IR 05000128/1986001

Reactive Insp Rept 50-128/86-01 on 860505.Violation Noted: Failure to Measure Reactivity Worth of Experiment Before Reactor Operation & to Rept Reactivity Greater than One Dollar Associated w/860310 Event

ML20198A080
Person / Time
Site:	05000128
Issue date:	05/09/1986
From:	Constable G, Murphy M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20198A071	List: IR 05000128/1986001 ML20198A066
References
50-128-86-01, 50-128-86-1, NUDOCS 8605200323
Download: ML20198A080 (7)

Text

{{#Wiki_filter:r . . APPENDIX U. S. NUCLEAR REGULATORY COMMISSION

REGION IV

NRC Inspection Report: 50-128/86-01 License: R-83 Docket: 50-128 Licensee: Texas A&M University (TAMU) Facility Name: Texas A&M TRIGA (1 MW) Inspection At: College Station, Texas Inspection Conducted: May 5, 1986 -

4 Inspectors: M. E. Murpfiy, Rd' acto # Inspector, Project Date' / Section B, Reactor Projects Branch _. _ r/" f 6 _G. L.CvudaliTe, Chief, Projects Section C, Dath ' Reactor Projects Branch -. - r[[1lr[ Approved: ' Gn. Ctmsta5Te';-GhTer,~ Project Section C, Datre Reactor Projects Branch Inspection Summary Inspection Conducted May 5, 1986 (Report 50-128/86-01) Area Inspected: Reactive, unannounced inspection of uncontrolled reactivity excursion event caused by movement of experiment.

Results: Within the area inspected, three apparent violations were identified involving the movement of a non-secured experiment with a reactivity worth of greater than one dollar, failure to estimate or to measure the reactivity worth of an experiment before reactor operation and a failure to report an unanticipated or uncontrolled change in reactivity greater than one dollar associated with the March 10, 1986 event.

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DETAILS 1.

Persons Contacted

• D. E. Feltz, Director, Nuclear Science Center (NSC)

G. Stasny, Senior Reactor Operator

• J. Krohn, Manager, Reactor Operations (SR0)

F. Stag, Reactor Operator

• Indicates those present at the exit interview.

In addition to the above personnel, the NRC inspectors held discussions with various operations and technical support members of the reactor staff.

2.

General On May 2, 1986, Texas A&M University (TRIGA) reported to NRC Region IV that an apparent violation of technical specifications had occurred on May 1, 1986, when an experiment was moved causing a power excursion that scrammed the reactor.

The NRC staff, in a phone conversation with Mr. D. E. Feltz of Texas A&M University, confirmed the details of the event and satisfied the staff that this event did not pose a direct threat to the facility, the operators, or the health and safety of the public.

On May 5, 1986, the NRC conducted an inspection into the circumstances of the event to determine the root cause, evaluate licensee corrective actions, and to determine what enforcement action, if any, would be appropriate.

The NRC inspectors concluded that several NRC requirements had apparently been violated, as discussed below, and that the actions of the Nuclear Science Center (NSC) staff were deficient.

Apparent violations of NRC requirements are summarized in paragraph 6 below.

3.

Sequence of Events April 30, 1986 Wednesday 9:27 a.m.

The TRIGA (1 MW) facility was to operated at full power 3:45 p.m.

5:00 p.m.

An SR0 (not the duty SRO) installed experiment 86-123 in position B-5 for overnight gamma irradiation. This action was logged in the consents section of the operators log.

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May 1, 1986 Thursday 8:15 a.m.

The prestartup check list was signed off as complete by the R0 and SR0 on duty.

8:30 a.m.

Reactor core was moved to the stall next to the beam port 4 reflector.

9:16 a.m.

Began reactor startup.

9:30 a.m.

Reactor at 1 MW and control rods noted to be abnormally high.

Experiment 86-123 observed in reactor.

9:35 a.m.- Reactor power reduced to 50% to remove experiment 86-123.

9:39 a.m.

Reactor scram (over power - safety amplifier) occurred due to removing experiment 86-123 from B-5 position.

9:42 a.m.

Reactor restarted to continue irradiation of other experiments.

Apparent violations of NRC requirements are summarized in paragraph 6 below.

4.

The Experiment Experiment 86-123, referred to as the Marques /Krohn experiment, involved the gamma irradiation of topaz to study the changes in color. The experi-ment was intended to be in the reactor only while the reactor was shut down.

The topaz was placed in a boron lined rotisserie unit to minimize the efect of source and delayed neutrons. This rotisserie unit was maneuvered into reactor core location B-5.

In this position the experiment was surrounded on three sides by adjacent fuel bundles. The reactivity of this experimental device had not been previously measured in this core location because there was no intention of operating the reactor with this experiment in the core.

-In previous experiments this boron lined rotisserie device (referred to as " Boron Short") had been irradiated in the A-3 and A-5 (core face) positions.

In those experiments the rotisserie reactivity was measured and determined to be approximately $0.18.

The reactivity of the experiment in the B-5 position was evaluated after the reactor scram on May 1,1986, to be worth approximately $1.08.

Several apparent violations of NRC requirements occurred in connection with this event and are summarized in paragraph 6 belo. .< .

5.

Interviews a.

Facility Director The Facility Director learned of-the May 1,1986, event after the reactor scram had occurred. After his preliminary review, he concluded that: (1) The event was caused by operator error and a failure to follow procedures.

(2) The event was isolated and of low safety significance.

(3) The operators had been caught unaware of the worth of the experiment (entrapped) due to a lack of experience in handling this experiment in this location.

(4) Additional training of operators appeared to be needed.

(5) No formal admonishment of the individuals involved was warranted.

(6) In the future it was planned that reactor power would be dropped to less than 30% power to remove experiments with a worth greater than $0.20.

The Facility Director stated that previcus experience in moving the boron rotisserie unit away from the face of the reactor had indicated a reactivity worth of $0.13 - $0.15, and it was known that the experiment could be safely moved while the reactor was cperating. The Facility Director stated that no period scram (3 sec) had occurred during the event indicating that the power excursion was mild due to the strong power coefficent of reactivity and the ability of the TRIGA reactor core to handle transients.

The Facility Director stated that the usual practice was that an experimenter would not have operations responsibility for their own experiments.

b.

The Experiment Installer The individual who installed the experiment in the reactor is the NSC Manager of Reactor Operations and Technical Services and is a licensed SRO. He is also one of the experimenter (s) of record for this experiment.

This individual described his actions in installing the experiment and in logging the installation in the comments section of the reactor 109 He also left the following note in the shift change log: " Marques 86-123 in B-5."

He acknowledged that he did not move the " Request For Irradiation" form from the "to be irradiated" to the "in the reactor"

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basket, which is usually checked by an operator prior to startup.

Nor did he indicate in the " Experiments in core at shutdown" or " Experiments in core at startup" section of the log that experiment 86-123 had been inserted in the reactor.

He did not expect the reactor to be operated Thursday morning (May 1, 1986) and was not in the control room during the first reactor startup.

After the reactor scram, he signed the management review section of the " Recovery from Unscheduled Scram" form.

c.

Duty Senior Reactor Operator This individual was on duty both April 30 and May 1, 1986. He signed the pre-startup checklist at 8:15 a.m. May 1,1986, confirming acceptance that the checks had been properly completed. He acknowledged that he had not noticed the note in the shift change log indicating that experiment 86-123 had been installed in B-5 nor did he observe the experiment in the reactor.

When informed of the unusually high control rod position, he quickly saw that the experiment was still in the reactor. Based on previous experience with removing experiments from the face of the reactor he ordered reactor power to be reduced to 50% and had another SR0 remove the experiment from position B-5.

Removal of the experiment subsequently caused the reactor to trip on high power.

After the reactor scram, which occurred at approximately 9:39 a.m., he reviewed the circumstances of the event, concluded that simple human error was involved and signed the " Recovery from Unscheduled Scram" form. The subsequent reactor startup began at approximately 9:42 a.m.

The NRC inspectors concluded that the duty SR0 was not aware that a violation of technical specifications had occurred prior to his authorizing reactor startup.

d.

The Reactor Operator The reactor operator (received license in February 1986) operated and subsequently shut down the reactor on the afternoon of April 30, 1986.

He was not aware that Experiment 86-123 had been installed in the reactor after he had shut down the reactor. The reactor operator does not normally review the shift change 109 This same individual was on duty the morning of May 1, 1986. He completed the pre-startup checklist and started up the reactor at 9:16 a.m. May 1, 1986. During his visual inspection of the reactor prior to startup, he did not notice the experiment installed in B-5, and he checked off the " pre-startup checklist" indicating that " Experiments agree with 109."

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During the reactor startup, the operator noticed that the control rods were withdrawn further than expected and notified the duty SR0.

6.

Conclusions During the review of this event, the NRC inspectors requested a summary of previous reactor scrams caused by movement of experiments.

No reactor scrams were caused by movement of experiments durin 10, 1986, (log book 90, page 182)g 1983, 1984, or 1985; however, on March a reactor scram occurred due to the removal of the boron rotisserie (Experiment 86-123) from the B-5 position. During the NRC review of the " recovery from unscheduled scram" form, the NRC inspectors observed that the scram (3 sec period) occurred from about 30 watts. The corrective actions "... to insure safe and proper operation" noted that "In the future the rotiss (sic) will be removed prior to S/U (sic) or with the reactor on a negative period." The review by management was conducted on March 13, 1986, and the statement was added "Above procedure will prevent future scrams."

During the May 1,1986, event, neither of these actions to prevent recurrence were complied with. The same SR0 was on duty during both events.

In addition, the NRC inspectors observed that from information on the form, which was filled out in March 1986, the reactivity of the Experiment 86-123 could have been calculated and that the calculation would have indicated that the worth of the experiment was in excess of $1.00. The movement of this experiment on March 10, 1986, and again on May 1, 1986, is an apparent violation of Technical Specification 3.6.1, which requires that (a) non-secured experiments shall have reactivity worth less than one dollar, and Technical Specification 4.6, which requires that (c) the reactivity worth of an experiment shall be estimated or measured, as appropriate, before reactor operation with said experiment, and in the case of the March 10, 1986, event, the failure to report is an apparent violation of Technical Specification 6.6.2, which requires that: reports shall be made to the NRC Region IV, Office of Inspection and Enforcement as follows: there shall be a report not later than the following working day by telephone and confirmed in writing by telegraph or similar conveyance to be followed by a written report that describes the circumstances of the event within 14 days of any of the following: Any reportable occurrences as defined in Section 1.28 of these specification \\ ....

l ' Reportable Occurrence - A reportable occurrence is any of the following which occurs during reactor operation: Operation in violation of limiting conditions for operation established in the technical specifications.

An unanticipated or uncontrolled change in reactivity greater than one dollar.

The root cause of the May 1,1986, event appears to be: (1) A lack of discipline in comunications, failure to follow procedures, and inadequate filling out of logs and records.

(2) A failure to take adequate corrective action in connection with the March 10, 1986, event that was essentially identical.

(3) Inadequate knowledge of reactivity effects of experiments.

The NRC staff has concluded that enough information existed that the May 1, 1986, event and related violations of NRC requirements could have been avoided if the individuals involved had operated the facility with the appropriate discipline and attention to detail normally expected of licensed operators and senior reactor operators.

7.

Exit Interview The inspection scope and findings were summarized on May 5,1986, with those persons indicated in paragraph 1 above. The licensee acknowledged the NRC inspectors' findings, and committed to make certain corrective actions outlined in a letter to you dated May 7, 1986 (CAL 86-05). The licensee did not identify as proprietary any of the material provided to or reviewed by the NRC inspectors during this inspection. }}