05000369/LER-1981-080, Forwards LER 81-080/03L-0.Detailed Event Analysis Encl

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Forwards LER 81-080/03L-0.Detailed Event Analysis Encl
ML20009G068
Person / Time
Site: McGuire 
Issue date: 06/05/1981
From: Parker W
DUKE POWER CO.
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009G069 List:
References
NUDOCS 8108030300
Download: ML20009G068 (3)
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LER-1981-080, Forwards LER 81-080/03L-0.Detailed Event Analysis Encl
Event date:
Report date:
3691981080R00 - NRC Website
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OFFICIAL co; y DUKE POWER COMPANY q.

Powra Ut:stotxo 520 Sourn Cnunen STREET. CIMHIDTTE. N. C. 28242

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/*CF P#f M OEN T TEL E PwON E: AREA 7oe s ec - e ovuct.o=

June 5, 1981 37s-4oss Mr. James P. O'Reilly, Director

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'/7 U. S. Nuclear Regulatory Commission

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101 Marietta Street, Suite 3100 og 12 Atlanta, Georgia 30303 Og,,\\ o.s.tfjn c

Re: McGuire Nuclear Station Unit 1 Docket No. 50-369

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Lear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-80.

This repcrt concerns Train B of the RHR System incperable when the plant entered Mcde 5.

This incident was considered to be of no significance eith respect to the health and safety of the public.

Very truly yours, M

/-

j William O. Pa.-ker, Jr.

RWO:pw Attachment cc:

Director Mr. Bill Lavallee Office of Management & Drogram Analysis Nuclear Safety Analysis Center F.S. Nuclear Regulatory Commission P. O. Box 10412 Washington, D. C.

20555 Palo Alto, CA 94303 Ms. M. J. Graham Resident Inspector - NRC l

McGuire Nuclear Station l

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8108030300 810605 PDR ADOCK 05000369 5

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McGUIRE NUCLEAR STATION INCIDENT REPORT Report Number: 81-d0 Report Date:

June 4, 1981 Occurrence Date:

May 8, 1981 Facility: McGuire Unit 1, Cornelius, N. C.

Identification of Occurrence: Train B of the Residual Heat Removal (ND)

System was inoperable when the plant entered Mode 5.

Condition Prior to Occurrence:

Mode 5, Prior to initial criticality.

i Description of Occurrence: At 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> on May 8, 1981, the plant entered Mode 5 (reactor vessel head fully tensioned) without having both trains of the ND System operable.

This was reportable pursuant to Technical Specification 3.4.1.4.

Apparent Cause o5 Occurrence:

Operations personnel were not fully aware that the head tensioning was complete and did not take the steps necessary to prevent entering Mode 5 without having ND Train B operable.

In addition, there were no procedures which indicated what prerequisites must be met prior to entering Mode 5 from Mode 6.

I Analysis of Occurrence: At 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on May 5, 1981, valve 1NI-178 (ND pump B discharge to Safety Injection (NI) System) was red tagged closed in order to repair INI-81 (Cold leg accumulator C discharge check valve).

Thus, ND Train B was inoperable during this time.

The Shift Supervisor on duty on May 8 (0800-1600 hours) knew that ND Train B was inoperable but was not aware that the reactor vessel head tensioning uould be completed during his shift. Also, no Operations' procedures existed with sign off steps which indicated what prerequisites must i

be met prior to entering Mode 5 from Mode 6.

The head tensioning was completed at 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br /> on May 8 but Operations' personnel were not notified until 1350 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.13675e-4 months <br />.

Evidently, the personnel tensioning the head were not aware of the im-

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portance of notifying Operations when the head was tensioned.

In addition, Maintenance procedure, Reactor Vessel Head Removal and Replacement, did not cen-I tain steps to notify Operations' personnel while the head was being tensioned.

Valve 1NI-81 was repaired and 1N1-178 was operable (red tag removed and breaker energized) at 0550 hours0.00637 days <br />0.153 hours <br />9.093915e-4 weeks <br />2.09275e-4 months <br /> on May 9, 1981.

Safety Analysis

Since there was only new fuel in the core, no decay heat was present.

ND Train A waF available for other purposes if needed.

Thus, the i

health and safety of the public were not affected.

If the reactor had been at power and a mode change was required, Operating Procedure, Controlling Procedure for Unit stortur, outlines the steps necessary to take the plant from a cold shutdown (Mode 5) to 15% full power (Mode 1).

ND Train A could also be used if needed to help remove decay heat.

[

4 Report Number 81-80 Page 2

Corrective Action

An operating procedure will be written to verify that pre-requisites are met before entering Mode 5 from Mode 6.

This procedure will reference various Mode 5 periodic tests and Operations' logs.

The Maintenance Procedure will be changed to include tin above operating procesire t

as a prerequisite sign off step before the head is tensioned.

In addition, sign off steps to notify Operations' personnel during various stages of head tension-ing will also be included.

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