ML061210067
| ML061210067 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 06/22/2006 |
| From: | Padovan L Plant Licensing Branch III-2 |
| To: | Harden P Nuclear Management Co |
| padovan L, NRR/ADRO/DORL, 415-1423 | |
| References | |
| TAC MD0537 | |
| Download: ML061210067 (7) | |
Text
June 22, 2006 Mr. Paul A. Harden Site Vice President Nuclear Management Company, LLC Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530
SUBJECT:
PALISADES PLANT REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE LICENSE AMENDMENT REQUEST TO REMOVE TRI-SODIUM PHOSPHATE FROM THE PALISADES CONTAINMENT (TAC NO. MD0537)
Dear Mr. Harden:
Your letter of March 20, 2006, requested a license amendment to remove tri-sodium phosphate from the Palisades containment. We are reviewing your request, and find that we need additional information as shown in the enclosed request for additional information (RAI). I discussed this RAI with Ms. Amy Hazelhoff of your organization on June 9, 2006, and she agreed to respond by July 8, 2006. Please contact me at (301) 415-1423 if you have questions.
Sincerely,
/RA/
L. Mark Padovan, Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255
Enclosure:
RAI cc w/encl: See next page
June 22, 2006 Mr. Paul A. Harden Site Vice President Nuclear Management Company, LLC Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530
SUBJECT:
PALISADES PLANT REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE LICENSE AMENDMENT REQUEST TO REMOVE TRI-SODIUM PHOSPHATE FROM THE PALISADES CONTAINMENT (TAC NO. MD0537)
Dear Mr. Harden:
Your letter of March 20, 2006, requested a license amendment to remove tri-sodium phosphate from the Palisades containment. We are reviewing your request, and find that we need additional information as shown in the enclosed request for additional information (RAI). I discussed this RAI with Ms. Amy Hazelhoff of your organization on June 9, 2006, and she agreed to respond by July 8, 2006. Please contact me at (301) 415-1423 if you have questions.
Sincerely,
/RA/
L. Mark Padovan, Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255
Enclosure:
RAI cc w/encl: See next page DISTRIBUTION:
PUBLIC RidsNrrPMMPadovan RidsNrrLATHarris RidsNrrDorlLpl3-1 RidsNrrDorlDpr RidsOgsRp RidsAcrsAcnwMailCenter CLipa, Rgn-III MHart LBrown LPL3-1 R/F YDiaz-Castillo RArchitzel RTorres PKlein MYoder TKoshy MKotzalas MScott TBloomer ADAMS Accession Number: ML061210067 OFFICE NRR/LPL3-1/PM NRR/LPL3-1/LA NRR/LPL3-1/BC NAME LPadovan THarris LRaghavan DATE 06/21/06 06/22/06 06/22/06 OFFICIAL RECORD COPY
Palisades Plant cc:
Robert A. Fenech, Senior Vice President Nuclear, Fossil, and Hydro Operations Consumers Energy Company 1945 Parnall Rd.
Jackson, MI 49201 Arunas T. Udrys, Esquire Consumers Energy Company 1 Energy Plaza Jackson, MI 49201 Regional Administrator, Region III U.S. Nuclear Regulatory Commission Suite 210 2443 Warrenville Road Lisle, IL 60532-4351 Supervisor Covert Township P. O. Box 35 Covert, MI 49043 Office of the Governor P. O. Box 30013 Lansing, MI 48909 U.S. Nuclear Regulatory Commission Resident Inspector's Office Palisades Plant 27782 Blue Star Memorial Highway Covert, MI 49043 Michigan Department of Environmental Quality Waste and Hazardous Materials Division Hazardous Waste and Radiological Protection Section Nuclear Facilities Unit Constitution Hall, Lower-Level North 525 West Allegan Street P.O. Box 30241 Lansing, MI 48909-7741 Michigan Department of Attorney General Special Litigation Division 525 West Ottawa St.
Sixth Floor, G. Mennen Williams Building Lansing, MI 48913 Michael B. Sellman President and Chief Executive Officer Nuclear Management Company, LLC 700 First Street Hudson, MI 54016 Jonathan Rogoff, Esquire Vice President, Counsel & Secretary Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Douglas E. Cooper Senior Vice President - Group Operations Palisades Nuclear Plant Nuclear Management Company, LLC 27780 Blue Star Memorial Highway Covert, MI 49043 Stephen T. Wawro, Director of Nuclear Assets Consumers Energy Company Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043 Laurie A. Lahti, Manager Regulatory Affairs Nuclear Management Company, LLC Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043
REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE REMOVAL OF TRI-SODIUM PHOSPHATE FROM CONTAINMENT PALISADES NUCLEAR PLANT (PNP)
DOCKET NO. 50-255 Part 1.
- 1. In Enclosure 1 of Nuclear Management Companys (NMCs) March 20, 2006, license amendment request regarding removal of tri-sodium phosphate from the Palisades containment, NMC stated that the current licensing basis at PNP includes atmospheric dispersion factors (/Q values) that are based upon site-specific, wind-tunnel modeling.
When, and by what mechanism, did this methodology become part of the Palisades licensing basis? Did the Nuclear Regulatory Commission approve this methodology for Palisades?
- 2. NMC further stated that Palisades has committed to submit a methodology change to a full-scope implementation of the alternative source term (AST) methodology in July 2006, which will establish a conforming radiological design basis for control room habitability and offsite doses at Palisades. Implementation of the full-scope AST methodology is currently expected to occur upon start-up from the fall 2007 refueling outage. Does this commitment specifically address if there will be a change in the methodology to be used to calculate X/Q values?
- 3. Page 10 of Enclosure 4 states that the exclusion area boundary and low population zone
/Q values used in the dose assessment for this license amendment request are those in the Palisades Final Safety Analysis Report. Were these /Q values previously reviewed and approved by the U.S. Nuclear Regulatory Commission staff as part of a prior license amendment request? If so, please provide an appropriate reference citation (e.g., safety evaluation report).
- 4. The loss of coolant accident radiological consequences analysis takes credit for wall deposition of elemental iodine as discussed in NUREG-0800, Standard Review Plan (SRP), Section 6.5.2, Containment Spray as a Fission Product Cleanup System, Revision 2. The elemental iodine wall deposition removal coefficient calculated by the SRP 6.5.2 method is based on a mass transfer coefficient for the conditions in the containment when sprays are operating. Changes to containment spray operation do not appear to be proposed in this amendment request. Are changes being proposed to post-accident containment spray operation?
Part 2.
- 1. In the event of a loss-of-coolant accident (LOCA) with recirculation, sodium hydroxide (NaOH) will be injected via the containment spray system within 7 days to control the containment pool pH. Provide an overview of the injection method, including NaOH spray duration, pH of the spray, and the range of containment pool pH once all NaOH has been injected. Discuss any assumptions.
- 2. Have any tests been conducted to evaluate potential interactions (i.e., chemical effects) between containment materials and a post-LOCA containment pool that does not contain a chemical to buffer pH? If so, please provide the results. If not, please discuss if there are any plans to investigate potential chemical effects in containments that do not have a buffering agent.
- 3. In relation to calculating release of the elemental iodine from the Safety Injection Refueling Water Tank (SIRWT), on page 5 of Enclosure 4 NMC said... appropriately justified airborne fractions for SIRWT leakage addresses the impact of TSP removal on iodine airborne fraction of leak sump water. Page 6 of Enclosure 4 provides the value of SIRWT iodine-volatile fraction of 0.453, and the corresponding maximum fraction of airborne elemental iodine of 0.0456. These values were determined in Nuclear Management Companys (NMCs) analysis included in Attachment 1 to Enclosure 4(?). Since the analysis is difficult to follow without having more details, please provide the following information:
Is the current analysis performed using one iodine concentration (e.g., maximum) in the SIRWT, or does it consider time-dependant values for different amounts of iodine leaked from the containment sump?
Justify using a concentration of 6.72E-05 g-atom/L of iodine in the SIRWT liquid. Since this value comes from Reference 11 in Attachment 1, why does it apply to the current analysis?
In your analysis, the pH used to determine the fraction of volatile iodine is 4.5, and it does not change with the in-leaking containment sump water. Justify this assumption.
In the analysis provided in Attachment 1 to Enclosure 4, please clarify the meaning of the numbers under the heading SIRWT Iodine Volatile Fraction.
Part 3.
NMCs letter of March 20, 2006, contained the following three new commitments:
- 1. NMC will implement a potassium iodide (KI) program for control room personnel at PNP upon approval of the license amendment request. The KI program will be implemented per the guidance provided in Nuclear Energy Institute 99-03, Control Room Habitability Assessment Guidance,....
- 2. NMC will inject sodium hydroxide as an alternate buffer within seven days post-LOCA with recirculation at PNP.
- 3. NMC will submit a license amendment request to implement an alternate buffer program after the Westinghouse Owners Group (WOG) Alternate Buffer Project is concluded.
The following additional information is needed to complete our review:
- 1. This item pertains to the timeliness of the proposed interim measure for addition of NaOH to control pH within 7 days following a LOCA.
The analysis of risk in the application appears flawed in that it solely addresses an unquantified avoidance of an increase in core damage frequency caused by postulated chemical effects blockage of the recirculation flow path. Recent NRC testing indicates a potential for incremental increase in blockage due to potential calcium silicate insulation and TSP chemical effects (above a debris contribution alone, which is considered the more likely cause of blockage). However, removal of the pH control, following both postulated and hypothetical accidents, increases the consequences of the entire set of such accidents when considering iodine reevolution from the containment pool. For design-basis accidents, NMC assessed that, considering this increase coincident with certain revised assumptions, the calculated doses remained within regulatory limits. Although this aspect is being reviewed by the staff, there remains, nonetheless, an unquantified increase in consequence associated with removal of any buffer which could offset any decreased risk achieved by removing the chemical effect blockage. Without a quantifiable evacuation of these offsetting risks, NMCs statement that there is a net increase in plant safety appears unfounded.
Regarding the impact of TSP removal on radiological consequences, NMC stated that in the event of a large-break LOCA with significant fuel damage, fission products released will likely control pH. The staff notes that the purpose of the proposed amendment is to avoid such fuel damage following an accident. Nonetheless, it would seem prudent to have pH control available in the event of significant core damage, versus relying on fission products to control pH. Also, NMC assumes that an additional source of conservatism is the dissolution of calcium silicate insulation following a LOCA. However, there is no assurance that any significant quantity of calcium silicate insulation will be dislodged and dissolved following a LOCA, nor will any be necessarily present for other hypothetical accidents, therefore considering its effects appears to be non-conservative.
Based on the above, the staff considers it prudent to have a readily-available (in hours upon detection of significant core damage, versus the 7 days proposed in the amendment) method to control pH. Additionally, the staff should review the method and system aspects as a part of the amendment review and approval, versus the current proposal to accomplish this task in the 60-days following approval of the amendment.
Please either address the points made by the staff in the above paragraphs, or describe how you will achieve buffer addition in a more timely manner than the proposed 7-days to mitigate iodine re-evolution from the sump pool.
- 2. Provide the methods and procedural plans to inject NaOH into the containment spray system. Include aspects of the operation of containment spray system to achieve NaOH addition to the sump pool.
- 3. Describe the specifications of the buffer to be used, how it will be stored on site, and its availability for use.
- 4. Provide calculations of the amount of NaOH to be added to complete the neutralization of the borated water added to the sump pool.
- 5. Describe testing and maintenance planned for the NaOH-injection capability.
- 6. NMC stated that it would submit a license amendment request to implement an alternate buffer after the WOG Alternate Buffer Project is concluded. This project may not provide definitive guidance for selection of an alternate buffer. Describe your plans and schedule to implement an alternate buffer.