ML20153A897

Outlines Recommendations & Proposed Course of Action Re Results of Safe End Inspec & Metallographics Exams Relevant to Insvc Inspec, Mod & Design Qual of 4 Types of Safe Ends for Recirculation Nozzles

ML20153A897
Person / Time
Site:	Duane Arnold
Issue date:	09/29/1978
From:	Jordan E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:	Grimes B, Jordan E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE), Office of Nuclear Reactor Regulation
Shared Package
ML20064F298	List: ML20153A897
References
NUDOCS 7811280493
Download: ML20153A897 (4)

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Date:

SEP 2 91978 SeH al ~ No. :

IE:ROI: 78-10 TRANSFER OF LEAD RESPONSIBILITY

.T,0,:

B. K. Grimes, Assistant Director for Engineering and Projects, NRR 0

SUBJECT:

SAFE ENDS FOR RECIRCULATION N0ZILES _

RESPONSIBLE ASSISTANT DIRECTOR:

E. L. Jordan DESCRIPTION OF ITEM RE00 IRING' RESOLUTION:

With regard to operating BWR's,1has identified five types ofs afe ends which have been used to connect recircuTation inlet 11nes (to fEactor vessel nozzles.Four cf these types include thermal sleeves which are welded to the safe ends. The material is inconel for Type 1 safe ends and stainless steel for Types 2, 3, and 4 saf~e ends.

The design of Tvoes 1 and 3 safe ends includes a crevice at the thermal sleeve to safe end joint. The design of Types 2 and 4 safe ends preciuoes the crevice at the joint,~ but does include stagnant water.*

_nunne Arnold has Type 1 safe ends.

All of them have cracked and one crack extendLthru_ the_ safe _end wall. The safe ends have been Mand are being rsplaced witn otners of modified design.

Metallographic examination of the cracked safe ends is in progress' M-to detemine the cause of cracking. This work is being performed by independent laboratories under contract to the licensee and IE.

6 O, Two other units, Brunswick 1 and 2, have Type 1 safe ends.

Based on preliminary metalTogr5phic resiiTts from Duane Arnold, an imediate action letter has been sent to the licensee for Brunswick specifyina

.y.olmet ri c namination of the safe ends in the vicinity of the.

N" thermal sleeve to safe end wetos.

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Preliminary metallographic results obtained for Duan Arnold safe ends indicate that the cause of cracking may be str ss corrosion at the tip of the crevice.

Nevertheless, vibration induced fatione originating from the jet pump riser may be 'a contributing factor.

Because of the presence of crevices and stagnant water in the Type 3 design, NRR and IE do have some concern for the long term integrity l

• See Enclosure for identity of safe ends at each operating plant.

CONTACT:

W. J. Collins, TP 49-28180

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7 7 p rc o q q 3

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', B. K. Grimes 2

SEP 2 81978 l

t of these safe ends.

Type 4 safe ends have a more complex geometry which eliminatu the crevice or locates it away from the safe end wall, but does not eliminate stagnant water.

For BWR's operating and under construction which have Type 1, 2, 3 or 4 safe ends, resolution is needed in the areas of inservice inspection, me.iification, and design qualification.

RECOMMENDATRNS AND PROPOSED COURSE OF ACTION:

1.

'NRR will evaluate the basis for continued operation of affected plants including assurance that appropriate interim actions are taken.

2.

NRR will evaluate on a priority basis the need for installing

@celeromegd on a safe end at Duane Arnold and other units.

3.

IE will obtain refueling outage schedules from Type 3 plants and other plants as requested by NRR.

[4'.~ 'IE wi i nfom NRR and the NRC Pipe C c

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results of safe end inspections and metallographic examinations 7 q _they are obtained.

5.

E inspect for compliance with any requirements established CONCURRENCE:

hr S[LL[76 Edward L. Jordan, Assistavit Director Date for Technical Programs, DROI IE 9

e5. K. Grimes, Assistant Director j/ 7ky Date for t.:.cineering and Projecte. 10R, NRR 4

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e

-B. K. Grimes 3

SEP 2 9 p l

Enclosures:

1.

Recirc Inlet Nozzle Sutms:y 2.

PNO-78-163 cc:

R. S. Boyd, DPM -

V. Stello, D0R D. G. Eisenhut, DDR R. W. Reid, DDR W. S. Hazelton, DDR V. S. Noonan, DDR R. W. Klecker, DDR M. B. Fairtile, DDR J. G. Davis, IE N. C. Moseley, IE H. D. Thornburg, IE J. H. Sniezek, IE G. W. Reinmuth', IE B. H. Grier, RI J. P. O'Reilly, RII J. G. Keppler, RIII K. V. Seyfrit, RIV R. H. Engelken, RV K. Terney, MPA S. H. Hanauer, EDO R. J. Mattson, DSS

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s-PRELIMINARY NOTIFICATION i

September 14, 1978 O

PRELIMINARY NOT;FICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-78-163 This oreliminary notification constitutes EARLY notice of an event of POSSIELE safety or oubiic interest sien1ficance.

The information presentec is as initially receivec witncut verification or evaiuation and u casicaily ali inat is known ov IE staff on this cate.

Facility:

Iowa Electric Light & Power Company, Duane Amold (DN 50-331), Palo, IA

Subject:

JET PUMP RISER CRACK The jet pump riser crack problem at Iowa Electric Light and Power Company's Duane Arnold facility has been previously reported by PNO-78-125 and 12EA, dated June 19 and 20, 1978, respectively.

Metallographic samples were._..___

taken from the nozzles and sent to Battelle-Columbus and Southwest Research for examination.

Preliminary results obtained to date indicate that the cracks are inter-granular in nature and initiate in the area of the crevice formed by the thermal sleeve and inconel transition piece.

Carolina Power and Light Company's (CPLL) Brunswick Nuclear Plants i and l'

2 are similar in design and material fabrication to the Duane Arnold plant.

Due o the similarity, plans have been made for CP&L to concuct nondestructive examination of a selective number of nozzles for crack indications.

Brunswick Unit 2 is presently shutdown, and' testing will be conducted prior to its return to power.

There is some potential for the crack' problem to exist at other similar plants.

Th : probicm is currently being reviewed by the NRC staff.

These plants are:

Browns Ferry Units 1, 2, & 3 Dresden Units 2 & 3 Peach Bottom Units 2 & 3..

Quad Cities Uryi ts._1 &.2 __..

Contact:

WCollins, IE x2BlBO RWoodruff, IE 28180 GKlingler, IE x28180 b

Distribution:

Transmitted H St Chairman Hendrie Commissioner Bradford S. J. Chilk, SECY Commissioner Kennedy Commissioner Ahearne C. C. Karrenerer, CA Comissioner Gilinsky (For Distribution)

P Bida k J. G. Davis, IE Transmitted:

MNBB L. V. Gossick, ED0 "

,H. R.'Denton, NRR Region T 7 Ll M

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3 (p.IL) ry 44:4. 'g$

S. H. Hanauer, EDO J, 3. Fouchard, PA SS Bldg g -.,9.q gg N. M. Haller, MPA C. V. Smith, NMSS

.0. G. Abston, DIA p R. Minooue, SD%

zl_g R. G. Ryan, OSP l

H. K. Shepar, ELD

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t'RELIMINARY NOTIFICATION d

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I Pester Than Browns Ferry A 270* crack in ils reactor piping may have brought the Duane Arnold Nuclear Pla meltdown accident than did the renowned fire at the Browns Ferry Nuclear Plan' et by David Dinsmore Comey Electric will probably spen more than Until recently, the March 22,1975, fire.

panying photo.) As a result, the reactor

$15 million to purchase power liom was cooled down and the fuelin the re-at the Browns Ferry Nuclear Power Plant actor core was removed to the spent other utilities while the plant is shut ntar Decatur, Alabama, was the closest Radiographic and ultrasonic down.The Commission's chairman.Mor.

fuel po ris Van Nostrand, says he expects the i the American nuclear industry had come testing showed that, although the visible to a major accident at a civilian nuclear crack was four inches long, this crack utihty to make an " aggressive" attempt-i power plant. The fire destroyed the re-extended approximately 270 to recover repair costs from General cctor coritrol circuits, starting a "boit-

actuatl, Electric.

degree s around the circumference of off" of primary coolant in the reactor the pipe. When the other seven recircu-The original safe ends were manutac-core. At the same time,it disabled emer

• lation pipe safe ends were radrographed tured bv Lanape Forge in Pennsylvania.

psney core coohng systems Fortunate-and ultrasonically tested, all seven were under subcontract to Chicago Bridge ly, the " boil-ott" wee halted before a found to be cracked to some extent; four and iron, which in turn wr,s a subcon-core meltdown began?

had significant indicahons of intermit-tractor to General Electric, the reacts On June 17, 1978, however, the tent cracking around their entire circum-manufacturer. A drawing error ca : sed Duane Arnold Energy Center in Cedar feiences machinists at Lanape to cut a groom Rapids, Iowa, came closer - according As of this writing, all eight safe ends that was 3/8 of an inch too deep arouno -

to industry experts - to a " loss of-are scheduled to be replaced by newly each pipe. These grooves were then coolant" accident than did Browns Ferry designed forgings being faM#Cated at filled in with weld metal. Recoros at in 1975. This incident has received very Coulter Steel and Forge Company m Lanape, CB&l, and GE show that these little media attentiert Berkeley, California The plant cannot repairs were approved as meeting re r On June 17,1978, reactor operators De restarted before late October, and Quired safety codes.

were testing the control valves on the

.ne utility estimates that repair costs An NRC official says,"Ouite obvious.

Duane Arnold Center, a 538 megawatt will be about $2 million. The Iowa Com-ly we werer 't aware of the repai*s, a'ic boiling water reactor operated by lowa merce Commission eshmates that towa Electric Light and Power Company. Sud.

deniy because of problems wsth e(ectri-

,, ggg,,,,,,,n;,,,,,,,,,,, gn,,,,,g.s first nuclear shower Wa ter spurts from cal relays sn the reactor protection sys' pipe even after the reactor has been depressursted 3

tem,the reactor accidentally shut down.

a Only then,when an inspection of the re-j ccior dryweit was made, was it discov-

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cred that a primary coolant pipe was

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leaking from a four-inch long crack, The leaking pipe was one of eight 10-A inch diameter pipes used to transfer

• k>h %

s cooling water from the recirculation td o

system to the jet pumps inside the reac-f F, * *Q % \\ ',,

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tor, The crack was located in a section of the pipe known as a " safe end forg-

(d i

ing" that joins the pipe to the inlet nozzle

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on the reactor pressure vessel, This

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b,..!'5.h[

• sale end," located near the bottom of

1. [, O the reactor core,is a highly undesirable j j'/c' e

location at which to have a pipe break. A

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" design basis accident" analysis per-

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lormed by the U.S. Nuclear Regulatory

e' s,',,~ 7 7.*d D,,,,",,"~~~" $.d." /,7'(([,,',N[

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,T Commission (NRC) states that "a com-b plete circumferentiat break cf one of the recircutation 1000 pioes" would result in S,,,

- ?2.Y J,

N the worst " loss of coolant" accident I ,

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possible at a boshng water reactor.'

1. • h, g,.

i The leak continued even after the re-

.g-U actor was de pressurized. (See accom-

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l n

,/ l no one here is happy repaired parts Civil Liberties Confmred from pape 7.

less intrusive, "non-investigative safe-were used." But an NRC inspector says measures would be expensive. But nu-guard measures which would not under-that the repairs would have met even the clear facilities could be tumed into im-mine the Constitutional rights of nuclear more stringent safety codes in force to-pregnable "tortresses." 11 this were the industry employees."*

.I case, there would be no necessity of The ACLU position seems to be thatit day.

Because the three companies in-condu,cting Surveillance in order io be s possible to operate a major nuclear volved in fabricating the safe ends at aware 'of potential threats; any attack power program and still protect the ctvil Duane Arnold manufactured similar fit-could be repelled.

liberties of the people employed in this lings for the Brunswick Nuclear Plant piogram. But i disagree. Only thorough naar Wilmington, North Carolina, which "IS it better to torture a investigations will protect against the possibility of sabolage from within a nu-is owned by Carolina Power and Lighi, CBE has questioned whether Brunswirt suspected terrorist than to clear power plant and the loss of might not suffer the same problem as

]ct a City 90 Up in flames 7" hundreds of thousands of lives. This Du6ne Arnold. Because the safe end situation can be described in the sa ne w:lts at Brunswick are approximately terms used by Russell Ayres with re-Such measures would not, however, spect to a plutonium economy: To pro-one inch thick, however, while those at

• protect against the possibility that an lect the public it is necessary to deny Duane Amold are only '/rinch thick, the employee might smuggle in explosives the civil liberties of a significant seg-NRC believes that Brunswick shows no or os orride sately devices in such a way ment of the population.

cause for concern. Alt GE nuclear power as to cause a reactor to melt down or a plants other than Brunswick use a differ, waste. storage facility to disperse its cnt safe-end design from that at Duane radioactive contents over a wide area.

The ACLU Calls the NRC'S Amold.

in crder to protect against potential But it is worth noting that, at another sanotage from within the facility, the security pTOpOSals GE plant, approximately two months be.

NRC recently proposed an " accession alar TTling,"

u fore the incident at Duane Arnofd, an un.

authorization program" tot employees at scheduled inspection conducted on nuclear power plants. The program April 26,1978, during the romling of would include " background investiga.

Nuclear power thus represents a the Cooper Station of Nebraska Public tions as to character, associations, and threat to our civit liberties as greaf as Power south of Omaha discovered indi.

loyalty, conducted under standards and any other this country has faced The cations of cracking on three of the recir.

specifications established by the Com-many other drawbacks and hazards o!

culation loop pipes where the safe-end mission." Employees would be subject-nuclear power have become obvious is welds join the nozzles The delects ed to " full field background investiga' recent years. But on civil fibertieg

'were ground out without violating mini.

tions" by the Federal Bureau of in-grounds alone,fiuclear power deservec mal wall thickness codes. W the NRC vestigation and other agencies,in which to be abandoned.

has acwpted the repairs atisfacto.

past fellow employees, landlords, per-ry.

sonal and professional acquaintances, The NRC still does not know why the heiDhbors, and intimate personal rela-sale ends at Duane Arnold cracked,3 tions would be interviewed.Other meth-Footnotes

' David D. Comey, " Nuclear Power the Uit even though the repairs made to the im.

ods of investigation being discussed mate intemat Subversion". Decemoer 19 properly machined piping met both past wouto 5clude psychological testing, c

n add 55 oA ic and prese'nt code requirements.

clinical evaluation, and polygraph ex-D Fortunately.neither it'e Duane Amold

.. Die sonalen Zwknge der Kemenergie..

aminations.

or Cooper reactors were operating Mr. Shattuck,in his testimony on be-Kernenerg,e (Frankfurt am Main. Fischer Ve' wt, the cracks were discovered. We half of the ACLU.said that most of these lag.1976) pp 122-138

• David D Comey, "The Perlect Tro,a may not be so lucky the next time.

proposed measures are infringements or Horse / Buum of W Afornic Sem b

violations of protections now 9uaran-June 1976. p 34.

Details may be found in David D Comer, teed by the Constitution and by case 3 Russell W. Ayres, auoted in Chicapo Da News. Nov 29,1975, p 3 See atso r.

"The incident at Browns Ferry,' Not Man law. The NRC has estimated that more "Pobceng Plutonium The Cml libefUes FC Apart. September 1975, reprinted sn. Peter Taulkner (ed ), The S, lent Bomb (N Y., Ran-than 21,600 people will be subject to out." Harvard C,vis R,gnts - Curs levert-dom Hm,st 1977) such investigative clearances by 1985' Law Revoew,Vol 10.No 2 (Soring 197bL t

• Pretsminary Salery Analysts Report. Bailly and Mr. Shattuck characterized this 369 40 morents may be cotained for 53:

General,np Star,on Nuclear 1.p 14 612.

number as " alarming / He said. "The trom W,itiam S Hein. loc.,1285 Main Stre a The NRC has obtained one of the cracked Duffalo. NY 14209).

safe ends and sent it to Battene Memorial proposal would set a dangerous prece-

• Russell W. Ayres Quoted so Wash 4 Laboratory in Columbus. On,o for destructive dent by extending a security clearance posf. Nov 17.1975.0 A24

• John H F. Shattuck." Testimony of Ames lesting stat may reveal the cause of the cracking This testing will be an endependent government positions to an entire indus-Cmt Liberties Union " June B. 1978 000 check on the testing being performed for lows try, thereby broadly affecting the private No RM.50J. U S Nuclear Regulato y Cc mission. Wasnmpen Dr v 555 Electric at Southwest Research an San Anto-sector." He proposed that the NRC Seek n'o. T e8*s OCTOBER 191 r

.- 10

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