05000296/LER-2007-001, Regarding Reactor Scram Due to Low Reactor Water Level Caused by Loss of Feedwater

Regarding Reactor Scram Due to Low Reactor Water Level Caused by Loss of Feedwater

ML071010442
Person / Time
Site:	Browns Ferry
Issue date:	04/10/2007
From:	O'Grady B Tennessee Valley Authority
To:	Document Control Desk, NRC/NRR/ADRO
References
LER 07-001-00
Download: ML071010442 (9)

LER-2007-001, Regarding Reactor Scram Due to Low Reactor Water Level Caused by Loss of Feedwater

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(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
2962007001R00 - NRC Website

text

April 10, 2007 U.S. Nuclear Regulatory Commission 10 CFR 50.73 ATTN: Document Control Desk Mail Stop OWFN, P1-35 Washington, D. C. 20555-0001

Dear Sir:

TENNESSEE VALLEY AUTHORITY - BROWNS FERRY NUCLEAR PLANT (BFN) -

UNIT 2 - DOCKET 50-296 - FACILITY OPERATING LICENSE DPR LICENSEE EVENT REPORT (LER) 50-296/2007-001-00 The enclosed report provides details of a Unit 3 automatic scram due to a low reactor water level caused by a loss of feedwater.

In accordance with 10 CFR 50.73 (a) (2) (iv) (A), TVA is reporting this event as a valid actuation of the reactor protection system and containment isolation valves in more than one system, actuation of emergency core cooling systems including high-pressure coolant injection system and reactor core cooling system. There are no commitments contained in this letter.

Sincerely, Original signed by:

Brian O'Grady cc: See page 2

U.S. Nuclear Regulatory Commission Page 2 April 10, 2007 Enclosure cc (Enclosure):

Ms. Eva Brown, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)

One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Ms Margaret H. Chernoff, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)

One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Mr. Malcolm T. Widmann, Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970

U.S. Nuclear Regulatory Commission Page 3 April 10, 2007 WDC:DTL:SWA:BAB Enclosure cc (Enclosure):

M. Bajestani, NAB 1A-BFN A. S. Bhatnagar, LP 6A-C R. H. Bryan, BR 4X-C R. G. Jones, POB 2C-BFN G. V. Little, NAB 1D-BFN B. J. O'Grady, PAB 1E-BFN R. A. DeLong, SAB 1E-BFN P. D. Swafford, LP 6A-C E. J. Vigluicci, WT 6A-K NSRB Support, LP 5M-C INPO:LEREvents@inpo.org EDMS WT CA - K S:lic/submit/lers/296-2007-001.doc

NRC FORM 366 (6-2004)

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (6-2004)

LICENSEE EVENT REPORT (LER)

(See reverse for required number of digits/characters for each block)

APPROVED BY OMB NO. 3150-0104 EXPIRES 06/30/2007

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

1. FACILITY NAME Browns Ferry Unit 3

2. DOCKET NUMBER 05000296

3. PAGE 1 OF 6

4. TITLE Reactor Scram Due To Low Reactor Water Level Caused By Loss Of Feedwater.

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.

MONTH DAY YEAR FACILITY NAME none DOCKET NUMBER N/A 02 09 2007 2007-001-00 04 10 2007 FACILITY NAME none DOCKET NUMBER N/A

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §:(Check all that apply)

9. OPERATING MODE 1

20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A)

X 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)

OTHER

10. POWER LEVEL 100 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D) specify in Abstract below or in (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17) VI. CORRECTIVE ACTIONS A.

Immediate Corrective Actions

Reactor Scram Operations placed the reactor in a stable condition according to plant procedures.

Restart of Recirculation Pumps Operations entered TS LCO 3.4.9.A1 and A2 which requires that an engineering evaluation be performed within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to determine if the reactor coolant system (RCS) is acceptable for continued operation. The evaluation found the RCS acceptable for continued operation.

B.

Corrective Actions to Prevent Recurrence(1)

• TVA is revising the operating instructions for the condensate demineralizer system to include manual operation.

• TVA is revising trouble shooting guidance to eliminate trouble shooting under the direction of the system engineer or other individuals except under tightly controlled circumstances.

VII.

ADDITIONAL INFORMATION

A.

Failed Components None.

B.

Previous LERs on Similar Events None.

C.

Additional Information

The corrective action document for the reactor scram is PER 119490. The recirculation pump start issue is discussed in corrective action document PER 119489.

D.

Safety System Functional Failure Consideration:

No safety functions were compromised as a result of this event. Therefore, this event is not considered a safety system functional failure in accordance with NEI 99-02 in that functional capability of the overall system was maintained.

E.

Loss of Normal Heat Removal Consideration:

The main condenser and feedwater system provided a normal heat removal path following the reactor scram. Accordingly, this event did not result in a scram with a loss of normal heat removal as defined in NEI 99-02.

VIII.

COMMITMENTS

None.

(1) TVA does not consider these corrective actions regulatory commitments. The completion of these actions will be tracked in TVAs Corrective Action Program.