PY-CEI-NRR-1303, Part 21 Rept Re Finding That Nitrile Rather than Ethylene Propylene Diene Monomer (Epdm) Used as Seal Matl in Several E-sys Hydraulic Snubbers.Proper Seal Matl (Epdm) Used to Rebuild Snubbers & Leaking Valves Repaired

Part 21 Rept Re Finding That Nitrile Rather than Ethylene Propylene Diene Monomer (Epdm) Used as Seal Matl in Several E-sys Hydraulic Snubbers.Proper Seal Matl (Epdm) Used to Rebuild Snubbers & Leaking Valves Repaired

ML20067A939
Person / Time
Site:	Perry
Issue date:	02/04/1991
From:	Lyster M CENTERIOR ENERGY
To:	Office of Nuclear Reactor Regulation
References
REF-PT21-91 PY-CEI-NRR-1303, NUDOCS 9102080049
Download: ML20067A939 (3)

Text

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Y PERRY NUCLEAR POWER PLANT Mall Address:

RO. BOX W Mad O. @M 10 CENTER ROAD PERRY, OHIO 44081 PERRY, OHIO 44081 VICE PRESIDENT NUCLEAR (216) 269 3737 l 1

1 February 4, 1991 PY-CE1/NRR-1303 L 1

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i Director, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C. 20555 Perry Nucicar Power Plant Docket No. 50-440 10 CFR Part 21 Notification -

E-Systems Hydraulic Snubbers Gentlemen:

Pursuant to the requirementa of 10CFR21.21(b)(2), the NRC'was notified on February 1,1991 of a 10CFR21 reportable condition identified at the Perry Nuclear Power Plant (PNPP). The condition involves the finding that Nitrile, ,

rather than Ethylene Propylene Diene Monomer (EPDM), was used as a seal material

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in several E-Systems hydraulic anubbers installed in the PNPP, Unit 1.

Enclosed are three copies of the written report which is being submi?ted 'n-accordance with 10CFR21.21(b)(2) and (b)(3).

• If you have any questions, please feel free to call.- I Sincerely, }

Mb ,

Michael D. Lyster MDLICSanjc Attachment c e s. A. B. Davis, Region III USNRC Project Manager USNRC Resident Office USNRC Document Control Desk opeeng comten h one4ana Emetne mum **no

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PY-CEI/NRR-1303L Page 2 of 2 vi. The Number and__ Location of Basic Components '

PNPP was furnish (6 with a total of 21 E-Systems snubbers under Specifi ation SP-527. All 21 of these snubbers are located in the drywcil. There are fifteen 50 KIP E-Systems snubbers (PN-152005) and six 70 KIP-snubbers (PN-152007). Of these 21, three 50 KIP snubbers are located on the Residual Heat Removal (RHR) system, two 50 KIP snubbers are located on the Low Pressure i Core Spray (LPCS) system and two 50 KIP :nubbars are located on the High Pressure Core Spray (HPCS) system. Eight 50 KIP and six i

70 KIP snubbers are located on the reedwater system.  ;

vii. corrective Actions During the investigation, it was determined that the two weeping snubbers were located in the general area of two reedwater system valves which had been leaking steam during the first operating cycle. These leaking valves were repaired during RFO-1. All E-Systems hydraulic snubbers in this local hot spot area were rebuilt using the proper seal material (EPDM) during=RTO-2.

An engineering evaluation has been performet on the substitute '

Nitrile seals that were exposed to PNPP's worst case ambient environment (upper drywell). The compression set on these  ;

Nitrile seals-was found to be approximately 60%. The Bayonet seals are a static type of seal and will perform their intended j

function with a compression set of up to approximately 90%. A field walkdown was performed of E-Systems hydraulic snubbers that were physically accessible at the time of this evaluation during.

RFO-2. All fifteen 50 KIP E-Systems snubbers and two of the 70 ,

KIP E-Systems snubbers were visually inspected. With the exception of the two snubbers previously identified, no other snubbers within this sample were found to hsve any signs-of weepage. Based upon the engineering evaluation of the Nitrile snubber seals and based upon their location (Bayonet area), it has been determined that he snubbers will perform their intended function for a minimum of at loset one more operating cycle.

A Nonconformance Report has been issued against E-Systems snubbers from several different procurement specifications'with .

varying manufacturing dates. Fifty-three snubbers are conservatively contained within this suspect population. Nine of these 53 were rebuilt using EPDM seals _during RFO-2. The remainder will either be rebuilt using EPDM seals, or.Will be totally removed from the plant through snubber reduction efforts prior.to reactor startup following RFO-3.

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• Attachment l

PY-CEI/NRR-2303L Page 1 of 2

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10CFR21 Report on E-Systems Hydraulic Snubbers

i. Name of Person Notifying the Commission E. Riley - Director, Perry Nuclear Assurance Department

11. Identification of Facility and Basic-Component Perry Nuclear Power Plant, Unit I Snubbers Manufactured by E-Systems E-Systems Part Numbers - 152005 (50 KIP) 152007 (70 KIP) 111. Identification of Firm Supplying the Basic component The snubbers were manufactured by: E-Systems, Montek Division, Salt Lake City, Utah and procured through Specification SP-527 issued to Pullman Power Products, iv. Nature of Defect and Safety Hazard Created Six E-Systems hydraulic snubbers installed on Class 1 portions of the feedwr.ter system were-found to have Bayonet seals composed of Nitrile instead of Ethylene Propylene Diene Monomer (EPDM) as required by vendor design documents. All six snubbers had a manufacturing date of April 1982, and all six were procured through l

Specification SP-527. One 50 KIP and one 70 KIP E-Systems snubber were found with signs of minor hydraulic fluid ~1eakage (weepage),

which subsequently led to the identification of the substitute seal material. A chemical evaluation was performed on the seal material 1 and it was identified as being Nitrile rather than EPri. An engineering evaluation was then performed on the Nitri?e seal material with the conclusion that any remaining snubbers containing Nitrile will perform their safety function through at least the next operating cycle, and therefore no safety hazard exists through the same period.

j v. Date Information was obtained January 30, 1990 l

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