05000282/LER-2015-005, Regarding Possible Misapplication of C18.1, Engineered Safeguards Equipment Support Systems
| ML15313A480 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  (DPR-042) |
| Issue date: | 11/09/2015 |
| From: | Davison K Northern States Power Co, Xcel Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-PI-15-096 LER 15-005-00 | |
| Download: ML15313A480 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) |
| 2822015005R00 - NRC Website | |
text
(l Xcel Energy@
NOV 0 9 2015 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Unit 1 Docket: 50-282 Renewed License No. DPR-42 L-PI-15-096 10 CFR 50.73 LER 50-282-2015-005-00, Possible Misapplication of C 18.1, Engineered Safeguards Equipment Support Systems Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), encloses Licensee Event Report (LER) 50-282/2015-005-00, Possible Misapplication of C18.1, Engineered Safeguards Equipment Support Systems.
Summary of Commitments This letter contains no new commitments and no changes to existing commitments.
- ??"',j)t!w~
Kevin Davison Site Vice President, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota Enclosure cc:
Administrator, Region Ill, USNRC Project Manager, Prairie Island Nuclear Generating Plant (PINGP), USNRC Resident Inspector, PINGP, USNRC Department of Commerce, State of Minnesota 1717 Wakonade Drive East
- Welch, Minnesota 55089-9642 Telephone: 651.388.1121
ENCLOSURE LICENSEE EVENT REPORT 50-282/2015-005-00 4 Pages Follow
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 (01-2014)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 6. LER NUMBER
- 3. PAGE YEAR I SEQUENTIAL I REV 2 OF 4 NUMBER NO 2015 005 00 On September 11, 2015, it was identified that 122 Control Room Chiller was removed from service and control valve CV-31837 (121/122 Control Room Chiller Outlet) and CV-31838 (121/122 Control Room Chiller Inlet) were closed. This separated the A and B trains of Safeguards Chilled Water. The 122 Control Room Chilled Water Pump had been stopped and the controlling breaker BKR 122G-12 had been opened. At this point there was no Train B Safeguards Chilled Water. This isolated Train B Safeguards Chilled Water and rendered Bus 16 Unit Cooler non-functional, which will result in unacceptable temperatures in the associated bus room during a postulated High Energy Line Break (HELB).
Bus 16 would not have performed its safety function and was inoperable for greater then the time allowed by Tech Spec. During the last three (3) years this occurred on five (5) separate occasions when 122 Control Room Chiller was isolated. Bus 16 was inoperable for approximately 52 days 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />.
Technical Specification (Tech Spec) 3.8.9 for Distribution Systems-Operating was not entered and the required actions were not taken to restore to an operable status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or to enter MODE 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and MODE 5 in 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
This is a reportable event under 10 CFR 50.73(a)(2)(i)(b), Operation or Condition Prohibited by Tech Spec.
Extent of Condition was performed on Bus 15 in response to Bus 16 inoperability. When 121 Control Room Chiller was removed from service, this isolated Train A Safeguards Chilled Water and rendered Bus 15 Unit Cooler non-functional. Once the unit cooler was non-functional Bus 15 was inoperable.
This occurred on two (2) separate occasions when 121 Control Room Chiller was isolated. Bus 15 was inoperable for approximately 21 days 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />.
A review of the Operations Tech Spec Logs indicated that at no time were both Buses 15 and 16 out-of-service at the same time, therefore there was no loss of safety function.
EVENT ANALYSIS
The Safeguards Chilled Water System circulates chilled water to provide ambient air cooling to essential areas. These areas include the control room; safeguards switchgear (Unit 1 4160 VAG (4kV) and 480 VAG bus) rooms; the residual heat removal (RHR) pump pits; the relay room, including 1 EllS System Code-EA 2 EllS System Code-Bl
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 1/31/2017
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 6. LER NUMBER
- 3. PAGE YEAR I SEQUENTIAL I REV 2 OF 4 NUMBER NO 2015 005 00 On September 11, 2015, it was identified that 122 Control Room Chiller was removed from service and control valve CV-31837 (121/122 Control Room Chiller Outlet) and CV-31838 (121/122 Control Room Chiller Inlet) were closed. This separated the A and B trains of Safeguards Chilled Water. The 122 Control Room Chilled Water Pump had been stopped and the controlling breaker BKR 122G-12 had been opened. At this point there was no Train B Safeguards Chilled Water. This isolated Train B Safeguards Chilled Water and rendered Bus 16 Unit Cooler non-functional, which will result in unacceptable temperatures in the associated bus room during a postulated High Energy Line Break (HELB).
Bus 16 would not have performed its safety function and was inoperable for greater then the time allowed by Tech Spec. During the last three (3) years this occurred on five (5) separate occasions when 122 Control Room Chiller was isolated. Bus 16 was inoperable for approximately 52 days 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />.
Technical Specification (Tech Spec) 3.8.9 for Distribution Systems-Operating was not entered and the required actions were not taken to restore to an operable status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or to enter MODE 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and MODE 5 in 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
This is a reportable event under 10 CFR 50.73(a)(2)(i)(b), Operation or Condition Prohibited by Tech Spec.
Extent of Condition was performed on Bus 15 in response to Bus 16 inoperability. When 121 Control Room Chiller was removed from service, this isolated Train A Safeguards Chilled Water and rendered Bus 15 Unit Cooler non-functional. Once the unit cooler was non-functional Bus 15 was inoperable.
This occurred on two (2) separate occasions when 121 Control Room Chiller was isolated. Bus 15 was inoperable for approximately 21 days 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />.
A review of the Operations Tech Spec Logs indicated that at no time were both Buses 15 and 16 out-of-service at the same time, therefore there was no loss of safety function.
EVENT ANALYSIS
The Safeguards Chilled Water System circulates chilled water to provide ambient air cooling to essential areas. These areas include the control room; safeguards switchgear (Unit 1 4160 VAG (4kV) and 480 VAG bus) rooms; the residual heat removal (RHR) pump pits; the relay room, including 1 EllS System Code-EA 2 EllS System Code-Bl (01-204)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET APPROVED BY OMB: NO. 3150-0104 EXPIRES: 1/31/2017
, the NRC may not conduct or sponsor, and a person Is not required to respond to, the information collection.
- 1.
FACILITY NAME I---...;,;2*.;,0.;;.0C;;.;,K,;;;;E-.T ---+-----,..:.:6*c...:::L:C::ER::'N"::U::':M=-:BE~R"---T--:-::::-:-I YEAR I SEQUENTIAL I REV
- 3. PAGE Prairie Island Nuclear Generating Plant Unit 1 05000 - 282 NUMBER NO 3 OF 4 2015 005 00 the old P-250 computer room; and the event monitoring (EM) equipment room. The system functions during both normal plant operations and during accident conditions. Function of the system is to remove heat generated by safety related equipment an accident condition. The system provides sufficient ventilation and cooling to maintain equipment operability. It does this by controlling temperatures within design ratings of the installed safety related systems. The system performs a safeguard function in that it cools critical equipment.
If one loop of the Safeguards Chilled Water system is assumed to be disabled (single active failure) in an accident scenario with safety injection signal, the other loop is available. In the affected loop, several rooms would suffer a loss of, or degraded, cooling.
Cooling would be lost to one Unit 1 4kV bus room. Ambient temperatures would be unacceptable for continued operation of the load sequencer in that bus. However, the load sequencer may have completed its function prior to the room temperature exceeding acceptable levels. In any case the other bus would still be available. The loss of Safeguards Chilled Water to the Bus Room Unit Cooler will result in unacceptable temperatures in the associated bus room during a postulated High Energy Line Break (HELB).
SAFETY SIGNIFICANCE
There are no Industrial, Environmental or Radiological consequences from this event. The potential nuclear consequence is that when Bus 16 is declared inoperable, there is a potential for a loss of one train (B) safeguards loads to Unit 1 ensuring the core is cooled in an accident condition. Tech Spec 3.8.9 for Distribution Systems-Operating was not entered and the required actions were not taken to restore to available and operable status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or to enter MODE 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and MODE 5 in 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
The actual regulatory consequence is that this event is reportable to the NRC under 10 CFR 50. 73(a)(2)(i)(B)
Operation or Condition Prohibited by Technical Specifications.
There were no radiological, environmental, or industrial impacts associated with this event, and PINGP did not adversely affect the health and safety of the public.
CAUSE
The apparent cause is that the procedure review process was not followed correctly to ensure that C18.1, Engineered Safeguards Equipment Support Systems was accurate and useable. (01-204)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1.
FACILITY NAME
- 2. DOCKET Prairie Island Nuclear Generating Plant Unit 1 05000-282
CORRECTIVE ACTION
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 1/31/2017
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 6. LER NUMBER
- 3. PAGE YEAR I SEQUENTIAL I REV NUMBER NO 4 OF 4 2015 005 00 Procedure change requests have been initiated to address the procedure deficiencies identified in C18.1, Engineered Safeguards Equipment Support Systems.
Revise JFG-FL-LDP-PH1-005G, Job Familiarization Guide-Use of Xcel Procedures and Practices Governing Plant Procedures with details to ensure that Validation Review responsibilities are covered during the appropriate discussions, using FP-G-DOC-04 as your guide.
PREVIOUS SIMILAR EVENTS
None.