ML19309C221
| ML19309C221 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos Nuclear Center |
| Issue date: | 02/29/1980 |
| From: | Gilliland D GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19309C216 | List: |
| References | |
| NUDOCS 8004080313 | |
| Download: ML19309C221 (5) | |
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GENERAL ELECTRIC NUCLEAR TEST REACTOR ANNUAL REPORT NO. 20 License R-33 Docket 50-73 8004080 3/3
o.
GENERAL ELECTRIC NUCLEAR TEST REACTOR ANNUAL REPORT NO. 20 I.
INTRODUCTION This report summarizes the operation, changes, tests, and experiments at the Nuclear Test Reactor (NTR) authorized pursuant to License R-33 and 10CFR50, Section 50.59 for the period January 1 through December 31, 1979 II.
GENERAL A.
The reactor was operated at or above critical for 885.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
A total of 279 startups were made while a total of 5 scrams occurred.
B.
The average radiation exposure to facility personnel was 0.8 Rem in 1979 C.
There were two occurrences at the NTR which required reports to the NRC during 1979 D.
A timely application was submitted to the NRC requesting the renewal of the R-33 license.
III. ORGANIZATION There were no changes in the organizational structure at the NTR during 1979 IV.
CHANGES, TESTS, AND EXPERIMENTS AP/ ROVED BY THE MANAGER, REACTOR IRRADIATIONS A.
Changes Pursuant to 10CFR50.59(a) the Manager, Reactor Irradiations, authorized nine changes during the 1979 calendar year. The changes are briefly described below.
1.
Building Air Compressor Alarms Description High-temperature and low-pressure alarms were installed on the building air compressor.
Safety Analysis This change provided the capability to assure that air supplied to air line respirators is of acceptable quality.
2.
Secondary Cooling Water System Modification Description A valve, flow totalizer, and pressure indicator were removed. A check valve was added.
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Safety Analysis The items that were removed were no longer used or required.
Removal does not affect the safety of the system. Addition of the check valve provides a second isolation valve between the contaminated primary water system and the potable water.
3 Fuel Storage Real Description The fuel storage reel was removed from the fbel storage tank.
Safety Analysis Fuel elements will not be stored in the fuel storage tank or at any other location at the NTR.
4 Safety Rod Electromagnet Description The method by which the magnet coil was held into its assembly was changed.
An interference fit is now used instead of a potting compound.
Safety Analysis Safety was not lessened since the new method for securing the magnet was determined to be at least as good as the old method.
S.
South cell Entrance Alarm System Description This change authorized the separation of the South cell electric eye alarm from the South cell high radiation alarm.
Safety Analysis Separating the alarms provides an individual alarm for each system so that they can be distinguished.
6.
Primary Water Flow Orifice Modification Description A vent hole was drilled in the orifice to allow entrapped air to vent through the orifice section.
Safety Analysis The addition of the vent hole decreased the orifice delta pressure by less than 1% at the normal flow rate. The system was recalibrated and appropriate changes were made. The change resulted in no safety implications.
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7.
Primary Water System Flange Replacement Description A threaded flange was replaced so that it would more properly align with the bolt holes on a check valve in the system.
Safety Analysis The replacement flange provided better alignment with the check valve bolt holes, thus the system integrity was increased.
8.
Primary Water System Delta Temperature Alarm Description The alarm unit on the primary water system reactor core differential temperature thermopile was removed.
Safety Analysis Removal of the alarm does not compromise the safety of the reactor'. The alarm served only as a warning of high temperature and was redundant with the in-line high-temperature alarm and high-temperature scram.
9.
Fuel Loading Chute Plug Description A vacuum pump was attached to the fuel loading chute plug vent line to allow drying of the graphite contained in the plug.
Safety Analysis The rate at which reactivity is recovered by the removal of the water will have no adverse effect on reactor operation.
B.
Tests Pursuant to 10CFR50.50(a) the Manager, Reactor Irradiations, authorized three tests during the 1979 calendar year. The tests are briefly described below.
1.
R/drogen Purge During Neutron Radiography Description A specimen being Neutron Radiographed was purged with a very low flow of hydrogen.
Safety Analysis The safety of the reactor was not affected.
Appropriate precautions were taken to minimize all other risks.
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c 2.
Spare Primary Water Flow Recorder Test Description A second recorder was attached to the primary coolant flow transmitter output circuit. This test was to determine whether occasional erratic flow indication was recorder or transmitter oriented.
Safety Analysis The safety of the reactor was not lessened since the second recorder had no effect.
3 Nuclear Instrumentation Time Response Measurements Description The response time due to the initiation of a scram signal was measured for the picoammeters and the Log N.
Safety Analysis The test verified that the response time was as required. This test was subsequently added to the scheduled preventive maintenance tests.
C.
Experiments No types of experiments were perfbrmed which are different from those already described in Section 7.0 of the Summary Safeguards Report fbr the General Electric Nuclear Test Reactor, APED-4444-A or as specified in annual reports submitted since the submittal of APED-4444-A. A total of 370 experiments were reviewed, approved, and perfbrmed.
V.
CONCLUSION The over-all operating experience of the Nuclear Test Reactor reflects another year of safe, efficient operation. We anticipate the operation of the reactor will continue on this basis.
GENERAL ELECTRIC COMPANY Irradiation Processing Operation By D. L. Gilliland, Manager Reactor Operations 4