Bulletin 79-14: Supplement, Seismic Analysis for As-Built Safety-Related Piping Systems
SSINS: 6820
Accession No:
7968080360
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
August 15, 1979
Supplement IE Bulletin No. 79-14
SEISMIC ANALYSIS FOR AS-BUILT SAFETY-RELATED PIPING SYSTEMS
Description of Circumstances
IE Bulletin No. 79-14 was issued on July 2, 1979 and revised on July 18,
1979. The bulletin requested licensees to take certain actions to verify
that seismic analyses are applicable to as-built plants. This supplement to
the bulletin provides additional guidance and definition of Action Items 2,
3, and 4.
To comply with the requests, in IE Bulletin 79-14, it will be necessary for
licensees to do the following:
2. Inspect Part of the Accessible Piping
For each system selected by the licensee in accordance with Item 2 of
the Bulletin, the licensee is expected to verify by physical
inspection, to the extent practicable, that the inspection elements
meet the acceptance criteria. In performing these inspections, the
licensee is expected to use measuring techniques of sufficient accuracy
to demonstrate that acceptance criteria are met. Where inspection
elements important to the seismic analysis cannot be viewed because of
thermal insulation or location of the piping, the licensee is expected
to remove thermal insulation or provide access. Where physical
inspection is not practicable, e.g., for valve weights and materials of
construction, the licensee is expected to verify conformance by
inspection of quality assurance records. If a nonconformance is found,
the licensee is expected in accordance with Item 4 of the Bulletin to
perform an evaluation of the significance of the nonconformance as
rapidly as possible to determine whether or not the operability of the
system might be jeopardized during a safe shutdown earthquake as
defined in the Regulations. This evaluation is expected to be done in
two phases involving an initial engineering judgement (within 2 days),
followed by an analytical engineering evaluation (within 30 days).
Where either phase of the evaluation shows that system probability is
in jeopardy, the licensee is expected to meet the applicable technical
specification action statement and complete the inspections required by
Item 2 and 3 of the Bulletin as soon as possible. The licensee must
report the results of these inspections in accordance with the
requirements for content and schedule as given in Item 2 and 3 of the
Bulletin.
3. Inspect Remaining Piping
The licensee is expected to inspect, as in Item 2 above, the remaining
safety-related piping systems which were seismically analyzed and to
report the results in accordance with the requirements for content and
schedule as given in Item 3 of the Bulletin.
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Supplement IE Bulletin No. 79 Page 2 of 2
August 15, 1979
4A. Evaluate Noncomformances
With regard to Item 3A for the Bulletin, the license is expected to
include in the initial engineering judgement his justification for
continued reactor operation. For the analytical engineering
evaluation, the licensee is expected to perform the evaluation by using
the same analytical technique used in the seismic analysis or by an
alternate, less complex technique provided that the licensee can show
that it is conservative.
If either part of the evaluation shows that the system may not perform
its intended function during a design basis earthquake, the licensee
must promptly comply with applicable action statements and reporting
requirements in the Technical Specifications.
4B. Submit Nonconformance Evaluations
The licensee is expected to submit evaluations of all nonconformances
and, where the licensee concludes that the seismic analysis may not be
conservative, submit schedules for reanalysis in accordance with Item
4B of the Bulletin or correct the noncomformances.
4C. Correct Nonconformances
If the licensee elects to correct nonconformances, the licensee is
expected to submit schedules and work descriptions in accordance with
Item 4C of the Bulletin.
4D. Improve Quality Assurance
If noncomformances are identified, the licensee is expected to evaluate
and improve quality assurance procedures to assure that future
modifications are handled efficiently. In accordance with Item 4D of
the Bulletin, the licensee is expected to revise design documents and
seismic analyses in a timely manner.
The schedule for the action and reporting requirements given in the Bulletin
as originally issued remains unchanged.
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