ML20148Q322

Responds to Re Constituents Alleged Core Exposure at Plant.Plant Experienced Fuel Problems in 1970s,fission Product Releases Resulted from Cladding Problems & Core Exposure Incident Has Not Occurred

ML20148Q322
Person / Time
Site:	Pilgrim
Issue date:	01/25/1988
From:	Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
To:	Studds G HOUSE OF REP.
Shared Package
ML20148Q327	List: ML20148Q322
References
NUDOCS 8802010033
Download: ML20148Q322 (6)

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.. s JAN 2 51988 The Honorable Gerry E. Studds United States House of Representatives Washington, D.C. 20515

Dear Congressman Studds:

This is 'n response to your letter dated November 23, 1987, concerning the Pilgrim Nuclear Power Station.3 The following information is provided on the "matter of an alleged "core exposur.e incident" (taken here to mean partial core uncovering), raised in the letter from your constituent which was enclosed with your letter. Our review concludes that, although there were some fuel problems in the 1970's, these were associated with fuel design and fabrication tech-nology and not due to any fuel uncovering during plant operation.

By early 1971, the Atomic Energy Comission was aware that as a result of fab-rication and quality centrol problems at one of the vendor's fuel facilities, the General Electric (GE) Company supplied fuel to several reactor facilities, including Pilgr'm, which contained fuel pellets with improper fuel enrichment.

All of the fuel supplied to Pilgrin was returned to the GE facility for rework between August and November 1971. During that time, 2452 fuel rods were re-placed. After the fuel was returned to Pilgrim, additional problems were iden-tified which required that fourteen fuel rods from each of twelve fuel bundles be replaced. This work was done onsite and all prior to the initial loading of fuel into the Pilgrim reactor. Inspectors from the Atomic Energy Comissien followed the fuel enrichment problems, including witnessing portions of the onsite fuel rod replacement, to ensure the issue was resolved prior to the Boston Edison Conpany (BECo) loading the fuel into the reactor between June 9-15, 1972.

The initial criticality at Pilgrin occurred on June 16, 1972. Following start-up testing, the facility was placed in commercial operation in December 1972.

The facility then operated until its first refueling outage which occurred from December 28, 1973 through July 24, 1974. During this outage, 6ECo began re-lacing the original type of fuel bundles with those of a newer design. Twenty p(cut of 580) fuel bundles were replaced with newer type fuel bundles.

During late 1974, BEco noted a rise in the release from the fuel of airborne iodine and particulate fission products at Pilgrim. Reactor power level had to be reduced to maintain the gaseous effluent levels within the NRC License and Technical Specification requirements. Thn increase in gaseous effluents was subsequently detemined to be due to cracks in the fuel cladding. These cracks were caused by hydriding, a recognized corrosion mechanism, and fuel pellet-clad interaction which allowed fission products to enter the reactor coolant system. Other facilities experienced similar "leaking fuel" problems with the older type fuel. It was intended that the newer type fuel bundle would resolve such fuel leakage problems.

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The Honorabl'e Gerry E. Studds As noted above, the reactor power level had to be reduced to maintain gaseous effluents within regulatory liW.ts. Increased AEC/NRC inspection effort was spent to ensure the facility cperated within these limits. This included.

several independent measurement inspections. In addition, refueling activities were observed during the 1974, 1976 and 1977 refueling outages. BEco completed

- the replacement of the older type fuel during the 1977 outage which resolved the problems.

Based on our onsite reviews conducted at the time and our recent review of records, including inspection reports, we conclude that the fission product releases at Pilgrim resulted from the cladding problems discussed above and that a "core exposure incident" has not occurred.

We remain willing to receive further information, or talk directly to the interested constituent in order to more fully appreciate his concern if you deem it appropriate.

I trust this letter has been responsive to your request.

Sincerely, (signea) T. A. Rehnt

'ictor Stello, Jr Executive Director for Operations

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The Honorable Gerr'y E. Studds' DISTRIBUTION:

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PRADBURNE FOR SIGNATURE OF: ** GRFEN ** SFCY NO: 1391 EXECUTIVF DIRECTOR DESC: POUTING:

ENCLOSES l.ETTER FROM CONSTITUENT RE POSSIBLE MURLEY -

INCIDENT A*. PILCPIM MURRAY-DATE:-12/22/87 ASSIGNED TO: -RI CONTACT: RUSSELL

! SPECIAL INSTRUCTIONS OR REM. ARKS:

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OFFICE OF THE SECRETARY CORRESPONDENCE CONTROL TICKET PAPER NUMBER: CRC-87-1391 LOGGING DATE: Dec 4 87

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AUTHOR: G.E. Studds AFFILIATION: U.S. HOUSE OF REPRESENTATIVES LETTER-DATE: Nov 23 67 FILE CODE: ID&R-5 Pilgrim

SUBJECT:

Questions about a possible incident at the Pilgrim plant ACTION: Direct Reply DISTRIBUTION: OCA to Ack, Docket SPECIAL HANDLING: None NOTES.

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-AFFILIATION:' U.S. HOUSE OF REPRESENTATIVES LETTER DATE: Nov 23 87 FILE CODE: ID&R-5 Pilgrim

SUBJECT:

Questions about a possible incident at the Pilgrim plant ACTION: Direct Reply DISTRIBUTION: OCA to Ack, Docket SPECIAL HANDLING: None NOTES:

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