ML19322D251
| ML19322D251 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/11/1979 |
| From: | Parler W NRC - NRC THREE MILE ISLAND TASK FORCE |
| To: | Deyoung R NRC - NRC THREE MILE ISLAND TASK FORCE |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8002100093 | |
| Download: ML19322D251 (3) | |
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June 11, 1979 9 o....
In reply refer to:
NTFTM 790611-01 MEMORNIDUM FOR:
Richard C. DeYoung, Interim Deputy Director NRC/TMI Special Inquiry Group FROM:
William Parler, Leader, Task Group 1
SUBJECT:
POTENTIALLY SIGNIFICANT HISTORICAL INFORMATION FOR THE INQUIRY As you requested, there is attached a preliminary list of historical items which may potentially be of significance in the inquiry.
This does not imply any of them will eventually be shown to have a causal relationship to the accident.
They appear to be promising leads to examine how the licensing and regulatory system worked.
I emphasize that these are preliminary identifications. We are still searching for others and are only beginning to attempt to trace how these items were handled by the regulatory organization.
This, will not be an easy task.
As I am aware, no similar effort has ever been made, avas/
Williar. Parler, Leader Task Group 1 Enclosure 0 0 0210 0 C>} J
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ENCLOSURE 1.
Inspection Reports The IE inspection reports for the B&W plants contain numerous coments concerning problems and noncompliances that inay, collectively or indi-vidually prove to be relevant and significant.
2.
Tedesco Report LERs The Tedesco Report on Feedwater Transients (May 1979) lists numerous incidents that occurred'at B&W operating reactors that are to varying degrees similar to the TMI accident.
These events must be assessed collectively and individually as precursor events of the TMI accident.
3.
Licensee Regulatory Performance Evaluation IE has tried on at least three occasions to develop a system for evaluating licensee performance.
TMI and Met Ed were included in these evaluations 4.
Israel /Novak memo The note (January 10, 1978) is to the Reactor Systems Branch highlighting a potential problem due to the design of the pressurizer surge line.
The concern was based on the incident at Davis-Besse 1.
The note recommends that the bases for the design requirements be studied carefully for all CP reviews with the object of determining if the loop seal can be eliminated.
5.
Michelson report Michelson wrote a report for TVA in January 1978 that was determined not to be sufficiently significant to warrant fomarding to the NRC.
His concerns primarily focused on a lack of documented information which confirmed that the consequences of small LOCAs presently considered conservatively bound the consequences of very small breaks.
6.
Sternberg memo An IE inspector (Daniel Sternberg) wrote a memo to IE Headquarters requesting an assessment of the fact that the pressurizer electromat.ic relief valve is not safety-related. His concern was based on the incident where the valve failed open on loss of control power.
!!eadquarters responded that the event had already been covered in FSAR section 7.4.1.1.6.
7.
The technical review staff took the position, early in the operating license review stage, that the Auxiliary Feedwater System should be
" essential to plant safety" and should meet certain requirements which the earlier TMI-l design was not required to meet.
Further review of subsequent licensing decisions and actions will be necessary to determine what the final design of the AFS became and on what basis the design was i
justi fied.
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8.
Memo from IE: HQ to RG I dated 5/3/78.
f Concluded that no additional review of pressurizer relief valve opening at TMI-2 was warranted.
9.
Memo from IE to NRR dated 3/3/78 (Other memos also)
Recommended Tech. Spec. deletions in order for TMI-2 meet requirements for Mode-2 operation.
This may be related to obtaining commerical opera tion.
10.
Letter from NRR to Licensee dated 4/21/78 Granted relief from inservice inspection requirements.
Implication same as above.
11.
Ibeting Summary with Licensee dated 10/19/78 Staff aware that TMI-2 operating procedures will be modified to show manual closure of containment isolation valves after an accident. Also operator action was required to control feedwater to maintain level in steam generator for MSLB.
12.
Toledo Edison to NRR dated 12/22/78 Acknowledged voids in primary coolant system for loss of feedwater.
Performed a bounding safety analysis.
Related to Criswell letter.
Noted sensitivity of S.G. inventory.
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