A800039, Responds to Item a in IE Bulletin 80-17,Suppl 1, Failure of 76 of 185 Control Rods to Fully Insert During Scram at Bwr. Analysis & Review of as-built Scram Discharge Vol & Associated Vent & Drain Sys Is Completed

Responds to Item a in IE Bulletin 80-17,Suppl 1, Failure of 76 of 185 Control Rods to Fully Insert During Scram at Bwr. Analysis & Review of as-built Scram Discharge Vol & Associated Vent & Drain Sys Is Completed

ML19340B114
Person / Time
Site:	Cooper
Issue date:	08/12/1980
From:	Pilant J NEBRASKA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19340B113	List: ML19340B112
References
IEB-80-17, LQA8000390, NUDOCS 8010210280
Download: ML19340B114 (3)

Text

~

LQA8000390 N

COOPER NUCLEAR STATION sk Nebraska Public Power District

" 9*&*E MDM; E "_.^f^ "_'

y _. __ __.

'ust 12,1980 Mr. Karl V. Seyfrit, Director U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region IV 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011

Subject:

IE Bulletin No. 80-17, Supplement 1 Failure of 76 of 185 Control Rods to Fully Insert During a Scram at a BWR

Dear Mr. Seyfrit:

This letter is written in response to Item A requirements of the first supplement to IE Bulletin No. 80-17.

As indicated to you in our letter dated August 11, 1980, our response was delayed so that we could submit the "as-built" conditions for the check valves installed on August 8, 1980.

A1.

Response

A review of the "as-built" SDV system and associated vent and draic systems has been completed.

An analysis with respect to the design and functional adequacy of these systems has been performed in-cluding the following parameters:

1.

Calculated volumes and measured volumes.

2.

Continuous sloped SDV baader and drain line.

3.

Functional vent and drain valves including a check valve (vacuum breaker) on each vent valve.

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

This provides a redundant vent path through the check value (vacuum breaker) to the vent velve.

Based on the above analyses and the test results mandated by IE Bulletin No. 80-17, NPPD considers the "as-built" configuration of the SDV system and the associated vent and drains to be adequate with respect to the existing design criteria.

No design and/or installation deficiencies have been identified.

S 010210MO

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

Enclosed for your review are the following drawings reflecting verified "as-built" pipe and component configurations, including the new parallel check valve (vacuum breaker) installation.

RS185778 2" ANSI 600# SW 70-27-1 DRTS Control Valve (SDV Drain Valve)

RS185777 1" ANSI 600# SW 70-27-1 DRT Control Valve (SDV Vent Valve) l B&R 2039 Control Rod Drive Flow Diagram SK-5-27-71 Scram Header Isometric CP-009 CRD H.S. Hangers CP-002 1 of 3 CRD H.S. General Arrangement CP-007 CRD H.S. Scram Monitoring Station 27IS-10 Reactor Building Drain Pipe Isometric 27IS-22 Reactor Building Drain Pipe Isometric CP-001 1 of 1 CRD H.S. Diagram B-51063 Vogt Swing Check Valve (SDV Vacuum Breaker)

NPPD CRD Discharge Pipe Composite Isometric NPPD Scram Monitoring Station Composite Isometric The above drawings were given to the NRC representative at the Region III/IV meeting in Chicago on July 30, 1980.

These drawings did not reflect the parallel check valve (vacuum breaker) instal-lation.

A2.

Response

Our present operating procedures provide clear guidance to the licensed operator in the control room regarding when he should initiate the SLCS without obtaining prior supervisory approval.

No procedure revisions are required.

A3.

Response

Procedures exist which require the SDV be drained if water is found in the SDV system. The procedures also stipulate that station management be notified and that if the volume cannot be drained, the reactor should be shutdown by inserting control rods.with the reactor manual control system.

A4.

Response

i Our present operating procedures ensure.that the SLCS key is im-mediately available to the licensed control room operator. The key is-kept~in an unlocked key' cabinet near the control room operator's desk.

.Mr. Karl V. Seyfrit August 12, 1980 Page 3.

AS.

Response

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

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

Sincerely, s

J.

. Pilant Director of Licensing and Quality Assurance JMP:LCL:cg l

cc:

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

Office of Inspection & Enforcement Division of Reactor Operations Inspection Washington, DC 20555 1

i t

[

l-f I

s e

r

~

n

- r