05000261/LER-2011-001-01, Regarding Condition Prohibited by Technical Specifications When Non-Seismic System Was Aligned to Refueling Water Storage Tank Due to Regulatory Requirements Not Adequately Incorporated in Plant Documentation
| ML12228A384 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 08/10/2012 |
| From: | Progress Energy Carolinas |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| RNP-RA/12-0082 LER 11-001-01 | |
| Download: ML12228A384 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2612011001R01 - NRC Website | |
text
United States Nuclear Regulatory Commission Attachment I to Serial: RNP-RA/12-0082 4 Pages (including cover page)
H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 LER 2011-001-01, CONDITION PROHIBITED BY TECHNICAL SPECIFICATIONS WHEN NON-SEISMIC SYSTEM WAS ALIGNED TO REFUELING WATER STORAGE TANK DUE TO REGULATORY REQUIREMENTS NOT ADEQUATELY INCORPORATED IN PLANT DOCUMENTATION
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSIONk.
- AIiPPROVED BY OMB
- ' NO: 150-0104 EXPIRES 10/3112013 (10-2010)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE H. B. Robinson Steam Electric Plant, Unit No. 2 05000261 1
1 OF 3
- 4. TITLE Condition Prohibited by Technical Specifications When Non-Seismic System was Aligned to Refueling Water Storage Tank due to Regulatory Requirements not Adequately Incorporated in Plant Documentation
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER M O N T H D A Y Y E A R Y E A R S E Q U E N T IA L R E V M O N T H D A Y Y E A R 0 5 0 0 0 NUMBER NO MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 05 04 2011 2011 001 01 08 01 2012 05000
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
- 9. OPERATING MODE 2O 20.2201(b)
El 20.2203(a)(3)(i) rl 50.73(a)(2)(i)(c)
E]
50.73(a)(2)(vii) f-20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A) fl 50.73(a)(2)(viii)(A) 1 fl 20.2203(a)(1)
El 20.2203(a)(4)
[I 50.73(a)(2)(ii)(B) f-50.73(a)(2)(viii)(B) 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii) j]
50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A) fl 50.73(a)(2)(x)
[]
20.2203(a)(2)(iii)
E]
50.36(c)(2)
[3 50.73(a)(2)(v)(A)
El 73.71(a)(4) 100%
El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
E]
73.71 (a)(5) fl 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
[]
OTHER Specify in Abstract below l
20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B) 0 50.73(a)(2)(v)(D) or in Report (UFSAR).
IV. SAFETY SIGNIFICANCE
The risk impact of having the RWST aligned for purification has been evaluated and determined to be of low risk impact (<5E-07). This analysis takes into consideration the impact of internal flooding due to a pipe break, as well as the increase in risk due to a seismic event. The result of the analysis was based on having the non-seismic refueling water purification loop in service aligned to the RWST with the plant on-line for a conservative estimate of approximately 5000 hours0.0579 days <br />1.389 hours <br />0.00827 weeks <br />0.0019 months <br /> per year. The analysis conservatively assumed that the refueling water purification path will fail and drain the RWST under a range of seismic events. Also, operator actions are conservatively not credited after a break in the purification flowpath. Even with these conservative assumptions, having the RWST in recirculation mode while the plant is at power results in a very small increase in risk due to seismic events.
The condition described in this Licensee Event Report is reportable in accordance with the following: 10 CFR 50.73(a)(2)(i)(B), any operation or condition which was prohibited by the plant's Technical Specifications. 10 CFR 50.73(a)(2)(v)(D), Event or Condition that could have prevented fulfillment of a safety function. For purposes of Safety System Functional Failures (SSFF) reporting, this constitutes three (3) SSFFs as there were three events in the 12 months prior to LER 2011-001-00, May 4, 2011.
These events are historical and are not included in the current reporting of SSFF. The change file for SSFF data has been submitted for these.
V. CORRECTIVE ACTIONS
Completed Corrective Actions:
Administrative controls have been put in place to provide guidance for Operations on alignment restrictions for piping that could affect the operability of the RWST.
Planned Corrective Actions
Applicable Operations procedures will be revised to restrict alignment of the refueling water purification loop to periods when RWST operability is not required.
" Applicable sections of the UFSAR and Design Basis Documentation will be revised to include restrictions on the operating modes when the purification loop is allowed to be used to purify the RWST.
VI. PREVIOUS SIMILAR EVENTS
Licensee Event Reports (LERs) for HBRSEP, Unit No. 2, were reviewed from the past 5 years. No similar events were identified.