ML19338F377

Order Confirming Util Commitments to Implement Action Re IE Bulletin 80-17, Failure of 76 of 185 Control Rods to Fully Insert During Scram at Bwr

ML19338F377
Person / Time
Site:	Cooper
Issue date:	10/02/1980
From:	Stello V NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:	NEBRASKA PUBLIC POWER DISTRICT
Shared Package
ML19338F372	List: ML19338F371 ML19338F377
References
IEB-80-17, NUDOCS 8010200236
Download: ML19338F377 (7)

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. UNITED ST TES OF. AMERICA NUCLEAR REGULATORY COMMISSION In'the Matter of.

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Docket No.:

50-298

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Nebraska Public Power District.

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(Cooper. Nuclear Station)

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CONFIRMATORI ORDER I

Nebraska Public Power District (the " licensee") is the holder of Facility

' Operating License No.-DPR-46 (the " license") with an expiration date of June 4, 2008 which authorizes operation of the Cooper _ Nuclear Station (the " facility").

II On June 28, 1980, during a routine shutdown of the Browns Ferry Nuclear Power Station Unit 3 reactor, a manual scram from approximately 35% power failed to insert all of the control' rods. ~ Three scrams were initiated over a period of l

about 14 minutes to achieve full insertion of all of the control rods.

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The control rods:which failed to insert were-all located on the east side of the reactor core.

Investigation indicated that this was caused by water unknowingly accumulating ~inithe east: side scram discharge volume (SDV).

This accumulation i

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. reduced the available free volume for scram water discharge and inhibited control rod. insertion.

It is believed that an obstructed vent and/or drain' caused the

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accumulation of water.

This accumulation of water was not detected by the l

reactor protection-system-because it~ stayed within the-SDV headers and did not drain to the scram di.scharge instrumented volume '(SDIV).

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2-w On July 2,11980, a: team of NRC-Headquarters representatives went to the Browns

- Ferry site-to gather detailed information on the' event and its related considera-tions. 'IE Bulletin No. 80-17,. " Failure of 76 of 185 Control Rods to Fully. Insert During a Scram;at a BWR" was issued on July 3,1980 and requested actions to-be taken by all licensees of operating General Electric designed Boiling Water:

Reactors.

Among the actions requested were the following:

"1.

Within 3 days ~_from the date of this Bulletin, perform surveillance tests to verify that there is no significant amount of water in the Scram Discharge. Volume (SDV) and associated piping and that the SDV vent valves are operable and vent system.is free of obstruction."

"3.

.At-the conclusion of the scram tests and all other scrams, verify that all vent lines in the SDV are functional.

Verify that there is. no:significant amount of water in the SDV and associated piping."

"5.

' Review and develop surveillance procedures such that scram discharge i

volume is monitored daily for residue water for 6 days and, if results are acceptable, the interval may be extended to 7 days."

Additional' actions applicable to these 3WR. facilities were requested in Supplement Nos. 1, 2, and 3 to IE Bulletin 80-17; these supplements.were issued

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on July 18, July 22 and August 22, 1980, respectively.

Specific actions were

requested with regard to the unobstructed venting and draining of the SDV.

In particular, Item B.1'of Supplement 1 requested the following:

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E " B.- Actions to'.bs Taken by BWRJLicenseesiand Completed by September 1,

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1980:

1)L Install' a: system to continuously monitor' water levels in all 1

scram discharge' volumes.

Continuous recording..id alarm features.must be' included.in the design.. Consideration'should-be given to use ofLdiverse level sensors 'in this (these) system (s).

The. design install,ed shouldIrepresent the~ design with the highest

' level sof reliab'ility compatible with. completion of installation by~ September.1,-1980. l Provide a written description of the

. system de' sign to the NRC Regional Office.

4.

LIfiinstallation'by September 1, 1980 is notlpossible, by August 15, 1980, submit to the NRC Regional'Officei 1)

.Do'cumentation.in detail why the installation cannot be completed I

by September 1, 1980.

2)

A commitment to a firm schedule for installation.

-3)

A commitment to equipment changes and/or surveillance requirements Lin addition'to-those now in effect that will provide adequate assurance of-.SDVioperability.in the interim until installation -

is' completed 2".

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- The licensee responded to.this' request in Supplement lito the Bulletin by letter dated August 15, 1980.

This' response.was unacceptable on the basis that it did not provide' adequate assurance that the licensee could' maintain scram capability at all times during current operation..The Bulletin and its-Supplements were issued ~ to provide such assurance during an interim period of-operation until an -

ultimate resolution is achieved by changes in system design and operating procedures.

In view of the foregoing considerations the NRC staff has concluded that partic-ular criteria must be. satisfied in order to provide adequate justification ror continued. operation.

Criteria applicable to the licensee's facilities are set forth in Sectien'III.'

These criteria reflect NRC judgement that continuous monitoring of the SDV with appropriate indication and alarm'in the control room-is to be completed noLlater than specified.

Until the installation is complete

.n and operable, surveillance checks of the SDV shall be made at least once per shift whenever the reactor is critical.

These matters were the subject of the discussions between NRC'and licensee representative Mr. L. Lessor on September 8, 1980. The discussions provided the information'on which the licensee made further commitments-to satisfy the

' requests 'of the Bulletin and its supplements.

These commitments were documented by letters dated September 11, 1980 and September 18, 1980' from the licensee.

-In view of.the,importance of these commitments to safe' operation of the-facility, it is appropriate to confirm the licensee's commitments by order.

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III Accordingly, pursuant to the Atomic-Energy Act of 1954, as amended, and:the Commission's regulations in 10 CFR Parts 2 and 50, IT IS-HEREBY ORDERED,

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EFFECTIVE'IMMEDIATELY,.THATi 1.

By December.1,_1980, the. licensee shall:

a)

Install and make operable a system to continuously monitor water levels in all scram discharge volumes (SDV).

.b)

The installed system shall provide for level-indication, with an associated alarm, in the control room, for each SDV.

This equipment shall provide sufficient information to the reactor operator such that if water accumulates in either SDV the decision about actions to be taken can be made in a timely fashion from.the control room.

-2.

Until.the system. described in III.1 is installed and operating satisfac-

!torily the licensee shall increase surveillance of the SDV water level to

.at least once.per shift. -The once per shift surveillance checks shall be at least 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> apart.

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.The licensee shallfsubmit a report-to the Director, Reactor Operations Inspection,. Washington,.D.C.:20555 and to the Director of the appropriate Regional Office, confirming-installation of the continuous water level monitoring system, with provisions for in'dication and alarm in the control room, at.the time the installation is completed.

IV

- Any person.who has'an interest affected by this Order may request a hearing.

within twenty-five (25)' days of the date of the Order.

Any request for a

- hearing will not stay the effectiveness of this Order.

Any request for a hearing shall. be submitted to the' Secretary, U.S. Nuclear Regulatory Commission,

- Washingtc-, D.C. 20555 with a copy to the Executive Legal Di' rector at.the same address.

A request' for a hearing should ~ describe specifically the manner in

.'which the petitioner's' interest is affected by this'0rder and should address the criteria set.fortii,in:10 CFR 2.714(d).

If a hearing is requested by a

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person who has an: interest affected by this Order, the Commission will_ issue an order designating the time ani place of any such hearing.

If a hearing is' held, the issue.to be. considered at such a hearing shall be whether the licensee should perform the actions required in Part III of this Order in accordance with the schedule stated'therein.

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Operation lof-the~ facility _on' terms.consisteilt with-this Order-is-not stayed by

- the pendency'of'any? proceeding'on the Order. -

u FOR THE NUCLEAR REGULATORY. COMMISSION fA

- Victor Stello, Jf.

Director Office of Inspection and Enforcement Effective' Data: OCT 2 1980 Bethesda~,-Maryland e

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If a hearing-is' held,.the issue to be. considered at such a hearing shall be f

jwhether the licenseeishould perform the actions required in Part III of this

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forder in.accordance with the schedul_e. stated therein.

Operation ~of the; facility.on terms consi~ stent with this. Order is not stayed by

..the pendency.of any proceeding on the Order.

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i FOR-THE NUCLEAR REGULATORY COMMISSION M

Victor Stello, Jr. F.

Director.

t Office 'of Inspection and Enforcement' Effective Date: GCT 2. :1950 Bethesda, Maryland-1 9

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