ML20236F522
| ML20236F522 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 06/30/1998 |
| From: | Leddy R AFFILIATION NOT ASSIGNED |
| To: | |
| Shared Package | |
| ML20236F499 | List: |
| References | |
| NUDOCS 9807020196 | |
| Download: ML20236F522 (7) | |
Text
-.
Docket No. 50-336 B17356 l
i l
1 Attachment 3 l
- l. Millstone Unit No. 2 l
l Independent Assessment of the UGS Personnel Contamination Event at Millstone Station Unit 2 i
l June 1998 9907020196 990630 --,
PDR ADOCK 05000336' S PDR:
Independent Assessment ofthe UGS Personnel Contamination Event at MILLSTONE STATION UNIT 2 June,1998 Final Report Performed by:
Mr. Robert E. Leddy Millennium Services, Inc.
2520 E. Piedmont Road, Suite F-109 Marietta, GA 30062 (770) 955-6395 l
MILLENNIUM SERVICES, INC.
Leading the way...
l L1_----------------_-------------
w i
Executive Summary An independent assessment, of the events that led to the generation of Condition Report M2-98-1533, was performed by Mr. Robert Leddy of Millennium Services, Inc. during the period June 9-12,1998. The objective of the assessment was tr, evaluate the event )
and the station's response, as well as to draw conclusions and mse recommendations as appropriate. In addition, the assessor was asked to compare his conclusions with those of the Event Review Team (ERT), which was chartered to review the event described in CR M2-98-1533. l The assessor concluded that there is inadequate documentation of surveys of the work I platform prior to allowing workers to access the platform. There also appears to be a general lack ofdocumentation describing the rationale used in reaching decisions regarding HP actions where procedures allow the use of discretion. This problem is believed to be due in part to excessive. subjectivity of some procedures. RP supervisory resources also appear to be less than adequate to ensure success given the levelbf ~
discretion that exists in these procedures.
In general, the extended shut down has allowed the radiological conditions in the plant to stabilize and has allowed RP personnel to gain a good understanding of the conditions that exist. During this event, some decisions were made not to perform surveys, because it was felt that there would be no value added. While it is prudent to make decisions
. based on knowledge and experience, it is important to document the facts on which these decisions are based. This information was not recorded as well as it should have been. l In addition, there is no formal program requiring a routine review of the radiological l l
characteristics of the plant to identify changes and evaluate the impact of these changes on program elements.
The ERT was very thorough in its review of the event, and was proactive in causing
~ actions to be taken that were important for event clo'sure. The review was for the most part objective, although some subjectivity was exercised by the team with respect to the identification of apparent 10CFR20 violations and the depiction of Unit 2 HP and NO ;
interface.
qqui -iug f, , ,. ,
- Methodology -
The Condition Report, and the volumes of data, accumulated by the ERT, were reviewed during this assessment. In addition, the assessor spoke with ERT members in order to obtain clarification of responses they received during interviews with personnel involved in the event. Additional information was requested from the Health Physics group,
- predominantly to gain an understanding of how this Upper Guide Structure activity has been performed in the past. Interviews were conducted with Ms. Maria Nappi and Mr.
Don Del Core to understand their roles in the event, as well as to gain some insight into the rationale behind their decisions.
Conclusions .
~ 1. There is no documented survey that shows the radiological conditions of the work !
platform prior to, or during the work evolution, with the exception of air sainplirig
- data. The RWP that governed the work activity required that a survey be taken of the
. work platform prior to entry by the workers. According to the technicians that were providing job coverage, dose rate surveys were performed of the platform during movement, prior to the workers entering the platform, and while the ICl plate was
- being lified. None of these surveys were documented and therefore did not have the benefit of a review. It was decided not to take contamination sur veys prior to or during the work evolutions because the surfaces would be wet and therefore the survey may not have provided useful data. The survey of the work platform, that was performed ~on April 27,1998, which apparently served as.the basis for the RWP and pre-job briefing, provided incomplete documentation of the location of contamination and only provided levels of contamination. This survey did not include an evaluation of the presence of hot particles.
. There appears to be less than adequate programmatic guidance provided to HP technicians regarding the documentation of surveys. This conclusion is based on a ,
conversation with the RP Supervisor, during which he stated that he would have '
preferred it if the technicians documented the surveys they conducted of the platform. j
- 2. Procedure RPM 2.11.1," Survey and Documentation of Personnel and Clothing",
sections 4.3.1 and 4.1.1 state " IF radiological conditions warrant OR directed by
- Health Physics Supervision, SURVEY for alpha contamination. ." Alpha L contamination was known to be present on the components with which these workers
' were involved, based on the survey that was performed on April 27,1998. It was determined by RP supervision however, that the ratios of beta-gamma to alpha, which are very high, were consistent with the ratios that have been seen since shutdown.
Based on this fact, coupled with the low levels of beta-gamma contamination present on the workers, they determined that radiological conditions did not warrant surveying the individuals for alpha contamination. The bases for this decision were not documented.
2 i _ _ _ _ _ _ - _ - _ _ - _ - _ _ _ _ _ _ _ _ _-
- t. % .
l 3. Attempts were made to have whole body counts immediately, but those attempts were not successful. The decision was made by the RPM to perform a WBC when the workers returned to site several days later. Based on conversations with the RPM, the decision was based on the low levels and physical characteristics of the contamination present on the workers face. The direction provided in Procedure RPM 1.3.12 is to perform a whole body count if workers have facial contamination. The procedure does not specify the time frame in which this evaluation must be performed; I therefore, there was no procedural violation. Given the situation it would have been a better practice to perform the WBC before the workers left the site.
The lack of available qualified whole body count operators contributed to allow the workers to leave site prior to receiving a whole body count.
- 4. ALARA Exposure Review No. A296009 specified the use of HEPA ventilation when air samples indicate the potential for airborne activity greater than 0.3 DAC.' Ba' sed on discussions with RP supervision determined that the potential for airborne activity greater than 0.3 DAC did not exist based on historical knowledge, and the fact that the platform was going to be wet. However, this rationale was not documented.
Based on a review of the air sample data from this activity.and the previous activity, the use of HEPA ventilation as an engineering control was not required by the ALARA Exposure Review.
- 5. Procedure RPM 2.10.2," Air Sampling Counting and Analysis", provides good direction on how to analyze air samples, along with a trigger value for analyzing the air sample for alpha. The air samples taken during the work activities in question, did not meet the trigger value contained in RPM 2.10.2, and therefore were not analyzed for alpha.
Based on conversations with RP management personnel, although alpha is present in the unit, it has never presented any significant problems from a personnel health and safety perspective. The quantity of alpha that has been found is orders of magnitude lower than the corresponding quantity of beta-gamma and the levels or characteristics have not changed over the years. According to RP management, this is especially true since the shutdown, There is a technical basis document, Memo MP-HPO-93311," Preliminary Guidance for Evaluation of Air Samples for Long Lived Gross Alpha Activity with Regard to the Revised 10CFR20", dated February 17,1993, that provides the rationale for the trigger value used for analyzing air samples for alpha.
There does not appear to be any well-documented evaluations that suggest that the information contained in this document is still valid and applicable to Unit 2. If this is still a valid technical basis document, and the evaluator has no reason to say that it isn't, the fact that the air samples were not evaluated for alpha, should not result in a regulatory violation.
There is less than adequate procedural guidance provided to HP technicians regarding the analysis of alpha contamination on stiuctures and equipment.
3
e 4A*
- 6. It appears as though RP management does not believe that the amount of alpha
, contamination on the refuel floor presents a worker health and safety concern. If this is in fact the case, a formal surveillance program should be established that analyzes the risk and provides suitable documentation.
l 7. The procedures that were reviewed during the course of this assessment were found to be of reasonable quality, however, they leave many decisions to the discretion of RP supervision. It was explained to the assessor that this was a conscious decision since the procedures are common among all the units, and therefore should not be based on the most restrictive condition. This decision appears to be well founded, however, the RP supervisory resources necessary to ensure success of the program may not be sufficient. There is currently only one RP Supervisor to oversee RP operational activities. This event occurred on back shift, when there was no RP supervisory presence.
Additionally, there does not appear to be any requirement or expectation toiloctiment the rationale utilized in making decisions. While this makes it difficult to audit / assess why things were done, and may make it difficult to defend actions to regulatory authorities, the more important concern may be protection from future litigation.
In order to evaluate the effort put forth by the ERT, a debrief was conducted with the team on June 12,1998, after the conclusion:; presented in this report were provided to Mr.
Steve Heard. In addition, a draft copy of the ERT Report was provided for evaluation.
The review performed by the ERT was very thorough; both in researching the event itself, but also by performing a comparison of this event and the CY Transfer Canal Event that occurred in 1996. The ERT also performed a review of Unit I and Unit 3 program elements to identify any generic issues that may exist at the Millstone Station.
The conclusions reached by the ERT were, for the most part, objective and in good agreement with the conclusions reached during the independent assessment. In some cases, subjectivity was evident but only in defining the severity of the conclusions.
Specifically, the ERT used the term violaticn of 10CFR20.1201 and 1503 with respect to the failure to conduct and document the surveys of the work platform. In this regard, it is not believed that this use of subjectivity detracted from the efforts of the ERT rather was used to help frame the possible consequences of the event. The classification of conversations between HP management and Nuclear Oversight as being " intimidating and harassing" also appear to be somewhat subjective, however, these conversations were not witnessed or assessed during this assessment.
The ERT was chartered on June 4,1998, which was a full week after the Condition Report was generated. It was not apparent during this independent assessment that the delay impacted the ERT's evaluation of this event. The ERT caused several actions to be performed by the Unit 2 RP group, including an Internal Dose Assessment, and an evaluation of contamination, present on the work platform, for alpha activity. These actions, which represent a questioning attitude, were appropriate and represent good Health Physics practices, should have been performed by the RP group. The fact that the ERT was not formed until June 4,1998 caused an additional delay in these actions being performed.
4
cf%.
6-l
!. Recommendations
- 1. Provide clear guidance to RP technicians regrading the need to document surveys.
- 2. . Implement a log-keeping program to record decisions and corresponding bases.
- 3. Ensure the availability of trained and qualified WBC operators, and consider incorporating a time frame for conducting bioassay.
- 4. Provide procedural guidance to RP technicians regarding the need to analyze for surface alpha contamination.
- 5. Implement a routine program to evaluate the technical bases for program elements to ensure that they remain valid.
s .
- 6. Evaluate RP supervisory resources to ensure they are appropriate given the amount of L- discretion allowed in procedures.
! l
. J
( .'
I I
l 9
5
- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _