ML20058P491
| ML20058P491 | |
| Person / Time | |
|---|---|
| Site: | Pennsylvania State University |
| Issue date: | 10/19/1993 |
| From: | Voth M PENNSYLVANIA STATE UNIV., UNIVERSITY PARK, PA |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9310250048 | |
| Download: ML20058P491 (2) | |
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PENNSTATE r=0.
College of Engineering nrea/cate Nucles r Reactor Building Radiatum Science and Enginecrmg Center '.ne Pennsyhania state Unisenity University Park, PA 16802-2301 October 19,1993 !
US Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 ;
Re: Report of Technical Specification Design Featme Error l Penn State Breazeale Reactor (PSBR)
License Number R-2, Docket Number 50-005 1 The following repon is a description, analysis and action plan concerning the discovery that -!
a design feature in the PSBR Technical Specifications is incorrect. While we do not find -
this to be a required reportable event, an information report is being provided.
Reactor Status: r The reactor was secured from the time of the discovery until the PSBR Director, Dr. :
Marcus Voth discussed it with Mr. Marvin Mendonca and Mr. Stephen Holmes, Project l Manager and Principle Inspector, respectively, of the Nuclear Regulatory Commission, llackground: l The PSBR Technical Specifications, facility operating license R-2, Docket No.50-005, -
3 states in 5.5.a. that " .. The minimum free volume in the reactor bay shall be 2500 m ." In the afternoon of October 12,1993 a staff member verifying design data measured the free i volume of the reactor bay and discovered that it was possibly less than 2500 m3 . It was verified the morning of October 13 that the free volume was 2380 m3 , before correcting for ,
the volume of equipment storage cabinets, the upper part of the reactor pool, etc. That correction could amount to as much as 100 m3. Even though the error is less than 10% the specification constitutes a requirement and the PSBR facility does not meet that ;
requirement.
Analysis:
The PSBR Technical Specifications that were issued by the AEC on December 30,1965 (conversion to a TRIGA core) stated that "The minimum free volume in the reactor bay -;
shall be 70,000 ft3." This _would convert to 1984 m3 . During the license renewal in 1986.
the specification was increased 10 2500 m3 . It is not clear how these numbers were +
derived. Documents suggest that the 1965 number was known to be conservative because .
it only included the nominal volume of the high bay area; the low bay of a nominal volume of 500 m 3was not included. The 1986 number was presumably the sum of the two nominal volumes.
The value of 2500 m 3is used in the SAR, chapter 9 section E, to detennine the l radionuclide concentration in the reactor bay and the concentration in the unrestricted area
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' during a maximum hypothetical accident (a fuel element rupture in an air cooled com). This accident is defined in the SAR as " ..a postulated accident with potential consequences 1 greater than those from any event that can be mechanistically postulated." The assumptions ,
are that the reactor is operated for 70 consecutive full power hours, the pool is drained t immediately, a fuel element is mechanically ruptured in air and the fission products are l dispersed throughout the air volume. This is not a plausible fuel handling accident because j fuelis not handled in this manner. ?
The SAR contains no uncertainty analysis of the calculations and assumptions used to ;
analyze this particular postulated accident. A 10% error in the free volume is not ;
inconsistent with the expected uncertainty of the other values and assumptions usedin the l S AR. In addition, a correction based on this particular error does not significantly change 1 the conclusions of the analysis. Therefore, the fact that we do not meet this specification and cannot meet this specification without adding volume to the existing building has no i significant consequence.
Immediate Corrective Action: ;
As soon as the discovery of the error was made it was determined that the reactor should ;)
remain secured until the NRC was informed and a resolution agreed upon.
At 0830, October 13,1993, during a conference call among Dr. Voth, Mr. Mendonca and .
Mr. Holmes, the following resolution was agreed upon:
- 1. Mr. Mendonca and Mr. Holmes will log the conversation and confirm that their management concurs with this resolution.
- 2. PSBR will remove any restrictions on reactor operation. q
- 3. PSBR will submit a written report within a week to make a qualitative assessment of the impact that the error has on the SAR (This report fulfills tnis commitment.)
- 4. PSBR will request a Technical Specification change with SAR revisions later this year along with other changes currently being prepared.~ ,
l Final Corrective Action:
PSBR will request an amendment to the Technical Specifications with the appropriate SAR l
changes.
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Sincerely, hkhs Marcus H. Voth Associate Professor, Nuclear Engineering Director, Radiation Science & Engineering Center MilV/ld14169 cc: US NRC Region 1 Administrator ;
S. W. Ilolmes M. Mendonca
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