ML20149D893

Followups on Commitment in 870123 Application for Amend to License DPR-50 Re Heat Sink Protection Sys Operational (Hsps) Bypass Capability.Operational Bypass of Hsps Low once-through Steam Generator Not Needed for Future Cycles

ML20149D893
Person / Time
Site:	Three Mile Island
Issue date:	02/03/1988
From:	Hukill H GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
5211-87-2019, TAC-62994, NUDOCS 8802100078
Download: ML20149D893 (2)

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O E Nuclear Eur,i"e'0*m'"*"

Route 441 South IAlddletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84 2385 Writer's Direct Dial Number:

Fdbruary 3,1988 5211-87-2019 (TAC 62994)

U.S. Nuclear Regulatory Commission Attn: Docunent Control Desk Washington, DC 20555

Dear Sir:

Three Mile Island Nuclear Station Unit 1 (TMI-1)

Operating License No. DPR-50 Docket No. 50-289 Heat Sink Protection System (HSPS)-

Operational Bypass Capability The purpose of this letter is to followup on a commitment from our letter dated January 23, 1987 which forwarded Technical Specification Change Request (TSCR) No.166 and inform the NRC that an operational bypass of the HSFS low OTSG 1evel initiation of Emergency Feedwater (EFW) will not be needed for future cycles. GPUN does not feel that it is necessary to reconfigure the HSPS to provide for this bypass capability. Nor do we intend to request an extension of the provisions of Technical Specification (T.S.) 3.5.1.1 which expire subsequent to Cycle 6 operation.

Specifically, T.S. Table 3.5.1.0, footnote (c) permits the operator to disable the HSPS automatic initiation of Emergency Feedwater (EFW) on low OTSG 1evel when indicated reactor power is less than 30% during normal reactor startup or shutdown. T.S. Amendment 124 grants this provision for one cycle of operation to allow sufficient operating experience with the new system and prevent inadvertent EFW initiations in the event that the new system were to demonstrate unacceptable OTSG 1evel oscillations during low power operation.

The design of the HSPS did not require provisions for an operational bypass of the low OTSG 1evel EFW initiation feature because bypass of this feature was not anticipated. Since we did not expect the system to require this bypass capability, GPUN did not discuss the need for this provision with the NRC until our submittal of TSCR 166.

Prior to HSPS startup test and operation, other plants were experiencing inadvertent EFW initiations as a result of level oscillations at low power.

Our system was different from the plants that were experiencing problems; however, we did not wish to experience the inadvertent EFW initiations that might result if level oscillations under actual low power operating conditions were to becote a problem.

GPU Nucim Corooration is a subsidiary of the General Public Utilities Corporation x0*( f 8802100078 000003 PDR ADOCR 05000209 (D l P PDH

o 5211-87-2019  !

Currently as a result of our experience with the HSPS during Cycle 6 '

. operation, including the five startups during Cycle 6, we feel that we have

! gained sufficient confidence in the stability of OTSG level control during low a power operation. Therefore, bypass of HSPS EFW automatic initiation on low OTSG 1evel during low power operation will not be needed for future cycles of

, operation. ,

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Sincerely, i i

s

. . kill Vice President & Director, TMI-1

! HDH/MRi;/spb:0764A i cc: J. Stolz R. Conte f G. Edison W. Russell '

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