ML20149M757
| ML20149M757 | |
| Person / Time | |
|---|---|
| Issue date: | 11/04/1983 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20149M558 | List: |
| References | |
| FOIA-88-1, RTR-REGGD-01.089, RTR-REGGD-1.089 NUDOCS 8802290049 | |
| Download: ML20149M757 (185) | |
Text
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h ANALYSIS OF PUBLIC COMMENTS E*
ON
[
Regulatory Guide 1.89, Revision 1 1.
Section A - Introduction E
Coment 1:
5 L8 Where the term, "important to safety" is used, we recommend inserting the term E
[
Class IE instead.
All electric equipment required to perform a safety function is commonly referred to in industry standards and NP.C regulatory documents as f
Class 1E.
For this equipment, qualification requirements are contained in national standards, regulatory guides, and certain NRC publications (DOR
{
Guidelines, NUREG-0588).
These documents were written to delineate the quali-
[
fication requirements for Class IE equipment only.
It is therefore appropriate f
to use the terminology, "Class IE" rather than "Important to Safety" throughout r
this Regulatory Guide.
E.
l Comment 2:
L The term "important to safety" is used in the second paragraph of page 1.
Recomend inserting the term class 1E before "electrical equipment" in the second and third paragraphs.
Delete the term "important to safety" in the first line of the second paragraph.
b L-Comment 3:
3 E
The term "important to safety" either needs to be further defined and/or changed to "safety-related".
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Coment 4:
The title and reference to equipment should be prefixed by "Class IE."
Coment 5:
The use of "electrical equipment important to safety" is misleading and inconsistent with the reference to 10CFR Sectivi 50.49 which only deals with Class 1E and some specific non-Class 1E equipment.
Response (Coments 1 thru,5 :
j The scope of the final rule and the Regulatory Guide goes beyond class 1E or safety-related equipment.
For example, the scope incluues "associated circuit" as defined in Regulatory Guide 1.75.
Therefore, the use of the term "important to safety" is appropriate.
However, it should be noted that the final rule and this Regulatory Guide do not cover all electric equipment important to safety.
The scope is explicitly defined in paragraphs 50.49(b)(1), (b)(2) and (b)(3) of 10 CFR Part 50.
2.
Section B - Discussion Coment 1:
The phrase "(with margin)" is incorrect.
The sentence (page 2, paragraph 3, last sentence) speaks of specifications, not qualification envelopes.
Margin is added to specifications (perhaps conservatively calculated) to derive qualification envelopes.
Coment 2 In section B, the third paragraph, the last sintence is unclear.
The se'ntence says, in part, "The specific environment for which individual equipment must be 11/4/83 2
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k qualified will depend on... the length of time (with margin) it is required to operate."
Of courte, the intent of the words "to operate" is "to operate to perform its safety'related function".
The confusion in this sentence is in the phrase "(with margin)".
Time margin is applied during testing to the specific environmental conditions which are based on the time that the equip-ment is required to operate to perform its safety related function.
Such application of time margin is discussed under Position C.6.
To require that time margin be applied before determining the environmental conditions and to require that the time with margin be used to determine those environmental conditions is without basis and could impose unnecessarily severe requirements without an improvement in safety.
To avoid this improper use of tima margin, it is recommended that the phrase "(with margin)" be deleted from the sentence referenced above If it is the intention of the staff to introduce and require this new concept for time margin, a detailed basis must be presented and the value and impact must be addressed.
Opportunity should also be made available for public comment on this baifs.
_ Comment 3:
The discussion accepts as fact that "margin" be added to length af time for operation.
We suggest deletion of the parenthetical modifier.
Comment 4:
We recommend deleting the term "(with margin)," as the term used is confusing with regard to its application.
As used, it connotes that margin has a relation-ship to operating time only.
Comment 5:
Recommend deleting the term "(with margin)." The term used here adds to the confusion regarding its application.
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Comment 6:
Delete the parenthetic expression "with margin," since margin is addressed in detail in the Position section.
Comment 7:
Delete "(with margin)".
There is no margin on the length of time operation is required.
Response (Comments 1 thru 7):
The staff agrees to dolote the modifier "(with margin)".
Comment 8 Perhaps "accounted for" rather than "simulated" is a more realistic approach.
"Closely as practicable" has no meaning and needs definition if at all possible.
(Page 3, 2nd line)
Comment 9:
To simulate "as closely as practicable" is subjective and cannot be measured.
If possible, thls needs to be defined or else deleted.
Response (Comment 8-9):
The staff agrees.
The sentence containing the words "simulated" and "closely as practicable" has been deleted.
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k Comment 10:
"Exposed to a fluence" is incorrect since exposure is a fluence.
(Page 2, last line)
Coment 11:
We recomend replacing the term "fluence" by "radiation" since the latter is more widely employed in the nuclear industry.
l Coment 12:
Recomend substituting the word radiation for the term "a fluence",
The word "fluence" is not in Webster's New World Dictionary, Comment 13:
Replace the word "fluence" wit 5 "radiation," since fluence is not a widely recognized term.
Response (Comments 10 thru 13):
The staff agrees.
The word "fluence" has been replaced by "radiation."
Comment 14:
This paragraph (Page 2, Paragraph 3) states that it is essential that equipment be qualified to meet its performance requirements under all conditions.
We contend that Class 1E equipment must be qualified only to perform its safety functions following those accidents where the particular safety function is required.
The requiremert to qualify equipment to meet non-Class 1E performance 9
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requirements is not required for plant safety and is outside the scope of this guide.
It is recommended that the first sentence of the third paragraph be rewritten as follows:
"It is essential that Class 1E equipment be qualified to demonstrate its Class IE performance requirements under the environmental and operating condi-tions which are postulated to occur following a design basis event and for a length of time post-accident which encompasses the required duration of the safety function."
Comment 15:
Recommend revising sentence (Page 2, paragraph 3, first sentence) to read as follows:
"It is essential that class 1E equipment be qualified to show that it can perform its safety function under the environmental service conditions in which it will be required to function and for the length of time its function is required."
The term "performance requirements" is open to diverse interpretations, ar.d is normally used to specify a wide variety of equipment design and functional capabilities.
These design and functional capabilities are not always neces-sary to define the safety functional requirements of the equipment.
Therefore we recommend the use of the term "safety function".
Comment 16:
The paragraph (Page 2, paragraph 3) should state "safety function" specifically instead of "performance characteristics." Change "environmental and operating conditions" to "environmental service conditions."
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u W
u Response (Comment 14 thru 16):
This paragraph has been revised to reflect the intent of these comments.
Comment 17:
We recommend deletion of this paragraph (Page 3, 1st paragraph).
The inclusion of non-Class 1E equipment is incompatible with the scope of this guide.
Should an item currently classified as non-safety related equipment be identified as capable of negating a safety function due to an accident condition, then such an item is improperly classified and must be reclassified as Class 1E to fall within the scope of this guide.
The sht'ety function of such an item of equip-ment is defined as "not to fail in a manner capable of defeating the safety function of other Class IE equipment" in order to meet the single failure requirements of IEEE 279 as endorsed by 10 CFR 50.55a(h).
The whole subject of Systems Interaction is actively being investigated by the Staff under Generic Tasks A-17 and A-47.
We believe it inappropriate to introduce requirements relating to this issue via Regulatory Guide 1.89 when the Staff is in the process of developing detailed guidance on this complex issue.
Comment 18:
On page 3 we recommend deleting the first paragraph which begins with "Regulatory Position C.1...." This regulatory guide should not address the qualification of equipment other than Class 1E.
The requirements for classification and qualification of other equipment should be and is identified in other regulatory guidance addressing the need for that qualification.
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J f
Comment 19:
3 y
p The term "essential" is introduced to define the scope of systems and equipment that should be qualified to perform their intended function.
It is suggested
-i that this term be eliminated and that consistent terminology be used throughout b
the guide when referring to the scope of the equipment requiring qualification, k
The terminology that is suggested is equipment that is required for emergency a
i reactor shutdown, reactor core cooling, core residual heat removal, containment
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~
R isolation and prevention of significant release of rad!oactive material to the y
j environment.
g_
Comment 20:
y Recommend deleting this paragraph (Page 3, first paragraph) which begins q
with "Regulatory Position C.1..."
l 7
This regulatory guide should not require qualification of any equipment other
]
than class 1E.
The requirements for qualification of other equipment should g
be identified in other regulatory guidance that would address the need for that qualification.
j 1if N
-5 2
Response (Comments 17 thru 20):
The scopes of the final rule and this Regulatory Guide extend beyond Class 1E 5
m equipment.
Thus, it is not inconsistent to include eouipment (e.g., associated A
j circuits) whose failure under accident condition could cause failure of Class 1E j
circuits or equipment.
]
2 i
g The term "essential" has been deleted and the paragraph has been modified to L
be consistent with final rule.
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Comment 21:
O'_
Delete the word "testing" from line 2 (Page 4, 1st paragraph).
Qualification can be demonstrated by other means.
Comment 22:
i
?
5 In section B, the last paragraph, the first sentence implies that the qualification of equipment located in a potentially harsh environment can only be demonstrated through testing.
This implication is not justified.
IEEE 323-ggg[
1974 provides several acceptable methods for qualification and g bases have been provided for rejecting these methods.
This sentence should be rewritten to say that the qualification of Class 1E equipment is based on the use of expected environmental conditions throughout the installed life of the equip-ment and during a postulated DBA ac required.
Comment 23:
We recommend revising the 1st paragraph on page 4 as follows:
"Class 1E equipment qualification is predicated on the assumption that qualification methods adequately address the environmental service conditions throughout the installed life of the equipment.
Where *outine maintenance is essential to u intaining qualification, it is important to establish an adequate program of preventive maintenance and quality assurance to insure the ability of the equipment to perform its safety function."
Comment 24:
With regard to t'.ie lut paragraph of Section B, we agree that maiitrance is an f:::portant activity in assuring the safety-relat6d equiprtent will function properly.
We disagree, however, with the statement in the paragraph's first sentence that qualification testing can or need simulate all environment and service conditions.
We further disagree with the inference that testing is 11/4/83 9
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WT the only acceptable method of qualification.
As has been stated to the Staff on many occasic.ns, the purpose of environmental qualification (regardless of the method) is to provide an adequate level of assurance that common-mode equipment failures do not occur as a result of hostile environmental stresses.
Furthermore, the emphasis is on "cleanness" and "dust accumulation" are poor examples of inappropriate preventive maintenance activities.
Comment 25:
The last paragraph should prefix "equipment" with "Class 1E."
Revise the last sentence to read, "Where routine maintenance is essential to maintain qualifi-cation, it is important to establish an adequate program of preventative maintenance and quality assurance to insure that the Class 1E equipment functions properly."
Comment 26:
The mention of "minimizing dus,t accumulation" is out of context and should be deleted as no requirements or reasons are spelled out in the Guide.
Comment 27:
Why mention "minimizing dust accumulation" unless there is a reason and a specific requirement to be called out in the Guide?
Comment 28:
In section B, the last paragraph, the last sentence, the intent of the sentence is confused by the specific reference to dust accumulation.
The meaning of the sentence would be clearer if rewritten as follows "Where routine mainte-nar.ce is essential to maintaining equipment in the conditions simulated by the qualification test (e.g., cleanness), it is important to establish an adequate 11/4/83 10 1AGGAR/A
W program of preventive maintenance and quality assurance to ensure the ability of the equipment to perform its required safety function."
Comment 29-Replace "that includes minimizing dust accumulation..." with "whi:h minimizes phenomena (e.g., dust accumulation)..."
Response (Comments 21 thru 29):
The qualification can be demonstrated by other acceptable methods (see paragraph 50.49(f)) of 10 CFR Part 50.
This paragraph has been reworded to illustrate the relationship between maintenance / quality assurance and qualifi-cation.
Reference to "dust accumulation" has been deleted.
Comment 30:
Changed "dated" to "published" February 28, 1974 to clarify the actual chain of evwnts, i.e., approval precedes publication.
(Page 2 Paragraph 1)
Response
The staff agrees.
The change has been made.
Comment 31:
The term "containment test conditions" requires definition.
(Page 2, paragraph 2)
Response
The words "containment test conditions" have been deleted.
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Comment 32:
This paragraph (Page 2, paragraph 2) implies that "qualification" is required to confirm the adequacy of equipment design for the performance of safety functions under normal and abnormal conditions, as well as accident conditions.
Qualification has historically been defined as the verificatien by type testing, analysis, and/or operating experience that equipment is not susceptible to common-mode failure resulting from the substantial additional stresses resulting from design basis events.
Since normal and abnormal conditions typically do not subject the equipment to significant stresses, common-mode failures are not expected due to these conditions alone.
Extensive equipment operating experience in both nuclear and fossil plants substantiates this claim.
The design of equipment for normal and abnormal conditions is verified by a number of activities including conservative design practices using industry codes and standards verified in accordance with quality assurance programs, manufacturcrs' type and rating tests, operating experience, preoperational tests prior to system startup, periodic tests, and maintenance / surveillance programs.
Therefore, qualification requirements should not be applied to equipment subjected only to expected normal and abnormal conditions (i.e., mild onvironments).
Response
For the purposes of this guide, "qualification" requirements will apply to electric equipment important to safety which may be exposed to design basis accident ci.1ditions.
This guide provides specific guidance for qualification of electric equipment for environments resulting from LOCA and MSLB.
E f
Comment 33:
E The Regulatory Guide should include the "Supplement to the Forward of IEEE 323-1974" which clarifies the concept of aging.
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Response
The staff disagrees.
Adequate guidance on aging has been provided in the final rule and the Regulatory Guide.
Comment 34:
\\
The proposed regulatory guide is not clear in most areas as to which discussions or positions apply to mild environments, harsh environments or both.
5 For example, in section B, the last paragraph, the first sentence says that qualification is "predicated" on "qualification testing".
- However, position C.S.a. clearly states that certain equipment (not in harsh environ-ments) need not be qualified by test.
The referenced sentence in Section B should have the qualifying phrase "for equipment located in potentially harsh environment" added.
Comment 35:
9-ference should be made in this section to the evaluation criteria for equipment in inild environments.
This would inform the licensee that Section C.S.a is the applicable section and eliminate the confusion of interpreting criteria intended for equipment in harsh environtnents.
Response (Comments 34-35):
The scope of this guide does not include requirements for equipment located in mild environment.
However, guidance has been provided under section B, "Discussion."
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W i
Comment 36:
The fourth paragraph in Section B calls for simulating actual "dose rate, spectrum, and particle type unless it can be shown by analysis that damage is not signi ficantly dependent,..." Such analysis may not be feasible, forcing use of multiple radiation exposures (gamma, beta, and neutron) for low dose rates during normal conditions with little real benefit.
Industry could spend many months or years just doing radiation exposure.
This requirement should be clarified to be applicable to the limiting accident conditions only.
Such an assumption will make effective use of both industry and NRC manpower.
Comment 37:
The fourth paragraph of this section discusses the qualification of equipment in a nuclear radiation environment.
It is stated that:
"Dose rate, spectrum, and particle type should be simulated as ciosely as practicable unless it can oe shown by analysis that damage is not significantly dependent on dose rate, spectrum or particle type."
This statement is in contradiction to paragraph 6.3.4 of IEEE std 323-1974 where accelerated exposure rates are permitted to facili-tate the use of reasonable test times.
If this area is truly a concern, the requirement should only be applied where an effect is known; otherwise, the added margin, as required by IEEE std 323-1974, paragraph 6.3.4, should be acceptable.
Comment 38:
There is an apparent contradiction within the guide with respect to dose rate, spectrum and particle type for the radiation type.
In section B, the fourth paragraph, the last sentence ;eads, "Dose rate, spectrum, and particle type should be simulated as closely as practicable unless it can be shown by analysis that damage is not significantly dependent on dose rate, spectrum, or particle type."
The sentence implies that nearly every qualification test program will require an analysis since, in the practical world, the source used for 11/4/83 14 1AGGAR/A
~
Q qualification testing cannot "... simulate as closely as practicable..." the dose rate, spectrum and particle type.
Comment 39:
Compliance with simulation of the dose rate, spectrum and particle type as closely as practicable to the accident is not practical on a project basis since the conditions are functions of the type and severity of the accident.
The determination of the effects of various combinationc of dose rates, spectrum, and particle type is a research program that should be performed by the NRC or an industry organization such as EPRI.
Comment 40:
Second line.
Recommend deleting sentence page 3, first paragraph, beginning with "Dose rate, spectrum..."
The state of knowledge in this area of material research is not sufficiently developed.
Full development of the knowledge is required to establish conclusive evidence that the presently employed techniques for radiation testing may not conservatively address the effects of dose rate, spectrum, and particle type.
Comment 41:
Delete the sentence, "Dose rate, spectrum, and particle type... " from the fourth paragraph.
Replace "electric equipment" with Class 1E equipment."
Comment 42:
The second sentence Section B, Paragraph 4 should be rewritten or deleted.
For gamma and beta radiation neither spectrum nor particle type are simulated "as closely as practicable" in current qualification testing programs.
Generic 11/4/83 15 1AGGAR/A
W analyses have already been performed (NUREG/CR-1237) to sho~w that a post-accident fission product gamma spectrum can be adequately simulated by a Co-60 or Cs-137 source.
That report also shows that gamma tests performed at equivalent dose levels will conservatively simulate beta radiation environments.
Since spectrum and particle type have been treated generically in the NUREG, the Regulatory G'Jide should not require the expenditure of resources to reanalyze these effects on a case-by-case or plant-by plant basis.
This should also be reflected by changing Section C.5.h to read:
"Cobalt-60 or Cesium-137 would be acceptable for environmental qualification for both beta and gamma-ray environments."
Comment 43:
The inclusion of dose rates as a criteria is inappropriate since it is beyond present testing program technology.
Comment 44:
The statement that "dose rate, spectrum and particle type should be simulated as closely as practicable unless it can be shown by analysis that damage is not significantly dependent on dose rate, spectrum, or particle type", imposes an unnecessary burden on demonstration of qualification.
Historically, testing programs (with some limited, specific exceptions) have not considered dose rate, spectrum, or particle type effects.
Rather, most programs have used 60 137 Co or Cs gamma radiation from sources producing up to about 106R/hr to simulate equipment radiation environments.
Literature on the subject has not revealed significant dose rate effects to most materials used in nuclear power plants (with the possible exception of some electronic equipment) at the maximum dose rates anticipated following an accident.
Therefore, rather than require examination of all pieces of equipment 11/4/83 16 1AGGAR/A
~ i for dose rate effects, a more effective focus of attention might be directed at only certain, specific types of devices.
To our knowledge, no one has ever simulated an actual accident radiation energy spectrum for use in an equipment qualification program, or would even know how to do so in the future if so inclined.
There is no reason.able way to approximate the spectrum from the 100 or so radionuclides assumed released from the core.
Requiring analyses to show that the 60 gamma spectrum, for Co example, would adequately simulate the effects of the actual spectrum to all material and components, would result in a meaningless, academic exercise.
In addition Section C, Position 5.1 appears to render the discussion moot in allowing 60 r 137 as gamma sources.
Clarification of the NRC's intent is Co Cs called for.
Except for testing of certain NSSS components for exposure to neutron radiation, virtually all testing is done with gamma radiation.
Since all sensitive components located in the containment have some sort of covering, usually adequate to shield against beta particles (this can be demonstrated by analysis),
gamma testing alone is sufficient.
Response (Comment 36 thru 44):
In general, the staff agrees with these comments.
Section B, paragraph 4 and position C.4.C(5) have been modified to reflect the revisions.
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C.
Regulatory Position Section C1 l
Comment 1:
l The current wording of Paragraph C.1 significantly expands the scope both of the proposed 10 CFR 50.49 and of this Regulatory Guide by including all func-tions of essential electrical equipment.
Just because a system is labeled "essential" does not mean that all of its functio'ns are necessarily safety related. We recommend that the word "safety" be inserted in the first sentence between the words "intended" and'"functions."
Comment 2:
We suggest modifying the first sentence to state that it is "essential" electric systems and equipment necessary for safe shutdown that must be qualified.
This will clarify the applicability of the requirements.
Comment 3:
Positior. C.1. uses the terms "essential" systems and "essential" equipment.
These terms are not properly defined and, in fact, the term essential is used elsewhere in the regulations and regulatory guidance with different meanings than is intended here.
It is recommended that the word "essential" be replaced with Class 1E.
l Comment 4:
1 The first sentence of this position should be replaced with paragraph (c) of section 50.49 to 10 CFR 50.
l 11/4/83 18 1AGGAR/A l
4 Comment 5:
Recommend revising Section C1 as follows:
" 1.
Section 50.49, "Environmental Qualification of Electric Equipment for Nuclear Power Plants," of 10 CFR Part 50 would require that class 1E electric systems and equipment be quali-fied to perform their intended safety function.
Typical class 1E equipment and functions that mitigate accidents are listed in Appendix A to this guide."
Recommend deleting the remainder of paragraph C.1.
Comment 6:
Replace "essential" with "Class 1E" wherever essential appears.
Prefix "function" with "safety."
Comment 7:
Equipment does not need to be qualified for its "intended functions" but only for its required safety function.
It is recommended that the first sentence be modified accordingly.
Furthermore, it is recommended that the last two sentences which considerably expand the scope of equipment to be qualified be deleted.
The concept of environmental qualification should be applied only to redundant safety-related equipment subject to common-mode failure due to the significant environmental stresses from design basis accidents.
The application of qualification to non safety-related equipment would not significantly improve safety and could not be justified by a detailed cost / benefit analysis.
Response (Comments 1 thru 7):
Regulatory Position C1 has been revised to be consistent with paragraph 10 CFR Part 50.49(b).
The word "essential" has been deleted.
The words "intended functions" have been replaced by "intended safety functions." Refer to response to Comments 8 thru 13 under section C1.
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Comment 8:
In Position C.1., the last two sentences should be deleted and the undefined word "essential" should be replaced with Class 1E.
Comment 9:
The section "Additional equipment... Electric Systems" should be deleted.
Comment 10:
The term "essential electric systems and equipment" can only lead to confusion.
The term "Class 1E of IEEE 323-1974" should be used.
The reference to Regula-tory Guide 1.75 and associated circuits indicates that this equipment, "should be considered for qualification." By definition the use of acceptable isolation devices (IEEE 384, R.G. 1.75) and/or independence (R.G. 1.6 and 1.75) precludes the need for qualification.
For example, an isniation device must be qualified as Class 1E in order to demonstrate that the requirements are met. We note that "associated circuits" are defined in IEEE Standard 384.
Comment 11:
The last sentence of this section should be revised to read as follows:
l "For example, additional equipment that should be considered for qualification are the associated circuits defined in Regulatory Guide 1.75, ' Physical Independence of Electric Systems', unless it can be demonstrated that the availability of Class IE circuits would not be significantly reduced."
l l
l 6/16/83 20 1AGGAR/A
0,
[
Comment 12:
The final sentence of this section suggests.that the Staff will require all equipment which is part of associated circuits to be environmentally qualified.
We maintain that such a requirement is inappropriate.
Regulatory Guide 1.75 and the associated industry standard which it embraces (IEEE-384) are detailed guidance which assure that the design concept of independence is appropriately incorporated into the design of redundant safety systems.
As the Staff is well aware, independence, like environmental quali-fication, is a technique used to address common-mode failures.
Independence as a design concept addresses common-mode effects which may occur as a result of the physical and electrical interdependence of redundant safety systems.
The hazards (identified in Section 4.7 of IEEE-384-1977) which are to be considered in the application of this guidance are fires, failures of non-Category I structures or equipment and misoperation of mechanical and structural components.
This physical and electrical separation criteria and the identification of associated circuits which are addressed by these docu-ments are to be applied principally to these hazards which are not a result of the DBA LOCA and HELB.
Since such LOCA and HELB events are the primary focus of environmental qualification, qualification of such associated equipment, which has no safety function for LOCA and HELB events, should not be required.
We, therefore, recommend that the last sentence which makes reference to Regulatory Guide 1.75, Associated Circuits be deleted.
Comment 13:
Since not all essential systems and equipment are required to operate during or following an accident, the third sentence should be clarified to read, "Additional equipment should also be qualified for accident conditions if its malfunction or failure due to such conditions will negate the safety function of essential systems and equipment required during or following the accident."
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Response (Comments 8 thru 13)
The Staff agrees that using acceptable isolation devices will preclude the need for qualification.
However, the isolation device must be qualified.
This position it; consistent with Regulatory Guide 1.75.
Also nonsafety-related electric equipment must be environmentally qualified for accident conditions if its malfunctions or failure due to such conditions will negate the safety-function of safety related equipment duting or fullowing the accident.
Regulatory Guide 1.75 requires qualification of associated circuit to IEEE 323-1974.
This standard includes environmental qualification as well as a screening test for fire.
Also refer to response to comments 1 thru 7 (page 19).
Comment 14:
The words "for,1ccident conditions" and "due to such conditions" should be deleted from the third sentence of this position.
Response
The staff agrees.
The regulatory position C.1 has accordingly been revised.
Comment 15:
Regulatory Guide 1.75 is introduced as additional guidance for qualification.
This should not apply to those plants not committed to Regulatory Guide 1.75.
Comment 16:
l Inclusion of "additional equipment that should be considered for qualification are the associated circuits defined in Regulatory Guide 1.75" will require the operating plants constructed prior to 1974 to redefine the plants equipment in l
11/10/83 22 1AGGAR/A
r accordance with Regulatory Guide 1.75.
Cost for this item is dependent on the.
degree of compliance required with Regulatory Guide 1.75.
Response (Comments 15 and 16):
This Regulatory Guide does not extend the implementation date of RG 1.75, Revision 2.
Comment 17:
The qualification of "additional equipment" should be dictated by separate guidance, such as Regulatory Guide 1.75 or 1.97.
Comnent 18:
We recommend deleting the 3rd & 4th sentences of Section C1 starting with, "Additional equipment should also be quantified... " The application of Regulatory Guide 1.89 to "additional equipment" should be dictated by separate guidance; i.e., R.G. 1.75 and R.G. 1.97 as implemented.
Response
(Comments 17 and 18)
The Commission has decided, after considerable deliberation, to include certain i
l non-safety related equipment and certain post accident monitoring equipment within the scope of the final rule Section 50.49 of 10 CFR Part 50.
Thus, it is included within this guide, which describes acceptable ways to meet the rule.
f 11/4/83 23 1AGGAR/A
e A.
Section C2 Comment 1:
We disagree that seismic and environmental qualification testing must be performed on a single equipment prototype.
The NRC staff apparently believes that the most severe accident sequence to which a component must be qualified is the occurrence of a Safe Shutdown Earth-quake ("SSE") with a simultaneous or causal linked Design Basis LOCA.
The probability of simultaneous (i.e., within the same year), but independent SSEs and LOCAs of any size is diminishing 1y small.
(Ref. WASH-1400) This require-ment for the sequential simulation (of seismic vibration and LOCA environmental parameters during environmental equipment qualification, must therefore result from a strong belief by the Staff in a causal link, i.e., that an SSE generates a LOCA.
The main body of probabilistic risk assessment work done to date for nuclear power plants has consistently provided quantitative evidence that for seismic events equal to, or less severe than the SSE the sequence of an e:1rthquake causing a LOCA is an extremely small contributor to overall risk.
One reason that the sequence does not occur is the requirement in the ASME codes and the industry's licensing basis to design piping systems and components for such a l
simultaneous occurrence, thereby providing significant design margin.
This piping system design margin (SSE plus LOCA) should not arbitrarily be the only l
rationale for applying the same design margin for electrical equipment environ-mental qualification.
Earthquakes do create risks for nuclear power plants, but the important fact that must be kept in mind is that those accident sequences that are significant risk contributors which result from design basis earthquakes do not contain LOCAs.
The significant sequences for seismic events contain failures in struc-tures, equipment and systems OUTSIDE the reactor coolant pressure boundary, 11/4/83 24 1AGGAR/A l
l
s This point has been developed in various industry documents.
(Ref. WASH-1400; NUREG CR 2189; EPRI-NP-SP)
No sound technical basis exists which suggests that safety related electrical equipment should be designed and qualified to the conditions resulting from a concurrent SSE and LOCA.
A growing body of knowledge (presently embraced in the German licensing process) suggests that for all systems, structures and components, the SSE and LOCA loading combinations should not be required as a design basis.
Recognizing that power plants are presently licensed in the United States with reactor coolant system piping and components designed for such a load combin-ation, the probability of the concurrent SSE plus LOCA environmental effects resulting from RCS piping and component failures on electrical equipment is vanishingly small.
The Regulatory Guide requirement that qualification encom-pass concurrent SSE and LOCA, therefore, must be revised.
Finally, we would like to point out that the qualification testing presently conducted to these requirements essentially qualifies in-containment equipment to the simultaneous occurrence of three highly-improbable events.
There are (1) a Safe Shutdown Earthquake, (2) a maximum size double-ended pipe break Loss of Coolant Accident, and (3) a significant degraded core event with source items released to the containment equivalent to those in TID 14844.
Recognizing that this current industry qualification practice is highly conser-vative, we question the Staff's focus on equipment qualification as being a significant safety issue.
If the Staff's basis for such a heightened concern is the failures which have occurred during qualification testing, then we maintain that the present practice of overqualifying equipment and not the existence of equipment in actual service which would not adequately perform is the reason for these qualification testing failures.
We, therefore, recommend that the last sentence of Section C, Item C.2, which beings "However, the testing..." be deleted.
6/16/83 25 1AGGAR/A
Response
The staff agrees that the probability of occurrence of a SSE with a simultaneous or causal linked Design Basis LOCA is very small.
For qualification of electric equipment, the staff believes that the test sequence described in IEEE 323-1974, using Regulatory Guide 1.100 is conservative and therefore preferred.
The staff has deleted the last sentence from Section C2.
Note that the use of any provision of the Regulatory Guide 1.89 by operating plants and NT0Ls is optional, except for replacement equipment.
Comment 2:
The requirement that "testing should be performed on a single prototype in the sequence indicated in Section 6 of IEEE Std. 323-1974" is technically unjusti-fied and inappropriate.
The sequence indicated is operational testing, age conditioning, seismic vibration, non-seismic vibration, and exposure to accident and post accident conditions.
IEEE Std. 323-1974 does not require that the same sample be used for both seismic and accident (LOCA) conditions, although this is almost always done in practice for convenience and economy.
Because the 1974 standard is sometimes interpreted to require the same sample for both test conditions, the latest draft 011 of the revision to IEEE 323 contains the following clarification; "Note:
Use of the same sample throughout the test sequence is an economy measure and represents the most conservative case.
The user of this standard should not infer that the sequence used implies a coupling among the various 08E's postulated for any given plant." This issue goes beyond equipment qualification since it impacts many areas of plant safety and licensing.
If sound technical information developed in recent years is not applied, the industry may drift toward acceptance of seismically induced LOOA's as a credible design basis accident sequence in all areas.
Much evidence has been and is being generated to show that the probability of a seismic /LOCA 11/10/83 26 1AGGAR/A
4 2
linkage is too small to be included as a credible design basis consideration.
Among the studies confirming this fact are:
(1) WASH-1400 (NUREG-74/014) -- Section 5.4.1 of the main report discusses earthquake risk and the-issue of LOCA caused by earthquakes is not considered.
(2) EPRI-NP-1804-SR, "German Risk Study Main Report" (English Translation) --
Section 5.3.2.5 indicates that "... the failure of components of the reactor coolant and secondary coolant system (within the containment) during a safe shutdown earthquake (SSE) is not assumed, since the dynamic stresses in the safety earthquake remain significantly below the design loads of these system components."
(3) NUREG/CR-2189, "Probability of Pipe Fracture in the Primary Coolant Loop of a PWR Plant," (Vol.1:
Summary of Load Combination Program, Sept. 1981)
It is concluded in the Abstract that for a PWR similar to Zion Unit 1, "Results of the simulation indicate that the probability of a double ended guillotine break, either with or without an earthquake, is very small (on the order of 10 12),n (4) Zion Probabilistic Safety Study -- Section 7.2 indicates that large LOCA events cannot be induced by the range of possible seismic events at the Zion site.
This conclusion arises from the high earthquake resistance of the pressurizer, the pressurizer enclosure roof, and large diameter piping.
We recommend that the last sentence in C2 be revised to read:
"iiowever, the testing for each postulated set of design basis events, should be performed on a single prototype in the sequence indicated in Section 6 of IEEE Std. 323-1974.
Simulated conditions from more than one postulated set of design basis events may be applied to a single prototype if the combined application represents a more conservative condition."
6/16/83 27 1AGGAR/A
F t
Comment 3:
In Position C.2., the last sentence implies that the recommended sequence in Section 6 of IEEE Std. 323-1974 is the only acceptable sequence.
The interpretation has always been that alternate sequences can be used if shown to be more conservative.
Add the following sentence to the end of the position:
"Other sequences may be used if shown to be more conservative for the item being tested."
Comment 4:
The last sentence implies that qualification testing for all design-basis events (e.g., LOCA, MSLB, SSE) must be performed sequentially on a single prototype.
Design-basis events (DBE's) are independent events for which tee simultaneous occurrence can be considered not to be credible.
It is recom-mended that this sentence be modified to state that the qualification testirig for any single DBE should be conducted sequentially on a single prototype.
Note that tests are typically run for several DBE's on one prototype for economical reasons only.
Response: (Comments 2 thru 4)
See Response to Comment 1 under section C2.
Comment 5:
Position C.2. applies to equipment located in a harsh environment.
Add the phrase, "for equipment located in a potentially harsh environment," to the last sentence in this position.
11/4/83 28 1AGGAR/A
-q i
Comment 6:
In the last sentence, we recommended adding verbage to clarify that the testing by type as specified applies only to equipment located in a potentially harsh environment.
Comment 7:
Recommend revising last sentence to read as follows:
"However, for equipment located in a potentially harsh environment the qualification testing should be performed on a single prototype in accordance with Section 6 of IEEE Standards 323-1974."
Comment 8:
With regard to the last sentence of Section C.2, this Guide apparently requires the use of the exact test sequence described in IEEE 323-1974,~Section 6.
This is an inappropriate requirement since in certain cases deviations from the sequence are appropriate and justifiable.
Response (Comments 5 thru 8):
The last sentence from Regulatory Position C2 has been deleted.
The staff position continues to be that the test sequence as described in IEEE 323-1974 is preferred and the "full" test sequence does net apply to equipment located in a mild environment.
Comment 9:
This position should state in detail the methods acceptable to the NRC staff for seismic testing or categorically state that IEEE 344 as endorsed by 11/4/83 29 1AGGAR/A
4
+
Regulatory Guide 1.100 is a complete and acceptable document on which to base seismic' testing.
Comment 10:
We believe this regulatory position should give more detailed guidance on seismic qualification requirements for plants which (1) licensed before IEEE-344-1971 issue, (2) committed to IEEE-344-1971, and (3) which qualified equipment to IEEE-323-1974 (which endorsed IEEE-344-1971).
In the absence of this guidance, qualification tests which meet IEEE-323-1974 and IEEE-344-1975
~
could invalidate the original plant qualification (seismic) of devices such as panels, cabinets, enclosures, etc., on which these devices are to be mounted.
This Section recommends sequential testing on a single prototype as indicated in Section 6 of IEEE Std. 323-1974, which includes seismic qualification.
Section 50.49(g)(4) of the Proposed Rule also mentions sequential tests for equipment qualified by test; but, Section 50.49(a) clearly states that seismic and dynamic qualification is not included.
The confusion in the Rule is further compounded here by references to IEEE Std. 344-1971 and to Regulatory Guide 1.100, which endorses IEEE Std. 344-1975.
Response (Comments 9 and 10):
For seismic testing, the qualification in accordance with Regulatory Guide 1.100, which endorses IEEE 344-75, is acceptable.
Comment 11:
Change "prototype" to "prototype (s)" since the sentence infers one specimen only whereas usually more than one identical units are tested to expedite testing in case of a random failure.
11/4/83 30 1AGGAR/A
O
^
Comment 12:
Ti.e reference to a "single" prototype is unnecessary.
Further, it seems to:
(1) specifically require only 1 unit to be tested, and (2) implicitly endorse the concept of type-testing of a single unit rather than a statistical test approach.
Comment 13:
The word ' prototype' should be reclaced with ' test specimen'.
Response (Comments 11 thru 13):
The staff does not require a large sample of protype to be used in qualification testing in order to yield a statistical basis for acceptance.
The satisfactory performance of several prototypes is preferred.
Comment 14:
The last sentence concerning test sequence should be deleted.
Regulatory Guide 1.100 does not require qualification by test only, neither does IEEE 323-1974 require a single prototype be employed for the full test sequence, where testing is the qualification method, as stated in 6.3.2(3) of that standard.
Response
The last sentence has been deleted.
IEEE 323-1974 requires a single prototype be employed for full test sequence.
The staff considers this test sequence to be conservative and preferred, but may accept qualification resulting from the use of two prototypes (one for seismic, one for environmental).
See response to Comment 1 (page 26).
11/4/83 31 1AGGAR/A
.o Comment 15:
This paragraph indicates seismic qualification testing is to be done on a single prototype in accordance with IEEE-323-1974.
This does not allow for equipment which has already been tested using other means.
Response
The staff does not require retesting for environmental stresses simply because a single prototype was not used during the original qualification for environ-mental and seismic conditions.
(See paragraph 50.49(k) of 10'CFR Part 50.
Section C3 Comment 1:
The statement is made that qualification by analysis is not acceptable unless testing is impractical because of size, state-of-the-art, or the equipment purchase order was executed prior to May 23, 1980.
This implies that qualifi-cation by test is the only a:ceptable means for equipment with purchase orders executed after May 23, 1980.
It is unreasonable to think that an item which has been fully qualified in accordance with IEEE Std. 323-1974 and purchased after May 23, 1980 is not qualified because a combination of analysis and partial type-test data was used to qualify it.
To state a point in time which would allow or disallow the use of analysis does not improve the ability to operate a nuclear power generating station safely.
It only increases the cost of operating that station.
Comment 2:
The clear implication of this regulatory position is that for equipment whose purchase is after May 23 196:, snalysis in combination with partial type test data is not acceptable.
I believe this is an absolutely improper implication to leave.
Almost any type testing program relies upon analysis, usually of 11/4/83 32 1AGGAR/A
I several types.
To imply that unless one has type testing of exactly the profile used for a given station, on exactly the proper equipment with perfectly speci-fied operating requirements and test data, is I believe, placing a hopelessly impractical burden on any equipment qualifier.
No positive guidelines are given for what requirements are appropriate for equipment purchased after May 23, 1980.
Certainly, IEEE 323-74 does indicate a combination of analysis and partial type testing may be adequate for qualification.
Comment 3:
We recommend deleting this section as it strongly infers that analysis is not an acceptable technique to address equipment qualification.
We maintain that analysis, when supported by test data which adequately support the analytical assumptions and conclusions, is a valid means of addressing equipment qualifi-i cation and that this is a valid concept regardless of the individual plant commitment to a specific qualification standard.
Also there is no technical justification for eliminating the uso of analysis supported by test data as a means of demonstrating qualification beyond the given cutoff date.
Comment 4:
This regulatory position should be revised to remove the May 23, 1980 limitation.
Analysis based on type-test data should always be acceptable if it adequately demonstrates qualification.
Response (Comments 1 thru 4):
The staff agrees.
The cut-off date of May 23, 1980, has been deleted.
NRC prefers testing, and it will accept analysis in combination with partial type test data that supports the analytical assumptions and conclusions.
11/4/83 33 1AGGAR/A
Section C4 Comment 1:
The Standard Review Plans (SRP) are not appropriate references for use in regulatory guides since they are an internal NRC document and not subject to public review and comment.
Thus, we recommend that references to SRP's be deleted from this guide and specific guidance included.
l Comment 2:
References to SRPs should not be allowed unless they are specifically dated.
They might be changed or revised in some way and reflect back into the Guide.
I suggest lifting the appropriate phrases and making the Guide a stand alone document.
Comment 3:
The Standard Review Plan (SRP) should not be referenced in the Regulatory Guide since the SRP can be modified without the same public review and comment required for the Regulatory Guide and the SRP is not applicable to most operating plants.
The requirements should be stated explicitly in the Regulatory Guide.
In addition, the requirements imply that operating plants would have to recal-culate their LOCA and MSLB containment profiles using the latest industry codes.
This would significantly impact the qualification efforts of operating plants without a significant improvement in safety.
We do not believe this is the intent of the NRC Staff and recommend that operating plants be allowed to use the containment profiles calculated as part of their licensing basis.
l Comment 4:
The mass and energy release rates methods referenced in Section C.4a this Guide, the industry codes discussed in C.4.a(1), and references to the guidanc,e 11/4/63 34 1AGGAR/A
of NUREG-0800, "Standard Review Plan" (SRP), may be appropriate for plants which have used these methodologies for such calculations.
For operating plants which have used earlier methods there is no rational technical need to recalculate such environmental parameters.
The Staff has previously accepted for use in environmental qualification the conservative bounding accident parameter values developed as the FSAR contain-ment licensing calculations and should continue f.o do so.
We recommend that this Guide be modified to indicate acceptance of FSAR analyses referenced in Licensee's IEB 79-018 and NUREG 0588 submittals.
Response (Comments 1 thru 4):
The staff agrees that reference to SRPs should not be made.
Also see Response
~
to Comment 6 (Page 36).
Comment 5:
The paragraph (Paragraph C.4.b) reference to Standard Review Plan Section 6.5.2 should be corrected to read "subsection II.1.e" in lieu of "paragraph II, item (e)".
Response
The staff agrees.
However, any reference to SRP has been deleted.
Comment 6:
The mass and energy release rates methods identified in Appendix B to this Guide, the industry codes discussed in item 4.a(1), and this item's r9ference to the guidance of NUREG-0800, "Standard Review. Plan (SRP), although conser-vative, may be appropriate for plants which have used these methodologies for 11/4/83 35 1AGGAR/A
such calculations.
For operating plants wt.ich have used earlier methods there is no rational technical need to recalculate such environmental parameters.
The Staff has historically accepted for use in ensironmental qualification the conservative bounding accident parameter values developed as the FSAR contain-ment licensing calculations.
(See Staff Clarification Document Issue 7, Containment Service Conditic,ns; DOR Guidelines Section 4.'1; Sections of standard NRC letter
Subject:
Environmental Qualification of Safety-Related Electrical Equipment which transmitted the Staff's SERs cn environmental qualification of Class IE equipment to individual licensees; Section 3.2 Service Conditions of those SERs.)
Response
Use of any provisions of this Regulatory Guide for operating plants or NTOLs is optional, except for replacement equipment.
Comment 7:
Composition of chemical spray solutions should be based on plant-specific designs, particularly for existing operating plants.
(Paragraph C.4.b)
The paragraph is inappropriately titled.
The issue addressed is the need to consider the effect of operation of the containment spray system during equip-ment qualification.
We recommend that Item C.4.b to be retitled and reworded as follows:
l l
Effect of Containment Spray:
The effects of contains. : spray system I
operation should be considered.
This consideration should include, as appropriate, the effect of demineralized water spray or chemical spray l
systems.
Additional information on the chemical composition and chemical properties of such systems are provided in SRP Section 6.5.2 paragraph II, item (e).
11/4/83 36 1AGGAR/A
Response
The staff sgrees.
The paragraph C.4.b has been modified.
Comment 8:
Previous Staff guidance on the temperature conditions to be used for MSLB inside-containment qualification evaluations permitted the use, with certain restrictions, of LOCA temperatures.
(See DOR Guidelines Section 4.2.
See also NUREG-0458.) The Staff has previously stated that, if justified by licensees, the use of the Staff's screening criteria for MSLB temperatures, T
f r PWRs and TSAT + 20 F for BWRs, was considered acceptable.
See NRC SAT document Prediction of Temperature, Pressure and Humidity Conditions Following Accidents distributed during the July, 1981 NRC meeting on enviror. mental qualification held in Bethesda, Maryland.
Finally, the Staff has previously provided conservative temperature envelopes which appropriately bound all MSLB conditions and permitted their use for BWRs and Ice Condenser PWRs.
s We, therefore, recommend the continued use of the previous qualification guidance provided by the interim requirements and a modification to this Regtilatory Guide to assure that its requirements apply to future plants.
As previously stated, this is best accomplished by specifying the Regulatory Guide as a "forward-fit" document.
Comment 9:
As in NUREG-0588 the methods for calculating and establishing containment pressure and temperature should explicitly continue to allow the following:
1.
Utilization of partial revaporization.
11/4/83 37 1AGGAR/A
t 2.
Application of short duration temperature transient in combination with calculation of "skin" temperature calculation to demonstrate adequate equipment performance in transient environments (i.e., not just applica-tion of blanket "soak" temperatures).
Response (Comments 8 and 9):
See response to comment 6 (page 36).
1 11/4/83 38 1AGGAR/A
e e
Section C.4.c Comment 1:
The requirement to assume 50% cesium activity is released instantaneously to the sump is premature.
Until definitive results are available from studies of fission product behavior during post-accident conditions, current assumptions per NUREG 0588 should not be arbitrarily modified, especially on an isotope-by-isotope basis.
NUREG 0771 and NUREG 0772 discuss the issues and summarize the status of studies related to post-accident sources.
It is clear from those documents that the release of cesium is closely tied to that of iodine and that the complex chemistry of the post-accident period will significantly reduce the amounts of cesium and iodine actually released from the pressure vessel.
An ultraconservative assumption such as the instantaneous release of 50% cesium and 50% iodine would significantly increase equipment qualification doses, and would require substantial reanalysis or retesting with no benefit to overall plant safety.
Any revision to current assumptions should only be done on a comprehensive, technically sound basis.
It is quite likely that the effects of increases in radioactive releases of certain chemical species will be offset to a large degree by other factors which affect the time of the release and the distribution inside and outside the primary system.
In addition, this section should clarify the nature of the transport of the halogens to the containment sump.
Comment 2:
Section C.4.c.(1), (2) and (3) discusses the radiation environment for quali-fication of equipment.
The amount of cesium assun.ed released, as a result of the DBA-LOCA, has been increased, primarily based on estimates of releases at TMI-2.
It is noted, however, that the requirement for noble gas and halogen 1
release quantities have noc been decreased as was detected during the same accident.
The arbitrary selection of certain aspects of the THI-2 accident without adequate consideration of all aspects is not technically justifiable.
i 6/16/83 39 2AGGAR/A
Also, in view of the current ongoing research on post-accident source term definition, a change in source terms should not be made at this time.
Comment 3:
The position to include a 50% cesium source term for equipment qualification for LOCAs where the primary pressure boundary cannot be restored is not justi-fiable.
Degraded core rulemaking has not been completed at this time.
There-fore, requiring the inclusion of fission product source terms is inconsistent with current regulatory criteria.
Also, in Appendix C it is stated that source term assumptions may be changed and issued in the final active guide.
It is recommended that any revisions to source term assumptions be subjected to pub-lic review and comment before they appear in an active guide.
In addition, the value and impact has rat been adequately addressed for this i
position.
It it recommended that the final value impact statement address this issue co 71etely if it is retained.
Comment 4:
Tne overly conservative source term characterized in this section is techni-cally insupportable.
It is claimed that, for a LOCA in which the primary system cannot be restored, 50% of the core activity inventory of halogens (i.e., iodine) is instantaneously released from the fuel to the containment.
Also 50% of the cesium inventory is to be assumed to be instantaneously released from the fuel to the primary coolant and carried by the coolant to the containment e. ump. These pathways are not established by experiment or accidei)t experience nor has the "instantaneous" release been observed.
Comment 5:
o We recognize that a value of 50% for cesium may be appropriate based on experience from TMI.
However, we are opposed to incremental changes to the 11/4/83 40 2AGGAR/A
i, source terms over a period of time.
Such an approach cannot be justified on cost-benefit basis.
We strongly recommend that the proposal to increase the cesium content be delayed pending an across-the-board revision of the source term based on TMI.
As a consequence, we recommend deletion of the proposed use of 50% for cesium at this time in the belief that, in the interim, current assumptions contain adequate conservatisms to offset this change.
I l
Comment 6:
This secU on states that 50% of the core activity inventory of halogens should be used for LOCA post-accident source terms.
However, DOE studies indicate the source term should be reduced to one percent or less; NRC Deputy Executive Director for Regional Operations Victor Stello, Jr., agrees that the iodine source is overly conservative; and the director of the Instrumentation and Controls Division for Oak Ridge National Laboratory, F. R. Mynatt, states that only 13 to 17 Curies of the total 2.4 million to 13 million Curies in the TM1 core were released to the environment.
On the basis of these arguments, the 50% core halogen source terms should be revised downward.
Comment 7:
These two sections and Appendix C require that the source term assumption include the release of "50% core inventory of cesium." This requirement shoulti be deleted for the following reason:
l l
Different radionuclides have different release rates.
In addition, the l
chemical form of fission p,roducts released from the fuel is of equal importance to the t.,ercent that is released.
It is therefore inconsistent to assume a release of 50% of the core inventory of lodines and 50% of the core inventory of cesiums without considering the predominant chemical form of the two elements.
6/16/83 41 2AGGAR/A
.=
Comment 8:
Recommend deleting 50 percent core inventory of cesium assumption.
The existing deterministic source terms are still considered adequate to address the total radiation exposure for equipment qualification purposes until further data establishes a need for change.
Different radionuclides have different release rates.
In addition the chemical form of fission products released from the fuel is of equal importance to the percentage that is released.
It is therefore inconsistent to assume a release of 50 percent of the core activity of iodines and 50 percent core activity of cesium without considering the predominant chemical form of iodine.
Comment 9:
Regarding the 50 percent core inventory of cesium assumption, the existing deterministic source terms are still considered adequate when considering the total radiation exposure for equipment qualification purposes until further data establishes a need for change. Different radionuclidos have different release rates.
In addition the chemical form of fission products released from the fuel is of equal importance to the percentage that is released.
It is therefore inconsistent to assume a release of 50 percent of the core activity of iodines and 50 percent core activity of cesium without considering the predominant chemical form or iodine.
Comment 10:
With regard to the "fif ty percent of the core activity inventory of cesium" assumption, we believe the existing source terms are adequate for equipment qualification purposes.
Revision of regulatory requirements concerning fis-sion product source terais should be delayed pending the outcome of the Severe Accident Rulemaking.
6/16/83 42 2AGGAR/A
Comment 11:
These new requirements for radiation doese and dose rate calculations include increasing the Cesium release fraction ts 50% and using mechanistic assumptions for radioactivity distribution, time-dependent transport, and plateout.
These requirements would require the recalculation of all radiation source terms used for equi,ement qualification. These changes are not required for safety.
The existing use of TID 14844 source terms is extremely conservative.
TID 14844 source terms far exceed the radioactivity release fractions deter-mined from 10 CFR 50 Appendix K ECCS evaluation model analysis for design-basis accidents. The new radiation source terms are also not consistent with the source terms required by NUREG-0578 or NUREG-0737.
It is recommended that this section be rewritten to allow the use of TID 14844 source terms.
The suggested changes should not be implemented unless the planned Severe Accident Rulemaking or further research demonstrates a need for such changes.
Comment 12:
Position C.4.c. does not reflect current industry thinking on the selection of source terms and the calculation of radiation dose rates for equipment quali-fication.
The addition of 50% cesium to the source term reflects a narrow view of the problem.
There is no evidence that the overall radiation source term or cal-culated radiation doses are not conservative.
In fact, the existing source terms and doses are generally accepted as being extremely conservative.
When the overall source term and dose rate are still conservative, there is no justi-fication for modifying one small part of the source term.
Such modification can only result in having a significant impact on the plants who must now reassess their radiation calculations and the qualification of their equipment while providing no increase in safety.
The 50% cesium portion of the source term should be delated from this regulatory guide.
6/16/83 43 2AGGAR/A
4
?
Comment 13:
The NRC has initiated a number of rulemakings thich include an examination of fission product source terms.
It is anticipated that an integrated decision on a significant amount of fission product research and analysis will result from these rulemakings in the relatively near future.
In addition, questions on the release and transport of fission products at TMI have become the focus of significant industry and regulatory research. We expect this work to con-tribute to the development of a more coherent, integrated technical basis that will better define the need for and content of any proposed requirements involving equipment qualification for fission products.
In our judgement, it is inconsistent for the NRC to implement particular aspects, e.g., fission product phenomena of the TMI accident, on a piecemeal basis while the NRC has ongoing a generic rulemaking to determine the extent to which degraded cores should be treated in the regulatory process.
It is also inconsistent for the NRC to modify a particular aspect of the current deterministic DBA source term to reflect only one of THI's observed mecha-nistic events.
The urgency regarding public safety for this proposed change is not apparent given that TMI demonstrated that the current regulatory assumptions regarding fission product transport and consequences analysis may more than compensate for any increased fission product concentration in the containment recircula-tion systems.
Therefore, the revision of any regulatory requirements involving fission product source terms should be delayed pending the outcome of the Severe Accident Rulemaking.
Comment 14:
We maintain that the use of the existing equipment radiation qualification doses, based on TID-14844 source terms, and developed using conservative release and removal assumptions provides significant confidence in safety-related electrical equipment's ability to withstand the radiation stresses imposed by DBE LOCA's and also provides sufficienL confidence of such 11/4/83 44 2AGGAR/A
s' capability for severe degraded core events. Therefore, the adjustment by the Staff of the existing equipment qualification source terms to envelope an assumed release fraction of Cesium is unwarranted; provides no additional confidence in that equipment's capability for DBE LOCA's and will not substantively change the encompassed percentage of degraded core events during which this equipment
.can function.
We recommend deleti.g the 50% Cesium source terms fro;a Sections C.4.c(1),
C.4.c(2) and from the calculations in Appendix C.
Comment 15:
The equipment qualification source terms presently used and based on TID-14844 are indicative of hypothesized core damage well in excess of that calculated using 10 CFR 50 Appendix K licensing models.
The use of these TID-14844 source terms have provided extremely large radiation dose margins for safety-related equipment required to function to limit core damage within the design basis LOCA (Appendix K) limits.
These margins also justify such equipment's capa-bility to operate during hypothesized accident sequences which fall well out-side the bounds of the Appendix K analysis (degraded core events).
Comment 16:
Consideration of a 50 percent cesium source term significantly deviates from previous regulatory guidance and will substantially increase doses to equip-ment near the coetainment sump which are required to operate for extended post-accident perleds.
Given the prospect of a Severe Accider.t Rulemaking by the NRC, present studies and research efforts underway by both NRC and indJs-trj, and the significant impact of this change, it is premature to require consideration of any source terms additional to those addressed heretofore in plant design.
All considerition of degraded core events beyond current plant design bases should be relegated to generic rulemakings where such events can be adequately addressed in an integrated fashion.
A piecemeal approach may 6/16/83 45 2AGGAR/A
\\
. result in overly conservative source terms, resulting in high costs for operating plants if previously acceptable equipment is required to be replaced.
Also, the value impact statement does.not reflect the significant impact this change in source terms will have on operating plants.
Comment 17:
The proposed requirement to include 50% of the core activity inventory of cesium based on the fact that THI-2 experience lacks similar reductions in the assumptions for noble gas and iodine releases, is premature, and would impose greater radiation dose qualification requirements than those which actually may be needed.
Appendix C of the proposed Regulatory Guide states:
... as a first step towards modification of the TID-14844 source term... it may be prudent to include a cesium release in addition to the previously assumed '1% solids'."
This statement implies that there will be additional steps toward modifying the TID-14844 source terms.
The proposed guide further states that:
"The assumed cesium release implies no substantial departure from, and is consis-tent with, the degraded core conditions previously implied by the assumed release of 50% of the core todine activity." This can be interpreted to indi-cate that our past accident analyses which are based on TID-14844 source terms may be subject to change since the fundamental assumptions contained in TID-14844 do not include special release fractions for cesium.
The proposed revision to Regulatory Guide 1.89 concerning the rac.'ation source term should await the conclusions from the report contained in NUREG-0772.
Comment 18:
Delete the 50% Cesium source term from Items C.4.c(1), C.A.c(2) and from the calculations performed in Appendix C.
6/16/83 46 2AGGAR/A
e Comment 19:
We recommend deleting the assumption that 50 percent core inventory of cesium is related to Primary Containment.
The existing deterministic source terms are still considered adequate to address th,e total radiation exposure for equipment qualification purposes until further data establish a need for change.
Different radionuclides have different release rates.
In addition, the chemical form of fission products released from the fuel is of equal importance to the percentage that is released.
It is therefore inconsistent to assume a release of 50 percent of the core activity of iodines and 50 per-cent core activity of cesium without considering the predominant chemical form of iodine.
Response (Comments 1 thru 19):
The staff agrees with these comments.
The staff has revised the source terms of Regulatory Position (4.C.(1)) to incorporate the previous guidance con-tained in NUREG-0588 and the DOR Guidelines and to remove the proposed addi-tional cesium source term.
The staff acknowledges that additional research efforts are underway which may lead to revisions in the source terms proposed for equipment qualification.
The research will consider the experience from the Three Mile Island accident, contemporary fission product release phenomenology, considerations of the transport and attenuation of fission products in primary coolant systems and containments, and distinctions between design basis accidents and beyond design basis events.
The staff believes that an equipment qualification envelope which uses source terms contained in revised position 4.C.(1) (i.e., TID-14844 source terms) coupled with the conservative assumptions contained in Appendix D to this guide provide assurance that el*ctric equipment important to safety can with-stand the radiation environments associated with design basis LOCAs as well as some accidents which could be categorized as beyond current design bases.
11/4/83 47 2AGGAR/A I
Comment 20 The assumption of "instantaneous" fuel-to-coolant release of fission products is unrealistic and non-mechanistic, and therefore inconsistent with the subse-quent mechanistic treatment of radionuclide transport, distribution and removal.
Radionuclide releases from the fuel should be based on time-dependent models or, alternatively, a time-delay release assumption should be added, as is pro-vided for the DBA-LOCA "with restoration" in Section C.4.c(1).(b).
Comment 21:
We recommend removing the instantaneous release assumptions, and substituting a conservative time delay release consistent with available knowledge which is on the order of 10 minutes.
The current NRC assumption of instantaneous release of radionuclides from the core coincident with the start of an acci-dent is unrealistic.
It is not based on consideration of any physical mechanisms.
Comment 22:
The assumption of instantaneous release of radionuclides from the core coinci-dent with the start of an accident is unrealistic as it does not consider any physical mechanism.
To release the majority of the radionuclides contained in the core instantaneously, the core would have to begin to melt instantaneously.
There should be a time delay applied to the release which takes into considera-tion the physical mechanisms associated with a core meltdown.
Comment 23:
The assumption of instantaneous release of radionuclides from the core coinci-dent with the start of an accident is unrealistic as it is not based on con-sideration of any physical mechanisms.
The core cannot begin to melt, and thus release the bulk of its contained radionuclide inventory, for a time 6/16/83 48 2AGGAR/A
t 9
period of at least 10 minutes under worst case accident scenarios.
And even as the core meltdown begins, all radionuclides would not be released at once, but rather, would be released over some extended period of time.
Therefore, the release assumptions in this Reg Guide should reflect the known sequence of iodine spiking gap release followed by meltdown, vaporization and oxidation fractions.
Comment 24:
The requirement to assume an instantaneous release is unrealistic.
The NRC should permit the applicant to justify a time-dependent release tr the primary system.
Comment 25:
Recommend substituting instantaneous release assumptions with a conservative time delay release consistent with available knowledge which is on the order L
of 10 minutes.
Comment 26:
The required instantaneous release assumption of Position C.3.c.(1)(a) is not justified for the qualification of Class IE equipment.
The use of a delayed release should be acceptable when justified.
Comment 27:
Regulatory Position C.4.c.(1)(a) requires the assumption of instantaneously releasing radiation sources into the containment for a LOCA.
This has the effect of unrealistically high initial peak radiation.
To substantially aggra-vate the. assessment of equipment's ability to withstand peak radiation dose rate.
Most prescat day qualification programs pay little heed to dose rate 6/16/83 49 2AGGAR/A
8 except in respect to the rate dependent accumulative aging effects.
The subject of concern here, however, is the effect of peak radiation immediately.
on the operability of certain equipment.
Comment 28:
Sections C.4.c.(1),(2) require the use of an "instantaneous release" assump-tion.
This assumption is unrealistic since it is not based on current knowl-edge (WASH-1400, for example).
WASH-1400 provides evidence to support the following statements:
1.
The core cannot begin to melt, and, thus, release the bulk of its con-tained radionuclide inventory, for a time period of at least, on the order of, 10 minutes, under the worst case scenario.
2.
Even as the core meltdown begins all radionuclides would not be released at once and at some point in time, but, rather, would be released over some extended period of time.
Release assumptions should reflect the known sequence of iodine spiking GAP release followed by meltdown, vapori-zation and oxidation fractions.
Comment 29:
We question the assumption of instantaneous release.
The guide should recom-mend a specific time delay.
Comment 30:
The instantaneous releases described in the source term discussions are too conservative and imply dose rates (from Tables C-1 and C-2) that are incredible and can't be achieved in testing.
A more realistic approach is needed.
6/16/83 50 2AGGAR/A
c c
Comment 31:
Instantaneous releases to the containment are too conservative and lead to a testing dilemma of implied dose rates.
Tables C-1 and C-2 show initial rates in excess of 4 MR/h (gamma) and 23 MR/hr (beta).
These are incredible and can't generally be met in testing.
I suggest a mechanistic, realistic approach, perhaps such as outlined in NUREG/CR-2367, "Updated Best-Estimate LOCA Radiation Signature."
Other considerations in this paragraph include:
(1) equilibrium core inventory?
(2) distribution of fission products in containment?
Response (Comments 20 thru 31):
The staff agrees that the instantaneous release assumption is very conservative.
The staff notes that additional research is occurring in the area of fission product release as a function of temperature and that a time-dependent fission product release model may be developed.
Until the staff studies are completed, the staff intends to retain its conservative position on "instantaneous" release.
Comment 32:
In Section C.4.c the NRC position requires that accident environment conditions be assumed to occur "at the most critical point of degradation during the installed life... which may be the end of the installed life." The implication is that industry must justify when in the life of the equipment it is most vulnerable to the environment, which may be but may not necessarily be the end of installed life.
Such an approach could require extensive justification to pinpoint the worse case time. We recommend that this section be revised to include the assumption that all events generating adverse environments are 11/4/83 51 2AGGAR/A
4' r
assumed to occur at the end of the installed life of a device.
This'is considered conservative, as all materials are known to degrade with time.
Comment 33:
We believe that, in the absence of information to the contrary, it is reason-able to assume that equipment will not improve with age and, therefore, that the critical point of degradation is at the end of the equipment's qualified life.
Thus, we recommend that the second sentence be revised to read:
"In the absence of information which might indicate that the equipments per-formance can improve with age, it should be assumed for qualification purposes that the accident related environmental conditions occur at the end of the qualified li S of the equipment."
Comment 34:
The intent of the second sentence (Section C.4.c) "It should be assumed that
... installed life." is not clear.
It is suggested that this sentence be clarified or relocated to the section discussing determination of qualified l
life.
Response (Comments 32 thru 34):
l In choosing the wording of the draft position, the staff was not concerned with improvement of equipment with age, but with the possibility that a piece
(
of equipment could be more susceptible to radiation failure early in its life-time.
In the absence of information which would suggest that this is a prob-l lem, the staff has rewritten the statement for clarity.
6/16/83 52 2AGGAR/A l
n s
Comment 35:
The assumption (Section C.4.c.(2)) that all the gaseous constituents be released to the primary coolant is not technically justifiable. Only a portion of the gaseous activity would remain in the coolant, the remainder would accumulate in vapor spaces inside the vessel, pressurizer, and piping. A more appropriate assumption would be that the activity is released to the primary system.
It would then be distributed according to physical laws rather than by regulatory prescription.
The assumption of a 50% cesium release to the primary coolant should await a comprehensive, technically sound evaluation of source term requirements.
Response
The staff agrees with this comment and has revised the regulatory position on source term.
See response to Comments 1 through 19 (page 47) for the resolution of the source term and cesium comment.
Comment 36:
The increase in the assumed cesium release from the core from the previous 1%
of the core inventory to the proposed 50% of the core inventory will adversely impact the equipment qualification for much equipment required to operate in the long term following an accident.
Although the increase in dose resulting from this change depends on factors such as the operating time, the amount of shielding between the source and the piece of equipment, and the nature of the source, preliminary calculations have shown up to an approximately factor of eight increase in dose to certain pieces of equipment.
Equipment already installed may not have been tested to this dose, and equipment yet to be tested may not survive such an exposure.
Therefore, careful consideration should.be given to the potential effect the adoption of this rule would have.
For example, the chemical form of the cesium should be considered, as well as 11/4/83 53 2AGGAR/A
2 the fact that some of the technical studies used to justify the 50% cesium release indicate that a reduction in the assumed iodine release might also be appropriate.
Response
The staff agrees.
Also, see Response to Comments 1 through 19 (page 47).
Comment 37:
Radiation environment normally expected over the installed life is interpreted as the radiation source terms (failed fuel) associated with normal operation and used to estimate the effluent releases per Regulatory Guide 1.112.
A design basis value of 1 percent failed fuel is not normally expected over the installed life. We suggest that a clarification or additional information be provided so that interpretation is not required.
Response
In past versions of this regulatory guide, the staff did not provide guidance for sour.ce terms to be used in establishing the radiation environment result-ing from normal operation.
Additional guidance on this topic has been provided in Appendix D to this regulatory guide (see Appendix D, Section 2.1).
Comment 38:
Recommend changing the term "most severe accident" to design basis accident (Section C 4.c).
The latter is the more commonly used term.
The first sentence should be changed by substituting the term "design basis accident" for "most severe accident." This would maintain consistency with terminology commonly used in this and other qualification documents.
11/4/83 54 2AGGAR/A
-o-
Response
The staff agrees.
The Regulatory Position C 4.c has been modified.
Comment 39:
This section (C.4.c(8)(a) states that gamma and beta doses to equipment should be considered.
C.4.d(5)(h) goes on to state that Co-60 or Cs-137 are acceptable gamma sources for environmental qualification; guidance _should also be provided on acceptable beta sources.
Response
As part of the ongoing research effort at Sandia, the NRC is presently studying the problem of simulation of radiation environments for equipment qualifica-tion.
This research is addressing the adequacy of gamma radiation to simulate the radiation damage associated with a significant beta radiation environment.
Following the conclusion of this work, the staff will be in a better position to formulate changes in the beta qualification methods and revise the regula-tory positions, if appropriate.
Comment 40:
For PWRs we recommend that this source term not be applied to all systems out-side of containment de facto.
Rather, the analyses should be based on the particular plant emergency procedures and intended use of auxiliary systems like the RHR.
For example, at TMI the RHR was never used and if such a com-mitment is made by the utility, qualification to a source term equal to a "restorable" LOCA is unjustified.
Response
Revised Position C.4.c(8) describes the staff position regarding equipment located outside containment and addresses this comment.
6/16/83 55 2AGGAR/A
e s
Coment 41:
We can find no technical basis for a difference in the time delay to fuel failure and subsequent release of activity between the recoverable and non-recoverable LOCA.
Fuel damage will not occur instantaneously in either event.
A clarification of the basis for the time factor should be included to assist in understanding this regulatory position.
Response
The staff agrees with the coment.
Regulatory Position C.4.c(1) has been rewritten to reflect previous source term guidance contained in NUREG-0588 and the 00R Guidelines. The revised position states that instantaneous fission product releases should be assumed for conservatism.
See response to Coment 20 through 31 (page 51) for a discussion on the use of "instantaneous" release assumptions.
Comment 42:
The requirement to consider a "restorable" LOCA on a BWR should be technically justified.
If the NRC believes that a BWR LOCA can occur which causes gross fuel damage and is isolatable, than a mechanistic scenario should be provided to rationalize the event and provide a basis for quantification and distribu-tion of sources into affected systems.
There is no obvious scenario for a BWR which could lead to the radioactivity source conditions required by this item.
i
Response
See response to Coment 41 above.
l 6/16/83 56 2AGGAR/A
4' s
Comment 43:
The last two sentences in this paragraph (C.4.c(2)), starting on page 6 with the words "When fuel melting is postulated..." and ending on page 7 with the words "... released to the primary coolant." should be deleted.
This goes way beyond NUREG-0737 and represents a substantive unjustified increase in equiva-lent qualification source terms.
Response
The staff disagrees that this position represents a substantive unjustified increase in equivalent qualification source terms.
In fact, the staff believes this position represents a relaxation of the source term requirement for non-LOCA accidents.
The guidance in Item II.B.2 of NUREG-0737 assumed that 100%
of the fuel cladding failed and released all the gap activity to the primary system.
This is very conservative for most cases.
Position C.4.c(2), which is consistent with present licensing reviews for chapter 15 of SARs, permits licensees to estimate the fraction of fuel which could experience failure and then establish qualification requirements based upon the calculated failed fuel fraction, instead of assuming complete core failure.
The requirement to include the melted fuel fraction is consistent with licensing practice for such SAR design basis accidents as rod ejection, main steam line break or locked reactor coolant pump rotor.
Comment 44:
Define system depressurization in paragraph C.4.c.(1)(b).
A conservatively long time might be the 36-hour limit of Regulatory Guide 1.139, or other plant specific commitment. No degasification should be assumed unless a licensee com-mitment is made, and the off gas should be assumed held up inside containment, 6/16/83 57 2AGGAR/A
Response
Position C.4.c.(1) has been revised to reflect the previous guidance contained in NUREG-0588 and the DOR Guidelines.
References to the two proposed types of design basis accidents have been removed.
See Response to Comment 41 (page 56).
Comment 45:
Section C.4.c should also address how shine from the BWR refueling floor airborne activity will be treated with respect to equipment qualification in a radiation environment.
Response
While the comment is not specific in its statement of concern, the answer is fairly simple.
Section 1 of Appendix 0 states that the radiation environment should be based upon three major types of source terms distributions.
It con-tinues that a piece of equipment may receive a contribution from any or all of thue sources.
Therefore, the refueling floor airborne activity should be included in the radiation environment for am piece of equipment for which that airborne activity is a contributor.
Comment 46 This section specifies that, for a limited unspecified number of accident monitoring instrumentation channels with extended ranges, the source term should assume an initial release to the containment that considers the fission product release groups associated with grossly melted fuel.
This conflicts with the provisions of Regulatory Guide 1.97, which specifies that "Instrumen-tation whose ranges are required to extend beyond those ranges calculated in the most severe design basis accident event for a given variable should be qualifted using the guidance provided in Paragraph 6.3.6 of ANS-4.5".
Para-graph 6.J.6 of ANS-4.5 specifies in part that "All environmental envelopes
]
except that pertaining to the variable measured by the information display 6/16/83 58 2AGGAR/A
4 channel shall be those associated with the design basis accident events".
Footnote 3 to this sentence should also be noted.
It states that "Since Type C variable ranges are non mechanistically determined, extension of asso-ciated parameter levels is not justifiable and has therefore not been required".
From the foregoing, we conclude that it is inappropriate to require considera-tion of fission products release groups associated with grossly melted fuel, since the latter is not currently a design basis event for operating plants.
The qualification environment for instrumentation associated with extended range variables should be based on design basis accident events, except the assumed maximum of the value of the monitored variable shoulc be the value equal to the maximum range for the variable. This is in accord with Regulatory Guide 1.97, which endorses ANSI /ANS-4.5-1980 in this area.
This proposed section should therefore be deleted.
Comment 47:
Contrary to the statements made in this Section, Regulatory Guide 1.97 "Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident," and NUREG-0737, "Clarification of TMI Action Plan Requirements," require qualification of the high range containment radiation monitors to an assumed rad per hvor value which then decays at a rate proportional to the decay rate expected for a LOCA, as opposed to using a particular source term as indicated in this Section.
Additionally, ANSI /ANS-4.5 1980, "American National Standard Criteria for Accident Monitoring Functions in Light-Water-Cooled Reactors,"
requires qualification to DBE conditions for all parameters except the moni-tored variable which should be to the extended range level with no additional margin.
We, therefore, recommend that the first sentence be changed to read as follows:
"For a limited number of accident-monitoring instrumentation channels with instrument ranges that extend well beyond the values the selected variables can attain under limiting conditions as specified in Regulatory Guide 1.97, the source term should be consistent with Position C.1.3.la of Regulatory Guide 1.97, "Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Fol-lowing an Accident." The remainder of this Section should be deleted.
6/16/83 59 2AGGAR/A
.i P
Comment 48:
Recommend revising the first sentence to read as follows:
"(3) For a limited number of accident-monitoring instrumentation channels with instrument ranges that extend well beyond the values the selected variables can attain under limiting conditions as specified by the plant specific implementation of the guidance provided in Regulatory Guide 1.97....".
The limited number of instru-ments considered to be addressed by this section, and their ranges should be clearly specified by the plant specific implementation of the guidance pro-vided in R.G. 1.97 to eliminate possible extension of this requirement to other instruments. The intent of this section should be to define the source terms to be used in qualification and not to define the equipment to be qualified.
i Comment 49:
A source term associated with grossly melted fuel is only applicable to the qualification of instrumentation which monitor extended range radiological parameters (Reference Regulatury Guide 1.97, position 1.3.1, and ANS 4.5, paragraph 6.3.6).
The environmental qualification to accident radiation conditions should be based on design basis events for instrumentation which monitor nonradiological parameters.
The independence of an extended range parameter from other qualification parameters must be clarified.
Comment 50:
[
The limited number of instruments and their ranges should be clearly specified in the plant specific implementation of R.G. 1.97, not R.G. 1.89.
The intent of this section is to define the source term to be used in qualification of equipment, not to define the equipment to be qualified, t
11/4/83 60 2AGGAR/A i
c.
l Comment 51:
The assumption of 100% release of Te to the containment stated in this section is quite inappropriate.
It is known that Te plates out on the walls of vessels and would be appreciably retained in the primary containment system (Ref:
j Allison, G.
M., "Release of Fission Products from 002 Fuel Failures in Loops at Chalk River", AECL Report CEI-170, June 1965).
I Comment 52:
More specific guidance is needed on the mechanistic model to be used with this new source term.
Is what is outlined in NUREG/CR-2367, "Updated Best-Estimate LOCA Radiation Signature," August 1981, the intent of the Guide?
If so, this report should be referenced.
Response (Comment 46 thru 52):
The staff agrees with these comments.
Position C.4.c(3) has been modified to reflect the qualification guidance provided by Position C.1.3.la of Regulatory Guide 1.97, Revision 2 (December, 1980).
Comment 53:
Delete paragraphs C.4.c(4), (5), (6) and (7) from Section C and place them into the Appendix D sample calculation and methodology description.
Response
In general, the staff agrees with this recommendation.
While Position C 4.c(4) has been retained as a regulatory position, Positions C.4.c(5), (6) and (7) have been deleted and, accordingly, the information has been placed in Appendix D to this guide.
11/4/83 61 2AGGAR/A
?
?
Comment 54:
Using Appendix 0 and the ratio of PWR/BWR free "containment" volumes will result in extremely large doses and dose rates.
Response
The staff agrees with this comment. The staff has taken a conservative approach.
Comment 55:
Section C.4.c(6) states that the effects of ESF systems that act to remove airborne activity and redistribute activity within the containment should be calculated using the same assumptions used in calculating offsite doses.
This section should be modified to allow the designer to make plant specific assump-tions on the status of these ESF systems, depending on the location of the piece of equipment under analysis.
Response
The staff disagrees with this recommendation.
The intent of this position was to provide guidance for judging the effectiveness of the operating engineered safety features systems in defining a radiation environment, and not on the status of those systems.
However, it should be noted that this position has been removed from the list of regulatory positions and placed in the method-ology discussion in Appendix D to this guide.
The staff concludes that this i
change provides more flexibility for plant specific assumptions.
Comment 56:
l The removal of iodine from the containment atmosphere cannot be accurately determined until a realistic determination is made of the chemical form of the 11/4/83 62 2AGGAR/A
o t
released fission products.
In particular, if Csl is postulated as the pre-dominant form of the iodine released durin0 an accident, then acceptable assumptions should be provided to account for the rapid redistribution of the airborne iodine to the containment ' mp or suppression pool.
The proposed release of 50 percent of the core cssium activity inventory is incomplete and not recommended without addressing the interaction mechanisms of such a release with the iodine source term.
Comment 57:
Paragraph C.4.c.(6) states the effects of ESF systems to remove airborne activity should be calculated using the same assumptions used to calculate offsite doses in SRP 15.6.5 (i.e., 50 percent plateout).
However, paragraph C.4.c.(7) states that the assumption of 50 percent instantaneous plateout should not be made.
This conflict should be resolved.
Comment 58:
These two paragraphs (C.4.c.(6) and C 4.c.(7) on removal of airborne activity mix mechanistic, best estimate assumptions with conservative, offsite dose assessment assumptions in a conflicting manner.
Response (Comment 56 thru 58):
The staff agrees with these comments.
Additional work is underway to provide more insight into the magnitude of and chemical form of radiofission products released following accidents.
As this information becomes available, it will be factored into the overall equipment qualification program, i
Even though these positions have been removed and hive been relocated to the methodology discussion in Appendix 0 to the guide, the staff emphasizes that the radiation qualification environment should be based upon the actual capa-
.bilities of ttue plant's engineered safety features.
11.'4/83 63 2AGGAR/A
Comment 59:
The plateout model of 50% of the iodine as outlined in the current NRC guidance NUREG/CR-0009 is inconsistent with the experience at TMI-2 where less than 1% of the iodine has been observed to plateout.
These models should be updated to recognize that iodine will not transport to surfaces outside the i
reactor coolant system as I -
2 Comment 60:
No basis is provided for distallowing the "assumption of 50 percent instanta-neous plateJut of the iodine released from the core." A basis should be provided.
Comment 61:
In paragraph C.4.c.(7), the parenthetical expression "(see Re*. 3 Appendix C)."
The cited te ;rence does not represent a mechanistic model and best estimates for the model parameters.
1 Response (Comment 59 thru 61):
The staff recognizes that the models for estimating iodine plateout currently contained in NUREG/CR-0009 are conservative.
Further, the source term issue will be dealt with as part of the present staff research program.
As a result, i
the staff will not introduce new methods or models at this time.
However, this position has been removed from the list of regulatory positions and placed in the methodology discussion in Appendix 0 to this guide.
11/4/83 64 2AGGAR/A
g.
O.
Comment 62:
This paragraph should be reworded and appended to Section C. Item C.4.c.(8) which would read in parts as follows:
Safety-related electrical equipment which could be exposed to a hostile accident radiation environment must be environmentally qualified to a radiation dose that simulates the conservatively calculated radiation environment that the equipment should withstand prior to completion of its required safety function.
Such qualification must consider that equipment damage is typically a function of total integrated dose only, but may be influenced by dose rate, spectrum and particle type.
The qualification dose should be the sum of the calculated doses of the potential radiation sources at the equipment location (i.e., beta and gamma). Plant-specific analysis may be used to justify any reduction in dose or dose rate due to the specific location or shielding.
Response
In general, the staff concurs with this recommendation. Revised Position C.4.c.(5) incorporates some of the stiggested wording.
Comment 63:
The sum of beta and gamma doses (and implied rates) is probably more severe than technically justified.
Sandia is just beginning to look into that assumption in the QTE Program.
Because of the hypothetical approach in Appendix 0, the dose rates are Jo high that to determine whether similar damage is produced will be very difficult.
11/4/83 65 2AGGAR/A
Comment 64:
Oslete the section C.4.c.(8).
The introduction of a beta dose criteria demands additional consideration of its overall significance in the qualifica-tion program prior to inclusion.
Comment 65:
The qualification dose should not be the sum of the calculated doses of potential radiation sources at the equipment location (i.e., beta and gamma).
Beta and gamma doses are not additive.
The effects of the beta radiation are limited to surface effects.
Comment 66:
In general, the aging and accident radiation cannot be combined and their combination should not be endorsed.
Some reasons are that:
(1) dose rates are drastically different, (2) particle types are drastically different, (3) equipment functionability must be monitored during accident radiation simulation since that radiation is an accident environment.
Comment 67:
The demand for "equivalent" energy deposition rate will absolutely shut down the industry.
Appendix E implies a dose rate in excess of 20 MR/hr, which is not achievable, i
These high rates result from hypothetical, instantaneous, release assumptions which could be avoided if a mechanistic-release approach is taken, such as that outlined in SAND 79-2143, "Best-Estimate LOCA Radiation Signature."
f 9
J 11/4/83 66 2AGGAR/A e
o' F
Response (Comment 63 thru 67):
The staff recognizes that radiation qualification based upon the sum of the total beta and gamma doses is conservative.
The wording of revised Position C.4.c(5) removes the previous requirement to sum the doses, but does not remove the requirement to consider the potential radiation damage from beta radiation or other radiation types.
The staff expects that the revised word-ing will lead to the licensee's evaluation of the inherent shielding potential of equipment for beta sensitive components.
At the same time the staff believes that summing the beta and gamma accident doses would still serve as a valuable first order approximation for establishing the qualification envelope for the maximally exposed equipment.
Revised Position C.4.c(6) offers some additional guidance concerning the importance of gamma and beta radiation doses for qualification envelopes.
Comment 68:
The NRC generally endorses the calculation of beta doses within the containment using an infinite cloud model and using that value for equipment qualification.
This simplistic model may yield reasonably accurate values for the beta dose in air at the containment centerline.
In fact, industry calculated results generally agree rather well with those of the NRC.
This approach overesti-i mates the dose to an actual piece of equipment.
For equipmer.c qualification, it is inappropriate to use the sum of free-air beta and ga'nma contributions as stated in several HRC references.
The proper equipment qua
%ation dose is a good deal lower than the sum of the free-air beta and gams contributions.
Due to the quite short rarge of beta particles in typical materials comprising a piece of equipment, it can be shown that:
the geometry appropriate for beta dose calculation is usually, at most, a semiinfinite, and often a finite cloud even for quite small pieces of equipment, such as cable.
This is due to self-shielding effects of the equipment and the effects of enclosed spaces around
.the equipment.
The majority of the equipment has sufficiently thick coverings around any radiation sensitive components of materials so as to reduce the 6/16/83 67 2AGGAR/A
9 beta contribution to the. total dose to a level far below that (less than 10%)
of the gamma contribution.
Proper attention to the above considerations will, in most cases, render the beta dose probles a nonproblem when compared to the magnitude of the concomi-tant gamma dose.
Comment 69:
Beta dose to equipment, particularly internal components sensitive to radia-tion, is often insignificant compared with the concomitant gamma dose, when more realistic modeling is applied to account for the shielding effects of the equipment enclosure.
Therefore, we believe this section should state that:
"... where it can be shown by analysis that the beta dose to the equipment is less than 10 percent of the associated gamma dose, it is sufficient to use gamma dose only for equipment qualification purposes."
Comment 70:
i Recommend adding a sentence after first sentence as follows:
Where it can be shown by analysis that the beta doses to the equipment is less than 10 percent of the associated gamma dose, it is sufficient to use gamma dose only for equipment qualification purposes.
Beta dose to equipment, particularly internal components sensitive to radiation, J
is often insignificant compared with the concomitant gamma dose, when more realistic modeling is applied to account for the shielding effects of the equipment enclosure.
l Comment 71:
i l
Delete the requirement for use of the sum of the calculated beta and gamma f
doses for equipment qualification purposes.
Instead, substitute the following:
6/16/83 68 2AGGAR/A i
t
"Where it can be shown by analysis that the beta dose to the equipment is less than 10% of the associated gamma dose, it is sufficient to use gamma dose only for equipment purposes."
Add the follow'ng sentence to Section C.4.c.(9):
"Use the infinite or semi-infinite cicud models where applicable in the analysis that is performeri to show that the beta dose to the equipment is less than 10% of the associated gamma dose."
Comment 72:
This now reads, "the qualificati-.a dose should be the sum of the calculated doses of the potential radiation sources at the equipment location (i.e., beta and gamma)." This is misleading in light of the following sections (e.g.,
C.4.c.(9)) which allow recognition of the fact that sensitive portions of com-ponents may be shielded from beta radiation exposure.
A better wording might then be:
"the qualification dose should combine contributions from potential sources of both gamma and beta radiation, considering possible shielding of sensitive compo.ents from the latter."
Response (Comment 68 thru 72):
In general, the staff agrees with these comments.
Former Position C.4.c.(9) has been modified to incorporate some of these comments and is now revised Position C.4.c.(6).
Also see response to Comments 63-67 (page 67) concerning the sum of beta and gamma doses.
Comment 73:
This sentence should be revised to read as follows:
"Class 1E equipment located outside containment that is ~< posed to Ene radia-tion from recirculating fluid and that must perform a safety function following the accident should be qualified.
6/16/83 69 2AGGAR/A
Response
The staff agrees with this comment and revised position C.4.c(8) incorporates the suggested wording.
Comment 74:
This section states that "Equipment that may be exposed to low level radiation doses should not generally be considered to be exempt from radiation qualifi-cation testing.
Exemption may be based on qualification by analysis supported by test data or operating experience that verifies that the dose and dose rates will not degrade the operability of the equipment below acceptable values "
This regulatory position should be revised to explicitly exempt organic materials from radiation qualification when located in 3reas with maximum radiation levels of 104 rads or less.
Comment 75:
Recommend deleting paragraph and replacing with the following:
"In general, equipment located in areas where the total integrated gamma doses including post accident doses do not exceed 105 Rads are exempt from he requirements to demonstrate qualification by analysis or testing.
For solid state electronic devices this threshold dose below which they are exempt from qualification testing or analysis is 103 Rads gamma."
A radiation threshold dose level should be established below which equipment can be considered exempt from demonstration of its capabilities by testing /
analysis.
Plastics and elastomers are used in power plant equipment in the form of gaikets, insulation, jackets, 0-Rings, seals, hoses, diaphragms, supports, and filler materials. Review of available data on various commonly used plastics and elastomers used in the construction of the safety related 6/16/83 70 2AGGAR/A l
4 electrical and instrumentation equipment shows that they have a threshold damage radiation dose level of 10s Rads or above.
The exceptions are poly-tetra flouroethelyne or teflon (1 x 105 Rads) and polysulphide rubber (8 x 105 Rads), and some solid state electronic devices (less than 104 Rads).
Lubri-cants and greases used in safety related electrical equipment have a threshold damage integrated radiation dose level of 108 Rads or higher.
A common design engineering practice used in the industry is to require exclusion of materials known to be particularly susceptible to radiation by equipment design specifi-cations and assure the same through the vendor drawing / document review process.
Comment 76:
The use of a threshold of 105 rads, below which no qualification testing is necessary, should be acceptable.
Comment 77:
Qualification to radiation environments below 103 rad is not warranted for equipment qualification purposes and equipment exposed to such low-level doses should be exempt from radiation qualification testing.
Comme;nt 78:
This section should be revised to read as follows:
"Equipment that may be exposed to low-level radiation doses can be considered exempt from radiation qualification testing if analysis supported by test data or operating experience verifies the dose and dose rates will not degrade the operability of the equipment below acceptable values."
6/16/83 71 2AGGAR/A
e s
t 4
+
i Comment 79:
Equipment that may be exposed to integrated doses less than 104 rads should be exempt from qualification unless a specific component is judged to bt excep-tionally radiosensitive, in.which case, such equipment should be qualified :y.
analysis'or test data on a case-by-case basis.
Comment 80:
Section 8 discusses the numerous studies which show that for all classes of organic compounds the radiation damage threshold is greater than 104 rads.
This Section does not allow for any exemptions and thus disregards Section B.
Change this Section to read:
"Nonelectronic equipment which is subjected to less than 105 rads total integrated dose is exempt from qualification analysis or testing.
Likewise, electronic equipment which is subjected to less than 103 rads total integrated dose is excluded."
Comment 81:
Equipment exposed to low-level radiation doses should be excluded from consider-atior for radiation qualification.
A radiation threshold dose level should be established below which equipment can be considered exempt from de stration of its capabilities by testing / analysis Plastics and 21astomers are used in power plant equipment in the form of gaskets, insulation, jackets, 0-Rings, seals, hoses, diaphragms, supports, and filler materials.
Such materials generally have a threshold damage radiation dose level of 108 Rads or above.
The exceptions are polytetra flouroethelyne or teflon (1 x 105 Rads) and poly-sulphide rubber (8 x 105 Rads), and some solid state electronic devices (less than 104 Rads).
Therefore, we recommend that this section state that:
"... equipment located in areas where the total integrated gamma doses includ-ing post accident doses do not exceed 105 Rads are exempt from the requirements to demonstr4te qualification by analysis or testing.
For solid state elec-tronic devices this threshold dose below which they are exempt from qualifica-tion testing or analysis is 103 Rads gamma."
6/10/83 72 2AGGAR/A
s Comment 82:
I' agree with this paragraph, but it seems to conflict with Section B, paragraph 6.'
Comment 83:
.The second~ sentence of this position should be amended to read as follows:
"...will not degrade, to any measurable extent, the bility of the equipment to perform adequately."
Regulatory position 2 requires that qualification testing be performed on the same piece of equipment in a definite sequence. Synergistic effects are to be taken into account.
The concept is to subject the equipment to accident con-dition simulation under the worst state of degradation.
Therefore any step in the sequence should be omitted (exempted) only if the degradation due to it is too low to be measured, or if that step improves, instead of degrades, the property of interest.
Allowing radiation exposure exemption merely because the degradation will be low does not consider the effect of combining this degradation with others due to other environmental effects.
Response (Comment 74 thru 83):
In general, the staff disagrees with these recommendations.
While the staff recognizes that all materials and equipment have some level (i.e., threshold) below which the effects of radiation can be ignored from a practical viewpoint,
- ~
an accurate definition of thresaold is needed.
Criteria need to be estab-lished for things such as operability, dose rate effects, combined environment 4
effects, etc.
It cannot simply be stated that everything can tolerate 10s op 103 Rads no matter how it is applied, '.r under what conditions. In summary, the staff believes that a threshold value would be a useful tool if it could be universally established, i
The present position, permits the. exemption of materials and equipment.from qualification testing at any level if previous operating experience or 6/16/83 73 2AGGAR/A
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previous qualification information can be provided which .ows operability of the materials or equipment for the planned radiation sn~tronment.
Use of materials referenced by such reports as EPRI report, "Radiation Effects on Organic Materials in Nuclear Plants," (Nov.1981) or to the Table included in Appendix C of the D0R Guidelines would constitute a reasonable justification for exemption from radiation testing for equipment located in areas where the integrated radiation doses are less than 104 rads.
Comment 84:
This position should be reworded to read as follows:
...that the effects of Beta radiation including heating and seccndary radiation, have no deleterious effects on component performance."
In the position as stated it is implied that only heating and secondary radiation make Beta radiation of concern.
Beta radiation may have direct effects similar to Gamma and may have unique effects on electronic components.
This should be recognized.
Response
The staff agrees with the comment.
Revised position C.4.c(6) incorporates the suggested wording.
Comment 85:
Recommend adding the following sentences at the end of the paragraph as l
follows:
Acceptable methods include the use of infinite or semi-infinite cloud models where applicable and justified.
Response
The staff has indicated in Appendix 0 to this guide that using the semi-infinite beta dose model is appropriate.
1 6/16/83 74 2AGGAR/A l
t
t o
Comment 86:
This position should be amended to read as follows:
"Qualification of the radiation environment should be performed taking into account the Beta and Gamma dose rates, etc... (e.g., reactor type and power level, containment size)."
Qualification testing is to be performed in a definite sequence on the same test sample.
Thus it is qualified only if each step in the sequence is passed.
Therefore, the initial portion of this position stating, "a given component may be considered qualified..., without failing," is misleading.
The modifica-tion suggested in the comment above would retain the sense of this position.
Comment 87:
This sentence-(C.4.c.(13)) should be ended with a period after the words
"...resulting from an analysis." The remainder of this sentence should be deleted. Appendix D and the other appendices are not a formal part of the guide and should not be referenced in the regulatory position.
Comment 88:
What is the point of this general statement? (C.4.c.(13))
It seems to be redundant; it may be better suited as an introductory paragraph to the section.
Comment 89:
If calculations are performed in accordance with the methodology described in Appendix 0 for development of radiation environments, no additional test margin is necessary due to the conservatisms used.
11/4/83-75 2AGGAR/A
Response (Comments 86 thru 89):
The staff agrees with these comments and revised Position C.4.c(5) to resolve these concerns.
Comment 90:
Analysis of the steam condition under various accident conditions and demon-stration of its effect will result in significant cost impact and a considerable number of re-tests.
The determination of effects of varying steam conditions (example - superheated steam followed by saturated steam), if critical, should be performed by the NRC or industry organization such as EPRI.
Response
Requalification of electric equipment will not be required provided the equip-ment is qualified in accordance with D0R Guidelines or NUREG 0583, as appropriate.
The staff believes that superheated steam followed by saturated steam is a limiting condition and should be considered.
Comment 91:
All reference to specific computer codes, and tne acccmpanying words - or equivalent industry ccJes, should be deleted.
The NRC staff should state the types of analyses required and not be specific as to analytical methods (i.e.,
computer codes).
The guidance as written raises obvious questions as to what constitutes "equivalence." The guidance as written is far too prescriptive.
Response
The reference to specific codes is made to indicate what methods would be an acceptable approach.
Referral to an "equivalent" method allows the user to propose an alternate which would be dealt with on a "case-by-case" basis.
Therefore, flexibility in approach is maintained.
F/16/83 76 2AGGAR/A
i o
Cor.sent 92:
The requirement to determine spatial distribution of pressure and temperature is both new and unnecessary.
The' recommended computer code CONTEMPT-LT is not capable of determining spatial distribution.
We recommend deletion of this requirement.
Response
This requirement is not new, but may have been worded differently than previous statements related to this subject.
The requirement has always existed that the analysis be demonstrated to be conservative.
The staff agrees that CONTEMPT-LT is not capable of determining spatial distribution.
Therefore, an analytical model for determining spatial distributions in conjunction with CONTEMPT-LT can be used.
The objective is to provide a model which will conservatively calculate the pressure-temperature spatial distribution.
Section C.4.d Comment 1:
The concept of environmental qualification should only be used to verify equipment performance and operability during or following hostile accident environments.
These Regulatory Guide items inappropriately require the use of such environmental qualification techniques outside of such hostile environn.ent areas.
We note that a basic misunderstanding exists which has confused the issue of environmental qualification and has drawn the Staff, and others, to the conclusion that environmental qualification is required for all safety-related equipment.
This misunderstanding is based in part on the inconsistent and over-lapping use of the terms such as "equipment environmental qualification" and "equipment performance demonstration".
11/4/83 77 2AGGAR/A
+
_,y,
The term "environmental qualification" is relatively simple to define.
It is the process of assuring that accident' environmental parameters will not generate common-mode failures in redundant safety systems or equipment which will prevent the performance of the system or equipment's safety function.
The methodologies used (testing, operating experience, analysis or their combination) provide such assurance by attempting to simulate with appropriate margins such environmental conditions and assess the ability of the equipment to perform its safety function.
The process is one which is typically performed once on prototypical equipment.
Equipment performance demonstration, on the other hand, can be defined as the process which provides overall assurance that individual installed equipment items are appropriately designed, manufactured and installed to meet their design intent.
The activities which comprise such a performance demonstration are typically (1) original design prototypical testing or analysis to verify inherent equipment capability to meet critical performance requirements, (2) testing, analysis or verification of the critical aspects of manufacturing and installation to assure they are properly performed, and (3) pre-operational and operational device testing to verify that the installed equipment meets its necessary performance requirements.
In a very real sense environmer.tal qualification for hostile environment equipment is a subset of such an equipment performance demonstration and is a part of activity (3) above dealing with prototype equipment qualification.
For mild environment equipment performance is not critically affected by such mild environments and therefore, equipment performance demonstration need not focus on environmental operability.
This does r.ot imply that critical activi<'es which can effect the performance of this equipment do not exist.
Critical activities, such as design selection, fabrication and installation do exist and are controlled.
The appropriate performance, control and verification of these activities including final operational testing constitutes equipment j
perf mance demonstration.
11/4/83 78 2AGGAR/A I
In sum, for such mild environment equipment, as with all safety-related equipment, performance demonstration in the sense of verifying that all critical operations affecting performance are properly performed is necessary.
Environmental qualification for such mild environment equipment need not be a required part of this performance demonstration.
Response
The staff agrees that the "environmental qualification" is a process of assuring that accident environmental parameters will not generate common-mode failures in redundant safety systems or equipment which will prevent the performance of the system or equipment's safety function.
The staff further agrees that the equipment incated in general plant areas outside containment where equipment is not subjected to a DBA environment should be designed to the range of environmental design basis conditions postulated to occur at the equipment location.
Since design considerations are beyond the scope of this Guide, Regulatory Position C.4.d(2) has been deleted.
For the following reason, Regulatory Position C.4.d(3) has also been deleted.
For equipment located in plant areas not served by environmental support systems or served by such systems that may be secured during plant operations or shutdown, the eauipment design should consider only the limiting environmental conditions for that location, assuming a loss of the environmental support system, e.g., HVAC.
Comment 2:
We recommend that only the equipment located outside containment that is exposed to a harsh environment due to the initiating event and is required to mitigate the consequences of that break shall require qualification to the conditions resulting from that break.
11/4/83 79 2AGGAR/A
Comment 3:
The "equipment" covered in this section should be limited to that which is required to mitigate the HELB or to achieve and maintain safe shutdown.
This distinction should be added to the Regulatory Guide.
Comment 4:
The first sentence (C.4.d(1)) should be revised to read:
"Class 1E equipment that is located outside containment, that could be subjected to a harsh environment resulting from a high energy line pipe-break, and that is required to perform a safety function for that accident, should be qualified to perform its safety function under the accident conditions".
Reference to the Standard Review Plan should be deleted.
Comment 5:
Position C.4.d(1) refers to the SRP as part of the position.
This use of the SRP in the position is not acceptable.
Either the proper information should L
be included in the regulatory guide or reference should be made to a proper source.
Comment 6:
The specific section of the Standard Review Plan (NUREG-75-0800) or the appropriate Branch Technical Position should be referenced.
"Equipment....
should be qualified to the conditions resulting from the accident for the duration required" should be changed to "Equipment.... required to m.itigate the specific high energy line break should be qualified to the conditions resulting from the accident for the duration required for that particular device to complete its safety function".
1 6/16/83 80 2AGGAR/A
Comment 7:
'Section C 4Ad(1)'should be revised to require only the qualification of equipment ~
that is required to mitigate'the consequences of. the HELB to which it is exposed.
Comment 8:
It'is' recommended that this section be revised to state that the equipment of concern is that required to function during or following the pipe break event; not all equipment influenced by the accident induced environment.
Comment 9:
1 Recommend revising C.4.d to read as follows:
"d Environmental Conditions for Class 1E Equipment Outside Containment" Recommend revising first sentence (C.4.d.(1)) to read as follows:
e
"(1) Equipment that is located outside containment that could be subjected to high-energy pipe breaks, and that is required to mitigate the consequences of that pipe leak should be qualified...."
i T
Comment 10:
The wording (C.4.d(1)) should be revised tc read "Equipment that is located outside the containment and that could be subjected to high energy pipe breaks and is required to mitigate the consequences of the break or required to bring the plant to safe shutdown should be qualified to the conditions resulting from the accident for the duration required."
11/4/83 81 2AGGAR/A
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Response (Comment 2 thru 10):
The staff generally agrees with these. comments.
Reference to the SRP has been deleted and the wording of the Regulatory Position C.4.d(1) has been revised to reflect the_ intent of these comments.
Comment 11:
Equipment is qualified "for" not "to" the conditions noted.
The discussion of DBA's excludes the common mode influences of the seismic OBE and this should be mentioned.
Response
The word "to" is changed to "for."
Electric equipment important to safety covered by 10 CFR Part 50.49 and this Regulatory Guide must be qualified for seismic stresses.
Reference to Regulatory Position C.2 should be made.
Comment 12:
As stated, position C.4.d(2) would require qualification (certification) of equipment that is not subjected to an accident environment.
This is not necessary. We recommend deleting C.4.d(2).
Comment 13:
In Sections C.4.d(2)'and C.S.a of this Guide, we agree with the Staff's statement j
that equipment located in a mild environment is not required to be qualified by testing.
However, in defining the mild environment, use of the terms
"... abnormal range of environmental conditions postulated to occur..." and
"... an environment that would at no time be more severe than the environment 6/16/83 82 2AGCAR/A
j that would occur during norral power plant operation or during anticipated
- operational occurrences" require that all equipment be designed for all postulated environmental conditions.
It is impractical and not cost effective to design all equipment on this basis.
It is, however, practical and cost effective to establish an environmental design basis that employs techniques such as tempera-ture monitoring or operator action to insure equipment operation in some abnormal environments that may be postulated to temporarily exceed the equipment design specifications.
Based on the above discussion, we recommend that Sections C.4.d(2), C.4.d(3),
and C.S.a be revised as follows:
C.4.d(2):
Equipment located in general plant areas outside containment where equipment is not subjected to a design basis accident environment is in a mild environment.
This equipment should be qualified to the environmental conditions postulated to occur at the equipment location as derived from the plant environ-mental design basis.
C.4.d(3):
Recommend deleting paragraph.
Comment 14:
Equipment located in general plant areas outside containment where equipment is not subjected to a design basis accident environment is in a mild environment.
This equipment should be designed to the environmental conditions defined by the plant environmental design bases for the location of the equipment.
Comment 15:
As stated in C.4.d(1), equipment subject only to mild environments does not need to be qualified. 'Other activities performed in accordance with quality assurance programs assures that this equipment can perform its required safety i
l 11/4/83 83 2AGGAR/A
function.
The separate listing (as part of the equipment qualification documen-tation) and qualification of this equipment would impose a substantial burden on utilities without a significant improvement in safety.
It is recommended that the scope of this Regulatory Guide be limited to required safety related electrical equipment potentially subject to harsh DBA environments (i.e.,
l paragraphs C.4.d(2) and (3) and C.5.a should be deleted).
I i
Comment 16:
We recommend that general plant areas outside containment which are not subject to a design basis accident environment be defined as a mild environment.
Equipment located in these areas should be qualified to the environmental conditions derived from the plant environmental design basis.
Response (Comment 12 thru 16):
Regulatory Position C.4.d(2) has been deleted.
See response to Comment 1 (page 79).
Comment 17:
The meaning of this paragraph is totally unclear.
What is meant by the phrase "Equipment... served by other systems within the scope of this guide that may be secured during plant operation or shutdown..."? Are the "other systems" referred to other environmental support systems? Why is a "loss of environmental support system" assumed? The intent of this entire paragraph should be clarified or the paragraph deleted altogether.
6/16/83 84 2AGGAR/A
e Comment 18:
Regulatory Position C.4.d(3) "Conditions Outside Containment." The meaning of this paragraph is not clear as to what systems are of concern.
It should be re-written for clarification. What is the meaning of the term "environmental support System" as used in this context? Would HVAC systems be one example?
Are there others?
Comment 19:
The wording of this section is unclear.
We suggest substitution of the following wording:
Equipment which is either (a) not served by Environmental Support systems within the scope of this guide or (b) served by other support systems within the scope of this guide which may be shut down or secured during plant operation should be qualified to the limiting environmental conditions for its location that may be expected to occur with the support system not operating.
Response (Comment 17 thru 19):
Regulatory Position C.4.d(3) has been deleted.
See response to Comment 1 (page 79).
Comment 20:
We agree that equipment located outside containment that could be subjected directly to high-energy pipe breaks should be qualified to harsh environments.
However, it is possible that adjacent rooms may experience small effects from a HELB, e.g., temperature rise, which may De less than the effects resulting from an abnormal operating condition.
Strict interpretation of this paragraph would require a qualification process dictated by a harsh environment.
We propose that the subject paragraph be modified as follows:
11/4/83 85 2AGGAR/A
o "Equipment that is located outside containment and in locations that could be directly subjected to high-energy pipe breaks..." Add a new sentence:
"Equipment which is indirectly subjected to high-energy pipe break effects such that the abnormal range of environmental conditions are not exceeded should be qualified in accordance with C.4.d.(2)."
Response
Equipment, which is indirectly subjected to HELB effects such that the abnormal range of environmental conditions are not exceeded, should be considered as located in a mild environment.
Section C.5 Comment 1:
The mild environment definition cannot be legally met since (for example) radiation penetrating the containment would, by definition, result in environ-ments "more severe than... that would occur during normal power plant opera-
+ ion or during anticipated operational occurrences," although minutely small.
Thus, a specific numerical value must be given.
Comment 2:
The definition for mild environment (i.e., "an environment that would at no time be more severe than the environment that would occur during normal power plant operation or during anticipated operational occurrences") is not reason-able.
Based on the required assumptions for a DBE, there are a number of areas within the average plant that will see only a very slight rise in some of the parameters following a DBE.
These areas would remain accessible with only minimal additional stress on equipment.
However, the definition given would require the same level of te*, ting as required for equipment located inside containment.
11/4/83 86 2AGGAR/A
Response (Comment 1 and 2):
The definition of mild environment was modified in the final rule.
The word "significantly" more was added, namely, "an environment that would at no time be significantly more severe than the environment that would occur during normal power plant operation, including anticipated operational occurrences."
Comment 3:
The definition of "mild environment" in Section C.S.a needs clarification with respect to radiation. We believe it is reasonable to define a "mild environment" as one in which the pressure, temperature, and humidity during an accident do not significantly exceed the values expected during normal operation or antici-pated operational occurrences.
It is possible that the radiation dose rate anywhere in the plant during an accident will be measurably more severe than during normal operation or anticipated operational occurrences.
That dose rate may be trivially small in "mild" areas (for example, in the control room), but even so, the current definition of "mild environment" would not be met.
We believe this point should be clarified.
Response
The staff believes that a change in total integrated radiation dose up to a value of 10,000 rads should not be the basis for mild environment exclusion when this radiation is clearly below an equipment's threshold of radiation induced degradation.
However, for electric components, studies have shown failures in metal oxides semi conductor devices at somewhat lower doses.
Therefore, radiation qualification for electric components may have a lower exposure threshold.
Comment 4:
For clarification, the first sentence (C.S.a) should be revised to state:
. are not required to be environmentally qualified by test.
"; and 11/4/83 87 4AGGAR/A
o q
the last line should be revised to read:
... such equipment will perform l
its specified safety function throughout its anticipated installed life".
We strongly recommend that the Staff should amplify what constitutes acceptable "test data and analysis" and how this~ differs from normal qualification data.
{
It is not apparent how the Staff's recommendations for addressing the' environ-mer.tal qualification of equipment in mild environments interface with require-ments for seismic qualification. We strongly recommend that the Staff should amplify its recommendations in this area to completely resolve this issue once and.for all.
In particular:
Since virtually all equipment located in a mild environment is required to remain functional under safe shutdown earthquake conditions (i.e., 10 CFR 100), what are the Staff's recommendations concerning the test sequence to be employed and, in particular, the need to address aging for such equipment.
Response
For clarity, the staff agrees to include the word "environmentally" in the first sentence.
Equipment importar.t to safety that is located in a mild environment is subject to the vibration environment (including seismic) a'pplicable to its location and must be qualified to it.
These requirements are covered by Regulatory Guide 1.100, which endorses IEEE344-1975.
It should be noted that the staff has not taken a formal position at this time with regard to the need to address preaging prior to seismic testing for such equipment.
Comment 5:
The first sentence of this position should be modified as follows:
"Any of the equipment identified in item (2) and (3) of Regulatory Position 4.d which are in a mild environment...need be qualified by test only for their vibra-tion environments (including seismic)."
e 11/4/83 88 4AGGAR/A l '
E e
. 6'
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Response
This issue will be addressed in Regulatory Guide 1.100.
See response to Comment 4 (Page 88).
Comment 6:
The term "anticipated operational occurrences" at the end of first sentence appears to be synonymous with "abnormal conditions." If so then it is suggested that "abnormal power plant operation" be used.
If it is intended to mean otherwise then its meaning should be defined.
Response
Anticipated operational occurrences mean those conditions of normal operations which are expected to occur one or more times during the life of the nuclear power plant.
This definition is included in 10 CFR Part 50, App. A. (page 406, Codes of Federal Regulations, Jan. 1, 1982).
Comment 7:
Equipment in a mild environment should not need qualification certification in accordance with this guide. We recommend changing the last sentence to read:
"A well-supported surveillance program in conjunction with a good preventative maintenance program should be provided to ensure that such equipment will perform its safety function when required."
Resoonse:
This sentence has been deleted.
Comment 8:
Position C.5.a., states that equipment in mild environment locations may be qualified, in part, through "...a certificate of compliance based on test data and analysis...".
The meaning here is not clear.
If the intent is that all 11/4/83 89 4AGGAR/A l
+
4 certificates of compliance must contain words similar to "... based on test data and analysis...", the position will only invalidate a lot of certificates of compliance and will not improve the qualification of any of the equipment at any plant.
It is more likely that the intention is to ensure that manufac-turers do not arbitrarily assign specification values to get their equipment accepted.
The concern is not valid for equipment located in mild environments in nuclear power plants.
It is recommended that the words "... based on test data and analysis..." be deleted to avoid an interpretation that will resuit in certificates of compliance being considered invalid and a rush to get new certificates - which will consume time and money but will rot improva safety.
Response
The Regulatory position C.5.a has been modified.
The Guide does not include requirements for equipment located in a mild environment.
Comment 9:
The second sentence of this paragraph (C.5.a) should be deleted.
Equipment in mild environments is proven qualified on the basis of operating experience.
not on the basis of a "certificate of compliance" for a design specification.
Any equipment failures occurring in mild environments are generally random in nature and are identified and corrected in accordance with plant surveillance and maintenance programs.
Moreover, equipment in these areas would be acces-sible for servicing as needed during accident events.
A well-supported surveillance and preventive maintenance program should be sufficient b stifica-tion in itself for demonstrating quelification of equipment in mild environments.
Comment 10:
The guidance of this section was not previously required for plants developing qualification information per the interim requirenents.
For existing equipment in these plants the operability of such equipment to date and the performance of surveillance, periodic testing and maintenance activities provides an adequate level of confidence in this equipment's operability.
The requirements of this section (C.S.a) should be imposed only on new or replacement equipment 11/4/83 90 4AGGAR/A
s-c purchases, not existing equipment for operating plants.
To perform a documentation search for certificate of conformances and required test condi-tions to that of existing environmental conditions in a non-harsh environment will result in no incremental increase in the safe operation of the plant.
Comment 11:
The first part of this position (C.5.a) waives the qualification by test.
However, the second part requires "...a certificate of compliance based on test data and analysis..." Although the waiver of the type test for the equipment located in the mild environment looks like a relief from an unneces-sary burden, the new requirement for a "certificate of compliance based on test data and analysis" is equally unjustified. We think that "a certificate of compliance stating that the equipment was des.igned, an1 manufactured consis-tent with standard engineering practices and industry codes and standards" should be sufficient.
Response (Comment 9 thru 11):
Sue response to Comment 4 (page 88) and Comment 7 (page 90).
Comment 12:
It is the primary role of qualification to assure that Class 1E equipment can perform as specified and to provide assurance that no failure mechanism exists that could lead to common mode failures under postulated service conditions.
The extreme environments resulting from DBAs present the greatest potential for causing common mode failures of Class 1E equipment, whereas, environments not affected by DBAs have little potential for producing common mode failures.
Failures of equipment in these areas are random and the equipment is generally accessible for repair.
For these reasons it is necessary to establish a qualified life for equipment which is subjected to DBA environments that exceed the normal and abnormal environments in which they are located.
This shall be accomplished by the l
11/4/83 91 4AGGAR/A
2
.a qualification methods described in the remainder of this standard which include type testing, operating experience, analysis, ongoing qualification, or any combination of these methods.
For equipment located in areas whose normal and abnormal environments are not exceeded by DBA environments, it is not necessary to establish a qualified life.
An adequate level of assurance of the capability of this equipment to perform its Class 1E function can be achieved by demonstrating by test and analysis that the equipment can perform these functions at the extremes of the service csnditions.
It is not necessary to use the qualification methods described in the remainder of IEEE-323-1974 since they are directed toward the establishment of a qualified life.
In addition, a surveillance program shall be implemented to detect time-dependent degradation that might compromise the required capability and a maintenance program shall be implemented to perform maintenance recommended by the manufacturer.
Response
The staff agrees with the principles outlined in this comment.
Comment 13:
Testing or reasonable analysis would be acceptable for "mild" or "harsh" equipment.
The requirements of the Standard Review Plan (NUREG-0800) seem to contain more guidance than this proposed regulatory guide on mild equipment.
NRC should allow qualification documentation using the same rigor on mild equipment as on harsh equipment to demonstrate that an intensive maintenance and surveillance program is not warranted.
We recomrcend reference to Enclosure 4, Appendix C-1 of IEB 79-018 as an accept-able document for addressing the effects of aging.
Also, in response to question (7) as per Supplement 2 to IEB-79-018, the NRC indicated that IEEE 650 (Standard for Qualification of Class 1E Static Battery Chargers and Inverters for Nuclear Power Generating Stations) methods and procedures relating to design stress analysis, aging and the identified stress test are acceptable 11/4/83 92 4AGGAR/A
6' 4
for qualifying components which are not exposed to harsh environments.
This NRC position should remain valid under the proposed revision to R.G. 1.89.
The use of qualitative terms such as "well-supported surveillance" and "good preventive maintenance" will only lead to protracted interpretations and clarifications.
Much equipment is qualified without dependence on refurbish-ment and corrective maintenance (e.g., cables, motors, terminal blocks, fuses etc.) as the basis for qualification.
In fact the normal service environment for non-nuclear power plant service may be far more severe than nuclear plants without dependence on "well-supported surveillance" and "good maintenance" for success.
Response
See response to Comment 4 (page 88).
Comment 14:
IEEE 323-1974 specifically calls for pre-aging followed by a seismic test.
However, Regulatory Position C.S.a states that certain equipment are not required to be qualified by test if they are in a mild environment.
As it stands, this means either:
1 l
a)
This guide waives all testing for mild environments including seismic, or 1
b)
The guide intentionally avoids addressing the seismic question.
1 A qualification program necessarily must address environmental and seismic considerations jointly.
Therefore, we request that the NRC provide further guidance or clarification to resolve this ambiguity.
Response
Equipment located in mild environment must be qualified for seismic stresses, in accordance with R.G. 1.100, 11/4/83 93 4AGGAR/A
z Section C.S.b Comment 1:
This paragraph is implicitly understood.
The enclosure is a safety-related equipment item. Why is it called out separately?
' Comment 2:
As written the use of a watertight box requires that it be qualified as such.
The type of equipment used does not always mean use at its highest design capability.
The functional use of the device should determine the qualifica-tion level.
We propose the following modification:
"Equipment located in watertight enclosures, when functionally required to be watertight, should be qualified..."
Comment 3:
The first sentence of this section should be modified to require testing only for enclosures subject tu spray and/or submergence.
Connent 4:
The first sentence implies that all watertight enclosures should be tested regardless of location.
This is unnecessary since some enclosures could be used as a matter of choice in applications which would not be subjected to flooding.
Comment 5:
This position refers to testing equipment within watertight enclosures.
It should refer only to testing the watertight enclosures themselves.
11/4/83 94 4AGGAR/A
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i Comment 6:
Position C.S.b would be clarified if the first sentence was changed to read as follows (change underlined):
"Equipment located 'in watertight enclosures should be qualified by test that demonstrates the adequ.3cy of such protection if the watertight integrity of the enclosure is required for the safety related function of the equipment."
Comment 7:
C.5.b:
Clarification is required for the requirement that "equipment located in watertight enclosures should be qualified by testing..."
Many utilities standardize on NEMA Type 4, "watertight" enclosures even for splice boxes containing MSLB/LOCA qualified splices and such designs do not depend on watertight box / enclosure integrity for safety function; therefore, watertight integrity need not be tested.
The requirement that "equipment that could be submerged...and demonstrated to be qualified by testing..." exceeds NRC guid-ance previously provided and accepted which allows a failure modes and effects analysis review to determine if a potentially submerged device which is not qualified for submergence will preclude completion of plant safety function.
Comment 8:
This section contains an implicit assumption that watertight enclosures are provided only for equipment whose functionability depends on watertightness or, alternatively, that compromise of watertightness of submerged equipment is tantamount to failure.
Neither assumption is accurate. Watertight enclosures may be provided as defense-in-depth for devices that can operate even with water intrusion.
The qualification test for a device that could be submerged is required to demonstrate functional operability for the duration required irrespective of demonstrated watertightness.
In general, seal integrity is desirable, but not necessary in all cases.
Also, the intent of the last sentence might benefit from the recommended rewording.
11/4/83 95 4AGGAR/A
n t
4 Replace with:
"b.
Equipment that could be submerged should be identified.and qualified by' testing in a submerged condition to demonstrate operability for the duration required.
Analytical. extrapolation of results for test periods snorter than the required duration should be justified."
Comment 9:
The location of equipment within an enclosure to provide environmental protec-tion is a standard design practice used to assure equipment operability.
The industry's use of such protection is not limited to "watertight" enclosures but encompasses the spectrum of enclosure classifications as defined in NEMA Publication No. 15-1.11973 HEMA 1:andards Publication Enclosures for Industrial Controls and Systems.
The use of enclosures classified and tested in accordance with this NEMA publication should be considered as adequate demonstration of their capability.
The second issue addressed by this item is the submergence of equipment not within a protective enclosure. We maintain that analysia and operating exper-ience appropriately applied and particularly when augmented by partial type testing are acceptable methods of assuring such equipment's operability.
In addition, submergence testing of equipment to the requirements of NEMA Publi-cation No. 15-1.1, Section 1-110.59 for enclosures should be acceptable.
C.S.b should be reworded as follows:
b.
Certain equipment mey be located in an enclosure and its safety function performance may be predicated on the protection provided by such an enclosure.
For this equipment, the enclosures' protection should be demonstrated to assure the adequacy of the protection provided.
Testing in accordance with NEMA Publication No. 15-1.1 is one acceptable method of demonstrating such protection.
Equipment that could be submerged should be identified and demonstrated to be qualified by testing (such as that described in NEMA Publication No. IS-1.1, Section ICS 1-110.59), operating experience, analysis or a combination of these methods.
11/4/83 96 4AGGAR/A
3 Comment 10:
Recommend deleting first sentence and revising second sentence as follows:
"Equipment required to perform a safety function while submerged should be identified and demonstrat.ed... "
Comment 11:
Delete the first sentence since it is unnecessary.
Response (Comment 1 thru 11):
The staff agrees that the first sentence is unnecessary and should be deleted.
The staff believes that the equipment located in watertight enclosures should be qualified by test that demonstrates the adequacy of such protection if the watertight integrity of the enclosure is required for the safety function of the equipment.
The Regulatory Position C.S.b has been reworded to reflect the intent of Comment 8.
Section C.S.c Comment 1:
The effects of time-dependent variations of relative humidity conditions is beyond the state-of-the-art.
The effects of exposure to high levels of rela-tive humidity should be, and generally are, considered in a qualification program.
Time-dependent variation effects should be a subject for research.
This section also implies that the most adversi %u:..idity condition must be applied simultaneo,$ly with the most adverse prw sure condition regardless of the fact that they may not occur simultaneously.
Comment 2:
Consideration of time-dependent relative humidity conditions is unwarranted.
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6
.o Comment 3:
Position C.5.c. is not clear.
The intent seems to be to apply an artificially severe combination of parameters (pressure and humidity).
The position should require the application of these parameters in a realistic or conservative manner that demonstrates the adequacy of the seals and barriers.
Comment 4:
Revise the position as follows:
Equipment located in an area where rapid pressures are postulated should be qualified to demonstrate that, under the most adverse pressure transient for the equipment location, the equipment will perform its required safety function for the length of time the equipment function is required.
Comment 5:
Recommend revising paragraph as follows:
"c.
Equipment located in an area where rapid pressure changes are expected should be qualified to demonstrate that, under the most adverse humidity conditions and the most adverse postu-lated pressure transient...."
Also, recommend inserting safety before "functions" in last line.
Comment 6:
Section C.S.c seems to require an artificially severe combina'. ion of pressure and humidity.
For all practical purposes the atmosphere inside containment following a DBA w'.11 be at 100 percent relative humidity.
Comparison of the pressure-temperature profiles for the various plants provided in the FSAR and IE Bulletin 79-018 submittals would establish:
(1) The degree of superheat involved in the few cases in minimal; and (2) Duration of superheat condition is on the order of a few minutes.
It is therefore, considered to be an insig-nificant facto, in the qualification testing to address the time dependent humidity considerations.
11/4/83 98 4AGGAR/A
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C Comment 7:
If bounding values of relative humidity can be shown to be conservative, use of these bounding values should be permitted (i.e., with respect to humidity in particular, time-dependent variation determination should not be required).
Comment 8:
Since the most adverse humidity conditions and most adverse pressure transient do not necessarily occur simultaneously, a clarification is needed.
In the last' clause, the phrase "to the degree necessary..." may be mistakenly read to modify the verb "penetrating" rather than the intended verb "prevent".
Also, it is more precisely functionability and not integrity that must be maintained.
Respon,se (Comment 1 thru 8):
The staff agrees that the effects of time-dependent variations of relative humidity conditions are beyond the state-of-the art.
Thus, the words "time-dependent" have been deleted.
The Regulatory Position C.S.c has been modifiet to reflect the fact that the most adverse humidity conditions and most adverse pressure transient would not necessarily occur simultaneously.
Comment 9:
Tae Staff guidance provided by this item addresses the effect rapid environ-reental pressure changes may have on the ability of equipment or enclosures to prevent moisture or water incursion.
We believe this can be addressed in a clearer fashion by an appropriate rewording.
The statement as it stands implies that if two accident environments exist, the first with a rapid exter-nal pressure change and no high noisture condition and the second with no rapid pressure change but a high.noisture condition, then licensees must 11/4/83 99 4AGGAR/A
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qualify the equipment to the simultaneous occurrence of both environments.
We do not believe this to be the Staff's intent, and therefore the item must be clarified.
Environmental qualification for such conditions need not be limited to the i
sole use of testing.
Analysis, operating experience or a combination of these methods can provide an adequate demonstration of qualification.
We recommend that the Regulatory Position C.5.c be reworded as follows:
Equipment located in areas where rapid pressure changes and high relative c.
humidity conditions (such as steam) concurrently exist should be qualified to demonstrate that the equipment enclosure, seals and vapor barriers will prevent moisture from penetrating inte the equipment as a result of the rapid pressure changes to the degree necessary to assure that the equipment can perform its safety function for the length of time the equipment furiction is required.
Response
See Response to Comment 1 thru 8 (page 100).
Comment 10:
Analysis in lieu of testing should be acceptable.
+
Response
The staff believes that the qualification for environmental conditions cannot j
be sttisfactorily demonstrated "by analysis only."
Section C.S.d l
Comment 1:
Why is tempe-M ere called out separately? What about radiation dose and rate, chemical spray, etc.?
11/4/83 100 4AGGAR/A
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Response
Regulatory position C.5.d has been generalized.
Comment 2,:
Revise this section to read:
"The temperature in the test chamber to which equipment is being qualified by exposure to a simulated environment should be obtained by temperature measurements taken sufficiently close to the equipment to characterize its environment."
Comment 3:
Recommend revising paragraph to read as follows:
"d.
The temperature in the test chambers at which equipment is being qualified by exposure to a simulated environment should be obtained by temperature measurements sufficiently close to the equipment to characterize its envircnment."
Response (Comment 2 and 3):
For clarity, the paragraph has been modified, reflecting these comments.
Comment 4:
It is conceivable that temperature readings in a type test chamber could be too close as well as too far from equipment to adequately characterize its environment.
Replace last phrase with:
"... by temperature readings at a distance from the equipment that best characterizes its environment."
i h
11/4/83 101 4AGGAR/A
Comment 5:
Temperature measurement point should be a reasonable representation of ambient temperature to which equipment is being qualified in a specific test.
Placing "temperature readings sufficiently close to the equipment" may not represent the ambient expected in a real accident due to heat sink characteristic of equipment.
Comment 6:
Delete this section (C.S.d).
The subject of finite temperature zones within the containment was discussed during a NRC meeting held July 7-10, 1981 and referenced by the Franklin Research Center.
It was concluded that analysis required to address this topic is beyond the state-of-the-art.
Response (Comment 4 thru 6)
The staff believes that the measurements should be taken sufficiently close to the equipment to represent environments expected in a real accident.
Comment 7:
This item requires that the test chamber temperature near the device be recorded and used to categorize the device's thermal environment.
The guidance is good l
testing practice, but should not be required as a backfit to testing previously performed. The exclusion of this practice or its documentation does not indicate that previous testing was inappropriately performed.
Response
l l
Requalificatioil of equipment previously qualified ir, not required.
i i
11/4/83 102 4AGGAR/A
Section C.S.e Comment 1:
The use of the term "performance characteristics" may be open to wide interpre-tation.
For example, must motor performance characteristics, i.e.,
starting torque, breakdown torque, etc., be verified before, after, and periodically during testing? We feel that this was not the intent and functional operabil-ity was meant.
We propose that the first sentence be modified to read:
"Functional operability of the equipment should be verified before, after, and..."
Comment 2:
Recommend revising first sentence (C.5.e) as follows:
"e.
Safety function requirements of class IE equipment should be verified before, after, and periodically during testing when practical.
Momentary failures which could adversely affect the performance of the safety function should be addressed during testing."
Comment 3:
The term "performance characteristics" should be explained.
Response (Comment 1 thru 3).
The staff agrees that only those performance characteristics that demonstrate the operability of equipment should be verified.
The Regulatory Position C.5.e has been acccrdingly mcdified.
Comment 4:
We believe that what the NRC means ir. the last sentence in Paragraph C.S.e is that continuous monitoring for extended periods nf time is not required; but 11/4/83 103 4AGGAR/A
(
s.
-a..
m that a representative amount of monitoring is required.
We suggest the removal of the word "continuous" in the last sentence.
Comment 5:
t The last sentence is confusing as written.
"Continuous monitoring during periodic intervals" is an impossible task.
R: s;,onse (Comment 4 and 5):
The staff agrees..The work "continuous" has been deleted.
Comment 6:
Position C.S.e. should be rewritten, in part, as follows:
"Safety related performance characteristics that demonstrate the opera-bility-of the equipment should be verified...".
Where no momentary failure during the testing can be reasonably postulated and when operability during the testing can be adequately justified by verfication after the testing is complete, monitoring and operating the equipment during i
the test is not required.
This is particularly true for Class 1E equipmont outside containment whose onl;. testing is for the radiation dose received from recirculating fluids.
This position should be changed to reflect this comment, Comment 7:
j Replace the first sentence with the following:
"Variables indicative of momentary failures that prevent the equipment from performing its safety function shall be monitored continuously."
I r
I 11/4/83 104 4AGGAR/A
7 1-
?=
Response (Comment 6 and 7):
The staff agrees. Variables indicative of momentary failures that prevent the equipment fron, performing its safety-function should be monitored continuously.
The Regulatory Position C.S.e has been modified.
See Response to Comment 1 thru 3 (page 104).
Comment 8:
This section (C.5.e) states that "performance characteristics of equipment should be verified before, after, and periodically during testing throughout its range of required operability."
Operation throughout the range of required operability is generally not pr.ic-tical for short term transients such as during seismic testing or HELB testing.
In such instances, an engineering judgment will be made to monitor the most critical parameter or worst case condition only.
Comment 9:
This position does not clearly discriminate between equipment that must operate throughout an event and that which can operate afterwards.
We suggest adding a parenthetical statement after the first sentence to make this distinction clear.
Response (Comment 8 and 9):
See responses to Coh;ent 1 thru 3 (page 104) and Comment 6 and 7 (page 105).
Comment 10:
This item (C.5.e) requires that safety function performance characteristics be recorded in a way which assures that momentory failures are detected during testing.
The guidance is good testing pr&ctico, but should not be required as a backfit to testing previously performed.
The exclus'en of this practice or its documentation does-not indicava that previous testing was inappropriately performed.
11/4/83 105 4AGGAR/A
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Response
Requalification of equipment previously qualified is not required.
Section C.5.f Comment 1:
Suggest rewording "... at or near the pressure and temperature conditions that would occur when the actual spray systems actuate.'"
Comment 2 The signiflcance of spray actuation at or near the maximum pressure and temperature conditions that would occur should be clarified.
Testing is usually performed at temperatures and pressures well above the anticipated conditions that would occur during the accident and is, considered testing to the worst case environment.
Response (Comment I and 2):
i The words "or near the maximum" have been deleted from the Regulatory Position C. S. f.
Section C.S.o Comment 1:
We recommend deleting paragraph c.5 0 as the requirement of IEEE-323-1974, section 6.3.1.5 (margins) are adequate to address the effects of voltage and frequency variation.
i Comment 2:
l Recommend deleting paragraph (C.S.9).
11/4/83 196 4AGGAR/A
~~'-
e.
The requirement of IEEE-323 1974, section 6.3.1.5 (margins) are adequate to address the effects of voltage and frequency variation.
These effects are addressed by design and/or type and rating test.. Qualification testing costs would be unnecessarily increased by this paragraph.
Comment 3:
The requirements of Section C.5.g are not always appropriate nor practical for all types of equipment.
We recommend that this section be deleted from the Guide.
Comment 4:
"Expected extremes in power supply and frequency should be applied appropriately during simulated event testing."
Anticipated worst case cce.i4on should be allowed in lieu of testing for expected extremes.
Comment 5:
Design verification tests prove the ability of equipment to function within specified limits of voltage and frequency.
To require the addition of voltage and frequency extremes to simulated event testing will not result in an increase to the safe operation of the equipment or the plant.
The most conservative limitation in power source should be used during qualification testing to prove operability under the combination of adverse environment and specified power source conditions, since they could both occur simultaneously.
- However, both ends of limits (i.e.
high and low) are not necessary.
Comment 6:
Application of voltage and frequency extremes during event testing may not be i
feasible; post event testing may be the point to consider extremes of voltage 11/4/83 107 4AGGAR/A
s o,
C and frequency.
Alternately a. review of standaid equipment voltage / frequency design basis may demonstrate that extremes.in voltage / frequency need not be
~
considered.
Comment 7:
In position C.S.g., add the phrase "...if expected to affect the required operability of equipment." Without this phrase, the position could'be mis-interpreted as.being mandatory in every case.
For some equipment, however, the acceptability of using nominal or conservative values'can be justified.
Commot 8:
In the majority of cases, safety-related equipment is supplied by a guaranteed stabilized power supply and thus variations in supply voltage and frequency are not considered significant.
In other cases, selection of conservative-design assumptions or test conditions can address the concern of varying supply voltage and frequency..As a consequence, we recommend this sentence be revised to read:
"Expected extremes in power supply voltage and frequency during the design basis event should be considered during the development of the
[
qualification test plan and specifically addressed if pctentially significant with respect to the intended safety "function".
4 P
Comment 9:
Expected extremes in supply voltage and *requency need not be applied during all simulated event testing.
Such extremes need only be required when they can be shown to affect equipment safety function performance and the outcome of the associated testing.
Failure Modes and Effects Analysis or other mea-
[
surements (such as highpotting) obviate the need to universally apply such f
extremes.
I By universally requiring the use of such extremes, the Staff will unnecessarily i
complicate many qualification tests.
In the absolute, this item would be I
11/4/03 108 4AGGAR/A t
i
interpreted to require one complete set of tests to simulate each operating extreme. This type of testing is unnecessary and wasteful -
For example, in cable testing the use of insulation resistance measurements, voltage withstand testing, and post-LOCA mandrel bend testing are the techni-ques which provide information on the cable's ability '.o adequately function.
-The use of voltage and frequency extremes would provide no additional informa-tion and is of little value.
Response (Comment 1 thru 9):
The staff agrees that the requirements of IEEE 323-1974 (Section 6.3.1.5) are adequate to address the effects of voltage and frequency variation.
Thus the Regulatory Position C.S.g. has been deleted.
Section C.6.a Comment 1:
It is not clear that margin can account for statistics (point 2 of the para-graph), at least in a quantifiable way.
Point 4 of the paragraph is not margin; it is in addition to margin.
Response
Paragraph C.6.a.(2) has been deleted.
The suggested values for cargin (except time margins) as stated in IEEE 323-1974 are acceptable in meeting the require-ments of Section 50.49 of 10 CFR Part 50.
Comment 2:
In position C.6., the phrase "... plant specific margins,..." is not clear.
Please provice a better description of the intended meaning of this phrase in order to allow proper interpretation of this position.
11/4/83 109 4AGGAR/A
e 4
In position C.6.a., the phrase "...(e.g., when only a few units are tested),,.."
is used under'(2) where the functions of margin are described.
The connection between "...(2) account for uncertainties associated with defining satisfactory performance..." and the phrase of concern is not-clear.
The phrase can lead to misinterpretation whereas item (2) stands well on its own.-
It is recommended that the phrase "... (e.g., when only a few units are tested)..." be deleted.)
Response
The staff agrees.
The recommended deletions have been made.
Comment 3:
Requirements for margin above and beyond the conservatively determined para-meters (other than test instrument tolerance) is unwarranted.
This position was found acceptable to the NRC steff in comment / resolution 70 in NUREG-0588, Revision 1.
Response
If conservations applied during the derivation of local environmental conditions of the equipment can be quantified and shown to contain appropriata margins, additional margins are not required.
If this cannot be accomplished, the margins as specified in IEEE 323-1974, (except time margins) are acceptable.
Comment 4:
Regulatory Position C.6.a is unclear concerning the base parameters to hich quantified margins are to be applied.
We recommend that the term "design parameters" be deleted and "most severe service conditions" be used in its place--this recommended term is the original term appearing in IEEE 323-1974 I
and is more specific.
Margins for qualification should be added to the most severe service conditions and not to design parameters.
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e l
Response
The term "design parameter" has been deleted.
Reference is made to environmental parameters instead.
Comment 5:
The Staff positior., articulated in NUREG-0588, (Part II, Resolution to Comments 70A, B, and C at page 11-37) should be incorporated into this item.
That position stated that the use of conservative licensing models to develop environmental parameters (i.e., LOCA pressure, temperature, radiation, etc.)
provided adequate margin to account for all uncertainties except for inaccura-cies in the test equipment. We concur-with this Staff position.
Furthermor9, the DOR Guidelines in Section 6 Margin stated that "... no separate margin factors are required to be added to the service conditions...", provided other guidance contained within the DOR Guidelines were used.
Response
Requalification of equipment previously qualified (NUREG 0588 or 00R Guidelines) is not required.
Margins must be applied to account for unquantified uncertainty such as the effect of production variations and inaccuracies in test instruments.
Comment 6:
No separate margin factors should be added to the service conditions when specifying test conditions.
Service conditions are very conservative with re, ect to plant operating conditions.
The 00R Guidelines state that a "factor applied to the time equipment is required to remain functional is the most significant in terms of additional confidence in qualification".
The service conditions have been calculated to include "conservatisms which assure margins 11/4/83 111 4AGGAR/A t
4
, t
s between service conditions specified and the actual conditions which could realistically be expected in the design basis event ("Bulletin 79-01B, Attach-ment 4 Page 14").
Many utilities have undergone extensive qualification testing to service conditions unique to their plants in accordance with IEEE 323-1971 and demonstrated compliance with the previous NRC regulations. We believe that no additional work is required and that the staff should maintain their previous position.
Response
See response to Comment 5 above.
Comment 7:
It is inappropriate to account for inaccuracies of test equipment by the application of vaguely related margins.
Equipment accuracy considerations are dealt with in Q.A. programs, not qualification programs.
To mix them up as is done in this requirement means that margins may be improperly used to excuse poor Q. A. practices of instrumentation calibration and drif t or conversely to give no credit for good Q.A. practices when in fact they are used.
My use of the terms "vague" above is I believe appropriate because of the very undefined means available to "account" for an undetermined error in one factor by plugging in a dediberate conservative error of another function when the relationship between the two functions is complex and largely unknown.
This was the reason that the original 323 working group was admittedly totally arbitrary in listing marginal factors.
The Page 11 top paragraph seems to try to put this margin on some kind of a pseudoscientific basis but truly it must be recognized as a form of game playing with admi'.tedly very tenuous logic.
It is "vague".
Comment 8:
The "inaccuracies" mentioned are not part of equipment qualification but are part of the QA program having to do with calibration.
Should be deleted.
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i Response (Comment 7 and 8):
The staff believes that it is appropriate to account for inaccuracies in test instruments.
See also response to Comment 3.
Comment 9:
It should be clarified that if the suggested margins of IEEE 323-1974 are applied to the conservatively-derived environmental profiles, no further quantification of margins is required.
Response
The staff agrees-and the Regulatory Position C.6 explicitly so states.
Comment 10:
Recommend revising to read (C.6) as follows:
L a.
The level of margin should be based on all the margins applied during the qualification process including:
(1) Methods, studies or analyses in determination of service environ-men':al conditions, (2) Equipment application, design and production quality control.
I (3) Test set-ups, (4) Choice of test parameters (i.e., values, sequences, combinations, and (5) Test procedures.
r b.
The' level of margin is adequate based on test margin alone if:
11/4/83 113 4AGGAR/A
(1) test margin is applied by increasing the' number of test cycles, extending the test duration or increasing the levels of testing by applying test margin to the environmental test paramters and (2) the suggested factors of IEEE-323-1974 are used.
Response
The Regulatory Position C.6 has been extensively revised to reflect the intent of this comment.
Comment 11:
NUREG-0588 and the 00R Guidelines allowed that no further margin need be added to the radiation requirements if the requirements were generated by one of those documents.
This paragraph appears to require an additional margin on radiation?
Response
If calculations are performed in accordance with the methodology described in Appendix 0 for development of radiation environments, no additional test margin is necessary due to the conservatism used.
Comment 12:
Besides the fact that the one-hour requirement is arbitrary, has NRC staff addressed the question as to whether this applies to radiation or only the steam / pressure / spray profiles? That is, is one extra hour of radiation required? Appendix C, paragraph 1, could be read as not requiring it.
Suggest rewording "For other eqJipment, operating 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> or longer, the 10 percent..."
11/4/83 114 4AGGAR/A
3
Response
See response to Comment 11 above.
C_omment 13:
IEEE 323-74 addresses margins in article 7 and figure 1 as well as in the section 6.3.1.5 referenced in this position.
Figure 1 of IEEE 323-74 shows a test profile with two initial transient spikes and with margins added to each peak and dwell of the profile.
The requirement for two initial transients is unrealistic and does not substantially contribute to safety in view of all the other margins provided.
Therefore this should not be a requirement.
- Further, the NRC should clarify if time margins are indeed to be added to each peak and dwell of the accident profile or only to the overall post-DBA period.
Note that item 6, section 6.1.3.5 of IEEE 323-74 requires the tirte margin only for j
the period following the DBA not during the DBA.
Response
One acceptable method for meeting the requirement for margins is to use the suggested margins as stated in IEEE 323-1974 (except time margins).
The lic.ensee has the option to justify any other method.
For example, IEEE 383-1974 calls for one cycle of exposure to the simulated environment followed by voltage withstood tests with the cable specimen coiled around a metal mandrel and immersed in tap water.
for time margins, reference should be made to the Revised Regulatory Position C.6.b.
Section C.6 b Comment 1:
The one hour requirement is unnecessarily excessive.
The IEEE 323-1974 10%
time margin should be used instead.
The minuscule increase in safety to the I
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public does ot justify the huge expense of providing equipment qualified for one hour when that equipment performs its safety function in seconds or milliseconds.
Devices that initiate scram and perform their safety function seconds after a design basis accident would be required to be qualified for a much harsher environment than cubjected tu when perfarming their safety function.
3 Comment 2:
The subject of a one-hour minimum qualification time has been an issue of centention between industry and the NRC since the initial publication of NUREG-0588.
In order to technically defend a minimum qualification time, we propose that the third sentence in Paragraph C.6.b be revised as follows:
"Equipment in these categories may be quali.fied for the time period of safety function performance (plus margin) but should not be considered qualified for applications requiring longer time periods (even at lower temperatures) unless the thermal timo constant of equipment can be shown to be equal to or less than one-tenth of the test period."
Comment 3:
The requirement that all equipment remala operational for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in excess of the accident analysis time in an accident environment is not realistic.
Equipment which is required to operate at the inception of an accident for short periods, say seconds or a few minumtes, should not carry a 1-hour margin capability. We agree that margin is necessary and that such definition as a percentage value becomes less and less meaningful as the required operational time shrinks.
It would appear more reasoraDie, however, to allow a 10-minute margin for equipment requiring nperation for short intervals following cccident initiation.
11/4/83 116 4AGGAR/A
o Comment 4:
We continue to be totally opposed to the arbitrary application of an additional one-hour time requirement in excess of the calculated worst-case time required to perform the safety function as derived from accident analysis.
Implementa-tion of this requirement will negate extensive qualification testing already completed by industry and, furthermore, will severely impact qualification test schedules established for the lead plants committed to IEEE 323-1974.
The Staff has indicated that this requirement has arisen from concerns over earlier transmitter tests where failure of some units was noted after a few minutes.
Thus, we recommend that the sentence, "Equipment in these categories should remain functional in the accident environment for a period for at least I hour in excess of the time assumed in the accident analysis",
be changad to:
"Equipment in these categories is required to remain operable in the accident environment for a period in excess of the time assumed in the accident analysis.
The equipment performance, after completing its safety function, shall be shown not to negate any prior completed automatic safety functions or, in the case of equipment required for post-accident monitoring, provide misleading information to the operator".
Comment.5:
The requirement for equipment to remain functional for a period of at least one hour beyond that calculated for the accident is arbitrary and excessive.
We recommend a 10 percent or 20 percent time margin be placed on such equipment in lieu of the one hour requirement.
Comment 6:
In Position C.6.b., the "one hour" margin requirement is unjustified and without adequate basis.
This one hour" margin requirement will only subject equipment to unnecessar.ily harsh testing and will not add to plant safety.
This entire position should be deleted.
s 11/4/83 117 4AGGAR/A
i Conment 7:
The position that equipment should remain functional in the accident environment for a period of at least i hr in excess of the time assumed in the accident analysis is technically unjustified and arbitrary.
It is also excessively conservative for equipment that performs its safety functions in a few seconds or minutes into an event.
All equipment should be qualified for the period of time it is required to be operational following the design basis events speci-fied in plant specific accident analyses, plus 10 percent margin, consistent with Section 6.3.1.5(6) of IEEE 323-1974.
This paragraph, as proposed, should be deleted in its entirety.
Comment 8:
The prescription that equipment required to perform its safety function less than 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> into a design basis accident should be qualified for a period of at least I hour in excess of the time it performs that function is arbitrary and technically unjustified.
It fails to give credit to the accident analysis that must be performed to identify the limiting accident conditions in compli-ance with both IEEE 323 and the equipment qualification rule, 10 CFR 50.49.
This accident analysis is subject to NRC review and evaluation.
The time to perform a device's safety function is not assumed in the accident analysis as stated in this section; it is determined.
(The analysis also assures that equipment not required to perform a safety function does not fail in a manner detrimental to plant safety.) Once the limiting time to function tid associated accident environments have been determined, adequate conservatism is assured by current practice including, (1) the 10 percent time margin suggested by IEEE 323, (2) the margins applied to other parameters (temperature, pressure, etc.) suggested by IEEE 323 and (3) the conservatisms built into the specifi-cation of accident conditions.
Comment 9:
i We recommend deleting paragraph C.6.b as IEEE Standard 323-1974 is adequate to address the operating time margin requirements.
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t
-b' s
Comment 10:
An arbitrary time margin of one hour to be added to the operability period of all equipment is too restrictive.
The use of a lesser margin for individual pieces of equipment should be permitted where adequate technical justification can be provided.
This comment was expressed many times in response to NUREG-0588 and the staff has previously indicated that certain exceptions to the one hour minimum operating time are permitted.
Specifically, the staff has indicated that plants subject to the DOR guidelines and NUREG-0538 Cate-gory II need not meet the one hour time margin if the equipment was tested prior to May 23, 1980 and subsequent failure will not be detrimental to plant safety. We believe that this flexibility should be applied to all equipment requiring environmental qualification, not just equipment subject to the 00R guidelines, or NUREG-0588 Category II.
Furthermore, the application of sound technical judgnent should be acceptable regardless of when the equipment was purchased.
Therefore, we suggest that the proposed Regulatory Guide be revised to permit the use of engineering analysis to justify the use of a time margin less than an arbitrary value of one hour.
Comment 11:
There is no technical basis to require a component to remain functional for an arbitrary "one hour" when such function is not required to maintain the integ-rity of the plant.
A shorter period, when justified, should be permitted.
1 Comment 12:
Rather than arbitrarily invoke the "one hour" requirement, why not address the real issue, i.e., the thermal time constant of the equipment? The following wording is suggested:
"For equipment with safety function times less than the duration of the event, qualification to the safety function time (based on system analysis) rather than event time is acceptable so long as such equipment is not subsequently applied and considered qualified for longer' times unless it 11/4/83 119 4AGGAR/A i
o i
can be shown that the equipment's thermal time constant was less than 0.1 x the period tested."
Comment 13:
Section C.6.b - The requirement that all categories of equipment should remain functional in the accident environment for a period of at least I hour in excess of the time assumed in the accident analysis is unduly conservative.
Many qualification parameters inherently include margin resulting from assump-tions used in calculating accident environments.
These margins, coupled with the recommended time margin of IEEE 323-1974, are sufficient to assure proper performance of short duration equipment, imposition of a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> requirement is unwarranted and would lead to significant cost impact with essentially no improvement in plant safety.
Comment 14:
We believe the arbitrary imposition of one hour, in addition to specific required operating time, has no basis.
Components which perform their function before experiencing any condition outside the normal / abnormal conditions should be exempted from environmental qualification requirements for devices in the "harsh environment." Only those requirements necessary for "mild environment" equipment should be imposed.
Components having operating times of less than 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> should still only have a justifiable margin added to the operating time (e.g., 10 percent of operating time) for qualification purposes.
Response (Comment 1 thru 14):
j The Regulatory Position C.6.b has been modified to reflect the industry concern.
Shorter margin less than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is acceptable if this could be technically justified.
The revised position provides the criteria for justification.
Comment 15:
Margiri is the term used to account for the uncertainties of production varia-tions and reasonable errors in defining environmental conditions and performance 11/4/83 120 4AGGAR/A
o e
requirements.
The IEEE Std. 323-1974 suggests a margin of 10 percent be added to operating time requirements and, for some equipment, this Section agrees with that amount of margin.
However, this Section states that "short time" equipment should be qualified for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in excess of the time assumed in the accident analysis.
"Short time" is defined in this Section as 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />; this is unreasonable.
Equipment whose function is to detect an abnormal event is designed to perform this function within a short period of time.
This short period of time may be only 500 milliseconds, which is 0.013 percent of an hour.
Also to add 10 percent to 500 milliseconds is as unreasonable as adding 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
What is necessary is a reasonable definition of "short time"for qualification testing requirements.
Another very important factor to be realized is the extreme difference in environmental conditions between 500 milliseconds and 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />.
Short time equipment may be able to be qualified for the environmental conditions present when it must operate and then remain in a safe condition, but it may not qualify in the environment which will exist at 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> into the accident.
It would be a great cost burden on the utility industry to be required to use this excessively conservative definition of 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> for "short time" and it will not enhance the safe operation of nuclear power plants.
Comment 16:
The introduction of an additional 10% time margin is unnecessary.
Installed equipment has been analyzed to previous requirements and found satisfactory.
This additional time margin would require retesting with no increased assurance of equipment performance.
Comment 17:
The imposition of this requirement is a backfit to those plants which are in compliance with the interim requirements documents.
The Staff in the Staff Clarification document, Issue 8, One Hour Minimum Operating Time, did not require this operating time margin for plants using the requiremerits of the 00R Guidelines or NUREG-0588 Category II, for equipment which was tested prior to May 23, 1980.
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e v
Response (Comment 15 thru 17):
.Requalification of equipment previously qualified is not required.
Also note that the Regulatory Position C.6.b has been extensively revised to reflect the industry concerns.
Section C.7 Comment 1:
If the NRC Staff does not intend to require any testing for any equipment in mild environment applications or, at least, does not require aging to be addressed in conjunction with seismic testing, this section should be identi-fied as applying to the qualification of equipment in harsh environment appli-cations only.
Comment 2:
In position C.7, paragraphs a. through h. apply to equipment required to function in a harsh environment only.
Change the first sentence in C.7 to read as follows (changed portion underlined):
"Section 6.3.3, "Aging," of IEEE Std. 323-1974 should be applied to equipment in a potentially harsh environment only and should be supple-mented with the following:"
Comment 3:
Section C 7, regarding aging, should be clarified to apply only to equipment located in a harsh environment.
Response (Comment 1 thru 3):
The revised Regulatory Position C.7 makes a reference to 10 CFR Part 50.49(e)(5).
The final rule does not apply to equipment located in mild environment and, l
11/4/83 122 4AGGAR/A
g -
a'
'I therefore, Regulatory Position C.7 does not apply to equipment located in mild environment.
For such equipment, the requirement for aging in-conjunction with seismic testing will be covered by RG 1.100.
Section C.7.a Comment 1:
It would be helpful to provide references to the ' identified synergistic effects".
Further, if the NRC concern has to do with testing, the IEEE 323-1974 reference should be to 6.3.2, Test Sequence.
Comment 2:
Some synergistic effects have been identified; however, they cannot adequately be quantified at this time.
This requirement appears premature until the final results from the NRC contractors at Sandia are available.
Comment 3:
At this time synergistic effects are a subject for research.
If there are known synergisms, they should be listed.
Comment 4:
The NRC should provide specific guidance on synergistic effects since the industry, in general, has not found that this is a significant issue of concern.
Any known synergistic effects as per NRC studies and data should be specifically referenced for use by industry.
Comment 5:
Regulatory Position C.7.a states that where synergistic effects have been identified, they should be accounted for in the qualification.
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P i
This provision imposes a requirement which we feel is not f'ully understood.
How'will test reports be reviewed for acceptability when considering synergis-tic effectal A qualification test and report done today would include known synergistic effects, however, the report may be reviewed in the future when additional synergistic effects are known.
Does this invalidate the qualifica-tion of installed equipment? The NRC ought to focus its resources and those of the industry on ensuring that equipment can withstand first-order effects.
Response (Comment 1 thru 5):
Only those synergistic effects which have been identified prior to the initia-tion of qualification should be accounted for.
Regulatory Position C.7.a has been modified accordingly.
Thus, this is not a "backfit" provision.
Comment 6:
This requirement, to consider synergistic effects, is a new requirement for equipment previously-reviewed under the provisions of the 00R Guidelines and NUREG-0588 Category II.
It is also a new requirement for all equipment quali-fied to the requirements of IEEE-323-1974 prior to the issuance of the NUREG-0588 Category I guidance.
It is inappropriate to require the consideration of second order effects when we do not have a thorough understanding of individual primary stress effects and their causal relationship to equipment performance.
Any general pursuit of these.second-order effects unless they are known to be significant will detract from the industry's focus on the other important aspects of environ-mental qualification.
Response
This is not a "back fit" requirement (See response to Comments 1-5.)
Also, the staff agrees that only known synergistic effects must be considered when these effects are believed to have significant effect on equipment performance.
This position is consistent with 10 CFR Part 50.49(e)(7).
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f Comment 7:
I believe it is necessary to be specific in this standard as to who or how the identification of synergistic effects is made when one needs to take it into account.
All sorts of specialized tests have shown contradictory synergistic effects and allegations have been tossed about very promiscuously as to when synergistic effects are important.
If the words "by anyone" were inserted after "identified" in this sentence, it would be tantamount to saying that one always has to account for synergistic effects.
Thus, clarification is certainly needed here.
Response
Only those synergistic effects which are reported in national publications and technical papers circulated in the United States should be considered.
Comment 8:
l The word "known" should be inserted before "where" and "synergistic" in line one.
Response
This is not necessary since NRC does not require that "unknown" synergistic effects be considered.
Comment 9:
To just consider "known" synergistic ef fects may be too weak.
In an extreme example, a designer should use a material about which he knows nothing.
It may be necessary to consider screening tests of some kind, at least in some cases.
i l
l
[
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a
Response
NRC does not recommend that applicants conduct individual screening tests to determine or identify synergistic effects.
We believe that the ongoing research program sponsored by NRC and the industry are sufficient to identify significant synergistic effects.
Comment 10:
The determination of synergistic effects should be more specific, since it is unreasonable to require all combinations and permutations of synergistic effects to be considered by the licensee.
Comment 11:
Since significant radiation-thermal synergisms have been found for a number of polymer materials, and since the existence or non-existence of synergisms for most materials is unknown since few appropriate experiments to look for said synergisms have been performed in the past, it is important to check for radiation-elevated-temperature synergisms on all materials for which literature references cannot be cited to specifically rule out such synergisms.
Since laboratory radiation aging experiments are carried out using radiation dose rates much higher than those experienced under plant conditions, and since the degradation of organic polymers can exhibit strong dose-rate depen-dent effects, is is important to investigate potential dose-rate dependency.
Response (Comment 10 and 11):
The Regulatory Position C.7.a has been revised to include the synergistic effects which are known today.
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"6 Section C.7.b Comment 1:
Several methods for thermal aging considerations are available without the need to result to a case-by-case basis if they are not based on Arrhenius methodology.
For example, the stress analysis methods of IEEE 650-1979 are supported by the NRC (IEB 79-01B Supplement 2).
Response
The staff believes that the Arrhenius methodology is acceptable for addressing accelerated thermal aging within the limitations of state-of-the art.
Any other methods must be justified and evaluated on a case-by-case basis.
Comment 2:
In Position C.7.b the last sentence reads (emphasis added), "Other aging methods that can be supported by tests will be evaluated on a case-by-case basis." The words, "...that can be supported by tests..." are overly restric-tive.
Even the Arrhenius methodology is not supported by tests except for a few very simple pieces of equipment and simple materials.
Other aging methods should be justified on their own merits.
It is recommended that the words
"...that can be supported by tests..." be deleted.
Response
The staff agrees.
The words as suggested, have been deleted.
Section C.7.c Comment 1:
Section C.7 endorses the "aging" requirement as identified in Section 6.3.3 of IEEE Std. 323-1974.
If the aging requirements are met, then there is no need 11/4/83 127 4AGGAR/A
s-to further identify "phase' changes and reactions" as a failure to qualify will identify this.
Comment 2:
Position-C.7.c., requires known material phase changes and reactions to be identified.
This requirement could be misinterpreted to mean that all known phase changes must be documented.
Such an interpretation would be an unjusti-fied requirement and would only generate paper but would not improve safety.
To eliminate this misinterpretation, rewrite the position as follows (changes underlined):
"Known material phase _ changes and reactions which occur within the extrapolation limits should be identified to ensure that no adverse changes occur."
Response (Comment 1 and 2):
Regulatory Position C.7.c has been deleted.
The sta'ff agrees with Comment 1 above.
Section C.7.d Comment:
i The requirement for aging acceleration rate and activation energies used during qualification testing is not required where aging is insignificant and t
analysis in lieu of testing is performed.
In fact the industry has determined
- hat aging impacts for equipment not subject to severe DBE environment changes are generally insignificant.
Response
i Regulatory Position C.7 does not apply to equipment located in a mila environment.
I 11/4/83 128 4AGGAR/A
9 Section C.7.e Comment 1:
Item C.7.e precludes the use of surveillance and inspection techniques as ongoing qualification methods.
We strongly disagree with this limitation.
Measurements can be made on in-service equipment which can quantify the extent of equipment and material in-service degradation.
These measurements can be correlated to (1) the level of pre-conditioning received during qualification testing, (2) material damagability limits established for the associated components or (3) manufacturer recommendations.
When this information is coupled with an understanding of the number, type and extent of the s2 vere environmental stresses encountered during hypothesized DBAs then technically justified decisions can be made which conclude that (1) the equipment will adequately perform for a defined additional period of time based on the existing component qualification information or that; (2) the equipment should be refurbished and certain parts replaced to assure adequate performance for a defined additional period of tim? or that; (3) the equipment has reached a level of degradation which requires its replacement.
For example, the following information pertaining to a 50V is available:
(1) the manufacturer has stated that the EPR body gasket material can acceptably perform after severe deterioration but that the gaskets must be replaced whenever the 50V is disassembled; (2) the EPR seat material can also adequately perform after degradation beyond the material's threshold; and (3) the testing performed by the manufacturer and the EPR vendor indicates that a 70% increase in material hardness is within the allowable degradation permitted for this seat material.
A licensee armed with this information may choose to periodically (during refueling) select for testing a sample of this style of 50V which is used in his plant.
For this selected sample the licensee disassembles and inspects the valve components and measures the change in hardness received by the seat material.
Existing testing or analysis show that the DBA stresses hypothesized l
l 11/4/83 129 4AGGAR/A
produce only a 5% increase in hardness.
Based upon this information, the licensee establishes a 60% increase in hardness as a threshold value to be used to determine replacement.
The additional. 5% (i.e., 70%-5%-60%) should allow sufficient margin to account for sampling inaccuracies and other assump-tions.
If the valves sampled showed that deterioration is well within the allowable range, then the licensee can conclude that all the valves of this style will continue to adequately perform until the next sampling test is performed.
In the interest of brevity, we have omitted many additional details, such as sample selections, associated with this example. We offer this discus-sion only as a typical example of the type of activities which address ongoing qualification and which should be' accepted by the Guide.
The performance of such sample activities in lieu of replacement of all such SOVs offers additional advantages.
For example, minimizing the disassembly, reassembly and replacement activities reduce the potential for errors which may occur as part of these operations.
As a result overall equipment relia-bility is increased.
In addition, the radiation exposure received by station personnel during such operations is significantly reduced.
One final aligned point related to in-service degradation, is that the potential for simultaneous redundant conmon-mode equipment failures due to such in-service degradations are highly unlikely since (1) no two manufactured components are identical, (2) there are significant differences in the in-service stresses which occur at each component due to their physical separation and operational variances, and (3) component replacement, preventative maintenance and other activities do not occur at the same time.
These effects, and other, result in "built-in" equipment diversity which renders highly unlikely multiple simul-taneous failures.
Comment 2:
Periodic surveillance testing or other methods should be acceptable to address aging if they are justified.
t 11/4/83 130 4AGGAR/A
n
- - =. - -
Comment 3:
This section (Section C.7.e) does not clarify the NRC position, which, we understand, accepts and endorses the use of surveillance testing of inplant components to extend component qualified life.
The surveillance testing can detect degradation, from the original condition, without subjecting equipment to the limiting service and environmental conditions.
Pass /f411 criteria can then determine if the equipment should be replaced.
This point should be clarified.
Response (Comment 1thru_3J:
The staff has deleted Regulatory Position C.7.e.
The requirements for "aging" are explicitly stated in 10 CFR Part 50.49(e)(5).
Surveillance and inspection techniques can be regarded as on going qualification methods.
Section C.7.f Comment 1:
Humidity aging is generally beyond the state-of-the art in accelerated aging programs.
Comment 2:
The aging effects of humidity are not generally known and acceleration of unknown effects is not possible.
This paragraph should be deleted.
Comment 3:
Humidity aging is beyond the state-of-the-art, delete.
Humidity effects should only be considered as one of the environmental parameters.
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iE Comment 4:
There is no known way to accelerate the effects of relative humidity.
This should be a subject for research.
Comment 5:
The humidity effects on accelerated aging are hard to determine.
At best, the effects of humidity can be introduced during the thermal aging cycle, but the total effect of humidity aging is beyond the state of the art technology.
Comment 6:
The NRC should identify and endorse standards or references which define acceptable methods of accelerating humidity effects.
Comment 7:
No physicist I have met knows how to accelerate humidity aging effects.
This requirement therefore appears to ask for a demonstration which is beyond the state of the art.
Comment 8:
Item C.7 f requires humidity effects to be considered during accelerated aging. We are unaware of any technologies which presently exist to accelerate any aging effects of humidity.
Comment 9:
This section states that humidity effects should be included in accelerated aging.
It is not clear what is intended by this requirement.
Generally, components are aged in temperature, humidity controlled chamber; and are subjected to the 11/4/83 132 4AGGAR/A
6 accident environment (100%-RH) during HELB or LOCA testing.
Cyclic effects of humidity are generally not considered in qualification testing.
Qualification of equipment for humidity is a best state of the art technology.
There are no detailed standards for how this type of testing should be performed.
Until reasonable standards are developed for humidity consideration and testing, humidity should not be addressed by this regulatory guide.
Response (Comment 1 thru 9):
The Regulatory Position C.7.f has been deleted.
The staff agrees with the comments on this issue.
Comment 10:
Paragraph C.7.f appears to be requiring an expansion of the state of the art in accelerated aging.
We know of no way to accumulate 40 years of humidity exposure into a practical time period.
Comment 11:
It should be noted that the inclusion of humidity effects in the accelerat9d aging of equipment is very difficult and for which there is little theoretical basis available today.
Humidity is an example where an acceleration model (such as the Arrhenius equation for thermal aging) does not exist.
In actual service it is expected that any adverse effects due to humidity would be gradual and readily detectable by periodic maintenance / testing and surveillance programs.
Therefore, it is suggested that this section be revised to state that the humidity effects on equipment should be evaluated, and where it has been determined that the effects are not negligible, a surveillance program should 1
be established to monitor and track the extent of the effects.
1 i
11/4/83 133 4AGGAR/A
Comment 12:
The use of an example where relatite humidity effects are negligible such as cable insulation would be infort ive.
Response (Comment 10 thru 12) i See response to Comments 1 thru 9 (page 133).
The staff recognizes that an adequate program of preventive maintenance and surveillance should be estab-lished to insure the ability of the equipment to perform its safety function.
Sections C.7.g and C.7.h Comment 1:
In Position C.7.g. & h. the term qualified life should be discussed as an estimate.
The present discussions in both IEEE Std. 323-1974 and the guide imply that qualified life is a fixed number based on rigorous calculations.
Indeed, this is not true.
Even the Arrhenius methodology has a significant amount of uncertainty (especially for complex electrical equipment).
At best, a qualified life is a conservative estimate of a minimum qualified life.
In order to avoid the misinterpretation that qualified life is a firm, rigorously determined number, it is recommended that qualified life be referred to as f
"estimated qualified life" throughout the regulatory guide, Comment 2:
Establishing life on the "basis of the severity of the testing performed, the conservatisms employed in the extrapolation of data, the operating history
..." may lead to misunderstandings regarding the definition of "severity."
It must be noted that the severity is inherent in the basic methodology even when the test profile exactly matches the required profile.
For example, the typical air-oven testing of electric cable insulatio. material in lieu of completed cable assemblies (i.e. the insulation typically isolated from air by t
l 11/4/83 134 4AGGAR/A n.,
the inner conductor or outer jacket) is extremely conservative as the change in physical properties (e.g. tensile strength or elongation) is significantly increased in an oxygen rich test-oven environment.
Furthermore, the as installed cable (as well as all motors and other electrical 2
coils) operating temperature is due to the self-heating (I R) of the current carrying conductor with the inner insulation surface limited to the total allowable temperature of the specific insulation while the outer surface is expected to be 10-15*C cooler.
In addition, the actual current which the cabling (or motor winding) carries is a function of the electrical load which is seldom at the nameplate rating (e.g., a pump maximum break horsepower may be 75 bhp while the nameplate rating of the motor drive is 125 hp) resulting is a significant reduction in operating temperature as the operating tempera-ture is a function of the square of the operating current.
Actual field experience has demonstrated that the standard IEEE methodology of accelerated thermal aging of insulating systems is conservative.
Data cer:e-lating IEEE Std 259, "Standard Test Procedure For Evaluation of Insulation for Specialty Transformers" and field data demonstrated the use of IEEE standard methodology is conservative.
Comment 3:
Regulatory Positions C.7.g and h require the definition of a qualified life for all safety-related electrical equipment (subject to the exclusion of l
equipment in mild environments).
We share the perspectives of the major industry research organizations involved in accelerated aging investigations which have stated that the use of accelerated aging to riefine equipment quali-fied life is beyond the defendable state-of-the-art.
The research done to date points to one irrefutable conclusion:
Accelerating aging cannot be used as a technique to predict, with any accuracy, the quali-fled life of any but the simplest equipment.
In sum, the use of accelerated aging models to define a qualified life, as the Staff proposes, is not techni-cally feasible.
11/4/83 135 4AGGAR/A
Comment 4:
It is recognized that a strict determination and demonstration of qualified life is impractical.
However, an estimate of expected life of equipment can
~be based on prestressing where considered meaningful (e.g., thermal, radiation, l
cycling).
The basis for the estimated life should be clearly documented.
Comment 5:
Theoretically, these accelerated aging and qualified life concepts appear logical.
In practice, however, research more importantly testing experience have shown that using accelerated aging to predict an accurate "qualified life" is beyond the state of the art.
Sandia Labs, the principal NRC research consultant regarding environmental qualification has stated in a recent report that:
"While conceptually appropriate, aging to a specific long-term end-of-qualified-life condition is beyond the existing state-of-the-art, parti-cularly for complex equipment.
Unfortunately, this was recognized only after adoption of IEEE 323-1974 by the industry and by the Nuclear Regulatory Commission, which naturally demanded adherence by the industry to an industry-adopted position."
and further, "Too far, too fast, too specific seems to summarize the historical l
experience; a universal unwillingness to state and defend the state-of-the-art may be the root cause."
The Electric Power Research Institute (EPRI), Franklin Research Center, have
~
similarly stated in a recent research report:
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tr -
"The main conclusion of this work is that, with the possible exception of certain simple materials, the prediction of a qualified life through accelerated aging is generally not feasible at the present time."
and further th6t
"...the demonstration of a qualified life through accelerated aging is generally not feasible.
(This conclusion is supported by a fairly sub-stantial military effort in the 1960's to assess the usefelness of accelerated aging as a basis for predicting long-term eouipment performance.)"
and finally "The known mode, including those of considerable mathematical sophistica-tion, are rather simple approximations of the real-life problem; sufficient correlation with observed real-time aging to substantiate their validity for long periods of time is lacking."
Based on the above discussion, we strongly recommend that the Guide be revised to delete any reference to qualified life since the present state of the art cannot technically support this concept.
A more appropriate approach is to require that qualification test programs address significant aging mechanisms by natural or artificial aging techniques only if the techniques are not practicable or technically meaningful, then a surveillance and preventative maintenance program to assess and correct in-service degradation should be acceptable provided it is based on the equipment's known susceptibility to aging degradation, the results of inspections, and/or manufacturer's recommendations.
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8x a
Comment 6:
Qualified life is not established on the basis of test severity but rather on aging validity.
Comment 7:
We feel that the requirement stated in Section e(5) of 10 CFR 50.49 (i.e.,
the equipment must be replaced at the end of its qualified life unless ongoing qualification of prototype equipment naturally aged in plant service shows, by artificial aging and type testing, that the item has additional qualified life) is overly restrictive if taken literally.
We feel that Para-graph C.7 of the proposed Reg Guide revision should be modified to allow compliance to this requirement by using:
(1) component replacement as a means of extending qualified life (e.g., change seals and elastomers every five years); (2) redefintion of qualified life based on better analysis or advance in the "state of the art"; and (3) extending qualified life based on retesting with equipment that had been artificially aged only (as opposed to natural age in p?%nt service) to a longer life.
Response (Comment 1 thru 7):
After considerable delibrations and discussions with the industry, the staff has decided to delete Regulatory Positions C,7.g and C.7.h, which make reference to qualified life.
The objective of aging is to put test samples in a condition equivalent to the end-of-life condition.
If preconditioning to an end-of-installed life condition is not practicable, the equipment may be preconditioned to a shorter designated life.
The equipment must be replaced or refurbished at the end of this designated life unless ongoing qualification demonstrates that the item has additional life.
This staff position is consistent with 10 CFR Part 50.49(e)(5).
11/4/83 138 4AGGAR/A
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Section C.7.1 Comment 1:
Section C.7.1 should be deleted from the guide until such time as criteria for assessing age-related failure can be identified.
Comment 2:
Maintenance does.not generally identify age-related degradations as implied in
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this section.
Response (Comment 1 and 2):
i Regulatory Position C.7.1 has been deleted, since this is outside.the scope of this Guide.
An on going maintenance / surveillance program is essential to maintain equipment in a "qualified condition." This is a QA requirement and is addressed in RG 1.33 which endorses ANS 3.2/ ANSI N18.7-1976.
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Section C.8 Comment 1:
We'do not believe the Staff should impose any arbitrary restrictions on the-use of operating experience or analysis in conjunction with qualification.
programs and, furthermore, believes this paragraph is redundant to paragraph C3, We,-therefore, recommend total deletion of this paragraph.
P Comment 2:
The restriction on the use of well-supported analysis or operating experience for qualification to cases where testing is precluded by the state-of-the-art or physical size of equipment is not justified.
It is recommended that the i
last two sentences be deleted.
Comment 3:
Recommend deleting last two sentences of paragraph commencing with:
"Operating experience and analysis...."
We believe there is not sufficient technical justification for the indicated restrictions which are also inconsistent with the interim guidelines.
Comment 4:
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The prohibition / minimization of analysis to demonstrate equipment qualifications is a fundamental flaw in logic of achieving confidence in equipment performance.
The environment parameters to which the equipment is qualified / tested are the results of analyses, so to prohibit analysis of the performance of equipment with respect to calculated environment's is inconsistent, j
6/16/83 140 5AGGAR/A I
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i Comment 5:
This position deals with the same aspect dealt with by regulatory position 3.
Therefore regulatory position 8 should be incorporated into regulatory position 3.
Regulatory position 3 should then address sections 5, and 6.4 of IEEE 323-74.
Comment 6:
The third sentence of this section implies that operating experience and f
analysis based on test data may not be used unless testing is precluded by e
equipment size.
If in fact evaluation of these methods performed in response to the second sentence of this section shows their adequacy, then operating experience or analysis should be acceptable.
Comment 7:
There should be no limitation on the proper use of analysis, i
Comment 8:
i This position includes an unreasonable restriction on use of operating experience and analysis, in lieu of testing.
Specifically, testing is precluded only by I
the physical size or the state-of-the-art (of testing) according to the third sentence in this position.
There are many other considerations that are valid in a decision to test or analyze.
For example, one may wish to do an analysis based on equipment which is larger than that to be qualified, but was previously tested.
Economics and careful engineering judgment should prevail in such cases. Operating experience should never be rejected out of hand.
It should be encouraged rather than discouraged by NRC as a valid approach when properly
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executed.
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'e Response (Comment 1 thru 8):
The staff agrees that this regulatory position C.8 is redundant to regulatory position C.3_and therefore, agrees to delete C.8.
The methods of qualification acceptable to NRC are explicitly stated in 10 CFR Part 50.49(f).
Section C.9 t
Comment 1:
The words 'same design' should be deleted from the first sentence of this positon and replaced with "identical design and materials."
Comment 2:
Recommend changing the word "same" in the first two sentences to the word eouivalent.
Comment 3:
1 Change the term "the same" to "equivalent" throughout the section.
Comment 4:
The term "same design" can be subjected to different interpretations.
For l
example, the substitution of 316 Stainless Steel for 304 Stainless Steel
. should not require requalfication testing, rather a simple analysis, f
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13 Comment 5:
Does "components of the same design" mean "identical components?"
If not, why not?
Comment 6:
The overall response of a component to aging mechanisms, adverse environments, and seismic events is highly dependent on the size, materials and design of the component.
As a consequence, we recommend the term "may be replaced with components of the same design" be revised to read "may be replaced by components that can be designed and manufactured to the same design, performance and material specification."
I Comment 7:
l This proposed revision does not define the meaning of the word "same."
We propose that the first sentence in Paragraph C.9 be revised, following the word "components," with:
"...that are equal to or better than the component i
replaced." A certification from the manufacturer that the component is equal to or better than components previously provided will suffice.
In the absence of a certificate, an evaluation must be made to ascertain whether or not any variations exist which affect the safety related function of the component.
Response (Comment I thru 7):
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The replacement equipment must be upgraded unless there are sound reasons to the contrary.
The typical "sound reasons" acceptable to NRC have been included in the revised Regulatory Guide Position C.8.
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o Comment 8:
f The words in the last sentenet 'the replacement component should be designed to meet the performance requirements and should be qualified to meet the service condition specified for the original couponents' need to be clarified.
The word 'qualificd' implies performing IEEE-323-1974 type tests on discrete parts of subassemblies (e.g., motor starter, electronics modules, resistors, etc.) which is not pract! cal or meaningful when not tested with the whole assembly (e.g., Fotor Control Center, Logic Cabinet, transmitter, etc.).
This wurding should requite only that parts be bought to the same specification as the original part of the subassembly.
Response
The components that are gart of equipment qualified as an assembly may be replaced with the components of identical design.
This position is included in the revised Regulatory Position C.8.
Section C.10 Comment 1:
Paragraph C.10 says, "A certificate of performance by itself is not acceptable "
while Paragraph C.5.a says, "A certificate of compliance..
will generally be acceptable." This discontinuity needs to be resolved.
We believe that the NRC should provide guidance on what would be an acceptable content of a certi-ficate of compliance because such a certificate would be of benefit both to industry and the NRC in this area.
6/16/83 144 SAGGAR/A
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f comment 2:
i Section C.S.a states that for equipment installed in a mild environment, a f
certificate of compliance based on test data and analysis is acceptable.
This Section states that information on the qualification program is necessary.
l There seems to be a contradiction here, t
Comment 3:
Specific requirements for certificates of conformance to include test data i
does not recognize the real-world situation wherein data is considered proprietary and not made available to the utility.
Imposing a requirement to have all the data in a utility Central File may be unrealistic and unattainable.
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, Comment 4:
This section does not distinguish between the documentation required for equipment in a mild environment (see C.5.a) and equipment in other (harsh) environments.
Also, the "certificate of compliance" in C.5.a apparently refers l
to the same certificate as the "certificate of conformance" in C.10.
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This regulatory position requires that qualificLtion information accompany any F
certificate of compliance is in conflict with Item C.5.a.
Item C.S.a did not 6
require that such technical data accompany the manufacturer's certificate of compliance for mild environment equipment.
Furthermore, this sentence (pres-ently limited to test data) should be modified to encompass analysis and experience data.
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Comment 5:
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Section C.10 should be revised to distinguish between the differences in the documentation requirements for equipment subjected to harsh environmental conditions and those requirements for mild environment equipment.
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Response (Comment 1 thru 5):
This paragraph does not apply to equipment located in a mild environment.
L Comment 6:
Recommend revising section to read as follows:
"10.a.
For equipment located in a potentially harsh environment, in addition to the requiremnt of Section 8, "Documentation," of IEEE Std 323-1974, documen-tation should address the information identified in Appendix 0 to this guide.
6 A certificate of conformance is not acceptable unless it is accompanied by information on the qualification program.
A record of the qualification should be maintained in a central file to permit verification that each item 7
is qualified to perform its safety function under its postulated environmental l
conditions throughout its installed life".
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Response
I The staff agrees with the revisions suggested in the last sentence, and the regulatory position has been modified accordingly.
Comment 7-i i
For equipment subject only to mild environments, qualification is adequately i
documented through retention of certificates of conformance and purchase f
documents,
Response
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I See response to Comment 1 thru 5 (page 146).
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11/4/83 146 5AGGAR/A
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Comment 8:
Section 8 of IEEE 323-1974 required that documentation be maintained in an auditable form, however, not necessarily in a central file. We suggest that the requirement of a central file be relaxed to the extent that the maintenance of auditable records be sufficient to meet the documentation requirements for all utilities, Comment 9:
This paragraph should be completely rewritten to recognize the different documentation requiremerits appropriate to equipment in harsh, as against mild, environment applications proposed in paragraph C,5,a.
NRC should permit the licensee to retain summary information reports for equipment qualification, where the complete documentation is retained by the NSSS vendor.
In this particular case, in lieu of maintaining detailed proprietary information in the licensees central file, the licensee retains certification from the NSSS vendor of the applicability of the vendor qualification program and documenta-tion and verifies the certification by review, audits and inspection of the NSSS vendor's proprietary information which forms the basis of the certification.
Response (Comment 8 and 9):
The requirement for a central fils has been deleted.
Comment 10:
This regulatory position imposes new documentation requirements upon licensees who previously determined environmental qualification compliance using the guidance of DOR Guidelines or NUREG-0588, Category 11.
These interim requirement documents did not require documentation in accordance with IEEE-323-1974, nor 11/4/83 147 5AGGAR/A
1 did the 00R Guidelines require that information be compiled and presented in the form suggested by this Guide's Appendix 0.
Response
For older plants, which are required to meet 00R Guidelines or NUREG 0588 (Category !!), Appendix 0 (renumbered Appendix E) is optional.
D. Impimentatf or}
Comment 1:
What is the justification for these provisons.
Comment 2:
The implementation of this regulatory guide would be applicable to all equipment purchased after May 23, 1980.
This position is unreasonable as the guide contains requiremnts and positions that have been added, changed, or reflect added understanding which were a direct result of work that has taken place j
since May 23, 1980.
The implementation date of this regulatory guide would I
more appropriately be the date of its final issuance with the interim period covered by the direction and information available at the point in time when the work was initiated.
l Comment 3:
We endorse the Staff's intent to implement the guide in a manner that permits some relaxation for earlier plants.
However, the permitted variations identified in Section 0 still leave a significant ratchet for operating plants with 1
11/4/83 148 SAGGAR/A
e respect to the requirements they have been recently addressing under IE Bullet.in 70-01B.
Thus we recommend that for operating plants the Staff accept meeting tne requirements of the previously issued 00R Guidelines, IE Bulletin 79-01B and supplements, or NUREG-0588 as satisfying the intent of this revision to the Regulatory Guide.
Comment 4:
As this revision of Reg Guide 1.89 is intenced to clarify the requirments of the amendment to 10 CFR Part 50, it is imperative to clarify in this guide that the evaluations already completed by licensees and reviewed by the staff are still acceptable to the NRC.
This would be consistent with item 3 of the draft Value/ Impact Statement for this proposed revision.
Therefore, we recommend adding a sentence at the end of paragraph as follows:
"Equipment qualified to the requirements of the interim guidelines; i.e., D0R Guidelines, IE Bulletin 79-01B and supplements, NUREG-0588, satisfy the requirments of this Regulatory Guide."
Comment 5:
No reference in the imp 1 ment-i n section is made to the work performed in order to comply to the int' requirements.
Since this new guide is intended to reflect current practices, an implementation paragraph should be added that recognizes that work performed or agreements made under the interim guidance is still valid and acceptable. The DRAFT VALUE/ IMPACT STATEMENT implies that this is the intent of the proposed revision to this regulatory guide, but to avoid any confusion in the future, this intent should be explicitly stated in Section D. IMPLEMENTATION.
Comment 6:
This revised Regulatory Guide, as well as 10 CFR 50.49, should recognize the previans submittals made by licensees / applicants pursuant to IE Bulletin 79-018/NUREG-0588 and appropriately "grandfather" such cases.
If NRC intentions 11/4/83 149 SAGGAR/A
s are to otherwise require additional submittals of information for some elements, those requirements should be clarified.
Exemptions other than those given in D.1 - 0.3 were also granted to operating plants and NT0Ls for other elements of environmental qualification such as "harsh" versus "mild" documentation requirements, margin, accident analysis codes, etc. Reference should be made to 79-01B or NUREG-0588 requirements on all plants notwithstanding any previous submittals.
Comment 7:
We recommend adding a sentence at the end of paragraph D.1 as follows:
"Equipment
. qualified to the interim requirements; i.e., 00R Guidelines, IE Bulletin 79-01B and sucolements, NUREG-0588, are not subject to the provisions of this Regulatory Guide." This revision of R.G. 1.89 is intended to describe methods acceptable to meet the requirments of the amendment to 10 CFR Part 50.
It is imperative to clarify in this guide that the already completed evaluations are acceptable to the NRC.
This clarification is in accordance with item 3 of the draft Value/ Impact Statement for this proposed Regulatory Guide 1.89 revision.
Comment 8:
We strongly recommend that Section D (Implementation) of this Guide be-revised to clearly state that the equipment previously qualified in accordance with the 00R Guidelinei or NUREG 0588, Category II satisfy the requirements of this Guide.
Comment 9:
This proposed revision indicates various levels of qualification depending on the vintage of the plant.
The proposed rule should reflect this.
- Also, allowing for equipment to be qualified for radiation and chemical spray by analysis implies other requirements such as using the same piece of equipment 11/4/83 150 SAGGAR/A
y in test sequence, addressing aging effects, etc. need not be considered.
The format used in NUREG-0588 is recommended to clearly differentiate the requirements for the various plants.
Comment 10:
This section imposes substantial burden on utilities that have qualified equipment to the interim requirements (i.e, IE Bulletin 79-01B and Supplements, 00R Guidelines, NUREG-0588, and/or Staff Clarifications).
New requirements for recalculation of containment profiles and radiation doses, application of margin, listing, and qualification of mild environment equipment are now imposed by this section as written.
It is strongly recommended that this section be rewritten to state that equipment previously purchased or qualified to the interim requirements comply with this Regulatory Guide.
Comment 11:
We believe Regulatory Guide 1.89, Proposed Revision 1, does not give sufficient description of the requirements as stated in the ' Guidelines for Evaluating Environment Qualification of Class 1E Equipment in Operating Reactors' cr the Category II requirements of NUREG-0588 such that it can replace these documents as requirements which were mandated by the NRC memorandum and order CLI-80-21.
Therefore, either the regulatory guide should address only plants committed to Regulatory Guide 1.89 Rev. O and/or IEEE-323-1974 or the specific requirements for each group of plants (those required to meet 00R Guidelines, those required to meet NUREG-0588 Category II, and those required to meet NUREG-0588 Category I) should be included into the regulatory guide revision.
Comment 12:
The proposed regulation and revision to this regulatory guide should include provisions for acceptance of present operating license agreements.
11/4/83 151 SAGGAR/A
Comment 13:
The implementation positions in this Reg Guide seem to be somewhat different than previous NRC statments in NUREG-0588 and supplements to IE 79-018.
For example: (1) plants which originally committed to 323-1971 can qualify aging by analysis (but not radiation); (2) plants originally committed to existing industry practices can qualify radiation, spray, aging by analysis (but not temperature, pressure, steam); (3) operatig plants can use separate effects tests, apparently without regard to commitments to qualification; (4) plants which committed to R.G. 1.73 and R.G. 1.40 must pre-age valve operators and motors irrespective of other commitments (even thoJgh the R.G.'s only apply to equipment inside containment and R.G. 1.40 only applies to continuous duty motors inside containment, and the aging requirements of R.G. 1.73 are not considered adequate to today's standards), thus valve operators and motors outside containment get ratcheted because the utility committed to Reg Guides for equipment inside containment; (5) noncontinuous motors (regardless of location) get ratcheted because the utility committed to a Reg Guide for continuous motors; and (6) valve operators inside containment, which may even meet R.G. 1.73, get ratcheted because the utility committed to R.G. 1.73.
These inconsistenceies need to be resolved before the revised Reg Guide is implemented.
Response (Comment 1 thru 13)
The staff generally agrees.
See revised Implementation Section 0.1.
Section D.1 Comment 1:
Humidity should be included with radiation and chemical sprays as an "other service" condition for which qualification of equipment may be established by analysis.
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Response
Regulatory Position D1 has been deleted.
Analysis in combination with partial type test data that supports the analytical assumptions and conclusions, is acceptable.
However, NRC prefers testing.
Section D.3 Comment 1:
The implementation statement implies any device containing identified susceptible materials must have a demonstrated qualified life which implies an IEEE-323-1974 test to determine qualified life.
We suggest this should be changed to allow the identification of these devices and an analysis to determine replacement intervals based on the known susceptible materials life under the given conditions.
Comment 2:
The use of the term "Significant degradation" is too vague.
We would recommend changing the wording to "... susceptible to age induced degradation such that they can no longer perform their designed function." Alternatively the list of susceptible materials from 79-01B, Appendix C, could be included as an appendix to RG 1.89.
Response (Comment 1 and 2):
Section D3 has been deleted.
Section 01 has been revised to explicitly state the applicability of this Regulatory Guide.
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4 Section D.4-Comment 1:
For consistency, we suggest that the first sentence in Paregrph D.4 be reworded as follows:
"Replacement equipment used to provide spare parts or replace currently installed equipment should be qualified according to this guide unless there are sound reasons to the contrary." After the last sentence in this paragraph, we suggest the following addition:
' Replacement components (used in the assembly of equipment) should be provided as stated in Paragraph C.9.
In Paragraph D.4, we interpret the phrase "this guide" as referring to all of the language of the guide, including the exemption of operating plants from sequence testing in Paragraph D.2, We realize this exemption may not have been intended in the context of Paragraph D.4, and we suggest clarification.
Also in Paragraph D.4, we do not understand the significance of the word "prototype" in the second sentence.
This wording is different from the wording of this paragraph in previous drafts of this revision to this Regulatory Guide.
It should be noted that the existence of a commercially available device does not assure the existence of a prototype.
We recommend removal of the word "prototype".
Comment 2:
Implementation item D.4 should refer to the issue date of this regulatory guide or to the approval date for Section 50.49 of 10 CFR Part 50. and not to May 23, 1980.
Comment 3:
The position concerning replacement components appears to be in conflict with the position indicated in C9.
The NRC should indicate that replacement with 11/4/83 154 SAGGAR/A
r a component that is essentially identical to the original qualified component
- and which meets the traceability requirements of SECY-81-119, meets the intent
- of this revision to the guide. -Qualification to this guide should only be required where the replacement component or equipment is significantly different to the original.
Comment 4:
The Commission's Memorandum and Order (CLI-80-21) of May 23, 1980 required that.
IEEE Standard 323-1974 be applied to replacement parts in operating plants.
Equipment purchased after May 23, 1980 but before the effective date of this Regulatory Guide revision could not be ~ qualified according to the provisions of this Regulatory Guide.
tioreover, this Regulatory Guide takes many important exceptions to IEEE 323-1974, contrary to the intent of the Commission's Memorandum and Order.
Therefore, a sound reason exists for exempting from the provisions of this Guide replacement parts in stock or purchased "prior to the effective date of this Guide".
Comment 5:
We recommend deleting from the second sentence of paragraph D.4 the following phrase:
"or was purchased prior to May 23, 1980".
There is no technical justification for eliminating the use of analysis supported by test data as a means of demonstrating qualification beyond a given cutoff date.
Comment 6:
The date given (May 23, 1980) should be changed to some date later than the active guide.
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.s Comment 7:
The May 23, 1980 date should not be implemented.
The unavailability of prototype equipment or having been an item in stock should be sufficient reasons for not requalifying per the new requirements.
Comment 8:
This statement is not understandable in light of the implementation statements of 01 through D3 and position C3 (last sentence).
It appears that this could be deleted since the guide covers all operating plants and plants-under construction.
Response (Comment 1 thru 8):
The requirements for replacement equipment have been' explicitly included in Regulatory Position-C.8.
Regulatory Position C.8.c states the conditions which reflect sound reasons why qualifications need not be upgraded.
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'i Appendix A Comment 1:
Section C.1 refers to this appendix as "Typical Essential Equipment...". Also, Regulatory Guide 1.97 does not list the Post Accident Sampling and Monitoring equipment as accident mitigation equipment.
Response
Appendix A lists the typical equipment and systems covered by Regulatory Guide 1.89.
Certain post-accident monitoring equipment is covered by this Guide and is, therefore, included in Appendix A.
The title of the Appendix A has been modified.
Comment 2:
Change the title from "Typical Equipment or Functions for Accident Mitigation" to "Typical Safety Equipment or Safety Functions" as much more than accident mitigation functions are served.
Furthennore, this listing is inconsistent with guidance previously provided to industry.
The listing should review and consolidate the generic NRC listing of "Six Safety Functions" presented at the July 7-10 public meetings, the "Typical Equipment / Functions Needed for Mitigation of a LOCA or MSLB Accident" of Appendix A of "Guidelines for Evaluating Environmental Qualification of Class IE Electrical Equipment In Operating Reactors" (Enclosure 4 of IEB 79-01B), the "Plant Safety Functions" of NRC Regulatory Guide 1.97 Rev. 2, draft 10 CFR 50.49 (dated 6/17/81), and "Safety Functions" or "Safety Systen Functions" identified in various IEEE (IEEE 279, 323, 308, 603, etc.), or ANSI /ANS Standards (e.g., ANSI /ANS-4.5-1980, "Criteria for Accident Monitoring Functions in Light-Water-Cooled Reactors").
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Response
g.
The-title of Appen'ix A'is modified to read, "Typical. Equipment or Systems d
Import' ant to Safety."
Comment 3:
Note 1 of Appendix A states that equipment required to achieve cold shutdown must be considered as part of the essential equipment for accident mitigation.
We recommend that this note be changed to reflect the fact that the licensing basis of many plants is to a hot shutdown condition, not to cold shutdown as is implied.
A regulatory guide is not the appropriate vehicle to impose such.
a significant change to licensees.
Resconse:
Note 1 has been deleted.
Equipment reqeired to achieve cold shutdown is not covered by the Regulatory Guide.
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a APPENDIX D Comment 1:
This section states that the assumption of 50% of core inventory of iodine released and 95.5% of this remaining as elemental iodine are consistent with Regulatory Guides 1.3 and 1.4.
This is in apparent conflict with the following quote from these Guides:
"Twenty-five percent of the equilibrium radioactive iodine inventory developed from maximum full power operation of the core should be assumed to be immediately available for leakage from the primary reactor containment.
Ninety-one percent of this 25 percent is to be assumed to be in the form of elemental iodine..."
Over and above this apparent conflict is the fact mentioned in the last paragraph of Appendix C.1, that current thinking is that most of the iodine will be present as iodine and have the chemical behavior of this species.
NUREG-0771 ("Regulatory Impact of Nuclear Reactor Accident Source Term Assump-tions") and NUREG-0772 ("Technical Bases for Estimating Fission Product Behavior During LWR Accidents") conclude that "the dominant chemical form of iodine released to the containment for most light water reactor (LWR) accident sequences would be cesium iodide (CsI) not elemental iodine (1 )" (Summary of 2
We recommend to delete Appendix C and associated paragraphs in Section C.4.c, or delay issuing the proposed guide until current research efforts in the source term area are incorporated, as suggested in the last paragraph of Appendix C.1.
Any revision of source term requirements would, of course, be subject to industry comment.
Comment 2:
Regulatory position C.4.c 1 states that 50 percent of the core activity inventory of halogens is instantaneously released to the containment atmosphere (i.e. drywell atmosphere for BWRs).
Subsequent pressure buildup within the drywell due to the design basis event blowdown will result in the total drywell free air mass being forced through the suppression pool.
Therefore, the 11/4/83 159 5AGGAR/A I
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elemental and particulate iodine associated with the total 50 percent core releas'e would be reduced by the decontaaination factor of 10.
Clarification is required to substantiate the above interpretation or to propose an alternate distribution of the iodine among the liquid phase of the blowdown, and the free air volume of the containment.
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Comment 3 We feel the assumption in item 14 of Section 2.1 of Appendix C of 2% organic iodide and 95.5% elemental iodine may be consistent with R. G. 1.3 and R.
G. 1.4; however, since the NRC is factoring in the experience of TMI relative to Cs release, they should also factor in essentially 100% of the iodine found at TMI was CsI, which exhibits substantially different removal characteristics than elemental iodine.
Response (Comment 1 thru 3)
The wording in the Appendix has been modified to be identical to the iodine species distribution described by Regulatory Guides 1.5 and 1.4. The staff notes that additional research is occurring in the source term area and that a new iodine species distribution may be defined. If this is the case, appropriate revisions to this regulatory guide will be necessary.
Also see response to Comments 1-19 (Page 47) for the resolution of the cesium source term.
Comment 4:
Appendix D Section 2.1, Item 15, deals with PWRs.
However, if the same j
assumption has been made for the BWR, it is technically incorrect to assume zero leakage to the environment for equipment qualification while the tech spec leakage rate is assumed for offsite dose consequences.
It is, therefore 11/4/83 160 SAGGAR/A
{,,. ~ ~ ',,
recommended that the leak rate considered in the applicant's SAR also be used in determining qualification dose rates.
Response
The assumption of no containment leakage would be applicable to both PWR's and BWR's.
The staff does not consider it appropriate to' assume the technical specification leakage because, measured leak rates may be much lower than the actual technical specification limit and, therefore to assume technical speci-fication containment leakage would may be non-conservative.
Comment 5:
Appendix D.2.3, BWR Containments, is based on Appendix C.2.1, PWR Dry Contain-ments, and should be revised to discuss differences in containment spray and compartmentalization.
Response
The staff disagrees with this comment.
There is enough information in Appendix D.2.1 so that a designer can model the differences in the spray system parameters for PWR and BWR spray system.
The differences in containment design would be a function of the types of BWR containment and would not lend itself to a simplo discussion.
We believe the best approach is to permit a designer the opportunity to determine the radiation environment using the enveloping guidance provided in this appendix.
No changes were made as a result of this comment.
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Comment 6:
A decontamination factor of 10 for iodine removal in the suppression pool is at least two orders of magnitude lower than is justified (i.e., see NED0-25420 -
"Suppression Pool Scrubbing Factors for Postulated Boiling Water Reactor Accident Conditions").
It is inconsistent for the NRC to allow a scrubbing factor of 104 for PWRs (page 21, item 11) which require water droplets falling through space to collect airborne iodine while only allowing a DF of 10 for Mark III BWRs, which, because of their inherent design, guarantee total contact between iodine and the suppression pool. It is, therefore, recommended that an overall DF for I and Csl of at least 103 be given for the BWR suppression 2
pool.
Comment 7:
One important area that deserves additional comment concerns the decontamination factor for iodine removal by the suppression pool contained in Appendix C, Section 2.3, Item 1 of the propased rev!sion.
Regulatory Guide 1.89 gave credit for a factor of 10 reduction in iodine concentration for a suppression pool and a factor of 104 for containment sprays.
We find this conclusion unjustified in light of TMI results and current knowledge of decontamination by water pools.
General Electric recently completed tests to confirm the fission product scrubbing efficiency of the BWR suppression pool. We consider the results to be a breakthrough in demonstrating the accident mitigation features of the BWR resulting from postulated accident conditions.
The tests support an overall scrubbing decontamination factor (DF) of at least 10,000.
Since the tests were performed for non-condensing conditions typical of a saturated pool, post accident conditions in which condensation occurs would actually be expected to give decontamination factors greater than 10,000.
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Response (Comment 6 and 7)
The assumptions for a pool scrubbing factor of 10 for iodine are based upon information contained in Section 3.2.2 of Appendix VII to NUREG-75/014 (WASH-1400).
Using the decontamination factors for the different iodine species and the 'ractions of iodine species assumed released, the overall airborne iodine reduction factor is approximately a factor of 10.
The staff Mtes that iodine pool scrubbing factors are undergoing staff review as part of the GESSAR review.
Modifications to the staff assumptions may occur after the staff review has been completed.
Comment 8:
Why did the "Airborne Noble Gas Dose" values decrease so much from the February 26, 1981 draft of the Guide?
Response
Draft dated February 26, 1981 was a "working draft." The basis for the numbers reported in Appendix C to this guide (Revision 1) are an extension of work begun in connection with publication of NUREG-0588.
Comment 9:
In Appendix D, the text should refer to Figure D-1 and Tables 0-1 and 0-2 vice Figure B-1 and Tables 8-1 and B-2.
11/4/83 163 SAGGAR/A l
s Comment 10 LThel reference to Figures and Tables "B" should be "D".
Response (Comment 9 and 10):
The staff agrees with the comment the references to the Tables and Figures have been corrected.
Comment 11:
Total dose (R) at 1060 hours0.0123 days <br />0.294 hours <br />0.00175 weeks <br />4.0333e-4 months <br /> should read 1.5E+7 rather than 1.53E+e,
Response
The staff agrees and the entry in Table 0-1 has been corrected.
Comment 12:
Because of the short range of betas in any given component, the application of the infinite medium approximation would be overly conservative.
For a component of minimal thickness, the semi-infinite model would be more accurate.
Therefore, it is recommended that the semi-infinite model is used to develop beta airborne doses, and if special cases warrant the use of an infinite model, that they be explicitly identified.
Response
The staff has provided additional clarification on the use of infinite, semi-infinite and finite cloud models for estimating beta doses for equipment 11/4/83 164 5AGGAR/A
e qualification in_Section 3 of Appendix 0 to the regulatory guide.
The clari-fication should resolve this comment.
Comment 13:
Appendix C, Section 3 states that the final results of gamma dose calculations were "multiplied by a correction factor of 1.3 as suggested in Reference 5" in accounting for contributions for decay chain isotopes.
Reference 5 (M. J.
Kolar and N. C. Olson, "Calculation of Accident Doses to Equipment Inside Containment of Power Reactors", Trans Am Nuc Soc, Vol. 22, 1975) in fact states "ignoring decay chains results in total integrated doses, which are 10% lower than with decay chains." Therefore, the appropriate correction factor should be 1.1.
Response
The staff diagrees with this coniment.
The basis for the factor of 1.3 is the following quotation from the article:
"The 720-hour total integrated dose for Case 2 is 31 percent higher than for Case 1."
In this quote Case 1 is an instantaneous release of fission products with no decay chains and Case 2 is an instantaneous release with the decay chains included.
Comment 14:
Is the TACT code publicly available?
Response
The TACT code is being doucmented and a user's manual is being prepared as part of a contractual effort with the Oak Ridge National Laboratories.
Following completion of this effort, the TACT program will be available through the Radiation Shielding Information Center at the Oak Ridge National Laboratories.
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h f~
Comment 15:
The accuracy of the assumptions seem to be beyond that which is necessary
'(e.g., 3 place accuracy on numbers).
Response
The values used for the assumptions are only examples used in the staff analysis.
k The numbers are provided so that the staff methodology may be duplicated by those wishing to do so.
It does not require any plant specific calculations use three place accuracy for significant parameters.
Comment 16:
A position should be established on the maximum time after an accident for which radiation doses should be integrated.
A maximum time period of 1 year should be a sufficient upper bound value and would allow time for either replacement or subsitution for any specific piece of equipment.
Comment 17:
This appendix requires equipment to be qualified to the equivalent of a one year integrated dose rate.
This would require extensive testing.
Analysis with supportive test data is a viable alternative.
Response (Comment 16 and 17):
Appendix D does not require qualification equivalent to a one year integrated dose. The actual qualification value should be based upon the equivalent life-time, which considers both the normal radiation environment and the time the equipment is needed to function following an accident.
The Tables and Figures in this Appendix are for information only.
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1 s
Comment 18:
What is implied in this sentence?
(Page 19, para 1, last sentence).
Comment 19:
The last sentence in Section 1 of Appendix 0 makes much of the language in this section obsolete, as it leaves the question of source terms open to NRC modification without industry review and comment. We concur that revision to existing source terms is needed.
We suggest that the completion of the current ORNL effort on best estimate source terms used in the enviromaental qualification area be expedited. If this is not done, one of two alternatives face industry.
Either we run the risk of having to spend considerable efforts redoing qualification due to the generation of source terms which potentially could indicate nonconservatisms in those terms currently in use, or we will be forced to spend extra funds to qualify to terms which are unduly conserva-tive. This issue needs to be resolved before this Regulatory Guide is revised.
Comment 20:
i In Appendix 0, the last sentence in section 1 (page 19) should be deleted.
Response (Comment 18 thru 20):
The staff agrees that the sentence in question is confusing.
This section has been rewritten to identify current staff efforts in the source term area and to discuss how this information will be factored into the licensing process.
i 11/4/83 167 5AGGAR/A I
T y
Appendix E Comment 1:
This Section requires identification of all electric equipment regardless of location.
Equipment located in areas deemed to "Mild Environment" should be exempted from this requirement.
Comment 2:
Incorporation of this Appendix (which was originally an NRC review question to -
specific OL applicants) as a documentation requirement (per Regulatory Position C.10) is of doubtful salue.
If it is to be included, clarification is required that this information is required for equipment exposed to a "harsh" environment only for items 5, 6, 7 and 8.
j Comment 3:
Sections 5 through 8 should only be applied to Category "a" and "b" equipment (as defined by Section 3).
Category "c" and "d" equipment are either non-safety related or located in mild environments.
Hence, the only appropriate documen-tation requirements for Category "c" and "d" equipment should be governed by the guidelines of Section 4.d of this proposed Appendix.
Comment 4:
It appears the information covered by this appendix be provided for all electric equipment covered by the regulatory guide.
This should not be applied to the items which fall into item 3 category c and d since these items are in the "mild environment' and should not require item 4, item 5, item 6, or item 7.
At most, documentation of devices in the ' mild' areas should include (1) a list 11/4/83 168 SAGGAR/A
7 of devices by contract (purchase order) listing only manufacturers and model numbers, (2) definition of plant normal and abnormal extremes for each type (by manufacturer and model number) of device, (3) reference to a certificate of conformance which documents that each type device meets or exceeds the required environmental conditions for continuous service or reference to an analysis which supports a conclusion that the device will operate under the extremes.
Response (Comment I thru 4):
Appendix E specifies requirements for qualification documentation for electric equipment important to safety covered by RG 1.89, except equipment located in a mild environment.
Comment 5:
Equipment located in areas that will not experience the environmental conditions resulting from a design basis accident (nild environment) should be exempted from this requirement (E.3.c).
Comment 6:
This classification (E.3.c) should be re-defined.
Comment 7:
Equipment described by this statement (E.3.c) is not Class 1E, lies outside the scope of this guide, and therefore does not have to be identified per Appendix E.1. (As an aside, since this equipment is not safety-related, it does not even have to be qualified for its normal service environment as
' stated.)
11/4/83 169 5AGGAR/A
e.
66 Comment 8:
It is suggested that further clarification and examples be given for the categories shown, i.e., a. is equipment in "harsh" environments; b. is "associated circuits" per Regulatory Guide 1.75 and IEEE Std. 384; 4c appears to be catego-rized as "mild" environment equipment but the description does not fit the definition given in C.S.a; d. is clearly "mild" environment equipment.
Comment 9:
It should be pointed out that the equipment described here (E.3.d) is the same as that in a mild environment covered by Section C.5.a.
Comment 10 This category (E.3.d) defines equipment located in a "mild environment". It should be recognized that Appendix 0, Sections 5, 6, 7 and 8 do not address the allowed exclusions from test data, etc., for Category 3.d as permitted by Section C.S.a of the Regulatory Position.
Comment 11:
E The words "to failure," should be deleted from each of these items (E.3.a and E.3.b).
Response (Comment 5 thru 11):
Paragraph E.3.d has been deleted.
Equipment located in a mild environment is not covered by Appendix E.
However, Nonsafety-related equipment, as specified in 10 CFR Part 50.49(b)(2) is covered by Appendix E.
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(.
l Comment 12:
'The "environmental envelope" that is required by these statements (E.4.b and E.4.c) would be overly conservative if it included environments that are mutually exclusive.
For example, a device would be subject to either a LOCA environment or an MSLB environment, not both simultaneously.
I
Response
The environments which are not mutually exclusive are covered by these statements.
Equipment should be qualified to environmental conditions it is expected to be exposed to.
l Comment 13:
1 l
Final Rule Section 50.49 of 10 CFR Part 50, paragraph d(2), requires the equipment l
list to contain "the range of voltage, frequency, load, and other electrical l
characteristics for which the performance...can be ensured." Appendix E does not require this and should be modified accordingly.
Response
This information should be maintained in "qualification file."
l Comment 14:
The requirement to, "Provide the qualification...." requires a determination of to whom, when, and where information is provided.
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b
' as
Response
The information requested must be provided to NRC prior to issuance of an-
-operating license.
Comment 15:
In various NRC/ Industry meetings the NRC has rather consistently indicated that environmental qualification submittals should be on Component Evaluation Sheets and Master Lists in general accord with the format first included in IEB79-01B.
The NRC should indicate whether these requirements are no longer valid to p 'clude a repeat of the unnecessary rework of EQ data prepared f'or NUREG Catvg.'y II plants which was not in the IEB 79-018 format.
Response
Resubmittals are not required.
Use of any of the provisions of this Guide by operating plants or NT0Ls is optional.
1 I
6/16/83 172 SAGGAR/A
'a s
Value/ Impact Statement Comment 1:
The value impact statement supporting this proposed revision is not based on the actual industry costs asscciated with meeting these new requirements.
This is the case, since this impact assessment seems to use NUREG-0588 and 00R guidelines as the current basis and not Revision 0 of Regulatory Guide 1.89.
The impact on industry is significant both from the standpoint of dollars expended as well as expansion of manpower requirements.
These need to be adequately represented.
The Value/ Impact statement is based on going from the existing basis of NUREG-0588 and 00R guidelines, which are commonly subject to misinterpretation, to R.G.
1.89, Revision 1, which attempts to bring some order to this subject.
Since NUREG-0588 and 00R guidelines were applied without benefit of public comment or Value/ Impact review, the current Value/ Impact statement should address the benefit and impact of going from R.G. 1.89, Revision 0, as originally implemented to R.G. 1.89, Revision 1, as proposed.
Industry is currently spending many millions of dollars to upgrade their qualification to these requirements.
The Value/ Impact statement must reflect this cost in both time and money.
Comment 2 The impact portion of this statement is inaccurate.
The cost and safety impact of applying the guidance provided by this issue of Regulatory Guide 1.89 versus the November, 1974 issue is quite large.
The statement ignores the impact of applying original direction, much of which resulted in an adverse impact on cost and safety.
Additionally, the statement implies that this issue of the regulatory guide is nothing more than implementation of industry endorsed positions, which is not true.
A full and accurate impact statement for-this m $ ject should be made by NRC.
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B Response (Comment I and 2):
Value/ Impact statements are based on the changes in values and impacts with respect to requirements in effect at the time a rule or guide is made effective.
The applicants for and holders of operating licenses are not required to requalify electric equipment important to safety in accordance with the provisions of this Guide; i.e., use of this guide is optional for them, except for replacement equipment.
Consequently, this Regulatory Guide dces not impose any new costs or obligations on such utilities.
Comment 3:
Any increase to the scope of equipment requirinc qualification to this guide will have major financial impact on the licensee.
Qualification is unlikely to yield any offsetting benefit to the licensee during normal operation.
The upgrade can only be measured in terms of reducing the risk, both commerical and health, following an accident.
The whole subj*ct of Systems Interaction being investigated under Task Action A-17 is struggling with the complex problem of defining what upgrades, if any, are necessary of currently identified control grade equipment to reduce the potential for system inter-action to an acceptable level.
For the NRC to claim that the potential impact of this issue is minimal, is simplistic.
7
Response
The scope of the electric equipment requiring qualification has no+, changed vis-a-vis current regulatory positions (e.g., 00R Guidelines, NV.r.EG 0588, Reg Guide 1.75, Reg Guide 1.97).
Comment 4:
The impact of introducing the new source term is, probably, to require repeat qualification testing of existing equipment at significant financial cost to t
6/16/83 174 5AGGAR/A
...... _.. ~ ~. - -
27-a u
the licensee. The implication that there is no impact, just because the requirement fills a licensing void, is not logical.
We strongly recommend that the NRC complete a true cost / benefit assessment of this proposed guide since the changes introduced, compared to previous regulatory documents on this issue that were submitted to public review, are major.
Comment 5:
The DRAFT VALUE/ IMPACT STATEMENT does not address the change made to cesium in the sourcc tarm which will require a major amount of reanalysis by every plant but will not add to plant safety.
Response Comment 4 and 5):
The staff has revised the source terms to incorporate the previous guidance contained in 00R Guidelines and NURIG 0588 and to remove the proposed addi-tional cesium source term.
Thus, no new impact.
Comment 6:
It is stated, "With the possible exception of Regulatory Position C.1, the impact should be minimal since the scope has not been changed from current praciice. This statement is far from being accurate.
The cost of previous NRC doctments NUREG-0588 and the 00R Guidelines has already taken a toll on the 4
nuclear industry. Each attempt to make and codify more definitive criteria for environmental qualification such as this guide and the associated rule increases the impact.
While it is hard to determine the overall costs, we estimate that a small army of from 3,000 to 5,000 persons are working on this issue in one way or another in the United Sates today.
This effort and its attendant cost (up to two million dollars per day) is out-of proportion to its potential for risk reduction.
11/4/83 175 SAGGAR/A
s.
O It appears the industry resources being 40 voted to equipment qualification may yield higher safety payoff if applied to other pressing nuclear safety issues or, indeed, other areas that can lead to improved equipment performance such as environmentally hardened designs or resolutions of problems in manufacturing, installation, startup, operation and overall station management.
It may very well be that expenditure of resources to improve practices, procedures and training in some of the latter areas would be more cost-effective than the prescriptive, rigorous approach being applied to the isolated issue of equipment qualification.
Another approach which might be more cost effective for some utilities is to extend a probabilistic risk assessment (PRA) to estimate the risk associated with certain equipment failure and then to concentrate efforts on those items which significantly reduce overall risk.
Response
See response to Comment 1 and 2 lpage 174).
Comment 7:
Regulatory Guide Position C1 requires qualification of associated circuits as defined in Regulatory Guide 1.75.
This will require that all non-safety-related components of these circuits are designed, qualified and documented to survive accident envronments. If any, this may provide only a small decrease in the vulnerability of safety-related equipment to "system interaction" types of failures.
The physical separation criteria specified in Regulatory Guide 1.75 and IEEE-384 are principally based on a concern for protection from disabling fires.
Circuits, cables and equipment classified as physically-associated cannot be construed as posing threats to Class 1E circuits during LOCAs and HELB-type accidents. Electrically-associated circuits are presently designed to minimize the spread to safety-related circuits of the type of circuit faults which may 11/4/83 176 5AGGAR/A
Ig g-occur as a result of LOCA-type accidents.
Qualification of all components of these non-safety related circuits is not part of the present-day design process and qualification of equipment in these circuits would not yield any identi-fiable increase in safety.
Regulatory Guide 1.75 does not apply to those operating plants which have received Safety Evaluation Reports prior to February 1974.
Thir, position implies that Regulatory Guide 1.75 is now being backfitted to these plants.
The process of identifying all such associated circuits in compliance with this Regulatory Guide is a task of considerable complexity and magnitude and will equire a huge commitment of utility resources.
Since most operating plants were not designed in accordance with this Regulatory Guide, a large number of circuits previously-defined as non-safety circuits would be required to be redefined as associated circuits per the guidance of Regulatory Guide 1.75 and qualified per the; guidance of this Regulatory Guide. The result would be the identification of a large amount of non-safety-related equipment, (such as annunciators, motor and switchgear heat?rs, computers, etc.) and non-safety-related circuits and cables.s associated and, therefore, requiring qualifica-tion. Once the extensive process of identifying such equipment and circuits was completed, the additional task of performing h:Oure Modes and Effects Analysis, qualifying and possibly replacing this equipment would begin.
The scope of this effort would be enormous. It is pctentially much more extensive than the previously-conducted Class 1E qualification reviews.
This equipment was appropriately designed, procured and installed as non-safety-related and consequently was not environmentally qualfied.
Thus, there is a high probability that plant modifications will be required to requalify and replace this equipment. We submit that the process of modifying this non-safety equipment introduces sufficient risk which will far outweigh the undefinable, negligible incremental decrease in risk which may result by "upgrading" this non-safety-related equipment.
11/4/83 177 5AGGAR/A
7 T
Response
Regulatory Guide 1.75 does' not apply to those nuclear power plants which have received SERs prior to February 1974.
By this Regulatory Guide, it is not intended to apply R.G. 1.75 to these plants.
Comment 8:
Regulatory Position C2 requires seismic qualification in 6ccordance with IEEE Std. 344 and Regulatory Guide. l.100.
In addition it requires the use of a single prototype throughout all such seismic and environmental testing.
This requirement, the use of a single prototype, is waived for operating plants per
- Section D.2 and is consistent with these plant's past qualification practices.
The main body of probabilistic risk assessment work done to date for nuclear power plants has consistently provided quantitative evidence that the sequence of earthquake causing LOCAs is a very small contributors to overall risk.
The principal reason is that in the ASHE codes and the industry's licensing bssis required the design of piping systems and components for the simultaneous occurence of SSE and LOCA, thereby providing significant design margin.
This piping system design process of combining SSE and LOCA should not arbitrarily become the rationale for their concurrent application for electrical equipment qualification.
Earthquakes do create risks for nuclear power plants but those event sequences that are significant risk contributors which result from design basis earthquakes do not contain LOCAs. The high risk sequences for seismic events contain failures in structures, equipment and systems OUTSIDE of the Reactor Coolant Pressure Boundary.
We believe that this position's reference to Regulatory Guide 1.100 does not require compliance fo plants not previously committed to the Regulatory Guide (Construction Permit applicants prior to November 15, 1976).
Therefore, no impact results from this interpretation for these operating plants.
If, conversely, the Staff is considering imposin0 IEEE-344 and the Regulatory Guide to plants previously committed to a differing licensing basis, then the resulting cost to perform such additional seismic reviews and qualifications l
11/4/83 178 SAGGAR/A I
T.,
for all operating plants is essentially equivalent to the cost of performing new seismic qualifications for all such equipment.
The impact of directing industry resources to perform such requalification reviews to the latest of the evolving seismic qualification methodologies for all operating plants is unwarranted.
Sufficient conservations have existed in all the seismic quali-fication methodologies historically used by the industry to provide adequete assurance of equipment performance.
For NT0Ls and CP plants this position requires a single prototype to be tested in the sequence indicated in Section 6 to IEEE Std. 323-1974.
The requirement to test one component for the concurrence of a LOCA and a seismic event (which is implied) is not a valid requirement and is a misinterpretation of this IEEE standard.
The impact of requiring such a combination of two Design Basis Events unnecessarily overstresses equipment during qualification testing and artificially excludes from use as safety-related equipment devices which can adequately perform these safety functions.
Thus, a secondary, but very significant impact is a narrowing of the industry's manufacture and equipment base which can be selected for use in nuclear power plants.
This narrowing will exclude state-of-the-art hardwarc which may otherwise have been found acceptable or preferable.
t
Response
Testing of a single prototype in the sequence indicated in IEEE 323-1974 is i
preferred. However, the staff recognizes that electric equipment at operating nuclear power plants and NTOLs was generally qualified for environmental and seismic stress separately i.e. by using separate prototypes for environmental and seismic qualification tests.
This Guide does not require retesting for environmental stresses simply becasue a single prototype was not used during the original qualification.
11/4/83 179 SAGGAR/A
Comment 9 Regulatory Position C3 limits the use of analysis and operating experience as qualification tools and, therefore, lessens the burden placed on the Staff to perform detailed reviews of qualification determinations made by such methodo-logies.
Without these detailed reviews, the Staff apparently does not believe that they can ascribe the same level of confidence to such techniques as is achieved by testing. When properly performed, analysis and operating experience can yield a level of assurance equal to or greater than that achieved by testing.
Position C3 is a significant deviation from the previous Regulatory Guide requirements.
The exclusion of these valid methodologies dramatically increases licensee's costs by forcing the use of one selected methodology (testing).
Excluding other types of qualification previously permitted does not provide the necessary flexibility to assure cost-effect solutions.
Requiring the replacement of existing equipment previously qualified by analysis or operating experience with equipment, subcomponents, or parts which must be qualified or requalified by testing imposes a significant cost burden and generates unnecessary plant modifications.
Response
NRC prefers testing.
However, the equipment may be qualified by any one of the four methods described in 10 CFR Part 50.49(f).
Replacement equipment must be upgraded unless there are sound reasons to the contrary, such as those described in Section C.9 of this guide.
Comment 10:
Regulatory Position C.4.a provides detailed guidance on the acceptable methods of calculating accident environmental conditions by requiring the use of the most recently developed industry codes.
The use of these codes for all plants 11/4/83 180 SAGGAR/A
Y._
y will require recalculations for some existing facilities, but would provide a usiform treatment of accident parameters ano' may facilitate Staff audits and reviews.
The small difference in the calculated values which might result from the use of these newer code versions is not significant when compared with the inherent conservatism contained in all the models historically used.
Therefore, the value of requiring such recalculations is negligible.
Position C.4.a requires the use of the versions of the industry codes identified in Appendix B.
These versions have not previously been used for most operating plants.
Recalculation of LOCA and MSLB pressures and temperatures using the latest versions of these licensing computer codes requires a significant committment of both industry and Staff resources.
Further, any detailed reviews of the analyses previously performed for these plants to determine their similarity to existing methodologies are also costly and a wasteful use of industry and Staff resources.
The use of these latest code versions for older plants was not previously considered as part of the Interim Requirments.
The Staff had previously permitted the use of existing FSAR licensing calculations.
This Regulatory Guide implies that this is no longer acceptable.
The output of these activities will not be a substantive change in the existing levels of qualification or plant safety.
The resulting activities will impose unnecessary and unwarranted resource burdens on both the Staff and licensees.
Response
Applicants for and holders of operating licenses, who are qualifying equipment in accordance with 00R Guidelines or NUREG 0588, are not requ' red to meet the provisions of Regulatory Guide 1.89, except for replacement equipment.
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~
Comment 11:
Regulatory Position C.4.b requires consideration of NUREG-0800, "Standard r
Review Plan" (SRP) when developing chemical spray environmental parameters.
This SRP has not been a licensing basis for existing operating plants.sithough similar guidance was historically used for these plants.
Specific conformance with the exisitng SRP's requirements for operating plants will provide a negligible increase in the protection of the public health and safety, i.e.,
the position has little or no value given the level of protection achieved via conformance with the existing plant licensing basis requirements.
F p
Comment 12:
Regulatory Position C 4.d(1) requires consideration of high-energy pipe breaks as defined in the SRP.
This SRP has not been a licensing basis for most existing operating plants, although the general guidance previously used was essentially equivalent.
Since the degree of protection of the public health and safety provided by these previous activities is equivalent to that which would be achieved by specific conformance with the SRP, little value will result from imposing these specific requirements on operating plants.
Response (Comment 11 and 12):
All references to SRP (NUREG-0800) have been deleted from the Regulatory positions.
r 1
Comment 13:
Regulatory Position C.4.d(3) requires safety-related equipment "not served by environmental support systems within the scope of this guide" to be qualified to the abnormal environments which may exist during plant states when such equipment does not perform a safety function.
The need to dpmonstrate equipment i
Y 11/4/83 182 SAGGAR/A I
operability during such plant statss would cause an insignificant increase in plant safety since no safety function is provided by this equipment during these states.
b
Response
Regulatory position C.4.d(3) has been deleted.
Comment 14:
Regulatory Position C.S.a requires the definition of environmental conditions in equipment design and purchase specification for all safety related electrical equipment located in mild environments and the generation of vendor documentation (a certificate of compliance) to attest to the capability of such equipment to perform.
This requirement provides a consistent documentation basis which can be used by the Staff to audit all plants.
However, the development of such documentation for equipment whch has successfully operated in existing plants within mild environments provides no incremental increase in plant safety.
\\
Response
The scope of this Guide does not incude equipment located in a mild environment.
Comment 15:
Regulatory Position C.S.b imposes new criteria by requiring assurance of the I
integrity of watertight enclosures solely by testing to the exclusion of partial type testing, analysis and/or operating experience.
This limitation on the use of other qualification methodologies has the positive effect of minimizing staff review of other qualification methods.
However, the exclusion of analysis and operating experience provides no overall increase in plant I
11/4/83 183 5AGGAR/A
I p.
safety or_in the protection of the public health and safety given previous
-conformance to the Interin Requirments.
Response
l The requirement to qualify solely Ly testing has been deleted.
Comment 16:
The one-hour requirement of Regulatory Position C.6.b requires additional qualification margin and assumes some resulting incremental increase in engi-neering confidence in equipment capability.
The requirement is arbitrary and not causally linked to existing design basis accident scenarios.
The conser-vatism built into existing qualification practice is adequate to assure opera-bility in the absence of an additional one-hour margin requirement.
Therefore, the position yields no quantifiable positive incremental _value.
Response
\\
The revised regulatory position allows a true margin of less than one hour, if justified.
Comment 17:
Regulatory Position C.7.a contains the implied requirement that synergistic (second order) effects bE Considered during qualification for all equipment in all plants.
A value-impact determination is difficult to quantify since the Staff remains unclear with respect to what constitutes "identified", by whom it must be identified, or how one "accounts" for such effects in the qualification programs.
Any resource licensecs may divert to investigate such synergistic effects would be more appropriately focused into other areas of 11/4/83 184 5AGGAR/A
g~.
f,.
t
. qualification or into other safety issues.
Therefore, this requirement has little quantifiable value.
Response
Synergistic effects known at this time to the staff are included in Regulatory Position C.7.a.
/
I i
s 11/4/83 185 5AGGAR/A I....
.