ML20150E322
| ML20150E322 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/25/1988 |
| From: | Standerfer F GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8803310006 | |
| Download: ML20150E322 (2) | |
Text
.
t GPU Nuclear Corporation MNuclear
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Middletown Pennsylvania 17057 0191 717 944-7621 TELEX 84 2386 Water's Direct Dial Number:
(717) 948-8461 March 25, 1988 4410-88-L-0050/0370P US Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Dear Sirs:
Three Mlle Island Nuclear Station, Unit 2 (TMI-2)
Operating License No. DPR-73 Docket No. 50-320 Use of Core Bore Machine for Dismantling Lower Core o, port Assembly For purposes of information, GPU Nut r is providing notification of our plans to use the core bore machine at selected ligament intersections to section the Lower Grid Rib Section (LGRS) portion of the Lower Core Support Assembly (LCSA). This activity will enable the TMI-2 defueling evolution to continue in an expeditious manner.
Based on the below analysis, GPU Nuclear has determined that this activity does not constitute an unreviewed safety question pursuant to 10 CFR 50.59.
GPU Nuclear letter 4410-87-L-0189, dated December 28, 1987, requested use of the core bore machine for dismantling and defueling the LCSA.
This request was approved via NRC letter NRC/TMI-88-003 dated January 8,1988. The referenced GPU Nuclear letter stated that the core tore machine would be used to bore through all 52 incore spiders and then complet ~.y bore (i.e., sever from the LCSA) up to 15 outer periphery incore guide tubes. Additionally, the referenced GPU Nuclear letter stated that the support posts would be bored through to the lower grid forging with 16 outer periphery support posts being completely bored through the lower grid forging.
Following the activities described above, GPU Nuclear had planned to use the Automatic Cutting Equipment System ( ACES) for cutting the LCSA as addressed in GPU Nuclear letter 4410-88-L-0005, dated January 18, 1988. Use of the core bore machine to date has been generally successful. Thus, in addition to the ongoing activities described in the above referenced GPU Nuclear letter, GPU Nuclear plans to use the core bore machine to section the LGRS at additional 8803310006 880325 i \\
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DCD GPU Nuclear Corporation is a subsidiary of the General Pubhc Utihties Corporation i
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Document Control Desk March 2% 1988 4410-88-L-0050 selected ligament intersectior.s. The planned severa7ces are similar to those currently being performed at the support posts except that support posts do not exist below the intersection locations where the additional severances will be performed. The severed section(s) of the LGPS have the potential to fall approximately 5-1/2 inches to the flow distributor plate. This planned activity will not impair the capability of the flow distributor to absorb the impact energy of such a load drop. The LGRS is below the top of the incore guide tubes; thus, no axial loads on the guide tubes can result.
Consequently, no axial loads can be transmitted to the incore nozzles in the lower head region. Potential lateral loads on the incore guide tubes will be absorbed by the incore guide tube support plate and the elliptical flow distributor. Therefore, the planned activity will not affect the integrity of the reactor vessel.
The operational limitations established for the core bore machine operation, as stited in the referenced GPU Nuclear and NRC letters, will continue to apply during the described activity.
Based on the above, GPU Nuclear has concluded that this activity is bounded by the evaluations in the referenced GPU Nuclear and NRC letters.
This operation does not increase the consequences or the prnbability of an accident previously evaluated, create the possibility for an accident of a dif ferent type then those previcusly evaluated, or reduce the margin of safety as defined in the Technical Specifications. In addition, this operation does not require a change to the Technical Specifications. GPU Nuclear has concluded that the core bore mac,ine can be used for the operation described without Csenting an undu? risk to the health and safety of the public and this activity does not constitute an unreviewed safety question pursuant to 10 CFR 50.59.
l Sincerely, F. R. Standerf r Director, TMI-2 l
l RDW/ emf cc: Senior Resident Inspector, TMI - R. J. Conte Regional Administrator, Region 1 - W. T. Russell Director, Plant Directorate IV - J. F. Stolz Systems Engineer, TMI Site - L. H. Thonus l
l
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