ML20133G681
| ML20133G681 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 10/08/1985 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 5211-85-2170, NUDOCS 8510160080 | |
| Download: ML20133G681 (2) | |
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GPU Nuclerr Corporation Nuclear
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Middletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Number:
October 8, 1985 5211-85-2170 Office of Nuclear Reactor Regulation Attn: H. R. Denton, Director U.S. Nuclear Regulatory Commission Washington, D. C. 20555
Dear Mr. Denton:
Three Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 10 CFR 50.62 (ATWS Rule) 10 CFR 50.62 concerns requirements for reduction of risk from anticipated transients without scram events for light-water-cooled nuclear power plants.
GPUN is a participating member of Babcock & Wilcox Owners Group (BWOG) and, as such, our response to 10 CFR 50.62 reflects our participation in the development of the Owner's Group position. Pursuant to 10 CFR 50.62(d),
please find attached a schedule for meeting the requirements that apply to a pressurized water reactor,10 CFR 50.62(c) (1) and (c) (2).
Sincerely,
- i. D.
uKill Director, TMI-l HDH:gpa:0379A 2265f/001 Attachment h
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GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation
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ATTACHMENT 4
10 CFR 50.62 (ATWS Rule) i Requirement (d) - Implementation: By 180 days after the issuance of the QA guidance for non-safety related components each licensee shall develop and i
submit to the Director of the Office of Nuclear Reactor Regulation a proposed schedule for meeting the requirements of paragraphs (c) (1) through (c) (5) of i
this section. Each shall include an explanation of the schedule along with a justification if the schedule calls for final implementation later than the second refueling outage after July 26, 1984, or the date of issuance of a i
license authorizing operation above 5 percent of full power. A final schedule shall then be mutually agreed upon by the Commission and Licensee.
4 Discussion - The BWOG, by use of existing and new ATWS transient analyses, j
has developed guidelines relative to implementation of the modifications prescribed by 10 CFR 50.62. Upon evaluation of all applicable ATWS transients j
including the consideration of pertinent event consequences, the limiting transients in every case are the same: Loss of Main Feedwater and Loss of i
Offsite Power. Thus, systens which are designed to prevent or mitigate these specific transients are sufficient to achieve the desired reductions in ATWS i
risk stated by the ATWS rule.
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The schedules provided below are based on the extent of hardware changes, equipment availability and refueling outage work load.
In addition, as a participating member of the BWOG, GPUN's modifications will be based upon the guidelines developed by the Owners Group.
I Requirement (c) (1) - Each pressurized water reactor must have equipment from sensor output to final actuation device, that is diverse from the reactor trip j
system, to automatically initiate the auxiliary (or emergency) feedwater j
system and initiate a turbine trip under conditions indicative of an ATWS.
This equipment must be designed to perform its function in a reliable manner
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and be independent (from sensor output to the final actuation device) from the existing reactor trip system.
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Response - Diverse auto initiation of the emergency feedwater system and turbine trip shall be provided by no later than the Cycle 7 refueling outage.
The initiation signal shall be Loss Of Main Feedwater, i
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l Requirement (c) (2) - Each pressurized water reactor manufactured by l
Combustion Engineering or by Babcock and Wilcox must have a diverse scram system from sensor output to interruption of power to the control rods. This scram system must be designed to perform its function in a reliable manner and i
be independent from the existing reactor trip system (from sensor output to j
interruption of power to the control rods).
j Response - A diverse scram system (DSS) shall be provided by no later than the Cycle 7 refueling outage. The DSS shall trip regulating rod groups 5, 6 and 7 l
upon reciept of high-high RCS pressure.
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