05000219/LER-1981-049, Forwards LER 81-049/03L-0.Detailed Event Analysis Encl

Forwards LER 81-049/03L-0.Detailed Event Analysis Encl

ML20032E916
Person / Time
Site:	Oyster Creek
Issue date:	11/11/1981
From:	Carroll J JERSEY CENTRAL POWER & LIGHT CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20032E917	List: 05000219/LER-1981-049, Forwards LER 81-049/03L-0.Detailed Event Analysis Encl 05000219/LER-1981-049-03, /03L-0:on 811012,containment Spray Sys High Drywell Pressure Indicating Switches IP15A & IP15C Found to Trip at Values Greater than Tech Specs.Caused by Instrument Repeatability.Switches Reset & Setpoints Being Examined
References
NUDOCS 8111230497
Download: ML20032E916 (3)

LER-1981-049, Forwards LER 81-049/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2191981049R00 - NRC Website

text

.

CYSTER CREEK X

NUCLEAR GENERATING STATION

- cp mmraml

'*; ~.,(T'

^'

(009) t393-1951 P O f4CX 386

• FORKED RIVER = NEW JERSEY

• 08731 Novmber 11, 1981

/

S%

- e Mr. Ronald Haynes, Director y

Office of Inspection and Enforement

.h (fb'T l!w I "i j)

Region I N

i 6

~~I United States Nuclear Regulatory Ccxanission g "Il0V2 01981" 3l 631 Park Avenue

'6 A E I E M " " 4s/

King of Prussia, Pennsylvania 19406 s

Dear Mr. Haynes:

e s cn SUBJECr: Oyster Creek Nuclear Generating Station Docket No. 50-219 Licensee Event Report Reportable Occurrence No. 50-219/81-49/3L This letter ferwards three copies of a Licensee Event Report to report Reportable Occurrence No. 50-21s/81-49/3L in cmpliance with paragraph 6.9.2.b.1 of the Technical 3preiiications.

Very truly yours,

$!Y v

(

. T. Carroll, Jr.

[

Acting Director /

Creek JIC:dh Enclosures cc: Director (40 copies)

Office of Ir.ption end En&rcenent United States Nvlear Regulacory Ccmnission

}

Washington, D.C.

20555 Director (3)

Office of Management Information and Program Control United States Nucl. ear Pegulatory Ccmnissioa Washington, D. ". 26555 NRC Resident Inspwr (1)

Oyster Creek Nuclear GeneratinI Stati n

Forked River, N. J.

Ohd[jf9 tg

(

OYbTER CREEK NUCLEAR GENERATING STATICN Forked River, Nea Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/81-49/3L Report Date Novenber 11, 1981 Occurrence Date October 12, 1981 Identification of Occurrerm During surveillance testing the Containment Spray High Drywell Pressure Indicating Switches IP-15A and IP-15C tripped at values greater than those given in the Technical Specifications, table 3.1.1, iten E.1.

This event is considered to be a reportable occurrence as defined in the Technical Specifications, paragraph 6.9.2.b.1.

Conditions Frior to Occurrence The plant was in the refuel node with reactor tanperature less than 212 F and the reactor vented.

Desc @ ion of Occurrence eming perforraunce of the " Containment Spray Systen Autcmatic Actuation Test" (Surveillance Procedure 607.3.002), the IP-15A and 2-15C trip points were found to exceed the Technical Specifications desired setpoint. Testing of the four sensors yielded the following data:

Switch Designation Des!Ied Setpoint As Found (psig)

As Left (psig)

IP-15A

<2.0 psig 2.08 1.93 IP-15B

<2.0 psig 1.96 1.96 IP-lT 52.0psig 2.08 1.95 IP-lSD

<2.0 psig 2.0 2.0 Apparent Cause of Occurrence The crwse of the occurrence was instrument repeatability. The switch IP-15A was originally set at 1.93 and IP-15C at 1.92 psig, they both tripped at 2.08 psig.

She range for repeatability is 2-3% of full range, which in the case of the IP-15 switches is 0.2-0.3 psig. The differences of.15 psig for IP-15A and.16 psig for IP-15C between the setpoints and tne actwd trip points clearly falls within the range of instrument repeatability.

Reportable Occurrence Page 2 Report No. 50-219/81-49/3L Analysis of Occurrence

'Ihe Contaiment Spray Systs consists of two independent cooling loops, each of which is capable of removing heat frm the primary contaiment in the event of a loss of coolant accident. Wie Contamnent Spray System will be initiated upon receipt of both a tiigh drywell pressure signal and a reactor low-low water level signal.

Although switches IP-15A and IP-15C would have tripped at a slightly higher pressure than the desired setpoint, thsir actuation only would have been delayed by a fraction of a second. Also, the reactor law-law level setpoint is not reached until alnest 4 seconds later after the setpoint for high drywell pressure is reached. Due to this and the fact that switches IP-15B and IP-15D for the redundant instrument channel would have actuated at the required setpoints, the safety significance of the event is wnsidered nunimal.

Corrective Action

Pressure switches IP-15A and IP-15C were reset to trip within the Technical Specifications limit of 2.0 psig (as shwn in the "As Inft" values in the Description of Occurrence). 'Ihe drift problem of these snap-action switches is being investigated, along with possible setpoint changes to account for instr m ent repeatability.

Failure Data (same for both switches)

Manufacturer:

ITT Barton fedel:

1. 288A pressure indication switch F.rge:

0-10 psig 1

4