Bulletin 79-01B: Supplement Information, Environmental Qualification of Class IE Equipment
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
February 29, 1980
IE Bulletin No. 79-01B
Supplement Information
ENVIRONMENTAL QUALIFICATION OF CLASS IE EQUIPMENT
Enclosed are the generic questions and answers which resulted from NRC Task
Group/Licensee "workshop" meetings held recently in NRC Regional Offices
regarding IE Bulletin No. 79-01B. This information is intended to further
the understanding of the qualification review process and reporting
requirements of the Bulletin.
The further intent of this information is to assist the licensees in
providing a method of approach acceptable to the assigned NRC Task Review
Group in determining adequacy of the environmental qualification of Class IE
Electrical Equipment installed at their respective facilities.
It should be recognized that the review of the licensee's responses may
generate additional need for guidance of finalized resolution of the
environmental qualification issue.
Enclosure:
Generic Questions and Answers
to IE Bulletin No. 79-01B
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GENERIC QUESTIONS AND ANSWERS TO IE BULLETIN No. 79-01B
Question 1 IEB 79-01B indicates the scope of the task is only that
equipment exposed to a harsh environment. Enclosure 4,
Section 4.3.3 identified areas outside of containment not
exposed to harsh environmental conditions as the results of
an accident. Should these areas be included in our
evaluations?
Answer 1 No. Although the guidelines encompass all safety-related
electrical equipment and components, the scope of IEB 79-01B
is limited to only that electrical equipment which is exposed
to the harsh environments identified in action item 1,
including where fluids are recirculated from inside
containment to accomplish long-term cooling following a LOCA.
All equipment and components identified in action item shall
be included in the subsequent actions required by IEB 79-01B.
Question 2 IEB 79-01B action item 1 and Enclosure 4 indicate that
emergency procedures be used to identify equipment to be
included in the master list. Should all the equipment
identified in the emergency procedures be included in the
master list?
Answer 2 All the equipment the licensee relies upon in the emergency
procedures to mitigate design basis events that may be
exposed to a harsh environment must be identified in response
to Question 1. It is not the intent of this task to change
the existing procedures by removing references to equipment
or comments that are considered nonessential and not
environmental qualified. This master list identifies all
equipment and components that must be evaluated in response
to action item 4. A determination should be made that
sufficient equipment is environmentally qualified to permit
accident mitigation. A tabulation of other equipment or
components which are referenced in the Emergency Procedures
but are not relied upon should be available for NRC review.
Justification should also be available so that non-qualified
equipment will not be misleading to the operator.
Question 3 Is not 2 of Appendix A to Enclose 4 within the scope of this
task.
Answer 3 Only those emergency shutdown systems that could be used for
mitigation of a LOCA or HELB and are exposed to a harsh
environment identified in response to Question 1. Licensee
review should: (1) identify equipment that could be used to
achieve cold shutdown following LOCA or HELB; and (2)
determine if environmental qualification exists. For
equipment that is not environmentally qualified the licensee
should either provide plans to qualify this equipment or
provide justification that qualification is not needed to
achieve safe shutdown to meet licensing requirements
applicable to your facility.
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Question 4 What is the basis for the 340 Degrees F for 6 hours
requirement identified in Enclosure 4 and NUREG 0588, Figure
C 1?
Answer 4 For minimum high temperature conditions in pressure
suppression type containments, we do not require that 340
Degrees F for 6 hours be used for BWR drywells or that 340
Degrees F for 3 hours be used for PWR ice condenser lower
compartments. These values are from a bounding high
temperature profile (see section 1.1 and 1.2 of NUREG 0588)
that can be used in lieu of a plant specific profile,
provided that expected pressure and humidity conditions as a
function of time are accounted for.
In general, the containment temperature and pressure
conditions as a function of time should be based on analyses
in the FSAR. However, these conditions should bound that
expected for coolant and steam line breaks inside the
containment. The steam line break conditions should include
superheated conditions: the peak temperature, and subsequent
temperature/pressure profile as a function of time. If
containment spray is to be used, the impact of the spray on
required equipment should be accounted for.
Question 5 Should equipment or systems which are presently planned to be
modified as a result of actions, such as lessons learned, to
be included in the response to IEB 79-01B?
Answer 5 No.
Question 6 Will there be any other actions required when the NRC
completes its evaluation of the responses to IEB 79-01B and
any related corrective actions deemed necessary are complete?
Answer 6 The NRC staff does not foresee any additional actions for the
electrical equipment and components which are included in the
scope of IEB 79-01B; however, if new problems or concerns are
identified, appropriate action will be taken.
Question 7 Are Spare Parts required to meet 79-01B?
Answer 7 Yes. The Spare Parts are required to meet the same criteria
as the installed electrical equipment or component resulting
from the evaluation of IEB 79-01B.
Question 8 The instruction sheet for Enclosure 3 "System Component
Evaluation" indicates that outstanding items be identified.
What is the definition of outstanding items?
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Answer 8 An outstanding item is defined as that item that does not
meet the environmental qualification guidelines and
requirements of IEB 79-01.
Question 9 Are the requirements and positions in NUREG 0588 the same as
those in NUREG 0578 in relation to environmental
qualification of electrical equipment and components?
Answer 9 Yes.
Question 10 NUREG 0588 is out for comment. Does the staff expect any
significant changes which may impact this effort?
Answer 10 No.
Question 11 When it is determined, as a result of the efforts required by
IEB 79-01B, that specific equipment be upgraded, are the
guidelines in Enclosure 4 to be used?
Answer 11 As a minimum the same requirements that were used to
determine the acceptability of the electrical equipment and
components within the scope of IEB 79-013 may be used;
however, if equipment is available which meets the
requirements of IEEE 323-1974 it should be used.
Question 12 Does the Licensee Event Report (LER) requirements of IEB
79-01B supercede or chance the reporting requirements already
defined?
Answer 12 No. The requirement for reporting in IEB 70-01B does not
change the reporting requirements defined in the license
conditions.
Question 13 Are only those items known to be unqualified immediately
reportable whereas items for which there is no data or
insufficient data are open items to be resolved, but are not
immediately reportable?
Answer 13 When a determination has been made that the existing data is
inadequate or no data exists to have reasonable assurance
that the Class IE electrical equipment components can perform
their safety-related function required in the specified FSAR
environments, that is reportable per IEB 79-01B. The time and
technical judgments required to make the determination should
be based on the significance of the specific equipment,
components and the discrepancies.
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Question 14 Are the results of an evaluation using the materials
identified in Enclosure 4, Appendix C, ,of an acceptable
method of addressing the effects of aging within the scope of
Bulletin 79-01B?
Answer 14 Yes, for those materials on the list, however, Appendix C
indicates this is a partial list. Your evaluation in response
to IEB 79-018 may identify other materials that are
susceptible to significant degradation.
Question 15 What are the sources Appendix C-1 used to identify the
material's in Table C-1 and establish the failure levels?
Answer 15 Typical sources for the information are given in Appendix C.
Your information of materials not on this table should
identify the source for your evaluation.
Question 16 Is additional effort or calculations required for radiation
service conditions if previous efforts did not utilize the
methodology or assumptions identified in NUREG 0588?
Answer 16 Yes, the extent of the effort required will be dependent on
the significance of the difference in methodology and
assumptions.
Question 17 Will extension of time be granted for schedules if identified
in IEB 79-01B action item 7.
Answer 17 The schedule was based on the significance of the safety
concerns relating to the adequacy of environmental
qualification of electrical equipment or components. Any
projected deviations from these schedules should be
identified to the Regional Office by a written request. The
NRC staff will make a determination on a case-by-case basis.
Page Last Reviewed/Updated Tuesday, March 09, 2021
Page Last Reviewed/Updated Tuesday, March 09, 2021