ML17055B557
| ML17055B557 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 04/23/1986 |
| From: | Haughey M Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TAC-63425, NUDOCS 8604300356 | |
| Download: ML17055B557 (28) | |
Text
April 23, 1986 Docket No. 50-410 APPLICANT:
Niagara Mohawk Power Corporation (NMPC)
FACILITY:
Nine Mile Point, Unit 2 (NMP-2)
SUBJECT:
SUMMARY
OF APRIL 2, 1986, MEETING TO DISCUSS DOWNCOMERS FOR NMP-2 On April 2, 1986, the NRC staff met with representatives from NMPC and their consultants from Stone and Webster Engineering Corporation (SWEC) to discuss the NMP-2 downcomers.
The meeting was requested by NMPC to discuss the options NMPC is considering to resolve NRC concerns about the structural adequacy of the NMP-2 downcomers.
NMPC stated that they wanted to pursue the least expen-sive of the options that would be acceptable to the NRC.
Options discussed by NMPC include physical modifications, load reduction, and use of future NRC rule changes to reduce the requirements on the downcomers.
Physical modifications discussed were sleeve reinforcements on the upper part of the downcomers, channel reinforcement and tying the downcomers together.
NMPC indicated that a tension support system that ties to the containment walls would not be acceptable because of the large temperature changes causing move-ment of the walls.
The NRC suggested if NMPC reviewed a system of tying the downcomers together, one option might be to make it independent of the contain-ment walls.
In order not to affect the schedule for restart, NMPC indicated a decision on whether physical modifications need to be made to the downcomers during the first refueling outage would need to be made by April 1987.
NMPC stated that, based on their review of Kraftwerk Union (KWU) testing, they believed a 35 percent reduction in the hydrodynamic loads could be justified.
This could result in an overall reduction in loads on the downcomer of 3 to 4 percent.
NMPC further indicated that the methodology used for the Safety Relief Valves (SRVs) was identical to that used on Shoreham.
The NRC staff present at the meeting were not familiar with the details of the review ofSRV loads at Shoreham and therefore could not comment on the acceptability of that methodology.
The approach NMPC was considering to reduce the Condensation Oscillation (CO) loads would include consideration for the compressibility of water.
NRC staff.
stated the NRC review of this consideration could be a lengthy process.
The NMPC proposed schedule for'review of the load reduction proposals includes'n estimated time for NRC review of the new analysis and approaches of 3 months.
The NRC staff stated that the review of the information outlined during the meeting could take considerably longer.
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The NRC further stated that a review of a revised methodology for calculating loads on the downcomers would not be limited to presented data but would include a review of all available data.
NMPC stated they believed the NRC was involved in discussions for rulemaking that would reduce the requirements on the downcomers.
The NRC staff stated, to the best of their knowledge, any near-term rulemaking under discussion would not be applicable to a reduction of the requirements on the downcomers.
Enclosure 1 contains a handout provided by NMPC during their presentation.
Enclosure 2 contains a list of meeting attendees.
/S/
Mary F. Haughev, Project Manager BWR Project Directorate No.
3 Division of BWR Licensing
Enclosures:
As stated cc:
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Mr. B. G. Hooten Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station Unit 2 CC:
Mr. Troy B. Conner, Jr.,
Esq.
Conner 5 Wetterhahn Suite 1050 1747 Pennsylvania
- Avenue, N.W.
Washington, D.C.
20006 Richard Goldsmith Syracuse University College of Law E. I. White Hall Campus
- Syracuse, New York 12223 Ezra I. Bial ik Assistant Attorney General Environmental Protection Bureau New York State Department of Law 2 World Trade Center New York, New York 10047 Resident Inspector Nine Mile Point Nuclear Power Station P. 0.
Box 99
- Lycoming, New York 13093 Mr. John W. Keib, Esq.
Niagara Mohawk Power Corporation 300 Erie Boulevard West
- Syracuse, New York 13202 Mr. James Linville U. S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 Norman Rademacher, Licensing Niagara Mohawk Power Corporation 300 Erie Boulevard West
- Syracuse, New York 13202 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 Mr. Paul D. Eddy New York State Public Service Comml ss 1 on Nine Mile Point Nuclear Station-Unit II Post Office Box 63
- Lycoming, New "Yor k 13093 Don Hill Niagara Mohawk Power Corporation Suite 550 4520 East West HighWay
- Bethesda, Maryland 20814
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B C
0 o
FAULTED CONDITION 0
o SOLUTION LOAD COMBI NATION LOAD GENERATION HARDMARE FIX
0 CO P
I, BACKGROUND I I, PHYSICAL MODIFICATION OPTION o
SLEEVE REINFORCEMENT o
CHANNEL REINFORCEMENT
- III, LOAD GENERATION OPTION o
LOAD COMBINATION o
LOAD REDUCTION o
SRV LOAD REDUCTION o
CO LOAD REDUCTION IV.
CONCLUSION
CHANNEL STIFFENER 2'-0" DIA
OUTER SHELL DOVfNCOMER 2'-0" DIA
SRV LOAD REDUCTION REFINEMENT BASES "USE THE SAME BUBBLE AS BEFORE 5 FT RADIUS BUBBLE AT "THE DONNCOMER TIP (SUSQUEHANNA DAR SEC 4.1.3 7)
USE THE NUREG 0802 FREQUENCY ADJUSTMENT AND PRESSURE MULTIPLIER PROCEDURE (NUREG 0802, SEC. A.1.9.1)
USE THE DATA HASE FOR THE T-QUENCHER AND MARK II GEOMETRY (SUSQUEHANNA DAR SEC. 8.2.1,1.5)
KTG TESTS DATA HAS ACCEPTED FOR USE IN THE DEVELOP-MENT OF DESIGN LOAD SPECIFICATION (NUREG 0802, SEC
~ 2,3.1.1.1)
4 REDUCTION BASES I
I USE PROTOTYPICAL'EST DATA (KTG) TO ELIMINATE UNCER-TAINTY AND REDUCE ENVELOPING I
USE PLANT UNIQUE~MULTIPLIER TO DEFINE MORE APPROPRIATE LOAD THAN GENERIC MULTIPLIERS USED IN THE ALTERNATE NUREG 0802 METHOD I
ANTICIPATED REDUCTION OF PRESSURE
RESPONSE
SPECTRUM AT UOMNCOMER FREQUENCY APPROXIMATELY 35%
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REDUCTION BASES PRESSURE WAVES DO NOT ARRIVE AT THE TARGET AT THE SAME TIME BECAUSE OF THE FINITE WAVE SPEED, ACOUSTIC SPEED IS LOW DURING THE CO PHASE (NEDE 24288-P SEC. 5.4. 1)
I ACTUALLY OBSERVED MULTIVENT CO LOAD IS MUCH LOWER THAN THE SINGLE VENT LOAD (NUREG 0808, SEC. 2.2,1,5,6)
REDUCTION WILL.BE BENCHMARKED WITH JAERI DATA ANTICIPATED REDUCTION IS APPROXIMATELY 55%
CO LOAD REDUCTION REFINEMENT BASES USE THE ACOUSTIC METHOD (IWEGS)
WHICH HAS BEEN ACCEPTED BY NUREG 0808 (NUREG 0808, SEC. 2.2,2,3.3)
USE THE CO SOURCES AS THE MARK II LOAD DEFINITION, SAME AS BEFORE (NEDE 20288-P SEC, 2.1.3 R
NUREG 0808, SEC. 2,2,1,0)
DO NOT USE AMPLITUDE AVERAGING OR RANDOM PHASING, SAME AS BEFORE USE THE CO SOURCE INITIATION TIME AS BEFORE
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LOID REDUCTION STRESS RANGES SRV REDUCTION CO REDUCTION CO AND SRV REDUCTION I
20 24,04 26 68 30 DOWVCORER STRESS KS I
Enclosure 2
APRIL 2, 1986 MEETING ON DOWNCOMERS NAME Mary F. Haughey Jack Kudrick Richard P. Byrnes Mark A. Durka E.
R. Klein T. L.
Wang A. F. Zallnick R. A. Cushman ORGANIZATION NRC NRC/NRR/PSB Stone 5 Webster SWEC NMPC SWF.C NMPC - Licensing NMPC - Licensing
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April 23, 1986 MEETING
SUMMARY
DISTRIBUTION A cket No. 50-410 NRC PDR Local PDR BWD g3 r/f J. Partlow E.
Adensam
- Attorney, OELD E. Jordan B. Grimes ACRS (10)
Proiect Manager M. Haughey E. Hylton C. P.
Tan Y. L. Li F. Eltawila NRC PARTICIPANTS M. Haughey J. Kudrick bcc:
Applicant 8 Service List
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