ML20009A583

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Informs That Util Will Provide NRC W/Description of C-E Heated Junction Thermocouple Sys by 810901 Upon Demonstration of Feasibility.Submittal Will Include Info Re NUREG-0737,Item II.F.2
ML20009A583
Person / Time
Site: Prairie Island  Xcel Energy icon.png
Issue date: 07/06/1981
From: Mayer L
NORTHERN STATES POWER CO.
To:
Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM TAC-12428, TAC-12429, NUDOCS 8107130345
Download: ML20009A583 (1)


Text

eff Northem States Power Company 414 NicoHet Mall

%nneapolis. Minnesota 55401 Teiephone (612) 330-5500 July 6, 1981

, (D ts Director of Nuclear Reactor Regulation .

S U S Nuclear Reg'ilatory Cocnission Washington, DC 20555 g

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{J ugi PRAIRIE ISIAND NUCLEAR GENERATING PIANT u A Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 I

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Instrumentation for Detection of Inadequate Core Cool Ref: (a) Letter from L 0 Mayer, NSP, to Director of NRR, USNRC, dated November 20, 1981,

" Request for Relief from Implementation Schedule for NUREG-0737, Item II.F.2, Instrumentation for Detection of Inadequate Core Cooling" (b) Letter from L 0 Mayer, NSP, to Director of NRR, USNRC, dated Dece:tber 30, 1981,

" Post TMI Requirements - NUREG-0737" References (a) and (b) responded to the licensee submittal requirements of NUREG-0737, Item II.F.2. Northern States Power Company described planned instrumentation fer the detection of inadequate core cooling consisting of subcooling monitors and upgraded core exit themocouples. A delay in the implementation schedule was requested in the case of vessel level instrumentation because, in our view, no system was avail-able which could satisfy all of the requirements of the NRC Staff by January 1, 1982.

We believe the difficulties in meeting the NRC Staff requirements for vest.el level instrumentation noted in referr. ice (a) are still valid. However, we have continued to follow the development of vessel level instrumentation and in late 1980 it became

lear to us that a level measurement system involving the heat transfer characteristics of the sur-ce ding medium offered important advantages over other systems. An Ad Hoc Ccamittee of Westinghouse plant owners, including Northern States Power Company, was fomed to closely follow the development of the Cembustion Engineering (CE) Heated lunction Themoccuple System (HJTCS) and implement it in Westinghorse plants.

Northern States Power Company will, by September 1,1981, provide the NRC Staff with a description of the CE HJTCS sich is currently planned for use at Prairie

! Island upon demonstration of its feasibility. This submittal will include as much of the information requested in NUREG-0737 as practicable.

j L 0 Mayer, P Manager of Nuclear Support Services LOM/DMBi/dm cc J G Keppler NRC Resident Inspector l

G Charnoff 8107130345 810706 b p DR ADOCK 03000282 cg

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