ML20090L820

Forwards Nutech Rept NSP-01-168, Monticello Nuclear Generating Plant Suppl to Short-Term Program,Plant-Unique Torus Support & Attached Piping Analysis

ML20090L820
Person / Time
Site:	Monticello
Issue date:	10/12/1976
From:	Mayer L NORTHERN STATES POWER CO.
To:	Stello V Office of Nuclear Reactor Regulation
Shared Package
ML20090L823	List: ML20090L820 ML20090L825
References
NUDOCS 9102130404
Download: ML20090L820 (5)

Text

- - - - - - -

t J .

NSF NORTHERH ETATES POWER COMPANY

-,~~....m..~,~~..... ...o,

. .: i October 12, h ', .

m CO?Yp}%N p -

( v n# .

3

• Mr Victor Stello, Director \' o Division of Operating Reactors ( g@ , , , ', a D Cg /

U S Nuclear Regulatory Commission *y ,cjp Washington, DC 20555 w g ,

Dear Mr Stello:

N t o' e

MONTICELID NUCIIAR GENERATING PIANT Docket No. 50-263 License No. DPR-22

References:

(a) NUTECH Ren +t NSP-01-140, "Monticello Nuclear Generating Plant Short Term Program Plant Unique Torus Support and Attached Piping Analysis", August, 1976 (b) GE Report No. NEDC-20989-P, " Mark I Containment Evaluation Short Term Program, Addendum 2, Loads and Their Application for Torus Support System Evaluation", June, 1976 (c) GE Report No. NEDC-20989-P, Addendum 3. " Mark I

. Containment Evaluation Short Term Program Final Report", August, 1976 Mark I Containment Information Attached are forty copies of NUTICH Report NSP-01-168 titled "Monticello Nuclear Generating Plant Supplement to Siort Term Program Plant Unique Terus Support and Attached Piping Analysis". 'lhis report presents an evaluation of the effects of maximum torus water level on STP loads, as reported in reference (a); and an evaluation of the effects of input parameter errors on the results reported in reference (a). Appendix A of the attached rcport contains revised tables to references (b) and (c), which show the corrected input data and analytical re-suits.

A change to reference (a) is noted in t pendix B oi' the attached report.

Reference 10 of reference (a) should..be changed to read as shown above in reference (c). < s c[ Sk... e i ocuU5 p

a"mu Bab e

Sik8

%g -

icaea

'. Noh . HERN QTATED POWER CCerdPANY Mr Victor Stello Pabe 2 October 12, 1976 Responses to the NRC staf f questions of January,1976, on NEDC-20989, were sub-mitted by a letter dated September 9,1976 f rom L J Sobon to V Stello. We have found the information reported in the September 9 letter to be applicable to Monticello.

Several of the January, 1976 staff questions concerning plant t nique information were not addressed in the September 91ctter. Responses to the plant unique questicus are as follows:

St ructural Engeerinn Branch

4. Short term repairs were reported in a letter to Mr Stello dated May 10, 1976.

5. As a result of the short term repairs reported on May 10, 1976, there are no critical otructural elements on the Monticello containment that are near yield due to pool swell loads. A schedu~e of inspectionc of pin  !!$

joints and anchorage will be instituted to ensure their continued integrity.

Mechanical fasteners on the catwalks, vent header support pin joints and safety re'ief valve discharge piping supports inside the torus will be visually inspected each time the torus is ' rained. Ir.spectiors of the pin joints and anchorage on the torus support system and ECCS header will be visually inspected during the course of normal plant inspections. Pre-vious detailed inspections of these systems have not uncovered any deficiencies and, therefore, are supportive of the inspection intervals stated abover

7. Answer contained in reference (a).

8. Net applicable to Monticello.

10. Answer contained in reference (a).

30. Same as answer to 5.

Containment Systems Branch

8. The instrument airlines inside the Monticello torus are those going to the vacuum breakers. There is only one containment penetration for the air supply, which has a normally shut isolation valve outside of con-tainment. The air supply is used only for periodic surveillance testing of the vacuum breakers and is not required for them to perform their accident function. A screening analysis of this arrangement was pre-

, ated in the STP Report , Volume 111. Section 4.3.8.

9. Not applicable to Monticello.

19. Answer contained in reference (a) .

20. Answer contained in reference (a).

O e .o NON e HERN OTATED POWER COMPANY Mr Victor Stello Page 3 October 12, 1976 Mechanical Engineering firanch

3. Answer contained in reference (a).

4 Answer contained in reference (a).

7. Answer contained in a letter to Mr D L Ziemann dated December 16, 1975.

Responses to the NRC staff questions of August, 1976 related to the Long Tenn Prc,3 ram content were submitted by a letter frcun Mr L J Sobon to V Stello dated August 25, 1976. We have found the infonnation in Mr Sobon's letter to be applicable to Monticello.

Yours very truly, p('O.$tn L 0 Mayer, PE Manager of Nuclear Support Services LOM/LLT/ak cc: J G Keppler C Charnoff MPCA Attn: J W Pennan Attachment 1

i o

l

O r s UNITED STATES NUCIIAR REGULATORY Colt (ISSION NORDIERN STATES POWER COMPANY HONTICE1,1D NUC!IAR GENERATING PLANT Docket No. 50 263 License No. DPR-22 11' ITER DATED October 12, 1976 RESPONDING TO NRC REQUESTS FOR INFORMATION ON CONTAINMENT DESIGN Northern States Pwer Cmpany, a Minnesota corporation, by this letter dated October 12, 1976 hereby sebmits inf ormation in response to NRC request s f or inf ormation concerning the Mark 1 Cont aitunent.

This request contains no restricted or other defense information.

NORDIERN STATES POWER COMPANY By C E

! L TWachter Vice President, Pwer Production i & System Operation On this 12th day of October 1976, before me a notary public in and f:r

said County, personally appeared L J Wachter, Vice President, Pwer Productf on

and System Operation, and being first duly sworn acknwledged that he is authorized to execute this document on behalf of Northern States Pwer i Ccanpany, that he knws the contents thereof and that to the best of his knwledge, information and belief, the statements made in it are true and that it is not interposed for delay.

i o

/

A&4O

1. ^4 DENISE E. BRANAtt j N01".RY PU8i'C - KM($31 A HENN; PIN COUNTY k D, Wy Commission ispues 0110. luti ;

.,u e .mn , me u nwoon n a -