ML20069E514

Forwards Natural Environ Radioactivity Survey for Period Sept 1981 - Aug 1982

ML20069E514
Person / Time
Site:	05000187
Issue date:	03/14/1983
From:	Avant D NORTHROP CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20069E516	List: ML20069E514 ML20069E528
References
R327-83-45, NUDOCS 8303220083
Download: ML20069E514 (5)

Text

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Ip r: ply rsfer g_47 to R327-83-45 NORTHROP March 14, 1983 U.S. Nuclear Regulatory Commission Region V Office of Inspection and Enforcement 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Attention:

Director, Office of Inspection and Enforcement

Reference:

(a) Technical Specifications for the Northrop Corporation TRIGA Mark F Reactor, dated 18 February 1971 l

Enclosure:

(1) Northrop Research and Technology Center,

" Natural Environmental Radioactivity Survey 1

for the period of September 1981 through August 1982" i

Gentlemen:

The following information is submitted, pursuant to Section H.7.e.

of reference (a):

1.

Administrative and Personnel l

l In July,1982, Mr. David Wood joined the reactor staff, and is l

presently a reactor operator trainee.

The immediate administration of the reactor remained unchanged during the year, but in October,1982 Dr. Steve Lukasic succeeded Dr. William Chalmers as Vice President and General Manager of the Northrop Research and Technology Center.

2.

Experiments During the calendar year,125 experiments were performed at the Northrop Reactor. The following is a summary of the types and locations of the experiments:

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PDR Northeop Corporation Northrop Rese3rch and Technology Center e

One Research Park, Pahs Verdes Peransula Cahfornia 90274 Telephone (213) 377-4811

R327-83-45 Page 2 a)

Types of Experiments humber of Experiments

1) Radiation Effects 107 11)

Isotope Production 4

iii) Miscellaneous (dosimetry 14 detector calibration, etc.)

b)

Location of Experiments Number of Experiments i) Dry Exposure Room 119 ii)

In-Core 5

iii)

Beam Ports 1

iv)

In-Pool 0

v) Pneumatic Tubes 0

3.

Operating Data Operating data for the reactor during 1982 is as follows:

a)

Time Critical 80.173 Hours b)

Integrated Power 23.250 MwH c)

Number of Pulses 51 d)

Worth of Pulses

$137.50 e)

Times Taken Critical 219 4.

Facility Changes The only facility changes made during 1982 were related to the

" Phase II" upgrading (modification) of reactor instrumentation:

a)

Due to incompatability with the new instrumentation, the "new", recently installed regulating rod drive motor was removed and replaced with the older reg. rod drive motor; b)

The range switch, flux controller, NV/NVT, recorder, and related circuits were modified and/or replaced, according to the manufacturers instructions; 5.

Inadvertent Scrams During the year there were seven(7) inadvertent scrams:

a)

A drop in the incoming electrical power caused a loss-of-power scram. The power supply was checked, some vacuum tubes replaced, and the system returned to operation.

b)

A period meter scram occurred when its needle stuck momentarily, then overshot after it became free. The meter was checked and found to operate properly.

c)

Sensitive settings in the recorder scram circuit of the new flux controller module caused one scram.

These settings were adjusted and rechecked prior to resumption of operation.

d)

While making a 1 megawatt run, the ambient temperature and ganna buildup caused enough of an increase in the percent power meter reading to scram the reactor. This meter was checked, and found to operate normally.

R327-83-45 Page 3 e)

During one run, the regulating rod magnet power lamp burned out, interrupting power to the magnet, and allowing the regulating rod to drop back into the core.

The bulb was replaced, checked, and the operation resumed.

It should be noted that this involved only the regulating rod, and did not scram the other control rods.

f)

Two consecutive recorder scrams occurred while conducting a reactor run to check the setting of a compensated ionization chamber. They both were caused by electrical transients:

the first, when changing the linear recorder switch from the "1 Mw" to the " Calibrate" position; and the second, when later switching out of the " Calibrate" position.

The switch was checked and appeared to be functioning properly.

6.

Maintenance The more significant maintenance performed during the year consisted of:

a)

Inspection and calioration of the control rods; b)

Inspection and measurement of the fuel elements; c)

Replacing the filters in the water treatment loop of the primary coolant system; d)

Replacing the vacuum tubes in the regulated power supply which may have been affected by a dip in the incoming electrical power and the subsequent reactor scram; e)

Substitution of temporary power supplies for the "resid"nt" power supply in the log channel circuit, after the latter was damaged by an electrical short; I

l f)

Replacing the op-amp in the new range switch circuit, after the former was damaged by an electrical transient; i

l g)

Replacing the air pump motor on the stack (RM1) monitor, i

a couple of times and then, finally, replacing the motor i

and the air pump, after the problem with the short life j

of the motors was discovered to be caused by a defect in the pump itself.

l 7.

Experiments l

Only routine experiments were performed during the year.

R327-83-45 Page 4 8.

Radioactive Effluent A summary of the. radioactive effluent released during 1982 is as follows:

a)

Effluent released to the air:

1) Monthly averages of Argon-41 (in p Ci/ml)

January none released February 2.73 x 10-10

-10 March 1.97 x 10 April 7.25 x 10-10

-II May 1.12 x 10 June 7.49 x 10-10

-U July 5.94 x 10

-9 August 1.15 x 10

-10 September 1.80 x 10

-10 October 6.66 x 10

-10 November 4.59 x 10

-10 December 2.41 x 10

2) Total activity of Argon-41 released to the air was 3.805 curies.

5)

There was no liquid waste released during 1982.

9.

Environmental Survey A description of the environmental survey program performed outside the facility is attached as enclosure 1.

10.

Personnel Radiation Exposures Personnel radiation exposures during 1982 are summarized as follows:

a)

Radiation exposures to Reactor and Health Physics Personnel averaged 6.2 milliroentgens per individual per week.

b)

Radiation exposures to Reactor visitors averaged 0.77 milliroentgens per individual per day. This average does not include exposures to the visitors from one customer whose experiments required higher than average exposures. Treated separately this latter group averaged 8.01 milliroentgens per visitor per day.

If this group is included in the overall total, the radiation exposures to all reactor visitors would average 2.18 milliroentgens per day.

c)

No personnel over-exposure occurred during this period of Reactor operation.

R327-83-45 Page 5 11.

Reactor Surveys a)

Significant radiation levels documented in the following facility areas:

1) The shielded door to the dry exposure room is monitored every time it is opened. There were 196 such openings with an average radiation level of 11.7 milliroentgens per hour per opening, and a maximum level for one opening of 100 milliroentgens per hour.

ii) The maximum recorded level in a restricted area (where visitors are normally not allowed without staff supervision) was 2.25 roentgens per hour. This occurred on the Reactor deck during a transfer of an in-core experiment.

Non-staff, non-essential personnel are not allowed in the vicinity during such operations.

b).

Radioactive contamination surveys within the Reactor were made throughout the year.

1)

In the general area (where Reactor visitors have free access) the maximum contar.ination level found was 71 disintegrations per minute (a, 8, y) on a work table used in the Hot Cell in loading calibrators. The table was decontaminated.

ii) Maximum contamination levels found in restricted areas were 239 disintegrations per minute (a, 8, y) on a pair of Hot Cell manipulator fingers and 153 disintegrations per minute (a, 8, y) on a Reactor deck table used during the transfer of in-core experiments. The fingers and l

table were decontaminated.

t i

Very truly yours, f

fd aniel W. Avant, Executive Secretary Corporate Radiation Committee l

DWA:rb Encl.

cc:

Director:of~ Nuclear Reactor Regulation

,2, copies l

U.S. Nuclear Regulatory Commission Washington, D. C.

20555 Director of Inspection & Enforcement

- 40 copies c/o Distribution Services Branch DDC-ACM Washington, D. C.

20055 l

l l

I m.'e NORTHROP Research and Technology Center