05000336/LER-2018-001, Regarding Loss of Both Trains of Control Room Emergency Ventilation Resulting in the Loss of Safety Function
| ML19022A263 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/19/2018 |
| From: | Daugherty J Dominion Energy Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 18-444 LER 2018-001-00 | |
| Download: ML19022A263 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(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)(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) |
| 3362018001R00 - NRC Website | |
text
I.
Dominion Energy Nuclear Connecticut, Inc.
Rt 156, Rope Ferry Road, Waterford, CT 06385 Dominion Energy.com U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION UNIT 2 LICENSEE EVENT REPORT 2018-001-00
"'1A Dominion j a,, Energy DEC 1 9 2018 Serial No.
MPS Lic/GJC Docket No.
License No.18-444 RO 50-336 DPR-65 LOSS OF BOTH TRAINS OF CONTROL ROOM EMERGENCY VENTILATION RESULTING IN THE LOSS OF SAFETY FUNCTION This letter forwards Licensee Event Report (LER) 2018-001-00 documenting a condition discovered at Millstone Power Station Unit 2, on October 23, 2018. This LER is being submitted pursuant to 10 CFR 50. 73(a)(2)(v)(D) as a condition that could have prevented the fulfillment of a safety function for systems or structures to mitigate the consequences of an accident.
If you have any questions or require additional information, please contact Mr. Jeffry A.
Langan at (860) 444-5544.
Sincerely, John R. Daugherty.
Site Vice President - Millstone Attachments: 1 Commitments made in this letter: None
cc:
U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd.
Suite 100 King of Prussia, PA 19406-2713 R.V. Guzman Serial No.18-444 Docket No. 50-336 Licensee Event Report 2018-001-00 Page 2 of 2 NRG Senior Project Manager Millstone Units 2 and 3 U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 08 C-2 Rockville, MD 20852-2738 NRG Senior Resident Inspector Millstone Power Station
ATTACHMENT Serial No.18-444 Docket No. 50-336 Licensee Event Report 2018-001-00 LICENSEE EVENT REPORT 2018-001-00 LOSS OF BOTH TRAINS OF CONTROL ROOM EMERGENCY VENTILATION RESULTING IN THE LOSS OF SAFETY FUNCTION MILLSTONE POWER STATION UNIT 2 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES:
03/31/2020 (04-2018)
, the NRC may not htti;i://www.nrc.gov/reading-nm/doc-collections/nuregs/staff/sr1022/r3/)
conduct or sponsor, and a person is not required to respond to, the infonmation collection.
3.Page Millstone Power Station Unit 2 05000336 1 OF 3
- 4. Title Loss of Both Trains of Control Room Emergency Ventilation Resulting in the Loss of Safety Function
- 5. Event Date
- 6. LER Number
- 7. Report Date
- 8. Other Facilities Involved Month Day Year Year I Sequential I Rev Month Day Year Facility Name Docket Number Number No.
05000 Docket Number 10 23 2018 2018.
001
. 00 12 19 18 05000
- 9. Operating Mode
- 11. This Report is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply)
D 20.2201(b)
D 20.2203(a)(3)(i)
D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A)
D 20.2201(d)
D 20.2203(a)(3)(ii)
D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B) 6 D
D D
D 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(iii)
- 50. 73(a)(2)(ix)(A)
D 20.2203(a)(2)(i)
D 50.36(c)(1 )(i)(A)
D 50.73(a)(2)(iv)(A)
D 50. 73(a)(2)(x)
- 10. Power Level D
20.2203(a)(2)(ii)
D 50.36(c)(1 )(ii)(A)
D 50.73(a)(2)(v)(A)
D 73.71 (a)(4)
D 20.2203(a)(2)(iii)
D 50.36(c)(2)
D 50.73(a)(2)(v)(B)
D 73,71(a)(5)
D 20.2203(a)(2)(iv)
D 50.46(a)(3)(ii)
D 50.73(a)(2)(v)(C)
D 73.77(a)(1) 0 D
20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A) 00 50.73(a)(2)(v)(D)
D 73.77(a)(2)(i)
D 20.2203(a)(2)(vi)
D 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 73.77(a)(2)(ii) i.*<;*s:;.. ~r>;
,:~ :,.,w
- \\.
- , i ;
'.( D 50.73(a)(2)(i)(C)
D Other (Specify in Abstract below or in APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 03/31/2020
, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 2. DOCKET YEAR 05000336 2018
- 3. LER NUMBER SEQUENTIAL NUMBER 001 REV NO.
00 The effects of degraded control room in-leakage on the control room habitability as the result of an accidental chemical release and smoke were also assessed. Specifically offsite propane rail car accidental release event and the on-site MPS3 carbon dioxide storage tank accidental release event. The assessment concluded the observed CRE in-leakage did not exceeded the maximum permissible air in-leakage limit for these types of releases and therefore the control room remained habitable.
4. CORRECTIVE ACTION
The degraded conditions that led to the test failure were corrected, and the control room air in-leakage test was re-performed satisfactorily. MPS maintenance, operations and testing procedures are being revised to improve maintenance and testing activities associated with CRE components. Additional corrective actions, including actions to strengthen the periodic assessment, are being taken in accordance with the station's corrective action program.
5. PREVIOUS OCCURRENCES
There are no previous occurrences with the same underlying reason or consequences.
- 6. Energy Industry Identification System (EIIS) codes VI - Control Building/Control DR-Door Page 3 of 3