ML11312A051
| ML11312A051 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 10/28/2011 |
| From: | Rich Smith Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2.11.040, IR-06-006, TAC MC54199, TAC MC9018 | |
| Download: ML11312A051 (11) | |
Text
Entergy Entergy Nuclear Operations, Inc.
Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth, MA 02360 Robert G. Smith, P.E.
Site Vice President October 28, 2011 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Entergy Nuclear Operations, Inc.
Pilgrim Nuclear Power Station Docket No. 50-293 License No. DPR-35
REFERENCES:
Proposed License Amendment: Revision to Technical Specification (TS)
Table 3.2.B for the Condensate Storage Tank (CST) Low Level Trip Setpoint and Corrections to Typographical Errors Incurred During Prior License Amendment Nos. 223 and 228
- 1.
Pilgrim Nuclear Power Station-NRC Inspection Report 05000293/2006006, dated June 29, 2006
- 2.
Pilgrim Nuclear Power Station-Issuance of Amendment Re:
Administrative Changes and Relocation of Certain Technical Specification Responsibilities (TAC NO. MC 5419), dated August 9, 2006
- 3.
Pilgrim Nuclear Power Station-Issuance of Amendment Re: Single Rod Withdrawal Allowances (TAC NO. MC 9018), dated April 25, 2007 LETTER NUMBER:
2.11.040
Dear Sir or Madam:
Pursuant to 10 CFR 50.90, Entergy Nuclear Operations, Inc. (Entergy) hereby requests an amendment to the Pilgrim Operating License Technical Specifications (TS).
The proposed amendment (a) increases the condensate storage tank low water level setpoint for the interlock to the High Pressure Coolant Injection (HPCI) pump suction valves and (b) corrects Technical Specification numbering and referencing typographical errors made in the prior License Amendments Nos. 223 and 228.
AoO
Entergy Nuclear Operations, Inc Letter Number 2.11.040 Pilgrim Nuclear Power Station Page 2 of 2 to this letter provides "Evaluation of Proposed TS Changes" and Attachment 2 provides "Marked-up pages of the current TS and Bases".
The marked-up Technical Specification BASES pages are provided for information only.
Entergy requests NRC approval of the proposed Pilgrim TS amendment by September 30, 2012. Once approved, the amendment will be implemented within 60 days.
This letter contains no new regulatory commitments.
If you have any questions regarding the subject matter, please contact Joseph R. Lynch at (508) 830-8403.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on the
.2-8 day of 0 r 6
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,2011.
Sincerely, Robert G. Smith, P.E.
Site Vice President : Evaluation of Proposed TS Changes (36 pages). : Marked-up Pages of the Current TS and Bases (7 pages).
cc:
Mr. Richard Guzman, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission One White Flint North O-8C2 11555 Rockville Pike Rockville, MD 20852 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 NRC Resident Inspector Pilgrim Nuclear Power Station John Giarrvsse, Jr.
Planning and Preparedness Section Chief Mass Emergency Management Agency (MEMA) 400 Worcester Road Framingham, MA 01702 Robert Gallaghar, Acting Director, Massachusetts Department of Public Health (MDPH)
Radiation Control Program Commonwealth of Massachusetts 529 Main Street, Suite 1M2A Charlestown, MA 02129-1121 to Entergy Letter 2.11.040 Evaluation of Proposed TS Changes Evaluation of Proposed TS Changes
- 1.
DESCRIPTION
- 2.
PROPOSED CHANGES
- 3.
BACKGROUND
- 4.
TECHNICAL ANALYSIS
- 5.
REGULATORY SAFETY ANALYSIS 5.1 No Significant Hazards Consideration 5.2 Applicable Regulatory Requirements/Criteria
- 6.
ENVIRONMENTAL CONSIDERATION
- 7.
COORDINATION WITH PENDING TS CHANGE REQUESTS
- 8.
REFERENCES
- 9.
ATTACHMENT Page 1 of 9 to Entergy Letter 2.11.040 Evaluation of Proposed TS Changes
1.0 DESCRIPTION
Pursuant to 10 CFR 50.90, Entergy Nuclear Operations, Inc. (Entergy) hereby requests an amendment to the Pilgrim Operating License Technical Specifications (TS) to (a) increase the condensate storage tank low water level setpoint for High Pressure Coolant Injection (HPCI) pump suction valves and (b) to correct Technical Specification numbering referencing typographical errors made in the prior License Amendments Nos. 223 and 228.
The proposed changes to the Technical Specifications are as follows:
TS Table 3.2.B, page 3/4.2-15, the trip level setting for the Condensate Storage Tank (CST) Low Water Level is changed from "> 18" above tank zero" to "> 46" above tank zero". This proposed change corrects the inspection finding documented in Reference 1 (NCV 05000293/2006006-01, Less Than Adequate Design Control Associated with Potential CST Vortexing). This is a TS and a Licensing Bases change.
A typographical error was introduced on the marked-up TS pages 3/4.13 -1 and 2, which was carried forth to the re-typed TS pages, and ultimately issuance of License Amendment 223, "Administrative Changes and Relocation of Certain Technical Specifications", dated August 17, 2006. The error is under TS section 4.13.A, where the surveillances should have been sequentially numbered as 1, 2, 3, and 4; instead the surveillances were numbered as 1, 3, 4, and 5 (omitting 2).
The omission of chronological number "2" created a numbering sequence error.
This error is being corrected on TS Pages 3/4.13 -2 by sequentially numbering the surveillances. This is an administrative change.
A typographical error was introduced on the mark-up of TS pages and TS Bases pages for License Amendment 228, "Single Control Rod Withdrawal Allowances, TS 3/4.14, Special Operations", dated April 25, 2007. Prior to the License Amendment 228, TS Section 3.10.D addressed Specifications related to refueling conditions, which allowed multiple control rod removal. By License Amendment 228, the refueling conditions were relocated to TS Section 3/4.14.E, as "Multiple Control Rod Removal", but not all mark-ups were made consistently for the License Amendment 228. Thus, TS LCO 3.3.B.1 APPLICABILITY statement provides an incorrect reference to TS Section 3.10.D. TS BASES 3.10.A also makes incorrect reference to 3.10.D Both TS LCO 3.3.B.1 and TS BASES 3.10.A should refer to TS Section 3/4.14.E, since TS Section 3/4.10.D was relocated to TS Section 3/4.14.E.
By this proposed License Amendment, these typographical errors are corrected making reference to the correct TS Sections. This is an administrative change.
2.0 PROPOSED CHANGE
S provides marked-up of current Pilgrim Technical Specifications pages and TS BASES pages.
Condensate Storage Tank Low Level Trip Level Setting is changed from ">- 18" above tank zero" to "> 46" above tank zero" on TS Table 3.2.B, Page 3/4.2-16.
Page 2 of 9 to Entergy Letter 2.11.040 Evaluation of Proposed TS Chanqes The "Inservice Code Testing" surveillance requirements are sequentially numbered as 1, 2, 3, and 4 under TS Section 4.13, TS Pages 3/4.13-1, and TS Page 3/4.13-2 is marked as "Intentionally Left Blank". This corrects the typographical error made during the License Amendment 223.
The TS LCO 3.3.B.1 APPLICABILTY is being corrected to state in parenthesis from
"(See also 3.10.D)" to "(See also 3/4.14.E)" on TS Page 3/4.3-2. The reference to LCO 3.10.D in the BASES section 3.10, "Core Alterations" is corrected to LCO 3/4.14.E on Pages B3/4.10-1 and on page B3/4.10-3 references to "Specification to 3.10.D" is corrected to "Specification 3/4.14E".
These changes correct the typographical errors made during the License Amendment 228.
The BASES pages are provided for NRC information only. TS BASES changes will be incorporated into TS upon receipt of the NRC approved License Amendment in accordance with TS 5.5.6, BASES Control Program.
3.0 BACKGROUND
3.1 Condensate Storage Tank (CST) Low Water Level Trip Setting:
This license amendment request proposes to increase the HPCI low CST level allowable value to > 46 inches from the current value of > 18 inches in Technical Specification Table 3.2.B. The allowable value of > 18 inches is not conservative based on recently developed information.
During the CDBI inspection in 2006, a low safety significance NCV was identified by the NRC inspection team that Entergy used a non-conservative calculation method to determine the critical condensate storage tank (CST) water level which would preclude vortex formation at the suction of the HPCI pump [Ref. 1]. The NRC inspection team observed that Entergy determined the critical tank level to preclude vortex formation was 14 inches above the tank bottom, based on a graph given in a 1969 Oil and Gas Trade Journal article. The team questioned the validity of the 14 inch critical tank level based on a comparison with the higher critical tank levels obtained using other independent methodologies such as 33 inches using Reddy-Pickford [Ref.
4], and 54 inches using the Hydraulic Institute Standard [Ref. 5]. The critical tank level of 14 inches had been used as the analytical limit in the setpoint calculation for the HPCI CST low level Technical Specification allowable value of >18 inches and instrument trip setpoint of 36 inches in use at the time of the inspection [Ref. 8].
Resolution to the Issue:
In recognition of the non-conservative critical water level, Entergy personnel initiated a condition report to evaluate the condition and to implement interim corrective actions to address the vortexing concern.
The associated Entergy operability determination directed procedure changes to manually swap the HPCI suction from the CST to the torus at a tank level of eight feet and required operators to maintain both CSTs cross-tied and available (maximizing CST available inventory and minimizing vortexing potential).
The tank level manual swap requirement of eight feet was established to protect a critical water level calculated using the Reddy-Pickford relationship with an ample time allowance for operator action.
The NRC inspection team determined that this design control deficiency did not result in a loss of HPCI's safety function. This conclusion was based on the following: the current instrument setpoint (36 inches); the administratively controlled CST levels are well above the critical water level; normal operation is with cross-tied CSTs; there is an automatic swap-over on high torus level; the installed CST low level alarms (12.5 feet); and available operator action time. The procedure Page 3 of 9 to Entergy Letter 2.11.040 Evaluation of Proposed TS Changes changes were implemented as interim corrective actions until a more permanent solution was developed.
Corrective actions for the inspection finding included testing on a scale model of a single CST at Alden Research Laboratory to establish the critical water level to preclude air ingestion from vortices [Ref. 6].
Entergy calculated a trip setpoint of 58 inches and Technical Specification allowable value of > 46 inches for the HPCI suction transfer on low CST water level based on the model test results, flow rate uncertainties, initiating signal time delay, valve operating times, and instrument setpoint methodology [Ref. 7 & 9]. An engineering change was implemented that increased the setpoint from 36 inches to 58 inches [Ref. 10].
3.2 Typographical Error During License Amendment 223:
A typographical error was introduced on the marked-up TS pages 3/4.13-1 and 2, which was carried forth to the re-typed TS pages, and ultimately issuance of License Amendment 223, "Administrative Changes and Relocation of Certain Technical Specifications", dated August 17, 2006 (Reference 2). The error is under TS section 4.13.A, where the surveillances should have been sequentially numbered as 1, 2, 3, and 4, and instead the surveillances were numbered as 1, 3, 4, and 5 (omitting 2). The omission of chronological number "2" created a numbering sequence error. This error is being corrected TS Pages 3/4.13-2 by sequentially numbering the surveillances. This is an administrative change.
3.3 Typographical Error During License Amendment 228:
A typographical error was introduced on the mark-up of TS pages and TS Bases pages for License Amendment 228, "Single Control Rod Withdrawal Allowances, TS 3/4.14, Special Operations", dated April 25, 2007 (Reference 3).
Prior to the License Amendment 228, TS Section 3.10.D addressed Specifications related to refueling conditions, which allowed multiple control rod removal. By License Amendment 228, the refueling conditions were relocated to TS Section 3/4.14 E, as "Multiple Control Rod Removal", but not all mark-ups were made for the License Amendment 228.
Thus, TS LCO 3.3.B.1 APPLICABILITY statement provides an incorrect reference to TS Section 3.10.D. TS BASES 3.10.A also makes incorrect reference to 3.10.D Both TS LCO 3.3.B.1 and TS BASES 3.10.A should refer to TS Section 3/4.14.E, since TS Section 3/4.10.D was relocated to TS Section 3/4.14.E via License Amendment 228 in April 2007. By this proposed License Amendment, these typographical errors are corrected making reference to the correct TS Sections. This is an administrative change.
4.0 TECHINCIAL ANALYSIS Description of plant arrangement HPCI and RCIC are normally aligned to both condensate storage tanks (CSTs) which contain reactor quality water and are the preferred water source for reactor makeup. HPCI and RCIC share a common suction located on the bottom of each CST. Two tanks are installed to allow maintenance on one CST when HPCI and RCIC are required to be operable. The proposed Technical Specification allowable value is selected based on operation of both HPCI and RCIC with a single CST in-service.
Each CST has the following characteristics:
cylindrical shape, 35 feet in diameter and 39.5 feet tall between the tank bottom and overflow pipe entrance, Page 4 of 9 to Entergy Letter 2.11.040 Evaluation of Proposed TS Changes nominal water capacity of 275,000 gallons, instrument zero is located at tank bottom, a vertical 18 inch diameter (17.25 inch ID) common suction nozzle for the HPCI and RCIC pumps draws flow from the bottom of the tank, suction pipe entrance centerline is located 12.5 feet from the tank center, all other suctions are located above the HPCI and RCIC suction to provide a nominal 75,000 gallon reserve in each tank for these systems,
" torus provides the backup emergency suction supply.
Low level in the Condensate Storage Tank (CST) causes HPCI to transfer its suction from the CST to the Torus. There are three valves in the HPCI suction.. One valve lines up pump suction from the CST, the other two from the Torus. If water level in the CST falls below the minimum level, the Torus suction valves automatically open after a time delay. When the Torus suction valves are both fully open, the CST suction valve automatically closes.
Two pressure switches are used to detect the CST low water level condition and initiate a suction transfer that is completed before vortexing/air-entrainment occurs due to the low water level condition. The pressure switches sense pressure in the HPCI suction line from the CST.
Either switch can cause the Torus suction valves to open. A short time delay is included in the Torus suction valves opening circuit to prevent false/transient signals from initiating suction valve transfer.
To establish the critical tank water level to avoid vortexing/air-entrainment a physical hydraulic model study of a single CST was conducted at Alden Research Laboratory by Entergy contractor AREVA. The testing was done to evaluate the potential for vortexing/air-entrainment at specified flow rates as the tank drains and the water level is lowered. The criteria used in the model study to establish the critical water level was the commencement of air bubbles being drawn from the water surface into the suction. The model study measured a critical tank water level which is equivalent to 2.41 feet above tank bottom at 4650 gpm, the combined flow rate of HPCI (4250 gpm) and RCIC (400 gpm). The model study is described fully in a proprietary AREVA report [Ref. 6].
Entergy adjusted (increased) the critical tank water level from the model testing to account for flow measurement uncertainty of the HPCI and RCIC system flow controls and the CST level decrease that will occur at maximum flow rate while the suction valves change position after the pressure switches initiate HPCI suction transfer to the torus. This height adjustment increased the critical tank water level by 1.13 feet, raising the critical tank water level from model testing of 2.41 feet to 3.54 feet (43 inches). The critical tank water level of 43 inches was established as the analytical limit for use in the instrument uncertainty calculation Entergy prepared to determine the pressure switch trip setpoint and the proposed Technical Specification allowable value [Ref. 9].
The instrument uncertainty calculation accounts for instrument loop characteristics including potential instrument drift, seismic effects, temperature effects, as-found tolerance, and as-left tolerance. The total loop uncertainty is equivalent to 15 inches of water level which establishes a trip setpoint of 58 inches (e.g., analytical limit of 43 inches plus 15 inches). The proposed Technical Specification allowable value of >46 inches is calculated by subtracting the SRSS combination of the as-left tolerance and drift allowances from the trip setpoint of 58 inches. The proposed Technical Specification allowable value of >46 inches precludes vortexing/air-entrainment in the HPCI suction by initiating transfer to the torus sufficiently above the critical water level where air begins to be drawn into the suction. The instrument loop uncertainty calculation Reference 9 is provided with this submittal as Attachment 9.0, item 1.
Page 5 of 9 to Entergy Letter 2.11.040 Evaluation of Proposed TS Changes
5.0 REGULATORY ANALYSIS
5.1 No Significant Hazards Consideration Entergy requests a License Amendment to Pilgrim Operating License Technical Specifications (TS) to make the following changes:
increase the Condensate Storage Tank Low Water Trip Level Setting from "> 18 inches above tank zero" to "> 46 inches above tank zero" on TS Table 3.2.B, Page 3/4.2-16, to resolve a design deficiency inspection finding, that would provide water supply for HPCI pump operation to mitigate accident conditions.
correct typographical errors introduced on the marked-up TS pages 3/4.13 -1 and 2, which were carried forth to the re-typed TS pages, and ultimately issuance of License Amendment 223, "Administrative Changes and Relocation of Certain Technical Specifications", dated August 17, 2006.
" correct typographical errors introduced on the mark-up TS pages and TS Bases pages for License Amendment 228, "Single Control Rod Withdrawal Allowances, TS 3/4.14, Special Operations" dated April 25, 2007, which made incorrect references to TS Section 3.10.D in TS LCO 3.3.B.1 APPLICABILITY statement and in TS BASES 3.10.A instead of correct reference to TS Section 3/4.14.E. The corrections of typographical errors are administrative changes.
Entergy has evaluated the proposed Pilgrim TS changes using the criteria in 10 CFR 50.92, and has determined that the proposed changes do not involve a significant hazards consideration. The following information is provided to support a finding of no significant hazards consideration determination.
- 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The increasing of the setpoint for the Condensate Storage Tank (CST) low water level High Pressure Coolant Injection (HPCI) System automatic suction transfer to the Suppression Pool is not a precursor to any accident previously evaluated. The CST is not utilized to mitigate the consequences of any accident previously evaluated. The increase in the setpoint provides for HPCI pump performance with the required flow to mitigate the accident conditions. The proposed corrections to typographical errors incurred in the prior License Amendments provide correct references to the applicable existing Specifications, which is an administrative change.
The proposed changes do not involve a change to the safety function of the HPCI system operation. The proposed TS revision involves no significant changes to the operation of any systems or components in normal or accident operating conditions.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2.
Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
Page 6 of 9 to Enterqy Letter 2.11.040 Evaluation of Proposed TS Changqes Response: No The increasing of the setpoint for the Condensate Storage Tank (CST) low water level High Pressure Coolant Injection (HPCI) System automatic suction transfer to the Suppression Pool is not a precursor to any accident previously evaluated. The CST is not utilized to mitigate the consequences of any accident previously evaluated. The increase in the setpoint provides for HPCI pump performance with the required flow to mitigate the accident conditions. The proposed corrections to typographical errors incurred in the prior License Amendments provide correct references to the applicable existing Specifications, which is an administrative change.
The proposed changes do not change the safety function of the HPCI and RCIC systems. There is no alteration to the parameters within which the plant is normally operated. The increase in the setpoint is not a precursor to new or different kind of accidents and do not initiate new or different kind of accidents. The impact of these changes have been analyzed and found to be acceptable within the design limits and plant operating procedures. As a result, no new failure modes are being introduced.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
- 3.
Does the proposed change involve a significant reduction in a margin of safety?
Response: No The margin of safety is established through the design of the plant structures, systems, and components, the parameters within which the plant is operated and the establishment of the setpoints for the actuation of equipment relied upon to respond to an event and design basis accidents. The proposed change increases the setpoint at which protective actions are initiated, and but does not change the requirements governing operation or availability of safety equipment assumed to operate to preserve the margin of safety. The corrections to the typographical errors introduced in the prior License Amendments do not impact the safety margin.
Therefore, the proposed change does not involve a significant reduction in the margin of safety.
Based upon the above, Pilgrim concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92 (c), and, accordingly, a finding of no significant hazards consideration is justified.
5.2 Applicable Regulatory Requirements and Criteria 10 CFR 50, Appendix A provides criteria for Emergency Core Cooling System (ECCS) performance and 10 CFR 50.36, Technical Specifications, requires safety system settings to ensure the integrity of the reactor pressure boundary during normal and abnormal operations and to mitigate transient and accident conditions. The proposed increase in the condensate storage tank low water level setpoint follows the requirements cited above.
In conclusion, based on the considerations discussed above, (1) there is a reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the NRC's Page 7 of 9 to Entergy Letter 2.11.040 Evaluation of Proposed TS Changes regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
6.0 ENVIRONMENTAL CONSIDERATION
Entergy has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, "Standards for Protection Against Radiation." However, the proposed amendment does not involve: (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.
Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22, "Criterion for Categorical Exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review", Paragraph (c)(9). Therefore, in accordance with 10 CFR 51.22, Paragraph (b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.
7.0 COORDINATION WITH PENDING TS CHANGES There are no pending proposed TS changes that are being filed for license amendment that would impact the proposed TS changes.
8.0 REFERENCES
- 1. Pilgrim Nuclear Power Station-NRC Inspection Report 05000293/2006006, dated June 29, 2006
- 2. Pilgrim Nuclear Power Station-Issuance of Amendment Re: Administrative Changes and Relocation of Certain Technical Specification Responsibilities (TAC NO. MC 5419),
dated August 9, 2006
- 3. Pilgrim Nuclear Power Station-Issuance of Amendment Re: Single Rod Withdrawal Allowances (TAC NO. MC 9018), dated April 25, 2007
- 4. Reddy, Y.R. and Pickford, J.A. (1972) "Vortices at intakes in conventional sumps," Water Power 24(4) 108-109
- 5. ANSI/HI 9.8-1998, "American National Standard for Pump Intake Design," Hydraulic Institute, 1998
- 6. Report 51-9117255-000, "Pilgrim CST Suction Test Report, The Evaluation of Potential for Vortexing/Air Entrainment Using a Physical Hydraulic Model", Areva NP Inc., Rev. 0
[PROPRIETARY].
- 7. Calculation M501, Minimum CST Level for Transfer of HPCI Pump Suction to Torus, Rev. 1, 10/14/2009
- 8. Calculation IN1-245, "Setpoint Calculation for PS-2390A & B, Condensate Tank Low Level Transfer"', Rev. 0
- 9. Calculation IN1-245, "Setpoint Calculation for PS-2390A & B, Condensate Tank Low Level Transfer", Rev. 2, 10/7/2009 Page 8 of 9 to Enterqy Letter 2.11.040 Evaluation of Proposed TS Changes
- 1. Calculation IN1-245, "Setpoint Calculation for PS-2390A & B, Condensate Tank Low Level Transfer", Rev. 2, 10/7/2009 (attached) (27 Pages)
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