05000282/LER-2015-006, Regarding Quarterly Containment Spray Pump Surveillance Test Method
| ML15278A519 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 10/05/2015 |
| From: | Davison K Northern States Power Co, Xcel Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-PI-15-089 LER 15-006-00 | |
| Download: ML15278A519 (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)(v), Loss of Safety Function |
| 2822015006R00 - NRC Website | |
text
Xcel Energy..
October 5, 2015 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Unit 1 and 2 Dockets: 50-282 and 50-306 Renewed License Nos. DPR-42 and DPR-60 L-PI-15-089 10 CFR 50.73 LER 50-282/2015-006-00, Quarterly Containment Spray Pump Surveillance Test Methodology Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), encloses Licensee Event Report (LER) 50-282/2015-006-00, Quarterly Containment Spray Pump Surveillance Test Methodology.
Summary of Commitments This letter contains no new commitments and no changes to existing commitments.
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 50-282/2015-006-00 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 006 00 On August 4, 2015, a question concerning the quarterly Containment Sprai (CS) pump surveillance, procedures (SP) 1090 A[B] and 2090 A[B] was submitted into the corrective action program. Steps within the SPs were to use a vent2 or drain valve to drain the Containment Spray header before and after the SPs were conducted. This created an open flow path from the Containment into the Containment Spray rooms in the Auxiliary Building. The purpose of the draining activity was to check for leakage past the manual isolation valve on the Containment Spray Pump discharge header that is closed while the pump is running in recirculation mode during the test. In order to satisfy Tech Spec 3.6.3 (Containment Isolation Valves) required action A.1, a dedicated Operator in continuous communication with the control room was stationed in the Containment Spray pump room to close the vent/drain valve if a need for Containment Isolation were to occur.
The Containment procedure, 1 [2]C19.1 contains a limitation (4.8) which states "Administrative controls placed on any vent or drain valve within the credited containment isolation boundary SHALL include actions to CLOSE the valve and restore the CAP rapidly when a need for containment isolation is indicated. This action restores the double barrier seal." This led to the implication that Tech Spec 3.6.3 Note 1 could be applied to the draining activity.
Having the vent/drain valve opened to drain the CS header is not allowed by Tech Spec 3.6.3 A.1, in MODEs 1-4. The Containment pressure boundary function was adversely affected by opening the vent/drain valve, and the Containment vessel was inoperable as long as the vent or drain valve was open. This is reportable under 10 CFR 50.73(a)(2)(i)(B), operations or condition prohibited by Tech Spec.
During the conversion to lmprovedTech Spec (ITS) (circa 2002) the change management did not recognize that the addition of Tech Spec 3.6.3 Note 1 would disallow the previously accepted practice of opening Containment Isolation penetration vent and drain valves under administrative control.
The opening of the vent and drain valves created a flow path from the Containment into the CS pump room in the Auxiliary Building. This condition could have prevented fulfillment of a safety function that is needed to control the release of radioactive material. This event has occurred on both Unit 1 and Unit 2 within 3 years of the date of discovery, but not at the time of discovery so that an ENS notification is not required and an LER is required, reportable under 10 CFR 50.73(a)(2)(v)(C).
The apparent cause evaluation included an Extent of Condition. Results were that no other similar issues that involved manipulation of Containment Penetration valves was identified.
1 EllS System Code-BE 2 IEEE Component Code - VTV (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
EVENT ANALYSIS
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 3 OF 4 NUMBER NO 2015 006 00 The Primary Containment System consists of a steel structure and its associated engineered safety features systems. The Primary Containment System is a low leakage steel shell. The system, including all its penetrations, is designed to confine the radioactive materials that could be released by accidental loss of integrity of the Reactor Coolant System pressure boundary. Systems directly associated with the Primary Containment System include the Safety Injection, Containment Vessel Internal Spray, Containment Vessel Air Handling and Containment Isolation systems.
When the Containment Spray System is configured to drain the header, a 3/8-inch opening in the containment pressure boundary exists. The leakage from the Containment into the Auxiliary Building that would occur from an opening of this size during an accident would exceed the maximum allowable leakage rate of 0.15 percent by weight per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at the calculation peak containment internal pressure related to the design basis accident.
SAFETY SIGNIFICANCE
The potential Nuclear/Radiological consequence is that an opening in the Containment Barrier existed which could have exposed the Auxiliary Building to Containment environmental conditions.
During the performances of these SPs there was no adverse plant condition that could have released the Containment environment into the Auxiliary Building. 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. Administrative controls were in place, a dedicated Operator was in continuous communication with the control room was stationed in the Containment Spray pump room to close the vent/drain valve if a need for Containment Isolation were to occur.
CAUSE
The apparent cause is that the License Amendment implementation in 2002 for integrating Technical Specifications into Improved Technical Specifications did not identify when and how Tech Spec LCO 3.6.3 ACTIONS modifying note 1 applied to draining of the containment spray header from the Aux Building.
CORRECTIVE ACTION
Immediate Actions: The following SPs have been revised to remove steps for draining the CS header.
SP 1090A rev 25, 11 Containment Spray Pump Quarterly Test, Complete 09/08/2015 SP 1090B rev 24, 12 Containment Spray Pump Quarterly Test, Complete 08/14/2015 SP 2090A rev 21, 21 Containment Spray Pump Quarterly Test, Complete 09/08/2015 (01-204)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMS: NO. 3150-0104 EXPIRES: 1/31/2017 LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1.
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- 3. PAGE Prairie Island Nuclear Generating Plant Unit 1 05000 - 282 YEAR I SEQUENTIAL I REV NUMBER NO 4 OF 4 2015 006 00
Corrective Actions
Revise Containment Operating procedures (1C19.1 I 2C19.1) to:
1.) Clearly describe when and how to apply LCO 3.6.3 ACTIONS note 1, 2.) Ensure proper terminology using "dedicated" operator throughout procedure, 3.) Ensure administrative controls include the 60 second requirement to establish containment isolation, 4.) Remove limitation 4.5 and replace with direction that LCO condition entry is required prior to application of LCO 3.6.3 note 1, 5.) Remove limitation 4.8 and replace with direction that LCO 3.6.3 note 1 does not apply if opening vent or drain valves.
Revise TS 3.6.3 Basis to clearly describe when and how to apply LCO 3.6.3 ACTIONS note 1.
Conduct a training needs assessment for licensed operators to consider training for:
o The proper application of LCO 3.6.3 ACTIONS note 1 specifically:
Cannot apply it to opening vent and drain valves (flowpath valves only)
Must enter the applicable LCO condition first (cannot use it if not in an LCO condition)
Should not be used if the flowpath is not re-established by the activity (i.e.
upstream valve/boundary is being maintained closed) o Update IL T materials to enhance the discussion of how to apply TS notes (in general) using LCO 3.6.3 note 1 as the prime example.
PREVIOUS SIMILAR EVENTS
A LER historical search was conducted. No similar LER events at PINGP with the same apparent cause were identified in the last three years.