124, Cs-137, Pu-238, Pu-241, Cm-242, Tc-99 LLD, H-3 LLD, 1-129 LLD STP 2-04-0043 shipment containing 198 Curies total activity consisting of dewatered mechanical filters - Solid/Metal Oxides with the following radionuclides present: Cr-51, Fe-55, Co-57, Co-60, Zn-65, Nb-94, Ag-11im, Sb-124, Cs-137, Pu-238, Pu-241, Cm-242, Mn-54, Fe-59, Co-58, Ni-63, Zr-95, Nb-95, Sn-113, Sb-1 25, Ce-144, Pu-239, Am-241, Cm-243, 1-3 LLD, Tc-99 LLD, C-14 LLD, 1-129 LLD STP-1-07-0008 shipment containing 173 Curies total activity consisting of dewatered mechanical filters - Solid/Metal Oxides with the following radionuclides present: C14, Mn-54, Fe-59, Co-58, Ni-63, Nb-95, Sb-125, Cs-137, Cr-51, Fe-55, Co-57, Co-60, Zr-95, Ag-11im, Cs-134, Ce-144, Tc-99 LLD, H-3 LLD, 1-129 LLD STP-2-08-010 shipment containing 114 Curies total activity consisting of dewatered mechanical filters - Solid/Metal Oxides with the following radionuclides present: H-3, Fe-55, Co-58, Zn-65, Ag-11im, Cs-134, Pu-238, Pu-241, Cr-51, Fe-59, Co-60, Zr-95, Sn-113, Cs-137, Pu-239, Pu-242, Mn-54, Co-57, Ni-63, Nb-95, Sb-125, Ce-144, Pu-240, Am-241, Tc-99 LLD, C-14 LLD, 1-129 LLD
- 3. Assessment of Safety Consequences There is no safety consequence of performing the pre-shipment leak test for the 8-120B cask vent port using a 20 minute hold time versus the 60 minute hold time that is required by the 8-120B cask CoC. The required hold time varies in proportion to the test volume if the test pressure and acceptance criterion remain unchanged. Larger test volumes require longer hold times. The test volume includes the free volume of the space to be tested and the volume of the test manifold. For the original subject 8-120B lids, Section 4.4 of the July 2012 SAR Addendum shows the calculation basis for a 60 minute hold time. Only one calculation was presented for the large primary lid containment seal. Since the other seals have smaller test volumes, a 60 minute hold time was conservatively specified for all seals, including the vent port.
Attachment NOC-AE-13003030 Page 4 of 4 The SAR test volume for the primary containment seal was 103.2 cc. For the pre-shipment vent port leak test, there is no safety impact from a 20 minute hold time provided that the test volume is less than or equal to the 20/60 times the primary containment seal test chamber volume, or (20/60)* 103.2 = 34.4 cc. The vent port test volume is equal to the combined volume of the test manifold (10 cc) plus a very small residual volume inside the vent port, which is less than 34.4 cc. Therefore, pre-shipment leak tests of the vent port performed using a 20 minute hold time are adequate to demonstrate compliance with maximum leak rate acceptance criteria, and there is no safety consequence from testing vent ports for 20 minutes instead of 60 minutes.
- 4. Planned Corrective Actions STPNOC has not used the 8-120B casks for shipments since 2008. Should the 8-120B casks be used in the future, STPNOC will use the current revision of EnergySolutions procedure that incorporates the required leak testing in accordance with the latest CoC. No further corrective actions are necessary to address this issue.
- 5. Previous Similar Events Involving the 8-120B Cask No previous similar events have been identified.
- 6. Contact for Additional Information Robyn Savage STPNOC Licensing 361-972-7438
- 7. Extent of Exposure of Individuals to Radiation or Radioactive Materials None