ML20209D217
| ML20209D217 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 07/02/1999 |
| From: | Jonathan Brown UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | Dyer J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| GDP-99-0123, GDP-99-123, NUDOCS 9907130071 | |
| Download: ML20209D217 (8) | |
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GDP 99-0123 U.S. Nuclear Regulatory Commission Mr. James E. Dyer Regional Administrator Region III 801 Warrenville Road Lisle. IL 60532-435i Portsmouth Gaseous Diffusion Plant (PORTS)
Docket No. 70-7002 Request for Temporary Enforcement Discretion
Dear Mr. Dyer:
The purpose of this letter is'fd request temporary enforcement discretion to allow continued plant operations while completing corrections to the Critiality Accident Alarm System (CAAS) cluster alarm setpoints to be in compliance with the Technical Safety Requiremen'ts (TSR) Surveillance
' Requirements. We anticipate that we will regain compliance within 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> from the discovery of the event (Monday evening at midnight). The enforcement discretion is necessary to allow plant operations to continue in those facilities that have a 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> time limit for remaining in the TSR Limiting Conditions for Operation (LCO's) associated w'th a CAAS outage. Within these facilities,
. the CAAS with its current settings is still capable of detecting the minimum accident of concern, as required by the TSR Basis Statement in addition, the TSR LCO Actions will still be met and personnel access will be restricted to personnel with Electronic Personal Dosimeters (EPDs) which provide additional capability for detection of a criticality.
Therefore, USEC is seeking enforcement discretion to continue plant operations in accoidance with the TSR LCO actions and with the existing CAAS alarm settings until the setpoint adjustments can be completed to provide compliance with the TSR Surveillance. Specifically, USEC is requesting discretion to continue operation in this mode for a period of up to 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> from the date of discover). The Enclosure provides the technical justification and safety basis for this request in accordance with NRC Inspection Manual Chapter 9900.
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9907130071 990702
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United Scares Enrichment Corporation Portsmouth Gaseous DifTusion Plant P.O. Box 628. Piketon. OH 45661 L
Should you have any questions regarding this matter, please contact Mr. Pete Miner at (740) 897-2710. There are no new commitments contained in this submittal.
Sincerely,
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J.M. Brown General Manager l
Enclosure:
Justification for Request for Enforcement Discretion Mr. Patrick L. Hiland - NRC Region III Office cc:
NRC Resident Inspector - PORTS Mr. Robert C. Pierson. NRC HQ Mr. Randall M. DeVault, DOE U.S. Nuclear Regulatory. Commission.
Attention: Document Cofitrol Desk Washington, D.C. 20555-000I 4
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ENCLOSURE GDP 99-0123 Justification for Request for Temporary Enforcement Discretion w..
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Enclosure to GDP 99-0123 Page1of5 JUSTIFICATION FOR REQUEST FOR TEMPORARY ENFORCEMENT DISCRETION 1.
THE CERTIFICATE CONDITION THAT WILL BE VIOLATED.
The TSRs gove.ning operation of the CAAS specify that the CAAS must be operable while parforming fissile material operations in various facilities. The CAAS units do not meet the surveillance requirement in these TSRs in that they are not currently set to alarm at 5 mrad /hr.
USEC desires to continue plant operations within the TSR LCOs with the existing CAAS alarm settings until the alarm setpoints adjustments can be completed for a period of up to 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> from the date ofdiscovery. Several facility TSRs limit the time that the facility can remain in the TSR LCO Actions to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. The TSRs are as follows: 2.2.3.2, 2.4.3.1, 2.5.3.1, and 2.7.3.2.
2.
THE CIRCUMSTANCES SURROUNDING THE SITUATION, INCLUDING ROOT CAUSES, NEED FOR PROMPT ACTION AND IDENTIFICATION OF ANY RELEVANT HISTORICAL EVENTS.
On July 1,1999, while inEe'stigating a new radiation calibration neutron source in the Radiation Calibration Facility (Rad Cal), an engineer pulled up the basis spreadsheet calculations for the calibration of the CAAS clusters on the Rad Cal Computer. This was part of an evaluation of L
discrepancies between the calibration calculations and his calculations for the new source. While performing this evaluation, he discovered the following:
The method ofcalibration for the CAAS clusters by procedure set the cluster at a point on the u.
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beam range where the neutron field strength is calculated to be 5 mrad /hr in air. The procedure calls for adjusting the cluster to 35,000 counts / minute (cpm) at this field strength. The P
procedure then calls for the alarm setpoint to be set to a vahse between 35,000 and 60,000 cpm.
Typically the clusters are set mid-range but could be as high as 60,000 cpm. Since the 35,000 cpm is equivalent to the TSR limit of 5 mrad /hr in air, the procedure results in the cluster alarms being set at a value exceeding the TSR surveillance limit.
The value could be as high as 5x60K/35K or 8.57 mrad /hr in air. The lab set up dose rate has been checked with independent instmments calibrated by offsite facilities and the field strength is accurate. The apparent cause l
- of the problem was an error in the spr,adsheet calculations used in the calibration of the CAAS l
clusters.
The problem was reported and the entire CAAS system was declared inoperable. The EOC was activated and an " Alert" was declared at 0040 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> o~n July 2,1999, based on the declaring of the system inoperable.
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3.
THE SAFETY BASIS FOR THE REQUEST, INCLUDING AN EVALUATION OF THE SAFETY SIGNIFICANCE AND POTENTIAL CONSEQUENCES OF THE PROPOSED COURSE OF ACTION, INCLUDING ANY QUALITATIVE RISK ASSESSMENT.
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Encimure to GDP n-0123 Page 2 of 5 The accident of concern associated with this request is a criticality accident. The CAAS does not provide any preventive function for a criticality accident; rather it provides for mitigation of effects to onsite workers by sounding an evacuation signal based on detecting the elevated radiation levels accompanying such an accident. The SAR identifies a criticality as having only potential onsite impacts with no effect on the public.
The safety basis for the CAAS is that " clusters are designed and calibrated to detect and alarm on a minimum credible criticality accident ofconcern, defmed as producing an integrated total dose of 20 Rads in one minute at two meters from the reacting material. This system will provide an audible signal in the event of a criticality that will alert personnel to evacuate the immediate work areas.. ". In the facilities where enforcement discretion is needed, the CAAS clusters, as currently set (including calibration uncertainties), will detect the minimum credible riticality accident ofconcem and provide the required alarm. While the coverage ofindividual asters is reduced, the clusters still provide detection coverage for the buildings in question.
'T he degree of duster coverage overlap is reduced. White the alarm settings do not match the TSR surveillance level o'f 5 mrad /hr, the current alarm settings have been evaluated against the analyses of anticipated radiation levels from the minimum acciden_t of concern and the clusters will detect and provide the alarm as required by the TSR Basis. As such, plant personnel are still provided with the requisite protection from the minimum credible accident of concern. For those aiticality events analyzed in the SAR, which are larger than the minimum credible accident used for CAAS design and calibration, multiple clusters would alarm. In addition, in compliance with TSR LCOs, access to these facilities is limited and all personnel entering these facilities are required to have an EPD to provide personal alarming capability. With these measures in place, there is no undue risk to plant personnel.
4.
THE BASIS FOR THE CERTIFICATE HOLDERS CONCLUSION THAT THE NONCOMPLIANCE WILL NOT BE OF POTENTIAL DETRIMENT TO THE PUBLIC HEALTH AND SAFETY, THE ENVIRONMENT, SAFEGUARDS, OR SECURITY, AND THAT NEITHER AN USQ NOR A SIGNIFICANT HAZARD CONSIDERATION IS INVOLVED.
The responsein Question 3 shows that the current condition of the CAAS does not provide an increased risk of a criticality accident. There is no offsite impact predicted from a criticality accident and the CAAS provides no protective function for the public health and safety. As noted above, while the CAAS alarm setpoints do not meet the TSR surveillance requirements, they are adequate to detect a minir.1um accident of concern in the buildings where enforcement discretion is required and to provide an alarm to evacuate the area of concern for mitigating exposure ofpersonnel. In addition, the TSR LCO actions implemented restrict personnel access to the facility and require any personnel entering the facility to be equipped with an EPD.
Therefore, there is no potential detriment to the public health and safety.
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r Enclosure to GDP 99-0123 Page 3 of 5 Based on the following conclusions, there is no Unreviewed Safety Question:
1.
The proposed operation will not increase the probability of occurrence of an accident previously evaluated in the SAR.
2.
The proposed operation will not increase the consequences of an accident previously evaluated in the SAR. The CAAS in its current condition remains capable of meeting the mitigative function by detecting a minimum accident of concern and providing the alarm to direct evacuation of plant workers from the area of concern. In addition, the TSR LCO actions limit personnel access to these facilities and require EPDs for entry. Continued operation during the period required for resetting of the CAAS alarm setpoint to comply with the TSR surveillance will not increase the consequences of a criticality.
3.
The proposed operation will not increase the probability of occurrence of a malfunction of equipment important to safety previously evaluated in the SAR.
The proposed operation will not increase the consequences of a malfunc+' e of equipment 4.
m important to safety previously evaluated in the SAR. The current CAAS settings are adequate to detect the minimum credible accident and provide the alarm so evacuation of personnel from thrafrected area will occur. In addition, the TSR LCO action restrict
. personnel access and require EPDs for entry into these areas. Continued operation during this period cannot impact the consequences of a malfunctio~n'of equipment imponant to safety.
5.
The proposed operation will not create the possibility of an accident of a different type than any previously evaluated in the SAR. Continued operation during this period will not result in any new activities, therefore there is no possibility of an accident of a different type than any previously evaluated in the SAR.
6.
The proposed operation will not create the possibility of a different type of malfunction of equipment important to safety than any previously evaluated in the SAR. Continued operation during this period will not result in any new activities, therefore there is no possibility of a different type of malfunction of eguipment important to safety.
7.
The proposed operation does not reduce the margin of safety as defmed in the supporting bases documents for any TSR because the TSR LCOs are still being met and the CAAS provides adequate detection coverage for the facilities covered by the LCOs where enforcement discretion is being requested.
Based on the following conclusions, there is no Significant Hazard Consideration:
- 1. The proposed operation has no impact on any efIluents released offsite. As discussed abave, the consequences of a criticality accident will remain within those analyzed in the SAR.
- 2. The proposed operation will not result in an increase m individual or cumulative, occupational radiation exposure. Continued operation during this period has no etr t on the probability ec ofoccurrence of a criticality accident at PORTS. As discussed above, the consequences of
Enclosure to GDP 99-0123 Page 4 of 5 a criticality accident will not be affected by this operation. Therefore, there will be no increase in individual or cumulative occupational radiation exposure.
- 3. This request involves continuing existing operations within the TSR LCOs and adjusting the alarm setpoint on the existing CAAS clusters. Therefore, there is no significant construction impact as a result of this enforcement discretion request.
- 4. As discussed above, neither the probability nor the consequences of a criticality accident will be affected by continued operation during this period. Therefore, there is no increase in the potential for, or radiological or chemical consequences from, previously analyzed accidents.
- 5. Continued operation during this period will not result in any new activities, therefore there is no possibility of an accident of a different type than any previously evaluated in the SAR
- 6. The margins of safety associated with the CAAS TSRs remain within what is described in the Basis. The alarm setpoint is above the TSR surveillance requirements but the CAAS will still detect the minimum credible accident and provide the alarm. In addition, the TSR I CO actions will be met by restricting personnel access to these areas and by requiring at EPD for entry. Therefore, the margin of safety is not impacted by continued cperation as requested.
- 7. As discussed above, neither the probability nor the consequences of a criticality will be affected by continued operation during this period. Therefore, continued operation during this period will not result in an overall decrease in the effectiveness of the plant's safety, safeguards or security programs.
5.
THE BASIS OF THE CONCLUSION THAT THE NONCOMPLIANCE WILL NOT INVOLVE ADVERSE CONSEQUENCES TO THE ENVIRONMENT.
The proposed operation has no impact on any efiluents released offsite.
6.
ANY PROPOSED COMPENSATORY MEASURES.
As previously stated, this request proposes to continue operation within the TSR LCOs until the CAAS alann setpoints are adjusted to meet the TSR surveillance requirement. Since the CAAS will detect a minimum credible accident and provide the alarm required for personnel protection and the TSR LCO actions restrict personnel access and require EPDs for entry, no compensatory measures are necessary.
7.
THE JUSTIFICATION FOR THE DURATION OF NONCONFORMANCE.
USEC is preparing a procedure to adjust the alarm setpoin. in the field for the 54 clusters involved in the TSRs where enforcement discretion is required. We will begin these adjustments immediately and we intend to complete this effort within 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> from time of discovery. The clusters adjustments will be prioritized in the recovery plan. Since the CAAS 'provides adequate
e Enclosure to GDP 99-0123 Page 5 of 5 alarm coverage and we are continuing to restrict access and use EPDs, we believe that the additional time presents no risk to plant personnel or to the public.
8.
A STATEMENT THAT THE REQUEST HAS BEEN APPROVED BY THE PLANT OPERATIONS REVIEW COMWTTEE (PORC).
The PORTS PORC approved this request for temporary enforcement discretion on July 2,1999.
9.
THE REQUEST MUST ADDRESS HOW ONE OF THE NOED CRITERIA FOR APPROPRIATE PLANT CONDITIONS SPECIFIED IN SECTION B IS SATISFIED.
Criteria B.2.1.a. in NRC Inspection Manual 9900, NOEDs for GDPs states: "For ongoing
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operations at the GDP, the NOED is intended to: (a) avoid undesirable transients as a result of l
forcing compliance with the TSR/ certificate condition and, thus, minimize potential safety, environmental, safeguards, or security consequences and operational risks:" The exceedance of f
the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> limitation on remaining in LCOs could result in potential shutdown of the major enrichment process, withdrawal and feed facilities; this could introduce potential se~ere transients to the GDP ivhich could present additional safety and operational risks. Since the plant will remain within the TSR LCOs and the CAAS is capable of detecting a criticality
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accident, the lowest risk is to continue plant operations within the7SR LCOs until the setpoint adjustments are completed. Therefore, t e granting of tempora y enforcement discretion would N
prevent a safety and operational risk without corresponding safety, safeguards, security or environmental benefits.
- 10. IF A FOLLOW-UP TSR/ CERTIFICATE AMENDMENT IS REQUIRED, THE NOED REQUEST MUST INCLUDE MARKED-UP TSR PAGES.
THE ACTUAL TSR/ CERTIFICATE AMENDMENT REQUEST MUST FOLLOW WITHIN 48 HOURS.
No TSR/ Certificate Amendment is required.
- 11. ANY OTHER INFORMATION THE STAFF DEEMS NECESSARY BEFORE MAKING A DECISION TO EXERCISE ENFORCEMENT DISCRETION.
. PORTS plans to downgrade the " Alert" upon identification of a success path to completing the cluster setpoint adjustment coincident with receiving enforcement discretion. The success path will be identified as in place when the procedure has been comrleted and at least one cluster has
' been retumed to service. The Crisis Manager will authorize the downgrade of the " Alert". No other information has been requested by the Staff at this time.
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