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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o..' - Date: SEP 2 91978 SeH al ~ No. : IE:ROI: 78-10 TRANSFER OF LEAD RESPONSIBILITY 0

.T,0,:

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

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 of s 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 6 O, by independent laboratories under contract to the licensee and IE.

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. (/v 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 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

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

5. E inspect for compliance with any requirements established CONCURRENCE:

Edward L. Jordan, Assistavit Director hr S[LL[76 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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-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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PRELIMINARY NOTIFICATION

,- . September 14, 1978 i

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.

l' Carolina Power and Light Company's (CPLL) Brunswick Nuclear Plants i and 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 Distribution: Transmitted H St b Commissioner Bradford S. J. Chilk, SECY Chairman Hendrie C. C. Karrenerer, CA Commissioner Kennedy Commissioner Ahearne Comissioner Gilinsky (For Distribution)

Transmitted: MNBB P Bida k J. G. Davis, IE L. V. Gossick, ED0 "

~

,H. R.'Denton, NRR Region T 7 Ll M S. H. Hanauer, EDO 3

J, 3. Fouchard, PA SS Bldg g - .,9.q (p.IL) ry gg 44:4. 'g$,

N. M. Haller, MPA C. V. Smith, NMSS .0. G. Abston, DIA p R. G. Ryan, OSP R. Minooue, SD H. K. Shepar, ELD

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% zl_gl t'RELIMINARY NOTIFICATION

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I Ferry Pester Than Browns 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 panying photo.) As a result, the reactor '

Until recently, the March 22,1975, fire. $15 million to purchase power liom at the Browns Ferry Nuclear Power Plant was cooled down and the fuelin the re- other utilities while the plant is shut ,

actor core was removed to the spent ntar Decatur, Alabama, was the closest Radiographic and ultrasonic down.The Commission's chairman.Mor. ,

fuel po the American nuclear industry had come ris Van Nostrand, says he expects the i testing showed that, although the visible to a major accident at a civilian nuclear utihty to make an " aggressive" attempt-crack was four inches long, this crack i power plant. The fire destroyed the re- to recover repair costs from General actuatl, extended approximately 270 cctor coritrol circuits, starting a "boit- 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 ly, the " boil-ott" wee halted before a under subcontract to Chicago Bridge 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-On June 17, 1978, however, the tractor to General Electric, the reacts tent cracking around their entire circum- manufacturer. A drawing error ca : sed Duane Arnold Energy Center in Cedar Rapids, Iowa, came closer - according feiences machinists at Lanape to cut a groom 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 coolant" accident than did Browns Ferry each pipe. These grooves were then designed forgings being faM#Cated at in 1975. This incident has received very filled in with weld metal. Recoros at Coulter Steel and Forge Company m Lanape, CB&l, and GE show that these little media attentiert Berkeley, California The plant cannot On June 17,1978, reactor operators repairs were approved as meeting re r De restarted before late October, and Quired safety codes.  !

were testing the control valves on the .ne utility estimates that repair costs Duane Arnold Center, a 538 megawatt An NRC official says,"Ouite obvious.

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

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leaking from a four-inch long crack, ,

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The leaking pipe was one of eight 10- s A inch diameter pipes used to transfer

• k>h % o cooling water from the recirculation td '% ,

system to the jet pumps inside the reac-

• tor, The crack was located in a section f F, * *Q % \ ', , -l j,'y ',8p \

of the pipe known as a " safe end forg- i ,

(d ing" that joins the pipe to the inlet nozzle N- .f g .

on the reactor pressure vessel, This ,N r -:,n.!

• sale end," located near the bottom of the reactor core,is a highly undesirable j j'/c' b , ..!'5.h[

e

1. [, O location at which to have a pipe break. A i

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" design basis accident" analysis per- 4  %' :.,,,, ,

lormed by the U.S. Nuclear Regulatory . .

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Commission (NRC) states that "a com-b e' s,', ,~ 7 7.*d# "I -(*

,T D,,,," ,,"~~~" $.d." /,7'(([,,',N[

plete circumferentiat break cf one of the S , ,,

recircutation 1000 pioes" would result in J, N - ?2.Y the worst " loss of coolant" accident I , .[,

i possible at a boshng water reactor.' #* h, U g,..g- ,,,

The leak continued even after the re-actor was de pressurized. (See accom-

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,/ l Civil Liberties Confmred from pape 7. less intrusive, "non-investigative safe-no one here is happy repaired parts guard measures which would not under-were used." But an NRC inspector says measures would be expensive. But nu-mine the Constitutional rights of nuclear that the repairs would have met even the clear facilities could be tumed into im-pregnable "tortresses." 11 this were the industry employees."*

more stringent safety codes in force to- .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 could be repelled. liberties of the people employed in this Duane Arnold manufactured similar fit-lings for the Brunswick Nuclear Plant piogram. But i disagree. Only thorough naar Wilmington, North Carolina, which investigations will protect against the is owned by Carolina Power and Lighi, "IS it better to torture a possibility of sabolage from within a nu-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, one inch thick, however, while those at spect to a plutonium economy: To pro-

• 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 cause for concern. Alt GE nuclear power ment of the population. -

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.

Amold. in crder to protect against potential The ACLU Calls the NRC'S 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 u alar TTling,"

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 Footnotes tions would be interviewed.Other meth-even though the repairs made to the im. ods of investigation being discussed ' David D. Comey, " Nuclear Power the Uit properly machined piping met both past wouto 5clude psychological testing, mate intemat Subversion". Decemoer $$

197 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 lag.1976) pp 122-138 half of the ACLU.said that most of these

• 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 "The incident at Browns Ferry,' Not Man News. Nov 29,1975, p 3 See atso r.

Apart. September 1975, reprinted sn. Peter law. The NRC has estimated that more "Pobceng Plutonium The Cml libefUes FC 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 369 40 morents may be cotained for 53:

• Pretsminary Salery Analysts Report. Bailly and Mr. Shattuck characterized this 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 proposal would set a dangerous prece- Duffalo. NY 14209).

safe ends and sent it to Battene Memorial

• 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 lesting stat may reveal the cause of the ,

• John H F. Shattuck." Testimony of Ames 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 No RM.50J. U S Nuclear Regulato y Cc try, thereby broadly affecting the private 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

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