ML19331C715

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Responds to IE Bulletin 80-17,Suppl 1, Failure of 76 of 185 Control Rods to Fully Insert During Scram at Bwr. Design & Functional Adequacy of Check Valve & Associated Vent & Drain Sys Analyzed.Deficiencies Not Identified
ML19331C715
Person / Time
Site: Cooper Entergy icon.png
Issue date: 08/12/1980
From: Pilant J
NEBRASKA PUBLIC POWER DISTRICT
To: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
IEB-80-17, LQA8000390, NUDOCS 8008190430
Download: ML19331C715 (3)


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LOA 8000390 CCopER NL. CLcAR STATION P.o. Box 18. SRoWNVILLE. NESR ASKA 63321 Nebraska Public Power Distr. t ic reLt~o~c oui m.:m August 12, 1980 Mr. Karl V.

Seyfrit, Director U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region IV 611 Ryan Pla:a Drive Suite 1000 Arlington, Texas 76011

Subject:

II Sulletin.No. 30-17, Supplement 1 Failure of 76 of 185 Control Rods to Fully Inser: During a Scras at a 3WR

Dear Mr. Seyfri :

This letter is written in response to I:es A requirements of the first supplement to IE Bulletin No. 30-17.

As indicated to you in our let:er dated August 11, 1980, our response was delayed so that we could submi:

the "as-built" condi: ions for :he check valves installed on August 8, 1930.

A1, Respense e

A review of the "as-built" SDV systen and associated vent and drain systens has been co=pleted. An analysis with respect to the design and functional adequacy of these sys:e s has been perfor=ed in-cluding :he following parace:ers:

1.

Calculated voluces and =easured volumes.

2.

Continuous sloped SDV header and drain line.

3.

Func:icnal vent and drain valves including a check valve (vacuu: breaker) on each ven: valve.

An additional check valve was installed in parallel wi:h the ex-isting check valve associated with each vent valve.

This provides a redundant vent path through the check valve (vacuu breaker) to the ven: valve.

3ased on :he above analyses and the test results =andated by II 3u11etin No. S0-17, NPPD considers the "as-built" configuration of the SDV system and the associated vent and drains to be adequate with respect :o the existing design criteria. No design and/or 0\\

installation deficiencies have been identified.

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8008190 qg

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Mr. Karl V. Seyfri August 12, 1980 Page 2.

Inclosed for your review are the following drawings reflecting verified "as-buil:" pipe and co=ponent configurations, including the new parallel check valve (vacuus breaker) installation.

RSlS5778 2" ANSI 6001 SW 70-27-1 DRTS Control Valve (SDV Drain Valve)

RSlS5f77 1" ANSI 600# SW 70-27-1 DRI Control Valve (SDV Vent Valve)

B&R 2039 Control Rod Drive Flow Diagram SK-5-27-71 Scram Header Isometric C?-009 CRD H.S. Hangers CP-002 1 of 3 CRD H.S. General Arrange =en:

C?-007 CRD H.S. Scram Monitoring Statica 27IS-10 Reac:or Building Drain Pipe Iso =etric 27!S-22 Reac:or Building Drain Pipe Iso =etric C?-001 1 of 1 CRD H.S. Diagras 3-51063 Vogt Swing Check Valve (SDV Vacuum 3reaker)

N??D CRD Discharge Pipe Co=posi:e Isometric NPPD Scram Monitoring Sta: ion Composite Isometric The above drawings were given to the NRC representative at the Region III/IV =eeting in Chicago on July 30, 1980. These drawings did not reflect the parallel check valve (vacuum breaker) instel-lation.

A2.

Response

Our present operating procedures provide clear guidance to the licensed opera or in the control roo regarding when he should initiate the SLCS wi:hout obtaining prior supervisory approval. No procedure revisions are required.

A3.

Resconse

?rocedures exist which require the SDV be drained if water is found in the SDV system. The procedures also s:1pulate that station

=anagement be notified and that if the volu=e cannot be drained,

he reactor should be shutdown by inser:ing control rods with the reactor =anual control system.

A4.

Response

Our present operating procedures ensure tha: the ZiCS key is i=-

mediately available to the licensed con:rol roo= operator. The key is kept in an unlocked key cabinet near the control :com operator's desk.

y-o Mr. Karl V. Seyfrit August 12,.980 Page 3.

AS.

Response

The scram discharge volumes are being monitored for water levels daily.

If you have any questions concerning this subject, please contact me.

Sincerely, 4

J... F11 ant Director of Licensing and Quality Assurance JMP:LCL:cg cc:

U.S. Nuclear Regulatory Commission w/o encl.

Office of Inspection & Enforcement Division of Reactor Operations Inspection Washington, DC 20555 i

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