ML20137B897
| ML20137B897 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 03/18/1997 |
| From: | Muench R WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20137B901 | List: |
| References | |
| ET-97-0013, ET-97-13, NUDOCS 9703240097 | |
| Download: ML20137B897 (12) | |
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NUCLEAR OPERATING CORPORATION Richard A. Muench Vice President Engineering March 18, 1997 ET 97-0013 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-13' Washington, D.
C.
20555
Subject:
Docket No. 50-482: Proposed Revision to Technical Specification Surveillance Requirement 4.5.2.c, Containment Visual Inspection Gentlemen:
This letter transmits an application for amendment to Facility Operating License No. NPF-42 for Wolf Creek Generating Station (WCGS).
This license amendment request revises Technical Specification Surveillance Requirement 4.5.2.c to clarify when a containment entry visual inspection is required.
This proposed ~
change to reduce the visual inspection requirement to at least once daily is in accordance with the guidance provided in Generic Letter 93-05, "Line-Item Technical Specifications Improvements to Reduce Surveillance Requirements for Testing During Power Operation."
Since this proposed change would affect refueling outage activities, it is requested that this proposed revision be approved and issued prior to September 30, 1997, in order to support startap from the WCGS ninth refueling outage.
A Safety Evaluation for the proposed change is provided in Attachment I,
and Attachment II provides a No Significant Hazards Consideration Determination.
Attachment III is the Environmental Impact Determination for the proposed change, and the marked-up technical specification page for this request is provided in Attachment IV.
/)o 9703240097 970318 PDR ADOCK 05000482 hhNhlb:h.h!hi P
pon.
PO. Box 411/ Burhngton, KS 66839 / Phone: (316) 364-8831 An Equa: Opportunity Employer M T HCVET
,ET 97-0013 Page 2 of 2 In accordance with 10 CFR 50.91, a copy of this application, with attachments, l
is being provided to the designated Kansas State Official.
If you have any questions concerning this matter, please contact me at (316) 364-8831, extension 4034, or Mr. Richard D.
Flannigan, at extension 4500.
Very truly yours, Richard A. Muench RAM /jad Attachments I
- Safety Evaluation II - No Significant Hazards Consideration Determination i
III - Environmental Impact Determination
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IV - Proposed Technical Specification Change j
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cca V. L.
Cooper (KDHE), w/a E.
W.
Merschoff (NRC), w/a W.
D.
Johnson (NRC), w/a J.
F. Ringwald (NRC), w/a J.
C.
Stone (NRC), w/a i
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STATE OF KANSAS
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. COUNTY OF COFFEY
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l Richar'd A. Muench, of lawful age, being first duly sworn upon oath says that' he is Vice President Engineering of Wolf Creek Nuclear Operating Corporation; that he has read the foregoing document and knows the content thereof; that l
he has executed that. same for and on behalf of said Corporation., with full power and authority to do so; and that the facts therein stated'are true and correct to the best of his knowledge, information and belief.
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By l
Richard &. Muench.
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Vice' President-Engineering-l l
SUBSCRIBED and sworn to before me this
/8 day of ]T/M, 1997.
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. ANGELA E.WESSEL N tary Ppblic NotaryPubf!- Stateofl(ansas l
Mv Appt. Expires 0 7/03/ 9 9 j Expiration Date I,3-99 i
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4 Atttchment I to ET 97-0013 pig 2 1 of 4 0
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ATTACHMENT I SAFETY EVALUATION 1
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Attcchm:nt I to ET 97-0013 Pege 2 of 4 Safety Evaluation Ergposed changa This license amendment request proposes to revise the Wolf Creek Generating Station (WCGS) Technical Specifications to clarify the time requirement for performing a containment entry visual inspection for loose debris.
The specific change to Technical Specification Surveillance Requirement 4.5.2c.2 is to revise the requirement to state "At least once daily of the areas affected within containment by containment entry and during the final entry when CONTAINMENT INTEGRITY is established."
l Rackground On September 27,
- 1993, the NRC issued Generic Letter 93-05, "Line-Item
'"echnical Specifications Improvements to Reduce Surveillance Requirements for Testing During Power Operation."
This Generic Letter provides guidance to Licensees for preparing license amendment requests to implement recommendations from NUREG-1366,
" Improvements to Technical Specifications Surveillance Requirements."
Generic Letter 93-05 Line Item 7.5,
" Visual Inspection of the Containment Sump (PWR),"
addresses the NUREG-1366 i
recommendation to revise che wording in Technical Specification Surveillance Requirement 4.5.2c.2 (based on the CE Standard Technical Specifications, which was typical of all the Standard Technical Specifications). The purpose of the rewording is to clarify that the visual inspection for loose debris is to be performed daily in areas affected by containment entry, and is to be performed during the final entry when containment integrity is established.
As discussed in Generic Letter 93-05, the Standard Technical Specification wording implied that a separate containment entry would have to be made following completion of each containment entry, in order to perform the required visual inspection.
WCGS Technical Specification Surveillance Requirement 4.5.2c.2 currently states "Of the areas affected within containment at the completion of each containment entry when CONTAINMENT INTEGRITY is established."
This is the same as the wording from the Standard Technical Specifications that was recommended to be changed in NUREG-1366.
Wolf Creek Nuclear Operating Corporation (WCNOC) proposes to revise this requirement to state "At least once daily of the areas affected within containment by containment entry and during the final entry when CONTAINMENT INTEGRITY is established."
This is the change recommended in Generic Letter 93-05.
Ey.aluation l
The current wording of WCGS Technical Specification Surveillance Requirement 4.5.2c.2 implies that a second containment entry must be made after completing each containment entry in order to perform a visual inspection of the containment for loose debris that could be transported to the containment sumps and cause restrictions to sump suction during loss-of-coolant-accident (LOCA) conditions.
This effectively requires that a separate containment
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1 Attstchmint I to ET 97-0013 Pega 3 of 4 0
I entry to perform the visual inspection be made for each entry made in a day (i.e.,
one containment entry would require one additional entry, two containment entries on the same day would require two additional entries, etc.).
This requirement imposes a resource restraint due to the extra containment entries and associated personnel time and exposure, particularly when starting up from an outage, that is not commensurate with the safety impact of the additional inspections.
The numoer of additional containment entries to perform visual inspections becomes particularly excessive when starting up from an outage due to the number of containment entries required to perform inspections and equipment surveillances in preparation for operating Mode changes.
This, in turn, requires excessive cycling of the personnel airlock doors and door seals and testing of the door seals to ensure airlock integrity following opening / closing of the airlock.
The proposed change would more clearly indicate that a single containment visual inspection for loose debris could be performed for multiple containment entries made on the same day, and would also allow the visual inspection to be performed during the last containment entry made on that day, instead of making a separate containment entry just to perform the required visual j
inspection.
When evaluating Generic Letter 93-05 Line Item 7.5 for applicability to WCGS, consideration was given to the potential effects on sump operation of performing the visual inspection only once per day.
The purpose of the i
inspection is to identify and remove any loose debris (rags, trash, clothing, etc.) after the completion of any activity involving a containment entry.
Loose debris left in containment could potentially be transported to the sumps and clog the sump screens during a LOCA.
Performing this inspection only once i
per day for multiple entries introduces the potential for loose debris from an i
early entry to be left in containment and not removed until later in the day.
The design of the WCGS containment sumps provides a baffle arrangement consisting of grating, coarse screening, and fine screening completely surrounding the sumps to prevent floating debris and high-density particles from entering the sumps.
The grating is placed as the outermost barrier and is used to keep large debris off the screens.
The next barrier is coarse industrial wire mesh screening which has a 1/2-inch maximum opening.
The inner barrier is fine industrial wire mesh screening which has a 1/8-inch maximum opening.
The attachment of the screening to the support structure is designed to keep debris from bypassing the screening.
As discussed in Section 6.2.2.1.2.2 of the WCGS Updated Safety Analysis Report (USAR), the containment sump screens were sized in accordance with the recommendations of Regulatory Guide 1.82, " Sump for Emergency Core Cooling and Containment Spray Systems," which assumes a 50 percent blockage of these i
screens.
USAR Section 6.2.2.1.3 also discusses that the sump screen supports j
are designed to withstand the differential pressure that would exist if the screens were to become 100 percent clogged, and that sufficient screen area exists to allow over 50 percent clogging of both sump screens without degrading containment spray pump net positive suction head (NPSH).
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l-AttachmInt I to ET 97-0013 Paga 4'of 4 e
l Debris generated as a result of a LOCA will either be retained in an area such I
l as the reactor cavity or ' refueling pool, or must follow a tortuous path to i
j reach the recirculation sump screens.
The sump baffle arrangement-does not allow flow into the sump below 6 inches above the concrete floor level surrounding the sump.
This arrangement leaves ample depth for buildup of high-density debris without affecting sump performance.
Additionally, the l
l velocity of recirculated fluids approaching the trash rack will be between l
0.01 and 0.08 fps -for all modes of operation following a LOCA or main steam
-line' break (MSLB), and thus a low velocity settling region for high-density l
particles is provided.
Therefore, no appreciable debris will reach the l
recirculation sump screens to cause any significant blockage.
J WCNOC's work control process and employee Plant Access Training stresses the
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importance of maintaining containment cleanliness and accountability of materials entering and leaving containment, to reduce the amount of waste in radiologically-controlled areas, and to be aware of and to properly dispose of
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trash or debris in these areas.
In addition, Health Physics technicians j
frequently accompany maintenance / repair crews during containment entries, and provide an additional level of awareness of trash and debris generated by these activities.
Additional oversight of ' activities inside containment during outages is provided by Containment Coordinators, who provide an ongoing housekeeping evaluation ' to ensure that trash.and debris are appropriately removed on a daily basis.
Results of previously performed containment visual inspections indicate. that no significant occurrences of loose debris were identified during these surveillances, i
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Baced on the above evaluation, the proposed change is consistent with the I
guidance of Generic Letter 93-05 and with plant operating experience.
Based on the above discussions and the no significant hazards ' consideration
'n Attachment II, the proposed change does not determination presented i
increase the probability of occurrence or the consequences of an accident or 1
malfunction of equipment important to safety previously evaluated in the j
safety analysis report; or create a possibility for an accident or malfunction of a different type than any previously evaluated in the safety analysis
- report; or ' reduce the margin of safety as defined in the basis for any technical specification.
Therefore, the proposed change does not adversely affect or endanger the health or safety of the general public or involve a l
significant safety hazard, e
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1 AttichmInt III to ET 97-0013 i
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l ATTACHMENT II NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION i
l Attachm:nt III to ET 97-0013 Paga 2 of 3 l
No Significant Hazards Consideration Determination 5
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This license amendment request proposes to revise the Wolf Creek Generating l
Station (WCGS) Technical Specifications to clarify the time requirement for r
performing a containment entry visual inspection for loose debris, i
1 The specific change to Technical Specification Surveillance Requirement L
4.5.2c.2 is to revise the requirement to state "At least once daily of the i
areas affected within containment by containment entry and during the final entry when CONTAINMENT INTEGRITY is established."
This proposed change would allow a single visual inspection for loose debris to be performed during the final containment entry made each day.
The current surveillance requirement, as worded, implies that a separate containment entry to perform the visual inspection must be made following each containment entry.
Under certain conditions (i.e.,
on days when multiple containment entries are made) this would require several additional containment entries to be made just to perform the required visual inspections.
This proposed change to reduce the i
visual inspection requirement to at least once daily is in accordance with the guidance provided in Generic Letter 93-05, "Line-Item Technical Specifications Improvements to Reduce Surveillance Requirements for Testing During Power Operation."
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Standard I - Involve a
Significant Increase in the Probability or Consequences of an Accident Previously Evaluated Implementing the proposed change could potentially increase the chances of loose debris (trash, rags, clothing, etc.) being left in containment for some period of time greater than would be allowed under _ current surveillance e
requirements.
However, the proposed change also clarifies that the visual inspection must be performed at least once daily.
Therefore, the period of time that debris could be left uncontrolled inside containment would still be less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Based on work controls placed on material entry / exit into i
containment and personnel training on housekeeping controls inside containment, and the results of past surveillances, it is unlikely that a significant amount of debris would be left uncontrolled inside containment for this period of time. Also, based on containment sump design, relatively small amounts of debris would not be sufficient to cause a significant amount of blockage of the sump screens.
The probability of occurrence of a previously evaluated accident is not increased because the reduced frequency of the visual inspection does not l
cause a significant impact on the possibility of containment sump screen blockage.
Therefore containment sump operability is not affected by the l
proposed change.
In addition, the proposed change will not result in any changes to the design or operation of any plant systems or components i
Standard II - Create'the Possibility of a New or Different Kind of Accident from any Previously Evaluated The proposed change decreases the frequency of performing a visual inspection for loose debris in containment, but does not result in a change to the design
Attcchm:nt III to ET 97-0013 I
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or operation of any plant system or component.
The purpose of the inspection is to ensure that there is no loose debris, left in containment following a containment entry, that could potentially block the containment sump screens during LOCA conditions.
Delaying this inspection until the last containment entry each day will not result in a significant amount of debris being left in containment, based on the housekeeping practices controlling the entry / removal of trash and material into/from containment; training of employees to increase awareness of material control in radiologically-controlled areas; and retaining the requirement to perform a visual inspection at least once per day when containment entries are made (during periods when containment integrity is established), thereby ensuring that trash and debris can be identified and removed on a daily basis (on days containment entries are made).
Based on the above, this proposed change will not create the possibility of a new or different kind of accident from any previously evaluated.
Standard III - Involve a Significant Reduction in the Margin of Safety The purpose of performing a visual inspection of areas affected by a containment entry is to ensure any debris or trash generated by the activity during the containment entry is identified and removed from containment.
This ensures that no trash or debris is left in containment that could be transported to and block the containment sump screens during LOCA conditions.
Based on current material control and housekeeping practices imposed. on containment entry / exit, and past inspection results, reducing the surveillance requirement to a once per day basis, on days containment entries are made, would not result in a significant amount of trash or debris being left in containment following completion of the entry, and any such material would be identified and removed prior to the end of the day.
The amount of trash or debris that could be left in containment for a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period would be significantly less than the amount that would be required to cause sump screen blockage sufficient to affect sump performance.
Therefore, the proposed change will not result in a significant reduction in the margin of safety of any plant system or equipment.
Based on the above discussions, it has been determined that the requested technical specification revision does not involve a significant increase in the probability or consequences of an accident or other adverse condition over previous evaluations; or create the possibility of a new or different kind of accident or condition over previous evaluations; or involve a significant reduction in a margin of safety.
Thus, the requested license amendment does not involve a significant hazards consideration.
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Attschm:nt III to ET 97-0013 Prga 1 of 2
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S ATTACHMENT III ENVIRONMENTAL IMPACT DETERMINATION
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l Attachment III to ET 97-0013 l
PEga 2 of 2 Environmental Impact Determination l
10 CFR 51. 22 (b) specifies the criteria for categorical exclusions from the i
requirement for a specific environmental assessment per 10 CFR 51.21.
This amendment request meets the criteria specified in 10 CFR
- 51. 22 (c) (9) as specified below:
(i) the amendment involves no significant hazards consideration As demonstrated in Attachment II, the proposed change does not involve any significant hazards consideration.
l (ii) there is no significant change in the types or significant increase in the amounts of any effluents that may be released offsite The proposed change does not involve a change to the facility or operating procedures that would cause an increase in the amounts of effluents or create new types of effluents.
(iii) there is no significant increase in individual or cumulative occupational radiation exposure The proposed change does not create additional exposure to personnel nor l
affect levels of radiation present. Also, the proposed change does not result l
in any increase in individual or cumulative occupational radiation exposure.
In fact, the reduction in the number of containment entries required by the revised surveillance requirement will result in a decrease in personnel radiation exposure.
Based on the above it is concluded that there will be no impact on the environment resulting from this change and the change meets the criteria specified in 10 CFR 51.22 for a categorical exclusion from the requirements of
'10 CFR 51.21 relative to requiring a specific environmental assessment by the Commission.
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