05000263/LER-2015-003, Regarding Use of the Reactor Water Cleanup System to Lower Level Without Declaring an Operation with a Potential to Drain the Reactor Vessel (OPDRV) with Secondary Containment Inoperable
| ML15194A408 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 07/13/2015 |
| From: | Gardner P Northern States Power Co, Xcel Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L -MT-15-054 LER 15-003-00 | |
| Download: ML15194A408 (5) | |
| 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 |
| LER closed by | |
| IR 05000263/2016004 (13 February 2017) | |
| 2632015003R00 - NRC Website | |
text
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July 13, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket 50-263 Renewed Facility Operating License No. DPR-22 Monticello Nuclear Generating Plant 2807 W County Road 75 Monticello, MN 55362 L -MT 054 10 CFR 50.73 LER 2015-003-00 "Use of the Reactor Water Cleanup System to Lower Level without Declaring an Operation with a Potential to Drain the Reactor Vessel (OPDRV) with Secondary Containment Inoperable" Enclosed is the Monticello Nuclear Generating Plant (MNGP) Licensee Event Report (LER) 2015-003-00 concerning use of the reactor water cleanup system to lower level without declaring an operation with a potential to drain the reactor vessel (OPDRV) without secondary containment operable. This condition is reportable to the NRC in accordance with 10 CFR 50.73(a)(2)(i)(B), as operations prohibited by Technical Specifications.
Summary of Commitments a'#-revisions to existing commitments.
This letter contains no new commitme
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0 Peter A. Ga er Site Vice President, Man
- ella N le r Generating Plant Northern States Power Company-Minnesota Enclosure cc:
Regional Administrator, Region Ill, USNRC Project Manager, Monticello Nuclear Generating Plant, USNRC Resident Inspector, Monticello Nuclear Generating Plant, USNRC
NRC FORM 366 (02-2014)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (02-2014)
LICENSEE EVENT REPORT (LER)
(See Page 2 for required number of digits/characters for each block)
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 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 />.
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Send comments regarding burden estimate to the FOIA, 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.
- 1. FACILITY NAME Monticello Nuclear Generating Plant
- 2. DOCKET NUMBER 05000-263
- 3. PAGE 1 of 4
- 4. TITLE Use of the Reactor Water Cleanup System to Lower Level without Declaring an Operation with a Potential to Drain the Reactor Vessel (OPDRV) with Secondary Containment Inoperable
- 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 DOCKET NUMBER 05000 05 14 2015 2015 -
003
- - 00 07 13 2015 FACILITY NAME DOCKET NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 5 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 0 %
20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)
OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Specify in Abstract below or in LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET during performance of these draining evolutions. Consequently, since SCT and the SGT System were inoperable during these occurrences, an operation or condition prohibited by the TS occurred.
SAFETY SIGNIFICANCE
The safety significance of these occurrences is minimal. Use of the RWCU System for draining operations is an operational function of the system. These types of evolutions are under the direct control of operations personnel. In accordance with TS 3.3.6.2, Secondary Containment Isolation Instrumentation, [JM] the Reactor Vessel Water Level - Low, Low isolation signal, is required to be operable when OPDRVs are being performed. If a reactor vessel draindown event through the RWCU System were to occur, this function automatically closes the appropriate valves terminating the event above the top of active fuel.
An Infrequently Performed Test or Evolution briefing was conducted with all participants for the reactor cavity and dryer-separator storage pool draindown evolution, which included requirements for monitoring water levels. Additionally, both the SGT System and SCT were available as mitigating systems.
During the periods on April 14 and 15, 2015, when water level was reduced using the RWCU System and the isolation valve was open, SCT and the B SGT subsystem were inoperable, and the valve would have closed, so the SGT subsystem fans would have exhausted sufficient flow to meet SR 3.6.4.1.4.
Therefore, while SCT and the B SGT subsystem were inoperable during this period, they were available.
CAUSE
A causal analysis is in progress for how the plant OPDRV procedure specified that use of the RWCU System for cleanup and inventory control activities was not considered an OPDRV. The cause will be provided in a supplement to this Licensee Event Report (LER).
CORRECTIVE ACTION
A corrective action is to revise the plant OPDRV procedure to correctly reflect the use of the RWCU System for draining evolutions as an OPDRV. This action is being tracked in the MNGP corrective action program.
PREVIOUS SIMILAR EVENTS
A review of MNGP LERs from the last three years was performed. During the 2015 Refueling Outage (RFO) several OPDRVs were performed that invoked the guidance of EGM 11-003, Revision 2, and were reported in LER 2015-001. This LER involves several additional OPDRVs for different situations where the guidance of EGM 11-003, Revision 2, was not invoked, and hence this LER is being submitted separately.
ADDITIONAL INFORMATION
The Institute of Electrical and Electronics Engineer codes for equipment are denoted by [XX].