ML19331D785

Mit Research Reactor Annual Rept,Jul 1979-June 1980.

ML19331D785
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Issue date:	08/26/1980
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MIT "2 SEARCH REACTOR ANNUAL RFKGT TO UNITED STATES NUCLEAR REGULATORY CONNISSION FOR THE PERIOD JULY 1,1979 - JUNE 30,1980 I

BY REACTOR STAFF 4

August 26, 1980 4

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TABLE OF CONTENTS Section Introduction 1 A. Suzanary of Operating Experience 3 B. Reactor Operation 9 C. Shutdowns and Scrams 10 D. Major Maintenance 13 E. Section 50.59 Changes, Tests and 15 Experiments F. Environmental Surveys 20 G. Radiation Exposures and Surveys 21 H. Radioactive Effluents 22 l

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1 MIT RESEARCH REACTOR ANNUAL REPORT TO UNITED STATES NUCLEAR REGULATORY COMMISSION FOR THE PERIOD JULY 1. 1979 - JUNE 30, 1980 Introduction l

This report has been prepared by the staff of the Massachusetts Insti-tute of Technology Research Reactor for submission to the Director of Region 1, United States Nuclear Regulatory Commission, Office of Inspection and Enforcement, in. compliance with the requirements of the Technical Speci-fications to Facility Operating License No. R-37 (Docket No. 50-20), Para-graph 7.13.5, which requires an annual report following the 30th of June of each year.

The MIT Research Reactor (MITR), as originally constructed, consisted of a core of MIR-type fuel, fully enriched in uranium -235 and cooled and moderated by heavy water in a four-foot diameter core tank, surrounded by a graphite reflector. After initial criticality on July 21, 1958, the first year was devoted to startup experiments, calibration and a gradual rise to one megawatt, the initially licensed maximum power. Routine three-shif t operation (Monday-Friday) commenced in July 1959. The authorized power level was increased to two megawatts in 1962 and five megawatts (the design power level) in 1965.

Studies of an improved design were first undertaken in 1967. The con-capt which was finally adopted consisted of a more compact core, cooled by light water, and surrounded laterally and at the bottom by a heavy water reflector. It is undermoderated for the purpose of maximizing the peak of thermal neutrons in the heavy water at the ends of the beam port re-entrant thimbles and for enhancement of the neutron flux, particularly the fast ,

component, at in-core irradiation facilities. The core is hexagonal in H shape,15 inches across, and utilizes fuel elements which are rhomboidal in cross section and which contain UxAl intermetallic fuel in the form of plates clad in aluminum and fully enriched in uranium-235. Much of the original facility, e.g. graphite reflector, biological shield, cooling sys-tem, containment, etc., has been retained.

Af ter Construction Permit No. CPRR-118 was issued by the former U. S.

. Atomic Energy Commission in April 1973, major components for the modified reactor were procured and the MITR-I was shut down on May 24, 1974, having logged 250,445 megawatt hours during nearly 16 years of operation.

!The old core tank, associated piping, top shielding, control rods and  !

drives, and seme experimental facilities were disassambled, removed and subsequently' replaced with new equipment. After preoperational tests were conducted on all nystems, the U. S. Nuclear Regulatory Commission issued Amendment No.10 to Facility Operating License No. R-37 on July 23, 1975.

After initial criticality for MITR-II on August 14th 1975 and several

~ months of startup testing, ' power was raised to 2.5 MW in December. Routine l 5 MW operation was . achieved in December 1976. l l

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7 This. is the fif th annual report required by the Technical Specifica-tions, and it covers the period July 1,1979 through June 30, 1980. Pre-vious reports, along with the "MITR-II Startup Report" (Report No. MITNE-198, February.14,1977) have covered the startup testing period and the transition to relatively routine reactor operation. This report covers the third full year of routine reactor operation at the 5 MW licensed power level. It was a year in which the safety and reliability of reactor operation fully met the requirements of reactor users. A summary of operating experience and other activities and related statistical data are provided in the following Sections A - H of dhis report.

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A.

SUMMARY

OF OPERATING EXPERIENCE ,

1. General During the period covered by this report (July 1, 1979 - June 30, 1980), the MIT Research Reactor, MITR-II, was operated on a routine, four days per wee:k schedule, normally at a nominal 5 MW. It was the third full year of normal operation.

The reactor averaged 83.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> per week at full power compared to 79.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> per week for the previous year. During a week when there is no holiday, major maintenance, long experiment changes, vaste shipping, etc. , the reactor is at power for 90 - 95 hours0.0011 days <br />0.0264 hours <br />1.570767e-4 weeks <br />3.61475e-5 months <br />.

In the second half of FY79 (i.e. MIT's fiscal year, July through June), operating hours were curtailed scmewhat as a measure to conserve fuel when the fuel fabricator's delivery schedule began slipping badly.

At the beginning of FY80, the fuel re-order appeared much more certain, and so operating hours were again increased. Also, the change from a 24 to a 25 element core (mentioned below) added sufficient reactivity so that greater burnup (an element average of about 40%) than planned be-came possible and stretched out the existing fuel supply.

In August 1979 the reactor reverted to the earlier Monday-Friday operating schedule, with maintenance scheduled for Mondays and, as necessary, for Saturdays.

The reactor was operated throughout the year with either 24 or 25 elements in the core. The remaining two positions were occupied either by irradiation facilities or by solid aluminum dummy elements. Compen-sation for reaccivity lost due to burnup was achieved for the first four months of the year by replacing many of the relatively fresh B-Ring ele-ments with moderately spent fuel and, in the process, converting from a 24 to a 25 element core. Compensation for reactivity lost due to burnup was achieved during the last eight months of the year by making five re-fuelings in which the relatively fresh elements originally removed from the B-Ring were gradually reinserted. Elements being removed from the B-Ring during these refuelings were used to replace C-Ring elements that were approaching the end of their useful life. In addition, there were two refuelings involving fresh fuel. The first involved introducing three of the more highly-loaded elements (nominally 510g. U-235 as de-scribed in Section A.3 of this report) to the B-Ring while the second entailed insertion of the last of the original MITR-II elements (445g.

U-235) into the A-Ring.

There were four other fuel shuffles. One in August 1979 reinserted fuel that had been removed during a search for an element with faulty cladding. The other three were temporary core configurations used only to obtain axial flux scan data. None was operated at more than 500 watts for more than an hour.

Protective system surveillance tests are conducted on Friday evenings af ter shutdown (about 1800), on Mondays, and on Saturdays as necessary.

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. As in FY78, dme reactor was operated throughout the period without the fixed hafnium absorbers, which were designed to achieve a maximum peaking of the thermal neutron flux in -the heavy water reflector beneath the core. These had been removed in November 1976 in order to gain the

. reactivity necessary to support more in-core facilities.

2. Experiments The MITR-II was used throughout the year for experiments and irradi-ations in support of research and training programs at MIT and elsewhere.

Experiments and irradiations of the following types were conducted:

a) Neutron diffraction spectrometer alignment and studies (4 ports) .

b) Molecular dynamics studies with an inelastic scattering spectro-

< meter, c) Dosimetry measurements of the neutron beam in the medical

. therapy facility in preparation for animal studies.

i l d) Dosimetry measurements for pneumatic rabbits and other irradi-ation. facilities.

e) Irradiations of biological, geological, oceanographic, and medi-cal specimens for neutron activation analysis purposes.

f) Activation of ablation monitor wires for re-entry vehicles.

g) Production of phosphorus-32, gold-198, and dysprosium-165.

h) Irradiation of tissue specimens on particle track detectors for l

plutonium radiobiology, of steel for boron location, and of geo-logical samples for fissile element distribution.

1) Use of the facility in reactor operator training.

j j) Irradiation damage Lcudies of candidate fusion reactor materials.

i k) Studies of fatigue failure as a function of surface bombardment and bulk irradiation damage. ,

11 Components of a safeguards system of interest to the Arms Con-

! tr ' and Disarmament Agency for monitoring the security of reae ors and special nuclear materials were installed in various

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parts of the reactor facility and tested, j m) Plans were initiated for recording the output of control and pro-cess channels from the MIT Reactor as part of a study leading to 1 - analysis of power reactor signals by computer.

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3. Changes to Facility Design As indicated in last year's report the uranium loading of MITR-II fuel is being increased from 29.7 grams of U-235 per plate and 445 grams per element to 34 and 510 grams respectively. The new loading results in 41.2 w/o U in the core, based on 7% voids, and corresponds to the maximum loeiing in Advanced Test Reactor (ATR) fuel. The fuel fabricator, Atomics International Division of Rockwell International, completed the production of 25 of the more highly loaded elements in December. Three of the first four shipped have been in operation in the core since January of this year. The remaining 21 are in storage at AI and will be shipped to MIT as needed over the next two years.

One of the containment building hot cells described in last year's report was completed during the year and placed in operation. Two remote manipulators have been added. The cell has been used principally for examining and handling the capsules used in the above - mentioned fatigue failure studies. The second cell should be completed during the coming

year.

Other changes in the facility are reported in Section E.

4. Changes in Performance Characteristics Performance characteristics for the MITR-II were reported in the "MITR-II Startup Report", and no significant changes have occurred since that time.

5. Changes in Operating Procedures Related to Safety There were no amendments to Facility Operating License No. R-37 or to the Technical Specifications during the year. MIT's letter of March 13, 1980 to USNRC's Office of Nuclear Reactor Regulation requested a license amendment that would authorize the receipt, possession and use of byproduct materials activated in reactors other than the MITR.

With respect to operating procedures, a summary of those related '.o safety is given below:

a) A revision to the equipment tag-out procedure (Procedure Manual 1.14.3), initiated during the prior year, was instituted during FY1980 (Safety Review #0-78-24) . A tag-out status board has been added to the procedure.

b) A formal procedure (PM 7.4.4.2) for the inservice inspection of the primary core tank and fuel, initiated during the prior year, was instituted during FY1980 (SR # 0-78-27) .

c) Procedure PM 3.10.1, which had been written in the prior year for sectioning and disposal of the old MITR-I core tank, was used for the above purposes in FY1980 (SR #0-79-1) . The core tank and other waste were shipped to Barnwell, So, Carolina in October 1979, using Chem-Nuclear Systems , Inc. , cask #LL-50-100.

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I d) ' Procedure PM 7.4.5.1 was written to provide an in-house method for

. calibrating the gas meter used in the annual containment building .

leakage test.

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! .e) Procedure PM 1.22 for reporting defects under 10CFR21 was revised

- (1) .to incorporate a 10CFR21 change regarding " commercial grade items" and (2) to extend coverage of the procedure to special nuclear material held under MIT licenses other than Facility

. License No..R-37.

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, f) The " Emergency Plans for the MIT Reactor", SAR Appendix 13.A.1, and 4

implementing procedures in Section 4 of the Procedure Manual were a updated (SR #0-79-13, #0-79-15, #0-80-11 and #0-80-18). There were no substantive changes. As noted in Section E, Appendix 13.A.1 was submitted to NRC as SAR Revision No. 19 in March 1980.

g) Procedure PM 3.1L4 was prepared to provide a written procedure for removal, inspection and re-insertion of an experiment capsule in-stalled in one of the in-core irradiation positions (SR #0-79-14) .

h) Procedure PM 6.1.5.2 was prepared to provide a written procedure for testing of the Campus-Patrol radio-telephone patch by which reactor personnel can coinnunicate directly with the Campus Patrol cruiser (SR #0-79-16).

1) Procedure PM 3.11.3 was prepared to provide a written procedure for verifying the operability of several alarms associated with an in-core experiment prior to operation of the experiment (SR #0-79-18).

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j) Chapter 1 of the Procedure Manual, Administrative Procedures, was i updated in many areas, i.e. organization, charts, security, super-

, visor duties, circulation of safety reviews,' log maintenance, pro-i tactive clothing requirements, potential dose rate changes, refuel-ing procedure requirements, audits, review and approval of preopera-tional tests, and miscellaneous other changes (SR #0-79-23, -35, -36, i #0-80-6 and 0-80-15).

i A set of procedures for Procedura Manual Section PM 3.12 was prepared k) to establish limitatior 3 and guidelines for use of the two hot cells installed in the containuent building '(SR #0-79-24).

1) Procedure PM 2.6.7 was prepared in response to NRC Region #1 Immediate g Action Letter 79-14 for the purpose of instituting a new procedure

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designed to achieve compliance with radiation protection procedures and to provide ~a method for documenting violations and corrective actions (SR #0-79-25).

. m) A one-time procedure was written and used to demonstrate that the fuel transfer flasit lif ting mechanism has an adequate safety factor (SR #0-79-26).

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..- 7' n)- Procedure PM 7.5.1' was prepared to provide a writt'en procedure and a better record of ion chamber and fission chamber replacements

(SR #0-79-28) .

o) Procedure FM 7.5.2 was prepared to provide instructions for pre-1 .ventive maintenance on Leeds and Northrup indicating instruments i and to provide a record of such maintenance (SR #0-79-29).

1 p) ~ Procedure PM 6.5.16.2 was revised to insure that neutron' shadowing effects are avoided during calibration of shim blades against the i regulating rod and against each other (SR #0-79-30).

i q) Procedure FM 3.10.2 was prepared to provide a written procedure for 7 the sectioning and disposal' of radioactive rubble from the MITR-I i modification . (SR #0-79-31) . The rubble was shipped to Barnwell, So.

Carolina in November 1979 using Chem-Nuclear Systems Inc. cask

#LL-50-100.

, r) Procedure PM 6.5.16.1 for calibration of the regulating rod was

, revised to document the worth of the rod in comparison with the Technical Specification requirements and to provide an improved data sheet (SR #0-79-32) .

l s) Procedures PM 6.5.6.2 and 6.5.6.3 for the calibration of system pressure gages were revised by adding to each procedure the j specific list of gages to which each applies (SR #0-80-1).

t) Procedures FM 1.16.2 and 1.16.3 established extensive checklists for documenting the training programs for operators and for senior i operator /shif t supervisors (SR #0-80-3 and #0-80-20).

u) Procedure PM 1.16.1 was revised to require that licensed personnel

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who score less than 80% in any category of the annual examination will undergo retraining in that category (SR #0-80-5) .

v) A general review was made of startup and shutdown checklists in Chapter 3 of the Procedure Manual. Except as noted in (w) (x)

below the changes made were not substantive and not related to

safety, although the general improvement in the checklists should j increase safety (SR #0-80-14).

w) Procedure PM 3.2.4 was prepared to provide a written procedure for ,

responding to alarms received at Campus Patrol Headquarters from t t the reactor when the containment building is secured (generally J

over weekends) . It contains. cautionary steps related to-potential radiation and fire hazards, provides for systematic checks, and specifies the steps for properly securing the building after re-

,-_ sponding to an alarm (SR #0-80-14). In order to reduce the number P of weekend nuisance alarms, the system was modified to initiate -

alarms only for a number of selected conditions for which a prompt y response was judged to be desirable, such as high core tank tempera-1 ture, low core tank level, high radiation, smoke, etc. (SR #E-79-7).

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. . 8 x) Procedure FM 3.3.1 and FM 3.3.1.1 supersede previous checklists used for refueling and other fuel handling. The procedures are not changed, but some checklists have been combined to avoid duplication, and a number of cautionary checks have been added (SR #0-80-14) .

y) Miscellaneous minor changes to operating procedures and equipment were approved and implemented throughout the year.

6. Surveillance Tests and Inspections There are many written procedures in use for surveillance tests and inspections required by the Technical Specifications. These procedures provide a detailed method for coaducting each test or inspection and speci-fy an acceptance criterion which must be met in order for the equipment or system to comply with the requirements of the Technical Specifications.

The tests and inspections are scheduled throughout the year with a frequency at least equal to that required by the Technical Specifications. Twen ty-three such tests and calibrations are conducted on an annual, semi-annual or quarterly basis.

Other surveillance tests are done each time before startup of the reactor if shut down for more than 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />, before startup if a channel has been re-paired or de-energized, and at least monthly; a few are on different schedules.

Procedures for such surveillance are incorporated into daily or weekly startup, shutdown or other checklists.

During the reporting period, the surveillance frequency has been at least equal to that required by the Technical Specifications.

The results of tests and inspections required by the Technical Specifi-cations have been satisfactory with one exception (Reportable Occurrence

1. 50-20/80-1); NRC was notified in accordance with Technical Specification 7.13 in this case. Conditions having safety implications were found as the result of other tests and inspections and were likewise reported to NRC (Re-portable Occurrences # 50-20/79-5 and #50-20/80-2) .

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9 B. Reactor Operation Information on energy generated and on reactor operating hours is tabu-lated below:

Quarter Total 1 2 3 4

1. Energy Generated (MWD):

a) MITR-II (MIT FY80) 213.5 208.5 232.8 210.5 865.3 (normally at 4.9 MW) b) MITR-II (MIT FY76-79) _2,552.6 c) MITR-I (MIT FY59-74) 10,435.2 d) Cuculative, MITR-I & MITR-II 13,853.1

2. Hours of Operation, MIT FY1980, MITR-II a) At Power (>0.5 MW) 1106.6 1033.2 1137.5 1044.7 4,322.0 for research b) Low Power (< 0.5 MW) 50.2 87.0 19.8 27.3 184.3 for training (1) and test c) Total critical 1156.8 1120.2 1157.3 1072.0 4,506.3 Note: (1): These hours do not include training conducted while the reactor is at full power for research purposes (spectrometer, etc.) or for isotope production. Such hours are included in previous line.

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, 10 C. Shutdown and Scrams During the period of this report there were 30 inadvertent scrams, and 20 unscheduled power reductions or shutdowns.

The tarm " scram" refers to shutting down of the reactor through pro-tactive system action when the reactor is at power or at least critical, while the term " reduction" or " shutdown" refers to an unscheduled power re-duction or shutdown to suberitical by the reactor operator in response to an abnormal condition indication. Rod drops without protective system action are included in shutdowns.

The following sunwnary of scrams and shutdowns is provided in approxi-mately the same format as last year in order to facilitate a comparison.

I. Nuclear Safety System Total a) Period channels during normal startup, resulting from electrical noise. 6 b) Electric Company Power Dips. 1 c) Level channel tripped on high level due to trip being set slightly under 5 MW (should be about 5.5 dn0 2 d) Electronic component failure (coaxial cable) 3 e) Operator error in deactivating or switching channels 2 f) Technician error in doing maintenance 4 g) Failure of a chamber (Channel #5) 5 Sub total 23 II. Process Systems a) Low flow secondary coolant due to trip of one secondary pump breaker on thermal overload 1 b) Low pressure primary system indication due to improper valve line-up in secondary system. (Primary system was functioning properly; caused by momentary pressure pulse transmitted by Lamella heat exchanger). 1

, c) High temperature primary system due to trip being set too' low 1 d) High temperature primary system due to electronic noise on recorder 2 e)' Operator action af ter misreading an alarm signal 1

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Low flow primary coolant due to trip of one primary coolant pump circuit breaker on overload. (This may have been due to a transient ground on one phase of the externally-supplied electric power.) 1 Subtotal 7 III. Other Scrams or Unscheduled Shutdowns a) Operator shutdown by "All Rods In" to investigate

1) D20 system conductivity 1

11) Improper or lack of response of a period or level channel 5 111) D2 0 flow recorder malfunction 1 iv) Loss of helium supply to an irradiation thimble 1 v) Loss of ventilation due to loss of externally-supplied steam 1 vi) Railroad tank car accident in adjacent town (leakage of hazardous chemical) 1 vii) Blade drops due to blade magnet failure 2

viii) Binding of a shim blade due to a small piece of foreign material in the blade's slot or guide tube (Reportable Occurrence #50-20/80-2) 1 ix) Flow /AT recorder 1

) b) Operator lowered power to 500 Kw to investigate spike on core purge monitor 1 1

c) Operator lowered power to 2.5 MW to:

i) Investigate thermal overload on regulating rod breaker 1 i 11) Investigate partial run-in on blades 5 and 6 caused by technician error 1 iii) Temporary loss of cooling tower fans due to faulty vibration switches. 3 Subtotal 20 Total 50

12 A study of the above list reveals that only four scrams or shutdowns are attributable to extecta1 causes (off-site power dip or ground, build-ing steam loss, railroad accident). Twelve were the direct result of per-sonnel actions (wrong instrument settings, inadvertent circuit interference during at-power maintenance, wrong valve line-up, insufficient cicanliness).

Twenty-five were instrumentation or cabling failures. To a significant degree, scrams and shutdowns of the types in the last two categories are within the control of reactor personnel. Efforts are being made to reduce the frequency through continued instrument upgrading, preventiva maintenance, and improved procedures and practices.

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13 D. Major Maintenance Major maintenance projects during FY80, including the effect, if any, on safe operation of the reactor, are described in this section.

1) A program to upgrade instrumentation was continued during FY80.

Because of excessive maintenance and obsolescence on older units, some of which had been in use since the initial operation and for which it is increasingly difficult to obtain spare parts, several components were replaced with new units having equivalent or im-proved characteristics. These included a new radiation monitor multi-point recorder, a simulated level generator for testing and calibrating level. channels, solid-state count rate amplifiers and scalers for the startup channels, and process system instru-mentation. Several coaxial cables for neutron chambers were re-placed. The preventive maintenance program has been revised and extended to provide increased reliability of the instrumentation systems.

2) Two shipments of radioactive components from the MITR-I reactor were made during the year. The first shipment disposed of the old MITR-I core tank in Chem-Nuclear Systems, Inc., No. LL-50-100 cask. Samples of the core tank were retained for possible studies of radiation damage effects in aluminum. The second shipment, using the same cask, contained assorted rubble from dismantling of MITR-I. A third and final shipment is required, but many delays in obtaining a burial allocation at Barnwell, S. C., and use of the shipping container resulted in postponement of the third ship-ment until FY81.

3) Further work was done on gaskets related to the reactor contain-ment building. The rubber gasket on the exhaust auxiliary damper was replaced after signs of wear were noted. It was shown by in-spection and test to provide the necessary seal. The gasket on the outer door of the truck lock, which had been replaced in April 1979, did not provide an adequate seal during the April 1980 building pressure test (Reportable Occurrence # 50-20/80-1). It was found to be more difficult to make a good seal at all points with the harder rubber installed in 1979 than with the sof ter rubber that had previously been used. A new gaske'. of the origi-nal type has now been procured. It will be insta' led and tested shortly. Meanwhile building integrity is maintained by the inner door.

4) The containment building heating and air conditioning system was overhauled and partially rebuilt. New pneumatically-operated temperature and humidity controls were installed to replace the original electrically-operated controls. This involved a 10CFR50.59 change,' which is described under Section E.

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5) Two of the six electro-magnets that couple control blades to the drive mechanisms failed during the year and had to be replaced.

6) Af ter the heavy water system. conductivity meter began to require extensive recalibration and maintenance, it was replaced with a new Bechman mater similar to the one on the primary system.

7) Many other routine maintenance and preventive maintenance jobs were done throughout the year.

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15 E. Section 50.59 Changes Test and Experiments This section contains a description of each change to the facility or procedures and of the conduct of tests and experiments carried out under

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the conditions of Section 50.59 of 10 CFR 50, together with a summary of the safety evaluation in each case.

, The review and approval of changes in the facility and in the procedures as described in the SAR are documented in the MITR records by means of

" Safety Review Forms". These have been paraphrased for this report and are identified on the following pages for ready reference if further information should be required with regard to any item. Pertinent pages in the SAR have

, been or are being revised to reflect these changes, and they will be forward-ed to the Chief, Standardization and Special Projects Branch, Division of Licensing, USNRC.

The conduct of tests and experiments on the reactor are documented in the experiments and irradiations files. During FY 1980 all experiments have been done in accordance with the descriptions provided in Section 10 of the SAR, " Experimental Facilities".

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1. SR #E-79-5 (4/27/79)

Startup Channel Modifications Startup Channels #1 and #2 were modernized by replacing vacuum tubes with solid state circuits as part of the program to upgrade instrumentation described in Section D-1. As part of the change, an ion chamber was added to Channel #1 to provide period indication and scram in the power range, making it the same as Channel #2. This will normally provide a third period channel in the power range and will provide backup in the event that either of the other two fail. The SAR description for Channel #1 (Subsection 7.1.1.2.1) will be changed accordingly in a subsequent SAR revision.

Reactor Staff approval 10/5/79

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2. SR #0-79-13 (6/8/79)

Update of Emergency Plan and Procedures Appendix 13.A.1 of the SAR contains the " Emergency Plans for the MIT Reactor". Implementing procedures are in Section 4 of the MITR Procedure Manual. The plans were updated in several respects; none are substantive.

Reactor Staff approval 8/1/79 MIT Reactor Safeguards Committee apprsval 11/21/79 Revisions to Appendix 13.A.1 were submitted to NRC as SAR Revision No. 19 in a letter dated 3/12/80.

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3. SR #E-80-1 (6/5/80)

Primary Flow Backup Scram A direct reading of primary flow is provided by the new flow-AT recorder, which obtains its reading from a new D/P cell that was installed across an orifice in the primary coolant supply line when the new recorder was acquired.

The original D/P cell, used with the same orifice for the previous recorder, now provides a signal for an optical meter that has been calibrated .to i 5 GPM.

When switched into the withdraw permit circuit, it causes a scram on either low flow or loss of power to the instrument.

The optical meter scram switch is wired in parallel with the recorder scram switch, and either can be selected by means of a two-position key switch. The optical meter has been used to provide backup flow indication in the control room but not to function as one of the safety channels required by Technical Specification 3.7-1, pending further review and experience with its performance. Before its use as a required safety chanael, the startup checklists and test and calibration procedures will be revised to provide the surveillance and calibrations required by Technical Specifications 4.3-lb and 4.3-2c. SAR Fig. 7.3a2 will be changed as indicated above in a subsequent -

SAR revision.

Reactor Staff approval 6/6/80

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4. SR #M-80-2 (4/10/80) ,

Containment Penetrations for Air Conditioning System During overhaul of the containment building air conditioning system the controls were changed from electrical to pneumatic. This required three additional penetrations for 1/4" 0.D. instrument air lines. Criterion 56 of Appendix A,10CFR50, for penetrations that connect directly to the contain-ment atmosphere allows special provisions for specific classes of lines, such as instrument lines. The lines are open to the containment atmosphere through two 0.020" diameter orifices, and thus they are similar to the in-strument lines described on SAR pages 16.17a and b, except that each line is equipped with a manual isolation valve just outside the containment. The lines comply with the recommendations of Regulatory Guide 1.11.

Reactor Staff approval 4/10/80 l

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• 20 F.. Environmental Surveys Environmental surveys, outside the facility, were performed using area monitors. The systems (located approximately in a 1/4 mile radius from the reactor site) consist of calibrated G.M. detectors with associated electronics and recorders.

The detectable radiation levels due to Argon-41 are listed below:

Site July 1, 1979 - June 30, 1980 North 1.7 :uR South 1.2 mR East 3.8 mR West 2.3 mR Green (East) 0.5 mR Average 1.9 mR Fiscal Year Average Level (mR) Energy Generated (MWD) 1977 1.7 702 1978 1.9 941 1979 1.5 818 1980 1.9 865

21 G. Radiation Exposures and Surveys Within the Facility A summary of radiation exposures received by facility personnel and -

experimenters is given below:

Whole Body Exposure Range (Rems) Period 7/01/79 - 6/30/80 No. of Personnel No Measurable 44 Measurable - Exposure Less than 0.1 42 0.1 - 0.25 4 0.25 - 0.5 11 0.5 - 0.75 6 0.75 - 1.0 4 1.0 - 2.0 3 TOTAL 114 Sum =ary of the results of radiation and contamination surveys from July 1979

, to June 1980:

During the 1979-1980 period, the Reactor Radiation Protection Office con-tinued to provide radiation protection services necessary for full powcr (5 megawatts) operation of the reactor. Such services (performed on a daily, weekly, or monthly schedule) include the following:

1. Collection and analysis of air samples taken within the reactor containment shell, and in the exhaust ventilation system.

2. Collection and analysis of water samples taken from the reactor cooling towers, D7 0 system, waste storage tanks, shield coolant, heat exchangers, fuel storage facility, and the primary system.

3. Performance of radiation and contamination surveys, radioactive waste collection, calibration of reactor radiation monitoring systems, and servicing of radiation survey meters. -

4. The providing of radiation protection services for control rod removal, spent-fuel element transfers, ion column removal, etc.

The results of all surveys described above have been within guide lines estab-lished for the facility.

W 22 m .. ,.

H. Radioactive Effluents The nature and amounts of radioactive effluents from the MITR during FY80 are summarized in Table H-la, b and c. .

For the activity in liquids released to the sanitary sewerage system, the amounts are given on lines - 1(a),1(b), 2(a), and 2(b) . Line 1(a) gives the totals of activities, except tritium, in liquids released. co the sani-tary sewerage system both from the vaste tanks and from the cooling towers.

For some vaste tank discharges, the Line 1(a) activities sometimes exceed 3 x 10-6 pCi/ml, usually due to activated corrosion products. In these cases, the activities measured are given on Line 1(b). In calculating con-

, centrations no credit is taken for' dilution by non-radioactive waste water from the Nuclear Engineering Building on the reactor facility site or from the remainder of the MIT Cambridge campus, since these are not routinely j

measured. The volumes of water discharged from the waste tanks and the cooling tower blowdown are measured, however, and are given on lines 2(a) and 2(b) . The total concentrations for nuclides other than tritium did not exceed 3 x 10-6 pCi/m1, when credit is taken for dilution of the waste tank i water by the measured cooling tower water, both of which discharge into the sewer at the same point.

The principal gaseous nuclide is Ar-41 from the stack. The annual average concentration as a percent of MPC (53.0%) is down slightly from last ,

year (61.3%) . The curies per unit of energy generated was also down slightly i 9.5 Ci/ MWD in FY80, compared to 10.4 Ci/ MWD in FY79.

Other gaseous ' effluents are reported in d2e balance of Table H-la and in Table H-lb. The sua of the fractions of MPC add up to approximately 0.04%.

Values are calculated from analyses made of the core purge gas (air flowing

!. across the top of the core tank and through the primary coolant storage tank at 5-6 CFM). Concentrations here are 1400 times greater than af ter dilution in the building exhaust (8500 CFM), and it is possible to detect concentra-

' tions of nuclides, such as the Kr, Xe and I reported last year. None of these have been detected since the removal of an elenent with faulty cladding

, in June 1979.

The activity in solid waste shipments are reported in Table H-1c.

-~

t a*

I t

Table li-la StnetARY OF HITR RADIOACTIVE EFFI.UENTS FISCAL YEAR 1980 g (1) 1980:

g i/ml) Unite 1979:

Dec. Feb. Har. Apr. Hay June Total Nov. Jan.

ActivtrL ni liquids released to sanitary sewerage systems: M Am Sept. Oct._

1(c) L>t al gross 6, excluding H (C1) NDA( 0.0000) NDA NDA NDA 0.000 NDA NDA NDA JA 0.000 0.000 0.000 (b) (C1) NDA 0.000 NDA NDA NDA 0.000 NDA NDA HDA NDA 0.000 0.000 0.000 Specifgcnuclidesother than

>3 IQwhereline1(a) x 10 pCi/ml (Co-60 identified) 3 a f rom waste tar.ks (C1),4 No 0.017 go No No 0.068 No No No No 0.010 0.003 0.09g 2(a)

Aserage concentration 1 x 10 -1 (x104 pC1/ml) Disch. 52 Disch. Disch. Disch. 220 Disch. Di ch. Disch. Disch 34 5.2 63.3 voluae of effluent water O) (x10 liters) 0.33 0.31 0.30 0.62 1.56 (b) 11 f rom cooling towers (C1),4 0.000 0. N 0.000 0.000 0.000 3.0M 0.002 0.002 0.002 0.002 0.002 0.002 % 0.00 1 x 10" (8) (x104pCi/ml) 0.008 0.011 0.014 0.007 0.005 0.017 0.026 0.019 0.024 0.019 0.023 0.024 0.018 Average concentration II 28.4 21.6 43.1 58.4 64.5 74.2 77.8 82.7 80.6 70.1 83.1 710 W 1ume of effluent water (x10 liters) 23.7 Activity in caseous wastes:

856 705 835 664 656 341 712 726 691 422- 567 8219 (C1) g 544

1. Ar from stack I6 -8 (x10~ pCi/ml) 1.83 2.30 2.37 2.24 2.23 2.21 2.26 2.39 2.44 1.86 1.42 1.90 2.12 47)

Average concentration 4 x 10 53% MPC 0.67 0. M 0. M 0.81 0.69 0.83 0.M 0.62 0.76 0.88 0.76 0.86 9M 2(a) 11 from stack (C1) gy 2.51 2.08 2.55 2.47 Average concentration (6) 2 x 10 (x10, pC1/ml) 2.25 2.72 2.50 2.17 2.32 2.78 2.37 2.55 2.88 0.01% HPC 0.002 0.003 0.003 0.001 0.001 0.003 0.005 0.003 0.004 0.003 0.004 0.005 0.037

1. 'CMb) 11 from coollag tower (C1),gg 2.68 2.23 2.74 1.95 3.~a 3.41 2.10 2 x 10

~

(x10 toi/ml) 1.34 1.72 2.05 0.81 0.79 2.22 Average concentration 0.01% HPC (L >)

Y?2)

-6 Na r c s_:, (1) 10CFR20. (2) NDA - No Detectable Activity, less than 1.25 x 10 Cf /mi Beta for every sample. (3) 0.000 indicates less than 0.0005 C1.

M (4) Weighted Average of individual discharges. (5) Doca not include other diluent from HIT estimated at 2.7 million gals / day. (6) Average concentrations of gaseous stack wastes include authorized dilution factor of 3000. (7) Fiscal year totals are averaged over 12 months for EM u gaseous releases. (8) Technical Specifications 3.8-1.b limits cooling tower concentration to 1 x ?O -3 pCu/ml. u w .

55iE3 b

4 a

Table ll-lb .

SUMMARY

OF MITR RADIOACTIVE EFFLUENTS FISCAL YEAR 1980 4

Activity in Caseous Waste astimates of annual releases from stack for other nuclides based on representative samples:

Average Conc.

Nuclide MPC (uCf/ml) (uci/ml)  % MPC Curles O -8 ~

1I .174 3 (a) Br 3 x 10 0.045 x 10 0.0015 80m -8 ~

11 008 (b) Br 0.01 x 10 0.002 x 10 0.02

-8 (c) Br 4 x 10 0.001 x 10"I1 0.00003 0 04 j TOTAL 0.022 9

. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ e. _ _ .-

W Table H-1c

SUMMARY

OF MITR RADIOACTIVE SOLID WASTE SilIPMENTS FISCAL YEAR 1980 Units October 1979 November 1979 February 1980 March 1980 May 1980 Total

1. Solid waste packaged Cubic 117 117 230 82.5 83.02 629.5 -

Feet

2. Total activity (irradiated compon-ents, ion exchange resins, etc.) (C1) 100.6 84 0,122 0.019 0.057 184.8 c 60 ~

Co, Cr, Fe, 65 Zn, etc.

3. (a) Dates of 5-29-80 Shipment 10-9-79 11-28-79 2-1-80 3-11-80 5 shipments (b) Disposition to Chem-Nuc1 car Chem-Nuclear Interex Interex Interex licensee for Systems Systems burial

.