ML19350E153
| ML19350E153 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/16/1981 |
| From: | Rosztoczy Z Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| ISSUANCES-OL, NUDOCS 8106170064 | |
| Download: ML19350E153 (7) | |
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.ca BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the matter of
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Docket No. 50-289 METROPOLITAN EDISON COMPANY,
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(Three Mile Island Nuclear
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NRC STAFF SUPPLEMENTAL TESTIMONY OF ZOLTAN R. ROSZTOCZY RELATIVE TO ENVIRONMENTAL QUALIFICATION OF EQUIPMENT IMPORTANT TO SAFETY (UCS CONTENTION 12)
UCS Contention 12 states in pertinent part that "TMI-1 should not be permitted to resume operation until all cafety-related equipment has been demonstrated to be qualified to operate as required by GDC 4.
The criteria for determining qualification should be those set forth in Regulatory Guide 1.89 or equivalent." GDC 4 requires that structures, systems, and components important to safety be designed to accommodate the ef fects of and tee compatible with the environmental conditions associated with normal operation and postulated accidents. For the purposes of this proceeding the equipment and environmental conditions of interest are those associated with accidents having a nexus to the TMI-2 accident. Thus, the equipment required to safely shutdown the reactor following a loss of feMwater and small break loss of coolant accident must be qualified to perform their safety functions when subjected to the environmental' cc;1ditions to which they would be exposed during the period in which those safety functions must be performed, t
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- As indicated in my previous testimony following Tr. 6927-A, the criteria against which the electrical equipment will be evaluated and the methods to be used to qualify the equipment are set forth in the D0R Diidelines and NUREG-0588.
The Commission has stated that these documents form the requirements which licensees and a,'licants must meet in order to satisfy the legal requirement of GDC 4.
By letter dated May 1,1981, the NRC requested information concerning the qualification of electrical equipment required to mitigate the consequences of a small break loss of coolant accident (SBLOCA). ThC licensae provided their response in an attachment to a May 18, 1981 letter, and references qualification information previously s'ubmitted by letter dated January 30, 1981.
In response to staff questions, the licensee provided supolemental information by letter dated June 5,1981.
The licensee's submittal identifies all Class IE electrical items, located in a SBLOCA harsh environment, that are required to bring the plant to a safe shutdown. An analysis was performed to define the most severe environ-mental conditions, i.e., temperature, pressure, humidity, chemical spray, submergence, and radiation levels, that the equipment located both inside and outside containment could be subjected to. The analysis considered a range of break sizes concurrent with a loss of offsite power, loss of l
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main feedwater, and a worst case single failure, i.e., the loss of one emergency diesel generator. The environmental conditions defined T
as a result of this analysis were then used to evaluate the qualiff-cation of the required electrical equipment.
i The staff has completed its review of the licensee's January 30, May 18, l
and June 5,1981, submittals. This review involved an evaluation of the list of equipment identified as required to mitigate the consequences of the ' BLOCA, the environmental (service) conditions specified for the S
4 equipment, and the qualification information provided for each piece of of equipment. The qualification information reviewed was data extracted from referenced documentation which contain detailed information concerning the qualification of the equipment.
- The staff is in the process of reviewing the supporting documentation referenced by the licensee and other qualification information that may be appifcable to equipment installed at TMI-1.
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As a result of its review, the staff agrees that the licensee has identified all the equipment, located in a harsh environment, required to safely shutdown the reactor in the ovent of a loss of feedwater/SBLOCA.
In its review of the environmental conditions specified for the equipment, the staff performed their own analyses and calculations to assess the adequacy of the licensee's specified environmental cond.itions. The staff determined that, with the exception of the radiation levels in the Auxiliary Building, th' most severa environmental conditions that could
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_4 result from this postulated event have been specified by the licensee.
The staff determined that a reasonable estimate ot' the radiation doses' in the Decay Heat Pump Rooms of the Auxiliary Building, normal plus accident, following a postulated SBLOCA would be greater than specified -
by the licensee. Therefore, in its review of the qualificatico infor-mation provided by the licensee for the electrical equipment, the staff used its own estimate of the radiation doses in the Auxiliary Building.
Using its own, higher estimate for th6 *adiation doses in the Auxiliary Building together with the other environmental conditions specified by the licensee, the staff reviewed the environmental qualification infor-mation submitted by the licensee. As a result of this review, the staff has determined that all the identified electrical equipment, located in the harsh environm'ent, have been demonstrated to be capable of performing their intended functions following a loss of feed-water /SBLOCA event, with the following exceptions. Two models of Conax Connectors have not been demonstrated to be qualified, two Limitorque motor operators that may become submerged have not been qualified for submergence; several items of equipment use materials that have calculated qualified lives of six years or less and, in some cases, the aging evaluations are still ongoing; the test report referenced by the licensee to demonstrate qualification of Foxboro pressure transmitters indicates that three of eight of the tested transmitters failed during the radiation test and further, the model tested is not the same model used at TMI-1; recent testing l
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on Limitorque operators with Reliance motors have resulted in f ailures of the dotors under more severe environmental conditions than expected for the event being analyzed at TMI-1 and the appli-cability of these tests to the valves and for the environmental conditions expected for THI-1 have not been evaluated.
For the two unqualified models of Conax Connectors, the licensee has committed to replace these with a qualified model prior to restart.
For the two motor operators, the licensee has provided justification acceptable to the staff for interim operation, which demonstrates that these motor operators will be capable of performing their containment isolation functions following this postulated event.
The licensee states that these valves will close prior to becoming submerged and that there is sufficient time for the operators to verify this by examination of the position indicator lights, as required by emergency procedures. As soon as the valves close, the valve motors are de-energized. Further, if the limit switches are shorted out by subsequent submergence, the control circuit fuse should blow. However, this results in a loss of the already verified valve positien indicator lights. The contactors which energize the actuator motors are located in a motor control center which is not subject to submergence and, therefore, submergence will not cause a change in valve position. The licensee also states l
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that submergence of any of the electrical components in the motor operators will not affect any other electrical system because of the isolation provided by the motor control center.
The staff recommends that as a condition of restart that the licensee commit to the following or, if not, that the Comuission require the licensee to:
1.
Replace materials with a qualified life of 1.5 years prior to restart.
2.
Prior to criticality, put in a place a maintenance and replacement program that will asure all materials with a qualified life of less than 40 years will be replaced when needed.
3.
Consider aging of the materials during the periods prior to instal-lation, during plant operation, and during the periods the plant is not operating in establishing the material replacement schedules.
4.
Coaplete the aging evaluations for the equipment still to be evaluated prior to exceeding 5% power operation and factor the results into the replacement program, if required.
5.
For the Foxboro pressure transmitters, reevaluate the referenced test report to justify the acceptance of the test results for demonstrating Foxboro pressure transmitters are qualified for the specified radiation levels. The failures occurred during a test to radiation levels several thousand times greater than the radiation levels expected as a result of i
a loss of feedwater/SBLOCA event. Also, provide justification for applying the test results to the transtnitter model installed in TMI-1 and provide the results of the above evaluation and justification to the NRC for review prior to exceeding 5% power operation.
6.
Evaluate the information made available to them prior to criti-cality, concerning the recent testing on Limitorque motor operators and determine wnether the results of that testing are applicable to the operators in TMI-1 for the event being analyzed.
Prior to exceeding 5% power operation, provide the results of this evaluation to the NRC for review.
Based on the results ot' its review, the commitments made by the licensee, and the recommended conditions of restart, as dis-cussed above, the staff concludes that the equipment necessary to cope with a loss of feedwater/SBLOCA event will have been demonstrated, prior to exceeding 5% power operation, to be capable of pertorming their safety functions when subjected to the environ-mental conditions to which they would be exposed during the period when their functions must be performed, shculd this event occur.
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Fy 1,1981 Docket No. 50-289 Mr. Henry D. Ilukill, Vice President and Director - TMI-1 Metropolitan Edison Company P. O. Box 480 Middletown, Pennsylvania 17057
Dear Mr. Hukill:
SLEJECT: TMI-1 RESTART ENVIRONMENTAL QUALIFICATION As part of our continuing review of the environmental qualification of equipment in TMI-1, we request that you provide the following infor-mation by May 15, 1981.
1.
List all of the essential systems and equipment required to bring the plant to a safe shutdown following a postulated loss of main feedwater transient and accompanying small-break LOCA. You should examine a break size gf approximately 0.5 ft.2 and a break size less than or equal to 0.01.ft.' to obtain the full spectrum of small breaks. The analyses should conside-the worst single failure in addition to the loss of off-site power.
2.
Define the parameters with the supporting bases of the environment generated by the accident in 1. above in containment and in the auxiliary building.
3.
For equipment idantified in 1. above, provide all of the environmental qualification infonnation needed to assure its operability under the environ-mental conditions described in 2. above. Applicable infonnation provided in your response to IE Bulletin 79-018 may be cited.
Sincerely, J n F. Stolz, Chief perating Reactors Branch #4 Division of Licensing cc:
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Metropolitan Edison Company NL1N Post Cffice Box 480 Middletown, Pennsylvania 17057 Wnter's Dirset Dial Nurnber May 18, 1981 s
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f Ot'fice of Nuclear Reactor Regulation Aten:
Mr. John F. Stolz, Chief d.. 5M,[g\\
Operating Reactors Branch No. 4
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Dear Sir:
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Three Mile Island Nuclear Stacian, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Equipment Qualification for Small Brcaks This letter is in response to your letter dated May 1, 1981 which requested information on environ = ental qualification for equipment needed to respond to design basis small break loss of coolant accidents (SB LOCA). Break cizes between 0.01 FT2 and 0.5 FT2 have been addressed considering a -loss of offsite power, loss of Main Feedwater, and a worst case single failure. The adverse environmental paramecers associated with the worst case SB LOCA have also been addreased. The qualifications of the various equipment has been referenced fron our response to IE Sulletin 79-01B dated January 30, 1981 (L1L 026).
Sincerely,
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dkill Director, TMI-l HDH:CWS:hh Attachment cc:
L. Barrett H. Silver R. Jacobs D
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Metropontan Edison Company is a Member of the General Pubhc Utilmes System