ML20064K988

Responds to NRC Re Violations Noted in IE Insp Repts 50-111/82-02 & 50-297/82-01.Justification That Present Procedure Re Stack Monitor Sys Provides Capability of Early Detection of Fuel Clad Failure Submitted

ML20064K988
Person / Time
Site:	North Carolina State University
Issue date:	01/26/1983
From:	Cockrell R North Carolina State University, RALEIGH, NC
To:	Julian C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20064K957	List: ML20064K988 ML20064L006
References
NRP-RGC-83-15, NUDOCS 8302150075
Download: ML20064K988 (2)

Text

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. SCIIOOL OF ENGINEEIUNG DtranTstENT or NuctrAn Excistrarsc Nuct.rAn HracTon PROGnAM January 26, 1983 lhn 56% Z P 27fs50 NRP-RGC-83-15 Mr. Caudie Julian Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Docket No. 50-297

Dear Mr. Julian:

By letter dated 21 April 1982,

Subject:

Report Nos. 50-297/82-01 and 50-111/82-02, we were informed of the results of the PULSTAR inspection that occurred on 15 - 19 March, 1982. In the supporting section entitled " Details",

Section 13, Radiation Control (first paragraph), " .... the inspector ques-tioned whether a monthly radionuclide anaiysis should be performed to deter-mine the major radioisotopes present and their concentration .... but a more detailed analysis could provide early warning of fuel clad deterioration, experimental failure, or other anomalies."

We have studied this question and have reached the following conclu-sions:

1. As the inspector stated in his report, the Reactor Health Inysics Section is fulfilling our Technical Specifications requirements.

2. An early detection of a failure cannot be made by analysis at monthly intervals.

3. Early detection of a failure must be made by a detection system or systems operating concurrently with the reactor, or, by analytical techniques that are performed very fre-quently during reactor operation, or both.

Whenever the PULSTAR is operating, the following detection systems are functional:

1. N-16 Channel

2. Stack Gas Monitor (Required)

3. Particulate Monitor (Required)

4. Auxiliary Monitor (Back-up)

5. Filter GM Monitor (Back-up)

6. Area Monitor on the Primary System Demineralizer (not required)

The N-16 channel is a gamma sensitive ion chamber that surveys the primary water flow immediately after leaving the pool. Principally, this B302150075 830208 PDR ADOCK 05000111 PDR g

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Mr. Caudie Julian Page 2 channel is used for power level determination; however, it may yield the first indication of cladding failure, etc. (See Paragraph 4.1.5, Page 4-7, PULSTAR Operations Manual.)

Monitors Nos. 2, 3, 4 and 5, above, are in the air exhaust system from the reactor bay and, hence, would respond to any activity included in the ex-haust air; such as Ar-41, and fission products. ,

The monitor on the Primary System Demineralizer detects the radioacti-vity collected on the ior exchange resins. Any radioactive isotope (gamma emitter) will be monitored at this point.

Any one or all of these monitors, which are functioning during reactor operation, would provide earlier warning of a fuel cladding deterioration, experiment failure, or other anomaly than would a detailed spectral analysis made once a month.

The above monitor systems are under the observation of the Reactor Opera-tor who records each value in the Console Log approximately hourly.

If one or more of these monitor systems evidences an increased reading, this change is closely followed; should the increase continue, the Operator will notify the P,eactor Operations Manager (or Designated Senior Operator) and the Reactor Health Physicist. An investigation of the cause of the increased monitor reading follows immediately. As a part of this investigation, as re-quired, a detailed spectral analysis would be mode of the suspected source (s) of the increased radiation. Appropriate actions would be taken to correct or to mitigate the cause.

In view of the above, if the objective is the early detection of a poten-tial hazard, then all functioning detection systems associated with the reactor need to be observed and the readings evaluated on a regular basis. This is ac-complished and documented on PULSTAR. The operating personnel, including the Health Physics Section, are trained to spot, to report, and to investigate situ-ations that appear to be abnormal. The results of the investigation determines the action (s) to be taken, which may vary from correcting the situation to a reactor shutdown.

Since the inspection in March, 1982, the reactor water, taken after a minirnum of one hour operation, has been analyzed for radioisotopic content on a monthly basis. The analysis shall be continued.

Since we believe that our present procedure provides us with the capa-bility of early detection of fuel clad failure that is more than adequate to meet technical specifications, we prefer to continue with established pro-cedures and not implement a new procedure which may be interesting but is not likely to give us an earlier warning of fuel clad failure.

We respectively request your concurrence with this position in the light of the information presented in this letter.

Ver truly yours, RGC:1pe Robert G. Cockrell h

cc: Pau T . sky Director, Nuclear Reactor Program Mr. R. D. Cross