ML20126A353

Petition/Request for Order to Show Cause Why Plants Should Not Be Shut Down Until CRD Mechanisms Inspected

ML20126A353
Person / Time
Site:	Oconee, Arkansas Nuclear, Three Mile Island, Crystal River, Rancho Seco, 05000000
Issue date:	06/11/1985
From:	Doherty J DOHERTY, J.F.
To:	Office of Nuclear Reactor Regulation
References
CON-#385-484 2.206, NUDOCS 8506130316
Download: ML20126A353 (6)

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Juno 11, 1985 s

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION Before the Director of Nuclear Reac-tor Regulation In the Matter of:  ;

ARKANSAS POWER & LIGHT CO. Docket No. 50-313 (Arkansas Nuclear One Station, Unit 1)

SACRAMENTO MUNICIPAL UTILITY DIST. Docket No. 50-312 (Rancho Seco:St'at19n, Unit 1) f i

FLORIDA POWER CORP. Docket No. 50-302 (Crystal River Station, Unit 3) f DUKE POWER CORPORATION l Docket Nos. 50-269, (Oconee Station, Units 1, 2, & 3) .l 50-270, 50-287 GENERAL PUBLIC UTILITIES NUCLEAR CORP. [ Docket No. 50-289 (Three Mile Island Station', Unit 1) j JOHN F. DOHERTY'S PETITION /REQUE3T FOR SHOW CAUSE ORDER Pursuant to 10 CFR 2.206 of the Commission's Rules of Practice, John F. Doherty, of 318 Summit Ave., Apt. #3, Brighton, Massachusetts 02135, (617) 232-3853, now files this Petition / Request for Show Cause Order under 10 CFR 2.202, to the Director of Nuclear Reactor Regulation, seek-ing that the Director institute a consolidated proceeding or proceedings to suspend or revoke the operating license for the Arkansan Nucinar One Station, Unit 1; Rancho Seco Station _, Unit 1; Crvntal River 8tntion, Unit 3; Oconee Sta-tions, Units 1. 2 & 3; and Three Mile Ininnd Station.

Unit 1, by serving the respective Licensees, Arkansas Power

& Light Co., Sacramento Municipal Utility District, Florida Power Corporation, Duke Power Corporation, and General Pub-lic Utilities Nuclear Corporation,an Order to Show Cauce why the said operating Licensee should not have ito Operating Licence ausponied or revoked until such time that it inopoets DR k 9 g

and (based on the result of the inspection) corrects its facilities for the hazardous condition exclained below.

Basis for the Petition / Recuest:

The basis for this request for action is from Inspection and Enforcement Notico No. 85-38.2-[ dated May 21, 1985, and received by Petitioner on June 1, 1935, and addressed to all utilities holding an operating licenso for nuclear pow-er facilities designed by the Babcock & Wilcox Corporation (B & W). All auch facilities are pressurized water reactors (PWRs) having control rods above the fuel zone in the reactor proasure vesaol. As doacribed in Notice No. 85-38, the Davis-Bosse Nuclear Plant, a B. & W. PWR, on inspection fol-lowing the failure on two occainions (March 16, 1985 and March 21, 1985) for its control rod E-3, revealed a broken locking noring in the control rod drive mechanism (CRDM) at core location M-5, and four locking coringa not in their nor-mal and correct locking position. The CRDM at location E-3 had shown a brokon locking soring and not all pieces of the spring were believed recoverod. In addition, pieces described no from a maintainanco tool used the previous year were found in the CRDM. It thus appears the CRDMS at locations E-3 and M-5 at Dnvin-Bonne had broken locking aprings in them and that the CRDM's at E-3 and C-7 (alao noted in Notico No. 85-38) have both boon blocked (at difforont times) by a common mode phenomena.

NTitled, "Loono Parta Obatruct Control. Rod Drivo Mechantom" (Attached)

From these facts, it is clear the Davis-Bonne plant might well have had a SCRAM in which two control rods could not have been driven into the core due to jamming of the CRDMs by loose parts such~as'.those de-scribed in the notice. The usual technical opocifica-tions or Commission Regulatory Guides recuire that it be nossible to bring the reactor core sub-critical with a single control rod stuck fully out. However, in the case where two control rods are stuck out it apponra it may not be possible to bring the core to sub-criticality without the uso of a back up cystem auch no one designed to introduce boron into the cir-culating coolant in greator unntity than in normal onoration.

Notico No. 85-33 states that tho, "oprinc failuros are considered to be a notontial common mode failure that could affect the reactor trip function becauco

. . . (of) (2) the liklihood for out-of-position springs to be broken when the control rod is fully withdrawn; and (3) the notontial for a broken anring to cause the con-trol rod to jam."S! Thin noint (3) ovidently incluien damaing when n rod in signaled to drop or enter the fuel zono in rosponno to an anticipated oporating tranniont auch no a turbino stop, hirh atoam generator water lovel, lona of foodwater heator, recirculation pump trip, high flux nignal,or main ntoam isolation valvo closure.

N N otico No. 95-33, pago 2.

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Common mode failures are of great concern if they may compromize the automatic reactor protection system of a PWR. A common mode failure in an agtomatic reactor

. protection system was found at the Kr.hl (VAK) reactor, a Boiling Water Reactor, in July of 19G5. There a bon-ding. agent on scram relays became sticky after two weeks of use and a " routine test revealed.that there had been a period of time in which 80 RAM would not have been ini-tiated if it had been required.*YI The concern here is that in the interval required to stop fissioning through the redundant means available, the transient excess reac-tivity in the core will result in local fuel melting.

The possibility of two adjacent control rods falling to insort, while somewhat remote in a two rod insertion fail-ure due to CRDM damming, would cause the mont severe fuel melting with'that level of rod insertion failure.

It in evident from Notico No. 85-38, that the springs may break or relocate in an CRDM in any of the B. & W.

plants subject in this Petition / Request, and evidently no incoectionn for broken or dislocated springs which might dam the deacont of a control rod into a PWR core have been made in the current operating D. & W. plants other than the Davin-Bonne Nuclear Plant. Nor to it, in view of the i conditions found at thnt plant, an unronconablo suspicion f

that an upcoming 80 RAM (one prior to the next schoduled outage) may well produce a more than one rod out of the i

/" Technical note: The Kahl Rolay Common Molo Failure",

j Nuctent Snretv, Vol. 20(9), Gopt-Oct. 1979, pp. 979-81 t

a core situation. It is a sensible caution to realize two or more rods stuck out of the core in a severe op-erating transient might well produce a local fuel melt carticularly if the rods are contiguous or nearly so.

While true a boron introducing system may be ex-nocted available as a back up to the SCRAM system, Gen-eral Design Critorien 26(10 CFR 50, Appendix A, Criterion

26) would appear to require both those systems, (SCRAM and back-up) be fully available to protect against. reno-tivity insortion. In addition, the Critorion cortainly strongly auggests that oporation with one system reasonably nunoccted to be not fully catablo of performing its full task would violate that Critorion.

Moroover, permitting continued operation of those B. & W. planto doapite the jamming problem described in Notice No.85-38, would appear contrary to General Donign Critorion 29 (10 CFR 50, Appendix A, Critorion 29). If those plantn continuo in operation the probability of the orotection and roactivity control systoma accompliching their enfety functiona in decroaced in the face of a more than one rod jammed out by CRDM parts aituation as descri-bed in Notico No. 85-38. By requiring the utility owners (Liconnoon) of the aforomantioned D. & W. planta to elim-innto thin enuno of jamming would bring the planto in clocarconnliancowithGeneralDonirnCritorion29.k!

b/ Critorion 26 and 29 aro unoi hero in the nonno that they show good prnetico. The nubject pinnta woro believed dentennd in como11anco with the two critorin and it mnkon conse the planto should oporato only whilo fully providing what the critoria call for for functioning plant hardwaro.

Conclusion Based on the information provided in Information and Enforcement Notice No. 85-38 and other material in this Petition / Request, Petitioner heroby requests the Director of Nuclear Reactor Regulation to issue an order reruiring these 5 Licensees to show cause 4

why the nuclear plants under their control should not be shutdown until such time as an inspection (and re-pairs as indicated)of the Control Rod Drive Mechanisms is accomolished, be issued.

Rospectfully,

& k/

John F. DohertY l

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SSINS No.: 6835 IN 85-38 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 , l May 21, 1985 IE INFORMATION NOTICE NO. 85-38: LOOSE PARTS OBSTRUCT CONTROL R00 DRIVE MECHANISM Addressees: ,

All utilities with pressurized water reactor (PWR) nuclear power facilities designed by Babcock & Wilcox (B&W) and holding an operating license (OL) or a  :

construction permit (CP).

Purpose:

This information notice is provided to alert recipients of a potentially significant problem pertaining to loose parts that can obstruct and prevent motion inside of control rod drive mechanisms . It is expected that recipients ,

will review the information for applicability to their facilities and consider actions, if appropriate, to preclude a similar problem occurring at their '

facj]ities. However, suggestions contained in this information. notice do not constitute NRC requirements; therefore, no specific action or written response  ;

is required. >

Description of Circumstances:

In 1981 at the Davis-Bes Nuclear Plant. a larHno swing brea in a control end driva mechanism M) in c57'b locatinn (-T and Dec,ame wedoed against the .

cantfroi rod, > c,codity II trom'uperanno. The cause was not determined at '

that time. UGTthg'the 1984 outage, the locking springs were inspected and none appeared broken or. in the wrong position. On March 16, 1985, the control rod in core location 6 3 would not drop into the core on demand and had to be driven downward by Ttintrol room personnel. This control rod was tested during an outage on March 21, 1985, andjammedafterthreecyclesofoperation.

InsideofthisCRDMwereforeignobjectsandabrokenlockingspring. The foreign objects were pieces of a set screw from the handling tool used during the 1984 outage that had lodged in the CRDM and prevented the drive screws from being disengaged. The locking spring (a flat tee-shaped device with a riveted 1 tab) was broken at the tee and the upper rivet hole. The upper portion of the <

broken spring was not found and is believed to be inside of the CRDM. .

Further examination of all of the mechanisms revealed a broken locking spring i in core location H4. In addition four springs were not in their normal locking position. DuringUpt!rationthereIsnomeansofdetectingbrokenspringsor foreignobjectsintheCRDM. Exercising the control rod will allow loose pieces to move.

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IN 8a-38 May 21, 1985 Page 2 of 2 i

The most likely cause of the spring failures is that the unit went into service with some of the locking springs not in their correct position. The present assembly procedure has the maintenance technician determining that the spring i is in the correct position by " feel" through a long handling tool. If this

! process is not successful, the reactor will be placed in operation with the i spring out of position. -When the control rod is fully withdrawn, an out-of-position spring will hit the inside of the torque tube cap and snap when sufficiently loaded. This was confirmed by the appearance of the spring failures which were brittle, intergranular fractures. In addition, examination of the inside of the cap showed a gouge in the tapered portion near the bottom and an indentation on the bottom surface.

Spring failures are consideteo to be a potential common mode failure that could atfect the reactor trip function because (1) four springs at Davis Besse were found not to be in their normal position and two others were broken; (2) the likelihood for out of uus(*fon springs to be broken when the control rod is fully withdrawn; and ( O the potential for a broken spring to cause the control rodtojam.

1pe corrective action by Davis-Besse Nuclear Plant was to ieplace all of the

et-of position spring assemblies and to verify by visual examint. tion that the l rings were in their correct positions. Consideration is being given to ding this verification as a regular part of the maintenance procedures. The.

W Owners Group has notified their members that there were 'alled locki.og-springs at Davis-Besse in the control rod drive mechanisms.

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the Regional Administrator of the appropriate regional office or this office.

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IdwarhL.Joroan, Director Divis on of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement Technical

Contact:

P. Cortlara. II 301 492-4175

Attachment:

List of kecentij 1ssueo IE Infoi n ttoo untices

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Attachment 1 L IN 85-38 May 21, 1985 LIST OF RECENTLY ISSUED IE INFORMATION NOTICES Information Date of Notice No. Subject Issue Issued to 85-37 Chemical Cleaning Of Steam 5/14/85 All pressure water Generator At Milestone 2 reactor facilities holding an OL or CP

, 84-55 Seal Table Leaks At PWRs 5/14/85 All power reactor Sup. l' facilities holding an OL or CP 85-20 Motor-0perated Valve Failures 5/14/85 All power reactor Sup. 1 Due To Hammering Effect facilities holding an OL or CP 85-36 Malfunction Of A Dry-Storage, 5/9/85 All licensees l Panoramic, Gamma Exposure possessing gamma -

Irradiator irradiators 84-52 Inadequate Material 5/8/85 All power reactor ,

Sup. 1 Procurement Controls On facilities holding '

The Part Of Licensees And ' '

an OL or CP Vendors ,

s 85 Failure Of Air Check Valves 4/30/85 All power reactor To Seat facilities holding  :

an OL or CP 85-34 Heat Tracing Contributes To 4/30/85 All power reactor  :

Corrosion Failure Of Stainless facilities holding Steel Piping an OL or CP

) 84-84 Deficiencies In Ferro- 4/24/85 All power reactor i Rev. 1 Resonant Transformers facilities holding :

an OL or CP i

85-33 undersized Nozzle-To-Shell 4/22/85 All power reactor  !

Welded Joints in Tanks And facilities holding Heat Enchangers Constructed an OL or CP Under The Rules Of The ASME Boller And Pressure Vessel Code 65 'd Recent Engine Failures Of 4/22/85 All power reactor Emergency Diesel Generators facilities holding r an OL or CP f

OL = Operating License l CP

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