05000412/LER-2009-001, Equipment Operability for Steam Generator Tube Rupture Safety Analysis Not Met
| ML092950343 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 10/15/2009 |
| From: | Harden P FirstEnergy Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-09-231 LER 09-001-00 | |
| Download: ML092950343 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii) 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)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(vi) |
| 4122009001R00 - NRC Website | |
text
FENOC FirstEnergy Nuclear Operating Company Beaver Valley Power Station P.O. Box 4 Shippingport, PA 15077 Paul A. Haiden Site Vice President October 15, 2009 L-09-231 724-682-5234 Fax: 724-643-8069 10 CFR 50.73 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 LER 2009-001-00 Attached is Licensee Event Report (LER) 2009-001-00, "Equipment Operability for Steam Generator Tube Rupture Safety Analysis Not Met." This event is being reported in accordance with 10 CFR 50.73(a)(2)(v)(C) and 50.73(a)(2)(v)(D).
There are no regulatory commitments contained in this submittal. Any actions discussed in this document that represent intended or planned actions are described for the NRC's information, and are not regulatory commitments.
If there are any questions or if additional information is required, please contact Mr. Colin P. Keller, Manager, Regulatory Compliance at 724-682-4284.
Attachment cc:
Mr. S..J. Collins, NRC Region I Administrator
.Mr. D. L. Werkheiser, NRC Senior Resident Inspector Ms. N. S. Morgan, NRR Project Manager INPO Records Center (via electronic image)
Mr. L. E. Ryan (BRP/DEP)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 08/31/2010 (9-2007)
, the NRC may sfor each block) not conduct or sponsor, and a person is not required to respond to, the digits/characters finformation collection.
- 3. PAGE Beaver Valley Power Station Unit Number 2 05000412 1 of 4
- 4. TITLE Equipment Operability for Steam Generator Tube Rupture Safety Analysis Not Met*
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO, MONTH DAY YEAR None 08 19 2009 2009 001 00 10 FACILITYNAME DOCKET NUMBER
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
[1 20.2201(b)
El 20.2203(a)(3)(i)
[I 50.73(a)(2)(i)(C)
E] 50.73(a)(2)(vii) 1[-]
20.2201 (d)
[] 20.2203(a)(3)(ii)
[:] 50.73(a)(2)(ii)(a)
[:] 50.73(a)(2)(viii)(A)
E] 20.2203(a)(1)
E] 20.2203(a)(4)
E] 50.73(a)(2)(ii)(B)
E] 50.73(a)(2)(viii)(B)
E] 20.2203(a)(2)(i)
[] 50.36(c)(1)(i)(A)
E] 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL
[] 20.2203(a)(2)(ii)
E] 50.36(c)(1)(ii)(A)
E] 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x)
E] 20.2203(a)(2)(iii)
E] 50.36(c)(2)
F] 50.73(a)(2)(v)(A)
El 73.71(a)(4) 100 %
[
20.2203(a)(2)(iv)
E] 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(B)
E] 73.71 (a)(5)
[
20.2203(a)(2)(v)
[
50.73(a)(2)(i)(A)
Z 50.73(a)(2)(v)(C)
Ej OTHER Specify in Abstract below 20.2203(a)(2)(vi)
~
50.73(a)(2)(i)(B) 50.73(a)(2)(V)(D) or in partitioning) is a safety function credited in the licensing basis safety analysis. In addition to meeting specified accident dose limits, a steam generator overfill condition was explicitly prohibited in the Nuclear Regulatory Commission's review of the current BVPS Unit 2 SGTR safety analysis (presumably since the aggregate consequences of steam generator overfill were not specifically assessed).
A review of BVPS Unit 2 equipment alignments over the last three years concluded that there was one prior occurrence when both the Train "A" EDG and one ADV were simultaneously not operable and unable to perform design functions for approximately ten hours on February 12, 2008. This condition violated the assumptions of the BVPS Unit 2 SGTR analysis of record. In this condition, BVPS Unit 2 was susceptible to a steam generator overfill which could not be mitigated in a timely fashion using safety related equipment, thus violating a BVPS Unit 2 licensing basis. The steam partitioning safety function,could have not been assured if a design basis SGTR event occurred with these two simultaneous out of service conditions. Thus, this was a condition that could have prevented the fulfillment of the safety function of a structure or system (without postulating any single failure) that are needed to: (C) Control the release of radioactive material; or (D)
Mitigate the consequences of an accident. Therefore, this is reportable pursuant to 10 CFR 50.73(a)(2)(v)(C) and 10 CFR 50.73(a)(2)(v)(D), consistent with 10 CFR 50.73(a)(2)(vi) which includes discovery of design/analysis inadequacies.
CAUSE OF EVENT
The root cause of this event was an inadequate design basis review during original plant design (legacy item) which resulted in minimal design capacity with respect to Steam Generator Tube Rupture overfill. Due to subsequently identified issues with this Steam Generator Tube Rupture overfill analysis, it was realized that it was necessary to rely on cross-train components to meet safety analyses assumptions.
Contributing Causes were: 1) previous engineering review processes did'not contain-sufficient rigor to identify this loss of a safety function; 2) procedures for on-line risk assessment and management (1/2-ADM-0804) and Technical Specification compliance (1/20M-48.1.1) did not include the prohibition for concurrent removal of this equipment, and.
- 3) personnel developing and reviewing engineering documents focused on the standard engineering parameter of a single failure being mitigated by a complete available train of equipment instead of relying on cross train components to satisfy safety function.
ANALYSIS OF EVENT
The plant risk associated with the BVPS Unit 2 unanalyzed potential steam generator overfill conditions resulting from a Steam Generator Tube Rupture concurrent with a Loss of Offsite Power durinq the last three year period time frame when both an "A" Train EDG
and an ADV were inoperable, is considered to be very low. The plant configurations that resulted in these potential steam generator overfill conditions were assessed using the BVPS Configuration Risk Management Program. The safety significance of these plant configurations is very low based on the relatively short durations and analyzed Incremental Core Damage Probability (ICDP) and Incremental Large Early Release Probability (ILERP). Furthermore, there was a low probability of having a steam generator overfill event during the periods while in these configurations.
CORRECTIVE ACTIONS
- 1. A standing Operations order was promptly issued to prohibit voluntarily removing one EDG and one ADV from service concurrently.
- 2. Theaffected site procedures have been revised to alert Work Planning and Operations /
Control Room personnel that the "A" Train Emergency Diesel Generator and any Atmospheric Steam Dump Valve at Unit 2 cannot be removed from service concurrently.
- 3. The engineering interface process will be strengthened by clarifying the specific requirements involving explicit use of cross-train components. This will minimize the potential for rule or knowledge based errors.
- 4. An extent of condition review determined that a similar condition also applies to BVPS Unit 1. [Note: the specific adverse configuration was not entered at BVPS Unit 1 within the last three years and is not reportable.] The same limitations on not taking one Train "A" EDG out of service coincident with one ADV at BVPS Unit 2 will also be applied to BVPS Unit 1.
- 5. An additional extent of cause will be performed for safety analyses which may require components of opposite trains to satisfy a safety function.
- 6. An Operating Experience report (No. 29759) has been issued on this issue.
Completion of the above and other corrective actions are being tracked throughthe BVPS corrective action program.
PREVIOUS SIMILAR EVENTS
A review found no prior BVPS Unit No. 1 or prior BVPS Unit No. 2 Licensee Event Reports within the last three years for an event involving a design basis safety analysis deficiency.
CR 09-63451