05000387/LER-2005-002, TS Required Shutdown Due to Excessive Control Cell Friction
| ML060040235 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  (NPF-014) |
| Issue date: | 12/21/2005 |
| From: | Saccone R Susquehanna |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PLA-5997 LER 05-002-00 | |
| Download: ML060040235 (5) | |
| 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) 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)(x) 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 |
| 3872005002R00 - NRC Website | |
text
I R.A. Saccone PPL Susquehanna, LLC
\\ '
f Vice President-Nuclear Operations 769 Salem Boulevard s e
- a Berwick, PA 18603 Tel. 570.542.399 Fax 570.542-1504 rasaccone~pplweb.com p I.*. _
TM i)EC '21 2005 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station OPI-17 Washington, DC 20555 SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-387/2005-002-00 PLA-5997 Docket 50-387 Attached is Licensee Event Report 50-387/2005-002-00. This event was determined to be reportable per 10 CFR 50.73(a)(2)(i)(A) because the plant was shutdown as required by Technical Specification action statements.
On October 28, 2005 at 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br />, Susquehanna operators began the process of shutting down Unit 1 for a planned maintenance outage to address known control cell friction issues. Four control rods had previously been declared inoperable because of excessive rod to fuel channel friction. Other rods, previously known to exhibit slow settling characteristics, would be inserted during the controlled shutdown. Rather than delay the shutdown to perform operability testing if these rods again experienced long settling times, it was conservatively determined that any slow settling rods would be declared inoperable and that Technical Specification 3.1.3, Control Rod Operability, would be entered when nine rods had been classified as such.
As anticipated, Technical Specification 3.1.3.f was entered at 2332 hours0.027 days <br />0.648 hours <br />0.00386 weeks <br />8.87326e-4 months <br /> when the ninth control rod was declared inoperable. Entry into this specification requires that the unit be taken to Mode 3, Hot Shutdown, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The controlled shutdown continued until 0805 hours0.00932 days <br />0.224 hours <br />0.00133 weeks <br />3.063025e-4 months <br /> on October 29, 2005, when insertion of all rods was completed and Mode 3 had been entered by placing the mode switch to the Shutdown position.
There were no actual consequences to the health and safety of the public as a result of this event.
Document Control Desk PLA-5997 No new regulatory commitments have been created through issuance of this report.
4 Robert A. Saccone Vice President - Nuclear Operations Attachment cc:
Mr. S. J. Collins Regional Administrator U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19408 Mr. B. A.Bickett Sr. Resident Inspector U. S. Nuclear Regulatory Commission P.O. Box-35 Berwick, PA '18603-0035 Mr. R. Osborne Allegheny Electric Cooperative P. 0. Box 1266 Harrisburg, PA 17108-1266 Mr. R. R. Janati Bureau of Radiation Protection Rachel Carson State Office Building P. 0. Box 8469 Harrisburg, PA 17105-8469
APPROVED BY OMB: NO.315 OO104 EXPIRES: 0&30@
2007
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
LICENSEE EVENT REPORT (LER)
(See reverse for required number of digits/characters for each block)
- 1. FACILITY NAME Susquehanna Steam Electric Station - Unit 1 v DOCKET NUMBER 1
PAGE r05000387 1 OF3
- 4. TITLE TS Required Shutdown Due to Excessive Control Cell Friction
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILmES INVOLVED MONTH DAY YEAR YEAR SEQUENTRALf NO.
MONTH DAY YEAR FACILITY NAME 0C0 N
B FACILITY NAME KET NUMBER 10 28 2005 2005 002 00 12 21 2005 5000 D. OPERATING MODE 11.THS REPORT I SUBMrnlED PURSUANTTOThE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 El 20.2201 (b)
E 20.2203(a)(3)(i) 0 50.73(a)(2)(i)(C)
D 50.73(a)(2)(vii)
- 10. POWER LEVEL El 20.2201(d) 0 20.2203(a)(3)(ii)
E 50.73(a)(2)(ii)(A) a 50.73(a)(2)(viiW)(A) 0 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B) 1Q8 El 20.2203(a)(2)(1)
D 50.36(c)(1)(i)(A)
D 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A) 0I 20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(lv)(A)
E 50.73(a)(2)(x) 0I 20.2203(a)(2)(li) 0 50.36(c)(2)
El 50.73(a)(2)(v)(A) 0 73.71 (a)(4)
El 20.2203(a)(2)(Iv) 0 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B) 0 73.71(a)(5) 0 20.2203(a)(2)(v) 10 50-73(a)(2)(i)(A)
O 50.73(a)(2)(v)(C) 0 OTHER 0 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B) a 50.73(a)(2)(v)(D)
Specify in Abstract below or in NRC Forrn 366A
- 12. LICENSEE CONTACT FOR THIS LER FACIEDY NAME InLEHONE NUMER (hide Area Coda)
Eric J. Miller - Nuclear Regulatory Affairs 570-542-3321
- 14. SUPPLEMENTAL REPORT EXPECTED D YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
ED NO kBSTRACT (LUn to 400spaces, ie., sppiidmtely 5 singe-spaed wewrten fines) i On October 28, 2005 at 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br />, Susquehanna operators began the process of shutting down Unit 1 for a planned maintenance outage to address known control cell friction issues. The cell friction issues had manifested during Unit I's 14h fuel cycle when multiple control rods failed to settle into their targeted latched position. At the time of the shutdown, four control rods had been declared inoperable because of excessive rod to fuel channel friction. Other rods, previously known to exhibit slow settling characteristics, would be inserted during the controlled shutdown. It was conservatively determined that any control rods experiencing long settling times would be declared inoperable so that the shutdown would not be slowed by additional testing necessary to prove operability. Technical Specification 3 1.3, Control Rod Operability, would be entered when nine rods had been declared inoperable. Entry into TS 3.1.3.f requires that the unit be taken to Mode 3, Hot Shutdown, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. At the time the ninth control rod was declared inoperable at 2332 hours0.027 days <br />0.648 hours <br />0.00386 weeks <br />8.87326e-4 months <br /> on October 28, Unit 1 had already been reduced to 18% power. The controlled shutdown continued until 0805 hours0.00932 days <br />0.224 hours <br />0.00133 weeks <br />3.063025e-4 months <br /> on October 29, 2005 when insertion of all rods was completed and Mode 3 had been entered by placing the mode switch to the Shutdown position. Entry into the shutdown TS occurred because of a decision strategy that emphasized timely shutdown progress. Additional operability testing, if performed, would have likely precluded any need to enter the TS.
With no substantive benefit attainable from such testing, the strategy was sound.
Even though the plant shutdown was planned and in-progress, the shutdown became a Technical Specification mandate at 2332 hours0.027 days <br />0.648 hours <br />0.00386 weeks <br />8.87326e-4 months <br /> on October 28 when the ninth control rod was declared inoperable. Accordingly, this event is being reported as a Tech Spec required shutdown per 10 CFR 50.73(a)(2)(i)(A). There were no safety consequences or compromises to public health and safety as a result of this event.
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(ffp space i sreqred, eaddtonal copes NRC Fb 023664)
EVENT DESCRIPTION
On October 28, 2005 at 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br />, Susquehanna operators (Licensed, Utility) began the process of shutting down Unit 1 for a planned maintenance outage to address known control cell (EIIS Code: AC) friction issues. The cell friction issues had manifested during Unit l's leth fuel cycle when multiple control rods (EIIS Code: JD) failed to settle into their targeted latched position within 30 seconds. At the time of the shutdown, four control rods had been declared inoperable because of excessive rod to fuel channel friction. Other rods, previously known to exhibit slow settling characteristics, would be inserted during the controlled shutdown. Although previous test data obtained during the operating cycle suggested that majority of those control rods expected to exhibit slow settling would have passed operability testing, it was conservatively determined that any such rod would be declared inoperable so that the shutdown would not be slowed by additional testing necessary to prove operability. Technical Specification (TS) 3.1.3, Control Rod Operability, would be entered when nine rods had been declared inoperable.
As anticipated, TS 3.1.3.f was entered at 2332 hours0.027 days <br />0.648 hours <br />0.00386 weeks <br />8.87326e-4 months <br /> when the ninth control rod was declared inoperable. (Note: Entry into this specification was also satisfied shortly thereafter because four-control rods residing within one Banked Position Withdrawal Sequence group were declared inoperable.) Entry into TS 3.1.3.f requires that the unit be taken to Mode 3, Hot Shutdown, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. At the time the ninth control rod was declared inoperable, Unit 1 had already been reduced to 18% power. The controlled shutdown continued until 0805 hours0.00932 days <br />0.224 hours <br />0.00133 weeks <br />3.063025e-4 months <br /> on October 29, 2005 when insertion of all rods was completed and Mode 3 had been entered by placing the mode switch to the Shutdown position.
There were no Emergency Core Cooling System (EIIS Code: B) initiatiorns and no challenges 'to containment (EIIS Code:
NH) experienced during the shutdown.
Even though the plant shutdown was planned and in-progress, the shutdown became a Technical Specification mandate at 2332 hours0.027 days <br />0.648 hours <br />0.00386 weeks <br />8.87326e-4 months <br /> on October 28 when the ninth control rod was declared inoperable. Accordingly, this event is being reported as a Tech Spec required shutdown per 10 CFR 50.73(a)(2)(i)(A).
CAUSE OF EVENT
Entry into the shutdown TS was the result of a station strategy that emphasized timely shutdown progress. This strategy recognized the need to enter TS 3.1.3.f. Entry into the Limiting Condition of Operation (LCO) did not impact the course of the shutdown in any way. Entry into TS 3.1.3.f was readily avoidable via manual RPS (EIIS Code: JC) initiation before LCO control rod operability limits were threatened. Such action would have, however, defeated information gathering objectives of the controlled shutdown. It is believed that the subject control rods would have likely passed operability testing if initiated.
ANALYSIS / SAFETY SIGNIFICANCE There was no significance to the administrative entry to TS 3.1.3.f. The control rod drive system (EIIS Code: AA) remained fully capable of performing its function throughout the shutdown. Efforts to perform operability testing, testing that would have likely avoided TS entry, would have slowed progress on a controlled shutdown that was already taking place.
(If amo spce is requred, use acktonal copies of NRC Fom 366A)
CORRECTIVE ACTIONS
None required. Entry into the shutdown Technical Specification was the result of a non-impacting shutdown decision strategy.
ADDIONAL INFORMATION An extensive fuel re-channeling effort was completed during the shutdown to address control cell friction issues. Cell friction, although not directly responsible for entry into the TS required shutdown LCO, was the primary initiator of the planned maintenance outage. The cell friction issue continues to be explored in Susquehanna's corrective action program.