Audit of Small Break LOCA Guidelines (Generic Letter 79-68)
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.
8001070
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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
.
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
.
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
.
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
Page Last Reviewed/Updated Tuesday, March 09, 2021