05000368/LER-2015-001, Regarding Purge Radiation Monitor Discovered Inoperable During Fuel Movement
| ML15355A398 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 12/21/2015 |
| From: | Pyle S Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2CAN121503 LER 15-001-00 | |
| Download: ML15355A398 (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)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 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)(iii) 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)(vii), Common Cause Inoperability 10 CFR 50.73(b)(5) |
| 3682015001R00 - NRC Website | |
text
2CAN121503 10CFR 50.73 December 21, 2015 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
Subject:
Licensee Event Report 50-368/2015-001-00 Purge Radiation Monitor Discovered Inoperable During Fuel Movement Arkansas Nuclear One - Unit 2 Docket Numbers 50-368 Licensee Number NPF-6
Dear Sir or Madam:
Pursuant to the reporting requirements of 10 CFR 50.73, attached is the subject Licensee Event Report entitled, "Purge Radiation Monitor Discovered Inoperable During Fuel Movement."
There are no new commitments contained in this submittal.
Should you have any questions concerning this issue, please contact me.
Sincerely, ORIGINAL SIGNED BY DAVID B. BICE (ACTING REGULATORY ASSURANCE MANAGER) FOR STEPHENIE L. PYLE SLP/mkh Attachment: Licensee Event Report 50-368/2015-001-00 Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 Stephenie, L. Pyle Manager, Regulatory Assurance Arkansas Nuclear One
2CAN121503 Page 2 of 2 cc:
Mr. Marc L. Dapas Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 NRC Senior Resident Inspector Arkansas Nuclear One P.O. Box 310 London, AR 72847 Institute of Nuclear Power Operations 700 Galleria Parkway Atlanta, GA 30339-5957 LEREvents@inpo.org
NRC FORM 366 (11-2015)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the FOI, Privacy and Information Collections Branch (T-5 F53),
U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects.resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
LICENSEE EVENT REPORT (LER)
(See Page 2 for required number of digits/characters for each block)
- 1. FACILITY NAME Arkansas Nuclear One, Unit 2
- 2. DOCKET NUMBER 05000368
- 3. PAGE 1 OF 5
- 4. TITLE Purge Radiation Monitor Discovered Inoperable During Fuel Movement.
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.
MONTH DAY YEAR FACILITY NAME N/A DOCKET NUMBER 05000 10 26 2015 2015 -- 001 -- 00 12 21 2015 FACILITY NAME N/A DOCKET NUMBER 05000
- 9. OPERATING MODE 6
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 20.2201(b) 20.2201(d) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(2)(v) 20.2203(a)(2)(vi) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.36(c)(1)(i)(A) 50.36(c)(1)(ii)(A) 50.36(c)(2) 50.46(a)(3)(ii) 50.73(a)(2)(i)(A) 50.73(a)(2)(i)(B) 50.73(a)(2)(i)(C) 50.73(a)(2)(ii)(A) 50.73(a)(2)(ii)(B) 50.73(a)(2)(iii) 50.73(a)(2)(iv)(A) 50.73(a)(2)(v)(A) 50.73(a)(2)(v)(B) 50.73(a)(2)(v)(C) 50.73(a)(2)(v)(D) 50.73(a)(2)(vii)
OTHER Specify in Abstract below or in A.
Plant Status At the time this condition was discovered, Arkansas Nuclear One, Unit 2 (ANO-2) was operating in Mode 6 during scheduled refueling outage, 2R24, with fuel handling activities in progress in the Containment Building [NH].
B.
Event Description
ANO-2 Technical Specification (TS) 3.3.3.1 requires the Containment Purge and Exhaust Isolation Process Monitor to be operable in Modes 5 and 6. On October 25, 2015, ANO-2 was defueled when the power for the Containment Building Purge Radiation Monitor Sample Pump was transferred from the normal power supply to the alternate power supply during preparation for an electrical bus outage to clean and inspect the associated normal 480 VAC load center [ED]. The sample pump secured as designed during the momentary power loss while shifting power from the normal power supply to the alternate power supply, resulting in a loss of sample flow to the Containment Purge and Exhaust Isolation Process Monitor [IL].
On October 26, 2015, at 1803 CDT, ANO-2 entered Mode 6 and commenced refueling operations. On October 26, 2015, at 2300 CDT, the Containment Purge and Exhaust Isolation Process Monitor was identified as inoperable due to not having its required sample pump in operation. ANO-2 entered TS 3.3.3.1, Action B, suspended fuel movement, verified a purge was not in progress, and verified the applicable Super Particulate Iodine and Noble Gas (SPING) monitor was functional and in operation. On October 26, 2015, at 2307 CDT, the Containment Building Purge Radiation Monitor Sample Pump was restarted and at 2308 CDT, ANO-2 exited TS 3.3.3.1, Action B. For approximately 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> ANO-2 was in Mode 6 with refueling operations in progress while the Containment Purge and Exhaust Isolation Process Monitor was inoperable.
C.
Apparent Causes A human performance error resulted in this condition due to using the wrong sample flow indication to verify flow to the Containment Purge and Exhaust Isolation Process Monitor.
D.
Corrective Actions
Corrective actions completed:
Performed a human performance error review for this event.
Corrective actions planned include:
Revising procedure OP-2107.007, Engineered Safety Features Electrical Bus Outage, Attachment W, to add clarification of starting the Containment Building Purge Radiation Monitor Sample Pump and to clarify the location of its flow indication.
Revising procedure OP-2104.033, Containment Atmosphere Control, to add a step to verify the Containment Building Purge Radiation Monitor Sample Pump is operating when restarting the Containment Purge Exhaust Fan for continuous ventilation.
Revising checklist OPS-B36, Core Alterations Checklist, to require verification that the Containment Building Radiation Monitor Sample Pump is in operation prior to Core Alterations.
E.
Safety Significance
Failure of two entire fuel assemblies is the bounding fuel handing accident for ANO-2. The offsite dose consequences from gases released during a fuel handling accident directly to the atmosphere with no filtration, assuming the reactor has been shut down for 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> (TS prohibits fuel handling operations prior to this time), will not exceed the acceptable limits of 10 CFR 50.67. The stated condition in this report affected the monitoring and automatic isolation of the Containment Purge exhaust pathway. The condition would not have prohibited the pathway from being manually secured from the Control Room. The SPING continued to monitor the release pathway and would have provided Control Room alarm upon high radiation signal.
Fuel handling is continuously attended and a fuel handling accident would be required to release the radiation from the fuel assembly. ANO-2 has a specific procedure for a Fuel Handling Accident which utilizes multiple diverse indications to identify fuel damage. The procedure directs that Containment Purge be secured. Based on the alternate indications available to identify a fuel handling accident, the procedural guidance to secure Containment Purge if a fuel handling accident occurs, and the bounding accident requiring two entire assemblies to be damaged and the gases exhausted through an unfiltered exhaust path, this condition had minimal safety significance.
F.
Basis For Reportability TS 3.3.3.1 requires that the radiation monitoring instrumentation channels shown in Table 3.3-6 shall be operable with the alarm/trip setpoints within the specified limits.
Table 3.3-6 requires the Containment Purge and Exhaust Isolation Process Monitor to be operable in Modes 5 and 6 or to take action in accordance with Action 16.
Action 16 - With the number of operable channels one less than the minimum channels operable requirement, complete the following:
a.
If performing core alterations or moving irradiated fuel within the reactor building, secure the containment purge system or suspend core alterations and movement of irradiated fuel within the reactor building.
b.
If a containment purge is in progress, secure the containment purge system.
c.
If continuously ventilating, verify the SPING monitor operable or perform the actions of the Offsite Dose Calculation Manual, Appendix 2, Table 2.2-1, or secure the containment purge system.
The operability of the radiation monitoring channel ensures that the radiation levels are continually measured in the areas served by the individual channel and the alarm or automatic action is initiated when the radiation level setpoint is exceeded.
Movement of irradiated fuel assemblies on October 26, 2015, with the Containment Purge and Exhaust Isolation Process Monitor inoperable, resulted in operation prohibited by TS.
This report is submitted in accordance with 10 CFR 50.73(a)(2)(i)(B).
G.
Additional Information
10 CFR 50.73(b)(5) states that this report shall contain reference to any previous similar events at the same plant that are known to the licensee. NUREG-1022, Revision 3, reporting guidance states that the phrase previous occurrences should include previous events or conditions that involved the same underlying concern or reason as this event, such as the same root cause, failure, or sequence of events.
A review of the ANO corrective action program and Licensee Event Reports for the previous three years was performed. The following ANO events were related to conditions prohibited by technical specifications.
October 24, 2014 (2CAN101402), Technical Specification 3.0.4 Violation due to a Mode Change with an Inoperable Emergency Feedwater Pump May 15, 2014 (2CAN051405), Operation of Switchgear Rooms Ventilation Prohibited by Technical Specifications October 21, 2013 (2CAN101303), An Inoperable Offsite Power Supply Transformer due to an Inadequate Design Configuration Results in a Condition Prohibited by Technical Specifications April 04, 2013 (0CAN041302), An Inoperable Emergency Control Room Chiller due to Maintenance Error Results in a Prevented Safety Function Entergy Industry Identification System (EIIS) codes are identified in the text as [XX].
A.
Plant Status At the time this condition was discovered, Arkansas Nuclear One, Unit 2 (ANO-2) was operating in Mode 6 during scheduled refueling outage, 2R24, with fuel handling activities in progress in the Containment Building [NH].
B.
Event Description
ANO-2 Technical Specification (TS) 3.3.3.1 requires the Containment Purge and Exhaust Isolation Process Monitor to be operable in Modes 5 and 6. On October 25, 2015, ANO-2 was defueled when the power for the Containment Building Purge Radiation Monitor Sample Pump was transferred from the normal power supply to the alternate power supply during preparation for an electrical bus outage to clean and inspect the associated normal 480 VAC load center [ED]. The sample pump secured as designed during the momentary power loss while shifting power from the normal power supply to the alternate power supply, resulting in a loss of sample flow to the Containment Purge and Exhaust Isolation Process Monitor [IL].
On October 26, 2015, at 1803 CDT, ANO-2 entered Mode 6 and commenced refueling operations. On October 26, 2015, at 2300 CDT, the Containment Purge and Exhaust Isolation Process Monitor was identified as inoperable due to not having its required sample pump in operation. ANO-2 entered TS 3.3.3.1, Action B, suspended fuel movement, verified a purge was not in progress, and verified the applicable Super Particulate Iodine and Noble Gas (SPING) monitor was functional and in operation. On October 26, 2015, at 2307 CDT, the Containment Building Purge Radiation Monitor Sample Pump was restarted and at 2308 CDT, ANO-2 exited TS 3.3.3.1, Action B. For approximately 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> ANO-2 was in Mode 6 with refueling operations in progress while the Containment Purge and Exhaust Isolation Process Monitor was inoperable.
C.
Apparent Causes A human performance error resulted in this condition due to using the wrong sample flow indication to verify flow to the Containment Purge and Exhaust Isolation Process Monitor.
D.
Corrective Actions
Corrective actions completed:
Performed a human performance error review for this event.
Corrective actions planned include:
Revising procedure OP-2107.007, Engineered Safety Features Electrical Bus Outage, Attachment W, to add clarification of starting the Containment Building Purge Radiation Monitor Sample Pump and to clarify the location of its flow indication.
Revising procedure OP-2104.033, Containment Atmosphere Control, to add a step to verify the Containment Building Purge Radiation Monitor Sample Pump is operating when restarting the Containment Purge Exhaust Fan for continuous ventilation.
Revising checklist OPS-B36, Core Alterations Checklist, to require verification that the Containment Building Radiation Monitor Sample Pump is in operation prior to Core Alterations.
E.
Safety Significance
Failure of two entire fuel assemblies is the bounding fuel handing accident for ANO-2. The offsite dose consequences from gases released during a fuel handling accident directly to the atmosphere with no filtration, assuming the reactor has been shut down for 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> (TS prohibits fuel handling operations prior to this time), will not exceed the acceptable limits of 10 CFR 50.67. The stated condition in this report affected the monitoring and automatic isolation of the Containment Purge exhaust pathway. The condition would not have prohibited the pathway from being manually secured from the Control Room. The SPING continued to monitor the release pathway and would have provided Control Room alarm upon high radiation signal.
Fuel handling is continuously attended and a fuel handling accident would be required to release the radiation from the fuel assembly. ANO-2 has a specific procedure for a Fuel Handling Accident which utilizes multiple diverse indications to identify fuel damage. The procedure directs that Containment Purge be secured. Based on the alternate indications available to identify a fuel handling accident, the procedural guidance to secure Containment Purge if a fuel handling accident occurs, and the bounding accident requiring two entire assemblies to be damaged and the gases exhausted through an unfiltered exhaust path, this condition had minimal safety significance.
F.
Basis For Reportability TS 3.3.3.1 requires that the radiation monitoring instrumentation channels shown in Table 3.3-6 shall be operable with the alarm/trip setpoints within the specified limits.
Table 3.3-6 requires the Containment Purge and Exhaust Isolation Process Monitor to be operable in Modes 5 and 6 or to take action in accordance with Action 16.
Action 16 - With the number of operable channels one less than the minimum channels operable requirement, complete the following:
a.
If performing core alterations or moving irradiated fuel within the reactor building, secure the containment purge system or suspend core alterations and movement of irradiated fuel within the reactor building.
b.
If a containment purge is in progress, secure the containment purge system.
c.
If continuously ventilating, verify the SPING monitor operable or perform the actions of the Offsite Dose Calculation Manual, Appendix 2, Table 2.2-1, or secure the containment purge system.
The operability of the radiation monitoring channel ensures that the radiation levels are continually measured in the areas served by the individual channel and the alarm or automatic action is initiated when the radiation level setpoint is exceeded.
Movement of irradiated fuel assemblies on October 26, 2015, with the Containment Purge and Exhaust Isolation Process Monitor inoperable, resulted in operation prohibited by TS.
This report is submitted in accordance with 10 CFR 50.73(a)(2)(i)(B).
G.
Additional Information
10 CFR 50.73(b)(5) states that this report shall contain reference to any previous similar events at the same plant that are known to the licensee. NUREG-1022, Revision 3, reporting guidance states that the phrase previous occurrences should include previous events or conditions that involved the same underlying concern or reason as this event, such as the same root cause, failure, or sequence of events.
A review of the ANO corrective action program and Licensee Event Reports for the previous three years was performed. The following ANO events were related to conditions prohibited by technical specifications.
October 24, 2014 (2CAN101402), Technical Specification 3.0.4 Violation due to a Mode Change with an Inoperable Emergency Feedwater Pump May 15, 2014 (2CAN051405), Operation of Switchgear Rooms Ventilation Prohibited by Technical Specifications October 21, 2013 (2CAN101303), An Inoperable Offsite Power Supply Transformer due to an Inadequate Design Configuration Results in a Condition Prohibited by Technical Specifications April 04, 2013 (0CAN041302), An Inoperable Emergency Control Room Chiller due to Maintenance Error Results in a Prevented Safety Function Entergy Industry Identification System (EIIS) codes are identified in the text as [XX].