05000321/LER-2014-004, Regarding Non-Functional Penetrations Compromise Safe Shutdown Paths in Postulated Fire Event
| ML14206B133 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 07/25/2014 |
| From: | Pierce C Southern Co, Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-14-1092 LER 14-004-00 | |
| Download: ML14206B133 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 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)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2) 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 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3212014004R00 - NRC Website | |
text
Charles R. Pierce Regulatory Affairs Director July 25, 2014 Docket Nos.: 50-321 50-366 Southern Nuclear Operating Company, Inc.
40 Inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205.992.7872 Fax 205.992.7601 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Licensee Event Report 2014-004-00 NL-14-1 092 Non-Functional Penetrations Compromise Safe Shutdown Paths in Postulated Fire Event Ladies and Gentlemen:
In accordance with the requirements of 10 CFR 50.73(a)(2)(ii)(B) Southern Nuclear Operating Company hereby submits the enclosed Licensee Event Report.
This letter contains no NRC commitments. If you have any questions, please contact Greg Johnson at (912) 537-587 4.
Respectfully submitted, Cf{~
C. R. Pierce Regulatory Affairs Director CRP/mar Enclosure: LER 2014-004-00
U.S. Nuclear Regulatory Commission NL-14-1092 Page2 cc:
Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Best, Executive Vice President & Chief Nuclear Officer Mr. D. R. Vineyard, Vice President-Hatch Mr. B. L. lvey, Vice President-Regulatory Affairs Mr. D. R. Madison, Vice President-Fleet Operations Mr. B. J. Adams, Vice President-Engineering Mr. G. L. Johnson, Regulatory Affairs Manager-Hatch RTYPE: CHA02.004 U.S. Nuclear Regulatory Commission Mr. V. M. McCree, Regional Administrator Mr. R. E. Martin, NRR Senior Project Manager-Hatch Mr. D. H. Hardage, Senior Resident Inspector-Hatch
NRCFORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 315~104 EXPIRES: 01131/2017 (02*2014)
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Estimated burden per response to comply v.ith 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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Reported lessons lesmed are Incorporated Into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and lnfonnation CoUections
\\-....... i LICENSEE EVENT REPORT (LER)
Branch (T*5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by Internet e-mail to lnfocollects.Resouroe@nro.g(71f, and to the Desk Officer, Office of Information and (See Page 2 for required number of Regulatory Affairs, NEOB-10202, (315().()104), Office of Management and Budget, Washington, DC digits/characters for each block) 20503. II a means used to impose an infonnation collection dces not display a cunently valid OMB control number, the NRC may not conduct or sponsor, and a person is not requinsd to respond to, the lnfonnation collection.
- 3. PAGE Edwin I. Hatch Nuclear Plant Unit 1 05000 321 1 OF 3
- 4. TITLE Non-Functional Penetrations Compromise Safe Shutdown Paths in Postulated Fire Event
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED YEAR I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO.
MONTH DAY YEAR Edwin I. Hatch Nuclear Plant Unit 2 05000 366 FACILITY NAME DOCKET NUMBER 05 29 2014 2014 - 004 -
00 07 25 2014
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 0 20.2201(b) 0 20.2203(a)(3)(i) 0 50.73(a)(2)(i)(C) 0 50.73(a)(2)(vii)
Mode 1 0 20.2201(d) 0 20.2203(a)(3)(ii) 0 50.73(a)(2)(ii)(A) 0 50.73(a)(2)(viii)(A) 0 20.2203(a)(1) 0 20.2203(a)(4)
~ 50.73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B) 0 20.2203(a)(2)(i) 0 50.36(c)(1 )(i)(A) 0 50.73(a)(2)(iii) 0 50.73(a)(2)(1x)(A)
- 10. POWER LEVEL 0 20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x) 0 20.2203(a)(2)(iii) 0 50.36(c)(2) 0 50.73(a)(2)(v)(A) 0 73.71(a)(4) 100 0 20.2203(a)(2)(1v) 0 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(B) 0 73.71(a)(5) 0 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(C) 0 OTHER 0 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B) 0 50.73(a)(2)(v)(D)
Specify in Abstract below or In
PLANT AND SYSTEM IDENTIFICATION
General Electric - Boiling Water Reactor YEAR 2014
- 6. LER NUMBER I SEQUENTIAL I NUMBER 004 Energy Industry Identification System codes appear in the text as (EllS Code XX).
DESCRIPTION OF EVENT
REV NO.
00 2
- 3. PAGE OF On May 29, 2014, at approximately 1633 EDT, Unit 1 and Unit 2 were operating at 100 percent rated thermal power (RTP) when an analysis was completed by corporate risk informed engineering identifying that both safe shutdown paths were compromised during a postulated fire event. The analysis was performed in light of a discovery that some fire penetration seal configurations do not correspond to a tested configuration. Due to the un-tested configuration of these seals, the penetrations were declared non-functional. In their current state, non-tested fire penetration seals result in degraded barriers that could compromise both safe shutdown paths during a postulated fire.
3 In July 2013, the fire penetration inspection began and starting on 9/13/2013 several penetration seals were identified as potentially non-conforming due to the presence of grout instead of the seal material shown on the design drawings. Fire watches were established due to the presence of the non-conforming conditions. Work orders were created to repair the affected fire barrier penetration seals to return them to the condition called for by the design drawings. Upon start of the repair of the affected penetration seals, two were found to contain grout filled 1.5 inches or less into the penetration. In 2014, upon further investigation, some fire penetration seals that were found to have 1.5 inches or less of grout were also found to be in concrete masonry walls that contained hollow cell columns.
The affected penetration seals are located in the Control Building. Two out of three consecutive cell columns in these concrete masonry walls are hollow. The remaining cell is filled with grout which is non-shrinkable. SNC calculations conclude that most walls in the control building exceed the requirements for even the heaviest of aggregates for a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire rating. However fire penetrations that are in hollow columns, with 1.5 inches of grout seal, do not meet a configuration that has been tested and therefore currently do not meet 10 CFR 50 Appendix R requirements.
CAUSE OF EVENT
The cause of the event is attributed to not maintaining adequate configuration control of the fire penetration seals through hollow walls. The point at which this occurred could not be determined and is considered a legacy issue.
Current processes will ensure that the configuration of the penetrations through hollow brick walls will be maintained.
REPORT ABILITY ANALYSIS AND SAFETY ASSESSMENT Since the vulnerability described could result in a condition such that the required degree of separation for redundant safe shutdown trains would be adversely impacted, this event represents an unanalyzed condition that significantly degrades plant safety and is reportable in accordance with 10 CFR, Part 50.73(a)(2)(ii)(B). (02-2014)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE OF YEAR J SEQUENTIAL I REV NUMBER NO.
Edwin I. Hatch Nuclear Plant Unit 1 05000 321 3
3 2014 004 00 The "as found" configuration of 1.5 inches of grout, or less, used to seal the penetrations of the hollow block walls, does not currently meet Appendix R requirements. This configuration represents a degraded condition, since the use of grout in this manner does not constitute a tested configuration. However, the presence of the fire wall, although degraded, continues to provide a barrier in conjunction with defense in depth measures that include adequate fire detection and fire suppression systems. These engineered features provide sufficient delay so that in the event of a postulated fire, there will be adequate time for the response of the station fire brigade to take appropriate actions to mitigate the consequences of a fire to ensure at least one safe shutdown path is preserved. This is a postulated event and as such did not adversely affect the safe operation of the plant or the safety of the public. The actual safety impact of this condition has very low safety significance.
CORRECTIVE ACTIONS
Fire watches were established as compensatory measures during the planned testing of the "as found" configuration of the penetrations and will continue as required until the configurations have been determined to meet 10 CFR 50 Appendix R requirements in their "as found" state or until the repair phase of the penetrations has been completed.
Planned corrective actions include:
- Walk down and inspection of 100 percent of the affected fire penetration seals is planned to be completed by April 2016. Any needed repairs or design drawing updates may be performed as required.
- Testing of non-conforming fire penetration seal configurations to determine if 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire rating is met is planned to be completed by October 2014. Updates to drawings and calculations may be performed, based on results achieved.
- Provide a corrective action plan for additional corrective actions based on the results of the penetration testing.
These corrective actions will be updated, as appropriate, upon completion of this testing.
ADDITIONAL INFORMATION
Other Systems Affected: None
Failed Components Information
Master Parts List Number: Multiple Fire Barrier Penetrations Manufacturer: N/A Model Number: N/A Type: Fire Barrier Penetration Manufacturer Code: N/A EllS System Code: NA Reportable to EPIX: Y Root Cause Code: X EllS Component Code: PEN Commitment Information: This report does not create any licensing commitments.
PREVIOUS SIMILAR EVENTS
None