05000219/LER-1981-061, Forwards Updated LER 81-061/03X-1.Detailed Event Analysis Encl

Forwards Updated LER 81-061/03X-1.Detailed Event Analysis Encl

ML20053D116
Person / Time
Site:	Oyster Creek
Issue date:	05/25/1982
From:	Fiedler P GENERAL PUBLIC UTILITIES CORP.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20053D117	List: 05000219/LER-1981-061, Forwards Updated LER 81-061/03X-1.Detailed Event Analysis Encl
References
NUDOCS 8206040098
Download: ML20053D116 (5)

LER-1981-061, Forwards Updated LER 81-061/03X-1.Detailed Event Analysis Encl

Event date:
Report date:
2191981061R00 - NRC Website

text

~

GPU Nuclear g

f QQlgg7 P.O. Box 388 Forked River, New Jersey 08731 609-693-6000 Writer's Direct Dial Number:

May 25, 1982 Mr. Ronald C. Ilaynes, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 Dea r M r. Ilayne s :

Subject: Oyster Creek Nuclear Generating Station Docke t No. 50-219 Licensee Event Report Update Reportable Occurrence No. 50-219/81-61/03X-1 This letter forwards three copies of a Licensee Event Report Update to provide supplemental information regarding Reportable Occurrence No.

50-219/81-61/03X-1 in compliance with paragraphs 6.9.2.b.2 and 6.9.2.b.3 of the Technical Specifications.

Very truly yours.

A O

Peter B. Fiedler Vice President & Director Oyster Creek PBFrlse Enclosures cc:

Director (40 copies)

Of fice of Inspection and Enforcement U.S. Noclear Regulatory Commission Washington, D.C.

20555 Director (3)

Of fice of Management Information and Program Control U.S. Nuclear Regulatory Commission Washington, D.C.

20555 NRC Resident Inspector (1)

Oyster Creek Nuclear Generating Station Forked River, NJ 08731 8206040098 820525 PDR ADOCK 05000 s

a i

GPU Nuclear is a part of the General Pubhc Utihties System

• /

/

OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 6-Licensee Event Report Update j

Reportable Occurrence No. 50-219/81-61/03X-1 i

I Report Date f

May 25, 1982 r

Occurrence Date f-4 g

December 22 & 23, 1981

/j<

Identification of Occurrence Operation in a degraded mode permitted by a limiting condition for operation (Section 3.5. A 8) when nine (9) hydraulic anubbers were found to be inoperable during functional testing. These snubbers are located on the containment spray, core spray, shutdown cooling, and isolation condenser systems.

In addition, the accelerated surveillance of Technical Specification 4.5.Q.3, which is required for snubbers whose seal materials have not been demonstrated to be compatible with the operating environment, was not performed.

This event is considered to be a reportable occurrence as defined in the Technical S pe ci fica t ions, pa ragraph s 6.9. 2.b. 2 and 6.9.2.b. 3.

e t

/i Description of Occurrence t

During the period of November 23 through December 9, eleven (11) Bergen Pat.tersan hydraulic anubbers were found. deficient during visual inspections. These snubbers were replaced with operable spares within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in agiordance with Technical Specification requirements. ' The visual inspection dates are shown in the table

'i, below.

/

On December 21 s 22, 1981.,these eleven (11) snubbers were tested for operability and nine (9) of these snubbers weare detennined to be inoperable and tne results of

~

these tests follow:

7 SNUBBER SER AL VISUAL DRAG LOCK UP RELEASE LOCATION NINBER SYSTEM INSPEC.

LOAD VELOCITY RATE VEL.

COMMENTS 6

95/2 469853 Isolation 12/3 Pa ss( P) Fa il(F)

Fail ( F)

Inoperable Condenser A, l

l 75/7

. 4 87501 Isolation 11/ 30 j

P F

F boperable.

/

Condenser B

/

-- o

~

nf 75/2 469897 Core; Spray 11/30 <

P F

F Inoperable

}

r 8

I South j

1 51/12 F8 9977-6 Shutdown 11/I,0,

P F

F Inoperable

)

i Cooling I

1 I

f'

,l

. ~

f

{i lt s

a~ n -

Licensee Event Report Update Page 2 Report able Occurrence No. 5 0-219 /81-61/ 03X-1 SNUB BER SERIAL VISUAL D RAC LOCK UP RELEASE LOCATION NtN BER SYSTEM INSPEC.

LOAD VELOCITY RATE VEL.

COMMENTS 23/5 487489 Containment 11/23 P

F F

Inoperable Spray South 51/13 487528 Shutdown 11/ 23 P

F F

Inoperable Cooling 51/9 93501 Core Spray 11/30 P

F F

Inoperable North

- 19/18 469846 Core Spray 11/30 P

F F

Inoperable North

- 19/4 F9 3502 Containment 11/ 25 P

P F

Inoperable Spray North All the above snubbers were tested on our Bergen Patterson test machine which was calibrated on 12 /17/81.

"P" indicates snubber passed test,

"F" indicates a failure.

Apparent Cause of Occurrence All snubbers were identified as deficient during visual examinations. All affected snubbers exhibited a low oil level or evidence of oil leakage.

Upon disassembly of the nine snubbers, it was revealed that four snubbers contained molded polyure thane seals. The remaining five possessed ethylene propylene seal material.

Snubbers at locations 95/2, 75/2, 51/12, and -19/18 possessed the molded polyurethane seals. Af ter prolonged exposure to radioactivity and heat, molded polyurethane seals become brittle and eventually crack.

Snubber 75/2 had seals that were very brittle while -19/18 had seals that were already cracked.

Snubber 75/2 exhibited oil leaks and oil was found airbound in -19/18; -19/18 also indicated scored poppet valves.

Snubbers at locations 95/2 and 51/12 possessed molded polyurethane seals that were in fair to good condition.

Snubber 95/2 had a scored tension poppet valve which resulted in a poor lock up velocity in the tension test.

Snubber 51/12 of the Shutdown Cooling System exhibited a scored tension poppet valve as well as visual oil leaks.

Snubbers at locations 75/7, 23/5, 51/13, 51/9, and -19/4 contained the ethylene propylene seal material which retains its elastic and sealing properties in the presence of radioactivity and heat. All seals were found to be in fair to good condition with the exception of 23/5 and 75/7.

Snubber 75/7 seals were in poor condition with oil leaks evident, while 23/5 possessed a cracked piston seal and a scored shaf t.

Snubbers 51/13 and -19/4 contained seals in good condition with no apparent oil leaks.

Airbound oil and worn poppets were revealed in these snubbers af ter disassembly. Seals in 51/9 were in fair condition but the compression poppet was scored.

Licensee Event Report Update Page 3 Report able Occurrence No. 5 0-219/81-61/ 03X-1 Analysis of Occurrence Hydraulic snubbers are installed to limit piping movement during seismic events and during transient conditions. Another function is the ability of the piston to I

move freely during normal operation to compensate for thermal expansion or contraction. As a result of inoperable anubbers in the piping systems, the ability of these systems to perform their intended function during a seismic event may have been degraded.

Corrective Ac tion All nine inoperative snubbers were replaced with operable spares that were certified operable by Bergen Patterson.

There a re e ight y e ight (88) hydraulic anubbers in the Reactor Building outside the d rywel l. As of May 17, 1982, seventy-five (75) of these snubbera are new (1981 and 1980 models) and have been certified as to material and operability by Bergen Patterson or have been recently rebuilt at Oyster Creek and tested on the calibrated Bergen Pa tterson machine. The remaining thirteen (13) will be visually inspected during puwer operation on a monthly schedule until they are replaced with new or rebuilt snubbers.

All thirteen (13) will be replaced by September 198 2.

Snubbers with external piping (400,000 series) will be permanently removed from service (8 total). All " Integral Valve Manifold" type snubbers (F00,000-X series) will be removed, replaced with operable spares, rebuilt, tested and reinstalled as replacement units for external pipe models and as needed in the future.

The presence of molded polyurethane seal material in several of these snubbers can i

be at tributed to the following:

During the September 1973 shutdown of Oyster Creek, all snubbers within the drywell and most of the snubbers in the Reactor Building were rebuilt with seals made of molded polyurethane, viton, and ethylene propylene.

In December of 1973, General Electric Company reported that snubber seal tests indicated that ethylene l

propylene (EP) seal naterial was best suited for use in Bergen Patterson snubbers. A program to rebuild defective snubbers with EP seals was initiated.

l Deficient units were constantly being rebuilt with EP seals and put back into service.

Repaired and/or rebuilt replacement snubbers contained only EP seals, with the exception of the main shaft packing seal.

EP main shaft packing seals were not available for some of the snubber models that were in use at that time.

l l

l l

i

--_._____m._-

Licensee Event Report Update Page 4 Reportable Occurrence No. 5 0-219/Cl-61/03X-1 At this time, all Bergen Patterson seal repair kits contain all EP seals including the main shaf t seal. Molded polyurethane seals are no longer being used in the rebuilding of snubbers. Mechanics directly involved with snubber rebuilding and testing have completed a Bergen Patterson training program which was given in December 1981. The training program covered snubber rebuilding and testing, and operation of the Bergen Patterson functional testing machine.

At present, the majority of the snubbers in the reactor building have been rebuilt with EP seals.

All snubbers in the drywell have been replaced with mechanical models.

In all probability, the snubbers that were found to contain molded polyurethane seal materials had passed their functional testing since the program s ta rted. After a snubber passed the test, i t need not have been rebuilt before being put back into service.

Therefore, the seals were never replaced unless the support was found defective during functional testing.

Fa ilure Data Bergen Patterson Hydraulic Shock and Sway Arrestors All Type HSSA - 10 KIP All 6" Stroke All 2.5" Bore 4

4 s

_m--

y

,v-,..-.-g-m-m yr.%_

yy...-.,

..,.m_

m_._w

___-m._