ML19256E808
| ML19256E808 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 11/06/1979 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Ippolito T Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7911150275 | |
| Download: ML19256E808 (4) | |
Text
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T E.NN ESS EE V a LLE'/ O -~ '- C l T Y c-:-
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- . r3sz: :w 400 Chestnut Street Tower II November 6, 1979 Director of Nuclear Reactor Regulation Attention:
Mr. Thomas A. Ippolito, Chief Branch No. 3 Division of Operating Reactors U.S. Nuclear Regulatory ommission Washington, DC 20555
Dear Mr. Ippolito:
In the Matter of the
)
Docket Nos. 50-259 Tennessee Valley Authority
)
50-260 50-296 This is in response to your letter dated October 3, 1979, to H. G. Parris concerning low pressure coolant injection (LPCI) power supply modifications for Browns Ferry Nuclear Plant. Enclosed is the additional information and documentation requested by the above letter.
If you have any further questions, please get in touch with us.
Very truly yours, TENNESSEE VALLEY AUTHORI"Y L. M. Mills, Manager Nuclear Regulation and Safety Enclosure 1338 284 A xl 7911150 cD
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ENCL'0SURE RESPONSE TO NRC LETTER DATED OCTOBER 3, 1979, CONCERNING LPCI MG SET MODIFICATIONS AT BROWNS FERRY NUCLEAR PLANT NRC requests the following documentation in writing:
Question 1:
That when Unit No. 3 starts up from the current refueling, the LPCI power supply except for the MG sets will be as shown in Figure 20 entitled, " Modified System Valve Power to Hydraulic Pump With Swing Bus Eliminated" in the document, " Emergency Core Cooling Systems, Low Pressure Coolant Injection, Modifications for Performance Improvement," dated May 1977.
Response
When unit 3 startups up from the current refueling, the LPCI power supply except for the MG sets will be as shown in Figure 20 entitled, " Mad!fied System Valve Power - Unit 3" in the document, " Emergency Core Cooling Injection, Modifications for Performance Improvement," dated October 1977.
Please note that this does not agree with the information requested.
Paragraph 2.E. of facility License No. DPR-68 was amended by subparagraph (6) dated May 13, 1979, to allow modifications as described in the October 1977 document.
Question 2:
The number of days required to install the MG sets once they are received.
Response
We estimate that 50 days will be required to install the MG sets on unit 3.
This includes 28 days to set up the MG sets and 22 days to tie the MG sets to the MOV boards, and to test the MG sets, and transfer control features.
For units 1 and 2, it is estimated that 64 days will be needed.
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Question 3:
That if there is an outage of sufficient duration af ter the MG sets are received, the MG sets will be installed at that time rather than waiting for the fall 1980 refueling outages.
Response
If there is an outage of sufficient duration after the MG sets are received, the MG sets will be installed at that time rather than waiting for the unit 3 fall 1980 refueling outage.
Question 4:
The date of purchase order was issued for the MG sets, a) originally and b) as described in your December 13, 1978, letter.
Response
The original purchase order for the MG sets was issued October 18, 1977.
The purchase contract was amended as described in our December 13, 1978, letter on October 10, 1978.
Question 5:
The dates the modified MG sets for Units 1, 2, and 3 were expected to be delivered onsite and the dates the sets are now scheduled ta be deliverea for each unit.
Discuss how much of the delay is attributable to the strike at the material fabricator's plant and how much is other causes.
Response
The MG sets were originally expected to be delivered onsite as follows:
five MG sets on April 23, 1979, and eight more on July 1, 1979. We are now expecting shipments to begin on December 10, 1979, with complete shipment by December 22, 1979.
The strike at the material fabricator's plant began on June 1, 1979, and ended July 17, 1979.
Conversations witn the manufacturer indicated that because of engineering problems they were behind two months in their schedule before the strike.
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- Ouestion 6:
That design and operation of Units Nos.1 and 3 with the LPCI power supply modification installed, but minus the MG sets, has been reviewed by the Plant Operations Review Committee and the Nuclear Safety Review Board and that acceptable procedures have been prepared (and the plant operating crew trained with the revised procedures) to cover safe operations of Units Nos. 1 and 3 during the temporary period until the MG sets are installed.
Response
The Plant Operations Review Committee has reviewed the design and operation of units 1 and 3 with the LPCI power supply modification installed, but without the MG sets. The Nuclear Safety Review Board has reviewed the unreviewed safety question determination for design and operation of units 1 and 3 with the LPCI power supply modification installed, but without the MG sets.
Procedures will be revised as necessary and training provided to ensure safe operation of units 1 and 3 during the temporary period until the MG sets are installed.
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