05000390/LER-2006-007, Regarding High Range Radiation Monitors - Temperature Induced Current

Regarding High Range Radiation Monitors - Temperature Induced Current

ML062630321
Person / Time
Site:	Watts Bar
Issue date:	09/18/2006
From:	Skaggs M Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 06-007-00
Download: ML062630321 (7)

LER-2006-007, Regarding High Range Radiation Monitors - Temperature Induced Current

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(v), Loss of Safety Function 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)
3902006007R00 - NRC Website

text

10 CFR 50.73 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Gentlemen:

In the Matter of

)

Docket No. 50-390 Tennessee Valley Authority

)

WATTS BAR NUCLEAR PLANT (WBN) UNIT 1 - LICENSEE EVENT REPORT 390/2006-007 - HIGH RANGE RADIATION MONITORS - TEMPERATURE INDUCED CURRENTS On August 4, 2006, TVA provided a report which documented an issue involving temperature induced current which affects the high range radiation monitors. This condition is also reportable under 10 CFR 50.73(a)(2)(i)(B). This submittal provides LER 390/2006-007.

Should there be questions regarding this submittal, please contact Paul L. Pace at (423) 365-1824.

Sincerely, Mike Skaggs Enclosure cc: See Page 2 September 18, 2006 Original signed by

U.S. Nuclear Regulatory Commission Page 2 Enclosure cc (Enclosure):

NRC Resident Inspector Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 Mr. D. V. Pickett, Senior Project Manager U.S. Nuclear Regulatory Commission MS 08G9a One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 Institute of Nuclear Power Operations 700 Galleria Parkway, NW Atlanta, Georgia 30339-5957 September 18, 2006

LICENSEE EVENT REPORT (LER)

NRC FORM 366 (6-2004)

U.S. NUCLEAR REGULATORY COMMISSION

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

APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 (See reverse for required number of digits/characters for each block) 1 OF

3. PAGE 05000

4. TITLE

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 05000 DOCKET NUMBER FACILITY NAME 05000 DOCKET NUMBER

9. OPERATING MODE

10. POWER LEVEL

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 20.2201(b) 20.2201(d) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(2)(v) 20.2203(a)(2)(vi) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.36(c)(1)(i)(A) 50.36(c)(1)(ii)(A) 50.36(c)(2) 50.46(a)(3)(ii) 50.73(a)(2)(i)(A) 50.73(a)(2)(i)(B) 50.73(a)(2)(i)(C) 50.73(a)(2)(ii)(A) 50.73(a)(2)(ii)(B) 50.73(a)(2)(iii) 50.73(a)(2)(iv)(A) 50.73(a)(2)(v)(A) 50.73(a)(2)(v)(B) 50.73(a)(2)(v)(C) 50.73(a)(2)(v)(D) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B)

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)Watts Bar Nuclear Plant, Unit 1 390 2006 007 00 5

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VII. ADDITIONAL INFORMATION

A. Failed Components There were no failed components due to this condition.

B. Previous LERs on Similar Events A review performed of the previous WBN Licensee Event Reports (LERs) for any events associated with high range radiation monitor reliability did reveal any previous issues.

C. Additional Information

None.

D. Safety System Functional Failure This event did not involve a safety system functional failure as defined in NEI 99 02, Revision 4.

E. Loss of Normal Heat Removal Consideration There was no loss of normal heat removal due to this condition.

VIII. COMMITMENTS

A modification is planned to replace the affected cables with cables that minimize the TIC phenomenon. The modification will allow the radiation monitors to function within their required accuracy and within acceptable limits throughout the post accident period. This design change will be implemented in the Cycle 8 refueling outage which is scheduled for early 2008.

Prior to that implementation, walkdowns are required in the Cycle 7 refueling outage to obtain measurements for cable lengths and identify required raceway modifications. Therefore, the Cycle 8 refueling outage is the first reasonable outage of sufficient duration to implement the change after the required material has been purchased and staged.