ML20217P825

Application for Amend to License NPF-3,clarifying Discussion of Margin Between RPS High Pressure Trip Setpoint & Lift Setting for Pressurizer Code Safety Valves

ML20217P825
Person / Time
Site:	Davis Besse
Issue date:	04/24/1998
From:	Jeffery Wood CENTERIOR ENERGY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20217P829	List: ML20217P825 ML20217P835
References
2504, NUDOCS 9805070105
Download: ML20217P825 (2)

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Davis-Besse Nuclear Power Station 5501 North State Route 2 Dak Harbor, Ohio 43449-9760

.lohn K. Wood 419-249-2300 Vice President - Nuclear Far 419-321-8337 License Number NPF-3 Serial Number 2504 i

Docket Number 50-346 April 24, 1998 ,

i United States Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20555-0001

Subject:

Change to Technical Specification Bases 2.2.1, Limiting Safety System Settings - l .

Reactor Protection System Instrumentation Setpoints (LAR 97-0017)

I Ladies and Gentlemen: )

This letter submits an administrative change to the Davis-Besse Nuclear Power Station (DBNPS), Unit Number 1 Technical Specification (TS) Bases 2.2.1, Limiting Safety System Settings - Reactor Protection System (RPS) Instrumentation Setpoints - RC Pressure - Low,  ;

High, and Pressure Temperature. This change is being made to clarify the discussion of the l margin between the RPS high pressure trip setpoint and the lift setting for the Pressurizer Code Safety Valves (PCSV), as described in further detail below. The need for this change was l discussed in a previous letter to the NRC dated November 10,1997 (TE Serial Number 2494).

This administrative change affects only the TS Bases and is not related to any change to the Technical Specifications.

The current TS Bases 2.2.1 includes the following statement:

The RC high pressure trip is backed up by the pressurizer code safety valves for RCS over pressure protection, and is therefore set lower than the set pressure for these valves, s 2525 psig.

This statement, as shown on the attached marked-up TS Bases page,is changed to read:

l The RC high pressure trip is backed up by the pressurizer code safety valves for RCS over pressure protection. The RC high pressure trip is, therefore, set lower than the set

) pressure for these valves,2500 psig (nominal), even when accounting for the RPS RC pressure instrument string uncertainty.

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i . Docket Number 50-346 License Number NPF-3 Serial Number 2504 Page 2 The PCSV set pressure of s 2525 psig in the current TS Bases reflects the " nominal" set pressure of 2500 psig plus 1% for tolerance. However, the TS Bases statement is discussing the fact that the RC high pressure trip setpoint (2355 psig) is lower than the PCSV set pressure. Rehrring to the value of s 2525 psig for the PCSV set pressure is inappropriate in the TS Bases when discus::ing the available margin between the RC high pressure trip setpoint and the PCSV set pressure. Rather, referring to the nominal 2500 psig set pressure is more appropriate in this l context. In addition to referring to the nominal PCSV set pressure, the Bases change is also I

proposed to include a reference to RPS RC pressure instrument string uncertainty. These are administrative changes and have no effect on plant safety.

In addition to the above-referenced changes, a correction is also included to the Amendment i references at the bottom of the same Bases page. The reference to Amendment No. 23 is l changed to Amendment No. 33. This is an administrative change and has no effect on plant safety.

Toledo Edison requests that this TS Bases change be issued by October 30,1998.

Should you have any questions or require additional information, please contact Mr. James L. Freels, Manager - Regulatory Affairs, at (419) 321-8466.

Ve ruly yours,

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MKL/laj Attachment ,

cc: A. B. Beach, Regional Administrator, NRC Region III S. J. Campbell, DB-1 NRC Senior Resident Inspector A. G. Hansen, DB-1 NRC/NRR Project Manager J. R. Williams, Chief of Staff, Ohio Emergency Management Agency, State of Ohio (NRC Liaison)

Utility Radiological Safety Board i l

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