ML20198P163
| ML20198P163 | |
| Person / Time | |
|---|---|
| Site: | Westinghouse |
| Issue date: | 12/29/1998 |
| From: | Goodwin W WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | Gaskin C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| CON-NRC-98-061, CON-NRC-98-61 TAC-L31067, NUDOCS 9901060342 | |
| Download: ML20198P163 (10) | |
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Westinc' case Electric Company Commercial Nuclear C
bi, SC 29250 a division of CBS Corporation
. Fuel Division (803) 776-2610 December 29,1998 NRC-98-061 U. S. Nuclear Regulatory Conunission
' Attn.: -Mr. Charles E. Gaskin, Project Manager Licensing Section 1, Licensing Branch Division of FCSS, NMSS 11545 Ro'ckville Pike Mail Stop T8D14
- Rockville, MD 20852-2738
.SUBIECT:
WESTINGHOUSE RESPONSE TO RAI REGARDING LICENSE REVISION
-10.0 - CRITICALITY SAFETY (TAC NO. L31067)
REF: WESTINGHOUSE LICENSE SNM-1107/ DOCKET 70-1151
Dear Mr. Gaskin:
Enclosed herewith is the Westinghouse response to your subject RAI dated October 29,1998.
Should you have any questions following your review of our response, please contact me at (803) 776-2610-Ext 3282, and we will be happy to discuss this matter with you.
Sincerely, WESTINGHOUSE ELECTRIC COMPANY D
. Wilbur L. Goodwin, Manager L.-
Regulatory Affairs 1
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. cc: ' O.s. Nuclear Regulatory Commission Document Control Desk Washington, DC 205$5
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PDR ADOCK 07001151 C
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1 Westinghouse Response to:
Request for Additional Information Application Dated March 31,1908 Westinghouse Electric Corporation Docket 70-1151 Please provide the following information:
1.
In the license application, you reference ANSI /ANS-8.1. You should include in the license application the revision number and date of any material or document that CFFF commits to (e.g., Subsection 6.1.3 (c), (9), (I),
- (k.2-three instances),6.2.3 (c) and 6.5.1). Otherwise, if the standard or document changes, you would not be in compliance with your license until you changed yow systems to correspond to the changes in the standard or document. In addition, when describing specific records requirements in the licenso application, as in Subsection 6.1.3 (b), refer to.the section in the license application that describes the general-records requirements.
Westinghot;se - Westinghouse will add dates to all ANS standard references.
Westinghouse will also add a reference to Subsection 3.8 under Subsection 6.1.3(b).
2.
Subsection 6.1.1, clarify that the defin tion of Double Contingency used by CFFF is different from the National j
i Standard ANSI /ANS-8.1 (1983). JusWy changing the Standard words from " As such, process designs.." to "Where practicable, all process designs..." and "... margin of safety..." to "... factors of safety.. " Also, in the license application, define the term "significant process" as in "Significant process within the system."
Westinghouse - The Westinghouse definition for Double Contingency Protection
'{DCP), which begins, "Where practicable,..." is stronger than the ANSI Standard definition, which begins, " Process designs should, in general,..." The word "should" denotes a recommendation, not a requirement. On the other hand, the Westinghouse definition indicates that all pr%ess designs will offer DCP protection except in cases where it is.not practicable. Practicable is defined as "where capable of being done,"
which means if at all possible, Westinghouse. meets DCP for all current systems (subject to confirmation in ongoing CSEs and ISAs), and will apply DCP protection to new designs. It is not conceivable of a design not being able to have DCP protection applied to it. But, however remote the likelihood, Westinghouse reserves the right to e
proceed with adequate nuclear criticality safety protection should this situation arise.
Westinghouse agrees to change the words " factors of safety" to " margins of safety".
The term."significant process" is merely intended to distinguish between components for which DCP protection is unnecessary from those for which it is.
L 3.
in Subsection 6.1.1, correct the reference to the piogram for routine testing and maintenance from Subsections 3.2.2 and 3.2.3 to Subsections 3.2.1 and 3.2.2.
L Westinghouse - Westinghouse agrees to change the references.
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' 4.
In Subsection 6.i.2 state that assurance of passive engineered controls is maintained through specific periodic inspectons or verification rrcosurement(s) as appropriate. State that assurance of actve engineered controls j
(AECs)is maintained through specific periodic functional testing as appropriate, and that AECs are fail-safe in that the failure of the control results in a safe conditon. State that assurance of administrative controls (ADMCs) i j.
. is maintained through training, experience, and audit You should maintain onsite for NRC review a complete list e
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y of the types of controls and where the controls are at CFFF that are used as " Passive Engineered," " Active Engineered," and " Administrative" controls.
Westinghouse - In Section 6.1.2, we agree to add statement similar to, " Assurance of passive and active engineered controls is maintained through specific periodic
, inspections or functional verifications as appropriate. The ISA/CSE will determine whether or not inspections or verifications are required. The reliability of administrative controls is ensured through training, experience, and audit."
With regard to the comment abot,t ac'ive engineered controls being " fail-safe,"
although this is definitely true as much as practicable for all new process designs, there are some older vintage active engineered controls which are not fail safe. For these, the control's reliability is assured through compensatory means. Furthermore, only reliable controls are used to establish DCP. Therefore, fail-safe conditions are not always required since the controls are reliable and not expected to fail.
5.
Subsection 6.1.3 (a), explain CFFF's methodology regarding
- Geometry" control. " Favorable geometry" control,
" San geometry control," and " Geometry control systems."
Westinghouse - The CFFF methodology regarding " Geometry" control, " Favorable geometry" control, and " Safe geometry" control, will be included in the NCS Handbook.
6.
h Subsection 6.1.3 (a), incorporate into Subsections 6.1.3 (a.1) and (a.2) the same requirements for analyzing, evaluating, and periodic inspection that Subsection 6.1.3 (a.3) contains.
' Westinghouse - A closer reading of our Section 6.1.3 (a.3), Geometry control systems, indicates that this paragraph really is a continuation of paragraph 6.1.3 (a), and will be moved to that paragraph.
L 7.
Subsection 6.1.3 (a.2), justify why and how,
- Favorable geometry may also be achieved through othei means, including level control." Favorable (or safe) geometry is normally a passive control. Trying to achieve favorable geometry through the use of level control is an active control that would have a different set of requirements associated with its functional testing and other uses. Thus, with the proposed Subsection, equipment like the moisture drop-out pots can still be characterized as favorable geometry, and would be so for liquids (as long as i
the level controls worked), but would not necessarily be favorable for solids buildup. Remove from Subsection 6.1.3 (a.2) the use of level controls as " favorable Geometry if its use cannot be justified."
Westinghouse - Westinghouse agrees that a component whose geometry is controlled i
by level should not be refered to as " favorable geometry". Westinghouse agrees to re-i write Subsection 6.1.3 to include s paragraph' regarding control of a non-favorable geometry using level control. This will still be considered geometry control but will L
not be refered to as favorable geometry.
7 8.
Subsection 6.1.3 (a.3) mentions provisior's for periodic inspection, but does not state from where thesc 4
j provisions will come, nor does it mention frequency. Better wording can be found in Subsection 6.1.3 (9) which i
says, "The presence of the absorber...will be verified on a frequency determined in the CSA, CSE, or ISA."
Incorporate into Subsection 6.1.3 (a.3) the requirement that the CSA, CSE, or ISA shall identify the frequency of the periodic testing for all the kinds of geometry control systems.
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1 Westinghouse - Frequency of control testing is a function of system reliability. The frequency of testing is based on the expert knowledge of the engineer who maintains that control such that the control may be considered reliable. Frequency of control verification and testing is maintained by the Maintenance function at the CFFF.
Therefore, the frequency of control testing will not be stated in the Criticality Safety Evaluation or Analysis (CSE or CSA).
1 i
Commitment is made by Westinghouse to identifiy the frequency of periodic inspection or testing of neutron absorbers for criticality safety because ANS-8.21-1995, Section 5.3.1.1 statea "The required frequency of inspection and the extent of in-service i
. verification shall be determined." This determination is best made by the nuclear
_ criticality safety engineer, with the assistance of other disciplines like Quality Assurance, who understands the safety margin of the system and importance of the neutron absorber as a criticality safety control.
The frequency of inspection for neutron absorbers used for criticality safety control will continue to be determined by the criticality safety engineer in the CSA.
9.
In Subsection 6.1.3 (b). state that the establishment of mass limits includes the given considerations of all fissile material bearing units in the individual room or groups of rooms and include the last sentence from the current license provision 6.2.4 (b):
- when ocly administrative controls are used for mass controlled systems, double batching is assumed to be the worst credible upset condition." Also, clarify what is meant by "...the definition of subsequent controls."
Westinghouse - Section 6.1.3 (b) paragraph 2, second sentence, will be revised to read,
- " Establishment of mass limits for a room or group of rooms will invclve consideration of potential..."'
The sentence, 'When only administo,tive controls are used for mass controlled systems, double batching is assumed to be the worst credible upset condition." will be added to the end of Subsection 6.2.4 (b).
The sentence regarding "...the definition of subsequent controls." will be reworded to the following:
"The evaluation will consider normal operations and expected process upsets for determination of the actual' mass limit for the system and for the definition of subsequent controls necessary to prevent reaching a criticality safety limit."
'10. In Subsections 6.1.3 (c.1) and 6.1.3 (e.1). define ' independent results of sampling used by CFFF" and explain why this description of independent sampling and independent controls / measurements are included in these Subsections, but are not included in an overall discussion of independence used for any of the controls.
Westinghouse - The wording in question is meant to apply when moderation or
. concentration is the only parameter used for criticality control. In that circumstance, independent sampling, etc., is required. It may also be used in other applications. The license application will be reworded to clarify this.
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- 11. In Subsection 6.1.3 (c.2), state that moderator controls will be used to prevent uncontrolled moderator from entering the system after each loading (e.g., initial and subsequent) has occurred and state a frequency of testing for leakage of outermost barriers after each installation (e.g., not just initial installation). Also, define what is meant by "promptly self-disclosing."
Westinghouse - Section 6.1,3 (c.2) will be revised to read, " Controls will be established to remove uncontrolled moderator prior to returning a system to production i
and to prevent uncontrolled moderator from entering the system after each loading has occurred."
The frequency of testing of outermost barriers is specified by Maintenance operations, "Promptly self-disclosing" means immediately obvious to operators in the area
- 12. In Subsection 6.1.3 (d), state that when Enrichment control is not utilized, the maximum licensed enrichment is assumed rather than the maximum credible enrichment.
. Westinghouse - Westinghouse regards the phrases " maximum credible enrichment" and
" maximum licensed enrichment," as equivalent.
- 13. Subsection 6.1.3 (e.2), the concentration of what will be prevented by the establishment of controls? State that i
. this prevention will be done after eacn loading (e.g., not iust the inRial loading). State that each system will have, in place and operating, controls to detect and/or mitigate the effects of intemal concentration within the system.
Westinghoose - Paragraph 6.1.3 (e.2) implies by " initial" loading, the first loading in j
each cycle. Westinghouse will reword the sentence to, " Controls will be established to prevent concentration of SNM within the system to unaccepiable levels." The term "in place" means that the controls are present and operating.
- 14. Revise Subsection 6.1.3 (f) to include the industry standard terminology for the use of Reflection in an analysis of the criticality safety of a system (e.g., use of ANSI standards, the use of the term Close-fitting,, and definition of the term "near"). Also, define what is meant by "crediblo process environment" and clarify that the system analysis will be used in determining whether partial reflection can be used in Le system.
Westinghouse - No specific discussion on reflection was found in the ANSI standards, A discussion of reflection will be written into the NCS handbook which defines the necessary terms.
1 Concerning the phrase, " Credible process environment," the sentence containing it,
'"For all system evaluations, the neutron reflection properties of the credible process environment will be analyzed," means that the' surrounding environment of a' system will be used to determine the appropriate reflection properties, i
- 15. Revise Subsection 6.1.3 (g) to include in the first bullet a lower limit for the pH in addition to the upper limit.
Although this bullet is an exception for neutron absorters in basic solutions, the term " basic solutions
- can have
- more than one meaning. Thus, to clarify that the exceptions are for non-acidic solutions, a limit for the pH of no
' less than 7should also be established.
Westinghouse - The sentence will be revised to read " System PH maintained greater than or equal to 7 but less than or equal to 11.
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- 16. In Subsection 6.1.3 (1), state that the effects of heterogeneity will not only be considered. but assessed and
. documented with the appropriate CSA, CSE, or ISA. Also, justify the definitions of homogeneity and heterogeneity used that are based on particle size.
Westinghouse - The first sentence will be revised to indicate that the effects of heterogeneity will be assessed and documented in the appropriate CSA, CSE, or ISA.
The justificaion for the definitions will be incorporated in the NCS Handbook.
- 17. In Subsection 6.1.3 (J.2), state that the basis for Process Characteristics control will be documented in the appropriate C SA, CSE, or ISA.
Westinghouse - It is believed that paragraph 6.1.3 (j.1) and (j.2) together communicate that the appropriate CSA, CSE, or ISA will contain the basis for any process characteristics controls which are used.
- 18. In Subsection 6.1.3 (k.3), reconcile the keff limit shown here with the keff limits in 6.2.3 (a). Modify the license application so that the credible process upset keff imit will be less than 1.00. One attemative is to have the keff l
limit of 0.05 be applicable in all conditions. Also, reference the other applicable section(s) in the license application when discussing validating Monte Carlo computer codes.
Westinghouse - The final sentence of Subsection 6.1.3(k.3) will be revised to read "When array interaction is evaluated in this manner, the maximum allowed Keff will conform to the keff limits prescribed in Subsection 6.2.3."
- 19. In Subsection 6.1.4, state who will perform the comprehensive enalysis, how will the analysis be performed, what analysis result allows the use of a container, and who reviews and signs off on the use of the container.
Also, include in this Subsection the above info.mation conceming Non-Favorable Geometry (NFG) containers.
Wes'tinghouse - The last two sentences of the beginning paragraph will be revised to read "....a comprehensive analysis will be performed by the nuclear criticality safety function in the form of a CSA.
In addition, the following requirements will be included:"
Because this section is titled Moveable Nonfavorable Geometry Containers, information will not be included concerning permanent NFG containers.
- 20. Section 6.2, justify why only the complexity of the system is used in determining whether to perform a CSA, CSE or ISA on a system. Why should not other factors, such as risk and consequence of accidents, also be l
used?
Westinghouse - The beginning sentence of 'Section 6.2 will be revised to read l
.... prepared for each new system depending on the complexity of the system's safety
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evaluation". The decision to perform a CSA, CSE or ISA always considers factors like system complexity, and risk and consequences of accidents.
- 21. In Subsection 6.2.1, include a complete listing and description of what sections will be included in a CSA.
Westinghouse - The CSA contains a safety analysis (Section 5.3 of an ISA), fault trees (Section 6.3 of an ISA), License Compliance (Section 7 of an ISA), and Appendices as 6
,.,4 necessary (Section 8 of an ISA). Additional sections to upgrade a CSA to a CSE or ISA contain non-criticality safety related material.
- 22. In Subsection 6.2.1 (a), state that you will consider, assess, and document (1) the reliability of each control, (2) the potential common mode failutes of each control, and (3) the margin of safety of each control.
Westinghouse - It is believed that the License as written, combined with the ISA Guidelines, adequately address item 22.
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23.. In Subsection 6.2.1(b), restate to clarify the second sentence (e.g., Section 6.0 of the ISA as described in Chapter 4.0 of this License Application includes...").
Westinghouse - The sentence will be revised to read "Other information which may be contained in Section 6.0, as described in Chapter 4.0 of the license application, includes a HAZOP analysis or What If Checidist."
- 24. In Subsection 6.2.3 (a) through (d), state that validation and verification will occur and be documented, independently reviewed, and signed-off befoce the (1) use of specific hardware and software systems using specific cross section libraries, (2) use of analytical codes, (3) use of the methodology, and (4) qualification and re-qualification of the codes.
Westinghouse - Westinghouse conunits to rewording Subsections 6.2.3 (a) through (d) to better state these requirements.
- 25. Subsection 6.2.3 (d), confirm that a document exists and will be maintained at CFFF that describes the procedure and results used to select the calculations used to determine code operability.
Westinghouse - The NCS handbook will contain this information.
- 26. In Subwection 6.2.4, state the qualifications of the independent qualified reviewer (or place these qualifications elsewhere in the license application) and state that the independent review will be documented. In addition, the 2nd paragraph states, "The technical reviewer will verify." The reviewer can only verify something if it is found to be correct. If the reviewer finds a problem with the original analvals and can not verify it, then he/she violates thu license requirement by NOT verifying it. TI e inteot is clear, but this whole Subsection needs to be worded such that 4 does not imply that verification is automatic, instead of sa),ig that "The technical reviewer will verify," reuse to state that, "The technical reviewer will perform a verification process..." or something similar.
Westinghouse - Only a qualified NCS professional is permitted to perform a technical review. The qualifications are contained in Sections 2.1.3 and 3.1.2 of the License Application.
- 27. In Section 6.3, Table of Plant Systems and Parametric Controlst Clarify how CFFF intends to use Table 6.3.
Westinghouse - The purpose of Table 6.3 'is to reflect the results of the CSAs, CSEs and ISAs being performed for the CFFF.
Confirm that the determinction of separation distances will be used in all situations which require unit separation distances for criticality safety.
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i Westinghouse - Where necessary for establishing nuclear criticality safety with respect to interaction, separation distances will be evaluated.
Commit to (1 ) notifying the NRC within 30 days of changing the table in the case of no decrease in the health and safety of the workers and public and (2) applying for amendment of the license when changing the table in the case of a decrease in the health and safety of the workers or public.
Westinghouse - Concerning commitment (1), it is not clear why Westinghouse should commit to notifying NRC within 30 days of a change in which there is no decrease in the health and safety of the workers and public. Also, a revised license annex resulting from changes to the system ISAs is required to be sent to the NRC within 30 days of completion of the configuration change request for the system.
Concerning commitment (2), it is believed that the provisions for modifications to tid Controlled Parameters covers this request. " Margin of safety" encompasses " health and safety of the workers and public."
Explain how a system can have double contingency protection using a single parameter.
Westinghouse - Double contingency protection on'a single parameter usually takes the form of being able to prevent a credible process upset from occurring and then detecting that process upset should it begin to occur. The DCP for each system is given in the fault tree and evaluation. It is not Westinghouse's understanding that l
Double Contingency Protection as defined in ANSI /ANS 8.1 (1983) necessarily requires more than one controlled parameter. Additional information will be included in the NCS Handbook.
Quantify the entries for " Optimum H2O Moderation."
l Westinghouse - It is not intended to list specific values for each system in this table.
The specfic values are available in the license annex and CSE summaries.
Explain what ' Full Concrete Reflection" is and describe which sides have Partial Reflection.
Westinghouse - Full concrete reflection is modeled as 24" of concrete. The top side of the model uses 1" partial water reflection.
l Explain why there appears to be a disconnect between the text using level control as Favorable Geometry and the table using levei control as Geometry. Modify in relationship with Question 7 Westinghouse - Geometry control as listed in this table reflects the parameter being l
controlled not the method (or type) of control on the parameter.
Quantify the entries for Full Interstitial Moderation."
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Westinghouse - Full interstitial moderation means full density water is present in L
between individual units in the system.
l Explain what is meant by "5 wt. % U" as an evaluation bounding assumption in the table.
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l Wes'inghouse - A density control for 5 wt. % uranium content is being used for these E
f.was;e treatment systems.
. On. page 6.16,' the ' evaluation bounding assumptions for compaction and granulation both assume
= homogeneous UO2. However, according to the new definitions for homogeneous and heterogeneous systems (Subsection 6.1.3 (1)), the compacts made and then broken up in'these two steps seem to fall under the heterogeneous category. Thus, the assumption of homogeneity needs to be reconsidered.
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Westinghouse - The CSE on pelleting does' consider. heterogeneous material as a j
'. bounding assumption in the compaction and granulation processes. Table 6.3 will be revised to show the correct bounding assumption.
Explain the'use 'of two identical processes and equipments with different controlled parameters (e.g., there are two Miscellaneous: Ventilation Systems).
Westinghouse - The controlled. parameters are different because some ventilation systems ventilate dry (s 10 wt. % H O equivalent) systems only and others ventilate 2
'potentially wet (uncontrolled H O) systems,
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2 Specifically, explain the reasons for the deletions, changes, and additions in the table.
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Westinghouse - Generally, revisions are made following the completion of an ISA or
.CSE. As for the differences'between the Revision 1 and Revision 10 tables, many
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CSEs and ISAs have been completed between the two revisions.
- 28. In the License application, define the following terms used in Subsection 6.4.2: " assessments, conduct of operations," and ' Triennially."
Westinghouse ' " Assessment"is another word for review. The assessments to which
'6.4.2 refer to are the process and program reviews. " Conduct of operations" means
.the procedures, practices and controls used in the process. Triennial is defined in Section 1.4 under the definition of FREQUENCIES, Triennial means'once every three
. years, with each covering a span of 45 months or less.
- 29. Subsection 6.4.2, confirm that a complete list of nuclear criticality safety processes used at CFFF is available onsite for NRC review.
Westinghouse - Processes.which require review are those. listed in Table 6.3 of the
. license application.
- 30. In Subsection 6.4.2, state the agreed upon end date for when the development of the ISAs and upgrading of the CSAs and CSEs will be complete.
Westinghouse - The completion date for ISAs is listed in Section 4.0. The completion schedule for updating CSAs and CSEs exists as license approval Safety Condition S-2.
- 31. Subsection 6.42, explain the process of controlling the lower level documents listed so that they do not conflict with the CSA, CSC or ISA at a later date.
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Y Westinghouse - Changes to controlled documents (configuration changes, procedure revisions, drawings, maintenance schedules, etc.) are not made without the appropriate regulatory approval. For those impacting criticality safety evaluations, the criticality
- safety function must approve the change, l
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- 32. In Subsection 6.5.1, provide a description of how CFFF achieves compliance with the ANSI standard and NRC j
Rgulations when they are not the scme.
d" Westinghouse - The ANSI Standard is not regulation. Therefore, where. the NRC regulation differs from the Standard, we will comply with the regulation.
- 33. Explain why Revision 10 has the current license provision of Subsection 6.1.1 (c) as Subsection 6.4.1 with 'or" changed to "and" in the first sentence.
Westinghouse - The "or" was changed to "and" to clarify that the posting contained j
limits and controls rather than one exclusive of the other.
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. 34. Justify why you removed the current license provisions of Subsections 6.1.1 (a), 6.1.1 (b),6.1.2, 6.1.3, the latter parts of 6.2.1 (e.g., verification, maintenance. and functional testing of controls), and 6.3.3. If Revision 10 is approved, where would this information be in the license Application?
i Westinghouse - These sections are redundant. Similar information is already found in Sections 3 of.the license application. A revision to Section 3 was previously provided for review such that information removed from Section 6 would be contained in Section 3.
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