05000282/LER-2012-001, Regarding Non-Conservation Calculation of Diesel Fuel Storage Requirements
| ML12107A032 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/12/2012 |
| From: | Schimmel M Northern States Power Co, Xcel Energy |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-PI-12-025 LER 12-001-00 | |
| Download: ML12107A032 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 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)(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) 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 2822012001R00 - NRC Website | |
text
April 12, 2012 L-PI-12-025 10 CFR 50.73 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Unit 1 Docket: 50-282 Renewed License No. DPR-42 LER 50-2821201 2-001 -00, Non-Conservative Calculation Of Diesel Fuel Storage Requirements Northern States Power Company, a Minnesota corporation (NSPM), doing business as Xcel Energy, herewith encloses Licensee Event Report (LER) 50-28212012-001-00.
On February 15, 2012, a reportability review was completed regarding an error identified in the pre-operation test records for the Unit 1 diesel generators (Dl and D2).
The error, along with the subsequent discovery of an additional error regarding fuel oil energy content assumptions, affected the fuel oil storage calculation, which increased the volume of stored diesel fuel required to operate D l or D2 and a diesel-driven cooling water pump for 14 days in the event of a postulated maximum probable flood. A review using the corrected values determined that for a single period of up to 738 continuous hours and 2202 total hours in 2010 the revised requirements were not met, rendering D l and D2 inoperable.
Compensatory measures were updated to ensure a minimum 14-day supply of diesel fuel oil until a previously submitted Technical Specification amendment to revise LCOs 3.7.8 and 3.8.3 is approved.
Summaw of Commitments This letter contains no n no changes to existing commitments.
Mark A. Schimmel Site Vice President, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota 171 7 Wakonade Drive East Welch, Minnesota 55089-9642 Telephone: 651.388.1 121
Document Control Desk Page 2 Enclosure cc:
Administrator, Region Ill, USNRC Project Manager, Prairie Island Nuclear Generating Plant (PINGP), USNRC Resident Inspector, PINGP, USNRC Department of Commerce, State of Minnesota
ENCLOSURE LICENSEE EVENT REPORT 50-28212012-001-00 3 Pages Follow
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (1 0-201 0)
LICENSEE EVENT REPORT (LER)
(See!everse for re uired number of d~g~tslcharacters?or each block)
- 1. FACILITY NAME Prairie Island Nuclear Generating Plant APPROVED BY OMB NO. 3150-0104 EXPIRES 1013112013
, the NRC may not conduct or sponsor, and a person IS norrequired to respond to, the information collection.
- 2. DOCKET NUMBER 05000 - 282
- 4. TITLE Non-Conservative Calculation Of Diesel Fuel Storage Requirements
- 3. PAGE 1 OF 3
- 8. OTHER FACILITIES INVOLVED
- 9. OPERATING MODE 1
- 10. POWER LEVEL 100%
FACILITY NAME FACILITY NAME
- 7. REPORT DATE
- 5. EVENT DATE
- 11. THlS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 5: (Check all that apply)
[7 20.2201(b) 20.2203(a)(3)(i) 50,73(a)(2)(i)(C)
[XI 50.73(a)(2)(vii)
[7 20.2201(d) 20.2203(a)(3)(ii) 50,73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(I) 20.2203(a)(4) 50,73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 171 20.2203(a)(2)(i) 50.36(c)(l)(i)(A) 50.73(a)(2)(iii) 50,73(a)(2)(ix)(A) 20.2203(a)(2)(ii)
[7 50.36(c)(l)(ii)(A)
[7 50,73(a)(2)(iv)(A) 50.73(a)(2)(x) 171 20.2203(a)(2)(iii) 50.36(~)(2) 50.73(a)(2)(v)(A)
[7 73.71 (a)(4) 20.2203(a)(2)(iv) 17 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 171 73.71 (a)(5) 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A) 50.73(a)(2)(~)(~)
OTHER Specify in Abstract below or in 20.2203(a)(2)(vi)
[XI 50.73(a)(2)(i)(B)
IE3 50.73(a)(2)(v)(D) 2. DOCKET 05000 - 282
- 6. LER NUMBER YEAR 2012 -
001 -
00 SEQUENTIAL NUMBER REV NO.
On February 15, 2012, with Unit 1 in Mode 1 at 100% power, a reportability review was completed, It determined that this event was reportable under 10 CFR 50.73(a)(2)(i)(B) as an operation or condition prohibited by TS. In addition, the event is reportable under 10 CFR 50.73(a)(2)(vii) as a common-cause inoperability of independent trains or channels and 10 CFR 50.73(a)(2)(v)(D), an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. (10-2010)
The causal evaluation determined that calculation errors that resulted in non-conservative requirements for TS LCOs 3.7.8 and 3.8.3 were caused by a lack of technical rigor in the design process.
The minimum available fuel oil during the periods of inoperability was approximately 64,630 gallons without crediting day tank volumes, compared to the required 67,370.76 gallons. Although not available to be credited during a plant screenhouse internal flooding event at the time, two safety-related diesel-driven cooling water pump storage tanks were also available. The stored diesel fuel in either tank, in addition to the diesel fuel credited in the four Design Class I fuel oil storage tanks, would have been sufficient to meet the revised requirements. As a result, there were no radiological, environmental or industrial impacts associated with this event. Therefore, this event did not affect the health and safety of the public.
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET I CORRECTIVE ACTIONS I
U.S. NUCLEAR REGULATORY COMMISSION
- 1. FACILITY NAME Prairie Island Nuclear Generating Plant I
A major revision to ENG-ME-020 will be completed, which requires all design inputs to be verified. I Compensatory measures were updated to ensure a minimum 14-day supply of diesel fuel oil until a previously submitted Technical Specification amendment to revise LCOs 3.7.8 and 3.8.3 is approved.
- 2. DOCKET 05000 - 282 No similar licensee event reports at the Prairie Island Nuclear Generating Plant involving calculation errors leading to non-conservative Technical Specifications were identified in the past three years. 3. PAGE 3 OF 3
- 6. LER NUMBER YEAR 2012 -
001 -
00 SEQUENTIAL NUMBER REV NO.