ML052210431

Supplement to License Amendment Request (LBDCR 05-MP2-001) Trisodium Phosphate Technical Specification

ML052210431
Person / Time
Site:	Millstone
Issue date:	08/04/2005
From:	Grecheck E Dominion Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
05-049A
Download: ML052210431 (7)

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Dominion Nuclear Connecticut, Inc.

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\Y.ltcli;,rd, CI06385 August 4, 2005 U.S. Nuclear Regulatory Commission Serial No. 05-049A Attention: Document Control Desk NLOS/PRW RO One White Flint North Docket No. 50-336 11555 Rockville Pike License No. DPR-65 Rockville, Maryland 20852-2738 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2 SUPPLEMENT TO LICENSE AMENDMENT REQUEST (LBDCR 05-MP2-001)

TRlSODlUM PHOSPHATE TECHNICAL SPECIFICATION In a letter dated February 25, 2005, Dominion Nuclear Connecticut, Inc. (DNC) provided a request to amend the Millstone Power Station Unit 2 (MPS2) operating license to modify the technical specification surveillance requirement for trisodium phosphate (TSP) to remove the granularity term and chemical detail.

In a facsimile dated July 7, 2005, the NRC provided a draft request for additional information (RAI) asking DNC to clarify certain items in DNCs February 25, 2005 submittal. In a phone conversation held on July 12, 2005, Dominion agreed to provide a response to the draft RAI by August 5, 2005. The attachment to this letter provides the supplemental information requested.

The additional information provided in this letter does not affect the conclusions of the safety summary and significant hazards considerations discussion in the DNC letter dated February 25, 2005.

Should you have any questions regarding this submittal, please contact Mr. Paul R. Willoughby at (804) 273-3572.

Very truly yours, Eugene S. Grecheck Vice President - Nuclear Support Services Attachments: (1)

Commitments made in this letter: None

Serial No. 05-049A Docket No. 50-336 Supplement to License Amendment Request Trisodium Phosphate Technical Specification Page 2 of 3 cc: U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-141 5 Mr. V. Nerses Senior Project Manager - Millstone Unit 2 U.S. Nuclear Regulatory Commission One White Flint North 1 1555 Rockville Pike Mail Stop 8C2 Rockville, MD 20852-2738 Mr. S. M. Schneider NRC Senior Resident Inspector Millstone Power Station Director Bureau of Air Management Monitoring and Radiation Division Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127

Serial No. 05-049A Docket No. 50-336 Supplement to License Amendment Request Trisodium Phosphate Technical Specification Page 3 of 3 COMMONWEALTH OF VIRGINIA )

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COUNTY OF HENRICO 1 The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Eugene S. Grecheck, who is Vice President - Nuclear Support Services of Dominion Nuclear Connecticut, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this 4% day of 4- , 2005.

My Commission Expires:

Y 0 Notary Public (SEAL)

Serial No. 05-049A Docket No. 50-336 ATTACHMENT LICENSE AMENDMENT REQUEST (LBDCR 05-MP2-0011 TRlSODlUM PHOSPHATE TECHNICAL SPECIFICATION SUPPLEMENTAL INFORMATION MILLSTONE POWER STATION UNIT 2 DOMINION NUCLEAR CONNECTICUT, INC.

Serial No. 05-049A Docket No. 50-336 Supplement to License Amendment Request Trisodium Phosphate Technical Specification Attachment Page 1 of 3 LICENSE IENT REQUEST (LBDCR 05-MP2-001)

TRlSODlUM PHOSPHATE TECHNICAL SPECIFICATION SUPPLEMENTAL INFORMATION By letter dated February 25, 2005, Dominion Nuclear Connecticut, Inc. (DNC) submitted a request to modify the Technical Specification surveillance requirement for trisodium phosphate (TSP). The NRC has developed the following question during its review of the DNC letter.

NRC Question In page 4 of the February 25, 2005 submittal, DNC stated: "Past testing on compacted TSP indicates that even if the TSP crystals become compressed and partially fused together] rapid dissolution is still assured. Please justify your statement and provide more specific information on how you arrived at your results.

DNC ResDonse Dominion Nuclear Connecticut, Inc. (DNC) affirms the statement regarding rapid dissolution of compressed trisodium phosphate (TSP) crystals based on the following :

1. Initial testing conducted by Combustion Engineering in the early 1970's.

2. Surveillance testing conducted at Millstone Power Station Unit 2 (MPS2) since March 1999.

Testina Conducted bv Combustion Enaineerinq As clarification to the information discussed with the NRC in the phone conversation of July 12, 2005, the temperatures used in CE's testing were 200°F and 185°F. During the phone call, DNC indicated the testing was done at 200°F and 85°F based on a table in the CE documents summarizing the test results.

However, a more detailed review of the documents indicates that the cited 85°F in the table is a typo, and that the testing was done at 185°F. In the introductory paragraph describing the testing, CE says a number of tests were performed to measure the rate of solution of TSP "near the boiling point of water." And, in the experimental method write-up, CE says, "Tests were performed by immersing the pellets in stagnant and flowing water at 185°F and 200°F."

To reiterate the information provided in the phone call, Combustion Engineering formed standard-size cylindrical TSP pellets from granulated trisodium phosphate. Pellets were formed by compression of the granulated TSP at

Serial No. 05-049A Docket No. 50-336 Supplement to License Amendment Request Trisodium Phosphate Technical Specification Attachment Page 2 of 3 pressures of 5000, 10,000 and 20,000 psia. The TSP pellets were then immersed in warm water as described above. The pellets were completely dissolved within approximately six minutes with no solution agitation, and within approximately two minutes with solution agitation.

DNC Surveillance Testinq To reiterate the information provided during the phone conversation of July 12, 2005, samples are taken from the surface of the TSP in the baskets and then placed in room temperature water without agitation for dissolution. DNC samples the surface of the TSP as this material is more likely to be adversely affected by containment conditions than the bulk of the TSP material beneath the surface layer. The surveillance time limit for dissolution is 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

In 1998, Millstone determined the required volume of TSP needed to be increased. Two of the five TSP baskets were replaced with larger baskets, and additional TSP was added to increase the TSP volume to the requisite value. A scribe mark on each basket indicates the fill level to meet the minimum allowable volume requirement. The basket fill is verified each refueling outage by Operations personnel. Should the level of TSP be below the required fill level indicated for the associated basket, more TSP is placed in the baskets along with the TSP already there. Even though the level of the TSP may decrease over time, the same mass of TSP remains in the baskets, but is compressed. Adding more TSP actually increases the mass of TSP available for neutralization of the coolant in the containment sump during accident conditions.

During the phone conversation of July 12, 2005, DNC indicated that it believed no TSP had been added to the baskets since 1998. However, a detailed review of the completed TSP level surveillances since September 1998 indicates that TSP has been added to one of the five baskets twice since 1998 (in April 2000, and again in April 2005),and once to one other basket (in April 2005). Both of the baskets that required additional TSP were the two larger baskets installed in 1998. These two baskets (5 x 5 x 4.5 deep) replaced two smaller baskets (5 x 5 x 1.5 deep) as noted previously. DNC believes the required TSP additions to these two baskets is the result of settling/compression of the additional TSP volume added in 1998. The three other TSP baskets (of the original 5 x 5 x 1.5 deep design) in containment have not had any material added to them since before 1998.

Serial No. 05-049A Docket No. 50-336 Supplement to License Amendment Request Trisodium Phosphate Technical Specification Attachment Page 3 of 3 Millstone has verified TSP buffering capability at MPS2 five times since increasing the required volume of TSP during the extended outage. The results of the surveillances are as follows:

0 March 19, 1999: 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 46 minutes for 0.6718 grams to dissolve in 75.6"F water without stirring May 1, 2000: lhour and 29 minutes for 0.6797 grams to dissolve in 79°F water without stirring 0 Feb., 19, 2002: 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 5 minutes for 0.6700 grams to dissolve in 72.7"F water without stirring Oct. 27, 2003: 20 minutes for 0.6514 grams to dissolve in 78.9"F water without stirring April 24, 2005: 51 minutes for 0.6690 grams to dissolve in 76.3"F water without stirring As evidenced by the above, there is a substantial variation in the recorded time for TSP dissolution during these surveillance tests. This is most likely due to the way the dissolution portion of the surveillance is conducted. Typically, the Chemistry technicians performing the surveillance place the TSP into the water, record the start time, and then perform other functions, intermittently checking the TSP to see when dissolution is complete. The technicians do not continuously monitor the TSP and thus may record a bounding time and not the exact time dissolution is complete. The compaction of the TSP sample may also play some role in the recorded dissolution time, but it is believed this is a minor impact compared to the lack of continuous monitoring of the solution.

The difference in dissolution times between the CE tests conducted with no solution agitation (-6 minutes) and the surveillances performed at MPS2 (220 minutes) is believed to be the result of the difference in solution temperatures.

The CE tests were conducted in hot water (185°F and 200°F solutions); whereas, the MPS2 surveillance is conducted in room temperature water (77 k 5°F). The Merck Index) indicates that TSP is soluble in 3.5 parts room-temperature water and 1 part boiling water.

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(') The Merck Index: An EncvcloDedia of Chemicals, Druas, and BioloaicalS, 10th Edition, by Martha Windholz, et. al., Merck and Company, Inc., 1983. TSP is monograph number 8503 (sodium phosphate, tribasic) on page 1240.