ML20236C891

Submits Final Rept on Status of Reactor Bldg Sump Beta Monitoring Sys.Rept Recaps 12-month Period of Evaluation. Proposes to Continue Using Batch Release Mode Currently in Place W/Sampling Each 24 H Until Release Completed

ML20236C891
Person / Time
Site:	Fort Saint Vrain
Issue date:	10/22/1987
From:	Robert Williams PUBLIC SERVICE CO. OF COLORADO
To:	Calvo J Office of Nuclear Reactor Regulation
References
P-87376, TAC-61580, NUDOCS 8710270386
Download: ML20236C891 (3)

Text

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19810Ci 27 A D I P.O. Box 840 Denver, CO 80201- 0840 R.O. WILLIAMS, JR.

October 22, 1987 vicE PRESIDENT NUCLEAR OPERATIONS Fort St. *!cain Unit No. 1 P-87376 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Attention: Mr. Jose A. Calvo Director, Project Directorate IV Docket No. 50-267

SUBJECT:

Final Report on the Reactor Building Sump In-Line Beta Monitoring System

REFERENCE:

1. PSC Letter, Gahm to Berkow dated 09/18/86 (P-86559)

2. PSC Letter, Gahm to l Berkow dated 12/22/86  !

(P-86655) ,

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3. PSC Letter, Williams to Berkow dated 03/22/87 (P-87113)

4. PSC Letter, Williams to Calvo dated 06/22/87 (P-87237)

5. PSC Letter, Williams to Calvo dated 09/22/87 (P-87333)

Dear Mr. Calvo; This is the final report on the status of the Reactor Building Sump Beta Monitoring System in accordance with Public Service Company of Colorado's agreement with you. This report recaps the 12 month period of testing and evaluation. A more complete recounting of events can be found in the references listed above.

8710270386 871022 PDR ADOCK 05000267 hg S PDR \

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., um l P-87376 October 22, 1987 The sequence of events that have led up to the purchase and testing of a Reactor Building Sump In-Line Beta Monitoring System began with i a Reactor Building Sump release on July 20, 1984, which exceeded the unknown radioactive Maximum Permissible Concentration for beta '

radiation. Subsequent analysis determined that the activity was due to Sulfur 35 and that no Maximum Permissible Concentrations were

{' exceeded. As a result of this release, Public Service Company of Colorado committed to perform releases from the Reactor Building Sump by batch method, whereby the sump contents are sampled and analyzed prior to commencing a release and at 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> intervals during the ,

release. Public Service Company of Colorado also committed to begin l investigation into the installation of in-line, beta-sensitive '

effluent monitors.

Subsequent evaluation of the July 20, 1984 release disclosed that the l source of the radioactivity in the Reactor Building Sump was the drain line from a compressor in the helium purification system. The subject drain was plugged and a survey of all drains in the Reactor Building was performed. The results of the survey indicated that all drains are correctly routed to either the Reactor Building Sump or the Liquid Waste Sump.

Investigation demonstrated that no commercially proven system was I available for on-line monitoring of the Reactor Building Sump for l beta radiation. It was decided to attempt to adapt equipment i designed for use in a biomedical laboratory application for use in l Reactor Building Sump releases. The system selected was RAMONA-LS l manufactured by Raytest and supplied by IN/US Service Corporation. '

From the outset, the suitability of an industrial use of this equipment was in question. The primary concern involves the quality of water in the Reactor Building Sump. The water in the Reactor Building Sump is composed of a variety of waste streams resulting from a number of leakage and cleaning operations. It is badly polluted with grease, oils, dirt and diverse particulate matter. As a result, it is diametrically different from the source solution for which the equipment was designed and does not allow the equipment to operate.

A concerted effort was made to both reduce the introduction of foreign material into the sump and to filter the water to achieve a suitable quality. Both attempts have proven to be fruitless. After extensive testing, we have concluded that this approach is ineffectual and should be abandoned in favor of some other alternative.

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. P-87376 :0ctober 22, 1987'

< ' We continue to.believe that the July 20, .1984 event was an. isolated case'that was. corrected.by plugging the drain.line from .the helium c . purification = compressor. Reactor: Building . Sump' analysis results h prior to and subsequent to the July 20, 1984 event have demonstrated

. compliance with. 10 CFR 20 limits as contained in the Fort St. Vrain

Technical Specifications. We propose to: continue using the batch

- release mode currently in_ place with sampling of the Reactor Building Sump prior to release and repeat sampling each. 24- hours .until the l 1,. release is completed. 4 L

Upon receiving your approval of this approach, we wil1~ submit a Technical Specification Change to reflect the above methodology _for performing releases from the ' Reactor Building Sump. We would be.

. pleased to meet with you and discuss this situation further, if you ,

. believe it necessary. l I

Should you have any questions, please contact Mr. M. H. Holmes.at:

(303)480-6960.

Sincerely, 20 Mi % s,Jr by $ 9 F 1 R. O. Williams, Jr.

Vice President, Nuclear Operations R0W:VHF/skd.

cc: Regional-Administrator, Region IV j ATTN: Mr. T. F. Westerman, Chief l Projects Section B l I

Mr. Robert Farrell Senior Resident Inspector .

Fort St. Vrain  !

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