ML20206H288

Forwards S&W Thermal Effects on Precoat Matl for Spent Fuel Pool Filter/Demineralizers, Per Request for Addl Info Re Spent Fuel Pool Cooling Sys Max Temp Limit.All Components in Sys Able to Operate at 150 F Fluid Temp Tech Spec Limit

ML20206H288
Person / Time
Site:	Vermont Yankee
Issue date:	04/09/1987
From:	Capstick R VERMONT YANKEE NUCLEAR POWER CORP.
To:	Rooney V NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
Shared Package
ML20206H290	List: ML20206H288 ML20206H733
References
FVY-87-40, NUDOCS 8704150319
Download: ML20206H288 (5)

Text

_

NERMONT YANKEE' NUCLEAR POWER CORPORATION RD 5, Box 169. Ferry Road, Brattleboro, VT 05301 AEPLY TO.

y ENGINEERING OFFICE 1671 WORCESTER ROAD

• FRAMINGHAM, MASSACHUSETTS 01701

• TELEPHONE 617-872-4100 April 9, 1987 FVY 87-40 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Attention: Office of Nuclear Reactor Regulation Mr. Vernon L. Rooney BWR Project Directorate No. 2 Division of BWR Licensing

References:

(a) License No. DPR-28 (Docket No. 50-271)

(b) Letter, VYNPC to USNRC, FVY 86-34, " Proposed Technical Specification Change for Spent and New Fuel Storage,"

dated April 25, 1986

Subject:

Vermont Yankee Proposed Spent Fuel Pool Expansion - Response to Request for Additional Information Concerning the Spent Fuel Pool Cooling System Maximum Temperature Limit

Dear Sir:

Pursuant to your recent request for additional information in support of our spent fuel pool expt.nsion request (Reference (b)], we have provided as Enclosure 1 to this letter, documentation demonstrating the acceptability of the 1500F temperature limit for the Spent Fuel Pool Cooling System. In summary, all components in the system, including the demineralizer resin, have been documented as capable of nondegradable continuous operation at the current 1500F fluid temperature Technical Specification limit.

1 Additionally, we have provided as Enclosure 2 to this letter, the technical report, " Thermal Effects on Precoat Material for Spent Fuel Pool Filter /Demineralizers, Vermont Yankee Nuclear Power Station," which demonstrates acceptable resin performance at temperatures above 1500F.

Should you have any questions or require further information concerning this matter, please contact this office.

Very truly yours, P

o hg VERMONT YANKEE NUCLEA POWER CORPORATION PDR 2 obert W. Ca stick Licensing Engineer RWC/sj Enc 1_.s ,y

. - ~. ~ . - .

'*~ ~l

E-

.- )

ENCLOSURE I Evaluation of 150 0F Spent-Fuel. Pool-Temperature Technical. Specification Limit ~ Acceptability

SUMMARY

)

[ The Vermont Yankee Spent Fuel Pool Cooling System'(SFPCS) was reviewed.for '

acceptability of a 1500 F maximum temperature Technical Specification Limit in' Sections 3.12.H and.4.12.H. All components in the system, including the i domineralizer resin, were reviewed and determined to be capable of nondegradable continuous operation with 1500F_ fluid temperature.

Therefore, it is concluded that the existing. Technical Specification 1500 F limit is. appropriate and acceptable for the Vermont Yankee Spenh Fuel Pool

' Cooling. System.

DISCUSSION 4 ,

Vermont' Yankee Technical Specification Paragraphs 3.12.H and 4.12.H require the spent fuel pool water temperature to be maintained below 1500F. The NRC Standard Review Plan (SRP) 9.1.3, Paragraph III.1.d states a maximum pool

.waturgtemperature of 140 0F. Accordingly, Vermont Yankee evaluated the spent fuel pool maximum temperature limit in response to NRC's request ~by reviewing the design of all basic components in the Spent Fuel. Pool. Cooling System.

Each of the basic components were reviewed against a 1500F fluid temperature in order to determine if the present Technical Specification max) mum fluid temperature limit of 1500 F can be maintained or should be reduced to 1400F, as stated in SRP 9.1.3.

The Spent Fuel Pool Cooling System consists of six basic components that are in direct contact with system fluid temperatures.

[ o Pumps

o Heat Exchangers

o Demineralizer Vessels

, o Demineralizer Resin

! o Piping o Valves L The individual component reviews are as follows:

SFPC Pumps These pumps are Peerless Model 4x3x8-1/2 "E" with a-design temperature of 1500F (Reference 3). This model pump has no unique or special material or-design features that would preclude its continuous operation above its specified design temperature. In addition, these pumps are capable of'being recertified to a higher design temperature.

l i

g ._.. 9 SFPCS H mt-Exchang+r*

' These heat exchangers were manufactured _by Foster Wheeler (Reference 2) using

. a design. temperature of 150 0F. :These heat-exchangers'have no unique'or

~

special material or design features _that would preclude continuous operation 1 ,

3

. _ above'their specified design temperature of 150 F, 0 These heat exchangers are also capable of being recertified to'a higher design temperature.

. ' Demineralizer Vessel -

The SFPCS demineralizer vessels have a design temperature of'2000F

~

(Reference 4). 4 4

Domineralizer Resin The POWDEX Fuel Pool Filter /Demineralizer System consisting of vessels (above)'

I and Graver ECODEX 205H resin is designed.to treat a maximum" flow of 1 450 gpm/ unit at a maximum pressure.of 150 psi and a maximum temperature of 2000 F for the reduction of. ionic, particulate materials and dissolved-solids.

from an in-plant water system.

POWDEX is a process designed to remove or substantially reduce dissolved. salts and suspended matter, together with colloidal particles and complexes lpresent i in the fuel pool water. Because of the ion exchange kinetics exhibited by the high reaction rates of finely ground; resin and the filtration which taken i

place throughout a depth of synergistic resin layer (rather than purely-surface filtration), POWDEX process possesses the inherent capacity-to efficiently _ remove or substantially reduce iron, copper, metallic oxides suus complexes, organics, salts, including chlorides, all.regardless of form, to

. extremely low levels.

The ECODEX 205H resin has a recommended maximum-operating temperature of.

1400 F.to coincide with its optimum point _of efficiency. An evaluation.

F (Reference 5) was performed in order to confirm its acceptability at higher

, temperatures. The evaluation concludes that this resin will perform-acceptably at higher temperatures. . Performance efficiency decreases as temperature increases, but this can be offset by more frequent resin l changes.

1 At an influent temperature of 150 0F the resin efficiency is reduced by approximately two percent. Considering normal run. times of 20 to 30 days, continuous operation at 1500F would result in a need to change resin

approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> earlier to maintain the same effluent-chemistry.

Reference No. 5 concludes this resin is capable of continuous acceptable operation above 150 0F.

Piping f The piping has a design temperature of 1750 F (Reference 6).

i

}

r i

-r'- - - - - , emu 4 v- =- -w .e r ve- -tw> . . - - .n w w+ee- w -r---=wr--e--&--.= i e-r r -'

w ' ' . *

• 4 Velv*1 The valves used in the SFPCS were purchased'under various specifications.

according.to valve type. All the valves ~(mostly diaphram valves) supplied by the POWDEX System (Reference 4) manufacturer (Graver) were specified to have a design temperature of 200 0F. All the other valves in the system were specified to have a design temperature of at least 1750F. No valves were found that had; unique or special material or design features that could be .

construed as low temperature service valves, ~ where temperatures below 2000F raay - degrade them.

CONCLUSION It is concluded that'the demineralizer resin appears to be the limiting component in the SFPCS, considering its recommended maximum _ optimum operating temperature of 140 0F. However, this does not prove to be the .11miting component since the resin has been analyzed as capable of continuous operation at temperatures well above 150 0F.

Based on design temperature alone, the limiting components in the SFPCS are the pumps and heat exchangers. Both the SFPC pumps and heat exchangers have a design temperature of 1500F. However, because they have no unique or special material or design features, they would not be degraded by higher temperatures in the 1500F to 2000F range.

Therefore, a maximum pool bulk temperature, and a maximum temperature at the inlet to the pumps and heat exchangers, of 1500 F-is within the design of all components of the SFPCS.

i l

'l1

o REFERENCES-

1. Standard Review Plan (SRP) 9.1.3, Spent Fuel Pool Cooling and Cleanup System (NUREG - 0800)

2. Foster Wheeler Corporation Drawing 58-845-3-5,. Revision A, 500 Square Foot Fuel Pool Cooling Heat Exchanger, EBASCO File No. 5920-2639=

3. EBASCO Specification, Purchase Order No. NY-706171, Miscellaneous Pumps, Microfilm Location Roll No. 34, Frame 2317

4. Ceneral Electric Specification, Specification No. 21Al235AE, Revision 3, Fuel Pool Filter /Demineralizer Systems

5. Stone and Webster Engineering Corporation Report, Prepared by L. J. MacKoul, Thermal Effects on Precoat Material for Spent Fuel Pool Filter /Demineralizers Vermont Yankee Power Station, March 1987 (Report enclosed)

6. P&ID Drawing G-191173, Flow Diagram Fuel' Pool Cooling and Cleanup System 1

f 4

_ _ _ _ . , , _ , m.