ML071230268

Submittal of Changes to Technical Specification Bases

ML071230268
Person / Time
Site:	Three Mile Island
Issue date:	04/27/2007
From:	David Helker AmerGen Energy Co
To:	Document Control Desk, NRC/NRR/ADRO
References
5928-07-20100
Download: ML071230268 (2)

Text

AmerGen Energy Company, LLC www.exe]oncorp.com Amer An Exelon Company 2o0 Exelon Way Kennett Square, PA 19348 TS 6.18.d 5928-07-20100 April 27, 2007 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Three Mile Island, Unit 1 Facility Operating License No. DPR-50 NRC Docket No. 50-289

Subject:

Submittal of Changes to Technical Specifications Bases In accordance with the requirement of Three Mile Island, Unit 1 Technical Specification 6.18.d, Bases changes implemented without NRC approval shall be submitted to the NRC. Since last year's submittal, one (1) Bases change has occurred through the date of this letter. The revised page is attached.

If you have any questions or require further information, please contact Tom Loomis (610-765-5510).

Sincerely, David P. Helker Manager - Licensing & Regulatory Affairs Attachment cc: S. J. Collins, Administrator, Region 1, USNRC D. M. Kern, USNRC Senior Resident Inspector P. Bamford, Project Manager, USNRC File No. 07030 UIN 74-*,ý

d. The battery will be subjected to a load test on a refueling interval basis.

(1) Verify battery capacity exceeds that required to meet design loads.

(2) Any battery which is demonstrated to have less than 85% of manufacturers ratings during a capacity discharge test shall be replaced during the subsequent refueling outage.

4.6.3 Pressurizer Heaters

a. The following tests shall be conducted at least once each refueling:

(1) Pressurizer heater groups 8 and 9 shall be transferred from the normal power bus to the emergency power bus and energized. Upon completion of this test, the heaters shall be returned to their normal power bus.

(2) Demonstrate that the pressurizer heaters breaker on the emergency bus cannot be closed until the safeguards signal is bypassed and can be closed following bypass.

(3) Verify that following input of the Engineered Safeguards Signal, the circuit breakers, supplying power to the manually transferred loads for pressurizer heater groups 8 and 9, have been tripped.

Bases The tests specified are designed to demonstrate that one diesel generator will provide power for operation of safeguards equipment. They also assure that the emergency generator control system and the control systems for the safeguards equipment will function automatically in the event of a loss of normal a-c station service power or upon the receipt of an engineered safeguards Actuation Signal. The intent of the monthly tests is to demonstrate the diesel capability to carry design basis accident (LOOP/LOCA) load. The test should not exceed the diesel 2000-hr. rating of 3000 kW. The automatic tripping of manually transferred loads, on an Engineered Safeguards Actuation Signal, protects the diesel generators from a potential overload condition. The testing frequency specified is intended to identify and permit correction of any mechanical or electrical deficiency before it can result in a system failure. The fuel oil supply, starting circuits, and controls are continuously monitored and any faults are alarmed and indicated. An abnormal condition in these systems would be signaled without having to place the diesel generators on test.

Precipitous failure of the station battery is extremely unlikely. The surveillance specified is that which has been demonstrated over the years to provide an indication of a cell becoming unserviceable long before it fails.

The PORV has a remotely operated block valve to provide a positive shutoff capability should the relief valve become inoperable. The electrical power for both the relief valve and the block valve is supplied from an ESF power source to ensure the ability to seal this possible RCS leakage path.

The requirement that a minimum of 107 kw of pressurizer heaters and their associated controls be capable of being supplied electrical power from an emergency bus provides assurance that these heaters can be energized during a loss of offsite power condition to maintain natural circulation.

4-47 Amendment No. 78, 157, 167, 175, ECR TM 07-00119