05000298/LER-2016-003, Scaffold Construction Places Plant in a Condition Prohibited by Technical Specifications
| ML16326A261 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 11/09/2016 |
| From: | Limpias O Nebraska Public Power District (NPPD) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 16-003-00 | |
| Download: ML16326A261 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(ii) 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)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2982016003R00 - NRC Website | |
text
Nebraska Public Power District Always there when you need us NLS2016065 November 9, 2016 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, b.C. 20555-0001
Subject:
Licensee Event Report No. 2016-003-00 Cooper Nuclear Station, Docket No. 50-298, DPR-46
Dear Sir or Madam:
The purpose of this correspondence is to forward Licensee Event Report 2016-003-00.
- There are no new commitments contained in this letter.
Sincerely,
~LA.Li~.,
Vice Presi ent Nuclear-
. Chief Nuclear Officer
/jo Attachment: Licensee Event Report 2016-003-00 cc:
Regional Administrator w/attachment USNRC - Region IV NPG Distribution w/attachment Cooper Project Manager w/attachment INPO Records Center w/attachment USNRC - NRR Plant Licensing Branch IV-2 via ICES entry Senior Resident Inspeetor w/attachment USNRC-CNS SRAB Administrator w/attachment SORC Chairman w/attachment
- CNS Records w/attachment COOPER NUCLEAR STATION P.O. Box 98 /Brownville, NE 68321-0098 Telephone: (402) 825-3811 /Fax: (402) 825-5211 www.nppd.com
- NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BYOMB: NO. 3150-0104 EXPIRES: 10/31/2018 (11-2015)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Cooper Nuclear Station 05000298 1of4
- 4. TITLE Scaffold Construction Places Plant in a Condition Prohibited by Technical Specifications
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED YEAR I SEQUENTIAL I REV FACILITY NAME DOCKET MONTH DAY YEAR NUMBER NO.
MONTH DAY YEAR 05000 FACILITY NAME DOCKET 09 14 2016 2016 003 -
00 11 09 2016 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
D 20.2201(b)
D 20.2203(a)(3)(i) 0 50.73(a)(2)(ii)(A) 0 50. i3(a)(2)(viii)(A) 1 D 20.2201(d)
D 20.2203(a)(3)(ii) 0 50.73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B)
D 20.2203(a)(1)
D 20.2203(a)(4)
D 50.73(a)(2)(ii) 0 50. 73(a)(2)(ix)(A)
D 20.2203(a)(2)(i) 0 50.36(c)(1)(i)(A)
D 50. 73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
D 20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(v)(A)
D 73.71(a)(4)
- 10. POWER LEVEL D 20.2203(a)(2)(iii)
D 50.36(c)(2)
D 50.73(a)(2)(v)(B)
D 73.71(a)(5) 0 20.2203(a)(2)(iv)
D 50.46(a)(3)(ii)
D 50.73(a)(2)(v)(C)
D 73.77(a)(1) 089 D 20.2203(a)(2)(v) 0 50. 73(a)(2)(i)(A)
D 50. 73(a)(2)(v)(D)
D 73.77(a)(2)(i)
D 20.2203(a)(2)(vi)
~ 50. 73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 73.77(a)(2)(ii) t*
0 50. 73(a)(2)(i)(C) 0 OTHER Specify in Abstract below or in =
PLANT STATUS REV NO.
- - 00 Cooper Nuclear Station was in Mode 1, Power Operation, at 89 percent power, approaching the end of Cycle 29 in two-loop operation, at the time the condition was identified.
BACKGROUND The safety objective of the Secondary Containment system [EllS:NG] in conjunction with othei::
engineering safeguards and nuclear safety systems is to limit the release to the environs of radipactive material so that off-site doses from a postulated design basis accident will be below the values.'..
permitted.
The reactor building isolation and control system serves to trip the reactor building [EllS:NG] supply and exhaust fans [EllS:FAN], isolate the normal ventilation system and provide the starting signals for the Standby Gas Treatment (SGT) [EllS:BH] system in the event of a postulated Loss of Coolant Accident inside the drywall [EllS:NG] or the postulated fuel handling accident in the reactor building.
Two normally open dampers [EllS:DMP], in series, are provided both in the supply path and two exhaust paths for the reactor building and the two supply and exhaust paths for Reactor Recirculation Motor Generator (RRMG) set ventilation. Each set of dampers consists of one air actuated damper, supplied by instrument air backed up by an accumulator [EllS:ACC] with an assured one-hour supply capacity, and a motor operated damper. These dampers ensure redundant, diverse isolation capability for the reactor building in the event of a release of radioactive material to the reactor building. These dampers close automatically on a Group 6 (Secondary Containment Isolation) isolation signal.
HV-AOV-265 is the RRMG Ventilation Supply Outboard Isolation Valve for RRMG 1 B. This air operated valve (AOV) is normally open during plant operation. In addition to driving the actuator shaft, the air actuator cylinder physically rotates when the valve is opened or closed. This results in a large actuator movement path that includes the actuator shaft, cylinder, valve disc arm, and the airlines that connect to the cylinder.
EVENT DESCRIPTION
On September 14, 2016, during testing of the Reactor Recirculation Motor Generator Ventilation Air Operated Isolation Valves, the control switch for HV-AOV-265 was taken to close for valve stroke timing.
The valve failed to close. HV-AOV-265 was declared inoperable and Technical Specification (TS)
Limiting Condition for Operation (LCO) 3.6.4.2, Condition A, Required Action A.1, "Isolate the affected penetration flow path by use of at least one closed and de-activated valve within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />," was entered.
In addition, Operations commenced preparations for transitioning the plant to single loop operation, including reducing power to approximately 50 percent to support removing the associated RRMG set from service.
Operations attempted to close HV-AOV-265 while an Engineer was stationed locally to observe the valve's operation. The Engineer identified that during the attempt to close the valve, the air supply line became pinched between the moving cylinder of the valve actuator and a scaffold that had been erected on June 29, 2016, to support work on a different valve.
NRG FORM 366 (06-2016)
Page 3 of4 NRC FORM 366 (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BYOMB: NO. 3150-0104 EXPIRES: 10/31/2018 LICENSEE EVENT REPORT (LER)
(See Page 2 for required number of digits/characters for each block}
, the NRG may not conduct or sponsor, and a http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)
person is not required to respond to, the information collection.
- 3. LER NUMBER Cooper Nuclear Station 05000-298 NARRATIVE YEAR 2016 SEQUENTIAL NUMBER
- - 003 REV NO.
- - 00 As such, air was restricted from exhausting from the air cylinder, pneumatically locking the piston and preventing the valve from closing. Further investigation revealed that the airline had been crimped and required replacement.
After modifying the scaffold to remove the interference with the operation of the valve, the airline for HV-A0-265 was replaced and the valve stroke testing was re-performed satisfactorily. HV-A0-265 was declared operable and TS LCO 3.6.4.2 was exited. Upon exiting the LCO, activities to prepare for transition to single loop operation were terminated.
BASIS FOR REPORT This condition is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by TS because the scaffolding, installed in June 2016, was in a position to block the movement of the valve since that time.
SAFETY SIGNIFICANCE
The safety significance of this event is low. Secondary Containment AOV, HV-A0-265, could not be fully closed; however, the redundant motor operated valve in the RRMG B ventilation inlet flow path( HV-M0-264, provided the required safety function for Secondary Containment isolation. This event didmot cause an impact to the safety of the general public, nuclear safety, industrial safety, or radiological safety.
CAUSE
The root cause of the event was determined to be that the personnel involved in the planning, construction, and inspection of the scaffold built for HV-MOV-264 were not aware of the external movement path of HV-AOV-265 actuator.
CORRECTIVE ACTIONS
Revise Maintenance Procedure 7.0.7, "Scaffolding Construction and Control," to include specific guidance for the planning, building and inspection of scaffolds in the vicinity of the AOVs listed below:
PC-A0-236AV HV-A0-267AV HV-A0-257AV HV-A0-263AV HV-A0-265AV Installed signs in the areas near the AOVs listed below to warn personnel of the external movement of these AOVs:
HV-A0-257AV HV-A0-265AV HV-AO-FCV1045A PC-A0-234AV NRC FORM 366 (06-2016)
HV-A0-259AV HV-A0-267 AV HV-AO-FCV10458 PC-A0-236AV HV-A0-261AV HV-A0-269AV HV-AO-FCV1046 HV-A0-263AV HV-A0-271 AV HV-AO-FCV1047
NRC FORM 366 (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
(See Page 2 for required number of digits/characters for each block)
Page 4 of 4 APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018
, the NRG may not conduct or sponsor, and a http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)
person is not required to respond to, the information collection.
- 3. LER NUMBER Cooper Nuclear Station 05000-298 NARRATIVE PREVIOUS EVENTS YEAR 2016 SEQUENTIAL NUMBER
- - 003 REV NO.
- - 00 There have been no events reported in the last three years related to scaffold construction impacting the ability of components to perform their safety function.
NRC FORM 366 (06-2016)