ML20151L421

Discusses Compliance Evaluation Rept Re Application ,revised 970214 & 0616 for Autoclave Manual Isolation Sys

ML20151L421
Person / Time
Site:	07007001
Issue date:	07/16/1997
From:	NRC
To:	NRC
References
NUDOCS 9708060328
Download: ML20151L421 (3)

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UNITED STATES J NUCLEAR REGULATORY COMMISSION E

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SUBJECT:

COMPLIANCE EVALUATION REPORT: APPLICATION DATED OCTOBER 31,1996, REVISED FEBRUARY 14, AND JUNE 16, 1997, AUTOCLAVE MANUAL ISOLATION SYSTEM BACKGROUND By letter dated October 31,1996, the United States Enrichment Corporation (USEC) requested an amendment to the proposed certificate of complL we for the Paducah i Gaseous Diffusion Plant (PGDP). The request was based on th:

• posed certificate because the final certificate was not issued until Novem12er 26,1996. The sequest is to incorporate a new Technical Safety Requirement (TSR) 2.4.4.13 associated with the Autoclave Manual Isolation System and to revise the appropriate pages in the Safety Analysis Report (SAR). By letters dated January 15,1997, the staff requested additional information. Staff review of the Feb'ruary 14,199L USEC response, generated a second i request for additional information dated May 1,1997. USEC responded to the second request by letters dated May 16, and June 16,1997. This amendment request was submitted in accordance with Compliance Plan issue 3.

DISCUSSION in Compliance Plan issue 3, Action 1, USEC committed to install manual push buttons l which would be used to place the feed facility autoclaves into containment upon I confirmation of a uranium hexafluoride release. The push buttons were to be installed at l the Operations Monitoring Room (OMR) door and at the crane bay exit near the local l

cylinder yard and would be activated by the operator as the operator left the area upon i seeing a release. A third push button was to be installed in the Area Control Room (ACR).

The Compliance Plan required USEC to submit a TSR for the autoclave manual isolation system, i The autoclave manual isolation system provides a mechanism to remotely isolate all the l autoclaves in the feed facility in the event of a uranium hexafluoride release from piping outside the autoclave. The manual isolation device allows the simultaneous isolation of all autoclaves in the affected facility. Previously this was conducted individually for each autoclave by simulating a high-high conductivity signal which would place the autoclave 1

into containment mode. Placing the autoclave into containment eliminates the source of uranium hexafluoride available for release thus terminating the release.

The system, as installed, consists of two local (within the feed facilities) actuation devices (pull buttons) located in the OMR and at the cylinder yard crane bay exit, and one remotely l '

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i. 2 i located actuation device in the associated cascade building ACR. The cylinder yard crane bay exit is the most likely point of egress frorn the autoclave area in the event of a release. ,

(Note that USEC installed pull buttons versus the push buttons designated in the  !

compliance plan to reduce the potential for inadvertent actuation; the staff finds the pull j buttons to be an acceptable alternative). The remainder of the system consists of the programmable logic controller, the autoclave isolation valves, and the interconnections j between the components. The actuation device sends a signal to the programmable logic i controller which then sends a signal to close the isolation valves on the autoclaves, i TSR 2.2.4.13 requires the autoclave manual isolation system actuation devices to be operable while the autoclave is in the closed mode or in a heating, feeding, or heeling operational mode, if only one local device is available, an operator is appropriately ,

stationed, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, to activt 'e the operable actuation device, if both local devices j are inoperable, one device must be restored to an operable status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. If I operability is not restored within the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> window, actions must be immediately taken to l close containment valves or place the autoclave in an open or out of service mode, or i operations can continue by establishing radio communication with the ACR to ensure  !

immediate capability to actuate the system from the ACR in the event of a release and l restoring operability within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Since at least one of the actuation devices is i available during operations and there is a UF. release detection system in the area, the 4  ;

hour window is acceptable. The surveillance required by this TSR is an annual functional  ;

test of the system actuation devices. The actuation device and the signal sent from the l actuation device to the programmable logic controller are tested annually. The l programmable logic controller, valve closure signal, and the isolation valves are tested i quarterly as part of the surveillance for the autoclave high pressure isolation system. An I annual surveillance is acceptable for testing the system under this TSR.

USEC also submitted changes to the SAR to remove the Compliance Plan references and to make the system a Q system under the quality assurance program. As part of the original amendment package, USEC submitted changes to the Compliance Plan to reflect pull button actuation devices versus the push button type specified in the Compliance Plan.

The staff has determined a revision to the Compliance Plan is not necessary and therefore will not include the Compliance Plan changes in the amendment to the Certificate.

ENVIRONMENTAL REVIEW lssuance of an amendment to Certificate of Compliance GDP-1 to include a new TSR that addresses the autoclave manual isolation system is subject to the categorical exclusion q provided in 10 CFR 51.22(c)(19). Therefore, neither an environmental assessment nor an i environmental impact statement is required for the proposed action. i l

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I CONCLUSION I i

1 The proposed TSR 2.4.4.13 on the Autoclave Manual isolation System provides a means  ;

j to remotely isolate all facility autoclaves in the event of a uranium hexafluoride release '

from the piping outside the autoclave. This system is considered an enhancement in l support of the mitigation of a release. The staff recommends that the new TSR and the  !

l SAR changes be approved. Issuance of the certificate amendment will close Action 1 of l

Compliance Plan issue 3.

The Region !!! Inspection staff have no objection to this proposed action. l l l l

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Princioal Contributor l Merri Horn i

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