B17818, Provides NRC Staff with Change to TS Bases Sections 3/4.5.2 & 3/4.5.3, ECCS Subsystems for Info Only.Change Was Reviewed & Approved by Unit 3 Plant Operations Review Committee IAW Provisions of 10CFR50.59

Provides NRC Staff with Change to TS Bases Sections 3/4.5.2 & 3/4.5.3, ECCS Subsystems for Info Only.Change Was Reviewed & Approved by Unit 3 Plant Operations Review Committee IAW Provisions of 10CFR50.59

ML20210D204
Person / Time
Site:	Millstone
Issue date:	07/16/1999
From:	Necci R NORTHEAST NUCLEAR ENERGY CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20210D209	List: B17818, Provides NRC Staff with Change to TS Bases Sections 3/4.5.2 & 3/4.5.3, ECCS Subsystems for Info Only.Change Was Reviewed & Approved by Unit 3 Plant Operations Review Committee IAW Provisions of 10CFR50.59 ML20210D212
References
B17818, NUDOCS 9907270150
Download: ML20210D204 (2)

Text

4 4

]

'.~a .

=

Northeast Rope Ferry Rd. (Route 156), Eterford, CT 06385 Nuclear Energy uiii ,,,, y,ci,,, p ,,, g,,,io,

. Northeast Nuclear Energy Company P.O. Box 128 Waterford, CT 06385-0128 (860) 447-1791 Faz (860) 444-4277 The Northeast Utihties System JUL i 61999 Docket No. 50-423 B17818 Re: 10CFR50.59 U.S. Nuclear Regulatory Commission Attention: Document Control Desk l Washington, DC 20555 i i

Millstone Nuclear Power Station, Unit No. 3 l Chanae to Technical Specification Bases Sections 3/4.5.2 and 3/4.5.3 Emeraency Core Coolina System (ECCS) Subsystems ( TSCR 3-4-99)

Northeast Nuclear Energy Company (NNECO) is providing the NRC Staff with a change to Technical Specification Bases Sections 3/4.5.2 and 3/4.5.3, "ECCS Subsystems" for  !

information only. This change was reviewed and approved by the Millstone Unit No. 3 Plant Operations Review Committee in accordance with the provisions of 10CFR50.59.

Descriotion of Chance l i

The changes to Technical Specification (TS) Bases Sections 3/4.5.2 and 3/4.5.3 )

describes implementation of a design change to Millstone Unit No. 3 which augments the capability of the Emergency Core Cooling System (ECCS) piping to remain full of water. TS surveillance requirement (SR) 4.5.2.b.1 requires verifying every 31 days that the ECCS piping is full of water. On three occasions it was determined that the Recirculation Spray System (RSS) thermal expansion loop failed to meet this TS surveillance requirement. This resulted in a loss of RSS operability while the affected train of the system was vented and filled. In order to preclude voids or pockets of entrained gases in the RSS thermal expansion loops, a continuous vent "ine was installed from the existing local vent valves on the horizontal portions of the RSS thermal expansion loops to the opposite side of the expansion loops, in the vertical riser. The continuous vent lines allow gases that are entrapped in the thermal expansion loops to vent to the upstream side of the loops and eventually out the spray headers inside containment.

Maintaining the piping from the ECCS pumps to the Reactor Coolant System (RCS) full 7 of water ensures that the system will perform within the prescribed limits of its safety analysis and design bases -when required to inject into the RCS. In addition, i

\

9907270150 990716 .

I o PDR ADOCK 05000423 p PDR a

, i

. U.S. Nuclear Regulatory Commission B17818\Page 2 maintaining the piping full of water prevents water hammer, pump cavitation, and pumping of noncondensible gases into the reactor vessel following a safety injection signal.

There are no new regulatory commitments contained within this letter.

If you have any questions, please contact Mr. D. W. Dodson at (860) 447-1791 extension 2346.

Vesy truly yours, NORTHEAST NUCLEAR ENERGY COMPANY R. P. Necci Vice President-Nuclear Oversight and Regulatory Affairs cc: H. J. Miller, Region 1 Administrator J. A. Nakoski, NRC Project Manager, Millstone Unit No. 3 A. C. Cerne, Senior Resident inspector, Millstone Unit No. 3 Director Bureau of Air Management Monitoring and Radiation Division Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127

. _ _ _ _ _ _ _ - _ _ _ _ _ .