ML20135G169

Forwards Request for Addl Info Re Spent Fuel Storage Capacity Expansion,To Complete Review of 850724 Request to Modify Tech Specs.Info Requested within 15 Days of Ltr Receipt

ML20135G169
Person / Time
Site:	Millstone
Issue date:	09/05/1985
From:	Butcher E Office of Nuclear Reactor Regulation
To:	Opeka J NORTHEAST NUCLEAR ENERGY CO.
References
TAC-59294, NUDOCS 8509180235
Download: ML20135G169 (9)

Text

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September 5, 1985 Docket No. 50-336 Mr. John F. Opeka, Senior Vice President Nuclear Engineering and Operations Northeast Nuclear Energy Company P. O. Box 270 Hartford, Connecticut 06141-0270

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION ON SPENT FUEL STORAGE CAPACITY EXPANSION FOR MILLSTONE UNIT 2 To complete our review of your request dated July 24, 1985 to modify your Technical Specification concerning the spent fuel storage capacity at Millstone Unit 2, we will need responses to the questions in the enclosure.

We request that you provide this infonnation within 15 days of your receipt of this letter. Questions from the Structural and Geotechnical Engineering Branch are still anticipated.

The information requested in this letter affects fewer than 10 respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely,

/S/

Edward J. Butcher, Acting Chief Operating Reactors Branch No. 3 Division of Licensing

Enclosure:

As stated cc w/ enclosure:

See next page Distribution:

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I' 1 o Mr. John F. Opeka Millstone Nuclear Power Station Northeast Nuclear Energy Company Unit No. 2 i CC: e Gerald Garfield, Esq. Mr. Wayne D. Romberg '

Day, Berry & Howard Superintendent Counselors at Law Millstone Nuclear Power Station City Place P. O. Box 128 Hartford, Connecticut 06103-3499 Waterford, Connecticut 06385 j Regional Administrator, Region I Mr. Edward J. Mroczka U.S. Nuclear Regulatory Commission Vice President, Nuclear Operations Office of Executive Director for Northeast Nuclear Energy Company Operations P. O. Box 270 .

631 Park Avenue Hartford, Connecticut 06141-0270 .

King of Prussia, Pennsylvania 19406 Mr. Charles Brinkman, Manager f' Washington Nuclear Operations

• C-E Power Systems Combustion Engineering, Inc.

, 7910 Woodmont Avenue Bethesda, Maryland 20814 ,

Mr. Lawrence Bettencourt, First Selectman Town of Waterford Hall of Records - 200 Boston Post Road ,

Waterford, Connecticut 06385 Northeast Utilities Service Company ATTN: Mr. Richard R. Laudenat, Manager '

Generation Facilities Licensing  ;

Post Office Box 270 l Hartford, Connecticut 06141-0270 Kevin McCarthy, Dimetor [

Radiation Control Unit Department of Environmental ,

Protection i State Office Building l Hartford, Connecticut 06106  ;

Mr. John Shedlosky Resident Inspector / Millstone  !

Box 811  ;

Niantic, Connecticut 06357 l Office of Policy & Management l ATTN: Under Secretary Energy l Division 80 Washington Street i Hartford, Connecticut 06106  ;

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REQUEST FOR ADDITIONAL INFORMATION MILLSTONE 2 SPENT FUEL STORAGE P0OL RAB #1. Provide the following infonnation:

1. Sources in the Spent Fuel Pool Water Provide a description of fission and corrosion product sources in the spent fuel pool (SFP) water from:(a) introduction of primary coolant into SFP water, (b) movement of fuel from the core into the pool, and (c) defective fuel stored in the pool. Include a listing of the radionuclides and their concentrations (expressed in pCi/mL) expected or measured during normal operations and refueling. The radionuclides of 137 interest should include 58Co, 60Co 134Cs, and Cs.

! 2. Airborne Radioactive Sources Provide a description of radioactive materials that may become airborne 3

as a result of failed fuel and evaporation (e.g., 85Kr and H, respectively). The radionuclide description should include calculated or j measured concentrations expected during normal operations and during l

refuelings.

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3. Miscellaneous Sources of Exposure Address the effects of more frequent replacement of demineralizer filters l on cumulative dose equivalent if this is a factor that results from the modification, j l

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4 RAB #2 In Section 5.2.2, " Radiological Considerations", provide the basis, models, input data, and assumptions for predicting the radiological impact of increasing the spent fuel pool capacity to 1112 assemblies.

RAB #3 Dose Rates from Fuel Assemblies, Control Rods, and Burnable Poison Rods

a. Provide a d'escription of the dose rate at the surface of the pool water from the fuel assemblies, control rods, burnable poison rods or any

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miscellaneous materials that may be stored in the pool. Additionally, provide the dose rate from individual fuel assemblies as they are being placed into the fuel racks. Information relevant to the depth of water shielding the fuel assemblies as they are being transferred into the racks should be specified. If the depth of water shielding over a fuel ,

assembly while it is being transferred to a spent fuel rack is less than -

10 feet, or the dose rate 3 feet above the spent fuel pool (SFP) water is greater than 5 mR/hr above ambient radiation levels, then submit a  ;

Technical Specification specifying the minimum depth of water shielding .

l over the fuel assembly as it is being transferred to the fuel rack and the measures that will be taken to assure that this minimum depth will not be degraded.

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b. Address the dose rate changes at the sides of the pool concrete shield walls, where occupied orcas are adjacent to these walls, as a result of the modification. Increa'sirg the capacity of the pool may cause spent [

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fuel assemblies to be relocated closer to the concrete walls of the pool, )

resulting in an increase of radiation levels in occupied areas. Please evaluate this potential problem.

RAB #4 Dose Rates from SFP Water Provide information on the dose rates at the surface of SFP water resulting from radioactivity in the water. Include: (1) dose rate levels in occupied areas and along the edges and center of the pool and on the fuel handling crane; (2) effects of c}ud buildup; and (3) based on refueling water activity, the dose rates before, during, and after refueling.

RA8 #5 4

I Dose Rates from Airborne Isotopes Based on the source terms, provide the dose rates from submersion and dose connitments from inhalation of airborne activity for exposure to the 85 3 concentrations of Kr and H.

RAB #6  !

Dose Assessment from Modification Procedures (1) Discuss the manner in which occupational exposure will be kept ALARA during the modification. Include the need for and the manner in which cleaning of the crud on SFP walls will be performed to reduce exposure i

rates in the SFP area.

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(2) Discuss vacuum cleaning of SFP floors if divers are used and the distribution of existing spent fuel stored in racks to allow maximum water shielding to reduce dose rates to divers.

(3) Describe plans for cleanup of the SFP water to minimize radioactive contamination and to ensure fuel pool clarity and underwater lighting acceptance criteria to help ensure good visibility.

(4) Discuss underwater radiation surveys that will be made before any diving operation. These surveys should be performed before or after any fuel movements or movements of any irradiated components stored in the pool. l (5) State your intent to equip each diver with a calibrated alarming dosimeter and personnel monitoring dosimeters, which should be checked periodically to ensure that prescribed dose limits are not being ,

exceeded. ,

(6) Discuss any preplanning of work by divers as required. .

(7) Discuss your provision for surveillance and monitoring of the spent fuel pool work area by Health Physics personnel during the modification. I T

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l CPB #1 You have not described or provided detailed results of the benchmark calculations for your methods which provide values of uncertainties and biases when calculating (1) fuel parameters including burnup, (2) your fuel poolconfigurations,(3)boronasusedinRegionI,(4)burnupeffectsasin Region II. Please describe these analyses and their applicability to your configurations and parameters, and present relevant results and conclusions on uncertainties. In particular, discuss the effects of axially non uniform burnups and reactivity parameters and their uncertainty (including extreme ranges which might be encountered). If some of this information has been presented (and approved) in other applications these may be referenced, but include a sumary, basis for applicability, and results for your configurations.

CPB #2 Your list of reactivity uncertainties contains no values for variation of B10 (via boroflex dimensions and content) and fuel parameters (enrichment, density,etc.). Please explain.

CPB #3 Is there any contained burnable poison in analyzed fuel?

CPB #4 Please discuss the pool temperature range studied for criticality, the temperature values used for conclusions on meeting pool criticality limits, and the demonstration that these constitute a maximum reactivity condition.

e CPB #5 You imply credit for the double contingency principle via pool boron for accidents in Region I as well as in Region II (although Region II is limiting) but you have no Technical Specifications for boron in Region I for assembly movement as you do in Region II. Please discuss and provide a Region I Specification unless otherwise justified. l CPB #6 It has been our policy in past reviews of spent fuel pools when credit for  !

burnup and multiple regions is involved that reactor unloading involve moving the fuel to be stored first to the fresh fuel region (in your case Region l I). Then when the reload is complete, a careful analysis and check of the burnup records is made. Only then is fuel moved into the burnup credit regions (Region 2). Please indicate if this procedure can and will be  !

i followed in your operations. Technical Specifications should reflect the  :

transfer and record keeping process. Please provide a discussion of the ,

procedures, limitations, record keeping and accountability measures taken ,

throughout the life of the facility that support the assumption that the inadvertent misplacement of fuel assemblies is not expected to occur.

CPB #7 ,

There is apparently a change, related to your Technical Specification l 5.6.1.a. for new fuel (dry) storage, (i.e., a limit on fuel enrichment).

However, there is no discussion of this area in your submittal. Please "

provide the analysis and justification for the limit. Please note that for  ;

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dry storage both full flooding, with a 0.95 criteria (including uncertainties),

and maximized low moderator density (e.g., from fire fighting), with a 0.98 multiplication criteria (with uncertainty), need to be considered unless approved provisions for preventing such conditions exist.

AEB #1 In accordance with guidelines of SRP 15.7.4, evaluate the radiological consequence of a cask handling accident that damages stored fuel. Include in the evaluation the assumption used and the basis for each assumption.

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