05000220/LER-2005-002, Re Fuel Moved with an Inoperable Source Range Monitor Due to Human Error Resulting in a Technical Specification Violation
| ML051720401 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 06/13/2005 |
| From: | O'Connor T Niagara Mohawk Power Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NMP1L 1957 LER 05-002-00 | |
| Download: ML051720401 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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)(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)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2) |
| 2202005002R00 - NRC Website | |
text
Constellation Energye A Nine Mile Point Nuclear Station P.O. Box 63 Lycoming,NY 13093 June 13, 2005 NMP1L 1957 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Nine Mile Point Unit 1 Docket No. 50-220 Facility Operating License No. DPR-63 Licensee Event Report 05-002, "Fuel Moved with an Inoperable Source Range Monitor Due to Human Error Resulting in a Technical Specification Violation" Gentlemen:
In accordance with 10 CFR 50.73(a)(2)(i)(B), Nine Mile Point Nuclear Station, LLC hereby submits Licensee Event Report 05-002, "Fuel Moved with an Inoperable Source Range Monitor Due to Human Error Resulting in a Technical Specification Violation."
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Mr. S. J. Collins, NRC Regional Administrator, Region I Mr. G. K. Hunegs, NRC Senior Resident Inspector
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3/4 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/3012007 (6-2004)
, the NRC may sfor each block) not conduct or sponsor, and a person Is not required to respond to. the digits/characters frecblk)Information collection.
- 3. PAGE Nine Mile Point, Unit 1 05000220 1 OF 5 4.TITLE Fuel Moved with an Inoperable Source Range Monitor Due to Human Error Resulting in a Technical Specification Violation
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILMES INVOLVED IONA REFACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 04 14 2005 2005 -
002 -
00 06 13 2005
- 9. OPERATING MODE 11 THIS REPORT IS SUBMlTrED PURSUANTTO THE REQUIREMENTS OF 10CFR§: (Checkall that apply) o 20.2201(b) 0 20.2203(a)(3)(i) 0 50.73(a)(2)(i)(C) 0 50.73(a)(2)(vii)
N Q 20.2201(d) 0 20.2203(a)(3)(ii) 0 50.73(a)(2)(ii)(A) 0 50.73(a)(2)(viii)(A) o 20.2203(a)(1) 0 20.2203(a)(4) 0 50.73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B) 0_ 20.2203(a)(2)(i) 0 50.36(c)(1)(i)(A) 0 50.73(a)(2)(iii) 0 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 0
20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x) o 20.2203(a)(2)(iii) 0 50.36(c)(2) 0 50.73(a)(2)(v)(A) 0 73.71(a)(4) o0 20.2203(a)(2)(iv) 0 50.46(a)(3)(li) 0 50.73(a)(2)(v)(B) 0 73.71(a)(5) 000 0 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(C) 0 OTHER o 20.2203(a)(2)(vi) 0 50.73(a)(2)(i (B) 0 50.73(a)(2)(v)(D)
Specify In Abstract below or In NRC Forn 366A
- 12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (Include Area Code)
M. Steven Leonard, General Supervisor Licensing 315-349-4039
- 13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FAGTRRJR TO EPOCtXM FACTURER TO EPIX A
lG RI GE T Y TT
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR SUBMISSION O YES (if yes, complete 15. EXPECTED SUBMISSION DATE) 0 NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On April 14, 2005, at approximately 1654 hours0.0191 days <br />0.459 hours <br />0.00273 weeks <br />6.29347e-4 months <br />, with the reactor in the 'Refueling Condition" and spiral core reload in process, fuel moves were stopped when source range monitor (SRM) 12 failed to indicate any neutron counts when a twice burnt fuel bundle was placed adjacent to the SRM to achieve the required minimum count rate.
Technical Specification 3.5.3.b states, "During core alterations two SRMs shall be operable, one in and one adjacent to any core quadrant where fuel or control rods are being moved. Operable SRMs shall have a minimum of 3 counts per second except as specified in d and e below." Contrary to this, fuel was moved adjacent to an inoperable SRM (12).
The SRM failed to indicate any counts because the SRM instrumentation cabling was left disconnected following a maintenance activity earlier in the outage. The cause of this event involved human performance errors associated with failure to adhere to maintenance work instructions. Had the work instructions been implemented as written, the event would not have occurred.
NRC FORM 366(6.2004)
PRINTED ON RECYCLED PAPER NRC FORM 366 (6-2004)
PRINTED ON RECYCLED PAPER (if more space Is required, use additional copies of (If more spaceIsrequireduseadditionalcopiesofNRCFom,366A) (17)
II. Cause of Event (Continued)
Contributing causes included:
Inadequate pre-job briefs. The pre-job briefs were not thorough and their content was inadequate. Work packages were not present at the pre-job briefs and details about the entire work scope were not known. The maintenance crew and undervessel team did not conduct an integrated pre-job brief, even though the work procedures required an interface to occur.
Inadequate self checking. The undervessel coordinator did not use the STAR (Stop, Think, Act, and Review) human performance tool effectively while reviewing work documents and the maintenance crew did not display a questioning attitude when finding the nuclear instrumentation cables already disconnected.
Ill. Analysis of Event No other systems or components were inoperable at the start of the event that contributed to the severity of the event.
The condition of the inoperable SRM did not result in any required automatic plant response nor did it initiate any plant transient or directly impact the operability of any other equipment. All control rod drive mechanisms were installed in the reactor and all control rods were fully inserted prior to the event to maintain full shutdown margin.
Technical Specification 3.5.3, Extended Core and Control Rod Drive Maintenance, applies to core reactivity limitations during major core alterations. The objective is to assure that inadvertent criticality does not result when control rods are being removed from the core. Technical Specification 3.5.3.b requires two operable SRMs, one in and one adjacent to any core quadrant where fuel is being moved. Contrary to this, the SRM in the core quadrant into which fuel was moved was not operable due to cables being disconnected. The inoperable SRM was identified when the first fuel bundle was moved into the quadrant.
Because only a single fuel bundle was placed in the quadrant associated with the inoperable SRM, there was no chance of an inadvertent criticality since a single bundle cannot provide the required geometry and neutron source necessary to support criticality. This is based upon the fact that the core is designed to be subcritical with all bundles loaded and one control rod fully withdrawn. Unit 1 Technical Specification 3.5.3.e is designed to prevent an inadvertent criticality by allowing no more than two bundles to be placed in a quadrant during a spiral reload to verify SRM operability before proceeding with loading additional fuel.
The availability of systems or components that are needed to shutdown the reactor or maintain safe shutdown conditions, remove residual heat, control the release of radioactive material, or mitigate the consequences of an accident were not impacted during this event. Three of four SRMs were operable during this event. The SRMs are provided to monitor the core during periods of station shutdown and to guide the operator during refueling operations and station startup. Three operable SRMs ensures adequate coverage for all possible critical configurations produced by fuel loading or dispersed withdrawals of control rods during station startup. At the time of the event, all control rods were fully inserted. Because the probability of fuel damage was not increased during the event and the condition did not challenge the limiting transient/accident condition already analyzed for the cycle, the core damage risk was not increased.
Had the operators not recognized the inoperable condition of the SRM when the first bundle was placed next to SRM 12, per Technical Specification 3.5.3.e., the operators would have been required to verify SRM 12 operability when a second fuel bundle was placed next to SRM 12. Technical Specification 3.5.3.e. requires plant operators to obtain and maintain 3 cps on the SRM before more than two fuel bundles are moved into the quadrant. When the operators stopped fuel moves after the first bundle was moved next to SRM 12, they ensured Technical Specification 3.5.3.e. was not challenged. Therefore, there was no possibility of an inadvertent criticality resulting.
NRC FORM 360A (I-200)
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, fI (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
V. Additional Information
A. Failed Components:
There were no equipment or component failures associated with this event caused by degradation or piece-part failure. The inoperability of the SRM was caused by instrumentation cabling being left disconnected following maintenance work due to human error. The inoperable SRM did not result in the failure of other functions or components.
B. Previous Similar Events
During reactor startup from refueling outage '17 (April 2003), IRM 15 failed to respond to a neutron flux.,
Troubleshooting revealed the undervessel detector connector was disconnected. The cause of the event focused on failure to perform adequate post maintenance testing (PMT), Characterization (CHAR) testing, as originally scheduled. Review of the associated connector work performed by Constellation I&C revealed the IRM 15 undervessel Lemo connector was not fully seated. The work package was completed, however the CHAR test which had been scope-added into the refueling outage was deleted based on a false assumption that the IRM 15 connector was never disconnected, when in fact it was. There are some parallels with this event in that the IRM 15 undervessel connector was not fully seated and that assumptions were made about the PMT based on false information and it appears to be a lack of validation and verification of that information. This is similar to the SRM 12 and IRM 11 and 15 events in refueling outage 18 in that mis-communication and assumptions were made on who performed the reconnects and what work document completed the work.
C. Identification of systems and components referred to in this Licensee Event Report:
Components IEEE 805 System ID IEEE 803A Function Source Range Monitor (SRM)
IG RI Intermediate Range Monitor (IRM)
IG RI Reactor Protection System JC N/A Spent Fuel Pool (SFP)
DB N/A Vessel, Reactor AD RPV Control Rods AA 75 Nuclear Fuel AC N/A