ML20138A650

Motion to Broaden Scope of Hearing to Include Gpu Tech Spec Change Request (Tscr) 153,revising Steam Generator Tube Plugging Criteria.Safety Concern Re Compliance of Tscrs 148 & 153 W/Reg Guide 1.121 Exists.Certificate of Svc Encl

ML20138A650
Person / Time
Site:	Three Mile Island
Issue date:	03/10/1986
From:	Doroshow J THREE MILE ISLAND ALERT
To:	Atomic Safety and Licensing Board Panel
Shared Package
ML20138A268	List: ML20138A263 ML20138A269 ML20138A650
References
RTR-REGGD-01.121, RTR-REGGD-1.121 OLA, NUDOCS 8603140372
Download: ML20138A650 (9)

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UNITED STATES OF AMERICA  !

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NUCLEAR REGULATORY COMMISSION f j.y)

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Before the Atomic Safety and Licensing -Board 6]$ ~

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'e i ?as In the Matter of ) 6 'M-ldM'FQi A METROPOLITAN EDISON COMPANY

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) Docket 4 /M3OGg g pf)B

) (Steam or (Three Mile Island Nuclear ) Plugging Criteria)

Station, Unit 1) )

TMIA'S MOTION TO BROADEN IIEARING SCOPE INTRODUCTION On February 21, 1986, the NRC Staff notified the Licensing Board of its position regarding whether the hearing scope in this proceeding should be broadened to include litigation of Licensee's Technical Specification Change Request (TSCR) No. 153, which would allow TMI-l's operation with steam generator tube defects up to 50%

throughwall with a maximum length of .55 inches. TMIA has requested a hearing on this license amendment request, which it has attached hereto as Exhibit 1.

The Staff and the Licensee argue that TSCR 153 is so different from the subject of this hearing, that it should be considered within the context of an entirely separate proceeing. The Staff bases this conclusion on a determination that TSCR 153 satisfies Reg. Guide 1.121, whereas TSCR 148 does not.

Ilowever, transcripts of discussions between the NRC Staf f and GPU, as well as Staf f concerns apparently expressed to GPU in a July 16, 1985, telephone conversation, (see TSCR 148 at 8-12), show clearly that the broad safety questions rhised by any change the plugging criteria at this time have little to do with the vague provisions of Reg. Guide 1.121.

B603140372 860310 PDR ADOCK 05000289 o PDR

7 Rather, these questions concern the nature of new indications discovered in a 1984 steam generator inspection, and the capability of eddy current testing to accurately asses the size and configuration, indeed the very existence, of tube defects, whether 50% or up to 70% throughwall.

Because the unresolved issues surrounding both requests are virtually identical, TMIA hereby moves to broaden the scope to this proceeding to include TSCR 153. Requiring two separate hearings in this case would be an extraordinary waste of agency resources. In addition, it would place an unreasonable and completely unjustified financial burden on the sole intervenor, TMIA.

DISCUSSION According to GPU, there are two reasons for revising the plugging criteria at this time. One reason is to more accurately reflect the condition of the TMI-1 steam generator. The other is to reflect the capabilities of eddy current testing at TMI-1. TSCR 148 at Section II; TSCR 153 at Section II.1/

To support both requests, the Licensee relies upon the same technical reports to demonstrate both that the amendments comply with the requirements of the GDC 14, 15 and 312/, and Reg. Guide 1.121, and generally would not endanger the public. The company's

1. In TSCR 153, the company provides an additional reason --

the reduction in occupational radiation doses. This reason also was presented to the Staf f during their 1985 meeting on TSCR 148, and provoked a skeptical reaction from the Staff. See NRC Staf f/GPU Meeting (Feb. 19,198 5 ), Tr. a t 7 7.

2. TMIA's proposed Contention 4 addresses deficiencies in the (Footnote continued on next page) l i

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safetyievaluations for both TSCR 148 and TSCR 153 are is based on j the assumption that eddy current technology " indicates that

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' imperfections greater than 40% throughwall are acceptable." i

, e l For both' requests, the analytical basis for the Licensee's >

! . fatigue analysis is contained in GPU's Technical Document Report ,

t i l ("TDR") 008; the ASME Section III fatigue evaluation,Section XI [

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L Linear Elastic Fracture Mechanics results, and the Main Steam l i l Line Break solid mechanics analysis, with a 10% margin on nominal l - l throughwall.' TSCR 148 at 4; TSCR 153 at Sec. III. The company uses identical TDR's to support its characterization of current j defects, and to demonstrate the accuracy of eddy current  :

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[ techniques. See TDR-638, TDR-652, TDR-686, and TDR-642. i i

TDR-690 evaluates the criteria proposed by TSCR 148 against l i

Reg. Guide 1.121. TDR-758 evaluates the criteria proposed by TSCR l

'153 against Reg. Guide 1.121. Both argue that an additional [;

thickness degredation allowance for corrosion and wear is not necessary, claiming "the mechanism for continued chemical attack i

from the inner surf ace has been arrested . . and the TMI-l steam -

I (Footnote continued from previous page) '

Licensee's demonstration of GDC 31 compliance, applicable to both TSCR 148 and TSCR 153. Specifically, GPU has demonstrated i compliance with GDC 31 by using ASME Section XI App. A methodology,  !

which directs.that' variables affecting the data should be i cor:sidered, including environmental effects. GPU has refused to i take environmental ef fects into account for both license amendment l

, requests.

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! In addition, TMIA's proposed Contention 3 addresses the  !

l failure to demonstrate compliance with GDC .32 and true for both  !

requests. This issue concerns the form of degradation and the l

! nature of tube defects. See- NRC Staf f/GPU Meeting (Feb.19, 1985), r l Tr. 'a t 8-9, 3 9 ( Liaw) . '

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generators do not have a history of either tube f ailure by wear on the outer surf ace . . . TSCR 14 8 at 5; TSCR 153 at Section II; TDR-7 5 8 a t 2.

According to the Staff, any new plugging criteria at TMI-1 must be judged against both eddy current testing uncertainties, and knowledge of the f orm and rate of the new tube degradation. NRC Staff /GPU Meeting (Feb. 19, 1985), Tr. at 19, 23. Both criteria must be evaluated in light of the very same technical analyses, particularly on the issue of whether the analyses are reliable enough to support a plugging criteria change without verification through metallurgical examinations of newly pulled TMI-1 tubes.3/

Indeed, the key questions raised by the Staff in 1985 concerning TSCR 148, and in 1986 concerning TSCR 153, such as whether the new indications can be detected, whether degradation is proceeding, and whether grain drop out has stopped or is likely to continue, have not been answered by Licensee's technical analyses.

3. Since tubes were last pulled f rom TMI-1 in 1982, the steam generators have been subjected to thermal / hydraulic loading associated with hot functional testing and plant operation, and have been subjected to new flow patterns from the last round of extensive plugging, which may have resulted in tube wear. See TDR-690.

The Staf f is requiring destructive testing on actual steam generator tubes before evaluating TSCR 148. There are two purposes for this. One is "to get come confirmation on the eddy current technique versus actual metallurgical examination." NRC Staff /GPU Meeting (Jan. 2 9,1986), Tr. a t 27 (Crutchfield). The second is to verify that no additional degradation mechanisms are going on. NRC Staff /GPU Meeting (Jan. 29, 1986), Tr. at 23 (Cheng). Until such actual testing is done, the Staf f considers the license amendment deficient, "to be missing a piece, a substantial piece in the  !

s ta f f 's eye s." NRC Staf f /GPU Meeting (Jan. 2 9,19 8 6 ), Tr. a t 3 3 )

(Crutchfield). l l

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NRC Staf f/GPU Meeting (Jan. 2 9,198 6 ) , Tr. a t 14.

Both criteria revisions rely on unique eddy current testing methods for which there it little or no industry experience to verify their accuracy. TMI-1 steam generators must undergo a dual examination method. The differential technique is used first. If this technique fails to reveal a " relevant" indication, the tube is deemed " acceptable." If a " relevant" indication appears, a more sensitive 8x1 absolute probe is done to confirm the indication, and to determine crack length. TDR-652 at 7.

A defect's throughwall penetration is measured by an eddy current signal's phase angle, which is then compared to a conversion curve to determine the percent throughwall. TSCR 148 at

7. Ilowever, unlike other plants, THI-l's defects are on the inner tube diameter ("ID"). Traditional curves were designed for the 1

l more common outer diameter ("OD") defects, which GPU claims I

l "overcalls" small volume ID defects. Ibid. Therefore, GPU l

designed a new, less conservative curve by extrapolating f rom the OD curve and f actoring in " supplemental data." TDR-642.

The accuracy of Licensee's system has been " correlated" only by using old IGSAC samples. Ibid. Its accuracy has not been l confirmed by metallurgical examination on newly pulled TMI-l tubes, which contain unverified f orms of degradation admittedly dif ficult I

to detect with eddy current methods. See TDR-686; NRC Staff /GPU 1

Meeting (Jan. 2 9, 19 86 ) , Tr. a t 41.

Moreover, both requests introduce an entirely new consideration in plugging analysis. Under the current license, all cracks greater than 40% throughwall must be plugged irrespective of circumferential length. Under both proposed revisions, plugging

criteria would define degraded tubes in terms of circumferential length in addition to throughwall penetration. Therefore, there is heavy reliance on Licensee's ability to accurately measure crack length. See NRC Staf f /GPU Meeting (Feb.19, 1985), Tr. at 40 (Liaw).

Crack length measurements are not precise, but are determined by the number of coils measured. For purposes of TSCR 153, indications revealing more than three coils must be plugged.

NRC Staff /GPU Meeting (Jan. 29, 1986), Tr. at 12. Ilowever, coil measurements are not always accurate, and can underestimate crack l size. See TDR-686 at 13; TDR-652 at 11. Staf f members have expressed concern about eddy current's ability to detect circumferential length to the degree of accuracy required. See e.g. NRC Staf f /GPU Meeting (Feb. 19,19 8 5), Tr. a t 4 7 (Liaw).

In addition, evaluation of plugging criteria based on crack length under either criteria revision must resolve the yet unsolved structural problems of OD and ID surf ace flaws at the same elevation. See TDR-758 at 9.

IGA is particularly difficult to detect using eddy current methods. NRC Staff /GPU Meeting (Jan. 29, 1986), Tr. at 41.

According to TDR-690, the inability to call IGA defects impacts the statistics associated with eddy current accuracy. TDR-690 at 9.

Unless there is grain drop out, IGA is not be detectable.

Grain drop out, however, can also mask otherwise detectable cracks. Past TMI-1 inspections showed that in some cases there were cracks originating at the base of IGA or intergranular pits propogating further through the tube thickness than through the IGA, masking the crack. TSCR 148 at 11-12.

Currently, there is no way to tell without metallurgical examination, whether grain drop out will continue. NRC Staff /GPU Meeting (Jan. 29,1986), Tr. at 21 (Crutchfield). Nor is there any way to determine pit density, whether pits can be expected to stay separate, and whether load-carrying capability could be af fected.

NRC Staff /GPU Meeting (Feb. 19, 1985), Tr. at 31 (Johnston). These issues pertain to both proposals, and must be resolved before there can be assurance that either proposal can be implemented safely.

In sum, the questions which must be litigated and answered are fundamental to both TSCR 148 and TSCR 153. They extend far beyond i whether Reg. Guide 1.121 is satisfied. The questions really concern whether any plugging revision which would decrease the safety margin, is appropriate at this time, when the company has the least knowledge about the true condition of the steam generator since the 1981 corrosive attack. Clearly, these amendments should be considered together.

Respectfully submitted, TilREE MILE ISLAND ALERT By: -

Art / N oanne Doroshow l

Dated: March 10, 1986 p g-y \

ffA'q I l $

b l- UNITED STATES OF AMERICA -

o NUCLEAR REGULATORY COMMISSION h 1, O'* y I

%h $g In the Matter of ) g i

( METROPOLITAN EDISION COMPANY ) Docket No. 50-289 4M l t ) (Steam Generator  !

l (Three Mile Island Nuclear ) Plugging Criteria)

[ Station, Unit 1) )

CERTIFICATE OF SERVICE I I hereby certify that one copy of TMIA'S SUPPLEMENT TO r PETI" ION FOR LEAVE TO INTERVENE, THREE MILE ISLAND ALERT'S FORMAL ,

DEMN) FOR ADJUDICATORY llEARING ON AMENDMENT TO TMI-l OPERATING LICENSE TO CHANGE TUBE PLUGGING CRITERIA, AND TMIA'S MOTION TO I BROADEN ~ HEARING SCOPE, was served this loth day of March,1986, by hand-delivery to all parties on the service , list below.

l N -

anne Doroshow  ;

i Sheldon J. Wolfe, Chairman Administrative Judge i

( -U.S. Nuclear Regulatory Commission I Washington, D.C. 20555 j Frederick J. Shon Oscar H. Paris i i

Administrative Judge Administrative Judge  !

U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission  !

Washington, D.C. 20555 Washington, D.C. 20555 i

t Docketing and Service Section Bruce W. Churhill, Esq. i U.S. Nuclear Regulatory Commission Shaw, Pittman, Potts &

l Washington, D.C. 20555 Trowbridge  !

l 1800 M St. N.W.  ;

} Washington, D.C. 20036 l t

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Mary Wagner i Office of the Executive Legal Director f U.S Nuclear Regulatory Commission

! Washington, D.C. 20555 [

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Chairman Nunzio Palladino  ;

U.S. Nuclear Regulatory Commission  :

Washington, D.C. 20555 l

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Commission'Asselstine U.S. Nuclear Regulatory Commission Washington _, D.C. 20555  !

Commissioner Roberts '

U.S. Nuclear Regulatory Commission

j. Washington, D.C. 20555 Commissioner Bernthal

.U.S. Nuclear Regulatory Commission l Washington,.D.C. 20555 '

Commissioner Zech U.S. Nuclear Regulatory Commission .

t Washington, D.C. 20555 i

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