ML20207M532

Forwards Request for Addl Info Re 861003 Proposal to Convert Reactor Core to Low Enriched U Fuel.Requests Response within 30 Days of Ltr Date

ML20207M532
Person / Time
Site:	Rensselaer Polytechnic Institute
Issue date:	01/06/1987
From:	Dosa J Office of Nuclear Reactor Regulation
To:	Harris D RENSSELAER POLYTECHNIC INSTITUTE, TROY, NY
References
NUDOCS 8701130212
Download: ML20207M532 (6)

Text

January 6, 1987 Docket No. 50-225 Dr. Donald R. Harris, Director Critical Facility Department of Nuclear Engineering and Science Rensselaer Polytechnic Institute Troy, New York 12181

Dear Dr. Harris:

SUBJE'CT: REQUEST FOR ADDITIONAL INFORMATION - RENSSELAER POLYTECHNIC INSTITUTE 4 In our review of documentation that has been submitted in support of your proposal to convert your reactor core to use low enriched uranium (LEU) fuel, dated October 3, 1986, some questions have arisen for which we require answers. Please provide written responses to the enclosed questions no later than 30 days from the date of this letter. Following receipt of this information we will continue our review.

If you have any questions concerning this request, please contact me at (301) 492-8529.

The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, Original signed by John J. Dosa, Project Manager Standardization and Special Projects Directorate Division of PWR Licensing-B Office of Nuclear Reactor Regulation

Enclosure:

DISTRIBUTION:

As stated / Docket- File 7

" NRC' PDR """

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% ,,,,,* January 6, 1987 Docket No. 50-225 Dr. Donald R. Harris, Director Critical Facility Department of Nuclear Engineering and Science Rensselaer Polytechnic Institute Troy, New York 12181

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION - RENSSELAER POLYTECHNIC INSTITUTE In our review of documentation that has been submitted in support of your proposal to convert your reactor core to use low enriched uranium (LEU) fuel, dated October 3, 1986, some questions have arisen for which we require answers. Please provide written responses to the enclosed questions no later than 30 days from the date of this letter. Following receipt of this information we will continue our review.

If you have any questions concerning this request, please contact me at (301)492-8529.

The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely,

. A ohn J. Dosa, Project Manager Standardization and Special Projects Directorate Division of PWR Licensing-B Office of Nuclear Reactor Regulation

Enclosure:

As stated cc w/ enclosure:

See next page

.- Rensselaer Polytechnic Institute Docket No. 50-225 cc: Mayor of the City of Schenectady Schenectady, New York 12305 New York State Department of Environmental Conservation ATTN: Director, Office of Environmental Analysis Albany, New York 12223 Director, Bureau of Environmental Protection New York State Department of Environmental Conservation ,

Albany, New York 12237 Mr. Francisco Rodriguez Vera.

Department of Nuclear Engineering and Science Rensselaer Polytechnic Institute Troy, New York 12181 Director, Technical Development Programs State of New York Energy Office Agency Building 2 Empire State Plaza Albany, New York 12223 New York City Department of Health Public Health Library 125 Worth Street New York, New York 10013 Attorney General Department of Law State Capitol Albany, New York 12224

v Enclosure Request for Additional Information Rensselaer Polytechnic Institute .

Docket No. 50-225 HEU/ LEU Core Conversion Proposal

1. Proposed changes in security exclusion 2 ones are not considered to be relevant to core conversions and will not be reviewed by NRC with your proposal. These proposed changes should be reviewed and processed according to 10 CFR 50.54(p) or 10 CFR 50.90, whichever is appropriate.

2. Is the multiplication factor referred to in calculations for the fuel storage vault k infinite or k effective?

3. Can the radial positions of the control rods be altered, if necessary, to assure that they are always adjacent to the outside row of fuel' pins?

4. The effective neutron lifetime given in Table 5.1 for the RPI LEU core appears to be very short, especially for a thermally optimized lattice. Please explain this.

5. In the analysis of the MHA (maximum hypothetical accident) for your facility it is stated that a pre-accident power level of 200 watts is assumed based upon the Technical Specifications power level limit of 100 watts and incorporates a factor of two to account for the cumulative uncertainties associated with instrument calibration.

Explain what these cumulative uncertainties are and describe the precautions taken by the operating staff to minimize these uncertainties during normal operation.

6. Linear Power Channels I and 2 are assumed to indicate a value of 10%

on the highest selectable scale (100 watts indicated with a factor of 2 uncertainty) at the onset of the analyzed MHA. It is then stated that the power level must rise to 1800 watts before the Linear Power Channel Scram is activated. This does not correspond to the basit used for Technical Specification 2.2 which states that 90% of the highest scale for the linear power channels (the scram setpoint) corresponds to a power level of 135 watts. Explain and correct this discrepancy.

7. All parameters used to calculate the consequences of the MHA utilize approximately the same level of conservatism, except the value of the proposed reactivity insertion. Reevaluate the MHA with all parameters involved utilizing approximately the same level of conservatism (the same percentage of the Technical Specifications limits).

8. What are the units of reactivity used in Table 5.2 of your proposal?

You indicate in this table that the values for most of the parameters given for Core B are more restrictive than for Core A. Does this mean the values are more conservative? Provide expected values of the parameters for Core A. Review and correct all values listed in the

" Technical Specification" column against those values given in the proposed Technical Specifications.

9. Explain why normal operations can be performed safely with Core B when a positive temperature coefficient of reactivity exists.

10. What is the calculated value of the Doppler coefficient?

11. What are the expected ir.dividual and total control rod worths with the LEU core?

12. What is the significance of two B 10 absorber sections in a control rod, versus one section?

13. What are the requirements for the BF3source range counters during startup testing?

14. Will the water height adjustment capability be utilized during startup testing?

15. Please'be aware that the results of the startup tests should be kept on file for the life of the facility. These results must be submitted as a written report to the NRC within 60 days of the startup program's completion. The contents of the report will be reviewed and approved by the NRC before normal operations can be implemented.

16. What is the correct date for Reference No. 8 on page 24 of your proposal? Please submit copies of Reference Nos. 2, 4 and 5.

17. Discuss the differences in the types of absorber sections listed in the Technical Specifications definition of control rod assembly and their different effects on reactivity. The definition is not consistent with Section 5.4.4 of the Technical Specifications nor Section 4.4 of the Safety Analysis Report. Please clarify this.

18. Definition 1.Q.6 of the Technical Specifications uses a value of $0.70 for the reportability criterion for an unanticipated change in reactivity. Why is this value higher than the value of $0.60 analyzed in the proposal as the MHA?

19. All references to fuel elements throughout the Technical Specifications should be updated to the use of fuel pins.

20. Provide a more detailed explanation of the use of energy deposition in the fuel as the basis for the safety limit for your critical facility. Show all calculations and list the references used.

21. Why should the integrated thermal power not exceed 200 KWh per year for the LEU core as given in Technical Specification 3.1.107

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22. Proposed Technical Specifications 3.2.1 and 3.2.2 are less conservative than your current Technical Specifications limits.

Provide an explanation for this with emphasis on safety considerations.

23. In the bases for Technical Specifications 3.4.8 and 3.4.9, provide the correct references where 10 CFR 105(1) and 10 CFR 106 are currently listed.

24. Revise proposed Technical Specification 5.6 to be consistent with your recently amended Technical Specification 5.7.

25. In Technical Specification 5.6.1 the pin worth value of $0.72 is inconsistent with the maximum single pin worth of $0.20 allowed in Specification 3.1.1. Please explain this.

26. Proposed changes to Section 6 of your Technical Specifications are not considered to be relevant to your core conversion and will not be reviewed by NRC with your proposal. The proposed changes should be submitted as an amendment according to 10 CFR 50.90.

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