ML20070T430

Operations Rept 43 for Natl Inst of Stds & Technology Reactor for 900101-1231

ML20070T430
Person / Time
Site:	National Bureau of Standards Reactor
Issue date:	12/31/1990
From:	Rowe J COMMERCE, DEPT. OF, NATIONAL INSTITUTE OF STANDARDS & TECHNOLOGY (FORMERL
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9104040181
Download: ML20070T430 (10)

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(301) 975-6210 FTS 879-6210 FAX (301) 921-9847 March 28, 1991 U. S.-Nuclear' Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Docket #50-184

, . Gentlemen:

!, Transmitted herewith is Operations Report No. 43 for the NDSR.

The report covers the period January 1, 1990 to December 31, 1990.

Ver truly y urs,

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.,. Michael Rowe Chief, Reactor Radiation Division Attachment cc: iP,roject Scientist U. S. Nuclear Regulatory Commission Region 1 475 A11andale Road King of Prussia, PA 19406 Project Manager Non-Power Reactor Directorate U. S. Nuclear Regulatory Commission Washington, DC 20555 9104040181 901231 PDR /. , !-

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N ATIONAL INSTITUTE OF STANDARDS AND TECliNOLOGY REACTOR (NBSR)

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Docket #50-184 Facility License No. TR 5 e

Operations Report-

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January 1,1990 December 31,1990 This report contains a summary of activities connected with the operations of the NBSR. It is submitted in fulfillment of section 7,8(3) of the NBSR Technical Specifica-tions and covers the period from January 1,1990 to December 31,1990,

' Section numbers in the report (such as 7,8(3)(a)) correspond to those used in the Tecnhnicel Specifications.

March 8,1991 '

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. $tichael Rowe Chief, Reactor Radiation Division I

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TABLE OF CONTENTS 7.8(3)(a) Summary of Plant Operations 7.8(3)(b) Unscheduled Shutdowns 7.8(3)(c) Tabulation of Major items of Plant Maintenance 7.8(3)(d) Tabulation of Major Changes in the Facility and Procedures, and the Test and Experiments, Carried Out Without Prior Approval by the NRC Pursuant to 10 CFR 50.59 7.8(3)(e) Summary of Radioactive Material Released and Results of Environmental Surveys Performed

- 7.8(3)(f) Summary of Significant Exposures Receiv'ed by Facility Personnel and

-Visitors

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1990 Operations _ Report for _ NBSR (TR-5)

.[ Docket _#30-184]

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• Pago 2 7.8(3)(a) Summary of Plant Operations During the calendar year 1990, the reactor was critical for 3963 hours0.0459 days <br />1.101 hours <br />0.00655 weeks <br />0.00151 months <br /> and the energy generated was 72,581 MWH.

The reactor was shutdown until April,1990 for the installation of the first three guide tubes of the Cold Neutron Facility. The shutdown period was used to perform maintenance and improvements. Highlights of significant activities during 1990 are presented below:

1. Guide Tubec and Confinement Building: Three of seven guide tubes equipped with isolation valves were completed. The remaining four penetrations were sealed for future installation. The confinement building was painted with sealant paint and the roof was replaced. Subsequently, an integrated leak test was performed and the confinement building easily passed its leak rate requirements.

2. Shim Arms and Drives: The bearing-seal assemblies on all four shim arms were replaced. Details were included in an information letter dated September 28, 1990, in addition, all drives were cleaned and overhauled where necessary.

Two problems were encountered with Shim No.1, one involved the drive mechanism and the other was due to the failure of one of the relays. These were covered by separate letters dated April 25,1990 and September 25,1990 respectively.

3. lon-Exchange Columns: During the shutdown,it was noted that the flow through the main IX-column was gradually decreasing. Inspection of both the pre and after filters showed that the after filter was clogged with resin. The resin was removed and the filter replaced. Repeated inspections down stream showed a small amount of resin beads in the experimental cooling system which were also removed. Subsequent checks showed no more resin beads in the system. One depleted IX column, considered the main suspect, which had been valved out was physically isolated. The after filter continued to be monitored. When the resin reappeared in the filter, the on-line IX-column was isolated. The depleted resin was removed and disposed of. It appears that one of the screens in the column either became loose or developed a tear thereby allowing some of the resin to escape.

-4. Heat Exchangers: Repeated attempts to find a very smallleak in one of the main heat exchangers have been for the most part unsuccessful. The leak is so smali,

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1990 Operations Report for NBSR (TR-5) .

[ Docket #50-184]

• Pago 3

- bn the order of a few drops a minute, that it is virtually impossible to find. All tubes that were suspect, even in the slighest, were plugged. It is planned to temporarily take the unit out of service next year in the hope of locating the smallleak.

Negotiations for new plate type heat exchangers are expected to be completed by mid-1991 with delivery expected in the summer or fall of 1992. Emphasis on reliability and zero leakage have been incorporated in the selection and design of the new heat exchangers.

5. Thermal Shield Cooling System: Treatment of the thermal shield cooling system is continuing. Slow, steady improvement has been noted in the number of affected tubes and the size of the leaks. Severalimprovements were made to the system. The treatment orogram will continue on a regular basb.

7.8(3)(b) Unscheduled Shutdowns

1. There was one (1) scram due to a commercial power dip. Because it was late in the fuel cycle there was no attempt to return to power.

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2. There were four (4) scrams due to commercial power dips during electrical storms. The reactor returned to power immediately in each case.

3. There was a major scram caused by a momentary trip of the irradiated air monitor.

There was excess air in the helium sweep system due to the opening of systems for maintenance resulting in higher Ar41 levels than normalin the system.

Normally, during startup the levelin the helium gas holder increases due to system warmup and is relieved by exhaust to the irradiated air system through a relief valve. This results in a momentary rise in the irradiated air monitor and in l

this instance caused the scram. Analysis confirmed the higher Ar41 levelin the helium sweep system and the reactor was returned to power. The stack monitor did not trip and there was no measurable release of activity above normal.

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4. There was a major scram of the reactor caused by the failure upscale of the Normal Air Monitor when the main frame ampilfier failed. Continuing spikes on the channel made it impossible to return to power at the time although other

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1990 Operations Report for NBSR (TR-5)

(Docket #50-184]

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Page 4 rnonitors remained normal and stable and the reactor could be operated without this monitor.

5. There was a major scram of the reactor caused by an instrumentation spike on the Stack Monitor channel as a result of a momentary electric power source fluctuation; The reactor was returned to power.

7.8(3)(c) Tabulation of Major items of Plant Maintenance

1. Regenerated Demineralized water station IX column (3 times).

2. Replaced sightglass on the Demineralized water storage tank on B 2 level.

3. Reactor bulk helium system placed in service.

4. Replaced #1 RD 3 4/3-5 bio %r with new unit.

5. Changed "O" rings in Ficxo rabbit system B wing /C-002 switch.

6. Replaced control power transformer for #3 Cooling Tower fan.

7. Replaced control coil in #3 Cooling Tower fan controller.

8. Replaced reset relay in #4 Secondary Main circulating pump.

9. Changed thermal overloads on both Secondary Aux cooling pumps.

10. Installed 5 new cells of Station Battery #14, #15, #39, #40, & #41.

11. Replaced oil. diaphragm on Secondary system acid addition pump.

12. Replaced oil diaphragm on Secondary system product addition pump.

13. ' Rebuilt operator for SVC-4 (air operated cooling tower level control valve).

14. Installed "Lakos Seperator"in the Secondary Aux cooling system.

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15. . Changed resin in both Thermal Shield IX colurnns (2 times),

16. Changed pre and after filter elements of the Thermal Shield system purification loop.

17. Changed valve diaphragms of the following Thermal Shield valves: TSV 1,2,20, 25, 26, 29, 30, 31, 32, 34,' 35, 36, 37, 39, 40, & l45.

18. Removed heads of both Thermal Shield IX columns and cleaned' flow distribution " tree".

19. -installed plate type heat exchanger in Thermal Shield cooling system.

20. Treated numerous leaking Thermal Shield cooling coils to stop/ minimize leakage.

21. Replaced Regulating Rod drive mechanism with spare (2 times).

22. Removed, cleaned and reinstalled lead screw & ball _ nut assembly, replaced taper bearing as well as upper shaft bearing and inner bearing & shaft seal of #1 Shlm Arm drive mechanism.

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1990 Operations Report for NBSR (TR-5)

[ Docket #50-184]

9 Pago S

23. Replaced lead scrow a ball nut assembly, outor bearing, and innor boaring &

shaft seal of #2 Shim Arm drive mechanism.

24. Romoved, cleaned and reinstalled load scrow & ball nut assembly, added brako fluid to shock, rolpaced innor bearing and shaft seal of #3 Shlm Arm drive mechanism.

25. Removed, cleaned and reinstallod load scrow & ball nut assembly, added brake fluid l to shock, replaced outor bearing as well as inner bearing & shaft soal of #4 Shim Arm drive mechamism.

26. Adjusted upper and lower limit switches of all four Shlm Arms.

27. Repaired Refueling drop out tool by replacing the connocting pin.

28. Replaced all nine hydraulic cylindors of the Fuel Elomont cutting saw.

29. Cut 32 spent fuel elomods to increase storago capacity in Fuel storage pool.

30. Installed float switch in the spnt Fuel storago pool sump pit to provent ovorfilling when the makeup valvo is in the automatic modo.

'31. Changed pro and attor filtor elements of the Fuel storago pool system purification loop.

32. Replaced valvo diaphragm of DWV 6 (air operated dischargo valvo of #4 Main D2 O pump).

33. Replaced pro and after filter elomonts of the D2O Purification system twico.

34. Removed deptoted resin from #1 & #2 IX columns of the D 2O Purification systom.

35. -- Installod now piping on both Experimental D2 O pump casing drains,

36. Replaced aluminum piping on the Hp and L pconnections of FIA 18 (D20 Injection flow) v;lth stainless stool fittings.

37. Replaced aluminum piping on the Hp and L pconnections of FIA 6 (D20 IX flow) with stainless stool fittings.

38. Checked tightness of all electrical connections in #1 & #2 D2O shutdown pump AC.& DC controllers. Continuity checks also satisfactory.

39. _Repalrod leak on #4 Main D2O pump casing vont ponotration.

40. Changed after filter olomonts of the Experimental Domineralized system purification loop.

41. Changed IX resin in Exporlmental Domineralized water system.

42,. . Replaced valvo position micro switch on both Holium Blower dischargo valves.

- 4 3. Installed flow motor (GPH) on the outlet of RT 1 cooling lino.

44.. Replaced low flow mon _itoring instrument at the outlet of RT 1 cooling lino.

45. Replaced actuator diaphragm of DWV 7 (#2 D2 0 Shutdown pump).

46. Installed ball valve and too for sampling the secondary sido of HE t A&B.

1990 Operations Roport for NBSR (TR-5)

[ Docket -#50-184)

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I Pago 6

47. Pluggsd leaking tubes of Main Heat exchanger HE 1 A : 17/23,23/23,25/9,25/47,

'27/9,28/42, 34/48,37/33,37/45,38/24,38/32,39/33,39/47,40/40,40/34,40/36, 40/44,42/26,43/3.

48. Checked and tightened as necessary all plugs in leaking tubes of Main Heat L exchanger HE 1 A. ,

49. The following instrument calibration surveillance tests were performed:

' RM 31 N 16 Monitor Calibration NC SA Linear Power Range Calibration FR1 Reactor Outlet Flow Calibration TR 1' Reactor Delta Temperature Calibration RM34 Irradiated Air Monitor Calibration RM 1 1 to 10 Area Radiation Monitor NC 7 Nuclear Power Range Calibration LIA 40 Reactor Level Calibration NC 8 - Reactor Power Range Calibration NC 4 . Reactor Intermediate Range Calibration BTUR Thermal Power Channel Calibration FCA 7 Thermal Column Flow Calibration RM41 Stack Monitor Calibration

' FRC 3 inner Plenium Flow Calibration FRC 4 ' Outer Plenium Flow Calibration RM 4-2. Auxillary Stack Monitor Calibration LRC 1 Reactor Level Calibration NC 3 Reactor intermediate Range Calibration

-RM35 Normal Air Monitor Calibration PC 3- Normal Exhaust Pressure-Controller

~ PC 27 - Process Room Pressure Controller SPCL150 - Emergency Fan Controller.

SPS 151 -Vacuum Breaker Controller SPS 150- Emergency STBY Fan Controller NC 9 Calibration Procedure of Nuclear System NC.6- Power Range Calibration

.FIA 40 Reactor Outlet Flow Calibration

' TIA 40A Reactor Delta Temperature 1990 Operations Report for NBSR (TR-5)

[ Docket #50-184]

• Page 7 LIA 40 Reactor Level Calibration RM31 N 16 Calibration RM33 N 16 Calibration RM 3 2 - Fission Product Monitor

50. System calibration Replaced seal on #2 Shim, aligned readout.

51. Verified Scram System relay contact operation.

52. Replaced faulty K 103 Scram relay.

7.8(3)(d) Tabulation of Major Changes in the Facility and Procedures, and the Test and Experiments, Carried Out Without Prior Approval by the NRC pursuant to 10 CFR 50.59.

Relevant Engineering Changes are summarized below:

ECN 347 ' /. two (2) ton bridge crane was installed at the Spent Fuel Storage Pool.

The crane was originally planned fnr the area with structural components built during the construction of the building. There is no unreviewed safety question.

ECN-365 The first three of seven guide tubes including isolation valves were completed. The remaining four penetrations remain sealed and their guide tubes will be installed later. This ECN documents an approved change to the NBSR technical specifications. The confinement building and the isolation valves were -

subsequently tested and met technical specifications requirements. Accordingly, there are no unreviewed safety questions.

j ECN 366, ECN 367 and ECN 368  : As part of the generalimprovement of the thermal shield system principally to reduce tube leakage, a new modern plate type stainless steel heat exchanger was installed to replace the old one. Also, a "LAKOS" sediment separator was installed in the Auxiliary Secondary Cooling System to provide cleaner water to the new heat exchanger and to other components in_the system. In addition a temperature controller, similar to that for the

, secondary system, was added to regulate temperature and prevent significant fluctuations that could possibly cause tube leakage. These changes are simple i

maintenance and improvement items that in generalinvolve replacement of old 1990 Operations Report for NBSR (TR-5)

[ Docket #50-184) l

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" ' omponents c with new modern ones. They do not affect, and in fact they improve, the operation and performance of the system. There are no unreviewed safety questions.

7.8(3)(e) Summary. of Radloactive Material Released and Results of Environmental Surveys Performed.

The gaseous waste released was 309 curies of tritium and 687 curies of Argon 41.

There were 2.2 curies of tritium and 1.1 millicuries M other beta-gamma emitters released into the sanitary sewer. Environmental samples of the streams, vegetation, and/or soil, and air showed no significant changes.

7.8(3)(f)_ Summary _of Significant Exposures Received by Facility Personnel and Visitors.

1. None to visitors.

2. Dosimetry results for this reporting period indicated that rio facility personnel received significant exposures.

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1990 Operations Report for NBSR (TR-5)

(Docket - #50-184]

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