ML20090G511

Forwards DOE Responses to NRC SER W/Recommendations on West Valley,Ny Supernatant Treatment Sys

ML20090G511
Person / Time
Site:	West Valley Demonstration Project
Issue date:	03/04/1992
From:	Rowland T ENERGY, DEPT. OF
To:	Gary Comfort NRC
References
REF-PROJ-M-32 NUDOCS 9203120306
Download: ML20090G511 (8)

Text

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Depart:11ent of _ Energy -

Idaho Operations Offico g3pf

3, ,\/d , j West Valley Project Office

'% 6* P.O. Box 191 West Valley, NY 14171 ,

1 March 4,1992  ;

i Mr. G. C. Comfort i l

U.S. Nuclear Regulatory C':t asion Headquarters Washington, DC 20555

SUBJECT:

West Valley Demonstration Project (WVDP) Responses to NRC Recommendations Made in the Supernatant Treatment System Safety Evaluation Report

Dear Mr. Comfort:

Enclosed for your information are responses to the recommend-ations made in the NRC's Safety Evaluation Report of the WVDP's Supernatant Treatment System.

If you have any comments or questions, please contact R. B. Provencher of my staff at FTS 4"3-4101.

Sincerol ,,

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/.' R'o 1 d, Director West Valley Project Office

Enclosure:

Responses cc: J. L. Lyle, DOE-ID (w/o enc)

T. W. McIntosh, DOE-HQ (w/o enc)

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RESPONSES TO NRC SER ON STS SAR (REV. 6)

No. NRC SER Suggestion WVNS' Response 1 Pg. 5, paragraph 5, sentence 4 - Technical Requirement (TR)-IRTS-

"The NRC expects DOE to 12 requires measurement, accurately measure, record, and tracking and recording of the Pu report the Pu levels in the wash concentration in the STS solution and STS treated water, solution prior to transfer to and to ascertain when its removal the LWTS. TR-IRTS-ll requires becomws necessary to prevent measurement, tracking and transport to the LWTS." recording of the LWTS feed prior to the evaporator.

Pg. 23, paragraph 5, sentence 4 -

"The NRC expects DOE to accurately measure, rccord, and report plutonium levels in the wash solution and STS treated water, and to ascertain when its removal becomes necessary to prevent transport to the LWTS."

2 Pg. 14, paragraph 3, sentence 2 - Table D.6.5-1 indicates that "Since any leakage of the sludge individual pump enclosures along the shaft will result in cor.tain radiation detection contamination of the shaft and instrumentation. The radiation inner walls of the pump (sludge detectors monitor the pump mobillracion pump), the manner column for radioactive and frequoney of the monitoring contamination. High exposure-process should be clearly rate activates the external pump described." enclosure visual alarm and horn.

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.4 No. NRC SER'Suqqestion~- WVNS' Response

< 3 Pg. 14, paragraph 5, sentence 4 - Internal corrosion-of tank 8D-1

... however, the specific type is assessed by t.5e use of two '

of coupons and the degree to corrosion coupon racks--(inside which corrosion coupons are the tank) which contain various.

streses3 are important and should ' types of coupons. One of these

[ be reported along with racks resta-on the tank floor or  !

I qualitative results." on the zeolite covering the tank.

floor. Coupons on this rack Pg. 14, paragraph 5, sentence 5 - indicate corrosion activity in

. . . additional ef forts to the liquid /seolite region of the mor.itor the potential for tank. The other coupon rack corrosion are justified to assure floats at the liquid-to-vapor-the safety of the tanks." interf ace and coupons are-located on the rack to provide Pg. 15, paragraph 1, sentence 2 - corrosion data for the liquid, "Similar-quantitative results the vapor and the= liquid-vapor should be given to indicate that interface regions. The coupons pitting will not be a problem." listad below provide data.that are used to assess general F0 15, paragraph 1, sentence 3 - corrosion (wall thinning),

" Additional efforts are justified- concentrated pitting, stress to monitor the potential for the corrosion cracking and crevice three major types of corrosion corrosion.-

(wall thinning, concentrated pitting, and streso corrosion cracking) on the carbon stool Lxation tank material.. Type coupon vap.119. v/L 2eolite totat Plain Coupon 2 4 1 4 11 Pg. 23, paragraph 6, sentence 2 - crevice cagon 2 4 1 4 J11 "However, activities.to monitor U bwd -

2 3 0 3 8 the three types of corrosion are Double U bend 0 2- 0 2 4 encouraged.= CT spcInn 2 2 0 4- 8 Archive Coupon 0 0 0 0 2 corrosion data were obtained from coupon examination after nine months.of exposure inside

. tank 8D-1 from December 1988 to September 1989. Results indicate.that the vapor phase was most corrosive:with an-average general corrosion rate of 0.78 mils /yr and a maximum of' l.2 ils/yr. General' corrosion in " e zeolite and liquid reg ,ns averaged 0.62 mils /yr and 0.07 mils /yr, respectively.

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'. 4 No. NRC SER Suggestion WVNS' Response 3 Significant pitting was observed cont on the coupons in the zeolite region. However, the depth of the pitting could not be accurately measured.

A pitting corrosion inhibitor has bean subsequently added to the tank. Action will be taken to quantify pitting depths during future coupon .

examination. l Stress corrosion cracking and cravice corrosion were not detected by coupon examination.

Stress corrosion cracking in tank 8D-1 is assessed by examination of U-bend corrosion coupons in the various regions of the tank. U-bend coupons are designed and fabricated to ASTM-G30 requirements.

Pitting corrosion is being measured by corrosion coupons in tank 8D-1. The only significant pitting corrosion is present in the zeolite region of the tank.

Examination of coupons submerged in the teolite at the bottom of the tank indicate that a localized pitting corrosion of up to a maximum of 4.06 mils /yr may have been present prior to addition of the pitting corrosion inhibitor (sodium nitrate) to the tank. The rate of pitting will be assesead in mid-1992 when the. coupons will be removed again for examination.

Corrosion data from tank 8D-2 have been unavailable since the NFS coupons were removed from the tank in 1982. These coupons indicated a general corrosion I rate of.0.53 mils /yr for the liquid region.

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No. NRC SER Suogestion WVNS' Response 3 In October 1991, a series of cent corrosion probes were installed into tank 8D-2 to measure actual corrosion rates. These probes are advantageous in that the time required for frequent corrosion coupon removal, cleaning, examination-and reinstallation is greatly reduced. The probes provide on-line indication of general tank corrosion in all three regions:

sludge, liquid and vapor.

During the limited period of time these probes have been operating, general corrosion rate indications have been:

3.2 mils /yr in the sludge region 0.3 mils /yr in the liquid region 1.9 mils /yr in the vapor-region n addition, 0.2 mils /yr pitting corrosion in the liquid region is indicated by the pitting corrosion probe. -The WVDP is currently assessing the need and feasibility of installing corrosion coupons into tank SD-2, in addition to the existing corrosion probes.

Stress corrosion cracking in tank 8D-2 is not currently measured, but laboratory corrosion tests at Battelle-PNL are underway to determine if this type of corrosion is significant.

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_gy No. NRC SER Suggestion WVNS' Response 3 An on-line probe was installed, cont in October of 1991, is the liquid region of tLnk 87-2 to attempt to monitor tira p'.tting corrosion inside this tank.

Initial data from this probe indicates a pitting corrosion rate of 0.2 mils /yr, although tne measurement probe and signal conditioning syntam are still in the developmental stage.

Preparations are being made for laboratory tests at Battelle-PNL to evaluate the magnitude of corrosion on the tank exteriors due to the infiltration of surface and ground water. This data will be combined with internal corrosion data to predict total tank wall corre* on.

4 Pg. 17, pare. graph 4, sentence 3 - A lightning scrike can be an "The SAR whould demonstrate some initiator for a number of consideration of the phenomenon acenarios which were analyzed of lightning strikes, because of (e.g., fires, loss of power, their common occurrence and the structural damage). Therefore, potential resultant damage." the consequences of a lightning strike are enveloped by the Pg. 17, par 6 graph 5, sentence 4 - analyses presented in Rev. 6 of l "Thd SAR should include a the SAR.

rationale for not considering the

! Phenomecon of lightning, similar to the rationale for not 4

considering the effect of a l tornado on the control room, d'.. cussed elsewhere in the SAR."

Pg. 24, paragraph 3, sentence 1 -

"The review of accident conditions that are potentially threatening to STS equipment and ope ation suggests that lightning I strikes also be-considered since they are a credible natural phenomenon."

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4 No. NRC SER Succestion WVNS' Response-5 Pg. 18, paragraph 2, sentence 4 - The effect of a tornado on the "The SAR should include mention STS and SMWS structures is of the sludge mobilization pump censidered in Table D.9.3-1.

access in its discussion on Tnis includes the effect of a tornado'aissiles, along with a DBT on the sludge mobilization rationale similar to that pumps. The pump enclosures are i provided elsewhere in the SAR for only weather structures and no 1 not considering the effect of a credit has been taken for these tornado on the control room." structures in the analyses. The entry for the pump column Pg. 18, paragraph 3, sentence 7 - barrier is included for "The SAR should more clearly completeness.

indicate that failure (of the i pump column barrier) is not expected by eliminating the entry in Table D.9.3-1."

Pg. 24, paragraph 3, wentence 2 -

"The effect of a tornado missile on the SMWS pump access and enclosure is also suggested for consideration since this la a possible event."

6 Pg. 21, paragraph 6, sentence 10 Section D.4.1.1.6 indicates that "The " assumed" value in Section the force of 468 pounds is B.2.2 on Page B-8 of the Appendix within the allowable stress for of Reference 12 should be the bottom gridwork. Therefore, consistent with the 468-pound interaction between the pump and value to avoid the implication the bottom gridwork does not that the pump shaft will deflect affect tank SD-2 integrity.

and impact with fine at the Reference 12, Section B.3.4, bottom of the tank." page B-ll, discusses the jet Lmpingement loads on the bottom Ref. 12. Gates, William E., gridwork.

" Report: 8D-2 Sludge Mobilization Wash System Confinement Barrier Integrity Review," West Valley Demonstration Project Subcontract No. 19-29929-C-MS, Task 10 for West Valley Nuclear Services Company, Inc. l DMS1052: SEA-176 6

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No. KRC SER Succestion WVNS' Response 7 Pg. 22, paragraph 5, sentence 2 - The WVDP has a formalized ALARA "The WVDP ALARA program is program which documents our sufficient, however, DOE may commitment to radiation consider adding an operaticnal protection of workers and the trend analysis to their ALARA public and is in compliance with program." DOE Orders. The program incorporates measures to track Pg. 24, paragraph 4, sentence 1 - and, if necessary, to reduce

" Finally, the review recommends radiation exposures. The WVDP that operational trend analysis ALARA program is equivalent t'>

be added to the WVDP's ALARA the trend analysis. ALARh program,..." trends are tracked, analyzed, and reported on a monthly basis.

All unexpected levels of exposure are investigated. In addition, all jobs which have an anticipated cumulative dose greater than 100 mrem have a formal ALARA review performed to investigate methods of dose reduction. Following the job, analyses are performed to determine if lessons learned can be incorporated into future work activities.

8 Pg. 23, first sentence " Values Comment taken under given in Table D.8.6-1 reflect consideration for possible the effluent release during the addition to a future revision of total period of operations (18 the SAR.

months), which DOE may consider indicating in the Table."

9 Pg. 25, paragraph 6, sentence 2 - NRC decontamination and "This plan (WVDP Long-term decommissioning criteria will be Radioactive Waste Management evaluated by the WVDP and Plan) should be revised, as incorporated into the Long-term necessary, as new decontamination Radioactive Waste Management and decommissioning criteria are Plan ar appropriate.

established by the NRC."

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