05000237/LER-2019-001, Secondary Containment Differential Pressure Exceeded Technical Specification Due to Excess Ventilation Supply Flow
| ML19091A046 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/29/2019 |
| From: | Karaba P Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SVPLTR 19-0019 LER 2019-001-00 | |
| Download: ML19091A046 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(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)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 2372019001R00 - NRC Website | |
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4£> Exelon Generation SVPL TR# 19-0019 March 29, 2019 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 2 and 3 Renewed Facility Operating License Nos. DPR-19 NRC Docket No. 50-237 and 50-249 Dresden Nuclear Power Station 6500 North Dresden Road Morris, IL 60450 10 CFR 50.73
Subject:
Licensee Event Report 237/2019-001-00, Secondary Containment Differential Pressure Exceeded Technical Specification due to Excess Ventilation Supply Flow Enclosed is Licensee Event Report 237/2019-001-00, "Secondary Containment Differential Pressure Exceeded Technical Specification due to Excess Ventilation Supply Flow." This report describes an event which is being reported in accordance with 1 O CFR 50.73(a)(2)(v)(C), "Any event or condition that could have prevented the fulfillment of the safety function of... systems that are needed control the release of radioactive material."
There are no regulatory commitments contained in this submittal.
Should you have any questions concerning this letter, please contact Mr. Bruce Franzen at (815) 416-2800.
".!oe. Qvi1111.Q.r Peter J Karaba Site Vice President Dresden Nuclear Power Station Enclosure Licensee Event Report 237/2019-001-00 cc:
Regional Administrator-NRC Region Ill NRC Senior Resident Inspector - Dresden Nuclear Power Station
NRC FORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2018)
, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
3.Page Dresden Nuclear Power Station, Unit 2 05000237 1
OF 3
- 4. Title Secondary Containment Differential Pressure Exceeded Technical Specification due to Excess Ventilation Supply Flow
- 5. Event Date
- 6. LEA Number
- 7. Report Date
- 8. Other Facilities Involved I
Sequential I Rev Facility Name Docket Number Month Day Year Year Number No.
Month Day Year Dresden Unit 3 05000249 Facility Name Docket Number 01 30 2019 2019 -
001-00 03 29 2019 N/A 05000
- 9. Operating Mode
- 11. This Report is Submitted Pursuant to the Requirements of 10.CFR §: (Check all that apply)
D 20.2201 (bl D 20.2203(a)(3)(il D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A)
D 20.2201 (dl D 20.2203(a)(3)(iil D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B) 1 D 20.2203(aH1i D 20.2203(aH4l D so.13(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(il D 50.36(c)(1)(i)(A)
D 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x) 1 O. Power Level D 20.2203(a)(2)(iil D 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(v)(A)
D 13.11 (a)(4l D 20.2203(a)(2Hmi D so.36(c)(2l D 50.73(a)(2)(v)(B)
D 13.11 (aJ(si D 20.2203(a)(2)(iv)
D so.46(a)(3)(iil
~ 50.73(a)(2)(v)(C)
D 13.77(a)(1i 100 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(D)
D 13.11(a)(2)(i)
D 20.2203(a)(2)(vi)
D 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 13.77(aJ(2J(iil I:*>
.;;; -J.;' ';;
D 50.73(a)(2)(i)(C)
D other (Specify in Abstract below or in C.
Cause of Event
The cause of the event was determined to be inadequate procedural guidance for responding to loss of heating boilers during extreme cold external air temperatures.
D.
Safety Analysis
Except for the heating boilers pressure regulator prior to the event, all equipment responded as designed.
Operator action to start SBGT and to secure Unit 3 RB ventilation in accordance with procedure guidance prevented further degradation of the RB DP. Based on the Secondary Containment DP remaining negative during this event, the safety function of Secondary Containment was maintained, and this event is of low
safety significance
This event is being reported under 1 O CFR 50.73(a)(2)(v)(C), "Any event or condition that could have prevented the fulfillment of the safety function of... systems that are needed control the release of radioactive material."
E.
Corrective Actions
The operational response procedure for the loss of plant heating steam during extreme external air temperature conditions will be revised to prioritize Main Control Room operations to mitigate ventilation transients during a loss of heating boilers.
F.
Previous Occurrences
A previous event, Dresden LER 237/2016-001-00 on docket 50-237, was found during the investigation where a Secondary Containment DP transient followed a heating boiler shutdown. The Secondary Containment DP transient reported under this LER 2019-001-00 did not have the same causal factors.
G. Component Failure Data
Not applicable. Page_3_ of _3_