05000498/LER-2010-001, Unit Shutdown Required by Technical Specifications
| ML101020058 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 04/05/2010 |
| From: | Peter L South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-10002544 LER 10-001-00 | |
| Download: ML101020058 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4982010001R00 - NRC Website | |
text
Nuclear Operating Company South Tews Proect Electnc Generaftng Station P. Box 289 Wadsworth Texas 77483 J.....--
April 5, 2010 NOC-AE-1 0002544 File No.: G25 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 South Texas Project Unit 1 Docket No. STN 50-498 Licensee Event Report 1-2010-001 Unit Shutdown Required by Technical Specifications Pursuant to 10 CFR 50.73, STP Nuclear Operating Company (STPNOC) submits the attached Unit 1 Licensee Event Report 1-2010-001 regarding a plant shutdown required by Technical Specifications as a result of more than one control rod inoperable but trippable. This condition is reportable under 10 CFR 50.73(a)(2)(i)(A).
This event did not have an adverse effect on the health and safety of the public.
There are no commitments contained in this Licensee Event Report. Corrective actions will be processed in accordance with the STP Corrective Action Program.
If there are any questions on this submittal, please contact either J. R. Morris at (361) 972-8652 or me at (361) 972-7158.
LW.Peter Plant General Manager JRM Attachment: LER 1-2010-001, Unit Shutdown Required by Technical Specifications STI: 32644644
NOC-AE-1 0002544 Page 2 of 2 cc:
(paper copy)
(electronic copy)
Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 612 East Lamar Blvd., Suite 400 Arlington, Texas 76011-8064 Mohan C. Thadani Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 8B 1A) 11555 Rockville Pike, Rockville, MD 20852 Senior Resident Inspector U. S. Nuclear Regulatory Commission P.O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704.
Kevin Howell Catherine Callaway Jim von Suskil NRG South Texas LP A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP Mohan Thadani U. S. Nuclear Regulatory Commission J. J. Nesrsta R. K. Temple Kevin Polio E. Alarcon City Public Service C. Mele City of Austin Jon C. Wood Cox Smith Matthews Richard A. Ratliff Texas Department of Health Services Alice Rogers Texas Department of Health Services
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010
- 9-2007)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE South Texas Unit 1 05000498 1 OF 5
- 4. TITLE Unit Shutdown Required by Technical Specifications
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO.
MONTH DAY YEAR N/A N/A FACILITY NAME DOCKET NUMBER 02 03 2010 2010 - 001 0
04 05 2010 N/A N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
[] 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii).
1 [J 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
[I 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
[I 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL [l 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
[I 50.73(a)(2)(iv)(A)
El 50.7,3(a)(2)(x)
[E 20.2203(a)(2)(iii)
El 50.36(c)(2) 0l 50.73(a)(2)(v)(A)
El 73.71(a)(4)
[J 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100%
[E 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A)
[] 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
El 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below
- 12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (Include Area Code)
James R. Morris, Licensing Engineer 361-972-8652CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX NA
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR SUBMISSION [E YES (If yes, complete 15. EXPECTED SUBMISSION DATE) x NO DATE iBSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On February 3, 2010, with Unit 1 at 100% power, monthly shutdown and control rod testing was being performed. Previously on January 6, 2010, control rod C-5 had been determined to be inoperable, but trippable. During testing on February 3, a second control rod (B-12) was determined to be inoperable, but trippable. Attempts to realign the control rod with its bank were unsuccessful. Consequently, TS 3.0.3 was entered and the Unit was shutdown to Mode 3.
This event is reportable per 10 CFR 50.73(a)(2)(i)(A), "The completion of any nuclear plant shutdown required by the plant's Technical Specifications."
The cause of this event was insufficient removal and dispersion of the.corrosion products originating from the normal fabrication and passivation process of the new CRDM latch assemblies associated with the Unit 1 Replacement Reactor Vessel Head.
All shutdown and control rods remained fully trippable during this event. There were no personnel injuries, no offsite radiological releases, and no damage to other safety-related equipment.
NRC FORM 366 (9-2007)
(If more space is required, use additional copies of SUMMARY OF THE EVENT On January 6, 2010, Unit 1 conducted monthly shutdown and control rod surveillance testing at 100% power. When Shutdown Bank D was inserted and withdrawn, Shutdown Bank D rod C-5 did not withdraw. Attempts to realign rod C-5 were unsuccessful and reactor power was reduced to less than 75% to comply with Technical Specification (TS) 3.1.3.1 actions.
Rod C-5 remained trippable.
On January 14, 2010, Unit 1 conducted shutdown and control rod surveillance testing at approximately 74% power with the full out position set at 259 steps for the remainder of the rods not tested on January 6 (Shutdown Bank E and Control Banks A, B, C, and D). No rod misstepping or rod position anomalies were noted for these rod banks.
On January 19, 2010, with Unit 1 operating in Mode 1 at approximately 75% power, the full out position of all Unit 1 rods was changed to 249 steps in accordapce with a revision to the Core Operating Limits Report and per plant procedure. The shutdown and control banks were inserted to 249 steps. This allowed Unit 1 to be returned to full power operations, since the inoperable rod was now within 12 steps of its group demand position, as required by TS 3.1.3.1.
On February 3, 2010, Unit 1 again conducted monthly shutdown and control rod surveillance testing at 100% power. When Shutdown Bank A was inserted and withdrawn, rod B-12 did not withdraw when demanded. The Operating crew entered TS 3.1.3.1 action c (for more than one rod inoperable but trippable), but attempts to realign rod B-1 2 with its bank were unsuccessful. Subsequently, TS 3.0.3 was entered and the unit was shutdown to Mode 3.
(If more space is required, use additional copies of (if more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
IV. CORRECTIVE ACTIONS
Prior to Unit 1 restart, each shutdown and control rod was moved through its full length of travel multiple times, including 10 rod drops from the full out position.
Shutdown and control rod exercising is being performed on a more frequent basis until sufficient performances indicate that passivation has been achieved such that rod misstepping is resolved.
V. PREVIOUS SIMILAR EVENTS
On January 5, 2006, Unit 2 control rod D-4 misaligned by approximately 7 steps. The rod was declared inoperable but trippable and TS 3.1.3.1 Action b.2 was entered. The grippers were exercised (no rod motion) and the control rod was successfully realigned with its bank. The monthly shutdown and control rod surveillance test was then performed satisfactorily as a post-maintenance test.
VI. ADDITIONAL INFORMATION
None.