ML20058N711

Responds to NRC Bulletin 91-001,suppl 1, Reporting Loss of Criticality Safety Controls

ML20058N711
Person / Time
Site:	07000734
Issue date:	10/13/1993
From:	Asmussen K GENERAL ATOMICS (FORMERLY GA TECHNOLOGIES, INC./GENER
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-91-001, IEB-91-1, NUDOCS 9310200234
Download: ML20058N711 (5)

Text

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CENERAL4TDREN"E October 13,1993

'l 696-2135 q

VIA OVERNIGHT EXPRESS SERVICE:

ATTN Document Control Desk j

U. S. Nuclear Regulatory Commission l

Washington, DC 20555

Subject:

Docket No.70-734; License No. SNM-696; Response to NRC Bulletin 91-01,.

Supplement 1

References:

1)

Asmussen. Uith E., Letter No. 696-1867 to U. S. NRC, " Response to NRC Bulletin 91'.

01," dateo February 27,1992 2)

Hickey, John W. N., Letter to General Atomics, ATTN: Dr. Keith E. Asmussen, dated April 10,1992 3)

Asmussen, Keith E., letter No. 696-1908 to U. 5. NRC, " Revised Response to..NRC Bulletin 91-01," dated May 15,1992 4)

"NRC Bulletin 91-01, Supplement 1: Reporting loss of Criticality Safety Controls" OMB ~

No. 3150-0009, July 27,1993 Gentlemen:

l General Atomics (GA) responded to NRC Bulletin 91-01 by letter (with Attachments l

A through D) dated February 27,1992 (Ref.1). By letter dated April 10,1992, Mr. Hickey (NRC) requested additional information to clarify several issues (Ref. 2). GA submitted the' revised response in a letter dated May 15,1993 (Ref. 3). In Supplement 1 of NRC Bulletin 91-01, NRC provided all licensees with a clearer reporting criteria and requested that certain actions be taken (Ref. 4). Accordingly, GA hur.by submits its response to Supplement 1.,

which it trusts you will find appropriate and responsive to the issues identified.

Attachment D, provided in Ref. 3, describes the criticality safety event reporting

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criteria GA intends to use in determining which events or situations could constitute, or lead

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to significant degradation of the effectiveness of criticality controls and thereby require reporting to NRC. Attachment D has been revised to make it responsive to Supplement 1-1 of Bulletin 91-01.

The criteria contained herein will be incorporated into GA's Nuclear Safety. Guide within 30 days of NRC's concurrence with this response, and these criteria will be factored into any future nuclear safety training.

GA's Radiological Contingency Plan provides for the classification and ' assessment of radiological contingencies. A significant degradation of a criticality control could result in the Plan's implementing procedures being activated. This would occur, for example, if events indicate a potential significant degradation of the level of safety of the plant. Further,

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l U. S. Nuclear Regulatory Commission 696-2135 October 13,1993 Page 2 t

the plan does address the procedure to follow in the event of a nuclear criticality. The guidance and requirements of NRC Bulletin 91-01, Supplement 1 will be factored into the next review and resulting revision to GA's Radiological Contingency Plan.

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If you should have any further questions on this matter, please do not hesitate to contact rne at (619) 455-2823.

Very truly yours, t

e Keith E. Asmussen, Director Licensing, Safety and Nuclear Compliance 1

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Attachment D - Rev.1 cc:

Mr. Bobby Faulkenberry, NRC Regional Administrator, Region V Mr. Robert Wilson, NRC Headquarters ALL-PURPOSE ACKNOWLEDOMENT

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J General Atomics 696-2135 Attachment D - Rev 1 Oct.13,1993 Page 1 of 3 l

CRITICALITY SAIf TY EVENT REPORTING CRITERIA and APPROPRIATE RESPONSE ACTIONS The criticality safety event reporting criteria described herein was developed by General Atomics as guidance in determining which events or situations could constitute, or lead to, significant degradation of the effectiveness of criticality controls and thereby require reporting to the U.S. Nuclear Regulatory Commission (NRC) when quantity of SNM involved l

is greater than a safe mass, or when moderation is used as the primary criticality control.

ihese reporting criteria will be incorporated into General Atomics' Nuclear Safety Guide.

Notifications to NRC made pursuant to these criteria do not require follow-up written reports to the NRC.

DEFINITIONS 1.

Parameter: a characteristic of a system which must be controlled for purposes of criticality safety, e.g., mass, geometry, concentration and moderation, 2.

Control; that which prevents a criticality accident by maintaining a parameter within specified limits, e.g., density meter, weighing scales, spacing, moisture meter, and volume measurement.

3.

Double Continnency Principle (Ref: ANSI /ANS-8.1-1983 Rev. 88): process designs should, in general, incorporate sufficient factors of safety to require at least two unlikely, independent, and concurrent changes in process conditions before a criticality accident is possible.

4.

Safe Mass: forty-five (45) percent of the minimum critical mass of special nuclear l

material for a given enrichment.

5.

Re-establish: establish within four (4) hours after the identification of the event the conditions to assure that the double contingency principle and the pre-established licensed conditions for that system exist.

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1 General Atomics 696-2135 Attachment D - Rev 1 Oct.13,1993 Page 2 of 3

-l CONDITION ACTION Notification of Nuclear Safety and of 1.

An event that may have caused or threatens to cause significant degra-Licensing, Safety and Nuclear Compli-dation or loss of all the controlled ance parameters and thereby caused or Notify NRC as soon as possible within

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threatens to cause a criticality excursion.

four (4) hours of discovery Activate Radiological Contingency Plan Determine corrective actions, including steps to prevent recurrence, and docu-ment occurrence Implement corrective actions Notification of Nuclear Safety and of

2. An event that results in the violation of the double contingency principle Licensing, Safety and Nuclear Compli-and where the double contingency ance principle cannot be re-established within four (4) hours after the initial Determine whether to activate Radio-observation of the event.

logical Contingency Plan Notify NRC as soon as possible within four (4) hours of the initial observation Determine corrective actions, including steps to prevent recurrence, and docu-ment occurrence implement corrective actions e

3. Loss or failure of a controlled para-Notification of Nuclear Safety and of meter previously identified by the Licensing, Safety and Nuclear Compli-NRC or Nuclear Safety as requiring ance immediate reporting upon loss or failure and where the double contin-Notify NRC as soon as possible within gency principle cannot be reestab-four (4) hours of the initial observation lished within four (4) hours after the initial observation of the event.

Determine corrective actions, including steps to prevent recurrence, and docu-ment occurrence e

implement corrective actions

General Atomics 696-2135 Attachment D - Rev 1 Oct.13,1993 Page 3 of 3

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t CONDITION ACTION Notification of Nuclear Safety and of

4. Occurrence of an unusual event or condition believed to involve degra-Licensing, Safety and Nuclear Compli-dation of criticality controls, but for ance which the safety significance or cor-rective actions to re-establish the Determine whether to activate Radio-double contingency principle cannot logical Contingency Plan be readily determined Notify NRC as soon as possible within four (4) hours of the initial observation Determine corrective actions, including steps to prevent recurrence, and docu-ment occurrence e

implement corrective actions Notification of Nuclear Safety and of

5. Discovery that a criticality safety analysis / evaluation was seriously Licensing, Safety and Nuclear Compli-deficient with the result being a ance necessary controlled parameter (s)

Notify NRC as soon as possible within limit not being appropriately set y

four (4) hours of discovery Determine corrective actions, including steps to prevent recurrence, and docu-ment occurrence implement corrective actions e

Notification of Nuclear Safety and of

6. An event that results in a violation of a

the double contingency principle but Licensing, Safety and Nuclea Compli-for which control is re-established ance within four (4) hours Notify NRC as soon as possible within twenty-four (24) hours of discovery Determine corrective actions, including steps to prevent recurrence, and docu-ment occurrence Implement corrective actions

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