ML20215A307
| ML20215A307 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/05/1986 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| 5211-86-2200, NUDOCS 8612110242 | |
| Download: ML20215A307 (3) | |
Text
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GPU Nuclear Corporation Nuclear
- ,omgr8o Middletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Number:
December 5,1986 5211-86-2200 Office of Nuclear Reactor Regulation Attn:
J. F. Stolz, Director PWR Projects Directorate No. 6 US Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Stolz:
Three Mile Island Nuclear Station Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 THI-l FHB ESF Ventilation System Modifications provides GPUN's responses to questions raised during conference calls with the NRC on October 29, 1986, November 3,1986 and November 10, 1986.
Sincerely, ukill Vice President & Director, THI-1 HDH/JA:nk:1471g cc:
J. Thoma R. Conto Attachment 8612110242 861205 DR ADOCK 0500 9
0 I
i GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation
RESPONSES TO NRC QUESTIONS ON TMI-1 FHB ESF VENTILATION SYSTEM Question 1.
Who performed the seismic evaluation?
Response
The seismic evaluation was performed by a structural engineer employed by Burns and Roe.
Question 2.
What is the additional load associated with the concrete foundations and pads?
Response
The additional load associated with the concrete foundations and pads is 123 KIP.
Question 3.
What type of seismic evaluation was performed? That is, provide more specific information concerning the statement in your letter on this subject dated October 1,1986, that the additional load has been evaluated and is negligible.
Response
The mathematical model used by Gilbert Commonwealth Associates for the seismic analysis of the fuel handling and auxiliary building, is a vertical cantilever beam with loads concentrated at five (5) nodes.
This model was evaluated as is, being neither reconfigured nor re-analyzed to reflect the effect of the loads associated with the ESF ventilation system. These loads are:
ESF Enclosure 45 KIP Conduits and Supports 3 KIP HVAC Ducts and Supports 11 KIP Fans and Dampers 34 KIP Concrete Foundations and Pads 123 KIP 216 KIP TOTAL The additional load specified above is located at the second node above ground level on the model.
This node had a load of 43,871.5 KIP associated with it in the Gilbert analysis.
The new load (216 KIP) represents an increase of less than one-half of one percent (0.5%) of the model load (43,871.5 K!P). Furthermore, the sum of the loads located at the second node and the three (3) nodes above it in the model is 99,738.5 KIP. The load associated with the ESF ventilation system represents an increase of less than one-quarter of one percent (0.25%) of the model loads. The evaluation thus concluded that the global seismic integrity and response are unaffected by this modification. Also, the evaluation concluded that the local response is unaffected. This conclusion is based on the fact that the auxiliary building concrete slab roof is over four (4) feet thick in the area of the modification, is reinforced with steel bar and is tied into the building structure.
The roof was designed to withstand the impact of a jetliner at a load of 17,000 KIP.
Question 4.
How do you plan to insure that future modifications to the fuel handling building or the ESF ventilation system will not invalidate the ESF ventilation system one-time pre-operational negative pressure test?
Response
Existing design review procedures require reviewing the FSAR when completing safety evaluations for modifications.
This ensures that FSAR requirements are not altered by the modifications or if they are altered, that these requirements are not invalidated. The ESF system and building configuration used during the one time preoperational negative pressure test will be reflected in the FSAR.
Question 5.
What procedural control ensures that the FHB roll-up door will be maintained closed during fuel handling operations?
Response
The procedure RP 1501-1, " Fuel Handling Limits and Precautions", contains the requirement to ensure that the FHB roll-up door is closed during fuel handling.
Question 6.
What procedural control exists which ensures timely notification of the TMI-2 Control Room in the event of a TMI-1 fuel handling accident?
Response
Alarm response procedures for RM-A4 and RM-G9 are being modified to include notification of TMI-2 in the event of a TMI-1 fuel handling event.
Question 7.
What procedural control exists which ensures that TMI-2, af ter notification from TMI-1 as to the existence of a fuel handling accident, will isolate its FHB ventilation system?
Response
The procedures 4210-0PS-3852.01, " Instrument Air System" and 4210-0PS-3830.01, " Fuel Handling Building Heating and Ventilation", are being modified to include an action to isolate the TMI-2 FHB ventilation upon notification of a TMI-1 fuel handling accident. t
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