ML19321A552

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Preliminary Contentions Alleging Possibility of Steam Generator Tube Rupture During Severe Loca.Contends That Continued Operation W/Significant Tube Degradation Poses Threat to Public.Certificate of Svc Encl
ML19321A552
Person / Time
Site: Point Beach NextEra Energy icon.png
Issue date: 07/15/1980
From: Falk K
WISCONSIN'S ENVIRONMENTAL DECADE
To:
Atomic Safety and Licensing Board Panel
References
ISSUANCES-CO, NUDOCS 8007230607
Download: ML19321A552 (5)


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UNITED STATES OF AMERICA NUCLEAR REGUIATORY COMMISSION -

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BEFORE THE ATOMIC SAFETY AND LICENSING BOARD ( L b I I98Q g 75 In the Matter of ) Ch O

) Docket 50-266 CO D p 7

WISCDEIN ELECTRIC POWER COMPANY )

) (Steam Generator Tube Degradation)

(Point Beach Nuclear Plant Unit 1) )

PETITIONER'S PRELIMINARY CDNTENTIONS

, MADE PRIOR TO DISCOVERY AND CROSS-EXAMINATION Petitioner Wisconsin's Environmental Decade, Inc. (" Decade") , hereby submits, pursuant to the Rules of Practice,10 C.F.R. 2.714 (b) , and the Order Setting First Prehearing Conference, docketed June 25, 1980, the following list of specific contentions sought to be litigated in this proceeding in support of its position that the actions of the Staff have failed in important respects to remedy significant safety concerns:

(1) Steam generator tube rupture during a severe loss-of-coolant-accident

( "LOCA") could occur frequently in pressurized water reactors ("PWR") with severe tube corrosion problems.

(2) The rupture of one to ten such tubes above the lower interface of the steam generator tubesheet during the course of a IOCA would cause secondary-to-primary leakage that could exacerbate steam binding problems ano induce essentially uncoolable conditions.

(3) The progression of steam generator tube degradation at Point Beach Nuclear Plant Unit 1(" Point Beach") in the past twelve months is the nost rapid observed rate of progression of any other PWR in this country.

(4) Continued operation of Point Beach with significant steam generator

. tube degradation poses an undue threat to the public health, safety and interest.

THIS DOCUMENT CONTAINS P00R QUAUTY PAGES 8002230

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(5) It is inadequate basis for continued operation of Point Beach to rely upon Staff findings that steam generator tube degradation above the tubesheet will not rupture during a IOCA, because the observed extent of degradation above the tubesheet has been sufficient to leak under IOCA conditions and because the calculated low volume of the defects above the tubesheet are based upon unsubstantiated asstanptions.

(6) It is an inadequate basis for continued operation of Point Beach to rely upon the staff findings that all presently undiscovered and all future steam generator tube' degradation will be located below the top of the tubesheet for the following reasons:

(a) At least six tubes have been identified with significant degradation at or above the top of the tubesheet cubsequent to August, 1979.

(b) The alleged fact that the eddy current tapes for those six tubes from tests performed prior to August, 1979, contained anomolous signals that continued unchanged through the present does not adequately demonstrate that the defects arose prior to 1979, especially when no analysis was made of the tapes of other tubes to determine how common (and, hence, meaningless) such signals are, when no blind test was done by independent experts and when it is unexplained how such significant degradation could remain essentially dormant so long.

(c) Other identified defects indicated to be below the top of the tubesheet at Point Beach may, in fact, be located at or above the top of the tubesheet, be-cause the size of the eddy current probe prevents resolution of the signal within a band of plus or minus one-half inch.

(d) Even if all corrosive mechanisms at Point Beach are presenr.ly confined below' the top of the tubesheet, thera is a s,ignificant prahrhiEty that at least one to ten tubes have pre -exi.sttuc 6<-rectu <thove the tubeshmt that Nye not yet been identified, because ths ecMy cer, er.t ar4 c.,-arostr. tic testr, for Mtecting

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  • defects are inadequate to produce reliable results with that degree of accuracy.

(e) Even if all corrosive mechanisms at Point Beach are presently confined below the top of the tubesheet and have been identified and plugged, there is an insufficient basis for concluding that the corrosive mechanism will not move' outside of the tubesheet region in the future, because the original shift of observed degradation from akve to below the tubesheet was not predicted, because there is no scientific evidence why the corrosive processes will not reappear above the tubesheet beyond the naked observation that the majority of the u

corrosion presently appears to be below the top of the tubesheet, because the composition of the residential compounds and agents in the steam generators at Point Beach are unique and not understood and because the sludge pile at the bottom of the steam generator and above the tubesheet appears to be active.

(7) It is an inadequate basis for continued operation of Point Beach to rely upon Staff findings that the amount of secondary-to primary leakage during

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a IOCA will be sufficiently low as to not cause steam binding problems, even if all corroded tubes are below the top of the tubesheet, for the following reasons:

} (a) The calculated throttling effect on secondary-to-primary leakage in the tubesheet region does not take into account a tube rupture in the interface region where the existence of corrosion has not been denied and where leakage will be

. significantly greater than deep in the crevice because of the closer proxi.dty to the free standing region of the steam generator.  !

l (b) The collapsetests done to date cannot be used to assess the probability I of a tube collapse during a IOCA within the tubesheet, because the tests were 1

Performed on tubec with significantly less degradation than is, in fact, being i 1

experienced in a relevant nu eber of t@.?, bem ur.e the tests de not adeqactely predict all collapse ned.anist.s ed Weause @c t.srs are perfenef. on a static instead cf dynamic b. asis.

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l (c) The calculated rate of secondary-to-primary leakage necessary to cause

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steam binding problems is too high because of a failure to consider synergistic l

j effects from simultaneous occurrences during a IOCA that will further retard reflood rates.

(d) Significant secondary-to-primary leakage during a IDCA may occur from a previously unconsidered source through any number of the 743 plugged tubes, because such leakage due to defective explosive plugs or wear and tear has been observed under normal operating conditions in at least nine tubes (including one that had been previously weld repaired) and because no tests have been performed to determine plugs' resistance to loosening under postulated accident conditions.

(8) It is an inadequate basis for cantinued operation at Point Beach to rely upon Staff findings that the detection procedures for defects in steam generator tubes will provide adequate assurance that the number of tubes necessary to cause steam binding will not be incipient failures during a LOCA for the following reasons:

(a) The multi-frequency eddy current test and hydrostatic tests do not detect a significant number of tubes with defects, including defects from intergranular attack inside and outside the tubesheet crevice and from caustic stress corrosion less than 40%, as shown by the record of the August, October and December,1979, and March,1980, inspections.

e (b) Frequent in-service inspections do not assure plugging of all incipient i failures, because the observed time from no or slight defect to incipient or i

f complete failure for an affected tube may be less than the time between inspections i

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and because the apparent form of corrosion is stress corrosion and not general Q

f corrosion.

l (c) Reduced permissable primary- to-secondary lede rat.es before mandated

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shutdown for inspecrion and rcpa : cc, f.c,t. sa.:.a cet.cuvn of all 1.wipien: tube failures becuase the observed exocriT:ce balias cuy leak-befw.-bree.k theory and

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because the apparent form of corrosion is stress corrosion and not general corrosion.

DA1ED at Madison, Wisoonsin, this 15th day of July,1980. '

WISCONSIN'S ENVIRONMENTAL DECADE, INC.

By Kathleen M. Falk General Counsel

-302 East Washington Avenue Suite 205 Madison, Wisconsin 53703 (608) 251-7020 CERTIFICATE OF SERVICE I hereby certify that true and correct copies of the foregoing Petitioner's Preliminary July Contentions Made Prior to Discovery and Cross-Examination, dated 15,1980, mails, this 15thhave day beenof July,served 1980:on the following by deposit in the first class Herbert Grossman, Esq. , Dr. Richard F. Cole, Dr. J. Venn Leeds, Atomic Safety and Licensing Board Panal, atomic Safety and Licensing Appeal Panal, Gerald Charnoff,y , Ellyn R. Weiss, Karen Cyr, Esq Richard Hoefling, Esq., and Docketing. .,

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