NRC Generic Letter 79-68, Audit of Small Break LOCA Guidelines

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GL79068

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555

December 17, 1979

TO LICENSEES OF ALL OPERATING NUCLEAR POWER PLANTS

Gentlemen:

SUBJECT: AUDIT OF SMALL BREAK LOCA GUIDELINES

The Bulletins & Orders Task Force has now approved the small break loss of coolant accident guidelines for essentially all operating plants. As discussed in our letter of September 13, 1979 to the licensees of all operating nuclear power plants, licensees are to prepare emergency procedures and complete the associated training of operators by December 31, 1979.

As part of this program, members of the Bulletins and Orders Task Force plan to audit the program of selected utilities to assure that the implementation of the respective programs for incorporating the revised procedures are acceptable. The plants which the Bulletins and Orders Task Force will visit and the schedule are as follows:

Westinghouse Plants

Salem 1 December 10, 1979 North Anna 1 December 19, 1979 Haddam Neck December 20, 1979

Combustion Engineering Plants

Millstone 2 December 19, 1979

General Electric Plants

Nine Mile Point 1 December 10, 1979 Fitzpatrick December 11, 1979 Dresden 2 & 3 December 12, 1979

The programs for those plants which are not audited by the Bulletins and Orders Task Force will be audited by representatives of the Office of Inspection and Enforcement.

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To help assure that these audits are effective and efficient for both the licensees and the staff we have developed the enclosed audit plan. This audit plan will be used by both the Bulletins and Orders Task Force and the Office of Inspection and Enforcement in conducting the audits.

If you require any clarification of the matters discussed herein please contact the assigned Operating Reactors Project Manager for your plant.

Sincerely,

Darrell Eisenhut, Acting Director Division of Operating Reactors

Enclosure:

As stated

cc: See attached lists

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Enclosure

AUDIT OF SMALL BREAK LOCA PROCEDURES

1. Comparison to Guidelines

The NRC staff will coffipare the small break procedure to the guidelines approved for the plant type. In addition to checking against the specific line items (actions and precautions) in the guideline, the NRC staff will consider the clarity of the procedure, in terms of individual actions and precautions, and flow of the procedure with respect to timely initiation of all operator actions.

The licensee should have personnel familiar with the development of the small break LOCA procedure available to answer NRC staff questions about omissions and ambiguities in the procedure. The utility should explain the process by which the approved guidelines were converted into operating procedures includinq, the results of internal review, problem areas, and plant specific information required in the procedure.

2. Training

The NRC staff will review the training the reactor operators received in the small break LOCA procedure. We expect this training to include formal classroom study and a walk thru of the procedure with the shift supervisor or training coordinator.

The licensee should have the training coordinator available to discuss the training with the NRC staff.

3. Operator Feedback

A member of the Operator Licensing Branch or an IE Inspector will audit several operators to determine the adequacy of the procedure from a

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functional standpoint and the effectiveness of the training program. The audit, which is oral, will cover understanding of small break LOCA, differ-

erntiation between LOCAs and other depressurization events, familiarity with the smll break LOCA procedures, basis for the revised procedures, and whether the procedures can be effectively carried out.

The licensee should have several operators available, including senior operators who can be questioned by the staff.

4. Systems Considerations

The NRC staff will review system-related aspects of the procedure to assure that the operawr actions can be performed. These systems considerations will vary with plant type as noted in Table 1.

The licensee should have technical personnel and documentation available (including P&ID of ECCS) to respond to NRC staff questions on system considerations in the procedure.

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Westinghouse

a) Instrumentation - Certain instrumentation is used by the operator in the procedure to initiate actions such as HPI temination and switchover from injection to recirculation. The licensee should show that the instrumentation used as part of this procedure will provide adequate information for performing operator actions considering instrument uncertainty, environmental conditions at the time it is required, and power (with loss of offsite power and a single failure).

b) Reactor Coolant Pump Trip - The licensee should show that the primary system pressure at which he trips the reactor coolant pumps in his procedure is consistent with the prescription in the guideline's.

c) Manual Switchover - For those plants which rely on the operator to perfom a portion or all of the switchover from injection to recirculation, the licensee should show that this action can be performed before the RWST water level reaches an unacceptable level. A time sequence table should be available showing procedure steps, flow out of the RWST, volume of water reinaining in the RWST, and time required to perform each step as a function of time. Maximum ECCS and containment spray flow should be used to develop the sequence table.

d) HPI Protection After Switchover - For those plants that have HPI pumps with 1400-1500 psi shut off heads, the licensee should show how the prpcedures will preclude damage to those pumps after switchover to recirculation from the sump for break sizes that would result in deadheading the pumps after switchover. Under these conditions, the procedures should also provide instructions for maintaining adequate pressure level inventory

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after switchover.

e. Bulletin Items - The licensee should show how he has incorporated his responses to the I&E bulletins (issued in April 1979) in his procedure with respect to:

Containment Isolation PORV Indication Transfer of Fluids Out of Containment Hydrogen Gas

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Combustion Engineering

a) Instrumentation - Certain instrumentation is used by the operator in the procedure to initiate actions such as HPI termination and switchover from injection to recirculation. The licensee should show that the instrumentation used as part of this procedure will provlde adequate information for performing operator actions considering instrument uncertainty, environmental conditions at the time it is required, and power (with loss of offsite rower and a single failure).

b) HPI Protection After Switchover - For those plants that have HPI pumps with 1400-1500 psi shut off heads, the licensee should show how the procedures will preclude damage to those pumps after switchover to recirculation from the sump for break sizes that would result in deadheading the pumps after switchover. Under these conditions, the procedures should also provide instructions for maintaing adequate pressure level inventory after switchover.

c) Bulletin Items - The licensee should show how he has incorporated his responses to the I&E bulletins (issued in April 1979) in his procedure with respect to:

Containment Isolation PORV Indication Transfer of Fluids Out of Containment Hydrogen Gas

(OVER)

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General Electric

a) Instrumentation - Certain instrumentation is used by the operator in the procedure to initiate actions such as HPI termination and switchover from injection to recirculation. The licensee should show that the instrumentation used as part of this procedure will provide adequate information for performing operator actions considering instrument uncertainty, environmental conditions at the time it is required, and power (with loss of offsite power and a single failure).

b) Bulletin Items - This licensee should show how he has incorporated his responses to the I&E bulletins (issued in April 1979) in his procedure with respect to:

Containnment Isolation Transfer of Fluids Out of Containment Hydrogen Gas

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OPERATING LICENSE

Pressurized Water Reactors

50-003/247 50-029 50-206 50-213 50-244 50-250/251 50-255 50-260 50-261 50-266/301 50-269/270/287 50-272 50-280/281 50-282/306 50-285 50-286 50-289/320 50-295/304 50-302 50-305 50-309 50-312 50-313/368 50-315/316 50-317/318 50-321 50-334 50-335 50-336 50-338 50-344 50-346 50-348

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OPERATING LICENSE

Boiling Water Reactors

50-010/237/249

50-133

50-755

50-219

50-220

50-245

50-254/265

50-259/296

50-263

50-271

50-277/278

50-293

50-298

50-325/324

50-331

50-333

50-366

50-409